JPWO2020149206A1 - Acrylic resin film manufacturing method - Google Patents

Abstract

The method for producing an acrylic resin film is a method for producing an acrylic resin film containing an acrylic resin and rubber particles, in which the glass transition temperature (Tg) is in the range of 120 to 180 ° C. and the weight average molecular weight is 30. A step of preparing a dope containing 10,000 to 4 million acrylic resins and rubber particles having a core-shell structure, and the dope is filtered by filtering using a filter having a filtration accuracy in the range of 5 to 100 μm. The step of preparing the web, the step of casting the dope after filtration on the support to peel off the web, and the step of drying the web, and at an angle of 75 degrees with respect to the acrylic resin film. When measured under the condition that parallel rays are incident and the optical comb width is 0.125 mm, the transmitted imageability C value is within the range of 80 to 100%.

Description

The present invention relates to a method for producing an acrylic resin film, and more particularly to a method for producing a homogeneous acrylic resin film that is highly durable, tough, and does not cause optical disturbance on the surface and inside.

In recent years, only optical films such as polarizing plate protective films and retardation films for liquid crystal display devices and organic electroluminescence display devices, which are display devices, and base films such as touch panel base films and gas barrier base films can be used. However, there is a great demand for flexible resin films that realize high transparency, high functionality, and weight reduction, such as substrate films for nanoimprints and substrate films for flexible electronic circuits.

Among them, an acrylic resin is preferably used as an optical film because it exhibits excellent transparency and dimensional stability in addition to low hygroscopicity.
In particular, since the demand for tougher and more durable films is increasing, acrylic resins are required to have a high glass transition temperature and a high molecular weight.
A technique is disclosed in which the amount of volatile components volatile is controlled by temperature by increasing the methyl methacrylate ratio of the acrylic resin to a high molecular weight, the heat resistance is excellent, and streaks and step unevenness are suppressed (for example, Patent Documents). 1).

Further, it is known that the acrylic resin film contains rubber particles dispersedly in order to absorb impact and improve the strength. However, the acrylic resin has a high molecular weight and a molecular weight distribution, and the rubber particles are dispersed and aggregated. The interaction with the acrylic resin is also affected by the fact that the dope has a high viscosity and has a local viscosity distribution. By having a local viscosity distribution in this way, a minute fluidity distribution, a leveling distribution, and a hardness distribution of the dry film occur in the solution casting, and minute irregularities are formed on the film surface to achieve a mapping property (for example, for example). The linearity of the fluorescent lamp reflected image reflected on the film surface) deteriorates. Further, the rubber particles have a primary particle size that is considered so as not to cause sufficient light scattering, but if there is coarse soft aggregation or coarse density distribution, the rubber particles become apparently coarse particles, which is an optical lens. In order to exert the effect, not only the unevenness of the surface but also the distribution inside the film causes optical disturbance.
On the other hand, optical films have been developed for electronic circuit boards such as touch panels and window films for flexible displays, and in addition to the applications of polarizing plate protective films and retardation films whose main issues are transparency and adhesiveness. Since it has come to be required by adding the suitability of wet / dry coating and nano-fine processing, a surface structure without fine unevenness is required.

International Publication No. 2015/0647332

The present invention has been made in view of the above problems and situations, and the solution thereof is to provide a method for producing a homogeneous acrylic resin film which is highly durable, tough and does not cause optical disturbance on the surface and inside. be.

In order to solve the above problems, the present inventor shall keep the conditions for adding rubber particles having a core-shell structure, the filtration accuracy of the dope, and the transmission imageability within a certain range in the process of examining the cause of the above problems. As a result, we have found that it is possible to provide a method for producing a homogeneous acrylic resin film that is highly durable, tough, and does not cause optical disturbance on the surface and inside, and has arrived at the present invention.
That is, the above-mentioned problem according to the present invention is solved by the following means.

1. 1. A method for producing an acrylic resin film containing an acrylic resin and rubber particles.
A step of preparing a dope containing an acrylic resin having a glass transition temperature (Tg) in the range of 120 to 180 ° C. and a weight average molecular weight of 300,000 to 4 million and rubber particles having a core-shell structure. ,
A step of filtering the dope using a filter having a filtration accuracy in the range of 5 to 100 μm to prepare the dope, and a step of preparing the dope.
The step of spreading the dope after filtration on the support and peeling off the web,
It has a step of drying the web, and
An acrylic resin having a transmitted maple property C value in the range of 80 to 100% when measured under the condition that a parallel ray is incident on the acrylic resin film at an angle of 75 degrees and the optical comb width is 0.125 mm. How to make a film.

2. 2. The method for producing an acrylic resin film according to item 1, wherein the content of the rubber particles having a core-shell structure is within 5 to 20% by mass with respect to the acrylic resin film.

By the above means of the present invention, it is possible to provide a method for producing a homogeneous acrylic resin film which is highly durable, tough and does not cause optical disturbance on the surface and inside.

Although the mechanism of expression or mechanism of action of the effect of the present invention has not been clarified, it is inferred as follows.
In the present invention, the glass transition temperature (Tg) of the acrylic resin, the weight average molecular weight, the addition conditions of the rubber particles having a core-shell structure, and the filtration accuracy of the dope are controlled within a predetermined range, and the transmission imageability is controlled. By keeping the temperature within a predetermined range, the viscosity of the dope is controlled to an appropriate state, and the local viscosity distribution at the place in the dope is reduced and homogenized. It is presumed that the hardness distribution of the dry film was reduced and the problem of the present invention was solved.

Schematic diagram of a manufacturing apparatus used in the method for manufacturing an acrylic resin film of the present invention. Schematic diagram of a solution casting film forming apparatus for carrying out the method for producing an acrylic resin film of the present invention. Schematic diagram of forming an intervening membrane between the flow membrane and the endless support Schematic plan view schematically showing an example of a tenter stretching apparatus used in the method for producing an acrylic resin film of the present invention. Schematic plan view schematically showing another example of the tenter stretching device. Schematic diagram of the tenter clip used in the present invention Schematic diagram for explaining diagonal stretching used in the method for producing an acrylic resin film of the present invention. Schematic diagram of the stretching apparatus of one embodiment of the present invention Side view showing the outline of the winding device Top view showing the outline of the winder Explanatory view (A) showing the relationship between the welded portion of the band and the formed region on the welded portion of the film is a plan view showing the relationship between the welded portion of the band and the cast film, and (B) is a plan view of the film. Schematic diagram from the drying process to the winding process Explanatory drawing which shows the static elimination method using a blast type static elimination device. Perspective view showing acrylic resin film and packaging material Perspective view showing embodiment of a package Explanatory drawing of operation of this embodiment Perspective view showing the state of attachment of the film tip to the winding core. Top view showing the state of attachment of the film tip to the winding core Cross-sectional view of the film wound three times around the tip of the film Sectional drawing of the second embodiment Sectional drawing of the third embodiment Cross-sectional view of the film winding state of the same embodiment Sectional drawing of 4th embodiment A plan view showing a state in which the film tip is attached to the winding core in another embodiment in which the tilt angle of the film tip is changed. Schematic diagram for explaining a method of manufacturing a winding core by a filament winding method. Schematic diagram for explaining a method of manufacturing a winding core by a sheet winding method. The figure which shows the film roll which wound the tape around both ends of a film The figure which shows the surface and the cross section of the tape which was embossed or slit. (A) is a schematic schematic diagram of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a vertical cross-sectional perspective view of the film of (A) with respect to the width direction, and (C) is a perspective view. Schematic diagram for explaining the embossed region in the film of (A) (A) is a schematic schematic diagram of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a vertical cross-sectional perspective view of the film of (A) with respect to the width direction, and (C) is a perspective view. Schematic diagram for explaining the embossed region in the film of (A) (A) is a schematic schematic diagram of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a vertical cross-sectional perspective view of the film of (A) with respect to the width direction, and (C) is a perspective view. Schematic diagram for explaining the embossed region in the film of (A) (A) is a schematic schematic diagram of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a vertical cross-sectional perspective view of the film of (A) with respect to the width direction, and (C) is a perspective view. Schematic diagram for explaining the embossed region in the film of (A) Schematic diagram of film production line Top view of the winder Graph showing the relationship between film stress and winding length in the circumferential direction of the winding core Explanatory drawing of film stress in the circumferential direction of the winding core Graph showing the relationship between the surface pressure and the winding length when winding with straight winding Graph showing the relationship between the surface pressure and the winding length when winding with oscillate winding Flow chart showing the operation of the winder Schematic diagram showing an example of a film forming line Schematic diagram showing an example of a plasma CVD apparatus used for forming an inorganic gas barrier layer. The figure which shows the pattern exposure at the time of manufacturing of the anti-counterfeit medium A Enlarged view of the pattern observed on the anti-counterfeit medium A via the polarizing plate The figure which shows the photomask used in the pattern exposure at the time of manufacturing of the anti-counterfeit medium B The figure which shows the pattern of the slow phase axis of the anti-counterfeit medium B

The method for producing an acrylic resin film of the present invention is a method for producing an acrylic resin film containing an acrylic resin and rubber particles, in which the glass transition temperature (Tg) is in the range of 120 to 180 ° C. and the weight average. A step of preparing a dope containing an acrylic resin having a molecular weight of 300,000 to 4 million and rubber particles having a core-shell structure, and filtering the dope using a filter having a filtration accuracy in the range of 5 to 100 μm. It has a step of preparing a dope, a step of spreading the dope after filtration on a support to peel off the web, and a step of drying the web, and at 75 degrees with respect to the acrylic resin film. When measured under the condition that parallel light rays are incident at an angle of 1 and the optical comb width is 0.125 mm, the transmitted imageability C value is in the range of 80 to 100%.
This feature is a technical feature common to each of the following embodiments.

As an embodiment of the present invention, the content of the rubber particles having the core-shell structure is preferably 5 to 20% by mass or less with respect to the acrylic resin film from the viewpoint of exhibiting the effect of the present invention.

Hereinafter, the present invention, its constituent elements, and modes and embodiments for carrying out the present invention will be described. In the present application, "~" is used to mean that the numerical values described before and after it are included as the lower limit value and the upper limit value.

[Outline of Manufacturing Method of Acrylic Resin Film of the Present Invention]
The method for producing an acrylic resin film of the present invention is a method for producing an acrylic resin film containing an acrylic resin and rubber particles, in which the glass transition temperature (Tg) is in the range of 120 to 180 ° C. and the weight average. A step of preparing a dope containing an acrylic resin having a molecular weight of 300,000 to 4 million and rubber particles having a core-shell structure, and filtering the dope using a filter having a filtration accuracy in the range of 5 to 100 μm. It has a step of preparing a dope, a step of spreading the dope after filtration on a support to peel off the web, and a step of drying the web, and at 75 degrees with respect to the acrylic resin film. When measured under the condition that parallel light rays are incident at an angle of 1 and the optical comb width is 0.125 mm, the transmitted imageability C value is in the range of 80 to 100%.

In the present invention, the glass transition temperature (Tg) of the acrylic resin, the weight average molecular weight, the addition conditions of the rubber particles having a core-shell structure, the filtration accuracy of the dope and the transmission imageability are set within the above ranges to dope. The viscosity of the resin is controlled to an appropriate state, and the local viscosity distribution in the place in the dope can be reduced and homogenized, so that the fine fluidity distribution, leveling distribution, and dry film hardness in the solution casting can be achieved. It is possible to provide a method for producing a homogeneous acrylic resin film having a reduced distribution, high durability, toughness, and no optical disturbance on the surface and inside.

<Fine particles and rubber particles>
The acrylic resin film according to the present invention contains rubber particles as an essential component among the fine particles. However, fine particles other than rubber particles can also be preferably used as appropriate. Particularly preferred is a matting agent used as an anti-blocking agent for films. The fine particles used as a matting agent include inorganic fine particles and organic fine particles. Acrylic-based materials are preferably used for organic fine particles, and some of them are difficult to distinguish from the rubber particles of the present invention. Therefore, the rubber particles of the present invention are defined to have a glass transition temperature of room temperature, that is, 25 ° C. or lower. .. If the glass transition temperature is higher than 25 ° C, it is not suitable as the rubber particles of the present invention.

<Transparent mapping>
The transmission mapping property according to the present invention is measured using a mapping property measuring device (for example, a mapping property measuring device ICM-1T manufactured by Suga Test Instruments Co., Ltd.). A parallel light beam is incident on the test piece of the acrylic resin film at an angle of 75 degrees, and the measurement is performed under the condition that the optical comb width is 0.125 mm. By moving the optical comb perpendicular to the optical axis of the transmitted light of the test piece, the amount of light (M) when the transmitted portion of the comb is on the optical axis and the amount of light (m) when there is a light-shielding portion of the comb are obtained. The ratio (C value (%)) of the difference between the two (M-m) and the sum (M + m) is a measure of image sharpness.
The C value is preferably 80% or more, and particularly preferably 90% or more.

[Acrylic resin film manufacturing equipment and manufacturing method]
A manufacturing apparatus that can be used for manufacturing the acrylic resin film according to the present invention will be described.
The apparatus for producing the acrylic resin film is not particularly limited, and a general film forming apparatus by a solution casting method can be used.

FIG. 1 is a schematic view of an apparatus used in a method for producing an acrylic resin film preferable to the present invention.

The acrylic resin is dissolved in an appropriate amount of organic solvent in the charging kettle 41 and sent to the filter 44 to remove large agglomerates and sent to the stock tank 42. After that, various additive liquids (for example, a plasticizer, a matting agent, an ultraviolet absorber, etc.) are added from the stock tank 42 to the main dope melting pot 1 to prepare the main dope.

As additives, plasticizers, matting agents, ultraviolet absorbers and the like are appropriately added to the charging kettle 41 after being stirred and diluted with a solvent in the additive charging kettle to obtain an additive liquid.

The main dope is spread from the die 30 onto the endless support 31, peeled off at the peeling position 33 to form a web, conveyed by a large number of rollers, and then stretched by the tenter device 34. The stretched web is transported while being dried by a large number of transport rollers 36 in the roller drying device 35, and is wound by the winding device 37.

Although not shown, it is preferable to appropriately provide a slit device for adjusting the film width and an embossing device for improving the film sticking failure by imparting unevenness to the end of the film during the process.

Further, Japanese Patent Application Laid-Open No. 2000-301555, Japanese Patent Application Laid-Open No. 2000-301558, Japanese Patent Application Laid-Open No. 7-032391, Japanese Patent Application Laid-Open No. 3-193316, Japanese Patent Application Laid-Open No. 5-086212, JP-A-62-037131 , JP-A-2-276607, JP-A-55-014201, JP-A-2-111511, JP-A-2-208650, etc. It can be applied to the invention.

The method for producing an acrylic resin film of the present invention comprises an acrylic resin having a glass transition temperature (Tg) in the range of 120 to 180 ° C. and a weight average molecular weight of 300,000 to 4 million, and a rubber having a core-shell structure. A step of producing a dope containing particles, a step of producing a dope obtained by filtering the dope using a filter having a filtration accuracy of 5 to 100 μm, and a step of casting the dope after filtration on a support to peel off the web. It has a step of drying the web and a step of drying the web.

Each process will be described in detail. Hereinafter, the "acrylic resin film" may be simply referred to as a "film".

(0) Raw Material Storage / Supply Process The manufacturing process of the acrylic resin film according to the present invention includes a process of storing the raw material in a package form to be distributed and supplied, a process of unpacking and storing it in a silo, a tank, or the like. Further, it is preferable to include a step of transferring to another silo, a tank, or the like.
The packaging form at the time of distribution and supply of raw materials is not particularly limited, such as paper bags, flexible container bags, containers, tank trucks, etc., but a packaging form that blocks temperature, humidity, ultraviolet rays, and oxygen during storage is particularly preferable.
Acrylic resin has a relatively low glass transition temperature compared to other resins, so it is prone to blocking. As for the storage environment conditions, low temperature, low humidity and low load are preferable. Therefore, it is not preferable to use a silo having an unnecessarily large capacity. In a low humidity environment, there is a concern of dust explosion, and it is preferable to ground the storage container / transfer pipe and, in some cases, replace it with an inert gas.
The raw material acrylic resin has fluctuations in weight average molecular weight due to lot variations during manufacturing (synthesis). In order to avoid fluctuations in the viscosity of the dope when switching lots, it is preferable to store a large number of lots in separate storage containers and blend the lots so that the weight average molecular weight is leveled. By storing separate lots in at least two silos and supplying them to the next step in a form in which the lot blend amount of one and the other has a gradation, it is possible to avoid a sudden change in the dope viscosity.
The raw material of the acrylic resin film according to the present invention also includes a self-returning material. It is preferable that the returned material be stored in the same state as other raw materials. It should be noted that the return material is usually a flake-shaped film fragment and is more likely to cause blocking.
The method of transferring the raw material is not particularly limited, such as transfer by free fall, air transfer in the pipe by air, transfer by a screw feeder or a vibration feeder. In order to avoid the concern of dust explosion, it is preferable to remove static electricity and ground to reduce triboelectric charge, increase the filling rate of the raw material in the pipe to reduce the oxygen concentration, or replace it with an inert gas. In particular, since the return material does not have good fluidity, a screw feeder capable of forced discharge is preferable.
The weighing at the time of transfer may be controlled by the rotation of the feeder, but the load cell method for measuring the weight of the receiving container is preferable.

(1) Dope preparation step (dissolution step)
In an organic solvent mainly a good solvent for the acrylic resin, the acrylic resin, in some cases, a plasticizer and various function-developing agents (for example, antioxidants, light stabilizers, ultraviolet absorbers, retardation adjusters) are used in the dissolution kettle. , Peeling accelerator, infrared absorber, matting agent, etc.) is dissolved while stirring to form a dope, or the acrylic resin solution is mixed with a solution of the plasticizer or various function-developing agents. This is a step of preparing a dope that is a solution.
In the present invention, a dope containing an acrylic resin having a glass transition temperature (Tg) in the range of 120 to 180 ° C. and a weight average molecular weight of 300,000 to 4,000,000 and rubber particles having a core-shell structure. It is characterized by preparing.

When the acrylic resin film according to the present invention is produced by the solution casting method, the organic solvent useful for preparing the dope can be used without limitation as long as it simultaneously dissolves the acrylic resin and other compounds.

For example, the chlorine-based organic solvent is dichloromethane, and the non-chlorine-based organic solvent is methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2 , 2,2-Trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2 -Methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane and the like can be mentioned. For example, dichloromethane, methyl acetate, ethyl acetate and acetone can be preferably used as the main solvent, and dichloromethane or ethyl acetate is particularly preferable.

In addition to the above organic solvent, the dope preferably contains a linear or branched aliphatic alcohol having 1 to 4 carbon atoms in the range of 1 to 40% by mass. Higher proportions of alcohol in the dope will gel the web, facilitating peeling from the metal endless support, and lower proportions of alcohol will result in cyclic polyolefins and other non-chlorine organic solvent systems. It also has a role in promoting the dissolution of the compound. In the film formation of the acrylic resin film according to the present invention, a dope having an alcohol concentration in the range of 0.5 to 15.0% by mass is used to form a film from the viewpoint of improving the flatness of the obtained acrylic resin film. The method can be applied.

In particular, a dope composition in which an acrylic resin and other compounds are dissolved in a solvent containing dichloromethane and a linear or branched aliphatic alcohol having 1 to 4 carbon atoms in a total range of 15 to 45% by mass. Is preferable.

Examples of the linear or branched aliphatic alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Methanol and ethanol are preferable because of the stability of these internal dopes, the relatively low boiling point, and the good drying property.

A method for dissolving an acrylic resin, a plasticizer, or a function-expressing agent under normal pressure, a method below the boiling point of the main solvent, a method under pressure above the boiling point of the main solvent, JP-A-9-95544, special publication. Various melting methods such as a method of performing by a cooling melting method as described in JP-A-9-95557 or JP-A-9-95538 and a method of performing at high pressure described in JP-A-11-21379 are used. However, a method of pressurizing at a temperature equal to or higher than the boiling point of the main solvent is particularly preferable.

Further, as the acrylic resin and the additive, it is preferable to use the mixing apparatus shown in FIG. 5 of JP-A-2011-143360. The mixing device is a liquid supply pipe for supplying a liquid to a mixing tank for mixing a liquid and a solid substance, and is one or more branch pipes into which the liquid is injected, and a branch pipe communicated with the branch pipe. It has one main pipe that supplies the liquid injected into the mixing tank, and in the projection view from the main pipe axial direction, the liquid movement direction in the branch pipe is the main pipe radial direction from the communication position with the branch pipe in the main pipe. The branch pipes are arranged so as to have an inclination angle between them. It is preferable to introduce from a solid matter introduction pipe having such a branch pipe from the viewpoint of reducing foreign matter.

Specifically, the solutions of the additives such as the plasticizer, the ultraviolet absorber, the matting agent, and the antioxidant are independently added, preferably from the solid matter introduction tube 5 shown in FIG. 5 of the above-mentioned publication, and are added as the main solvent. It is dissolved or dispersed in the dope to form a dope.

The type of the pressure container used for dissolving the acrylic resin is not particularly limited, as long as it can withstand a predetermined pressure and can be heated and stirred under pressure. In addition, instruments such as a pressure gauge and a thermometer are appropriately arranged in the pressure vessel. Pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. The heating is preferably performed from the outside, and for example, the jacket type is preferable because the temperature can be easily controlled.

The heating temperature at which the solvent is added is equal to or higher than the boiling point of the solvent used, and in the case of two or more mixed solvents, the temperature is such that the temperature is higher than the boiling point of the solvent having the lower boiling point and the solvent does not boil. Temperature is preferred. If the heating temperature is too high, the required pressure will be high and productivity will be poor. The preferred heating temperature range is 20 to 120 ° C, more preferably 30 to 100 ° C, still more preferably 40 to 80 ° C. The pressure is adjusted at the set temperature so that the solvent does not boil.
As for the order of transferring the raw materials to the melting pot and adding them, it is preferable to add the raw materials of the powder, particularly the acrylic resin, with a certain amount of organic solvent in the melting pot. In addition, if the entire amount of raw materials is added at once, the raw materials with a light specific density will gather near the liquid surface to generate stepchildren, and the melting time will be long. It is preferable to adjust the charging speed to 1 to 10% / min.
At the input port to which the powder is added, the powder may be welded to each other to form a lump due to contact with the vapor of the organic solvent. Therefore, it is preferable to vent so that the vapor of the organic solvent is guided to another place during the addition. It is also preferable to process the inner surface with Teflon (registered trademark) so that the solidified substance does not adhere to the inlet.
Further, when an organic solvent having a large specific gravity (for example, methylene chloride or the like) is used, the acrylic resin does not reach the lower part of the kettle due to the difference in specific gravity from the resin, and the organic solvent tends to be rich. In order to ensure the uniformity of the dope, it is preferable to design the melting pot so that there is no dead portion, or design the stirring so that convection also turns to the dead portion.

In the acrylic resin dope preparation device according to the present invention, it is preferable that the device has a storage tank, a heat exchanger and a circulation path, and the storage tank and the heat exchanger are connected via the circulation path. .. Connecting via a circulation path means that there is a circulation path between the storage tank and the heat exchanger, and there is a circulation path between the heat exchanger and the storage tank. The circulation path may be heat exchangeable, and the circulation path may also serve as a heat exchanger. The dope may be returned to the storage tank from the dope outlet of the storage tank via the heat exchanger, or may be returned to the storage tank via the heat exchanger from a port other than the dope outlet of the storage tank. Alternatively, two or more dope preparation devices provided with a circulation path may be connected. In this case, additional solvent may be added in the second storage tank. The circulation channel has the function of efficiently shortening the dissolution time and also has the ability of complete dissolution. In general, in a dissolution container provided with a circulatory system, it takes too much time to reach a dissolved state simply by circulating. On the other hand, in a heat exchanger in which heat is applied to a solution for a short time, gel is likely to be generated in the dope and the time is too short to completely dissolve the dope.

The storage tank used in the present invention is preferably a pressure-resistant container equipped with a jacket inside or outside the tank and having a stirrer having a shearing force as described below, in order to make the dope more uniform.
Further, a dry film formed by drying the dope is likely to be formed on the gas-liquid interface of the dope and the wall surface of the storage tank, and film failure due to the outflow of the dry film is often a problem. In order to prevent this, it is preferable to control the vapor pressure of the organic solvent in the storage tank to bring it into a saturated vapor pressure state. Specifically, it is preferable to introduce a device for spraying the organic solvent in the form of a mist into the storage tank and control the operation so as to operate sufficiently with respect to the saturated vapor pressure.

In the process of dissolving a mixture of acrylic resin and a solvent, it is preferable to stir over the shear force of 9.8~9.8 × 10 5 ^N. Stirring within the range of the shearing force allows the powder agglomerates to be crushed and dissolved shortly after the powder agglomerates are formed, and even if they are formed, the powder agglomerates can be crushed and dissolved. Poor weak dispersion efficiency stirring force at a shear force of less than 9.8 N, also too fine dispersion was more than 9.8 × 10 5 ^N, clogging occurs in a filtration step after significantly reduce the filtration efficiency I will let you. The shear force can be controlled by the rotation speed of the drive motor M.

After the acrylic resin is melted, it is taken out from the container while cooling, or it is taken out from the container with a pump or the like and cooled by a heat exchanger or the like, and the obtained polymer dope is applied to the film forming. The cooling temperature at this time. May be cooled to room temperature.

The concentration of the acrylic resin in the dope is preferably in the range of 10 to 40% by mass. After adding the compound to the dope during or after dissolution to dissolve and disperse it, it is filtered with a filter medium, defoamed, and sent to the next step with a liquid feed pump.

(Moisture content)
In the dope preparation step, the water content is 2.0 to 5.0% by mass during the start-up from the start of production to the steady operation, and the water content is 0.1 to 2.0% by mass during the steady operation. From the viewpoint of the stability of the dope and the transparency of the film, it is preferable to make such adjustments.

As a method of setting the water content at the time of startup within the range of 0.6 to 2.0% by mass with respect to the total amount of the dope, the water content in the dope is obtained from the total of the water content in the resin and the water content in the alcohol. There is a method of calculating the ratio, mixing the shortage with a solvent, and then preparing as a dope.

Since the line speed is slow at the time of startup, if the water content is less than 2.0% by mass with respect to the total amount of the dope, the web tends to be peeled off from the endless support before peeling. If the film is peeled off, it will have to be started up again, and productivity will deteriorate. Further, when the water content is larger than 5.0% by mass, the solubility of the acrylic resin in the solvent is deteriorated and the endless support is liable to be contaminated.

As a means for lowering the water content of the dope within the range of 0.6 to 2.0% by mass from the start-up to the steady operation, it is adjusted by adding the predetermined acrylic resin and other additives in-line. That, the water content in the dope is calculated from the total of the water content in the resin and the water content in the alcohol, and the adjusted low water content dope is gradually lowered by flowing it to the line. Can be mentioned.

The dope used in the present invention tends to have a high viscosity of 100,000 Pa · s as the molecular weight of acrylic increases. In order to feed the high-viscosity dope at a high flow rate, it is preferable that the diameter of the liquid feed tube is 100 mm or more and the withstand voltage is 20 kg or more. Further, it is preferable to select a liquid feed pump having a capacity corresponding to the above-mentioned high-viscosity dope. Further, it is also preferable to install a static mixer in the middle of the liquid feeding pipe in order to prevent the aggregation of fine particles and the gelation of the doping during the liquid feeding.

Further, when the fine particles are added to the acrylic resin dissolving step, the dissolution and mixing is preferably carried out at a temperature equal to or higher than the boiling point of the main solvent and not higher than the boiling point of + 50 ° C. As described above, by defining the temperature of the dissolution and mixing of the fine particles in the acrylic resin dissolution step to the boiling point of the main solvent + 50 ° C. or lower, the foreign matter generation rate can be surely suppressed in the dope dissolution and mixing step.

Further, it is preferable to dissolve and mix the fine particles in the acrylic resin dissolving step for a time in the range of 30 to 300 minutes. As described above, by defining the time for dissolving and mixing the fine particles in the acrylic resin dissolving step, the coefficient of variation (distribution) of the fine particles in the acrylic resin film does not deteriorate, and it is preferable from the viewpoint of production suitability such as foreign matter failure.

Further, it is preferable to add the fine particles to be added in the process of dissolving the acrylic resin during or after the addition of the acrylic resin to the dissolution kettle before the acrylic resin is completely dissolved in the dissolution kettle. In this way, by defining the timing of addition of the fine particles in the dissolving step of the acrylic resin, the foreign matter generation rate due to the addition of the fine particles contained in the acrylic resin solution (dope) can be surely determined in the dissolving and mixing step of the dope. It can be suppressed, the burden on the filter in the subsequent filtration process is greatly reduced, no foreign matter is generated, and the productivity is excellent.

In the method for producing an acrylic resin film of the present invention, a dispersion of fine particles is prepared in advance, this fine dispersion is added in a step of dissolving the acrylic resin in a main solvent, and after the addition, the temperature is equal to or higher than the boiling point of the main solvent. It is preferable to dissolve and mix.

As the solvent used when dispersing the fine particles, the organic solvent used when forming the film of the acrylic resin can be used. Alcohol is particularly preferable, and examples thereof include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol and the like having 1 to 8 carbon atoms.

The concentration of the fine particles when the fine particles are mixed with a solvent and dispersed is preferably 5 to 30% by mass, more preferably 8 to 25% by mass, and most preferably 10 to 15% by mass. The higher the concentration of fine particles in the fine particle dispersion, the lower the turbidity with respect to the amount added, and the better the haze and agglomerates, which is preferable.

The concentration of the fine particles when the solvent and a small amount of resin are mixed and dispersed is preferably 0.5 to 20% by mass, more preferably 1 to 5% by mass, and most preferably 1 to 3% by mass. The concentration of the resin is preferably 2 to 10% by mass, more preferably 3 to 7% by mass, and most preferably 4 to 6% by mass. This range is preferable because the dispersibility of the fine particles is excellent. The above range is preferable because a smaller content of fine particles has a lower viscosity and is easier to handle, and a higher content of fine particles has a smaller addition amount and is easier to add to the main dope.

As the disperser for dispersing the fine particles, a normal disperser can be used. Dispersers can be broadly divided into media dispersers and medialess dispersers. A medialess disperser is preferable for dispersing fine particles because of its low haze.

Examples of the media disperser include ball mills, sand mills, and dyno mills. Examples of the medialess disperser include an ultrasonic type, a centrifugal type, and a high pressure type, but in the present invention, a high pressure disperser is preferable. The high-pressure disperser is a device that creates special conditions such as high shear and high-pressure conditions by passing a composition in which fine particles and a solvent are mixed through a thin tube at high speed. By processing with a high-pressure disperser, for example, ^{it is preferable that the maximum pressure condition inside the device is 9.8 × 10 2} N or more in a thin tube having a tube diameter of 1 to 2000 μm. More preferably, it is 1.96 × 10 ³ N or more. At that time, those having a maximum reaching speed of 100 m / sec or more and those having a heat transfer speed of 100 kcal / hr or more are preferable.

Examples of the high-pressure disperser as described above include an ultra-high pressure homogenizer (2 trade names: microfluidizer) manufactured by Microfluidics Corporation, a nanomizer manufactured by Nanomizer, or Ultratarax, and other manton-golin type high-pressure dispersers such as Izumi. Examples thereof include a homogenizer manufactured by Food Machinery, manufactured by Sanwa Machinery Co., Ltd., and a product number UHN-01.
It is also preferable to install a dispersion blade that gives high shear in the dissolution kettle and disperse in the dope dissolution kettle so as to further control the dispersion state of the added dispersion liquid.

For example, the silica (Si) content in the fine particles contained in the acrylic resin film is determined by pretreating the absolutely dried acrylic resin film with a microdigest wet decomposition apparatus (sulfur nitrate decomposition) and alkali melting, and then ICP-AES. It can be obtained by performing analysis using (inductively coupled plasma emission spectrophotometer).

In the method for producing an acrylic resin film of the present invention, the same resin as the acrylic resin is dissolved and mixed in the fine particle dispersion added in the acrylic resin dissolving step, and the solid matter ratio of the fine particle dispersion is dissolved in the dissolving step. It is preferably 0.1 to 0.5 times the solid matter ratio of the acrylic resin solution (dope).

As described above, it is preferable that the fine particle dispersion liquid contains an acrylic resin in addition to the fine particles, so that the viscosity of the dispersion liquid is adjusted and the stagnation stability is excellent.

Further, in order to carry out co-infusion, as shown in FIG. 2 of JP-A-2009-072963, it is also preferable to use an apparatus capable of simultaneously preparing a plurality of types of dope preparations. In FIG. 2 of the publication, the raw material dope 11 is fed by the liquid feed pumps P3, P4, and P5 to the three dope flow paths 33, 34, and 35 for the intermediate layer, the support surface, and the air surface. .. Then, in the dope flow path 33 for the intermediate layer, after the additive liquid 13 stored in the stock tank 36 is added by the liquid feed pump P6, the raw material dope 11 and the additive liquid are added by the in-line mixer 39 and the shear mixer 43. 13 is mixed to form the dope 16 for the intermediate layer. Similarly, in the dope flow path 34 for the support surface, the raw material dope 11 and the additive liquid 14 are mixed by the in-line mixer 40 and the shear mixer 44 to generate the dope 17 for the support surface, and the dope flow path for the air surface is generated. In 35, the raw material dope 11 and the additive liquid 15 are mixed by the in-line mixer 41 and the shear mixer 45 to generate the dope 18 for the air surface. If necessary, a diluted solution for adjusting the TAC concentration of the dope may be added to the dope flow paths 34 and 35 for the support surface and the air surface.

By the above method, as shown in FIG. 2 of the above-mentioned publication, for example, three kinds of dope 16, 17, 18 having an acrylic resin concentration of 5 to 40% by mass can be produced. Then, the generated three types of dope 16, 17, and 18 are sent to the casting section through the filter.

(2) Filtering Step In the method for producing an acrylic resin film of the present invention, doping of a dope is an important step from the viewpoint of ensuring optical uniformity and reducing foreign matter failure.
The present invention is characterized in that the dope is prepared by filtering the dope using a filter having a filtration accuracy in the range of 5 to 100 μm.

In the present invention, filtration of the acrylic resin solution (dope) is preferable because the gel-like foreign matter in the dope can be removed by filtering the dope at a temperature equal to or higher than the boiling point at 1 atm of the main solvent. The preferred temperature range is 40 to 120 ° C, more preferably 45 to 70 ° C, and even more preferably 45 to 60 ° C. From the viewpoint of doping the dope, the method for producing an optical film of JP2012-56103A is also preferably used.

In the filter, the dope is filtered with a filter medium having, for example, a 90% collected particle size of 10 to 100 times the average particle size of the fine particles.

There are several methods of filtration, but filter presses and disc filters are suitable for filtering acrylic resin dope, and filter press type filtration is particularly productive in that it can take a large filtration area. Suitable from the point of view.
FIG. 2 shows an example of the filtration flow.
As shown in FIG. 2, the solution (dope) in which the acrylic resin is dissolved is temporarily stored in the stationary tank (stock tank) 103 from the dissolution kettle (not shown). A pump 105 and an on-off valve 113 are interposed in the middle of the dope flow-through pipe 104 from the static tank 103 to the main filtration device 100, and a solvent injection pipe from the diluting solvent tank 106 is located downstream of the on-off valve 113. 107 is connected. Further, an on-off valve 115 is interposed in the dope flow pipe 104 on the outlet side of the main filtration device 100.

When the main filtration device 100 is initially filled with the dope, the opening / closing valve 113 in the middle of the dope flow pipe 104 is opened, and the opening / closing valve 115 in the middle of the dope flow pipe 104 on the outlet side of the main filtration device 100 is closed. The opening / closing valve 114 of the solvent injection pipe 107 is opened to dilute the dope of acrylic resin having a viscosity of, for example, 10 to 50 Pa · s, which is sent from the static tank 103 into the flow pipe 104 by the operation of the pump 105. A solvent is injected from the solvent tank 106, and a dope having a predetermined high viscosity for casting is diluted with a solvent to reduce the viscosity to, for example, 1 to 9 Pa · s, and this low-viscosity dope is used as a main filtration device. By injecting into 100 and initial filling, air bubbles in the main filtration device 100 and the air bubbles inside the filter medium (not shown) are expelled. When the low-viscosity dope is injected into the main filtration device 100 in this way, the low-viscosity dope easily permeates the filter medium, spreads to every corner of the filter medium, and can expel air bubbles inside the filter medium.

At the initial stage of filling the main filtration device 100, it is preferable to open the opening / closing valve 114 of the solvent injection pipe 107 and continuously inject the solvent from the diluting solvent tank 106. Then, when the air in the main filtration device 100 and the air bubbles in the filter medium (not shown) are completely expelled, the opening / closing valve 114 of the solvent injection pipe 107 is closed.

After that, by opening the opening / closing valve 115 in the middle of the dope flow pipe 104 on the outlet side of the main filtration device 100, the main filtration device 100 provided with the filter medium in which the initial filling is completed and the bubbles are expelled is used, and the static tank is used. After passing through the main filtration device 100, a dope having a predetermined high viscosity for casting, which is sent from 103 to the inside of the casting pipe 104 by the operation of the pump 105, is supplied from the feeding pipe 104 to the casting die 110. , The dope is flowed from the flow pipe 104 onto the endless support 111 to perform flow-cast film formation.

In the present invention, the filter medium of the main filtration device 100 is preferably filter paper. By using this filter paper, only agglomerates such as fine particles that cause foreign matter can be removed, and the high-viscosity main dope can be continuously filtered. Film formation is possible and productivity is improved.

The filter of the present invention used for the main filtration device 100 needs to have a filtration accuracy in the range of 5 to 100 μm. Since the acrylic resin according to the present invention has a high molecular weight of 300,000 to 4,000,000, the dope has a high viscosity. If high-precision filtration of less than 5 μm is attempted for a high-viscosity dope, the filtration pressure rises and local aggregation or high-viscosity components are forced to pass through, resulting in unsatisfactory filtration. Casting with agglomerates or local high-viscosity components in the dope is not preferable because it results in non-uniformity of the cast film based on the local viscosity distribution. Of course, this is also not preferable because coarse foreign matter cannot be removed by low-precision filtration larger than 100 μm. It is presumed that by setting the filtration accuracy within an appropriate range, agglutination or high-viscosity components in the dope will be appropriately divided and dispersed, the local viscosity distribution will be eliminated, and a finely uniform film will be obtained. ..
The filtration accuracy in the present invention refers to the value of the minimum particle size that can collect 99.9% or more of the particle size distribution of the particles. That is, theoretically, a filtration accuracy of 5 μm means that 99.9% of monodisperse particles of 5 μm are collected, and for monodisperse particles of less than 5 μm, a collection rate of less than 99.9% and monodisperse particles larger than 5 μm are collected. The collection rate is greater than 99.9%. However, practically, it is a value having a certain width, and a filter of 4.5 μm is nominally called 5 μm in the actual measurement of filtration accuracy. In the present invention, the value rounded off in 1 μm units is adopted.
The filter in the present invention preferably has a multi-stage configuration. In that case, the filter that obtains the effect of the present invention refers to the filter having the highest accuracy (the lowest numerical value of filtration accuracy).

In the present invention, the drainage time of the filter medium of the main filtration device 100 is preferably 10 to 25 sec / 100 ml, more preferably 10 to 20 sec / 100 ml, and most preferably 12 to 17 sec / 100 ml. Here, if the drainage time of the filter medium is short, less than 10 sec / 100 ml, the strength of the filter paper such as the filter paper is weak, so that the filter paper opens due to the pressure, and foreign matter failure increases. Further, when the filtration time of the filter medium exceeds 25 sec / 100 ml, the initial pressure becomes high, the filtration resistance becomes too high, and high flow rate filtration cannot be continuously performed, and therefore, the filter life becomes short. Therefore, it is not preferable. The drainage time is measured in accordance with JIS P 3801, and a pressure of 0.98 kPa at 20 ° C. and 100 ml of distilled water ^{on a 10 cm 2 filtration surface using a Hertzberg filtration rate tester.} It refers to the time to be filtered by.

For the collection particle size and drainage time of the filter paper of the main filtration device 100, select the fiber material such as the fiber thickness and material (cotton linter, wood pulp, rayon, polyester fiber, etc.) of the filter paper, and use a beater to beat the fiber material. It can be arbitrarily adjusted depending on the method of manufacturing the filter paper, such as the degree of beating and the addition of a filler.

In the present invention, even one filter paper of the main filtration device 100 is effective, but it is more preferable to use 2 to 7 filter papers in a stack because the filtration efficiency is high. The same filter paper may be combined, or a filter paper having a small reserved particle size may be combined inside. Further, it is preferable to use a guard filter paper for removing large dust on the outside. The guard filter paper has a large collection particle size of 20 μm or more, and a soft cotton-like filter paper is preferable because it does not affect the filtration pressure and can remove large dust, and can also prevent liquid leakage from the main filtration device 100. In addition, two-stage filtration in which the main dope that has been filtered once is filtered once again is also preferable because it has a large effect of removing aggregates.

In the main filtration device 100, an acrylic resin film having less foam failure (foreign matter) can be obtained by filtering using a filter paper having a filtration time of 10 to 25 sec / 100 ml. In this case, the filtration pressure is achieved. Is preferably filtered at 16 kg / cm ² or less to form a film. More preferably, the filtration pressure is 12 kg / cm ² or less, and more preferably the filtration pressure is 10 kg / cm ² or less. The filtration pressure can be controlled by appropriately selecting the filtration flow rate and the filtration area.

Filtration filters used in the filtration process can be broadly classified into two types, surface type and depth type, according to their media structure. The surface type is a type in which the distance of the medium through which the object to be filtered passes is short, and the size of the particles that can be removed is determined by the opening of the surface. In the present invention, when the surface type filter is used for a long time, gel-like agglomerates come into contact with each other on the surface, grow into larger agglomerates, and pass through the filter due to an increase in pressure, so that the agglomerates cannot be removed and increase. There is a concern that it will make you.

Examples of the surface type include a filter paper pleated cartridge filter TC type manufactured by Advantech Toyo Co., Ltd. and a metal mesh used for a sieve.

On the other hand, the depth type filter is also called deep filtration or volumetric filtration, and has a certain thickness of media. This type of filter has a lower possibility of contact between aggregates at the filter part than the surface type, it is difficult to generate large gel-like aggregates, the pressure rise is small even after long-term use, and the gel It is preferable because the agglomerates can be removed.

Examples of the depth type include a wind cartridge filter TCW type manufactured by Advantech Toyo Co., Ltd., a depth cartridge filter TCPD type, and a fine pore NF series manufactured by Nippon Seisen Co., Ltd.

It is preferable that the additive liquid added in-line is filtered by at least two or more depth filters having different pore diameters because it can effectively filter various agglomerates of different sizes, and deterioration is deteriorated. Less preferred.

These filters are those having a particle collection rate of 5 to 10 μm of 20 to 60% when eight kinds of 0.5 ppm aqueous dispersions of test powder 1 specified in JIS Z 8901 are filtered. Preferably, the additive liquid is filtered through these filters and then added in-line. The particle collection rate is more preferably 30 to 50%. It is preferable that the particle collection rate is low so that the agglomeration does not grow, and that the particle collection rate is high is preferable in that the agglomeration is removed. Examples of the particle collection rate of 20 to 60% include wind cartridge filters TCW-1N, 3N, 5N, 10N, 25N, 50N, pleated cartridge filters TCPE-10, and 30 of Advantech Toyo Co., Ltd. Can be mentioned. Examples of the particle collection rate of 30 to 50% include wind cartridge filters TCW-3N, 5N, 10N, and 25N manufactured by Advantech Toyo Co., Ltd. Further, filtering a filter having a particle collection rate of 20 to 60% with a filter having a low particle collection rate and then further filtering with a filter having a high particle collection rate removes the agglomerates without growing the agglomerates. Is the most preferable. The particle collection rate is defined as follows.

(Particle collection rate)
A 0.5 ppm aqueous dispersion of 8 types of test powder 1 (material used in Kanto Loam) specified in JIS Z8901 was filtered at 10 liters / min, and the number of particles in the stock solution and filtrate was measured with an automatic particle counter. The particle collection rate of 5 to 10 μm was determined. The filter used at this time was filtered using one filter having a size of 250 mm × φ60. The number of filtrations was one.
Particle collection rate (%) = (number in undiluted solution-number in filtrate) / (number in undiluted solution) x 100
In order to obtain the acrylic resin film according to the present invention, the filter defined above is used as a filter for filtering the additive liquid added in-line to the main dope in the step of producing the acrylic resin film by the solution casting method, and then in-line. It is preferable to add it.

Also in this filter, a depth type filter is preferable for the above reason.

Filters are divided into membrane type and pincushion type according to the filter medium structure. The Membrane type is a type in which there are many holes with a certain size and distribution in the filter medium, and when several filter media with holes with the same size and distribution are stacked, it becomes a Membrane type surface type filter and the outside. A membrane type and depth type filter can be made by stacking several filter media with the size of the holes in the filter media gradually reduced toward the core to a certain thickness (10 to 20 mm).

Examples of the membrane type include a membrane cartridge filter TCF type manufactured by Advantech Toyo Co., Ltd., a pleated cartridge filter TCPE type, and the like.

The bobbin type uses endless long fibers such as polypropylene with a certain void in the filter medium without twisting, and is wound around the core at a certain density, and has a density gradient from the core that is the core. If it is wound without winding, it becomes a surface type, and if it is made finer toward the core, such as changing the voids of the filter medium or giving a density gradient, it becomes a depth type filter. As a thread winding type, for example, there is a wind cartridge filter TCW type manufactured by Advantech Toyo Co., Ltd. (a core is a hollow core around which a thread of a filter medium or a membrane is wound).

In the production of the acrylic resin film of the present invention, the main dope may be cast as it is, but various additives may be added in-line to the main dope, mixed and cast, depending on the purpose. Since the agglutination contained in the in-line additive liquid is in the form of a gel of secondary and tertiary agglutination, the agglutination (object) is easily removed by the membrane type filter medium, and the spool type is superior in the ability to capture the agglutination (object). preferable.

Also in this type of filter, a depth type filter is preferable for the above reason.

Further, polypropylene is preferable as the filter medium of the filter from the viewpoint of solvent resistance. Further, polypropylene or stainless steel is preferable as the core material of the filter, and stainless steel is more preferable. Stainless steel is preferable because the core does not easily swell due to the solvent even if it is used for a long time, and the agglomerates do not come off from the tightening part. Is preferable. The effect of removing agglomerates is improved when the filtration by these filters is performed a certain number of times. However, if it is too large, the effect will be small for the man-hours, so the number of times of filtration is preferably 3 to 10 times.

In the method for producing an acrylic resin film of the present invention, it is preferable to filter the main dope with a metal filter having an absolute filtration accuracy of 30 to 60 μm immediately before mixing the additive liquid with an in-line mixer (in the immediately preceding step). Immediately before means that there is a filtration process immediately before in terms of process, and in terms of flow, immediately after filtration, the additive liquid does not stagnate continuously, for example, a stock tank, a liquid feed pump, etc. It is sent to the in-line mixer without intervention and mixed with the main dope. As a result, it is preferable that the liquid does not stagnate and no new agglomerates are generated by the liquid feed pump. These filters are arranged immediately before the in-line mixer, and for example, large agglomerates generated from the path due to filter replacement etc. are surely removed from the additive liquid in the liquid feed by one filtration. As a filter for this purpose, a metal filter having the above-mentioned absolute filtration accuracy and having solvent resistance that can be used for a long period of time is preferable. As the metal, stainless steel is preferable from the viewpoint of durability. Further, unlike the depth type filters described above, these filters are preferably not replaced very frequently after installation, and therefore have a porosity of ε = 60 to 80% from the viewpoint of clogging. preferable.

Therefore, the most preferable for the in-line additive liquid is to filter with a metal filter having an absolute filtration accuracy of 30 to 60 μm and a porosity of ε = 60 to 80%, thereby ensuring long-term reliability. It is preferable because coarse foreign matter can be reliably removed. Metal filters with an absolute filtration accuracy of 30 to 60 μm and a porosity of ε = 60 to 80% include, for example, NF-10, NF-12, and NF- of Nippon Seisen Co., Ltd.'s Fine Pore NF series. 13 and the like can be mentioned.

The filter provided immediately before the in-line addition is preferably filtered by a metal filter having an absolute filtration accuracy of 30 to 60 μm, more preferably 40 to 50 μm. A smaller absolute filtration accuracy is preferable because it has an excellent ability to remove agglomerates, and a larger absolute filtration accuracy is preferable in that the increase in differential pressure is small even when used for a long time, the frequency of filter replacement can be reduced, and productivity is excellent.

(3) Casting step As shown in FIG. 1, the metal endless support 31, which is made of metal, feeds the dope to the pressure die 30 through a liquid feed pump (for example, a pressurized metering gear pump) and transfers the dope indefinitely. For example, it is a step of casting a dope from a pressure die slit to a casting position on an endless support such as a stainless steel belt or a rotating metal drum.

The dope is preferably fed to the die at 50 to 2000 L / hr in order to suppress the occurrence of film thickness deviation due to the flow rate fluctuation.

(Hypersalivation)
As a method of spreading the solution, a method of uniformly extruding the prepared dope from a pressure die onto a metal endless support, and a method of uniformly extruding the dope once cast on a metal endless support with a blade to increase the film thickness. There are a method using a doctor blade for adjusting, a method using a reverse roll coater for adjusting with a roll that rotates in the reverse direction, and the like, but a method using a pressure die is preferable. The pressure die includes a coat hanger type, a T die type, and the like, and any of them can be preferably used. In addition to the methods listed here, various methods for casting a film of a cellulose triacetate-based resin, which are conventionally known, can be carried out, and each condition should be set in consideration of the difference in the boiling point of the solvent used. Therefore, the same effect as that described in each publication can be obtained. As the endless metal endless support used for manufacturing the acrylic resin film according to the present invention, a drum whose surface is mirror-finished by chrome plating or a stainless belt (band) whose surface is mirror-finished by surface polishing. It may be said) is used.

In the metal endless support, the surface energy of the surface of the endless support in contact with both ends in the width direction of the dope flow film is in contact with the width center of the dope flow film. It is preferable to apply an activation treatment to the surface of the endless support so that the energy becomes higher than the surface energy of the endless support from the viewpoint of suppressing the fluttering of the ear portion.

The activation treatment is preferably performed by atmospheric pressure plasma irradiation or excimer UV irradiation, and the surface energy of the surface of the endless support in contact with both ends in the width direction of the casting film after the activation treatment is performed. Is γse, and when the surface energy of the surface of the endless support in contact with the central portion in the width direction of the casting film is γsc, the difference Δγ (= γse-γsc) is in the range of 0.1 to 60 mN / m. It is preferable to be in. Each from both ends in the width direction of the flow film in contact with the surface of the endless support having a surface energy higher than the surface energy of the surface of the endless support in contact with the center of the dope in the width direction. The width is preferably in the range of 0.05 to 0.25 Wr, where the width of the casting film is Wr.

The surface energy of the endless support can be measured by measuring the contact angles with water, nitromethane and methylene iodide, and using the Young Forks formula from these values. Specifically, it can be measured using a contact angle meter or the like manufactured by Kyowa Interface Science Co., Ltd.

Further, the endless support having a hydrophobic layer having a water contact angle of 90 ° or more formed in the casting film forming area on the endless support is used, and the casting film is formed on the hydrophobic layer. It is preferable to form it. The hydrophobic layer is composed of a hydrophobic substance, the endless support is composed of a cooling drum, and the cast film is peeled off with self-support by cooling gelation. Further, the hydrophobic substance is preferably PTFE or PP.

Further, in order to improve the releasability (peelability) of the film from the metal endless support and to produce an acrylic resin film having excellent transparency and flatness, iron is applied to the surface of the metal endless support. Metal endless support containing elements of (Fe) and / or chromium (Cr) and having a component element composition ratio on the surface of the metal endless support satisfying the following relationships (i) and / or (ii). It is preferable to use the body.

(I) (Fe ₂ O ₃ + FeO) / Fe = 5 to 50
(Ii) (CrO ₂ + CrO ₃ ) / Cr = 10 to 50
This creates a metal oxide film layer with a higher oxygen bond ratio than the oxide state of a normal metal surface while maintaining a very smooth surface state, so that even during continuous production of film, the metal It is possible to manufacture an acrylic resin film having improved releasability (peeling property) of the film from the endless support, very smooth peeling property, and excellent optical properties of transparency and flatness. can. Furthermore, it is possible to prevent corrosion of the surface of the metal endless support, and quality defects such as unevenness that appears when the corrosion pattern is transferred to the film are eliminated, and when the surface becomes rough due to corrosion, The anchor effect prevents the releasability (peeling property) of the web from being significantly deteriorated.

If the (Fe ₂ O ₃ + FeO) / Fe ratio of (i) is less than 5, the corrosion resistance is not much different from that of the untreated one, and the difference in treatment is partially large, which is the surface surface. It is not preferable because it becomes uneven due to the progress of corrosion. In addition, when the (Fe ₂ O ₃ + FeO) / Fe ratio exceeds 50, it becomes difficult to polish and restore a smooth surface when something comes into contact with the surface and causes scratches. Therefore, it is not preferable.

Further, if the (CrO ₂ + CrO ₃ ) / Cr ratio of (ii) is less than 10, the corrosion resistance is not much different from that of the untreated one, and the difference in treatment is partially large, which is the surface. It is not preferable because it becomes uneven due to the progress of corrosion. Further, when the (CrO ₂ + CrO ₃ ) / Cr ratio exceeds 50, it becomes difficult to polish and repair the surface to a smooth surface when something comes into contact with the surface and causes scratches. Therefore, it is not preferable.

Furthermore, even if the film forming speed is increased, the occurrence of air entrainment phenomenon is prevented, and the adhesion between the casting film and the endless support is appropriately adjusted, so that the spreading film can be peeled off from the endless support. When the dope is flowed onto the endless support, a liquid containing at least one organic compound contained in the dope is supplied between the endless support and the flow film to form a flow film. It is also preferable to form an intervening membrane between the endless support and the support.

As shown in FIG. 3, an intervening film forming apparatus 140 is provided in the vicinity of the casting die 130, and is interposed on the surface of the casting bead 161 which is a flow of the ribbon-shaped dope 160 from the casting die 130 on the endless support side. The film forming liquid 162 is supplied.

The intervening film forming apparatus 140 has a tank (not shown) for storing the intervening film forming liquid 162, a flow path 140a of the liquid, and a supply port 140b. At the time of casting the dope 160, an appropriate amount of the intervening film forming liquid 162 is supplied from the supply port 140b so as to be along the entire width region of the casting bead 161 on the endless support surface side. Thereby, even if the film forming speed is increased, the occurrence of the air entrainment phenomenon in the flow-through bead 161 can be further prevented. Then, when the spreading bead 161 and the intervening film forming liquid 162 reach on the spreading drum 150, the spreading film 170 is formed on the spreading drum 150 via the intervening film 163. As described above, the presence of the intervening film 163 between the casting drum 150 and the casting film 170 can prevent the occurrence of the air entrainment phenomenon.

The intervening film forming liquid 162 is a liquid containing at least one organic compound (solvent) contained in the dope 160, and is a mixture of the above-mentioned raw material solvent and a poor solvent which does not show compatibility with the polymer contained in the dope 160. It is preferable to prepare the above. The intervening film 163 formed between the casting drum 150 and the spreading film 170 by such an intervening film forming liquid 162 diffuses toward the spreading film 170 with the passage of time. As a result, the adhesion between the casting drum 150 and the casting film 170 does not become too high, so that the casting film 170 can be easily peeled off from the casting drum even with a small stripping stress.

Further, when the ratio of the solvent contained in the intervening film forming liquid 162 regardless of whether it is a good solvent or a poor solvent is w (%) and the film thickness of the intervening film 163 is t (μm), w and t are t. It is preferable to satisfy <-0.05w + 15. This makes it possible to form an intervening film 163 that acts to allow the flow film 170 to be easily stripped from the flow drum 150. However, if the intervening membrane 163 is too thick, diffusion between the accumulator film 170 and the intervening membrane 163 is unlikely to occur, and the intervening membrane 163 may remain on the accumulator drum 150. If the intervening film 163 remains on the casting drum 150 in this way, the subsequent casting is also adversely affected, and only a film having an inferior surface shape can be produced, which is unsuitable.

The installation location of the intervening film forming apparatus 140 is not limited to the form shown in FIG.

In order to increase the production speed of the film, foaming due to entrainment of accompanying air is eliminated, and the film thickness unevenness due to the vibration of the casting liquid film from the casting die due to the vacuum chamber suction wind is reduced, and the dropped scale is melted. In order to obtain a film with excellent flatness without transfer failure due to droplet scattering of excess liquid, dope is cast on a metal endless support, and a casting film (web) is cast on the endless support. ) Is provided with a downwardly open decompression chamber as a means of depressurizing from the upstream side of the flow so that the web is formed in close contact with the endless support, and when the dope is flowed down from the flow die. In order to prevent the formation of a whisker-like film (scale) on the left and right ends (casting die edges) corresponding to both ends in the film width direction of the casting die, a scale dissolving liquid is dropped under the scale dissolving droplets. It is preferable to provide means. The left and right sides of the decompression chamber having the main decompression chamber and the outside of the rear wall are provided with outer walls at predetermined intervals between these walls, and are located on the left and right sides of the decompression chamber and outside the rear. In addition, it is a preferred embodiment to form a sub-decompression chamber that opens downward and to increase the decompression force of the sub-decompression chamber in the range of -30 to −300 Pa, rather than the decompression force of the main decompression chamber.

Further, it is preferable that the gap between the left and right side walls and the rear wall of the decompression chamber having the main decompression chamber and the left and right outer walls and the rear outer wall of the sub decompression chamber facing them is 10 to 300 mm.

The wall surface other than the surface in contact with the casting die of the decompression chamber is duplicated to form a sub-decompression chamber, and the decompression force of the sub-decompression chamber on the outer side of the decompression chamber is larger than the decompression force of the main decompression chamber on the inner side of the decompression chamber. Then, by strongly sucking, the flow of suction air from the side surface to the casting liquid membrane is blocked in the discharge direction of the casting liquid membrane, and even if the production speed of the film is increased, the accompanying air In addition to eliminating foaming due to entrainment, the stability of the casting liquid film is improved even when the depressurization degree is increased due to the increase in the dope discharge rate due to high-speed film formation, and the casting liquid is also applied in the high-speed film formation region. It is possible to reduce film film unevenness in the film transport direction due to film vibration, and it is possible to produce a film with good smoothness.

In addition, the excess liquid content of the scale-dissolved liquid dropped on both ends of the web from the means under the scale-dissolved droplets at the casting die edge during film formation can be sucked and recovered toward the sub-decompression chamber. A film with excellent flatness can be obtained without transfer failure due to the scattered droplets of the excess liquid of the scale solution dropped by the scale solution, and the accumulation of endless support stains due to the scattered droplets of the excess liquid of the scale solution. It has the effect of being able to produce a thin and wide film that can be formed at high speed, with high production efficiency and excellent quality.

If the gap between the left and right side walls and the rear wall of the decompression chamber having the main decompression chamber and the left and right outer walls and the rear outer wall of the sub decompression chamber facing them is 10 to 300 mm, the decompression chamber is called a so-called decompression chamber. The decompression chamber is duplicated inside and outside, and the accompanying air is drawn relatively strongly from the sub-decompression chamber having a predetermined gap on the outer side of the decompression chamber with a decompression force larger than the decompression force of the main decompression chamber inside the decompression chamber. It is possible to reduce the suction air from the side surface to the end of the liquid film, realize stable casting, and support the excess liquid of the scale solution blown off from the casting die edges (both left and right ends). It can be collected in the sub-decompression chamber, which has a strong external suction force (decompression force), and has the effect of being able to stably produce high-quality films at a high production rate for a long period of time.

Further, it is preferable that the gas concentration in the vicinity of the flow dope of the decompression chamber is 80% or less.

This is because the concentration of gas (mainly vaporized volatile organic solvent) in the air near the casting bead increases, and when the gas component reaches the desired concentration, it may liquefy, and the liquefied solvent spreads. It may adhere to the bead and make the cast film defective. Further, when the pressure is reduced on the endless support contact surface (hereinafter referred to as the back surface of the flow bead) of the flow bead, the formation of the flow bead is stable, but in this case, the gas is easily liquefied. There may be a problem that the liquefaction solvent adheres to the cast film or adheres to the decompression chamber and causes non-uniformity of decompression. In such a case, there is a problem that the surface surface of the produced film is defective and optical unevenness occurs, or unevenness in the width direction of the film (hereinafter referred to as horizontal unevenness) occurs. It is improved by reducing the gas concentration to 80% or less as in the above.

That is, by setting the gas concentration to 80% or less, it is possible to prevent the gas component from being liquefied, and it is possible to prevent the gas component from being liquefied and causing a failure of adhering to the flowing bead. The film obtained by the above method suppresses the occurrence of optical unevenness and horizontal unevenness.

The degree of decompression of the decompression chamber is preferably in the range of -1500 to -200 Pa with respect to the atmospheric pressure. The doping rate of the dope is preferably in the range of 7 to 40 m / min.

Further, from the viewpoint of preventing liquefaction, it is also preferable to spray the solvent gas in the vicinity of the cast bead. The proportion of vapor contained in the solvent gas component is preferably in the range of 5 to 65% by volume, and the solvent is preferably dichloromethane. The solvent is a mixture containing the largest amount of dichloromethane and mixed with a compound that dissolves or disperses the polymer, and the proportion of dichloromethane gas contained in the vapor is preferably 80% by volume or more.
As a mechanism for spraying the solvent gas, the one described in JP2013-156488 is preferably used.

Further, it is also preferable to use a decompression chamber having a plurality of decompression chambers as the decompression chamber from the viewpoint that the accompanying wind can be suppressed from being applied to the flow bead and the thickness unevenness of the film can be suppressed.

For example, a decompression chamber having a plurality of decompression chambers for decompressing the contact surface side of the endless support of the casting bead is used, and the gap between the decompression chamber and the endless support is set to a range of 0.05 mm or more and 3 mm or less. Of the plurality of decompression chambers capable of independently adjusting the decompression degree, the decompression chamber on the upstream side in the moving direction of the endless support may be set to a lower decompression degree than the decompression chamber on the downstream side. preferable. The gap between the decompression chamber and the endless support is more preferably in the range of 0.05 to 0.7 mm, and most preferably in the range of 0.05 to 0.5 mm.

Further, when the maximum value of the absolute pressure of each decompression chamber is Pn (Pa), the pressure of each decompression chamber should be in the range of 0.9 × Pn (Pa) or more and 1 × Pn (Pa) or less. Is preferable, and more preferably, the adjustment is preferably made in the range of 0.98 × Pn (Pa) or more and 1 × Pn (Pa) or less. The number of the decompression chambers is preferably 2 or more and 10 or less, and it is preferable that each decompression chamber is provided with an exhaust port.

Further, it is preferable to blow the solvent gas onto the upper part of the casting die and send the solvent gas to the slit outlet while following the surface of the casting die.

It is preferable that the lower portion of the blower unit is provided with a nozzle having a slit-shaped blower port formed long in the width direction of the flow bead.

The blower unit is installed downstream of the endless support in the traveling direction with respect to the flow die and above the endless support. The lower part of the blower unit is provided with a nozzle having a slit-shaped air outlet formed long in the width direction of the flow bead, from the air port to the slit outlet, and in the entire width direction of the flow bead. A solvent gas containing the vapor of the solvent used for preparing the dope is sent toward the slit, and the concentration is maintained at a high concentration in the vicinity of the slit outlet as long as the solvent gas is not liquefied. In this embodiment, since dichloromethane is used as the solvent for preparing the dope, the solvent gas containing the vaporized dichloromethane is sent to the vicinity of the slit outlet.

The solvent gas shall contain vapor in a proportion in the range of 5 to 65% by volume. It is more preferably in the range of 20 to 65% by volume, and particularly preferably in the range of 40 to 65% by volume. In the air where the solvent gas concentration in the vicinity of the casting bead is maintained high as described above, the casting bead is prevented from drying. Therefore, the dope is solidified in the vicinity of the slit outlet to become a foreign substance, and the adhesion is suppressed, so that a film having an excellent surface shape without streak failure or the like can be manufactured.

In the solution casting method, if the flow rate of the solution is not precisely controlled, the end of the dope flowing down may be disturbed or burrs (surplus film at the end) may occur at the end of the slit, resulting in film formation speed and film thickness. There is a problem that it is difficult to apply it in a long-term stable state over a wide range.

In the present invention, in the method of producing a film by the solution casting method, when the dope is cast on a metal endless support by a casting die, the solvent is allowed to flow down to both ends of the slits of the casting die, and the solvent is applied. The inner diameter of the tips of the nozzles on both sides of the flowing die is 4 mm or less and 0.5 mm or more, and the solvation parameter (-△ HD-BF3) of the flowing solvent is 15 [kJ / mol] or more and 100 [kJ / mol] or more. ] The following is preferable.

Here, the solvation parameter is P.I. C. Maria, J.M. F. Gal, J Phys. Chem. , 89, 1296 (1985), and P. et al. C. Maria, J.M. F. Gal, J.M. de Franceschi, E.I. Fargin, J.M. Am. Chem. Soc. , 109, 483 (1987), the standard molar enthalpy [kJ / mol] (−ΔHD-BF3) in the 1: 1 complex formation of gaseous BF3 and donor molecule in the dichloromethane solvent.

It is preferable that the solvent flowing down the nozzles on both sides of the casting die is, for example, methyl acetate. That is, according to the method for producing an acrylic resin film of the present invention, when a solvent having a large solvation parameter is used, the solubility in the acrylic resin becomes small, but the generation of swelling can be suppressed. Although this factor is not clear, it can be inferred that such a phenomenon may occur because the swelling and dissolution states of the acrylic resin differ depending on the value of the solvation parameter.

Further, in the method for producing an acrylic resin film of the present invention, the surface of the metal endless support is irradiated with atmospheric pressure plasma or Exima ultraviolet rays before the dope or the resin melt is cast on the metal endless support. Surface treatment is preferable.

In this case, the integrated time of the atmospheric pressure plasma irradiation treatment or the excimer ultraviolet irradiation treatment is preferably 0.1 to 3000 sec, preferably 0.5 to 500 sec.

Here, if the cumulative time of the atmospheric pressure plasma irradiation treatment or the excimer ultraviolet irradiation treatment is less than 0.1 sec, the surface is not sufficiently modified and the corrosion resistance of the surface is not improved, which is not preferable. Further, if the cumulative time of the atmospheric pressure plasma irradiation treatment or the excimer ultraviolet irradiation treatment exceeds 3000 sec, the surface becomes rough and rough, which is not preferable.

According to the present invention, a high-energy irradiation device (A) consisting of a normal pressure plasma device and an oxygen ultraviolet device is used to perform high-energy surface treatment, and the surface of a metal endless support rather than a surface oxide film naturally formed in the atmosphere. It is preferable to form a metal oxide film layer having an increased oxygen bond ratio.

The pressure die used in the method for producing an acrylic resin film of the present invention may be one or more installed above a metal endless support. It is preferably one or two. When two or more units are installed, the amount of dope to be cast may be divided into various ratios for each die, or the dope may be sent from a plurality of precision metering gear pumps to the dies at each ratio. The temperature of the acrylic resin solution used for casting is preferably −10 to 55 ° C, more preferably 25 to 50 ° C. In that case, all of the processes may be the same, or different parts of the process may be different. If they are different, the desired temperature may be used immediately before the casting.

The width of the cast can be in the range of 1 to 4 m, preferably in the range of 1.5 to 3 m, more preferably in the range of 2 to 2.8 m. The surface temperature of the metal endless support in the casting step is set in the range of −50 ° C. to a temperature at which the solvent does not boil and foam, more preferably -30 to 100 ° C. A higher temperature is preferable because the drying speed of the web can be increased, but if it is too high, the web may foam or the flatness may deteriorate. The preferred endless support temperature is appropriately determined in the range of 0 to 100 ° C, and more preferably in the range of 5 to 30 ° C. Alternatively, it is also a preferable method to gel the web by cooling and peel it off from the drum in a state containing a large amount of residual solvent. The method of controlling the temperature of the metal endless support is not particularly limited, but there are a method of blowing hot air or cold air and a method of bringing hot water into contact with the back side of the metal endless support. It is preferable to use hot water because the heat transfer is more efficient and the time until the temperature of the metal endless support becomes constant is short. When using warm air, in consideration of the temperature drop of the web due to the latent heat of vaporization of the solvent, hot air above the boiling point of the solvent may be used, and air at a temperature higher than the target temperature may be used while preventing foaming. .. In particular, it is preferable to change the temperature of the endless support and the temperature of the drying air between casting and peeling to efficiently perform drying.

As the casting die, a pressure die is preferable because the slit shape of the base portion of the die can be adjusted and the film thickness can be easily made uniform. Pressurized dies include coat hanger dies, T dies, etc., and even if two or more pressure dies are provided on a metal endless support in order to increase the film forming speed, the dope amount is divided and laminated. good.

An end failure called Kawabari may occur when the solution is poured, and the cause of this failure is a minute defect at the tip of the die. These die defects include minute scratches and dents that occur during die manufacturing and maintenance, and scratches that occur during grinding with a grindstone.

Therefore, we proceeded with further studies to develop a means to prevent the occurrence of swelling due to the minute defects at the tip of the die. In the method of producing an acrylic resin film by pouring it from a slot of a solution die dissolved in a solution, if the hardness Hv at the tip of the die is set to 400 or more, minute scratches on the die during production, maintenance, and installation, It was found that the dents were suppressed and the streak defects in the flow direction were improved until it became difficult to confirm. The hardness expressed by Hv (Vickers hardness) is a value obtained by reading the diagonal length of the indentation generated by using a diamond pyramid having an apex angle of 136 ° as an indenter and dividing the load by the surface area of the recess. ..

Further, in the method of producing an acrylic resin film by casting a solution in which a resin is dissolved in a solvent from a die slot, the surface tension of the tip of the die is set to 380 μN / cm or more to prevent the occurrence of kawabari. Furthermore, it was found that the streak defect was improved. The surface tension is based on JIS K6768, manufactured by Wako Pure Chemical Industries, Ltd., Wetting Index Standard Solution, No. From 32 to No. It is a value measured using 54.

Further, in order to prevent the occurrence of kawabari, the unevenness of the surface of the lip tip portion and the corner portion between the slot surface and the tip flat end surface intersecting the slot surface are formed into a substantially arcuate cross section to form a curved surface, and the curvature thereof is formed. It was found that it is necessary to have a small radius of curvature of the surface and good solvent wettability, it was possible to prevent swelling at the tip of the lip, and it was possible to improve streak defects.

The corner of the lip tip of the slot, the corner surface of the slot surface and the flat end surface intersecting the slot surface, is formed into a substantially arcuate cross section to form a curved surface, and the radius of curvature R of this curved surface is 5 to 50 μm. It is preferable to set it in the range of.

The parallelism between the boundary line between the curved surface, the slot surface and the flat end surface of the tip, and the line connecting the center of curvature of the curved surface is in the range of 1.5 to 15 μm per 1 m in the longitudinal direction of the slot. It is preferable to do so. Further, the parallelism between the boundary line between the curved surface, the slot surface and the flat end surface of the tip, and the line connecting the center of curvature of the curved surface is set to 0 of the radius of curvature R around 1 m in the longitudinal direction of the slot. It is preferable to make it 3 times or less. Further, the parallelism between the boundary line between the curved surface, the slot surface and the flat end surface of the tip, and the line connecting the center of curvature of the curved surface is in the range of 0.5 to 5 μm per 1 mm in the longitudinal direction of the slot. Is preferable. Further, the parallelism of the boundary line between the curved surface, the slot surface, and the flat end surface of the tip and the line connecting the center of curvature of the curved surface is set to 0 of the radius of curvature R per 1 mm in the longitudinal direction of the slot. . It is preferable to make it 1 times or less.

When the surface roughness of the tip of the die is Ra, it is preferable that the surface roughness Ra in the longitudinal direction of the slot and the direction orthogonal to the longitudinal direction thereof is in the range of 0.01 to 3 μm.

If the surface temperature of the rotating roller is high after the dope is poured from the die onto the metal endless support, the effect of promoting gelation of the casting film cannot be sufficiently obtained. In addition, since the dew point at the stripped portion is high, dew condensation may occur on the surface of the cast film at the stripped portion, and even if the dewed moisture is dried and volatilized in a later process, fogging will occur on the film surface. There's a problem.

In order to improve this problem, in the solution casting method used in the present invention, in the rotating roller of the metal endless support, the first rotating roller having a surface temperature of -30 ° C or more and 6 ° C or less is used. The cast film directed to the second rotating roller is dried by a dry air, the cast film is conveyed from the second rotating roller onto the first rotating roller, and then peeled off at the peeling position where the dew point is 0 ° C. or lower. , The casting film on the belt toward the first rotating roller is cooled by the first rotating roller and the cooling means provided upstream of the peeling position, and the cooling section up to the peeling position is adjusted at the position of the cooling means. Thereby, it is preferable that the temperature of the cast film to be peeled off is less than 6 ° C., and the cooling roller as the cooling means is brought into contact with the belt surface opposite to the belt surface on which the cast film is formed. It is preferable to cool the casting film on the belt from the second rotating roller to the first rotating roller.

Further, it is preferable to adjust the temperature inside the casting chamber accommodating the first rotating roller and the second rotating roller so that the dew point at the peeling position is 0 ° C. or less. In that case, it is preferable that the solvent content in the dry amount standard at the peeling position of the casting film is in the range of 10 to 200% by mass. That is, since the dew point near the peeling position of the cast film is set to 0 ° C. or lower, dew condensation is prevented and moisture is suppressed from adhering to the cast film. As a result, fogging does not occur on the surface of the produced film.

Further, it is also preferable to provide roughened bands at both ends of the surface of the metal endless support from the viewpoint of easy peeling. It is preferable that both the roughened zones overlap with the flow width of the dope from the die by 5 to 30 mm, and the average roughness Rz of the roughened zones is in the range of 0.5 to 2 μm.

Generally, in the case of an endless support having a completely smooth surface, when the web is peeled off, both ends are easily torn and easily torn, so that production is often interrupted due to a fracture accident. On the other hand, by providing the roughened zone, the peelability is greatly improved, no film is generated, no bubbles are generated, and it is very effective. The width is the width from 5 to 30 mm inside the dope film to both ends of the endless support to the outside so that the position of the casting may be slightly displaced in the width direction. When the average roughness Rz of the roughened zone is smaller than 0.5 μm, there is no effect of roughening, the adhesion is too strong and it is difficult to peel off, and when it is larger than 2 μm, the roughened surface is caused. It becomes easy to adhere and difficult to peel off. The preferred range of Rz is 0.8 to 1.5 μm.

In recent years, there has been a demand for higher production speeds and thinner films, but in order to increase the speed, the temperature of the hot air blown to the cast film on the endless support must be raised. The temperature of the side edge of the rolled film rises, making it easier to foam, and as the thinning progresses, it becomes more susceptible to the temperature of the endless support, so there is a problem that the conventional method is insufficient as a countermeasure against foaming. ..

Therefore, a windshield member is provided so as to partition the flow film on the endless support into the central area and the side edge area in the width direction, and hot air is blown to the center area in the width direction of the flow film. It is preferable to make the temperature distribution uniform. Cold air may be blown from the inside to the outside of the flow film on the endless support in the width direction to make the temperature distribution in the width of the flow film uniform.

It is also preferable to blow cold air from the inside to the outside of the flow film on the endless support to make the temperature distribution of the flow film uniform in the width direction.

The windshield member may be provided parallel to the side edge in a range of 20 to 100 mm, more preferably 20 to 80 mm from the side edge of the flow film to the central portion side. Further, the gap between the windshield member and the flow film may be in the range of 5 to 30 mm, more preferably in the range of 5 to 15 mm.

Specifically, the cold air is blown by a blower duct, and the blower port of the blower duct is provided parallel to the side edge within a range of 20 to 100 mm from the side edge of the flow-casting membrane to the central portion side, and the blower port and the blower port are provided. It is advisable to set the gap between the duct and the cast film in the range of 5 to 30 mm, and blow the cold air so as to have an intersection angle in the range of 45 to 90 °, more preferably 60 to 80 ° with respect to the duct film. Further, the cold air has a dew point of -2 ° C. or lower and a temperature in the range of 15 to 60 ° C., and it is preferable to blow the cold air in a wind speed range of 1 to 10 m / sec.

It is also preferable to perform so-called initial drying, in which the surface of the cast film immediately after being formed on the endless support is dried using a drying device. As described above, the initial drying can effectively promote the evaporation of the solvent from the cast film.

However, in the initial drying, when the drying temperature exceeds the boiling point of the solvent contained in the casting film on the endless support, foaming due to the solvent occurs inside the casting film. In particular, in the vicinity of both end portions of the flow film, heat is easily transferred from the endless support to the flow film, so that foaming is likely to occur. When foaming occurs inside the casting film in this way, the surface of the casting film becomes uneven or voids are formed inside the casting film. Further, when a dry air adjusted to a predetermined temperature is sent out for drying, the dry air causes diagonal unevenness and uneven film thickness (thickness unevenness) on the surface of the cast film. Therefore, when such diagonal unevenness, thickness unevenness (generally referred to as unevenness unevenness), or the above-mentioned foaming occurs on the surface of the cast film, the flatness of the cast film is significantly deteriorated. Therefore, only a film having inferior flatness can be produced from such a cast film.

Therefore, the temperature (° C.) is within the range of 30 to 160 ° C. from the first air outlet which is provided so as to face the metal endless support and whose longitudinal direction is the width direction of the metal endless support. The first drying step of feeding the dry air, which has been made substantially constant, to the casting film immediately after formation while adjusting the static pressure (Pa) so as to be substantially constant within the range of 50 to 200 Pa, and the above-mentioned first. After one drying step, from the second air outlet provided so as to face the traveling direction of the endless support, with respect to the traveling direction of the endless support according to the residual solvent amount of the casting film. It is preferable to carry out a casting film drying method including a second drying step of sending out substantially parallel drying air.

Further, it is preferable to provide a partition member inside the first air outlet and divide the endless support into at least three areas with respect to the direction parallel to the traveling direction. An air volume control member is provided in a section of the first air outlet section located above the vicinity of both end portions of the flow film, and the air volume of the dry air to be sent out is adjusted in the width direction of the endless support. Is preferable.

While the residual solvent amount of the casting film is up to 250% by mass, it is preferable to perform the first drying treatment, and the temperature (° C.) is substantially constant within the range of 30 to 160 ° C. from the second air outlet. Therefore, the dry air adjusted so that the wind speed (m / sec) is substantially constant within the range of 5 to 20 m / sec can be sent out so as to be parallel to the traveling direction of the endless support. preferable.

In addition, due to the recent increase in quality demands, unevenness with irregularities having a periodic structure tends to become a problem. The following can be mentioned as means for preventing unevenness of unevenness having this periodic structure.
In the method for producing an acrylic resin film of the present invention, when the dope is poured from the die onto the support, it is preferable to keep the dope in an infinitely calm state immediately after the casting.
If it is not windless and the wind flow is non-uniform, the initial drying of the dope will be disturbed according to the non-uniformity, and the drying rate will vary locally, causing the dope to flow and the film thickness. Uniformity may be compromised.
Further, assuming that a uniform wind is blown, the surface of the convection film on the air layer side is rapidly cooled by the latent heat of evaporation, and a temperature gradient is formed in the direction of the layer of the convection film with the temperature-controlled contact surface on the belt side. So-called Benard convection occurs depending on the environment. Therefore, the film thickness uniformity may be impaired due to the difference in drying speed in a regular pattern on the film surface. For film thickness uniformity, it is preferable to dry the cast film in a windless state without air flow until the fluidity of the cast film becomes small. Specifically, it is preferable to set the environment at a wind speed of 0.2 m / s or less until the organic solvent in the cast film becomes 100% or less with respect to the dry solid content.
In order to create this windless environment, it is important to shield the area immediately after the flow from the outside to block the flow of wind, but it is necessary to convey the belt that is the support, and the volatile organic solvent. It is necessary to discharge, and it is impossible to construct a completely sealed system. Therefore, it is preferable to precisely calculate the pressure difference with the adjacent area and the shape of the opening between them, and design the wind speed in the vicinity of the flow film surface to be within the above range.

To improve the peelability of the cast film from the metal endless support, place a cooler in a specific temperature range on the surface of the moving endless support that is in contact during peeling and opposite the dope film peeling side. By contacting and controlling the amount of residual solvent at the time of peeling within a specific range, the peelability is improved and the peelability can be satisfactorily peeled from the endless support. That is, in the region where the amount of residual solvent at the time of stripping the cast film is controlled to 100% by mass or less and the cast film is stripped from the endless support, what is the flow film peeling side of the endless support? It is preferable to bring a cooling body having a surface temperature of 10 ° C. or lower into contact with the opposite surface.

The amount of the residual solvent is preferably controlled to 55% or less, and the surface temperature of the cooling body is preferably −5 ° C. or lower.

It is preferable that the cooling body also serves as a roller capable of rotating the moving endless support. As a method for controlling the surface temperature of the cooling body, for example, the surface temperature by cooling with a brachiler using an antifreeze solution is 10 ° C. or lower (the upper limit is preferably 5 ° C. or lower, more preferably 0 ° C. or lower, particularly. It can be preferably −5 ° C. or lower). The surface temperature of the cooling body is preferably 25 to 5 ° C, more preferably 25 to 0 ° C, and particularly preferably -20 to 0 ° C.

Further, it is also preferable to set the temperature of the entire metal endless support to -50 to 10 ° C., and the cooling rate from when the acrylic resin resin solution is poured onto the metal endless support until it is peeled off. Is expressed in terms of (temperature difference / hour), it is preferably 3 to 5 (° C./sec).

At that time, it is preferable to adjust the ratio of the poor solvent in the dope to the range of 2 to 20% by mass from the viewpoint of peelability.

It is preferable that a plurality of acrylic resin dope supply ports are provided at the upper end of the casting die, and the dope is supplied to the casting die from the plurality of supply ports into the manifold of the casting die.

(Hypersalivation)
When performing laminated casting such as co-flowing, narrowing the lip clearance of the casting die increases the shear of the discharge part, and the locally high concentration (high viscosity) part of the dope that causes stick slip is mixed. , It is possible to suppress the occurrence of circular deformation. In addition, when forming a multi-layer film, the stick slip itself becomes weaker and circular by lowering the viscosity of the dope that forms the outer layer (surface layer, air surface layer and / or back surface layer, endless support surface layer). Deformation does not occur. Further, there is a predetermined correlation between the lip clearance and the dope viscosity for forming the outer layer.

In a solution casting method in which a plurality of dopes containing a polymer and a solvent are co-sprayed from a casting die to form a multilayer film, the multilayer film at the temperature T1 (° C.) at which the dope is cast. The relationship between the dope viscosity V (Pa · s) forming the front surface or the back surface and the average value C1 (mm) of the lip clearance of the casting die is
V ≦ -146 × C1 + 219 is satisfied, and more preferably V ≦ −135 × C1 + 200.
More preferably, V ≦ -118 × C1 + 175.

The dope viscosity V (Pa · s) forming the front surface or the back surface of the multilayer film at the temperature T1 (° C.) when the dope is cast is preferably in the range of 5 to 60 Pa · s, more preferably. It is in the range of 5 to 55 Pa · s, and most preferably in the range of 7 to 40 Pa · s. The average value C1 (mm) of the lip clearance is preferably in the range of 0.9 to 1.5 mm, more preferably in the range of 0.9 to 1.2 mm, and most preferably in the range of 0.9 to 1.2 mm. The range is 9 to 1.1 mm. The temperature T1 (° C.) of the dope when casting the dope is preferably in the range of 20 to 38 ° C.

Further, at least two or more of the dope for the base layer, the dope for the endless support surface layer, and the dope for the air surface layer have different viscosities, and the thickness t1 (μm) of the base layer constituting the cast film and the endless support surface layer. The relationship between the thickness t2 (μm) and the thickness t3 (μm) of the air surface layer is preferably t2 ≦ t3 ≦ t1. Further, the ratio of t3 to the thickness of the cast film is preferably 3% or more and 40% or less.

The relationship between the viscosity η1 (Pa · s) of the dope for the base layer, the viscosity η2 (Pa · s) of the dope for the endless support surface layer, and the viscosity η3 (Pa · s) of the dope for the air surface layer is η3 ≦ η2. It is preferable that ≦ η1.

It is preferable that the mass A of the dope for the air surface layer and the mass B of the organic solvent contained in the dope satisfy 16 ≦ {(AB) / A} × 100 ≦ 21.

The raw material dope is preferably stirred and mixed with an in-line mixer after the additive is added. It is preferable to have a mouth.

It is preferable that the length L parallel to the radial direction of the pipe is 20% or more and 80% or less of the inner diameter of the pipe.

The gap between the slits is preferably 0.1 mm or more and 1/10 mm or less of the inner diameter of the pipe, and the distance D from the addition port to the in-line mixer is preferably 1 mm or more and 250 mm or less. Further, it is preferable that the flow rate V1 of the additive flowing in the pipe and the flow rate V2 of the raw material dope satisfy 1 ≦ V1 / V2 ≦ 5.

(Dry)
Drying of the dope on the endless support for the production of acrylic resin films is generally the surface side of the metal endless support (eg, drum or band), i.e. the surface of the web on the metal endless support. A method of applying hot air from the back surface of a drum or band, a method of applying hot air from the back surface of a drum or band, a temperature-controlled liquid is brought into contact with the band or the back surface opposite to the dope flow surface of the drum, and the drum or band is heated by heat transfer. There is a liquid heat transfer method for controlling the front surface temperature, but the back surface liquid heat transfer method is preferable. Alternatively, the IR heater described later is also preferably used. The surface temperature of the metal endless support before casting may be any number of times as long as it is below the boiling point of the solvent used for doping. However, in order to promote drying and to lose fluidity on the metal endless support, the temperature should be 1 to 10 ° C lower than the boiling point of the lowest boiling point solvent used. It is preferable to set it. This does not apply when the flow dope is cooled and peeled off without drying.

(Peeling)
This is a step of peeling off the web in which the solvent has evaporated on the metal endless support at the peeling position. The peeled web is sent to the next process as a film.

The temperature at the peeling position on the metal endless support is preferably in the range of 10 to 40 ° C, more preferably in the range of 10 to 30 ° C.

The amount of residual solvent at the time of peeling of the web on the metal endless support at the time of peeling is in the range of 10 to 130% by mass depending on the strength of the drying conditions, the length of the metal endless support, and the like. It is preferable to peel off in the range of 10 to 100% by mass, but when peeling off at a time when the residual solvent amount is larger, if the web is too soft, the flatness at the time of peeling is impaired, and slippage and vertical streaks occur due to the peeling tension. Because it is easy to do, the amount of residual solvent at the time of peeling is determined by the balance between economic speed and quality.

The amount of residual solvent in the web is defined by the following formula (Z).

Equation (Z)
Residual solvent amount (%) = (mass before heat treatment of web-mass after heat treatment of web) / (mass after heat treatment of web) × 100
The heat treatment for measuring the amount of residual solvent means that the heat treatment is performed at 115 ° C. for 1 hour.

The peeling tension when peeling the metal endless support and the film is usually in the range of 50 to 245 N / m, but if wrinkles are likely to occur during peeling, the peeling tension is 190 N / m or less. It is preferable to do so.

In the present invention, the temperature at the peeling position on the metal endless support is preferably in the range of −50 to 40 ° C, more preferably in the range of 5 to 40 ° C, and in the range of 5 to 30 ° C. Most preferably inside.

When a dry film is peeled off from a metal endless support, if the peeling resistance (peeling load) is large, the film is irregularly stretched in the film forming direction, causing optical anisotropic unevenness. In particular, when the peeling load is large, the portions that are stretched in a stepped manner in the film forming direction and the portions that are not stretched alternately occur, and a distribution is generated in the retardation. When loaded into a liquid crystal display device, unevenness becomes visible in a linear or strip shape. In order not to cause such a problem, it is preferable that the film peeling load is 2.5 N or less per 1 cm of film peeling width. The peeling load is more preferably 2 N / cm or less, further preferably 1.8 N or less, and particularly preferably 1.5 N or less. Even in a liquid crystal display device in which unevenness is likely to appear when the peeling load is 2.5 N / cm or less, unevenness caused by peeling is not observed at all, which is particularly preferable. As a method of reducing the peeling load, there are a method of adding a peeling agent as described above and a method of selecting the solvent composition to be used.

The peeling load is measured as follows. The dope is dropped onto a metal plate of the same material and surface roughness as the metal endless support of the film forming apparatus, spread to an even thickness using a doctor blade, and dried. Make a cut of equal width in the film with a cutter knife, peel off the tip of the film by hand, sandwich it with a clip connected to the strain gauge, and measure the load change while pulling up the strain gauge in the diagonal 45 degree direction. The volatile content in the peeled film is also measured. The same measurement is performed several times with different drying times, and the peeling load at the same time as the residual volatile matter at the time of peeling in the actual film forming process is determined. As the peeling speed increases, the peeling load tends to increase, and it is preferable to measure at a peeling speed close to the actual one.
As a means for reducing the peeling load, a peeling accelerator described later can also be preferably used.

The preferable residual volatile content concentration at the time of peeling is 5 to 60% by mass. However, although it depends on the acrylic resin used, if the residual volatile content concentration is 30% by mass or more, the film strength is poor and the film loses the peeling force and is cut or stretched. In addition, the self-retaining power after peeling is poor, and deformation, wrinkles, and knicks are likely to occur. It also causes a distribution in the retardation. On the other hand, peeling with a high volatile content has the advantage that the drying speed can be increased and the productivity is improved, which is preferable. Therefore, the residual volatile content concentration at the time of peeling is more preferably 10 to 55% by mass. It is particularly preferable that the release resistance is relatively small even if the amount of the release agent used is small, which is 15 to 50% by mass.

It is preferable that the stripping speed is 10 m / min or more and the fluctuation amount of the stripping position at 2 Hz or higher is less than 20 mm. When a stripping roller that supports the film immediately after stripping from the endless support is used, the distance L between the peeling position and the contact position of the film of the stripping roller is 0.1 mm to 100 mm. It is preferably in the range. It is preferable to adjust the temperature of the endless support in the range of 10 to 40 ° C.

At that time, the film forming speed is preferably in the range of 10 to 150 m / min. The temperature at the time of peeling is preferably in the range of 5 to 50 ° C.
The surface energy of the stripping roller is preferably in the range of 10 to 35 mN / m, more preferably in the range of 18 to 26 mN / m. In order to achieve such a range, the surface treatment of the stripping roller may be a treatment of hypercoat, cloamole, tungsten carbide, amucoat or the like, but ultrachrome II treatment is particularly preferable.

Further, the film immediately after being peeled off from the endless support is a thin soft film, and in the roller transport and the tenter transport step of holding and transporting both end portions (hereinafter referred to as ear ends) of the film, the film thickness is thinned. If the so-called thinning is performed, there arises a problem that stable transportation becomes difficult. Further, if the thickness of the ear end portion of the film is made too thick, peeling residue or the like may occur in high-speed film formation.

Therefore, even if the film is made thinner, it is preferable to increase the thickness of only the ear end of the film by a method other than lip clearance adjustment in order to ensure transport stability. A dope flow path for thickness correction at each ear end is provided, and the flow rate of the dope passing through the flow path is controlled by an adjustment mechanism different from the clearance adjustment at the tip of the die lip, and the dope for thickness correction is applied to both ears of the die. A method of supplying to the end portion and controlling the thickness of only the end portions of both ears of the film independently is preferable.

As a manufacturing apparatus that can be specifically used, in a film manufacturing apparatus that spreads a dope onto an endless support from a die body having a dope flow path, the film is placed on the die separately from the dope flow path. A flow path for correcting the thickness of both ends is provided, and the thickness of both ends of the film can be controlled independently. It is preferable that the device is provided with an adjustment mechanism for adjusting the flow rate of the correction dope passing through the correction flow path, and can independently control the thickness of both ends of the film. It is preferable that the correction flow path has an air bleeding portion. It is preferable that the correction flow path has a heat insulating mechanism that can be controlled independently of the die body, and the correction flow path outlet is a die lip from a flow path having a flow width of the die body. It is preferable that it is provided between the tip and the tip.

According to the method for manufacturing the film, both ends of the flow film become thicker, the strength of the film as a whole increases, and when the thin cast film is peeled off from the endless support, the peeling residue etc. The occurrence of abnormalities can be suppressed. In this method of thickening only both ends of the cast film, the die is provided with a flow path for correcting the thickness of both ends of the film, in addition to the flow path for doping provided in the main body of the die. Since the correction dope is supplied from the correction flow path and the thickness of both ends of the film is independently controlled, the present invention can be carried out with only a slight improvement in the conventional equipment. , Cost can be reduced. Further, by controlling the flow rate of the correction dope passing through the correction flow path by using a device equipped with an adjustment mechanism different from the clearance adjustment at the tip of the die lip, the film thickness can be controlled more accurately. It can be carried out.

(Atmosphere in the hypersalivation process)
In the casting step according to the present invention, the oxygen concentration in the casting step is preferably at least 10 vol%, more preferably less than 8 vol%. Further, when the drying step following the casting step is arranged in the same casing as the casting step, the oxygen concentration is less than 10 vol% even in the drying step, but the casting step and the drying step If there is no air permeability between the and, the oxygen concentration may be less than 10 vol% only in the casting process.

By setting the oxygen concentration to less than 10 vol% in this way, it is possible to prevent the explosion of the organic solvent gas and the like, and it is particularly effective when the concentration of the organic solvent gas in the casting process is high. That is, it is particularly effective when the concentration of the organic solvent gas is 25% or more of the lower explosive limit.

In order to reduce the oxygen concentration in the casting process to less than 10 vol%, an inert gas such as nitrogen gas or carbon dioxide gas or a mixed gas obtained by mixing the inert gas with air and having an oxygen concentration of less than 10 vol% is used. It can be done by supplying. It is preferable to measure the oxygen concentration in the casting process with an oxygen concentration meter and control the supply amount of the inert gas or the like according to the measured value.

(4) Drying / stretching step (4-1. Drying step)
The drying step can be divided into a preliminary drying step and a main drying step.

In order to dry the web obtained by peeling from the metal endless support, the web may be dried while being conveyed by a large number of rollers arranged vertically, or both ends of the web may be dried like a tenter dryer. May be dried while being transported by fixing with a clip.

The means for drying the web is not particularly limited, and generally, hot air, infrared rays, heating rollers, microwaves, or the like can be used, but hot air is preferable from the viewpoint of convenience.

An IR heater is mentioned as a suitable drying method using infrared rays. The IR heater will be described below.
Hot air drying is most preferable as the drying means in the present invention, but it is also preferable to use an infrared heater (IR heater) as an auxiliary.
Irradiation of a wet film containing infrared rays from an IR heater activates the movement of the solvent molecules that have absorbed the infrared rays, and can promote the movement in the film. Mid-infrared to far-infrared rays, which correspond to the stretching motion of solvent molecules, are particularly preferable. Further, it is more preferable that the resin other than the solvent does not have absorption in this irradiation wavelength band.
In addition, when the solvent molecules volatilize, the wet film is absorbed by the IR heater faster and more efficiently than the heat conduction of hot air drying, as opposed to the phenomenon of depriving the wet film of energy as latent heat of vaporization and lowering the temperature of the film. I think I can do it. This effect is more exerted in the first half drying with a large amount of solvent than in the second half drying with a small amount of solvent. Therefore, it is preferable to apply it between belt drying, peeling, and initial drying.
IR heaters are provided by NGK Insulators, Ltd., Hibeck Co., Ltd., Kashima Co., Ltd., etc. The irradiation type can be appropriately selected from line focusing, parallel irradiation and the like. It is preferable to adjust the irradiation time, output energy, number of heaters, etc. as appropriate before use.
It is preferable that the high temperature part of the IR heater and the volatile solvent are separated from each other. That is, it is preferable that the filament portion of the IR heater, which has a high local temperature, is protected by a transparent cooling system. Therefore, it is preferable to cover it with a double tube made of quartz glass and to cool it by flowing water through the glass gap. This makes it possible to block heat without blocking infrared rays emitted from the filament.
The present inventors have found that the curl of the optical film obtained by irradiation with an IR heater is suppressed. Although this mechanism is not clear, it is presumed that evaporation by infrared absorption will make the movement of solvent molecules in the film more uniform than evaporation by heat transfer, and the difference in physical properties between the front and back surfaces of the film will be smaller. There is. This effect is particularly exhibited by heating with an IR heater before introducing a tenter that heats at Tg or more.
Due to the occurrence of curl, the stress applied to the entire width of the film during roll transfer becomes non-uniform, and there has been a problem that scratches and wrinkles are formed on the film.
In addition to the above effects, it was also found that the film thickness deviation at the center of the film was improved by irradiating the IR heater only at the edges of the film before introducing the tenter. Although this mechanism is being elucidated, it is assumed that the viscoelasticity of the film in the tenter clip has changed in some way and the stress distribution to the center of the film during stretching has changed.

The drying temperature in the web drying step is preferably lower than the glass transition temperature of the film, and it is effective to perform the heat treatment at a temperature of 100 ° C. or higher within a range of 10 to 60 minutes. The drying temperature is in the range of 100 to 200 ° C., more preferably in the range of 110 to 160 ° C.

(4-2. Stretching step)
The acrylic resin film according to the present invention can be stretched to control the orientation of molecules in the film, and can improve flatness and obtain toughness. Further, the phase difference can be adjusted to a desired value.

The stretching operation may be carried out in multiple stages. Further, when biaxial stretching is performed, simultaneous biaxial stretching may be performed, or biaxial stretching may be performed step by step. In this case, the term “stepwise” means, for example, that stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any of the steps. Is also possible.

That is, for example, the following stretching step is also possible:
・ Stretching in the spreading direction → Stretching in the width direction → Stretching in the spreading direction → Stretching in the casting direction ・ Stretching in the width direction → Stretching in the width direction → Stretching in the spreading direction → Stretching in the spreading direction Simultaneous biaxial stretching includes the case of stretching in one direction and contracting the other by relaxing the tension.

The amount of residual solvent at the start of stretching is preferably in the range of 2 to 10% by mass.

When the amount of the residual solvent is 2% by mass or more, the film thickness deviation is small, which is preferable from the viewpoint of flatness, and when it is 10% by mass or less, the unevenness of the surface is reduced and the flatness is improved, which is preferable.

After peeling the web from the metal endless support, in the process of drying the web (film), the web is generally dried by a roll drying method (a method in which a large number of rolls arranged vertically are alternately passed through the web to dry) or a tenter method. The method of drying while transporting the film is adopted, and finally, the film is dried until the residual solvent amount is 0.5% by mass or less.

Further, the amount of residual solvent contained in the web may be a slightly higher amount in order to obtain a desired retardation value, and 15 to 100% by mass, preferably 20 to 100% by mass, in order to impart a high retardation value. It may have in the range of 50% by mass.

One of the methods for producing an acrylic resin film according to the present invention includes a stretching step of stretching in a direction perpendicular to the transport direction of the film (TD direction), and a heat treatment step downstream of the stretching step in the heat treatment step. The film temperature is set to a glass transition temperature (Tg) of -50 ° C or higher and Tg + 40 ° C or lower, the roll span of the guide roll in the heat treatment step is set in the range of 50 to 300 mm, and the transport tension of the film is set to 15 to 100 N / m. Heat treatment is performed as a range. Here, the glass transition temperature (Tg) refers to the glass transition temperature of the finished film.

According to the method for producing an acrylic resin film of the present invention, in the solution casting method, the glass transition temperature (Tg) to the film is suppressed while suppressing the shrinkage of the film in the width direction in another step downstream from the stretching step. By applying the above temperature, shrinkage in the MD direction (film transport direction) of the film, which could not be achieved by the cellulose ester resin produced by the conventional solution film forming method, is promoted, and retardation in the thickness direction (thickness direction retardation) Not only the reduction of Rt) but also the uniformity of the retardation value in the width direction can be ensured, and the haze value of the film can be reduced.

In the production method of the present invention, the stretching ratio in stretching in the film transport direction (MD stretching) is preferably 1 to 25%, more preferably 3 to 20%.

The "stretching ratio (%)" referred to here means what is obtained by the following formula.

Stretching ratio (%) = 100 × {(length after stretching)-(length before stretching)} / length before stretching The method of stretching the web in the film transport direction is not particularly limited. For example, a method of making a peripheral speed difference between multiple rolls and stretching in the vertical direction using the roll peripheral speed difference between them, fixing both ends of the web with clips or pins, and widening the distance between the clips and pins in the traveling direction. A method of stretching in the vertical direction, a method of spreading in the vertical and horizontal directions at the same time, and a method of stretching in both the vertical and horizontal directions can be mentioned. Of course, these methods may be used in combination. Further, in the case of the so-called tenter method, it is preferable to drive the clip portion by the linear drive method because smooth stretching can be performed and the risk of breakage can be reduced. The stretching in the vertical direction uses a device having two nip rolls, and by making the rotation speed of the nip roll on the outlet side faster than the rotation speed of the nip roll on the inlet side, the annular polyolefin film in the transport direction (longitudinal direction). Is preferably stretched. By performing such stretching, the expression of retardation can also be adjusted.

Similarly, the method for producing an acrylic resin film of the present invention includes a stretching step of stretching in a direction perpendicular to the transport direction of the film (TD direction), a heat treatment step upstream of the stretching step, and a film in the heat treatment step. The temperature should be a glass transition temperature (Tg) of -50 ° C or higher and Tg + 20 ° C or lower, the roll span of the guide roll in the heat treatment step should be in the range of 50 to 300 mm, and the transport tension of the film should be in the range of 15 to 100 N / m. It is preferable that the film is heat-treated, and the film is once cooled to a temperature equal to or lower than the glass transition temperature (Tg) on the downstream side of this heat treatment step, and then stretched. According to this method for producing an acrylic resin film, in the solution casting film forming method, the temperature is raised to a temperature near the glass transition temperature (Tg) in the process on the upstream side of the stretching step, and then the temperature is raised to a temperature near the glass transition temperature (Tg), and then the cooling step is performed again. By stretching while raising the temperature to a temperature near the glass transition temperature (Tg) again, an appropriate combination of in-plane retardation (Ro) and thickness direction retardation (Rt) can be realized, and the film can be formed. It is also possible to reduce the haze value of.

When the acrylic resin film according to the present invention is used as a retardation film for a VA type liquid crystal display, for example, the in-plane retardation (Ro) is in the range of 45 to 65 nm and the thickness direction retardation (Rt) is. It is in the range of 105 to 140 nm, and the ratio of the retardation in the thickness direction (Rt) to the in-plane retardation (Ro): Rt / Ro is preferably 1.6 to 2.6.

According to such an acrylic resin film according to the present invention, not only the thickness direction retardation (Rt) is lowered, but also the uniformity of the retardation value in the width direction can be ensured, and the in-plane retardation can be ensured. An appropriate combination of (Ro) and the retardation in the thickness direction (Rt) can be realized, and by reducing the haze value of the film, the front contrast of the liquid crystal display panel can be improved.

An example of a stretching step (also referred to as a tenter step) for producing a retardation film will be described with reference to FIG.

FIG. 4 schematically shows an example of a tenter stretching device 201 preferably used in producing an acrylic resin film according to the present invention. In the figure, the tenter stretching device 201 is schematically described, but usually, a large number of clips provided in a single row state of a pair of left and right rotary drive devices (ring-shaped chains) 201a and 201b composed of endless chains. Of the 202a and 202b, the left and right chains 201a, so that the clips 202a and 202b of the linear transition portion on the outward side of the chain that grip and pull the left and right ends of the film (F) are gradually separated in the width direction of the film (F). The track of 201b is installed so that the film F is stretched in the width direction.

In FIG. 4, in step A, the web (film) F that has been peeled off from the endless support (not shown) and conveyed is gripped by the left and right gripping means (clips) 202a and 202b, and in the next step B. The web is stretched in the width direction (direction orthogonal to the traveling direction of the web) at a stretching angle as shown in the figure, and in step C, the stretching is completed and the web is conveyed while being gripped. D is a step of relaxing the web in the width direction.

It is preferable to provide a slitter for cutting off the end portion in the width direction of the web after peeling the web from the endless support and before the start of step B and / or immediately after step C. In particular, it is preferable to provide a slitter that cuts off the end of the web immediately before the start of step A. When the same stretching is performed in the width direction, especially when comparing the case where the web end is excised before the start of step B and the condition where the web end is not excised, the former has a more optical slow axis distribution (orientation angle). The effect of improving the distribution) can be obtained.

In the tenter step, it is also preferable to intentionally create compartments having different temperatures in order to improve the orientation angle distribution. It is also preferable to provide a neutral zone so that the respective compartments do not interfere with each other between different temperature compartments.

The stretching operation may be performed in multiple stages, and it is preferable to carry out biaxial stretching in the casting direction and the width direction. Further, when biaxial stretching is performed, simultaneous biaxial stretching may be performed, or biaxial stretching may be performed step by step. In this case, the term “stepwise” means, for example, that stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any of the steps. Is also possible.

It is particularly preferable to transport the web peeled off from the metal endless support while drying it, and further to stretch it in the width direction by a tenter method in which both ends of the web are gripped with pins or clips, thereby causing a predetermined phase difference. Can be granted. At this time, stretching may be performed only in the width direction, or simultaneous biaxial stretching is also preferable. The preferred draw ratio is preferably 1.05 to 2 times, preferably 1.15 to 1.5 times. It may be shrunk in the longitudinal direction during simultaneous biaxial stretching, or it may be shrunk to 0.8 to 0.99, preferably 0.9 to 0.99. Preferably, the area is 1.12 to 1.6 times, preferably 1.15 to 1.5 times, due to lateral stretching and vertical stretching or shrinkage. This can be obtained by multiplying the stretching ratio in the vertical direction by the stretching ratio in the horizontal direction.

Further, the "stretching direction" in the present invention is usually used to mean a direction in which stretching stress is directly applied when performing a stretching operation, but when it is biaxially stretched in multiple stages, it is final. In addition, it may be used to mean the one with a larger draw ratio (that is, the direction usually becoming the slow axis).

The preheating time in step A is preferably a long time or a higher temperature. From the viewpoint of film temperature uniformity in the width direction and retardation controllability, 130 to 200 ° C. is preferable, and 3 to 60 seconds is preferable.

The web heating rate in step B is preferably in the range of 0.5 to 10 ° C./sec in order to improve the orientation angle distribution.

The stretching time in step B is preferably short. However, from the viewpoint of web uniformity, the minimum required stretching time range is specified. Specifically, it is preferably in the range of 1 to 10 seconds, and more preferably in the range of 4 to 10 seconds.

In the tenter step, the heat transfer coefficient may be constant or may be changed. As the heat transfer coefficient, it is preferable to have a heat transfer coefficient in the range of ^{41.9 to 419 × 10 3} J / m ^{2 hr.} More preferably, in the range of ^{41.9~209.5 × 10 3 J / m 2} hr, and most preferably a range of ^{41.9~126 × 10 3 J / m 2} hr.

The stretching speed in the width direction in the step B may be constant or may be changed. The stretching speed is preferably 50 to 2000% / min, more preferably 100 to 1000% / min, and most preferably 150 to 800% / min.

It is preferable to control the stress at the first 10 cm in the above step B in order to obtain the effect of the present invention, and it is preferable to control the stress in the range of 100 to 200 N / mm.

In the tenter process, it is preferable that the temperature distribution in the width direction of the atmosphere is small, from the viewpoint of improving the uniformity of the web, and the temperature distribution in the width direction in the tenter process is preferably within ± 5 ° C, preferably within ± 2 ° C. Is more preferable, and within ± 1 ° C. is most preferable. By reducing the temperature distribution, it can be expected that the temperature distribution on the width of the web will also be reduced.

In step D, relaxation in the width direction is preferable. Specifically, it is preferable to adjust the web width so as to be in the range of 95 to 99.5% with respect to the final web width after stretching in the previous step.

Further, in the present invention, in order to accurately orient the polymer, it is also preferable to use a tenter that can independently control the gripping length of the web (distance from the start of gripping to the end of gripping) by the left and right gripping means of the tenter.

Specifically, for example, FIG. 5 shows as a means for controlling the length of the portion gripping the left and right ends of the web independently by the tenter stretching device so that the gripping length of the web differs between the left and right sides. There is something like.

FIG. 5 schematically shows an example of a tenter stretching device 201 preferably used in manufacturing a retardation film.

In the figure, the installation positions of the clip starters 203a and 203b at the gripping start positions of the left and right gripping means (clips) 202a and 202b of the tenter stretching device 201 are the same on the left and right, and the installation positions of the left and right clip closers 204a and 204b are changed on the left and right. As a result, the left and right gripping lengths (Xa) and (Xb) of the film F are changed, whereby a force that twists the film F in the tenter stretching device 201 is generated, and the misalignment due to transportation other than the tenter stretching device 201 is corrected. Even if the transport distance from peeling to the tenter is lengthened, it is possible to effectively prevent the occurrence of meandering, wrinkles, and wrinkles on the web.

Further, in the present invention, in order to correct wrinkles, sagging, distortion and the like more accurately, it is preferable to add a device for preventing meandering of a long film, and the edge position controller described in JP-A-6-8663 (Japanese Patent Laid-Open No. 6-8663). It is preferable to use a meandering correction device such as an EPC) or a center position controller (sometimes referred to as a CPC). These devices detect the film ear edge with an air servo sensor or optical sensor and control the film transport direction based on that information, and the film transport direction is fixed at the center of the film ear edge and width direction. As its actuator, specifically, one or two guide rolls or a driven flat expander roll can be shaken left and right (or up and down) with respect to the line direction to correct the meandering or to correct the film. A pair of small pinch rolls are installed on the left and right (one on the front and one on the back of the film, which are on both sides of the film), and the film is pinched and pulled to correct the meandering. (Cross guider method). The principle of meandering correction of these devices is that when the film is running, for example, when trying to go to the left, the former method tilts the roll so that the film goes to the right, and the latter method is 1 on the right side. A set of pinch rolls is niped and pulled to the right. It is preferable to install at least one of these meandering prevention devices between the film peeling point and the tenter stretching device.

In addition, when stretching using a tenter stretching device, there are the following problems.
(1) Since stress is concentrated on the gripped portion of the film, breakage is likely to occur.
(2) Precipitates such as volatile additives adhere to the surface of the film, causing quality defects.
(3) At the outlet of the tenter, the film of the grip portion is greatly deformed, and slits (ear cutting) cannot be made.
In order to solve this problem, it is preferable to adjust the temperature of the gripping tool to be equal to or higher than the boiling point of the organic solvent and lower than the stretching temperature in advance to grip the cast film.
If the temperature of the gripper when gripping the web is lower than the boiling point of the organic solvent used, the organic solvent in the grip portion dries slowly, becomes softer than the central portion of the web, and breaks more frequently. Further, additives and the like in the web may be deposited on the grip portion, resulting in breakage or quality defects. Further, when the temperature of the gripping tool is higher than the stretching temperature, the gripping portion is in contact with the web, so that the heat transfer rate is faster than that of the central portion of the web, so that the web temperature of the gripping portion is higher than that of the central portion of the web. , The frequency of breakage increases. A more preferable range of the gripping tool temperature is 10 ° C. higher than the boiling point of the organic solvent used and 10 ° C. lower than the stretching temperature.

The method for adjusting the temperature of the gripping tool to a predetermined temperature range is not particularly limited, but it is preferable to provide a heating / cooling means on the return side of the gripping portion. For example, a method of directly blowing temperature-controlled hot air or cold air onto the grip portion, a method of passing the grip portion through the temperature-controlled zone, and the like can be preferably used. It is preferable to keep the temperature of the gripping tool at a temperature higher than the temperature at which additives and the like in the web do not precipitate on the return side of the gripping portion.

In the present invention, a method in which the transverse stretching is performed in two steps and the second step stretching is performed at a temperature 1 to 50 ° C. higher than the stretching temperature of the first step is also preferably used. There is no particular limitation on the method of increasing the stretching temperature. For example, in the case of hot air heating, a method of stretching the first stage stretching and the second stage stretching in two ovens controlled at different temperatures, radiation from a far infrared ray or a microwave heater, etc. In the case of heating, a method of performing the first-stage stretching and the second-stage stretching by changing the number of heaters and the capacity is preferably used. The first step and the second step may be continuously stretched, or after the first step of stretching, after passing through a cooling step, a width holding step, a longitudinal or width relaxation step, and the like, the stretching is performed. The second step of stretching may be performed. A method of setting the temperature in the oven to a higher level in a stepwise manner toward the downstream by the tenter method and stretching the oven is preferable because the equipment can be made compact.

After the treatment in the tenter step, it is preferable to further provide a post-drying step.

The means for drying the web in this step is not particularly limited, and generally, hot air, infrared rays, a heating roll, microwaves, or the like can be used, but hot air is preferable from the viewpoint of convenience.
It is preferable that the temperature of the web does not become too high when the web is dried while being transported. When the web is transported by applying tension in the transport direction, if the temperature of the web becomes higher than the softening temperature, wrinkles are generated on the web and a failure occurs. As a guideline for the drying temperature (the temperature of the web at the time of drying), a low temperature range of 10 to 50 ° C. is preferable with respect to Tg at the end of drying of the web. Further, since the softening temperature rises as the drying progresses, it is also preferable to raise the drying temperature accordingly. For example, the drying temperature is gradually increased to 30 to 50 ° C lower than Tg in the early stage of drying, 20 to 40 ° C lower than Tg in the middle stage of drying, and 10 to 20 ° C lower than Tg in the final stage of drying. Is preferably performed.
It is preferable to appropriately adjust the transport tension in order to suppress the occurrence of wrinkles due to transport. In particular, in the case of a thin film having a thickness of 10 to 20 μm, the tension is preferably 20 to 200 N per 1 m of film width, and more preferably 10 to 50 N.

(Diagonal stretching)
Diagonal stretching is a step of stretching a formed long film in a diagonal direction with respect to the width direction. In the method for producing a long film, the film can be produced to any desired length by continuously producing the film. In addition, as a method for producing a long stretched film, after forming a long film, the long film may be wound around a winding core once to form a wound body (also referred to as a roll) and then supplied to a diagonal stretching step. , The film may be continuously supplied from the film forming step to the diagonal stretching step without winding up the film after the film forming. It is preferable to continuously perform the film forming step and the diagonal stretching step because the film forming conditions can be changed by feeding back the results of the film thickness and the optical value after stretching, and a desired long stretched film can be obtained.

In the method for producing a long stretched film by diagonal stretching, a long stretched film having a slow phase axis at an angle of more than 0 ° and less than 90 ° with respect to the width direction of the film is manufactured. Here, the angle with respect to the width direction of the film is an angle in the film surface. Since the slow-phase axis in the film surface is usually expressed in the stretching direction or the direction perpendicular to the stretching direction, such stretching is performed at an angle of more than 0 ° and less than 90 ° with respect to the stretching direction of the film. A long stretched film having a slow axis can be produced.

The angle formed by the width direction of the long stretched film and the slow axis, that is, the orientation angle can be arbitrarily set to a desired angle within a range of more than 0 ° and less than 90 °.

A diagonal stretching device is used to impart diagonal orientation to the long film. In the diagonal stretching device used in the present embodiment, the orientation angle of the film can be freely set by variously changing the path pattern of the gripping tool traveling support, and further, the orientation axis of the film is extended in the film width direction. It is preferable that the film stretching apparatus can orient the film evenly on the left and right sides with high accuracy and can control the film thickness and retardation with high accuracy.

FIG. 7 is a schematic view for explaining diagonal stretching used in the method for producing a long stretched film of the present embodiment. However, this is an example, and the present invention is not limited thereto.

The traveling direction (traveling direction before stretching) D1 of the long film when feeding into the stretching device is different from the traveling direction (traveling direction after stretching) D2 of the long stretched film when feeding out from the stretching device. The feeding angle θi is formed. The feeding angle θi can be arbitrarily set to a desired angle in the range of more than 0 ° and less than 90 °.

The long film has left and right gripping tools (a pair of gripping tools) at both ends of the entrance of the diagonal stretching device (the gripping tool is the gripping start point for gripping the long film, and the straight line connecting the gripping start points is indicated by reference numeral A). It is gripped by the gripping tool pair) and travels as the gripping tool travels.

The gripping tool pair consists of left and right gripping tools Ci and gripping tools Co that face each other in a direction substantially perpendicular to the traveling direction (traveling direction before stretching) D1 of the long film at the entrance of the diagonal stretching device. The left and right gripping tools Ci and gripping tool Co each travel on a left-right asymmetrical path, and the position at the end of stretching (the gripping release point at which the gripping tool releases the grip, and the straight line connecting the grip release points is referred to as a reference symbol. Release the long stretched film gripped in (indicated by B).

At this time, the left and right gripping tools Ci and gripping tools Co facing each other at the entrance of the diagonal stretching device (position A in the figure) travel on the inner gripping tool running support tool Ri and the outer gripping tool running support tool Ro, respectively. As a result, the gripping tool Ci traveling on the inner gripping tool traveling support tool Ri becomes a positional relationship that advances with respect to the gripping tool Co traveling on the outer gripping tool traveling support tool Ro.

That is, the gripping tool Ci and the gripping tool Co, which were opposed to the traveling direction D1 of the long film at the entrance of the diagonal stretching device, are in the position B, and the gripping tool Ci and the gripping tool Co are in the position B. The straight line connecting the two is inclined by an angle θL with respect to the direction substantially perpendicular to the traveling direction (traveling direction after stretching) D2 of the long stretched film.

With the above actions, the long film is stretched diagonally in the direction of θL. Here, substantially vertical means that it is in the range of 90 ± 1 °.

The diagonally stretchable stretching device is a device that heats a long film to an arbitrary temperature that can be stretched and diagonally stretches the film. This stretching device includes a heating zone (heating furnace), a plurality of gripping tools paired on both sides for gripping and traveling on both sides of a long film, and gripping tool traveling for supporting the traveling of the gripping tool. It is equipped with a support.

Both ends of the long film sequentially supplied to the inlet portion (grasping start point) of the stretching device are gripped with a gripping tool, the long film is guided into the heating furnace, and the long film is gripped at the outlet portion (grasping release point) of the stretching device. Release the long stretched film from the tool. The long stretched film released from the gripper is wound around the core. The gripping tool traveling support provided with the gripping tool has an endless continuous trajectory, and the gripping tool released from gripping the long stretched film at the outlet of the stretching device is sequentially returned to the gripping start point by the gripping tool traveling support tool. It is designed to be used.

The gripping tool traveling support may be, for example, a form in which an endless chain whose path is regulated by a guide rail or a gear is provided with a gripping tool, or a form in which an endless guide rail is provided with a gripping tool. There may be. That is, in the present invention, the gripping tool traveling support may be, for example, an endless guide rail provided with an endless chain, or an endless guide rail provided with an endless chain. , It may be an endless guide rail without a chain. When the gripping tool running support does not have a chain, the gripping tool travels along the path of the gripping tool running support itself, and when the gripping tool has a chain, the gripping tool travels along the path of the gripping tool running support via the chain. Run. Hereinafter, in the present invention, a case where the gripping tool travels along the path of the gripping tool traveling support is described as an example, but the gripping tool follows the path of the gripping tool traveling support via a chain provided with the gripping tool. You may run.

The number of gripping tools provided on each gripping tool traveling support is not particularly limited, but the number is preferably the same.

The gripping tool running support of the stretching device has an asymmetrical shape on the left and right, and the path pattern of the gripping tool running support depends on the orientation angle, stretching magnification, etc. given to the long stretched film to be manufactured. It can be adjusted manually or automatically.

In the stretching device of the present embodiment, it is preferable that the path of each gripping tool traveling support can be freely set and the pattern of the path of the gripping tool traveling support can be arbitrarily changed.

The length (total length) of the gripping tool traveling support is not particularly limited, and is usually about 10 to 100 m. Further, the total length of the gripping tool traveling support on both sides may be the same or different.

In the embodiment of the present invention, the traveling speed of the gripping tool of the stretching device can be appropriately selected, but 15 to 150 m / min is particularly preferable. When the traveling speed of the gripping tool of the stretching device becomes higher than 150 m / min, the local stress applied to the edge of the film increases at the bent portion, wrinkles and deviations occur at the edge of the film, and after the stretching is completed. Of the total width of the obtained film, the effective width obtained as a good product tends to be narrow.

In the present invention, the traveling speeds of the two gripping tools constituting the gripping tool pair may be the same or different. If there is a difference in running speed between the left and right sides of the long stretched film at the outlet of the stretching process, wrinkles and deviations may occur at the exit of the stretching process. It is preferable that the speed is constant.

In the present invention, it is preferable that the gripping tool travels at a constant distance from the front and rear gripping tools.

When the traveling speed of the gripping tools constituting the gripping tool pair is set to a constant speed, the difference in the traveling speed of each gripping tool is preferably 1% or less, more preferably 0.5% or less, still more preferably. Is 0.1% or less. In general stretching devices, there is speed unevenness that occurs on the order of seconds or less depending on the period of teeth of the sprocket (gear) that drives the chain, the frequency of the drive motor, etc., and often causes unevenness of several percent. Does not correspond to the speed difference described in this embodiment.

In the oblique stretching device used in the present invention, a large bending rate is often required for the gripping tool traveling support that regulates the trajectory of the gripping tool, especially in a place where the long film is transported at an angle. In order to avoid interference between the gripping tools due to sudden bending or local stress concentration, it is desirable that the locus of the gripping tool is curved so as to draw an arc at the bent portion.

At the entrance of the diagonal stretching device (position of the straight line A in FIG. 7), both ends of the long film are sequentially gripped by the left and right gripping tools (a pair of gripping tools), and the long film is traveled along with the running of the gripping tools. At the entrance of the diagonal stretching device, the gripping tool pair facing in a direction substantially perpendicular to the traveling direction D1 of the long film travels on a left-right asymmetrical path and has a preheating zone, a stretching zone, and a heat fixing zone. Pass through the furnace.

The preheating zone refers to a section in which the gripping tools gripping both ends of the furnace travels while maintaining a constant distance at the inlet of the heating furnace.

The extension zone refers to a section in which the distance between the gripping tools that grip both ends begins to open and the distance becomes a predetermined distance. In the present embodiment, it is possible to stretch in the diagonal direction in the stretching zone, but the stretching is not limited to the diagonal direction, and the stretching may be performed laterally in the stretching zone and then diagonally stretched, or further after the diagonal stretching. It may be stretched in the width direction.

The heat-fixing zone refers to a section in which the gripping tools at both ends run while maintaining parallelism with each other during a period in which the distance between the gripping tools after the stretching zone becomes constant again. After passing through the heat fixing zone, the zone may pass through a section (cooling zone) in which the temperature in the zone is set to be equal to or lower than the glass transition temperature Tg ° C. of the acrylic resin constituting the long film. At this time, in consideration of the shrinkage of the long stretched film due to cooling, the path pattern may be set so as to narrow the distance between the gripping tools facing each other in advance.

Lateral stretching and longitudinal stretching may be performed as necessary in the steps before and after introducing the long film into the diagonal stretching device for the purpose of adjusting the mechanical properties and optical characteristics of the film.

The temperature of each zone is in the range of Tg-10 to Tg + 30 ° C, the temperature of the stretching zone is in the range of Tg-10 to Tg + 30 ° C, and the temperature of the cooling zone is Tg with respect to the glass transition temperature Tg of the acrylic resin. It is preferable to set it in the range of -30 to Tg + 10 ° C.

In addition, in order to control the thickness unevenness in the width direction, a temperature difference may be provided in the width direction in the stretching zone. In order to make a temperature difference in the width direction in the stretching zone, there are known methods such as adjusting the opening of the nozzle that sends warm air into the constant temperature room so as to make a difference in the width direction, and controlling the heating by arranging the heaters in the width direction. Method can be used. The length of the preheating zone, the stretching zone and the heat fixing zone can be appropriately selected, and the length of the preheating zone is usually in the range of 100 to 150% and the length of the heat fixing zone is usually 50 to 50% with respect to the length of the stretching zone. It is in the range of 100%.

The stretching ratio R (W / W0) in the stretching step is preferably in the range of 1.3 to 3.0, more preferably in the range of 1.3 to 2.5. When the draw ratio is in this range, the thickness unevenness in the width direction becomes small, which is preferable. Further, if the stretching temperature is set so as to make a difference in the stretching temperature in the width direction in the stretching zone as necessary, it becomes possible to further suppress the thickness unevenness in the width direction. W0 represents the width of the long film before stretching, and W represents the width of the long stretched film after stretching.

The diagonal stretching step of the manufacturing method of the present embodiment will be described more specifically with reference to FIG. FIG. 8 is a schematic view of a stretching device used in the manufacturing method of the present embodiment.

As shown in FIG. 8, the oblique stretching device 401 has gripping tool traveling supports 402 on both sides of the long film F on which a gripping tool (not shown) for gripping the long film F runs. The gripping tool traveling support tool 402 is arranged so that a part thereof passes through the heating furnace 403.

As described above, the heating furnace 403 is divided into a plurality of zones in the furnace. FIG. 8 illustrates a case where the zone is divided into three zones, a preheating zone, a stretching zone 404, and a heat fixing zone. Further, the gripping tool traveling support tool 402 has a side wall 406 at least in the extension zone 404.

The side wall 406 is provided in the extension zone 404 along the gripping tool running support 402 on both sides. The side wall 406 can block the convection of air generated by the traveling long film and prevent the transfer of heat from the long film F to the extra space. Therefore, the long film F is stretched in the stretch zone in a state where heat is sufficiently and uniformly applied without temperature unevenness. As a result, a long stretched film having stable quality can be obtained with little variation in the orientation angle of the obtained long film in the width direction.

The method of installing the side wall 406 is not particularly limited, and the side wall 406 can be installed in the vicinity of the gripping tool traveling support tool 402 or integrally provided with the gripping tool traveling support tool 402. When the side wall 406 is installed in the vicinity of the gripping tool traveling support tool 402, it is preferable to install the side wall 406 stably by sticking to the installation surface of the heating furnace 403 or the gripping tool traveling support tool 402. As shown below, the side wall 406 is preferably provided integrally with the gripping tool traveling support tool 402 from the viewpoint of following the movement of the gripping tool traveling support tool 402.

When changing the stretching direction of the diagonal stretching device 401, it is preferable that the side wall 406 moves following the movement of the gripping tool traveling support tool 402.

That is, when the stretching angle is changed, the shape, position, and orientation of the side wall 406 (hereinafter, may be collectively referred to as a shape or the like) change according to the shape of the gripping tool traveling support tool 402 before and after the change. Is preferable. In this way, the side wall 406 moves following the movement of the gripping tool traveling support 402, so that the shape of the side wall 406 is adjusted according to the path pattern of the gripping tool traveling support after the movement. Therefore, it is possible to reduce the variation in the orientation angle of the obtained long stretched film in the width direction regardless of the stretching angle, and it is possible to manufacture a long stretched film capable of obtaining a long stretched film of stable quality. can.

As described above, the method of making the side wall 406 follow the movement of the gripping tool traveling support 402 is not particularly limited. For example, a tenter clip 300 as shown in FIG. 6 may be used.
When the tenter clip 300 grips the wet film 301 at both ends, a temperature difference due to the temperature of the tenter clip 300 may occur between the central portion (non-grasping portion) and both ends (grip portion) of the film. Since this temperature difference may cause uneven film thickness, it is preferable to heat or cool the tenter clip 300 with a blower 311a. On the contrary, for the purpose of controlling the biting of the film 301 into the tenter clip 300, heating or cooling is also performed so that the temperature of the grip portion 300a is positively different from that of the non-grip portion. Heating / cooling may be performed while the tenter clip 300 is not gripping the film 301.

In this way, by providing the side wall 406 integrally with the gripping tool traveling support tool 402 so that it can move following the movement of the gripping tool traveling support tool 402, the shape of the side wall 406 and the like can be changed to the gripping tool traveling support tool 402. The shape of the support 402 is changed at the same time as the shape is changed. As a result, sufficient and uniform heat is continuously applied to the long film F regardless of the stretching angle, and as a result, a long stretched film of stable quality with little variation in the orientation angle in the width direction can be obtained. sell.

The material constituting the side wall 406 is not particularly limited, and a side wall 406 made of resin or metal can be adopted. Further, the side wall 406 does not need to be formed of a single member, and a plurality of members may be connected by a hinge or the like.

Further, the surface of the side wall 406 is preferably made of or coated with a heat insulating material in order to prevent heat transfer from the long film F to the extra space.

The height of the side wall 406 is not particularly limited, and may be a height that can prevent heat from entering and exiting between the long film F and the extra space in consideration of the internal shape of the heating furnace 403 and the like. .. In particular, the height of the side wall 406 is preferably such that it does not come into contact with the inside of the heating furnace 403 so that it can move following the movement of the gripping tool traveling support tool 402 when the stretching angle is changed. ..

The thickness of the side wall 406 is not particularly limited, and may be a thickness that can prevent heat from entering and exiting the long film F and the extra space. In particular, the thickness of the side wall 406 is such that it does not hinder the bending or rotation of the side wall 406 when the side wall 406 moves following the movement of the gripping tool traveling support tool 402 when the stretching angle is changed. Is preferable.

In the manufacturing method of the present embodiment, as shown in FIG. 8, the side wall 406 is provided along at least the gripping tool running support 402 passing through the extension zone 404. Therefore, even when the stretching angle of the long film F is changed, the stretched long film F has sufficient and uniform heat without temperature unevenness regardless of changes in the volume and position of the extra space. Granted. As a result, in the obtained long stretched film, variation in the orientation angle of the long film F in the width direction is suppressed regardless of the stretching angle.

As shown in FIG. 8, when the side wall 406 is provided only in the stretched zone 404, the heat from the long film F can be transferred to the extra space in the zone where the side wall 406 is not provided. There is sex. However, as described above, the long film F is only preheated in the preheating zone before the stretching zone, and is only heat-fixed so as not to shrink in the heat fixing zone after the stretching zone. Therefore, even if the temperature unevenness occurs in the long film F in these zones, the influence on the variation in the orientation angle of the obtained long stretched film in the width direction is small. As a result, according to the manufacturing method of the present embodiment, since the side wall 406 is provided at least in the stretching zone, the variation in the orientation angle of the obtained long stretched film in the width direction can be sufficiently reduced.

Further, as another example of the manufacturing method of the present embodiment, the side wall 406 can be provided along the entire gripping tool traveling support tool 402 installed in the heating furnace 403. In this way, by providing the side wall 406 in all the zones in the heating furnace 403, the long film F traveling in the heating furnace 403 is more reliably blocked from the heat inflow and outflow between the long film F and the extra space. It is possible to apply heat sufficiently and uniformly over the entire area. Further, even when the stretching angle is changed, sufficient and uniform heat is applied to the traveling long film F regardless of changes in the volume and position of the extra space. As a result, the temperature unevenness of the obtained long stretched film can be more reliably suppressed, and the variation in the orientation angle of the long stretched film in the width direction can be reduced regardless of the stretching angle.

FIG. 8 shows only the section in which the gripping tool holding the long film F travels (hereinafter, this section may be referred to as an outward route section) among the gripping tool traveling support tools 402, and the gripping tool is used. The section of traveling after releasing the grip of the long film F (hereinafter, this section may be referred to as a return section) is omitted. The gripping tool traveling support tool 402 in the return route section may be arranged inside the heating furnace 403 or may be provided outside the heating furnace 403.

Then, for example, when the gripping tool traveling support 402 in the return route section is provided in the heating furnace 403 and is provided in the vicinity of the gripping tool traveling support tool 402 in the outward route section, the side wall 406 , The gripping tool traveling support tool 402 in the outward route section may be provided, the gripping tool traveling support tool 402 in the return route section may be provided, or the gripping tool traveling support tool 402 in both sections may be provided. That is, the side wall 406 may be arranged at a position where the heat transfer from the long film F to the extra space can be blocked. As described above, when the gripping tool traveling support tool 402 in the return route section is provided in the heating furnace 403 and is provided in the vicinity of the gripping tool traveling support tool 402 in the outward route section, the return route section By providing the gripping tool traveling support tool 402, it is possible to block the transfer of heat from the long film F to the extra space.

(Wet stretching)
The acrylic resin film according to the present invention can also be wet-stretched on an unstretched film. By such wet stretching, a polymer-oriented film in which the polymer chains are oriented can be obtained.

Wet stretching is a general term for stretching methods that substantially use water as a means to soften the film immediately before stretching, in which water acts as a substantial plasticizer for the main polymer material of the film. ing. It is well known that the film is usually softened by the amount of the plasticizer in order to plasticize the resin film, and the wet stretching used in the present invention is basically based on this idea.

As described above, in the production of the film of the present invention, it is important how much the film is softened (plasticized) by water at the time of stretching, and how much water is contained in the film, that is, the water content is known. This is very important.

[Moisture content]
The water content is the mass fraction (%) of the water contained in the film. Actually, when the water content (μg) indicated by the moisture meter is W and the weighed sample amount is F (mg), the water content is It is represented by (mass%) = 0.1 × (W / F).

Actually, considering the material of the film of the present invention, the polymer material of the acrylic resin film according to the present invention has a water content of about 0.01% at room temperature. Usually, such an acrylic resin film (raw fabric) is brought into a stretchable state by raising the temperature to about the glass transition temperature (Tg), and stretching is performed. When the temperature is about Tg, for example, 130 ° C., the water content is further reduced to 0.001% by mass. In the present invention, by impregnating such a cyclic polyolefin film (raw fabric) before stretching, the water content of the acrylic resin film is in the range of 0.001 to 1% by mass, more preferably 0.001 to 0.5% by mass. %, More preferably 0.005 to 0.3% by mass.

Setting the water content of the film during stretching in the range of 0.001 to 1% by mass makes the glass transition temperature (Tg) of the acrylic resin film from 130 ° C (water content 0.001% by mass) to 75 ° C (water content). It will be reduced to 0.005% by mass), and uniform stretching will be possible at a temperature lower than the normal stretching temperature (130 ° C.). The Tg of the acrylic resin film having a water content of 5.5% by mass is obtained by putting water in a silver sealing pan (70 μl) and immersing the acrylic resin film to obtain a temperature-modulated DSC (DSC2910 manufactured by TA Instruments). It was measured using.

In order to control the water content of the film at the time of stretching, the film may be immersed in water before stretching, or the humidity may be adjusted at a constant temperature and high humidity, or these two may be used in combination. You may. When immersed in a water tank, the temperature of the water is preferably in the range of 50 to 100 ° C, more preferably in the range of 60 to 95 ° C, and particularly preferably in the range of 70 to 90 ° C. The immersion time is preferably in the range of 5 seconds to 10 minutes, more preferably in the range of 10 seconds to 8 minutes, and particularly preferably in the range of 20 seconds to 6 minutes. When the humidity is controlled at a constant temperature and high humidity, the temperature is preferably in the range of 50 to 150 ° C, more preferably in the range of 60 to 140 ° C, and particularly preferably in the range of 70 to 120 ° C. The relative humidity is preferably in the range of 60 to 100% or less.

The water used for these immersion and steam aeration may be substantially water. Substantially, water means water in an amount of 60% by mass or more, and may contain the following organic solvent, plasticizer, surfactant and the like in addition to water. Preferred organic solvents include water-soluble organic solvents having 1 to 10 carbon atoms. However, more preferably 90% by mass or more is water, further preferably 95% by mass or more is water, and most preferably pure water is used. The water used in the following description may be substantially water.

The atmosphere at the time of stretching may be air, steam, or water. The atmosphere at the time of stretching in the air means stretching in an atmosphere in which the temperature is controlled and the humidity is not controlled. The stretching temperature is preferably in the range of 50 to 150 ° C, more preferably in the range of 60 to 130 ° C, and particularly preferably in the range of 65 to 110 ° C. The atmosphere at the time of stretching in water vapor means that the temperature is constant and high humidity, or that water vapor is applied to the film. The stretching temperature is preferably in the range of 50 to 150 ° C, more preferably in the range of 60 to 140 ° C, and particularly preferably in the range of 70 to 130 ° C. The relative humidity is preferably in the range of 60-100%. By doing so, the water content in the film of the present invention, particularly the acrylic resin, is maintained in the range of 2.0 to 20.0% by mass. When the water content is smaller than 2.0% by mass, the elongation at break is small at the time of stretching, and it becomes easy to cut, and the desired retardation may not be reached.

The atmosphere at the time of stretching is water, which means that the film is stretched while being immersed in a water tank. The temperature of the water is preferably in the range of 50 to 100 ° C, more preferably in the range of 60 to 98 ° C, and particularly preferably in the range of 65 to 95 ° C. The immersion time is preferably in the range of 0.5 seconds to 10 minutes, more preferably in the range of 1 second to 8 minutes, and particularly preferably in the range of 1 second to 7 minutes.

Assuming that the distance between the fixing members that fix the film during stretching is L, the direction perpendicular to the fixing members is W, and the aspect ratio of the film shape during stretching is L / W, the aspect ratio is 0.1 to 10. The range of 0.1 to 8.0 is preferable, the range of 0.1 to 8.0 is more preferable, and the range of 0.1 to 6.0 is particularly preferable. The term "at the time of stretching" as used herein means the aspect ratio of the film before stretching.

Keeping the water content immediately after stretching in the range of 0.001 to 1% by mass is essential for the film to be uniformly stretched. Since the water content of the film is controlled in the range of 0.001 to 1% by mass in the zone immediately before stretching, if the water content is 1.0% by mass or less, the elongation at break becomes small, and the front surface has a desired thickness. The retardation cannot be output up to the λ / 4 region. Here, the water content immediately after stretching refers to the water content of the film immediately after the stretching step is completed. Further, after the stretching step, the water adhering to the film may be removed up to the winding site. A known method such as an air knife method or a blade method can be used.

(5) Winding Step An example of the winding device used in the present invention is shown in FIGS. 9 and 10.

As shown in FIGS. 9 and 10, the take-up device 519 preferably includes a take-up unit 551 and further preferably a tension control unit 552.

The take-up unit 551 includes a rotary shaft 555, a core holder 556, a turret 557, a motor 558, a shift mechanism 561, and controllers 562 and 563.

The rotation shaft 555 is arranged so that the longitudinal direction is the B direction. The rotary shaft 555 is supported by rotatably attaching one end in the longitudinal direction to the turret 557. A motor 558 is connected to the rotary shaft 555, and the motor 558 rotates the rotary shaft 555 in the circumferential direction. A controller 562 is connected to the motor 558. When a signal of the target rotation speed of the rotation shaft 555 is input, the controller 562 controls the motor 558 based on the input signal. As a result, the rotation shaft 555 rotates at the target rotation speed.

A pair of recesses extending in the longitudinal direction are formed on the outer periphery of the rotating shaft 555. A pair of convex portions extending in the longitudinal direction of the winding core 566 are formed on the inner circumference of the tubular winding core 566 around which the film 527 is wound. The convex portion of the winding core 566 enters the concave portion of the rotating shaft 555 to engage with the winding core 566, and the winding core 566 is set on the rotating shaft 555. As a result, the winding core 566 rotates integrally with the rotating shaft 555.

A pair of winding core holders 556 that hold the winding core 566 from both ends in the longitudinal direction are provided at both ends of the rotating shaft 555 in the longitudinal direction. The winding core holder 556 is slidable in the longitudinal direction of the rotating shaft 555, and by sliding, the winding core 566 is displaced in the B direction.

A shift mechanism 561 is connected to the core holder 556, and the shift mechanism 561 displaces the core holder 556 along the longitudinal direction of the rotary shaft 555. Due to this displacement, the winding core 566 is displaced in the B direction.

A controller 563 is connected to the shift mechanism 561. When the controller 563 inputs a signal of each target value of the direction in which the winding core holder 556 should be moved in the longitudinal direction of the rotating shaft 555, the moving speed, and the displacement amount, the winding core 563 is based on this input signal. Controls the holder 556. As a result, the winding core holder 556 is displaced on the rotating shaft 555 during rotation at a target timing and speed with a target displacement amount.

The tension control unit 552 preferably includes guide rollers 571 and 572, a dancer roller 573, a shift mechanism 576, and a controller 577.

The guide rollers 571 and 572 form a transport path for the film 527 from the second slitter 518 to the take-up unit 551, and support the film so as to guide the film 527 to the take-up unit 551. The guide rollers 571 and 572 may be drive rollers having a drive means, or may be so-called free rollers that rotate when they come into contact with the film 527 being conveyed.

The dancer roller 573 is arranged between the guide rollers 571 and the guide rollers 57 2 arranged in the transport direction of the film 527. The film 527 is wound around the dancer roller 573 so that the film surface opposite to the film surface in contact with the guide roller 571 and the guide roller 57 2 comes into contact with the dancer roller 573.

The shift mechanism 576 is connected to the dancer roller 573 and displaces the step roller 573 in the direction intersecting the film surface. Due to this displacement, the tension in the longitudinal direction of the film 527 changes. When a signal of the displacement amount of the dancer roller 573 is input, the shift mechanism 576 displaces the dancer roller 573 by the target displacement amount based on this input signal.

The controller 577 is connected to the shift mechanism 576, and when a signal corresponding to the target value of the tension in the longitudinal direction of the film 527 is input, the displacement amount of the dancer roller 573 is obtained based on this input signal, and the obtained displacement is obtained. A quantity signal is output to the shift mechanism 576.

It is preferable that the guide roller 572 on the downstream side is provided with a tension sensor (not shown) for detecting the tension in the longitudinal direction of the film 527. In this case, it is more preferable to provide a calculation unit 578 connected to the controller 577 and the tension sensor of the guide roller 572. When the detection signal of the tension sensor is input, the calculation unit 578 obtains the difference between the target value of tension and the target value of tension corresponding to the detection signal, and corresponds to the target value of tension when the difference is not 0 (zero). The signal is output and sent to the controller 577.

The tip of the film 527 in the longitudinal direction is wound around the winding core 566 set in the winding unit 551 to drive the motor 558. The guided film 527 is wound up by the drive of the motor 558. While winding the guided film 527, the shift mechanism 561 displaces the core holder 556 in the B direction, whereby the core 566 is reciprocated in the B direction. By this reciprocating motion, the guided film 527 is wound around the winding core 566 while forming a roll in which the welded portion upper forming region 527w is displaced in the B direction. The welded portion upper region 527w of the film 527 is a region corresponding to the welded portion upper region of the casting film 539 formed on the welded portion 533w of the band 533. The details of the welded portion upper forming region 527w will be described later with reference to another drawing.

The shift mechanism 561 displaces the winding core holder 556 with a constant amplitude in the B direction, and the reciprocating movement of the winding core 566 in the B direction also has a constant amplitude. As a result, the film 527 is wound around the core 566 while the region 527w formed on the welded portion of the film 527 is displaced by a constant amplitude in the longitudinal direction of the core 566. In the obtained film roll, the welded portion upper formed region 527w is wound while being displaced with a constant amplitude in the width direction of the film 527, and there is no black streak due to the overlap of the welded portion upper formed region 527w.

The welded portion upper forming region 527w will be described with reference to FIG. As described above, the flow film 539 is formed in a range extending from one of the side portions 533s of the band 533 to the other, so that it is also formed on the welded portion 533w. The welded portion 533w has a substantially constant width. The width of the welded portion 533w is about 10 mm even when the band 533 is manufactured with extremely high accuracy. However, depending on the accuracy of the band 533, the width of the welded portion 533w may be non-uniform in the longitudinal direction or may be larger than 10 mm. The welded portion 533w is a region formed as a weld bead when the narrow sheet for the side portion 533s and the wide sheet for the central portion 533c, which are used as raw materials for manufacturing the band 533, are welded. The welded portion 533w can be visually recognized even after post-treatment such as polishing after welding.

The region formed on the welded portion 533w in the casting film 539 is referred to as a welded portion upper region 539w. Since the welded portion 533w can be visually specified as described above, the welded portion upper region 539w is specified as a region on the welded portion 533w.

The cast film 539 is peeled off at the peeling position PP, then transported, and is subjected to various treatments by the first slitter, the first tenter, the second tenter, the second slitter, and the like. By these treatments, tension is applied to the film 527 in the A direction and the B direction, and the side end portion in the B direction is cut off. As a result, the film 527 stretches in the longitudinal direction, dries and shrinks in the width direction, or is stretched in the width direction to widen the film 527 from the time it is peeled off at the stripping position PP to the time it is wound up by the winding device. The width is narrowed by cutting or excision.

Therefore, the widths of the cast film and the film 527 are usually different. Further, the position and width W539 of the welded portion upper region 539w in the width direction of the casting film and the position and width W527 of the welded portion corresponding region 527w in the width direction of the film 527 are usually different from each other.

However, even if the welded portion corresponding region 527w is displaced so as to have an amplitude in the width direction of the film 527, the welded portion corresponding region 527w cannot be visually confirmed in the film 527 at the time of winding. Therefore, the welded portion corresponding region 527w at the time of winding may be specified by the following method. The film 527 at the time of winding corresponds to the film 527 at the winding position PW in this embodiment. However, since the film 527 for a certain period of time before winding has been sufficiently dried, the change in dimensions is extremely small. Therefore, the film upstream from the take-up position PW may be regarded as the film 527 at the time of take-up. The winding position PW is a position where the film 527 wound around the winding core 566 comes into contact with the outer peripheral surface of the film 527 already wound around the winding core 566.

First, marking is made on the welded portion upper region 539w of the cast film at the stripping position PP. In the following description, this mark will be referred to as a flow film mark, and will be designated by the reference numeral M539 in FIG. The marking may be performed with an ink having resistance to a solvent or the like. When the flow film mark M539 reaches the take-up position PW, the region where the flow film mark M539 is located is specified as a welded portion corresponding region 527w. The mark attached to the specified welded portion corresponding region 527w is referred to as a film mark in the following description, and is designated by the reference numeral M527 in FIG.

FIG. 11 shows a case where the film mark M527 is larger than the cast film mark M539, but it may be smaller or substantially the same size depending on the conditions of the steps after stripping. , The ratio of width to length in the longitudinal direction (hereinafter simply referred to as "ratio of width to length") may change. However, it is not necessary to consider the size relationship and the ratio relationship between the width and the length of the film mark M527 and the flow film mark M539, and it is sufficient to detect the width of the film mark M527. The width of the film mark M527 is the width W527 of the welded portion corresponding region 527w.

In FIG. 11, for convenience of explanation, the widths of the welded portion 533w, the welded portion upper region 539w, and the welded portion upper forming region 527w are exaggerated with respect to the widths of the band 533, the casting film 539, and the film 527. It is drawn large.

As described above, the welded portion corresponding region 527w is specified, and the film 527 is wound around the winding core 566 while forming a roll in which the welded portion corresponding region 527w is displaced in the B direction by the winding device 519, whereby the welded portion 533w is formed. The resulting black streaks on the film roll are prevented.

Further, it is preferable that the period of displacement of the winding core 566 having an amplitude in the B direction is the time during which the traveling band 533 makes one revolution. The time required for the band 533 to make one round is the time required for an arbitrary part of the traveling band 533 to return from the specified position of the traveling path of the band 533 to the specified position, for example, the spreading position. It is the time until the portion of the band 533 in the PC returns to the flow position PC again. This time can be obtained, for example, by marking an arbitrary portion of the band 533 and measuring the time from the time when this mark passes through the spreading position PC to the time when the mark passes next time.

By setting the displacement cycle of the winding core 566 to be the time for the traveling band 533 to make one round, the position of the formed region 527w on the welded portion of the film 527 is set to the length obtained by the time for making one round of the band 533. A film roll having a displacement amount that oscillates in the width direction can be obtained. This more reliably prevents the formation of black streaks on the film roll. It should be noted that the displacement cycle of the winding core 566 does not have to be strictly the time for one round of the band 533, and a certain effect can be obtained if it is substantially the same as the time for one round.

The displacement cycle of the winding core 566 can be controlled by the displacement cycle of the winding core holder 556. Therefore, when setting the displacement cycle of the winding core 566, the controller 563 may control the shift mechanism 561 based on the input signal when the time for making one round of the band 533 is input.

The amplitude of the displacement of the welded portion corresponding region 527w in the B direction may be changed according to the width W527 of the welded portion corresponding region 527w. Specifically, the larger the width W527 of the welded portion corresponding region 527w, the larger the amplitude of the displacement of the welded portion corresponding region 527w in the B direction. This is particularly effective when the welded portion 533w is in a substantially straight line extending in the longitudinal direction of the band 533. The fact that the welded portion 533w is a substantially straight line extending in the longitudinal direction of the band 533 means that the amplitude of the welded portion 533w in the B direction is within about 2 mm. The amplitude corresponds to half of the displacement amount in the B direction.

When the width W527 of the welded portion corresponding region 527w is constant at about 10 mm, it is effective if the displacement amplitude of the welded portion corresponding region 527w in the B direction is about 10 mm.

Further, when the longitudinal direction of the band 533 corresponds to the cycle and the welded portion 533w meanders so as to draw a sine curve (SINE CURVE), the welded portion corresponding region 527w also indicates that the longitudinal direction corresponds to the cycle. It meanders like a curve. In this case, if the film 527 is made to be in phase with the sine curve of the welded portion corresponding region 527w in synchronization with the sine curve, the amplitude of the displacement of the welded portion corresponding region 527w in the B direction can be suppressed to be smaller. Is preferable.

The size of the film to be wound in the winding device 519 is not particularly limited, but for example, it is preferable that the total winding length is in the range of 2000 to 10000 m and the width is in the range of 500 to 2500 mm. ..

It is preferable to perform static elimination treatment in the winding step. The static elimination process will be described in detail.

FIG. 12 is a schematic view of the present invention from the drying step to the winding step, and static elimination devices (blower type static elimination devices) 620, 621, and 622 are provided between the cooling chamber 607 and the winding chamber 610. Further, the pass rollers 623 and 624 are grounded, and the surface potential meters 625 and 626 are provided close to the pass rollers 623 and 624, respectively.

The film 601 that has left the drying chamber 605 while passing through the pass roller 604 is statically eliminated while being cooled to room temperature by the static elimination device 620 in the cooling chamber 607. The static elimination device 620 directly applies the generated ions to the film 601 by a blower to eliminate static electricity. By installing this static eliminator 620 in the drying chamber 605, the charging potential of the film can be lowered. FIG. 13 is an outline of the static elimination treatment of the film 601 performed in the cooling chamber 607 by the ventilation type static elimination device 620. As shown in FIG. 13, the blower type static eliminator 620 generates ions by an ion generator 620b housed in the blower head 620a, blows air from the blower 620c through the ventilation duct 620e, and blows ion air from the slit 620d. Discharge towards film 601. In addition, in order to measure the charging voltage of the film at the time of leaving the drying chamber 605, the pass roller 623 is grounded, and the surface electrometer 625 is used for the film 601 in contact with the pass roller 623. It is preferable to measure the surface potential. In this case, if the static electricity is not eliminated to a predetermined charging potential based on the measured surface potential, the amount of ion wind generated is controlled so that the surface potential is within an appropriate range of -10 to + 10V. ..

Further, the film 601 exiting the cooling chamber 607 is statically eliminated by using the static elimination device 621. Further, using the knurling roller 609, knurling is applied to both ends of the film 601 by embossing. FIG. 13 shows an example in which the static eliminator device 621 is provided on the upstream side of the knurling roller, but the position is not limited to that.

Next, in the winding chamber 610, the pass roller 624 is grounded, a surface electrometer is installed on the film 601 in contact with the pass roller 624, and the surface potential of the film 601 is measured. Then, the amount of ion wind generated is controlled based on the measured surface potential so that it is within an appropriate surface potential, for example, −5 to + 5V, and static elimination is performed using the static elimination device 622 immediately before winding. , Touch roller 612 and take-up roller 611.

Although the static elimination devices 621 to 623 are blown with ionized wind to eliminate static electricity, they may be statically eliminated by various well-known static elimination devices. Further, from the surface potential values measured by the surface electrometers 625 and 626, each static elimination device is controlled by using a controller (not shown) to perform more uniform static elimination, but these surface electrometers are used. May be omitted, and static elimination may be performed simply by using various static elimination devices.

It is also preferable that the acrylic resin film according to the present invention is formed into a laminated film by laminating a protective film at the time of winding.

(Protective film)
The protective film is a film that can be bonded and peeled off from an acrylic resin film. By attaching the protective film to the acrylic resin film, it is possible to prevent the surface of the acrylic resin film from being scratched and to improve the handling property.

The arithmetic mean roughness Ra of the surface of the protective film opposite to the surface to be bonded to the acrylic resin film is usually 0.2 μm or more, preferably 0.3 μm or more, more preferably 0.5 μm or more, and is usually 1. It is 4 μm or less, preferably 1.0 μm or less, and more preferably 0.8 μm or less. Normally, the surface of the protective film to be attached to the acrylic resin film is an adhesive surface. Therefore, usually, the arithmetic average roughness Ra of the surface of the protective film that is not the adhesive surface is set to fall within the above range.

According to the study of the present inventor, the arithmetic mean roughness Ra of the surface of the protective film opposite to the acrylic resin film is largely related to the generation of wrinkles and gauge bands of the acrylic resin film roll. Conceivable. When the multi-layer film is wound as an acrylic resin film roll, the surface of the multi-layer film on the acrylic resin film side and the surface on the protective film side come into contact with each other due to the overlapping of the multi-layer films. At this time, the surface roughness of the surface of the multi-layer film on the protective film side (that is, the surface roughness of the surface of the protective film opposite to the acrylic resin film) is the amount of air entrained and discharged between the multi-layer films. Has a great effect on.

Specifically, if the surface of the surface of the multi-layer film opposite to the acrylic resin film becomes rough, the amount of air entrained between the multi-layer films during winding increases, causing deformation and wrinkles. It will be easier. Further, if the surface roughness of the surface of the multi-layer film opposite to that of the acrylic resin film is rough, the air passage becomes large and the entrained air can easily escape. Then, when the thickness of the air layer changes due to air bleeding between the multilayer films, the multilayer film deforms according to the change in the thickness, so that wrinkles occur on the acrylic resin film roll. Cheap. Therefore, in the present embodiment, wrinkles are prevented by setting the arithmetic average roughness Ra of the surface of the protective film opposite to the acrylic resin film to be equal to or less than the upper limit of the above range.

On the other hand, if the surface of the surface of the multi-layer film opposite to the acrylic resin film is smooth, the amount of air entrained between the multi-layer films at the time of winding is small, and a gauge band is likely to occur. Therefore, in the present embodiment, the gauge band is prevented by setting the arithmetic average roughness Ra of the surface of the protective film opposite to the acrylic resin film to be equal to or higher than the lower limit of the above range.

The composition and layer composition of the protective film are arbitrary as long as the effects of the present invention are not significantly impaired. For example, the protective film may be a single-layer structure film having only one layer, or a multi-layer structure film having two or more layers. The film thickness of the protective film is arbitrary, and may be usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and usually 80 μm or less, preferably 60 μm or less, more preferably 40 μm or less.

Above all, the protective film preferably contains a polyolefin-based polymer. If the protective film is a film having a single-layer structure, it is preferable that the layer contains a polyolefin-based polymer. Further, if the protective film is a film having a multi-layer structure, it is preferable that at least one layer contains a polyolefin-based polymer. By using a polyolefin-based polymer, molding by coextrusion becomes possible, and the productivity is excellent.

The protective film is usually a film having a multi-layer structure including two or more layers. Preferable examples of the protective film include a film having an adhesive layer and a back surface layer; a film having an adhesive layer, an intermediate layer and a back surface layer in this order; and the like. In this case, the surface of the adhesive layer forms the adhesive surface of the protective film.

Hereinafter, examples of suitable components of the protective film will be described.

(Adhesive layer)
The adhesive layer is located on the surface of the protective film on the side of the acrylic resin film and is a layer capable of adhering to the acrylic resin film. The adhesive layer is formed containing an adhesive so that the protective film can be fixed to the acrylic resin film by the adhesive force of the adhesive.

Examples of the pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, polyvinyl ether-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. As the pressure-sensitive adhesive, one type may be used alone, or two or more types may be used in combination at any ratio.

Among the pressure-sensitive adhesives, the general formula ABA or the block copolymer represented by the general formula AB (however, in these formulas, A represents a styrene-based polymer block and B represents a butadiene polymer. A rubber-based pressure-sensitive adhesive containing a block, a polymer block selected from the group consisting of a block, an isoprene polymer block, and an olefin polymer block obtained by hydrogenating these; an acrylic pressure-sensitive adhesive is preferable.

In the block copolymer represented by the general formula ABA or the general formula AB, the styrene-based polymer block A has a weight average molecular weight of 12,000 or more, 100,000 or less, and a glass transition temperature of 20 ° C. or more. Is preferable. Further, the polymer block B selected from the group consisting of a butadiene polymer block, an isoprene polymer block, and an olefin polymer block obtained by hydrogenating these blocks has a weight average molecular weight of 10,000 or more, 300,000 or less, and a glass transition temperature. Is preferably −20 ° C. or lower. Further, the mass ratio of the A component to the B component (A component / B component) is preferably 5/95 or more, more preferably 10/90 or more, preferably 50/50 or less, and more preferably 30/70. It is as follows.

Examples of the block copolymer represented by the general formula ABA include styrene-ethylene / propylene-styrene copolymer, styrene-ethylene / butylene-styrene copolymer, and hydrogenated products thereof. Examples of block copolymers represented by the general formulas AB include styrene-ethylene / propylene copolymers, styrene-ethylene / butylene copolymers, and hydrogenated compounds thereof. can.

Examples of acrylic pressure-sensitive adhesives include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, and octyl. Alkyl (meth) acrylates such as (meth) acrylates, lauryl (meth) acrylates and stearyl (meth) acrylates; alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylates and butoxyethyl (meth) acrylates; cyclohexyl (meth) (Meta) acrylamides such as meta) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, vinyl acetate, (meth) acrylamide, N-methylol (meth) acrylamide; homopolymers or copolymers such as Can be mentioned. In addition, (meth) acrylate means acrylate and methacrylate, and (meth) acrylic means acrylic and methacrylic.

As the acrylic pressure-sensitive adhesive, preferably, an acrylic monomer having a functional group is copolymerized and used. Examples of acrylic monomers having a functional group include maleic anhydride, fumaric acid, unsaturated acids such as (meth) acrylic acid; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2 -Hydroxyhexyl (meth) acrylate, dimethylaminoethyl methacrylate, (meth) acrylamide, N-methylol (meth) acrylamide, glycidyl (meth) acrylate, maleic anhydride and the like can be mentioned. As the acrylic monomer having a functional group, one type may be used alone, or two or more types may be used in combination at any ratio.

The acrylic pressure-sensitive adhesive may contain a cross-linking agent, if necessary. The above-mentioned cross-linking agent is a compound for thermally cross-linking with a functional group existing in the copolymer to finally form an adhesive layer having a three-dimensional network structure. By including a cross-linking agent, it is possible to improve the adhesion of the protective film to other layers (intermediate layer, back layer, etc.) in contact with the adhesive layer, the toughness of the protective film, the solvent resistance, the water resistance, and the like. .. Examples of the cross-linking agent include isocyanate-based compounds, melamine-based compounds, urea-based compounds, epoxy-based compounds, amino-based compounds, amide-based compounds, aziridine compounds, oxazoline compounds, silane coupling agents, and modified products thereof. It may be used as appropriate. One type of cross-linking agent may be used alone, or two or more types may be used in combination at any ratio.

From the viewpoint of cross-linking property and toughness of the adhesive layer, it is preferable to use an isocyanate compound or a modified product thereof as the cross-linking agent. The isocyanate-based compound is a compound having two or more isocyanate groups in one molecule, and is roughly classified into an aromatic-based compound and an aliphatic-based compound. Examples of the aromatic isocyanate-based compound include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, naphthalin diisocyanate, trizine diisocyanate, paraphenylenedi isocyanate and the like. Examples of the aliphatic isocyanate compound include hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, tetramethylxylylene diisocyanate, and xylylene diisocyanate. Further, examples of the modified form of these isocyanate-based compounds include a billet form, an isocyanurate form, and a trimethylolpropane adduct form of the isocyanate-based compound.

When a cross-linking agent is used, a cross-linking catalyst such as dibutyltin laurate may be included in the pressure-sensitive adhesive in order to promote the cross-linking reaction.

The pressure-sensitive adhesive layer may contain a tack-imparting polymer, if necessary. Examples of the tackifier polymer include aromatic hydrocarbon polymers, aliphatic hydrocarbon polymers, terpene polymers, terpenephenol polymers, aromatic hydrocarbon-modified terpene polymers, chroman-inden polymers, and styrene-based polymers. Examples thereof include polymers, rosin-based polymers, phenol-based polymers, and xylene polymers, and among them, aliphatic hydrocarbon polymers such as low-density polyethylene are preferable. However, the specific type of tack-imparting polymer is appropriately selected from the viewpoint of compatibility with other polymers, the melting point of the resin, and the adhesive strength of the pressure-sensitive adhesive layer. Further, as the tackifier polymer, one type may be used alone, or two or more types may be used in combination at any ratio.

The amount of the tackifier polymer is, for example, preferably 5 parts by mass or more, preferably 200 parts by mass or less, and more preferably 100 parts by mass or less with respect to 100 parts by mass of the block copolymer. .. By setting the amount of the tackifier polymer to the lower limit of the above range or more, it is possible to prevent the protective film from floating or peeling off when it is bonded to the acrylic resin film. Further, by setting the value to the upper limit or less, the feeding tension of the protective film is suppressed to prevent wrinkles and scratches when the protective film is bonded to the acrylic resin film, and the adhesive polymer is prevented from bleeding out and adhered. The adhesive strength of the layer can be maintained high.

If necessary, the adhesive layer may contain additives such as a softening agent, an antiaging agent, a filler, and a coloring agent (dye, pigment, etc.). As the additive, one type may be used alone, or two or more types may be used in combination at any ratio.

Examples of the softener include process oils, liquid rubbers, and plasticizers.

Examples of the filler include barium sulfate, talc, calcium carbonate, mica, silica, titanium oxide and the like.

The adhesive strength of the adhesive layer is preferably 0.4 N / cm or more, more preferably 0.6 N / cm or more, and 6 N / cm with respect to other layers (intermediate layer, back surface layer, etc.) in contact with the adhesive layer in the protective film. It is preferably cm or less, and more preferably 4 N / cm or less. By setting the adhesive strength to the lower limit of the above range or more, it is possible to prevent the protective film from floating and peeling when the protective film is attached to the acrylic resin film. Further, by setting the value to the upper limit or less, it is possible to suppress the feeding tension of the protective film and prevent wrinkles and scratches at the time of bonding with the cyclic polyolefin film.

The film thickness of the adhesive layer is usually 1.0 μm or more, preferably 2.0 μm or more, and usually 50 μm or less, preferably 30 μm or less. By setting the thickness of the adhesive layer to the lower limit of the above range or more, the adhesive strength can be increased and the protective film can be prevented from floating and peeling when the protective film is attached to the acrylic resin film. Further, by setting the value to the upper limit or less, it is possible to prevent the adhesive force from becoming excessively high and suppress the feeding tension of the protective film, so that wrinkles and scratches at the time of bonding with the acrylic resin film can be prevented. Further, since it is possible to prevent the protective film from becoming too stiff, the handleability of the protective film can be improved.

(Back layer)
The back layer is a layer located on the side opposite to the acrylic resin film with respect to the adhesive layer, and is usually located on the surface opposite to the acrylic resin film of the protective film. This back layer usually does not adhere to the acrylic resin film. In a protective film provided with a back layer, the arithmetic average roughness Ra of the exposed surface of the back layer is usually the arithmetic average roughness Ra of the surface opposite to the adhesive surface of the protective film.

Usually, the back layer is made of resin. The polymer contained in the resin forming the back layer may be a homopolymer or a copolymer. A suitable example is a polyolefin-based polymer.

The polyolefin-based polymer is a homopolymer or copolymer of a chain olefin, or a copolymer of a chain olefin and a monomer copolymerizable with the chain olefin. Examples include polyethylene, polypropylene, ethylene-propylene copolymer, propylene-α-olefin copolymer, ethylene-α-olefin copolymer, ethylene-ethyl (meth) acrylate copolymer, ethylene-methyl (meth). ) An acrylate copolymer, an ethylene-n-butyl (meth) acrylate copolymer, an ethylene-vinyl acetate copolymer and the like can be mentioned. Here, examples of polyethylene include low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene. Examples of the ethylene-propylene copolymer include a random copolymer and a block copolymer. Further, examples of the α-olefin include butene-1, hexene-1, 4-methylpentene-1, octene-1, penten-1, and heptene-1.

Among the above-mentioned polyolefin-based polymers, a polymer selected from the group consisting of polyethylene, polypropylene, an ethylene-propylene copolymer, and a propylene-α-olefin copolymer is preferable, and both the ethylene-propylene copolymer and the propylene-α-olefin are used. Polymers (hereinafter, these may be collectively referred to as "propylene-based copolymers") are more preferable, and ethylene-propylene copolymers are particularly preferable.

As the above-mentioned polymer, one kind may be used alone, or two or more kinds may be used in combination at any ratio. Above all, it is preferable to use a propylene-based copolymer such as an ethylene-propylene copolymer in combination with low-density polyethylene. At this time, it is particularly preferable to combine 60 to 90% by mass of the propylene-based copolymer and 40 to 10% by mass of low-density polyethylene. The higher the ethylene content, the lower the melting point of the ethylene-propylene copolymer. Therefore, from the viewpoint of ease of coextrusion and enabling low temperature extrusion, the ethylene content of comomoma is preferably in the range of 3 to 7 mol%. If it is desired to add heat resistance to the back layer, the ethylene content may be reduced and the desired heat resistance may be appropriately selected.

The melt flow rate of the propylene-based copolymer at 230 ° C. (hereinafter, may be appropriately referred to as “MFR”) is preferably in the range of 5 g / 10 minutes to 40 g / 10 minutes. In particular, those having an MFR in the range of 20 g / 10 min to 40 g / 10 min are more preferable because they can be extruded at a low temperature and the surface of the back surface layer can be easily roughened by combining with low density polyethylene.

Further, the low density polyethylene constituting the back layer preferably has an MFR of 0.5 g / 10 minutes to 5 g / 10 minutes at 190 ° C.

Further, the low density polyethylene preferably has a density of 0.910 g / cm ^{3 to} 0.929 g / cm ³ . By setting the density of the low-density polyethylene to the lower limit of this range or more, it is easy to adjust the surface roughness of the surface of the back layer to an appropriate range. Further, by setting the value to the upper limit or less, it is possible to prevent the resin from being detached from the protective film by rubbing against a roll used for transportation (for example, a metal roll, a rubber roll, etc.) and suppress the generation of white powder.

The polymer contained in the back layer (for example, a propylene-based copolymer and low-density polyethylene) may be different from the polymer contained in the adhesive layer, but it is preferable to use the same polymer.

The resin forming the back layer may contain, for example, fillers such as talc, stearic acid amide, calcium stearate, lubricants, antioxidants, ultraviolet absorbers, pigments, antistatic agents, as long as the effects of the present invention are not significantly impaired. Additives such as nucleating agents may be included. As the additive, one type may be used alone, or two or more types may be used in combination at any ratio.

The thickness of the back layer is a ratio (adhesive layer / back layer) to the thickness of the adhesive layer, and is usually 1/40 or more, preferably 1/20 or more, usually 1/1 or less, preferably 1/2 or less. Is. As a result, it is possible to prevent the thickness of the back surface layer from becoming excessively thin as compared with the adhesive layer, so that it is possible to improve the film forming property and prevent fish eyes. Further, since the thickness of the back surface layer can be prevented from becoming excessively thick as compared with the adhesive layer, the feeding tension of the protective film can be suppressed, and wrinkles and scratches at the time of bonding with the acrylic resin can be prevented.

(Middle layer)
An intermediate layer may be provided between the adhesive layer and the back surface layer, if necessary. The intermediate layer is usually formed of a resin, but it is particularly preferable that the intermediate layer is formed of a resin containing a polyolefin-based polymer.

Examples of the polyolefin-based polymer contained in the intermediate layer include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer, polypropylene, and ethylene-propylene copolymer. (Random copolymer and / or block copolymer), α-olefin-propylene copolymer, ethylene-ethyl (meth) acrylate copolymer, ethylene-methyl (meth) acrylate copolymer, ethylene-n-butyl Examples thereof include (meth) acrylate copolymers and ethylene-vinyl acetate copolymers. As the polyolefin-based polymer, one type may be used alone, or two or more types may be used in combination at any ratio. However, the polyolefin-based polymer contained in the intermediate layer is preferably a polyolefin-based polymer of a different type from the polymers contained in the pressure-sensitive adhesive layer and the back surface layer.

If necessary, the intermediate layer may contain a material for forming the adhesive layer and a material for forming the back surface layer. Normally, when a protective film is manufactured by a coextrusion molding method, a portion having a non-uniform film thickness at an end portion is slit by a slitting step or the like and removed. By using the portion removed in this way as the raw material for the intermediate layer, the amount of the raw material used can be reduced.

The intermediate layer may contain, for example, a filler such as talc, stearic acid amide, calcium stearate, a lubricant, an antioxidant, an ultraviolet absorber, a pigment, an antistatic agent, a nucleating agent, etc., as long as the effects of the present invention are not significantly impaired. Additives may be included. As the additive, one type may be used alone, or two or more types may be used in combination at any ratio.

The film thickness of the intermediate layer is usually in the range of 13 to 70 μm.

(Manufacturing method of protective film)
The protective film may be manufactured, for example, by the following manufacturing methods (i) to (iii).

(I) A method of co-extruding the material of the adhesive layer, the material of the back surface layer, and the material of the intermediate layer as needed.

(Ii) A method in which a back surface layer or an intermediate layer is prepared and an adhesive is applied to the prepared layer to form an adhesive layer.

(Iii) A method in which an adhesive layer, a back surface layer, and an intermediate layer, if necessary, are separately prepared, and the prepared layers are bonded and integrated.

Among the illustrated manufacturing methods, in the manufacturing method (i) by the coextrusion molding method, the adhesive layer and the back surface layer or the intermediate layer are firmly adhered to each other, and the adhesive residue on the acrylic resin film is unlikely to occur. It is particularly preferable because it has advantages such as low cost due to simplification. Here, the "adhesive residue" refers to a phenomenon in which the adhesive remains on the acrylic resin film after the protective film is peeled off. In the protective film produced by the production method (i), a polyolefin polymer such as branched low-density polyethylene or polyprepylene is often used as the back layer. On the other hand, for the adhesive layer, for example, vinyl acetate, linear low-density polyethylene, metallocene linear low-density polyethylene, or the like is usually used. In particular, from the viewpoint of avoiding adhesive residue and an increase in adhesive force over time, a linear low-density polyethylene-based adhesive is often used rather than a vinyl acetate-based adhesive.

Further, in the protective film manufactured by the manufacturing method (ii) by the coating method, polyethylene terephthalate and a polyolefin polymer are usually used as the back layer, and the adhesive layer is a rubber-based pressure-sensitive adhesive and an acrylic-based pressure-sensitive adhesive. Is often used. Above all, when there is concern about foreign matter in the protective film, it is preferable to use polyethylene terephthalate for the back layer rather than the polyolefin polymer. Further, in the manufacturing method (ii), a high-quality protective film without foreign matter can be obtained by manufacturing in a clean room.

In order for the surface of the protective film opposite to the acrylic resin film to have the above-mentioned arithmetic mean roughness Ra, for example, the surface of the back layer is deformed to have a predetermined arithmetic mean roughness Ra. Concavities and convexities may be formed. For example, a nip molding method in which a protective film immediately after extrusion obtained by a coextrusion molding method is pressed using a mold roll having irregularities to transfer the irregularities to the surface of the back layer; the protective film is released with irregularities. A method of peeling off the release film after pressing with a mold film to transfer the unevenness of the release film; a method of injecting fine particles onto the surface of the back layer of the protective film to cut the surface of the back layer of the protective film; Can be mentioned. Further, the step of deforming the surface of the back surface layer may be before or after the back surface layer and the adhesive layer are bonded together.

Further, unevenness may be formed on the surface of the back surface layer by adjusting the composition of the back surface layer. For example, a method in which fine particles having a predetermined particle size are contained in the back surface layer to form irregularities on the back surface layer; a method in which the mixing ratio of a material such as a resin forming the back surface layer is adjusted to form irregularities on the back surface layer, etc. Can be mentioned.

Among the above, since a protective film having no uneven transfer can be obtained in a wide width, a nip forming method using a shaped roll having unevenness is preferable, and a protective film using a mirror surface roll and a shaped roll having unevenness is preferable. The method of sandwiching the pressure is particularly preferable.

Examples of the surface material of each mirror surface roll and the shaped roll include metal, rubber, and resin. These are selected so that the desired uneven shape can be transferred to the surface of the back layer of the protective film. However, the hardness of the shaped roll is preferably equal to or higher than the hardness of the mirror surface roll. Further, for example, the protective film may be narrowed by a resin film or the like which has the same surface property as the mirror surface roll and is softer than the fixed roll.

The mirror surface roll and the shaped roll are preferably those whose temperature can be adjusted independently. The temperature of the mirror roll is preferably in the range of 40 to 160 ° C, and the temperature of the shaped roll is preferably in the range of 60 to 200 ° C. The temperature of the mirror surface roll is more preferably in the range of 60 to 130 ° C., and the temperature of the shaped roll is further preferably in the range of 80 to 180 ° C. By setting the temperature of the mirror surface roll or the shaping roll to the lower limit temperature in the above range or more, it is possible to prevent uneven transfer of unevenness. Further, by setting the temperature of the mirror surface roll or the fixed roll to be equal to or lower than the upper limit temperature in the above range, it is possible to prevent the protective film from being wound around the mirror surface roll or the fixed roll.

In the nip forming method, the above-mentioned arithmetic mean roughness Ra of the surface of the protective film opposite to the acrylic resin presses the protective film, the mirror surface roll and the shaping roll temperature, the roll speed, and the protective film at the time of pinching. The pressure at the time and the surface material of the mirror surface roll and the shaping roll can be adjusted by appropriately selecting them according to the characteristics of the material forming the protective film. Usually, the mirror surface roll and the shaped roll temperature are preferably (Tg-60) to (Tg + 20) ° C. with respect to the glass transition temperature (Tg) of the resin forming the back surface layer.

The surface of the protective film may be subjected to a surface modification treatment, if necessary. Examples of the surface modification treatment include energy ray irradiation treatment and chemical treatment.

Further, printing may be performed on the surface of the protective film, if necessary.

(Paste)
A multi-layer film is obtained by laminating an acrylic resin film and a protective film. At the time of bonding, it is preferable to apply a predetermined amount of tension to the acrylic resin film and the protective film in order to eliminate wrinkles and slack in the acrylic resin film and the protective film. Further, at the time of bonding, it is preferable to perform bonding while applying pressure, for example, by using a nip roll or the like.

The multilayer film thus produced includes an acrylic resin film and a protective film. Further, in the multilayer film, the acrylic resin film is usually exposed on one surface, and the protective film is exposed on the other surface. At this time, an arbitrary layer may be further provided between the acrylic resin film and the protective film. The arbitrary layer may be one layer or two or more layers. Further, when there are two or more arbitrary layers, these layers may be the same or different.

The width of the multilayer film is preferably 1500 mm or more, more preferably 1800 mm or more. In general, a film roll wound with a wide film is prone to wrinkles or gauge bands. However, the multi-layer film according to the present embodiment can realize a good winding shape when wound while having such a wide width. Further, the upper limit of the width of the multilayer film is usually 2500 mm or less.

(Process of winding the multi-layer film)
After obtaining the multi-layer film, the multi-layer film is wound into a roll to obtain an acrylic resin film roll. Usually, in the step of winding the multilayer film, a winding device including a winding roll and a pressure contact roller is used. Then, the acrylic resin film roll is obtained by winding the multilayer film on the winding roll while applying surface pressure to the multilayer film by pressing with a pressure contact roller.

By winding the multi-layer film while applying surface pressure with a pressure contact roller, it is easy to suppress the amount of air entrained in the winding at high speed. Therefore, it is possible to prevent the occurrence of wrinkles and manufacture an acrylic resin film roll having a good winding shape.

At this time, when the arithmetic average roughness of the surface of the protective film opposite to the acrylic resin film is Ra (μm), the pressure P (N / m) of the contact pressure roller is the following formula (4-1). It is preferable to satisfy.

50 × Ra + 75 ≦ P ≦ 23 × Ra + 160 (4-1)
As described above, from the viewpoint of preventing wrinkles and gauge bands when winding the multilayer film, it is preferable to suppress and control the amount of air entrained between the laminated multilayer films. At this time, the amount of air entrained varies depending on the surface roughness of the surface of the protective film opposite to the acrylic resin film. Therefore, it is preferable to set the pressure P of the pressure contact roller according to the surface roughness of the surface of the protective film opposite to the acrylic resin film.

The rougher the surface roughness of the surface of the protective film opposite to the acrylic resin film, the larger the amount of air entrained during winding. Therefore, increase the pressure P of the pressure contact roller to entrain air. It is preferable to suppress. Further, if the surface roughness of the surface of the protective film opposite to that of the acrylic resin film is rough, the amount of air entrained during winding increases, so that the amount of air entrained due to the change in the pressure P of the pressure contact roller The change will also be large. Therefore, when the surface roughness of the surface opposite to the acrylic resin film of the protective film is rough as compared with the case where the surface roughness of the surface opposite to the acrylic resin film of the protective film is smooth. , The suitable range of the pressure P of the pressure contact roller is narrowed. Therefore, the pressure P of the pressure contact roller is in the range of the arithmetic average roughness Ra of the surface opposite to the acrylic resin film of the protective film, in the range corresponding to the Ra as in the above formula (4-1). It is preferable to have.

The winding speed of the multilayer film is usually 5 m / min or more, preferably 10 m / min or more, usually 50 m / min or less, preferably 45 m / min or less, and more preferably 40 m / min or less. The manufacturing efficiency can be improved by setting the winding speed to be equal to or higher than the lower limit of the above range, and the amount of air entrainment can be suppressed by setting the winding speed to be equal to or lower than the upper limit.

The number of turns of the acrylic resin film roll is not limited, but is usually 40 times or more, preferably 60 times or more, and usually 27,000 times or less, preferably 13,000 times or less.

The outer diameter of the acrylic resin film roll is not limited, but is usually 160 mm or more, preferably 190 mm or more, and usually 2300 mm or less, preferably 1200 mm or less.

A packaging method for an acrylic resin film roll (roll-shaped film) and a preferred embodiment of a package according to the present invention will be described.

FIG. 14 is a perspective view showing a roll-shaped film and a packaging material, and FIG. 15 is a perspective view showing a package in which the roll-shaped film is wrapped in the packaging material.

As shown in FIG. 14, the roll-shaped film 712 has a cylindrical winding core 716, and a long film 714 is wound around the winding core 716 in a roll shape. The width dimension of the winding core 716 is formed to be larger than the width dimension of the film 714, and the film 714 is wound at a substantially central position in the width direction of the winding core 716. Therefore, in the roll-shaped film 712, both ends of the winding core 716 are in a state of protruding from the film 714.

The film 714 is provided with at least one photocurable resin layer on its surface, as will be described later.

Further, the film 714 has minute irregularities, which are also called embossing or knurling, at both end positions in the width direction, and for the purpose of preventing end face misalignment and loosening when winding the film into a roll shape, for example, high height. It is formed in the range of 5 to 50 μm or in the range of 0.05 to 0.3 of the film thickness.

On the other hand, the packaging material 718 is formed in a cylindrical shape, and its width dimension is larger than the width dimension of the film 714. The inner diameter of the packaging material 718 is formed to be larger than the outer diameter of the roll-shaped film 712, so that the roll-shaped film 712 can be covered with the packaging material 718. The packaging material 718 may be a rectangular sheet, and in this case, the roll-shaped film 712 is wrapped with the packaging material 718 to form a cylinder, and then the edge of the packaging material 718 is attached with an adhesive tape or the like. It is good to paste and fix it with.

As the packaging material 718, a material having an outer surface having a solar reflectance of 70% or more (JIS-R-3106 compliant) is used. For example, a packaging material 718 in which aluminum is vapor-deposited on the outer surface of polyethylene (PET) is used. The packaging material 718 may have a solar reflectance of 70% or more, and may be a metal-deposited material other than aluminum or a metal foil such as aluminum foil. Further, the solar reflectance of the packaging material 718 is more preferably 80% or more, further preferably 90% or more. By forming the package 710 of FIG. 15 using such a packaging material 718, the temperature difference inside the package 710 can be suppressed within 25 ° C, preferably within 20 ° C.

Further, it is preferable to use a packaging material 718 having a moisture permeability of 5.4 g / m ^{2 · day or less in a 40 ° C. 90% RH environment.} By using such a moisture-permeable packaging material 718, the humidity change rate inside the package 710 can be suppressed to 4% / min or less.

As shown in FIG. 15, the packaging material 718 configured as described above is covered with a roll-shaped film 712, and rubber bands 720 are externally fitted to both ends thereof. Both ends of the packaging material 718 are fixed by the rubber band 720 in a state of being in close contact with the outer peripheral surface of the winding core 716. As a result, the packaging body 710 in which the roll-shaped film 712 is wrapped with the packaging material 718 is formed. The method of fixing the packaging material 718 is not limited to the rubber band 720, and the packaging material 718 may be fixed by sticking it to the winding core 716 with an adhesive tape or the like.

Next, the operation of the package 710 configured as described above will be described. 16 (A) and 16 (B) are schematic views illustrating a failure of the roll-shaped film 712 in a conventional package (that is, a package packaged with a packaging material having a solar reflectance of less than 70%). ..

In the case of a conventional package, when sunlight hits the package, a temperature difference occurs between the hit side and the non-hit side inside the package, and a humidity difference due to the temperature difference occurs. As a result, a difference in thermal expansion or a difference in humidity expansion of the film 714 occurs between the two, and deformation of the roll-shaped film 712 called a beco failure occurs. As shown in FIG. 16B, the beco failure means that the end portion of the film 714 in the width direction is firmly wound by the knurl (emboss) 714A, whereas the central portion is deformed due to the loose winding. This is a phenomenon, and the higher the tension during winding, the more likely it is to occur. For this reason, conventionally, it is not possible to increase the take-up tension in the processing apparatus at the previous stage, and it is not possible to cope with the increase in length of the film 714 and the increase in the transfer speed.

On the other hand, the package of the present embodiment is packaged with a packaging material 718 having a solar reflectance of 70% or more. Therefore, even when sunlight hits the package 710, most of the sunlight is reflected by the packaging material 718 and is not absorbed by the package 710, so that a temperature difference and a humidity difference occur inside the package 710. Can be prevented. As a result, it is possible to prevent the film 714 from being deformed and causing a beco failure, and it is possible to prevent a defect in the package 710 even in the case of the roll-shaped film 714 having a high take-up tension. Therefore, according to the present embodiment, since the winding tension can be increased in the processing line before packaging, it is possible to lengthen the film 714 and increase the transport speed.

Further, when the acrylic resin film is wound around the winding core, a double-sided tape, a cushioning material, or the like is attached to the winding core. The double-sided tape is for fixing the tip of the film to the winding core.

As shown in FIG. 17, in the double-sided tape 831, for example, the first adhesive layer 831b on the winding core side is on one surface (back surface) of the strip-shaped support 831a made of PET (polyethylene terephthalate) on the other surface (front surface). The second adhesive layer 831c on the film side is formed. The thickness t02 of the double-sided tape 831 is in the range of 10 to 60 μm, preferably in the range of 10 to 30 μm, and more preferably in the range of 10 to 15 μm. As the double-sided tape 831, for example, Nitto Denko (models: 5601, 5603, 5605, 5606) is used. In each cross-sectional view after FIG. 17, it is difficult to distinguish each member such as the film 815, the double-sided tape 831 and the cushioning material 832 when the actual dimensions are displayed. Therefore, the dimensions in the thickness direction are exaggerated in each drawing. Is displayed.

The width W02 of the double-sided tape 831 is in the range of 25 to 150 mm, preferably in the range of 40 to 90 mm, and more preferably in the range of 40 to 60 mm. If it is less than 25 mm, sticking is poor, and if it exceeds 150 mm, wrinkles are likely to occur on the tape, both of which are not preferable.

Each of the adhesive layers 831b and 831c of the double-sided tape 831 is formed on the entire surface of the support 831a. Each of these adhesive layers 831b and 831c has the same composition and thickness, but may have a different composition or a different thickness. Although not shown, a release tape is attached to the forming surface of the second adhesive layer 831c. The release tape is peeled off after the double-sided tape 831 is attached to the winding core 823 by the first adhesive layer 831b and before the film 815 is wound up.

The cushioning material 832 is made of, for example, polyester, a non-woven fabric, or the like, and is formed to be thinner than the thickness of the film 815 to be wound. Then, a tape having more elasticity than the double-sided tape 831 is used. The cushioning material 832 does not have to have an adhesive layer by itself, and in this case, it is attached to the winding core 823 via the double-sided tape 831.

As shown in FIG. 18, the width W03 of the cushioning material 832 is in the range of 5 to 30 mm, preferably in the range of 8 to 18 mm, and more preferably in the range of 8 to 12 mm. If it is less than 5 mm, poor bonding to the winding core occurs, and if it exceeds 30 mm, the cut-off image cannot be improved, which is not preferable. When the width W03 of the cushioning material 832 is determined based on the circumference of the winding core, it is preferably 2% or less of the circumference of the winding core.

As shown in FIG. 18, the thickness t03 of the cushioning material 832 depends on the quantity of the cushioning material used. For example, as shown in FIGS. 18 to 21 and FIG. 23 described later, when one cushioning material 832 and 833 is used, the thickness is in the range of 10 to 90% of the thickness of the film 815, preferably 25 to 75%. The range, more preferably the range of 35-65%. When the thickness of the cushioning material 832 is less than 10% or more than 90% of the thickness of the film 815, the effect of improving the cut-off image is reduced. When there are a plurality of cushioning materials 814 to 844, the thickness may be gradually reduced from the cushioning materials 814 to 844 close to the film tip 815a. In this case, it is desirable that the difference in the thickness of each cushioning material 814 to 844 is suppressed to 5% or more and 30% or less of the thickness of the film 815.

In the case of the cushioning material 833 having the adhesive layer 833b on at least one surface of the cushioning material main body 833a as in the second embodiment shown in FIG. 20, the cushioning material 833 is directly attached to the winding core 823 without using the double-sided tape 831. It is pasted on. In each of the following embodiments, the same components are designated by the same reference numerals and duplicated description is omitted.

21 and 22 show the third embodiment, in which two types of cushioning materials 841 and 842 having different thicknesses are arranged side by side in the winding direction of the film 815. The first cushioning material 841 close to the tip 815a of the film 815 and the second cushioning material 842 far from the tip 815a both have a thickness t12 and t22 equal to or less than the thickness t01 of the polymer film 15, and t12> t22. Further, the widths W12 and W22 of the first cushioning material 841 and the second cushioning material 842 are in the range of 0.5 to 6.0% of the circumferential length of the winding core.

In the third embodiment, since the thicknesses t21 and t22 of the first cushioning material 841 and the second cushioning material 842 are changed in two steps, the bending deformation of the step mark is changed in two steps as compared with that of the first embodiment. The length of the step trace can be made smaller than that of the cushioning material 832 of the first embodiment.

In the fourth embodiment, instead of the third embodiment shown in FIGS. 21 and 22, as shown in FIG. 23, the cushioning material 843 having the adhesive layers 843b and 844b on at least one surface of the cushioning material main bodies 843a and 844a. , 844 are used. In this case, the cushioning materials 843 and 844 are directly attached to the winding core 823 without using the double-sided tape 831.

Instead of changing the thicknesses t12 and t22 of the cushioning materials 814 to 844, the elastic modulus (Young ratio) of the cushioning materials 814 to 844 can be changed, or the elastic modulus (Young) can be changed together with the thickness of the cushioning materials 814 to 844. The rate) may be changed so that the amount of compression deformation of the second cushioning materials 842 and 844 away from the film tip 815a is larger than the amount of compression deformation of the first cushioning materials 841 and 843. In this case, the two cushioning materials suppress the generation of a step due to the influence of the tip of the film, and can further suppress the cut-off image.

The relationship between the elastic modulus and the thickness of the cushioning materials 832, 833, 841-844 is preferably changed according to the elastic modulus of the film to be wound 815. For example, when the elastic modulus of the film 815 is Ep and the elastic modulus of the cushioning material is Eb, when Ep ≦ Eb, the thickness of the film is tp, and the thickness of the cushioning material is tb (tp). / 2) <tb <tp. When Ep> Eb, tp <tb <2 · tp.

As shown in FIGS. 17 and 18, the gap G01 from the film tip 815a to the cushioning material 832 is in the range of 0.1 to 20 mm, preferably in the range of 0.1 to 10 mm, and more preferably 0.1. The range is ~ 8 mm. If it is less than 0.1 mm, the film 815 tends to overlap with the cushioning material 832, and if it exceeds 20 mm, a step is generated between the film tip 815a and the cushioning material 832, which causes a cut edge image, which is not preferable.

As shown in FIG. 19, when the film 815 is wound around the winding core 823 and the next film 815 is overlapped with the film tip 815a, the cushioning material 832 alleviates the influence of the step of the next wound film 815. As a result, extreme bending does not occur in the film 815. Hereinafter, the next film is wound in the same manner, but in each case, extreme bending deformation does not occur due to the influence of the cushioning material 832, and the occurrence of cut-off image is suppressed.

The double-sided tape 831 may be attached or the film tip may be adhered by the double-sided tape 831 manually or by using a film cutting device. In the case of manual operation, a film reservoir (not shown) is provided immediately before the winding device 813. This film reservoir temporarily stores the film 815 for the time required for cutting the film 815 and fixing it to the winding core 823, and during this storage, the film 815 is cut and wound around the winding core 823. .. In the case of automatic operation, the film 815 is cut and fixed to the winding core 823 by using a film cutting device. In this case, the position of the double-sided tape 831 on the winding core 823 is automatically detected, the film 815 is cut based on this detection timing, and the cut film tip 815a becomes a predetermined gap G01 with respect to the cushioning material 832. As described above, the tip of the film is bonded to the second adhesive layer 831c.

The double-sided tape 831 and the cushioning materials 832, 833, 841-844 were attached to the winding core 823 in advance, but on the film cutting device side, the double-sided tape 831, the cushioning materials 832, 833, 841- were attached to the film cutting drum. Even if 844 is attached and the double-sided tape 831 and the cushioning materials 832, 833, 841-844 are attached to the winding core 823 together with the film 815 when the film 815 is cut by the film cutting drum, the film 815 is wound up. good.

As shown in FIGS. 21 to 23, instead of changing the elastic modulus and thickness of the two cushioning materials 841-844, although not shown, the first end on the side closer to the film tip 815a with respect to one cushioning material. The thickness may be gradually reduced toward the second edge on the side far from the edge. In this case as well, the film to be wound next by the cushioning material does not undergo extreme bending deformation, and the occurrence of cut-off image can be suppressed.

As shown in FIG. 24, the inclination angle θ1 of the film tip 815a with respect to the film width direction reference line BL1 is preferably in the range of −30 ° <θ1 <30 °, more preferably in the range of −20 ° <θ1 <20 °. , More preferably in the range of −10 ° <θ1 <10 °. The closer the inclination angle θ1 is to 0 °, the smaller the stress due to the influence of the film surface pressure that is superimposed on the film tip 815a thereafter, and thus the cut-off image can be suppressed. In this way, when the tip 815a of the film 815 is cut at a predetermined tilt angle θ1, the double-sided tape 831 and the cushioning materials 832, 833, 841-844 also have the same tilt angle according to the tilt angle θ1 of the film tip 815a. Attach it to the winding core 823 with θ1.

The width of the film 815 is not particularly limited, but is preferably 600 mm or more, and more preferably in the range of 1100 to 2500 mm. It is also effective when the width of the film 815 is larger than 2500 mm. The thickness of the film 815 is preferably in the range of 10 to 200 μm, more preferably in the range of 10 to 150 μm, and even more preferably in the range of 15 to 100 μm. The length of the film 815 is preferably 2000 m or more, and more preferably 2500 to 10000 m. The winding radius of the film roll is preferably 450 mm or more, more preferably 650 to 920 mm.

As shown in FIG. 18, the length L2 of the double-sided tape 831 in the tubular center direction of the winding core 823 is not particularly limited, but L2 = (W01-0) mm to that of the width W01 of the film 815. (W01-10) mm is preferable.

The winding core used for winding the acrylic resin film according to the present invention preferably satisfies the following formula (1).

E> 0.06 x Aa ³ / I (1)
(E: Elastic modulus of the take-up core [MPa], A: Total mass of the take-up core and the film [kg], a: Width of the resin film [mm], I: Second moment of inertia of area of the take-up core [mm] ⁴ ])
According to the above configuration, the winding core used in the winding process of winding the film around the winding core in a roll shape has an elastic modulus capable of suppressing bending according to the width and winding length of the film to be wound. Is. Therefore, a film roll that can suppress the occurrence of back deformation of the horse even if left for a long period of time can be obtained. Therefore, the obtained film roll can be used as a film in which sticking between the films due to the deformation of the back of the horse is suppressed.

By using the acrylic resin film according to the present invention, it is possible to obtain a film roll having a uniform film thickness and capable of feeding out and supplying a film in which sticking of resin films to each other due to back deformation of a horse is suppressed.

The present inventor speculates that the back deformation of the horse on the film roll in which the film is wound around the winding core may be caused by the bending of the winding core due to the load of the wound film or the winding core. ..

Therefore, the deflection ν of the take-up core will be described below.

The deflection ν of the take-up core is generally expressed by the following equation (2) because the take-up core is supported and held at both ends of the take-up core.

ν = 5ωa ⁴ /384EI (2)
(Ν: Deflection of the take-up core [mm], ω: Load per unit length of the take-up core [N / mm], a: Width of the resin film [mm], E: Elastic modulus of the take-up core [MPa] ], I: Moment of inertia of area of the take-up core [mm ⁴ ])
In the above formula (2), the load ω per unit length of the take-up core is generally expressed by the following formula (3) because the load applied to the take-up core is a distributed load.

ω = P / a (3)
(Ω: load per unit length of the take-up core [N / mm], P: load of the take-up core [N], a: width of the resin film [mm])
Therefore, the deflection ν of the take-up core is expressed by the following equation (4).

ν = ^{5Pa 3} /384EI (4)
(Ν: Deflection of the winding core [mm], P: Load of the winding core [N], a: Width of the resin film [mm], E: Elastic modulus of the winding core [MPa], I: Winding core Second moment of area [mm ⁴ ])
Next, the present inventor focused on the fact that the deflection of the winding core differs depending on the difference in the load based on the width, winding length, etc. of the resin film.

Therefore, first, since the load P of the winding core here is a value that correlates with the total mass A of the winding core and the resin film in the state where the resin film is wound, the load P is the total mass A. Replaced with. Then, as a result of diligently examining the conditions under which the occurrence of back deformation of the horse can be sufficiently suppressed, the relationship of the above equation (1) was found.

Therefore, by satisfying the relationship of the above formula (1), the elastic modulus of the take-up core is an elastic modulus that can suppress the deflection according to the width, the winding length, and the like of the resin film to be taken up. Therefore, even if the resin film is wound into a roll and left for a long period of time, the occurrence of back deformation of the horse can be suppressed.

Further, in the present embodiment, the elastic modulus of the winding core is defined by the total mass A of the winding core and the resin film, the width a of the resin film, and the moment of inertia of area I of the winding core, as described above. Therefore, it mainly depends on the width and winding length of the resin film to be wound. Therefore, the elastic modulus of the winding core can be set so as to sufficiently suppress the occurrence of back deformation of the horse based on the width and winding length of the resin film to be wound. Therefore, it is preferable because the occurrence of back deformation of the horse can be sufficiently suppressed without incurring an unnecessarily high manufacturing cost of the take-up core. The moment of inertia of area of the take-up core is generally a value represented by the following equation (5). As can be seen from the following equation (5), the moment of inertia of area is a value that depends on the shape of the take-up core.

I = (d2 ^{4 −} d1 ⁴ ) × π / 64 (5)
(D1: Inner diameter of the take-up core [mm], d2: Outer diameter of the take-up core [mm])
The take-up core may have an elastic modulus within the above range, and is not particularly limited to a material or the like. For example, it may be made of resin or metal. Among them, those provided with a fiber reinforced plastic (FRP) layer containing the resin and the fiber are preferable. Since the fiber-reinforced resin layer is a resin layer reinforced by fibers, the elastic modulus can be easily adjusted depending on the strength and content of the fibers contained therein. Therefore, the elastic modulus of the take-up core can be easily adjusted within the above range. The take-up core 11 provided with such a fiber-reinforced resin layer may be, for example, one composed of only one fiber-reinforced resin layer, or two layers of different fiber-reinforced resin layers laminated. It may be present, or it may be a stack of three or more different fiber reinforced resin layers. Further, a fiber-reinforced resin layer and a fiber-free resin layer may be laminated.

Further, the shape of the take-up core is preferably a cylindrical shape. If the elastic modulus of the take-up core is within the above range, a cylindrical shape having a hollow inside is preferable because it can reduce the weight. It is also preferable because it is easy to attach the take-up core to the rotating device. When the shape of the take-up core is cylindrical, the thickness of the take-up core varies depending on the elastic modulus of the take-up core, but is preferably in the range of, for example, 5 to 15 mm.

Next, a method for manufacturing a take-up core provided with the fiber-reinforced resin layer as described above will be described. The method for manufacturing the winding core is not particularly limited, but can be manufactured by, for example, a filament winding method, a sheet winding method, or the like. The filament winding method is a method in which filament-like fibers impregnated with a liquid resin are wound around a predetermined mold, the resin is dried or cured, and then the mold is removed to form a cylindrical fiber-reinforced resin layer. .. In the sheet winding method, a sheet-shaped fiber (prepreg) impregnated with a liquid resin is wound around a predetermined mold, the resin is dried or cured, and then the mold is removed to form a cylindrical fiber-reinforced resin layer. Is a method of forming. More specifically, the method is as follows.

FIG. 25 is a schematic diagram for explaining a method of manufacturing a winding core by a filament winding method. First, the mandrel 931 to be a mold is attached to the filament winder 932, and the resin which is the raw material of the fiber reinforced resin layer is put into the resin tank 933. The resin here is a resin solution or a liquid resin before curing. The fibers, which are the raw materials of the fiber-reinforced resin layer, are sequentially supplied from the roller 934 around which the fibers are wound by rotating the mandrel 931 with the filament winder 932. Then, the fiber is wound around the mandrel 931 at a position to be wound by the guide 935. At that time, the fiber passes through the resin tank 933 and is impregnated with the resin before being wound around the mandrel 931. By doing so, the resin-impregnated fibers are wrapped around the surface of the mandrel. Then, the resin is dried or cured to form a fiber-reinforced resin layer on the mandrel. Then, by pulling out the mandrel from the fiber reinforced resin layer, a desired molded product is obtained.

FIG. 26 is a schematic diagram for explaining a method of manufacturing a winding core by a sheet winding method. First, the mandrel 941 which is a mold is placed on the support rollers 944 and 945. The mandrel 941 is rotated by rotationally driving the support rollers 944 and 945. At that time, the touch roller 943 presses the surface of the mandrel 941 and is driven to rotate by the rotation of the mandrel 941. Then, by rotating the mandrel 941 which is a mold, as shown in FIG. 26, the film roll (prepreg) 942 is wound on the mandrel 941 while being pressed against the mandrel 941 by the touch roller 943. Then, the resin is dried or cured to form a fiber-reinforced resin layer on the mandrel. Then, by pulling out the mandrel from the fiber reinforced resin layer, a desired molded product is obtained.

As the fiber, for example, any form of fiber material such as yarn, roving, woven fabric, non-woven fabric, knitted fabric, braid, cloth and the like can be used. Further, as the material, any fiber generally contained in the fiber reinforced resin can be used without particular limitation. For example, glass fiber, carbon fiber, aramid fiber, ceramic fiber and the like can be mentioned. Among these, glass fibers and carbon fibers are preferable, and carbon fibers are more preferable, because those having a high elastic modulus can be obtained.

Further, as the resin, any resin generally contained in the fiber reinforced resin can be used without particular limitation. For example, polyester resin, unsaturated polyester resin, epoxy resin and the like can be mentioned. Among these, a curable resin such as an unsaturated polyester resin or an epoxy resin is preferable because a winding core that is stable against heat can be obtained.

Further, when two or more fiber reinforced layers are laminated, for example, when two different fiber reinforced resin layers are laminated, different fibers and resins may be used for each layer, or the same one may be used. You may. Further, two or more fibers impregnated with the resin may be wound and then dried or cured at the same time to form two or more fiber reinforcing layers, or the fibers impregnated with the resin may be wound and dried or cured. Later, two or more fiber reinforcing layers may be formed by winding a fiber impregnated with a resin separately and drying or curing the fiber.

The method for adjusting the elastic modulus of the take-up core is not particularly limited, but it can be adjusted by changing the material of the take-up core. Further, in the case of a winding core provided with a fiber reinforced layer, high-strength fibers such as carbon fiber and aramid fiber are used as the fibers to be used, the winding amount is increased, and the fiber content is increased. The elastic modulus can be increased. The elastic modulus can also be adjusted by using a resin. Further, in the case where the fiber-free resin layer is laminated on the surface of the fiber-reinforced resin layer, the elastic modulus can also be adjusted by the resin of the surface resin layer. Therefore, the elastic modulus of the winding core can be adjusted within the elastic modulus range by appropriately adjusting the composition of the fiber-reinforced resin layer and the resin layer on the surface layer.

(6) Slit Step In the method for manufacturing an acrylic resin film of the present invention, it is preferable to adopt a manufacturing device in which the number of slit devices installed at one end of the film is 1 to 3 per one end of the film.

In the manufacturing apparatus for manufacturing the acrylic resin film according to the present invention, it is preferable that the film slit device is composed of a disk-shaped rotary upper blade and a roll-shaped rotary lower blade.

Here, the disk-shaped rotary upper blade of the slit device has a diameter in the range of 30 to 300 mm and a cutting portion in the thickness of 0.3 to 3 mm, and the material of the rotary upper blade is super steel or super. It is either fine steel, SKD (alloy tool steel), or SKH (high speed tool steel). Further, it is preferable that the toe-in angle of the upper blade is in the range of 30 to 90 degrees.

The roll-shaped rotary lower blade has a roll diameter in the range of 75 to 200 mm, and the roll material of the rotary lower blade is any one of super steel, super steel fine particles, SKD, and SKH.

In the manufacturing apparatus, the film slit apparatus may be composed of only a disk-shaped rotary upper blade. In this case, the disk-shaped rotary upper blade of the slit device has a diameter in the range of 30 to 300 mm and a cutting portion in the thickness of 0.3 to 3 mm, and the material of the rotary upper blade is super steel or super. It is either steel granules, SKD, or SKH.

In the present invention, it is preferable that the temperature around the slitter is in the range of 20 to 50 ° C. and the humidity is in the range of 50 to 70% RH.

Further, in the present invention, it is preferable to provide a suction device in which the periphery of the upper blade is boxed and suction is performed in a wind speed range of 0.8 to 10 m / sec. In this case, the suction position of the end film is on the downstream side in the base transport direction from the slitting point.

In the present invention, it is preferable to provide a mechanism for transporting the slit end film (film fragment) to the next cutting step, for example, providing a mechanism for niping and / or sucking the slit end film. However, it is preferable. Further, it is preferable to provide a mechanism for niping and / or winding the slit end film.

Here, it is preferable that the draw ratio, that is, the speed of the nip and / or the film to be wound divided by the speed of the slit end film is in the range of 0.8 to 1.5.

Further, it is preferable that the suction pressure is in the range of −1000 to −100 Pa. The nip pressure is preferably in the range of 0.1 to 17 MPa.

In the production of the acrylic resin film according to the present invention, the width of the slit end film is in the range of 20 to 150 mm, and the thickness is in the range of 30 to 150 μm.

In the present invention, there is also a method of slitting the conveyed film after covering it with a masking base.

The masking-based material is not particularly limited as long as it can protect the film, and examples thereof include polyethylene terephthalate (PET) film, polyethylene (PE) film, and polypropylene (PP) film.

Further, it is preferable that the amount of charge of the slit end film is in the range of 0 to ± 10 kV. Therefore, it is preferable to provide a static elimination device around the upper blade, and as the static elimination device, for example, any of a static elimination bar, a static elimination blower, and a static elimination thread is used.

The slit end film (film fragment) is preferably treated with an edge cleaner.

Further, it is preferable that the end portion of the product film after slitting is treated with a web cleaner to remove chips.

In the production method of the present invention, it is also preferable to take a heating step of heating the formed film in a heating unit.

In this heating step, the film thickness is first measured with an in-line film thickness meter. Thereby, for example, the film thickness formed so that both ends in the width direction are thicker than the inside is measured. The thickening of the film thickness at both ends in the width direction is caused by the action of a pulling force toward the center of the width when the resin is pushed out from the slit of the T-die, which is a so-called neck-in phenomenon. It is due to.

Then, the film whose film thickness has been measured is heated with a heat gun. At this time, the control unit calculates the average film thickness t in the range of 10% of the total width from both ends in the width direction of the film based on the measurement result of the film thickness, and within this range, the average film thickness t or less. It is preferable that the heat gun is set so as to heat at least a part of the film portion H having the film thickness of. At the same time, the output of the heat gun is adjusted so that the temperature T of at least a part of the film portion H to be heated becomes 80 ≦ T ≦ Tg + 50 [° C.] (Tg: glass transition temperature [° C.] of the resin).

This heating is for relieving the stress generated at both ends of the film by thermal deformation. More specifically, the force that pulls the film toward the center of the width (of the film) as a result of the transfer tension being concentrated at both ends of the film formed to be thicker by the above-mentioned neck-in phenomenon during transfer by a plurality of rollers. The force that narrows the width) acts to generate stress. The above heating is for relieving this stress. As a result, it is possible to suppress the occurrence of vertical wrinkles in the longitudinal direction (transportation direction) due to this stress and minute strains that cannot be visually confirmed. This effect is more remarkable in the step of transporting the unstretched film for a long time due to the above-mentioned stress generation factor.

Further, this heating is preferable because it is possible to effectively suppress the occurrence of the above-mentioned vertical wrinkles and strain by performing this heating before the stretching step in addition to the slit step. This is because vertical wrinkles and strains are emphasized by stretching the film in the longitudinal direction in the stretching step. Furthermore, it is desirable that this heating be performed immediately after the resin is cooled and solidified by the cooling roller.

Further, when the temperature T of the film due to this heating is less than 80 ° C., the thermal deformation of the film F is small and the effect of relaxing the stress is insufficient, and when it is higher than Tg + 50 ° C., the heated portion of the film F is located. It may melt and the film may adhere to the rollers or break in the transport direction. Therefore, by setting this temperature T to 80 ≦ T ≦ Tg + 50 [° C.], the film can be sufficiently thermally deformed while preventing melting of the heated portion. However, this temperature T is more preferably 80 ≦ T ≦ Tg + 30 [° C.], and even more preferably 100 ≦ T ≦ Tg + 10 [° C.].

Next, at least a part of the heated film portion H is cut and removed (cutting step).

More specifically, the portion from the heated portion of the film portion H to the end portion of the film is removed by cutting in the longitudinal direction of the film with a rotary cutter of the heating portion. By removing both ends of the film in this cutting step, it is possible to prevent the generation of stress at both ends due to subsequent transportation, so that the occurrence of vertical wrinkles and strain can be more reliably suppressed. In this cutting step, only the heated portion of the film portion H may be removed, or the entire film portion H may be removed. Further, it is not necessary to perform this cutting step.

Next, the molded and heated film is stretched in the longitudinal direction with a longitudinal stretching machine (stretching step).

In this stretching step, the film is stretched in the longitudinal direction (conveying direction) by transporting the film with a plurality of rollers driven in order to gradually increase the peripheral speed while heating the film F with an IR heater. do. At this time, the rollers are driven so that the difference in peripheral speed between the rollers on which the film is heated by the IR heater is the largest.

Next, the stretched film is wound up with a winder in the winding section.

According to the above manufacturing method, since at least a part of the film before being stretched in the longitudinal direction is heated from both ends in the width direction of the film within a predetermined range, vertical wrinkles and strains in the longitudinal direction are stretched. Before being emphasized by, the portion where a stronger transport tension is applied than the inside in the width direction can be thermally deformed to effectively relieve the stress that causes vertical wrinkles and strain.

At this time, since at least a part of the film is heated within a width range of 10% of the total width from both ends in the width direction of the film, the entire film is heated, causing unnecessary stretching and changes in optical characteristics due to the transport tension. The effective width of the finished acrylic resin film is not reduced due to vertical wrinkles and distortion on the inside of the film outside the above range.

Further, since only at least a part of the film portion H having a film thickness equal to or less than the average film thickness t in the above range is heated, that is, the end portion of the film F which is formed to be the thickest and has the strongest transport tension acts on it. Do not heat. This makes it possible to prevent the film F from breaking due to the end portion being heated and the film F being partially stretched.

Further, since at least a part of the film portion H is heated to a temperature T satisfying 80 ≦ T ≦ Tg + 50 [° C.] (Tg: glass transition temperature [° C.] of acrylic resin R), melting of the heated portion is prevented. It can be sufficiently thermally deformed to surely relieve the stress that causes vertical wrinkles and strain.

As a result, it is possible to suppress the occurrence of vertical wrinkles and distortion in the longitudinal direction.

Further, although the film is stretched only in the longitudinal direction (transportation direction) in the stretching step, a tenter may be provided in the wake of the longitudinal stretching machine and the film may be stretched in the width direction by the tenter.

The in-line film thickness meter may be of either contact type or non-contact type, but it is a non-contact type using a laser or X-ray because it is easy to measure in the line. It is preferable to do.

Further, the heat gun does not have to heat the film with hot air, and may be heated while in contact with a heat roller or the like, or may be heated by irradiation with an IR heater or the like.

Further, the rotary cutter does not have to be a rotary type, and may be a fixed type such as a single-edged cutter.

In the method for producing an acrylic resin film of the present invention, a laser processing step (a step of irradiating a laser beam to process a film, which may be simply referred to as laser processing) is preferably adopted in the slitting step. There is little damage to the film such as melting of the cut portion and poor appearance of the cut portion, and even if the laser intensity fluctuates slightly, the shape of the cut portion is not disturbed. Further, the step of forming the unevenness on both ends in the width direction of the film can be changed to the step of processing by laser irradiation instead of the conventional step of processing with the embossing roller forming the unevenness, and the predetermined uneven shape is good. Can be formed into. In addition, even if the film film thickness specification changes, there is no need to replace it with an embossed roller that corresponds to the film film thickness as in the past, excessive laser intensity is not required, and there is little damage to the film such as damage to uneven parts. Further, by adjusting the intensity of the laser beam, appropriate embossing can be easily performed, so that the film productivity is excellent. Further, it is preferable that the irradiation position of the laser beam is variable and the embossed portion is formed at a predetermined position according to the film width. In this way, by making the irradiation position of the laser beam variable, it becomes possible to easily form the unevenness of the embossed portion on either the edge portion or the central portion in the width direction of the film, and the conventional embossing can be performed. During processing, the film surface can be dramatically improved in surface quality by eliminating defects such as minute wrinkles and scratches on the film surface caused by contacting the back roller with the embossing roller for pressing.

Further, the laser processing step is not limited to the cutting process and the embossing process as described above, but may be laser processing performed during the film manufacturing process. For example, in order to improve the transportability, the end portion of the film may be used. Laser processing such as processing for roughening the surface or processing for providing grooves and irregularities may be used.

Further, in the present invention, when the laser light in the laser processing step is light in the far infrared region, the compound contained in the film is a compound that absorbs light in the wavelength region of 4 to 25 μm. For example, when the laser light is a CO ₂ laser, the wavelength of the laser light is 9.3 to 10.6 μm, so a compound that absorbs a wavelength in this range is preferable.

Further, in the present invention, when the laser light in the laser processing step is UV light in the ultraviolet region, the compound contained in the film or coated on the film surface has a wavelength region of 0.2 to 0.4 μm. It is a compound that absorbs light. For example, UV lasers include KrF excimer laser (wavelength 0.248 μm), YAG-FHG laser (wavelength 0.266 μm), YAG-THG laser (wavelength 0.355 μm), and the above compounds have their respective wavelengths. Absorbing compounds are preferred.

Further, in the present invention, it is preferable to include a compound that absorbs the wavelength of the laser beam in the portion of the surface of the film to be irradiated with the laser beam before the laser processing step.

As a method for containing, there are coating, spraying and the like, but other methods may be used, and the means for containing is not particularly limited.

By applying the compound to the laser-irradiated portion, for example, the amount of the compound used can be reduced, and the effect of the compound on the physical properties (color change, transparency, etc.) of the film region other than the laser-irradiated portion. Never give. The method of applying the compound to the surface of the film is not particularly limited, as long as a layer containing the compound having a required film thickness can be formed, and an inkjet method, a roller coating method, or the like can be used.

By the way, the laser light means "light amplification by stimulated emission of radiation", and is _{classified into the above-mentioned CO 2} laser light and UV laser light according to the oscillation wavelength.

Further, in the present invention, it is also preferable to wind the tape 982 having embossed or slit stitched on both ends of the film and wind it up.

FIG. 27 (A) is a front view of a film roll 942 wound by winding a tape 982 having embossed or slit meshed on both ends of the film. Further, FIG. 27 (B) is an enlarged view showing a cross section of the circled portion A of FIG. 27 (A).

Normally, when the film is wound around the take-up shaft 934, the tape 982 having embossed or slitted stitches is wound around both ends of the base material Bo and not taken up. Therefore, there is a problem that the film is damaged such as scratches due to dust adhering to the film and winding misalignment.

As in the present invention, by winding the tape 982 with embossed or slit stitched on both ends of the film Bo and winding it, it is possible to prevent damage such as scratches on the film due to dust and winding misalignment. can do.

FIG. 28 is an enlarged view of the tape 982, and FIG. 28 (A) shows the tape 982 sandwiched between the surface of the embossed tape and the film Bo and the film Bo. The cross section is shown, and FIG. 28 (B) shows the surface of the tape subjected to the slit stitch processing and the cross section when the tape 982 is sandwiched between the films Bo and the film Bo. It is a thing.

By winding and winding the embossed or slitted tape 982 as shown in FIG. 28 around both ends of the film Bo, air can pass through the embossed or slitted tape 982, and the film roll 942 Air can flow in and out of the central portion of the film Bo that has been wound up. Therefore, since air can flow in and out of the central portion of the film Bo wound as a roll, it is possible to prevent knicks (bending, imprints) and wrinkles from occurring.

Here, the thickness X of the tape 982 is preferably 50 μm or more, and the embossing or slitting depth x is preferably in the range of 20 to 50% of the thickness of the tape.

If the thickness X of the tape is less than 50 μm, the embossing or slit stitching of the tape 982 will be crushed by the winding pressure. If the embossing or slitting depth x is less than 20% of the tape thickness X, the embossing or slitting of the tape is crushed by the winding pressure, and the film wound as the film roll 942. Air cannot enter or leave the center of Bo. Further, if the embossed or slitted depth x is larger than 50% of the tape thickness X, the strength of the embossed or slitted portion is weak and the shape processed by the winding pressure is crushed.

By winding and winding the embossed or slitted tape 982 in this way, it is possible to prevent the film surface and the film from being damaged by dust and the like, and to prevent knicks and wrinkles from occurring. can do.

The film slit device used in the present invention is preferably composed of a disk-shaped rotary upper blade and a roll-shaped rotary lower blade.

Here, the disk-shaped rotary upper blade of the slit device has a diameter of 30 to 300 mm and a thickness of the cut portion of 0.3 to 3 mm, and the material of the rotary upper blade is super steel, super steel fine particles, SKD. It is preferably either (alloy tool steel) or SKH (high speed tool steel). Further, it is preferable that the toe-in angle of the upper blade is 30 to 90 degrees.

The roll-shaped rotary lower blade has a roll diameter of 75 to 200 mm, and the roll material of the rotary lower blade is preferably any one of super steel, super steel fine particles, SKD, and SKH.

The film slit device used in the present invention may be composed of only a disk-shaped rotary upper blade. In this case, the disk-shaped rotary upper blade of the slit device has a diameter of 30 to 300 mm and a thickness of the cut portion of 0.3 to 3 mm, and the material of the rotary upper blade is super steel, super steel fine particles, SKD. , Or SKH is preferable.

In the present invention, it is preferable that the temperature around the slitter is 20 to 50 ° C. and the humidity is 50 to 70% RH.

Further, in the present invention, it is preferable to provide a suction device in which the periphery of the upper blade is boxed and suction is performed in a wind speed range of 0.8 to 10 m / sec. In this case, the suction position of the end film is on the downstream side in the base transport direction from the slitting point.

In the present invention, it is preferable to provide a mechanism for transporting the slit end film (film fragment) to the next cutting step, for example, providing a mechanism for niping and / or sucking the slit end film. However, it is preferable.

Further, it is preferable to provide a mechanism for niping and / or winding the slit end film.

Here, it is preferable that the draw ratio, that is, the speed of the nip and / or the film to be wound divided by the speed of the slit end film is 0.8 to 1.5.

Further, it is preferable to set the suction pressure to −1000 to −100 Pa. The nip pressure is preferably 0.1 to 17 MPa.

(7) Embossing (Narling) Step The acrylic resin film according to the present invention preferably has embossed regions at both ends in the width direction of the film. The embossing has one or more convex rows substantially parallel to each other in the transport direction in each embossing region. The convex row is a convex region formed intermittently or continuously in the transport direction. In the present specification, a convex row in which a convex region is intermittently formed in the transport direction is referred to as an intermittent convex row, and a convex row in which a convex region is continuously formed in the transport direction is referred to as a continuous convex row. It shall be. When the convex sequence is an intermittent convex column, each convex region that intermittently constitutes the convex column is referred to as a convex region unit.

It is preferable that the embossed regions at both ends in the width direction of the acrylic resin film according to the present invention independently satisfy the requirements of (I) or (II) shown below. That is, the embossed regions at both ends may commonly satisfy the requirement (I), the requirement (II) may be satisfied, or the embossed region at one end satisfies the requirement (I), and the other. The embossed region at the edge may meet the requirement (II). If the embossed regions at both ends commonly meet the requirement (I) or the requirement (II), the embossed regions at both ends may have symmetry with respect to the center line in the width direction. Alternatively, they may be different from each other within a predetermined range. The embossed regions at both ends preferably meet the requirements of (I) or (II) in common and have symmetry with respect to the center line in the width direction. Hereinafter, the requirements of (I) and (II) will be described in detail, but the description of these requirements is intended for one end of the embossed area. In the present specification, the pattern shape of the convex region of the embossed region when viewed from a direction perpendicular to the film surface may be referred to as an embossed pattern.

(I) When the embossed region has only two or more intermittent convex rows, the arrangement of the convex region units of each intermittent convex row is arranged adjacent to any two in the transport direction so as to prevent the entrainment air from coming out. Control is performed between one convex region unit and between any two rows of convex rows adjacent to each other in the width direction.

In the requirement (I), the embossed region has intermittent convex rows, preferably 2 to 7 rows, more preferably 3 to 5 rows. Specifically, for example, in FIG. 29 (A), the film has three rows of intermittent convex rows A1 parallel to the transport direction (MD direction) in the embossed region A10 at one end in the width direction. When the convex sequence is such an intermittent convex column, the individual convex regions constituting the intermittent convex array are referred to as a convex region unit, and are shown by A2 in FIG. 29 (A). All convex region units A2 in all intermittent convex rows A1 usually have the same dimensions and are repeatedly formed in the transport direction at regular intervals.

In the requirement (I), first, the arrangement of the convex region units is controlled between arbitrary two convex region units adjacent to each other in the transport direction. Specifically, the transport direction distance x (mm) (see FIG. 29 (A)) between any two convex region units A2 adjacent to each other in the transport direction in each intermittent convex row A1 is the transport direction length of the convex region unit A2. It should be 0.4 or less, particularly 0.01 to 0.4, preferably 0.01 to 0.25 with respect to y (mm). If the ratio is too large, the entrained air of the film roll is not effectively held over time, so that the film sticking, loosening, wrinkles and breakage cannot be sufficiently suppressed, and the winding misalignment cannot be sufficiently suppressed.

The transport direction distance x (mm) between the convex region units A2 is not particularly limited as long as the above ratio is achieved, and is usually in the range of 0.5 to 3 mm, preferably in the range of 1 to 2 mm.

The length y (mm) in the transport direction of the convex region unit A2 is not particularly limited as long as the object of the present invention is achieved, and is usually in the range of 3 to 20 mm, preferably in the range of 5 to 10 mm.

The requirement (I) further controls the arrangement of the convex region units between any two adjacent convex rows in the width direction. Specifically, for any two rows of convex rows adjacent in the width direction, any one convex region unit in one convex row is on the vertical cross-sectional perspective view with respect to the width direction, and in the transport direction in the other convex row. Arrange so as to overlap two adjacent convex region units.

Specifically, as shown in FIG. 29 (B), any one convex region unit A2a is two convex region units adjacent to each other in the transport direction in adjacent convex rows on the upstream side and the downstream side in the transport direction. It is arranged so as to overlap with A2b and A2c. 29 (B) shows the convex region unit A2c and the second convex region unit A2c closest to the convex region unit A2a in the adjacent intermittent convex rows A1 when one convex region unit A2a is focused on in the film of FIG. 29 (A). It is a vertical cross-sectional perspective view with respect to the width direction which shows the relationship with the convex area unit A2b which is close to. In such a vertical cross-sectional perspective view, if any one convex region unit overlaps only one convex region unit in an adjacent intermittent convex row, the entrainment air of the film roll is not effectively retained over time. , Sticking between films, loose winding, wrinkles and breakage cannot be sufficiently suppressed, and winding misalignment cannot be sufficiently suppressed.

In the vertical cross-sectional perspective view in the width direction, the overlap portion of the convex region unit A2a with the convex region unit A2b on the upstream side in the transport direction overlaps with the transport direction length Z1 (mm) and the convex region unit A2c on the downstream side in the transport direction. The smaller length of the transport direction length Z2 (mm) of the portion is 0.3 or more, particularly 0.3 to 0.5, with respect to the transport direction length y (mm) of the convex region unit. If the ratio is too small, the entrained air of the film roll is not effectively held over time, so that the film sticking, loosening, wrinkles and breakage cannot be sufficiently suppressed, and the winding misalignment cannot be sufficiently suppressed.

The above relationship in which the convex region unit A2a overlaps the convex region units A2b and A2c on the upstream side and the downstream side in the transport direction, respectively, is the same in the present invention as any one convex region unit in any convex row and the adjacent convex row. It is satisfied between the convex region unit and the nearest convex region unit and the second closest convex region unit.

The convex region unit A2 constituting the intermittent convex row A1 is raised at a predetermined height from the region where the convex region is not formed. For example, in FIG. 29B, the convex region unit A2 (A2a, A2b, A2c) is raised from the surface A3 of the region where the convex region is not formed at a predetermined height h. The height h is not particularly limited as long as the object of the present invention is achieved, and is usually 1.5 to 30 μm on average, preferably in the range of 2 to 20 μm.

In the embossed region A10, the area ratio of the convex region is in the range of 20 to 80%. If the area ratio of the convex region is too small, the entrained air of the film roll is not effectively held, so that the effect of suppressing loosening and sticking cannot be obtained. If the area ratio of the convex region is too large, the amount of air entrained in the film roll becomes too large, and the looseness of the film roll deteriorates.

The area ratio of the convex region is the ratio of the total area of the convex region unit A2 to the total area of the embossed region A10. The embossed region A10 is the smallest region separated by a straight line parallel to the transport direction so as to include all the convex regions at one end in the width direction of the film, and is, for example, the region shown by diagonal lines in FIG. 29 (C). be.

The distance a between the embossed region A10 and the end face of the film (see FIG. 29 (C)), the length b in the width direction of the embossed region A10 (see FIG. 29 (C)), and between adjacent convex rows in the width direction. The distance c (see FIG. 29C) is not particularly limited as long as the object of the present invention is achieved.

The distance a is usually 10 mm or less, preferably 5 mm or less.

The length b is usually in the range of 5 to 30 mm, preferably in the range of 10 to 20 mm.

The distance c between the convex columns is not particularly limited as long as the area ratio of the convex region is achieved, and is usually in the range of 0.1 to 5 mm, preferably in the range of 0.5 to 2 mm.

In the acrylic resin film according to the present invention, the film thickness in the central non-embossed region A5 with respect to the length in the width direction, the length in the transport direction, and the width direction is not particularly limited.

The length in the width direction is usually in the range of 500 to 4000 mm, preferably in the range of 1000 to 3000 mm, and more preferably in the range of 1300 to 3000 mm. Conventionally, the longer the length is, the more difficult it is for the entrained air to escape, but since the air is released over time, problems such as loose winding, wrinkles, and breakage are likely to occur. This is because these problems can be effectively suppressed even if the length is long.

The length in the transport direction is usually in the range of 500 to 10000 m, preferably in the range of 2000 to 9000 m, and more preferably in the range of 3000 to 8000 m. Conventionally, the longer the length is, the larger the amount of air entrained is, but the air is released with the passage of time, so that problems such as loose winding, wrinkles, and breakage are likely to occur. This is because these problems can be effectively suppressed even if the length is long.

The film thickness in the non-embossed region A5 is usually in the range of 10 to 200 μm, preferably in the range of 20 to 80 μm. The thinner the thickness, the more easily the acrylic resin film is deformed, so that problems such as loose winding, wrinkles, and breaks are likely to occur. However, in the present invention, these problems are effective even with such a thickness. This is because it can be suppressed.

In the embossed pattern shown in FIG. 30A, the convex region unit A2 has a rectangular shape, but is not particularly limited as long as the object of the present invention is achieved, and is, for example, a rhombus shape and a W shape (M shape). ) It may have a shape, a hexagonal shape, a cross shape, or the like.

Specific examples of the embossing pattern when the convex region unit A2 has a rhombic shape are shown in FIGS. 30 (A) to 30 (C).

30 (A) to 30 (C) are the same as those in FIGS. 29 (A) to 29 (C) except that the convex region unit A2 has a rhombic shape, and thus the description thereof will be omitted. 29 (A) to 29 (C) have the same reference numerals as those in FIGS. 29 (A) to 29 (C) in FIGS. 30 (A) to 30 (C), except that the shape of the convex region unit A2 is different. It shall indicate the same meaning as.

The area shown by the diagonal lines in FIG. 30C is the embossed area A10.

(II) When the embossed region has one or more continuous convex rows, the embossed region may or may not have an intermittent convex row. That is, all the convex rows of the embossed region may consist of only one or more rows, preferably only 2 to 7 rows of continuous convex rows, or one or more rows, preferably 1 to 7 rows of continuous convex rows. It may consist of rows and intermittent convex rows of one or more rows, preferably 1 to 7 rows. As a specific example of the former case, for example, the embossing patterns shown in FIGS. 31 (A) to 31 (C) can be exemplified. As an embodiment of the latter case, for example, the embossing patterns shown in FIGS. 31 (A) to 31 (C) can be exemplified.

31 (A) to 31 (C) are the same as FIGS. 29 (A) to 29 (C) except that all the convex columns are continuous convex columns, and therefore their description is omitted. do. The same reference numerals as those in FIGS. 29 (A) to 29 (C) in FIGS. 31 (A) to 31 (C) are the same as those in FIGS. 29 (A) to 29 (C) except that the convex columns are continuous. It shall indicate the same meaning and content.

32 (A) to 32 (C) are the same as FIGS. 30 (A) to 30 (C), except that the embossed region has one continuous convex row and one intermittent convex row, respectively. Since they are the same, their description will be omitted. The same reference numerals as those in FIGS. 30 (A) to 30 (C) in FIGS. 32 (A) to 32 (C) except that the number of convex rows is different and one convex row is a continuous convex row. , FIGS. 30 (A) to 30 (C) shall have the same meaning and content.

In particular, in the requirement (II), as in the requirement (I), the area ratio of the convex region in the embossed region A10 is in the range of 20 to 80%, preferably in the range of 30 to 60%. If the area ratio of the convex region is too small, the entrained air of the film roll is not effectively held, so that the effect of suppressing loosening and sticking cannot be obtained. If the area ratio of the convex region is too large, the amount of air entrained in the film roll becomes too large, and the looseness of the film roll deteriorates.

The area ratio of the convex region is the ratio of the total area of the convex region unit A2 to the total area of the embossed region A10. The embossed region A10 is the smallest region separated by a straight line parallel to the transport direction so as to include all the convex regions at one end in the width direction of the film, and is, for example, diagonal lines in FIGS. 30 (C) and 32 (C). This is the area indicated by.

In the requirement (II), the intermittent convex arrangement that the embossed region may have is not particularly limited, and may be, for example, the same intermittent convex arrangement as in the requirement (I), or the intermittent convex arrangement. It may be an intermittent convex row other than.

The acrylic resin film according to the present invention has an embossed pattern other than the intermittent convex rows and / or continuous convex rows formed substantially parallel to the transport direction in the above-mentioned requirements (I) and (II). It does not prevent the embossed region from having a formed convex region or a randomly (irregularly) formed convex region.

In the present invention, in the nerling process for forming the embossed portion, the processing temperature of the narling process is T (° C.), the glass transition temperature of the base film is Tg (° C.), and the time during which the base film is in contact with the embossed ring is s (seconds). ), It is preferable to perform the nerling process under the condition that the following relational expression is satisfied to produce a roll-shaped film.

0.75 ≦ (T-Tg) × s ≦ 1.00
The time s (seconds) in which the base film is in contact with the embossing ring can be changed by changing the film transport speed, the nip width, in other words, the pressing pressure. The nip width and pressing pressure can be changed by adjusting the hardness of the rubber on the surface of the back roll made of the rubber roll, or by changing the diameters of the embossed ring and the embossed back roll.

In the above, if the value of (T-Tg) × s is less than 0.75, the embossing height cannot be sufficiently obtained and the effective knurling in the wound state becomes low, so that the films stick to each other. Is not preferable because the film is not flattened due to the occurrence of the film or the occurrence of convex local deformation.

Further, when the value of (T-Tg) × s exceeds 1.00, the embossing height becomes too high, and as a result, the effective knurl in the wound state becomes high, so that the center of the winding is on the back of the horse. It is not preferable because it is dented in such a shape and the flatness as a film cannot be maintained. Further, when the temperature at the time of knurling, which is the value of T, is increased, the value of (T-Tg) × s also increases, but in this case, the temperature of T is up to the extent that the value of (T-Tg) × s exceeds 1.00. If the temperature is high, a whiskers-like failure will occur, which is not preferable.

Further, in the present invention, it is preferable to apply cold air at 10 to 20 ° C. to the film discharge side of the embossing engraving roller during the knurling process. Here, when the embossing process is performed, the film discharge side of the embossing engraving roller is blown with cold air at 10 to 20 ° C., because the film and the ring portion are cooled immediately after the embossing process, so that the resin portion melted by heat is cooled and solidified. Therefore, the generation of thread-like foreign matter (beard-like foreign matter) can be suppressed, and a sufficiently high embossing height can be obtained.

The acrylic resin film according to the present invention preferably has an effective nal defined by the following formula of the roll-shaped film of 0.5 to 7.0 μm.

Effective knurl = (embossed roll cross-sectional area-core cross-sectional area) / winding length-average film thickness In the above, if the effective knurl is 0.5 μm or more, the film does not stick to each other and is convex. It suppresses the occurrence of local deformation and improves the flatness of the film. Further, when the effective knurl is 7.0 μm or less, the center of the winding is not dented into a shape like the back of a horse, and the flatness as a film is improved.

In the acrylic resin film according to the present invention, the number of whisker-like foreign substances adhering to the periphery of the embossed portion of the roll-shaped film ^{is preferably 0 to 50 / cm 2} , preferably 0 to 20 / cm ² . It is more preferable to have 0 to 10 pieces / cm ² .

In the above, the number of whisker-like foreign matter adhering to the embossed portions around the film is preferably as small as possible, and if the number of whisker foreign matter more than 50 / cm ^2, is removed in the cleaning device at the time of processing as a polarizing plate It is not preferable because it cannot be completely squeezed, and if it enters between the polarizing element and the film as a foreign substance and is incorporated into a liquid crystal display device, it causes an image defect. The same applies when the surface is coated with antireflection treatment or antiglare treatment.

Here, the height h (μm) of the embossed portion is set in the range of 0.05 to 0.3 times the film thickness H, and the width W is set in the range of 0.005 to 0.02 times the film width L. do. The embossed portions may be formed on both sides of the film. In this case, the height h1 + h2 (μm) of the embossed portion is set in the range of 0.05 to 0.3 times the film thickness H, and the width W is set in the range of 0.005 to 0.02 times the film width L. .. For example, when the film thickness is 40 μm, the height h1 + h2 (μm) of the embossed portion is preferably set in the range of 2 to 12 μm, and the embossed portion width is preferably set in the range of 5 to 30 mm.

The lower limit of the height of the embossed part is the height required to prevent partial adhesion unevenness between the films, while the upper limit is too high for the embossed part, so the form of the roll-shaped rolled product is the back of the horse. This is because it deforms into a polygonal shape and induces a failure.

Regarding the width of the embossed portion, we would like to reduce it because the embossed portion will eventually become a loss portion. The required embossed width.

However, it is also linked to the height of the embossed portion described above, and it is necessary to set the height of the embossed portion × the width of the embossed portion that clears all of the convex shape, the pyramid shape, the back of the horse, the polygonal shape, and the unwinding failure.

The film after embossing is preferably wound by the following winding method.

The winding method consists of a straight winding step of winding the film around the winding core so that the side edges of the film are aligned, and after the straight winding step, the side edges are periodic in a certain range with respect to the width direction of the film. It is preferable to have an oscillating winding step of winding the film around the winding core by periodically vibrating the film or the winding core in the width direction of the film so as to shift to.

In particular, when the winding length of the film reaches a predetermined winding length at the time of switching within a range of 10 to 30% of the total winding length of the film, the straight winding process is switched to the oscillating winding process. Is preferable.

The film winding device includes a film winding unit that rotates the winding core to wind the film around the winding core, and an oscillate in which the film is periodically displaced on the winding core in the width direction of the film within a certain range. The oscillating portion that vibrates the film or the core in the width direction of the film in conjunction with the winding of the film so as to be wound, and the winding length of the film reaches a predetermined winding length at the time of switching. Occasionally, it is preferable to include a switching unit for switching the winding of the film from the straight winding to the oscillating winding.

The oscillating winding will be described below.

As shown in FIG. 33, the film production line B10 includes a film production apparatus B11 and a winding apparatus B12. The film manufacturing apparatus B11 manufactures the film B13 by the solution film forming method. In the solution film forming method, first, a dope is prepared using a raw material. Then, the prepared dope is cast on the endless support to form a cast film. When the flow film becomes self-supporting, the flow film is peeled off from the endless support. The film B13 is formed by drying the peeled cast film with hot air or the like. The formed film B13 is sent to the winding device B12 via the knurling roller B15. The knurling roller B15 forms minute irregularities on both side edges (ears) of the film B13 in the width direction by embossing or the like. The height of the unevenness formed by the knurling roller is preferably in the range of 0.5 to 20 μm.

As shown in FIGS. 33 and 34, the winding device B12 includes a winding shaft B19, a winding core holder B20, a winding core B21, a turret B22, guide rollers B23, B24, a dancer roller B25, an encoder B27, and an oscillating unit B29. It includes a take-up motor B30, a controller B31, and a dancer section B32. The size of the film to be wound in the winding device B12 is not particularly limited, but for example, a film having a total winding length in the range of 2000 to 10000 m and a width in the range of 500 to 2500 mm is preferable.

As shown in FIG. 34, the take-up shaft B19 is attached to the turret B22 by a cantilever support mechanism. The cantilever support mechanism is a mechanism that supports only one end of the take-up shaft B19. A winding core B21 is attached to the winding shaft B19. Both ends of the winding core B21 are sandwiched by the winding core holder B20 of the winding shaft B19. The winding core holder B20 is slidably attached to the winding shaft B19 in the axial direction (Y direction) of the winding shaft B19 and is non-rotatably attached to the winding shaft B19. A take-up motor B30 is connected to one end of the take-up shaft B19, and is configured to rotate the take-up shaft B19. By this rotation, the winding core B21 also rotates, and the film B13 can be wound around the winding core B21. By winding the film B13, a film roll B38 in which the film B13 is wound in a roll shape is obtained.

A shift mechanism B28 is attached to the turret B22 at the attachment end of the take-up shaft B19. The shift mechanism B28 reciprocates the winding core holder B20 on the take-up shaft B19 in the axial direction. The shift mechanism B28, the take-up shaft B19, and the winding core holder B20 constitute an oscillating portion B29. By operating the oscillating portion B29 and reciprocating the winding core holder B20 on the winding shaft B19 in the Y direction by the shift mechanism B28, the position of the side edge B13a is in the range of the amplitude Wo each time the film B13 is laminated. Allows oscillated winding in which the film B13 is wound while shifting within. When the oscillating portion B29 is not operated, straight winding is possible in which both side edges of the film B13 are aligned. This switching between straight winding and oscillating winding is performed by the controller B31.

Here, in the oscillating winding, the oscillating width Wo, which is the swing width thereof, can be arbitrarily set, and the amplitude Wo is preferably in the range of 10 to 30 mm, and if it is within the above range, the amplitude Wo is constant. In addition to fixing the value, it may be gradually increased, decreased, or decreased after the increase.

The guide rollers B23 and B24 and the dancer roller B25 guide the film B13 from the film manufacturing apparatus B11 in the transport direction (X direction). Further, the dancer roller B25 adjusts the winding tension of the film B13 by moving the film B13 in the vertical direction (Z direction) by the shift mechanism B26. The dancer portion B32 is configured by the shift mechanism B26 and the dancer roller B25. The encoder B27 transmits an encoder pulse signal to the controller B31 each time the guide roller B24 rotates at a constant rotation angle. The guide roller B24 may be provided with a tension sensor for measuring the winding tension of the film B13.

The controller B31 controls the drive of the oscillating unit B29, the take-up motor B30, and the dancer unit B32. The controller B31 includes a take-up information input unit B39, a LUT memory B40, a winding length specifying unit B41 at the time of switching, a winding length measuring unit B42, and a switching determination unit B43. Winding information such as the total winding length, thickness, width, outer diameter of the winding core B21, and winding tension of the film B13 is input to the winding information input unit B39.

The LUT memory B40 stores the winding length (winding length at the time of switching) of the film B13 when switching from straight winding to oscillating winding for each winding information. The winding length at the time of switching is preferably preset in the range of 10 to 30% with respect to the total winding length of the film B13, and more preferably preset in the range of 15 to 25% with respect to the total length of the film B13. There is.

The winding length at the time of switching is set in the above range for the following reasons. As shown in FIG. 35, the graph B50 shows the relationship between the stress generated in the film B13 in the circumferential direction of the winding core B21 and the winding length. The stress in the circumferential direction of the film B13 is obtained based on the rotational torque of the winding core B21 and the tension due to the dancer portion B32. When the rotational torque of the winding core B21 becomes larger than the tension by the dancer portion B32, the stress in the circumferential direction of the film B13 becomes positive, and when the rotational torque of the winding core B21 becomes smaller than the tension by the dancer portion B32. It becomes negative. As shown in FIG. 36, in the film roll B38 in which the film B13 is wound around the core B21, the circumference of the film B13 at the point P1 when a force is applied from the point P1 toward the outside in the circumferential direction. The stress in the direction is said to be positive. Further, when a force is applied in the circumferential direction toward the point P2, the stress in the circumferential direction at the point P2 of the film B13 is said to be negative.

The graph B50 of FIG. 35 is obtained in advance from a well-known stress calculation formula based on the tension at the start of winding and the tension at the end of winding of the film B13. The stress distribution pattern in the circumferential direction of the film B13 has various values and negative values depending on parameters such as the thickness, width, winding length, and outer diameter of the winding core of each film and the change state of the winding tension pattern. However, it is known from the film winding results so far that the distribution pattern is substantially the same as that in FIG. 35.

As shown in the graph B50, the stress in the circumferential direction of the film B13 is positive (+) in the portion of the film roll B38 where the winding length on the winding core B21 side is small. In FIG. 35, the reference numeral L1 is attached to the winding length in which the stress decreases from the place where the winding length is 0 and the winding length changes to negative (−). In this way, at the beginning of winding, the stress in the circumferential direction decreases sharply as the winding length increases. Then, the stress in the circumferential direction further decreases and enters the negative (−) region. In FIG. 35, the reference numeral LE is attached to the winding length corresponding to the completion of winding. Then, in the negative (−) region, the stress in the circumferential direction indicates the minimum value Smin. In FIG. 35, the reference numeral Lmin is attached to the winding length in which the stress in the circumferential direction indicates the minimum value Smin. In the portion where the winding length exceeds Lmin, the stress in the circumferential direction gradually increases as the winding length becomes longer, and enters the positive (+) region. The reference numeral L2 is attached to the winding length in which the stress in the circumferential direction increases after showing the minimum value Smin and changes positively. Here, when the stress in the circumferential direction of the film B13 is in the negative region, the rotational torque of the winding core B21 becomes larger than the tension due to the dancer portion B32, and the film B13 is unwound. The surface pressure (surface pressure) drops. Graph B51 of FIG. 37 shows the change in the surface pressure at both end portions of the film B13 when winding is performed by straight winding, and graph B52 of FIG. 38 shows the change when winding is performed by oscillating winding. The change in the surface pressure at the left end of the film B13 is shown, and the graph B53 shows the change in the surface pressure at the right end. As shown in these graphs B51 to B53, at the beginning of winding the film B13, the decrease in the surface pressure when the film B13 is wound is relatively smaller than the decrease in the surface pressure when the film is wound by the oscillating winding. The left end portion of the film B13 is the left end portion in the X direction, and the right end portion is the right end portion in the X direction.

A decrease in the surface pressure at the beginning of winding the film B13 causes the film roll B38 after winding to loosen or shift. Therefore, as described above, straight winding is performed while the surface pressure decreases at the beginning of winding of the film B13, that is, while the stress in the circumferential direction of the film B13 is in the negative region, and then the winding length is the total winding length. When the range is in the range of 10 to 30%, the winding is switched to the oscillated winding. As a result, at the beginning of winding the film B13, a decrease in surface pressure is suppressed by winding straight, and when the stress in the circumferential direction of the film B13 escapes from the negative region, the film B13 is wound by oscillating winding. Therefore, the surface pressure can be dispersed in the left-right direction with respect to the width direction of the film B13, and the occurrence of ear elongation can be reduced. The winding length at the time of switching, which is determined in advance as the timing for switching from straight winding to oscillating winding, may be determined based on the relationship between the stress in the circumferential direction and the winding length as shown in Graph B50, as in the present embodiment. When the winding length of the film B13 reaches the switching winding length obtained in this way, the controller B31 switches from straight winding to oscillating winding. The timing for switching from straight winding to oscillating winding is more preferably when the winding length is in the range of 15 to 25% of the total winding length.

When switching from straight winding to oscillating winding when the winding length is 10% or more of the total winding length, the surface pressure drops sharply at the beginning of winding of the film B13 as compared with the case of switching when the winding length is less than 10%. Prevents you from doing so more reliably. Therefore, it is possible to more reliably prevent the film roll B38 from being loosened or misaligned. Further, when the winding length exceeds 30% of the total winding length and then switched, the film B13 is wound in a straight winding even after the stress in the circumferential direction has escaped from the negative region, so that it is 30% or less. Compared with the case of switching at the time of, the film roll B38 is more likely to have ear elongation. Therefore, by switching from straight winding to oscillating winding when the winding length is 30% or less of the total winding length, it is possible to more reliably prevent the occurrence of ear elongation than when switching after exceeding 30%. ..

The winding length specifying unit B41 at the time of switching collates the winding information stored in the LUT memory B40 with the winding information input to the winding information input unit B39, and switches corresponding to the input winding information. Specify the time volume length. The winding length measuring unit B42 measures the winding length of the film B13 wound around the winding core B21 based on the encoder pulse signal from the encoder B27.

The switching determination unit B43 determines whether or not the winding length measured by the winding length measuring unit B42 exceeds the winding length specified by the switching winding length specifying unit B41. If it is determined that the winding length exceeds the winding length at the time of switching, an oscillating winding start signal is transmitted to the oscillating unit B29. When the oscillating unit B29 receives the oscillated winding start signal, the oscillating unit B29 winds the film B13 so that the side edges B13a of the film are aligned with the straight winding, and shifts the position of the side edges B13a within the range of the amplitude Wo to move the film B13. The winding of the film B13 is changed to the oscillating winding to be wound.

Next, the operation of the winding device will be described with reference to the flowchart shown in FIG. 39. First, the winding information of the film B13 to be wound is input to the winding information input unit B39. The winding length specifying unit B41 at the time of switching collates the winding information input to the winding information input unit B39 with the winding information stored in the LUT memory B40, thereby switching corresponding to the input winding information. Specify the time volume length.

Then, the winding of the film B13 is started by straight winding. At the time of winding, every time the guide roller B24 rotates at a constant rotation angle, an encoder pulse signal is transmitted from the encoder B27 to the controller B31 at regular time intervals. Based on this encoder pulse signal, the winding length of the film B13 is measured by the winding length measuring unit B42.

Whether or not the winding length measured by the winding length measuring unit B42 exceeds the winding length at the time of switching is sequentially determined by the switching determination unit B43. When it is determined that the winding length exceeds the winding length at the time of switching, the oscillating winding start signal is transmitted from the controller B31 to the oscillating unit B29. Upon receiving the oscillating winding start signal, the oscillating unit B29 vibrates the winding core B21 along the axial direction (Y direction) with a constant amplitude Wo. As a result, the winding of the film B13 is changed from straight winding to oscillating winding.

When the winding of the film B13 is completed, the film roll B38 is removed from the winding shaft B19. The film roll B38 is transported to various factories by transportation means such as trucks. At that time, since the inside of the winding core of the film roll B38 is a straight winding, there is no looseness in the winding, and the film roll B38 does not shift even if there is vibration during transportation. In addition, since the outside of the core of the film roll B38 is oscillated, the occurrence of ear elongation is suppressed.

In the above embodiment, the film B13 is wound by vibrating the winding core B21 in the width direction of the film B13. However, the method of oscillating winding is not limited to this method, and a well-known method may be used. For example, the film B13 itself may be vibrated in the width direction without moving the winding core B21.

(8) Return material recovery (trimming process)
The return material recovery is a step of recovering a portion where the end portion in the width direction of the film is cut while transporting the film in the slit step (6). For example, the end portion where the trace remains because it was gripped by the tenter in the stretching step is removed. Cutting and recovery of the ends are usually performed at both ends in the film width direction. An appropriate amount of the recovered return material is brought into the dissolution step, dissolved in a solvent, and used for dope preparation.

The trimming step includes an end cutting step for cutting the end portion in the width direction of the film and an end collecting step for collecting the cut end portion.

In the end cutting step, while the film is being conveyed in the conveying direction T, the end of the film is cut by a cutting means such as a fixed cutter, and the film body is provided to the next step such as the winding step.

The width (width) x of the end to be cut is not particularly limited, and such x is specifically preferably in the range of, for example, 30 to 300 mm, particularly preferably in the range of 50 to 130 mm. ..

In the end collection stage, the cut film end is collected from the suction port. The suction port usually has a cylindrical shape, particularly a cylindrical shape, and suction is performed in the suction direction by a suction device. The suction speed is not particularly limited as long as the object of the present invention is achieved.

At this stage, when the cut film end is collected from the suction port, transport air is supplied from the upstream side and the downstream side in the film transport direction toward the suction port opening to transport the film end portion b.・ Assist in collection. The transport air supply speed V1 from the upstream side and the transport air supply speed V2 from the downstream side are independently in the range of 100 to 6000%, preferably 500 to 5500% with respect to the film transport speed. Yes, their ratio V1 / V2 is less than 1, especially in the range 0.1-0.9, preferably in the range 0.3-0.9. As a result, it is possible to suppress fluttering and meandering of the cut end portion, and to sufficiently smoothly cut and collect the cut end portion.

The temperature T1 of the transport air from the upstream side and the temperature T2 of the transport air from the downstream side are not particularly limited, and are usually independently higher than the atmospheric temperature by a range of 0 to 50 ° C. By independently setting the temperatures T1 and T2 higher than the atmospheric temperature in the range of 0 to 50 ° C., particularly in the range of 0 to 45 ° C., the shrinkage difference between the support surface side and the anti-support surface side at the film end 80b. Can be reduced. As a result, since the meandering of the end portion can be suppressed more effectively, the clogging of the end portion in the suction port and the pipe connected to the suction port can be further sufficiently suppressed. The ambient temperature is the temperature of the ambient atmosphere in which this step is performed, and the temperature at the center of the support surface of the film in the end cutting step in the width direction is used, and can be measured by a non-contact thermometer.

The temperature T1 of the transport air is usually in the range of 30 to 170 ° C., particularly preferably in the range of 30 to 150 ° C.

The temperature T2 of the transport air is usually in the range of 30 to 170 ° C., particularly preferably in the range of 30 to 150 ° C.

The atmospheric temperature is usually in the range of 30 to 120 ° C, particularly preferably in the range of 30 to 100 ° C.

The transport air from the upstream side is supplied from the upstream side supply device, and the transport air from the downstream side is supplied from the downstream side supply device. When the transport air is heated, as a specific example of the heating means, for example, a hot air heater, a temperature control roll, an IR (infrared) heater, or the like is used.

The distance L1 between the supply port of the upstream supply device and the opening of the suction port and the distance L2 between the supply port of the downstream supply device and the opening of the suction port are more sufficient for fluttering and meandering at the cut end. From the viewpoint of suppressing the above, it is preferable that the range is 20 to 200 mm, particularly preferably 30 to 180 mm.

The angle θ1 between the supply direction of the transport air from the upstream side and the suction direction (the transport direction of the film end in the suction port) and the angle between the supply direction and the suction direction of the transport air from the downstream side are the same as those of the present invention. It is not particularly limited as long as the purpose is achieved, and is independently in the range of 10 to 90 °, particularly in the range of 30 to 85 °, from the viewpoint of further sufficiently suppressing the fluttering and meandering of the cut end. Is preferable.

As the upstream side supply device and the downstream side supply device, those having a circular supply port are usually used.
It is preferable that the trimmed end film is rapidly crushed, transported as small pieces, and stored in a storage container for returning material collection.
Since a cutter that crushes the return material generally generates heat, the temperature becomes high, and it is easy for acrylic resin having a low Tg to fuse with the cutter blade to prevent crushing. The cutter is preferably provided with a cooling mechanism, and as a cooling method thereof, for example, a cooling medium such as dry ice may be sprayed so as to accompany the film.

The amount of residual solvent in the film subjected to this step, particularly the edge cutting step, is preferably in the range of 0 to 50% by mass, particularly preferably in the range of 0 to 20% by mass. This is because the shrinkage difference between the support surface side and the anti-support surface side at the film end can be more effectively reduced while the film edge can be easily cut.

(9) Solvent Recycling Step In the method for producing an acrylic resin film of the present invention, it is preferable to recycle the organic solvent used. It is preferable to introduce a dry gas containing an organic solvent vapor generated in the drying step into the recycling step to remove impurities and regenerate the organic solvent. Such a recycling process will be described with reference to the following figures.
FIG. 40 is a schematic view showing an example of a film forming line used in the present invention.
As shown in FIG. 40, the film forming line 309 is divided into a charging zone 310, a band zone 311 and a drying zone 312. The charging zone 310 includes a charging tank 314, a pump 315, and a filter 316. Further, in the charging tank 314, the dope 313 is uniformly prepared by the stirring blade 317. The prepared dope 313 is sent to the casting die 320 of the band zone 311 via the pump 315 and the filter 316.
The band zone 311 is provided with a spreading band 323 spanned by rollers 321 and 322, and the spreading band 323 is rotated by a drive device (not shown). A casting die 320 is provided on the casting band 323. The dope 313 is sent from the charging tank 314 by the pump 315, and after the impurities are removed by the filter 316, it is sent to the casting die 320. Dope 313 is cast from the casting die 320 onto the casting band 323. The dope 313 has self-supporting property by being gradually dried while being conveyed by the casting band 323, and is stripped from the casting band 323 by the stripping roller 324 to form a film 325. Further, the film 325 is stretched to a predetermined width by the tenter 326 and dried while being conveyed. As is well known, the band zone 311 is divided into a plurality of chambers by a partition wall as needed, and gas is discharged and drying gas is sent out to each of these chambers.

The film 325 sent from the tenter 326 to the drying zone 312 is wound around a plurality of rollers 327 and dried while being conveyed in the drying zone 312. The dried film 325 is taken up by a winder 328.
The gas (hereinafter, also referred to as hot air gas) 350 containing the solvent volatilized in the drying zone 312 and which is hot air is treated by using the solvent recovery line 331. After being sent to the heat exchanger 351, it is blown to the open chamber 353 by the blower 352.
Then, by sucking the gas 350 and the atmosphere 354 from the open chamber 353 by the blower 355, it is possible to make the downstream side (blower 355 side) of the open chamber 353 a pressure lower than the atmospheric pressure (negative pressure). The form of the open chamber used in the present invention is not limited to that shown in the figure, and any known open chamber can be used. Further, the device for making a part of the solvent recovery line 331 in a negative pressure state is not limited to the open chamber, and it is also possible to use a blower fan having a function of making a part of the line in a negative pressure state.

Further, a cooler 356 for cooling the gas 350, a pretreated activated carbon 357 for the gas drying process, and a dehumidifier 358 are installed between the open chamber 353 and the blower 355, but these are appropriately used. It may be omitted.

Further, the gas 350 is selectively sent by the blower 355 to any of the adsorbers 359, 360 and 361 by a switching valve (not shown), and the volatilized solvent contained in the gas 350 is adsorbed by the adsorbers 359 and 360. , 361. Further, the gas after the adsorption treatment is adjusted to a predetermined temperature by the temperature controller 362 and then sent to the heat exchanger 351 by the blower 363. Then, after heat exchange with the hot air gas 350 described above and heating, the heat is further heated to a predetermined temperature by the heater 364, and the gas is sent into the drying zone 12 again and reused as the drying air.

The volatile solvent component adsorbed on the adsorbers 359, 360 and 361 is desorbed by the desorbing gas 370 (usually steam) and sent out to the condenser 371. The desorbed gas 370 is condensed and liquefied by the condenser 371, and the liquid is sent to the decanter 372 as a recovery solvent. Further, the non-liquefied gas component is sent out to the blower 355 again, sent to the adsorbents 359, 360, and 361, and is adsorbed and recovered.

The recovered solvent (organic solvent) introduced into the decanter 372 is separated into a crude hydrophilic solvent (including water) and a crude hydrophobic solvent and sent to the crude hydrophilic solvent tank 381 and the crude hydrophobic solvent tank 382. The crude hydrophilic solvent is separated into water and a hydrophilic solvent in the distillation column 383, and the water is drained or recycled. The hydrophilic solvent is stored in a hydrophilic solvent tank 384 for reuse. The crude hydrophobic solvent has a residual monomer component present in the acrylic resin and the rubber particles, and it is preferable to provide a distillation column 385 for separating the residual monomer component. The hydrophobic solvent separated in the distillation column 385 is stored in the hydrophobic solvent tank 386 for reuse. The solvent stored in the hydrophilic solvent tank 384 and the hydrophobic solvent tank 386 is adjusted to an appropriate mixing ratio and sent to the purified solvent tank 376. The purification solvent in the purification solvent tank 376 is sent to the preparation device 378, stirred, and then sent to the preparation tank 314 to be reused as a dope preparation solvent.

Particularly preferably used organic solvents in the present invention are dichloromethane and lower alcohols. Further, among the residual monomers of the acrylic resin, a typical one is methyl methacrylate. Therefore, the heat exchanger needs to control the dry gas to a temperature at which dichloromethane, lower alcohol, and methyl methacrylate do not condense. In the decanter, the upper layer is mainly water and lower alcohol, and the lower layer is mainly dichloromethane and methyl methacrylate. Each distillation column is optimally designed to separate water from lower alcohols and dichloromethane from methyl methacrylate.
In order to ensure these separations, the decanter 372 and the distillation columns 383 and 385 may be provided in multiple stages, or pipes may be provided to appropriately return the components immature to the separation to the upstream process.

≪Materials that make up acrylic resin film≫
Hereinafter, the materials used in the method for producing the acrylic resin film of the present invention will be described in detail.
The method for producing an acrylic resin film of the present invention is characterized by dissolving an acrylic resin with an organic solvent and adding an additive to dope it. The material that can be used in the present invention is not limited to the following, and a known material can be appropriately used as a component thereof.

(1) Acrylic resin (constituent monomer type)
As the acrylic resin, any suitable (meth) acrylic resin is used as long as the glass transition temperature (Tg) is in the range of 120 to 180 ° C. and the weight average molecular weight is 300,000 to 4 million. obtain. For example, poly (meth) acrylic acid esters such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymers, methyl methacrylate- (meth) acrylic acid ester copolymers, methyl methacrylate-acrylic acid esters. -(Meta) acrylic acid copolymer, (meth) methyl acrylate-styrene copolymer (MS resin, etc.), polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer) , Methyl methacrylate- (meth) norbornyl acrylate copolymer, etc.).
More specifically, a resin homopolymerized or copolymerized with a combination arbitrarily selected from the monomers exemplified below, and further, a cyclization reaction, a dehydration condensation reaction, a hydrogen addition reaction, and removal of a protective functional group with the resin. Among the resins that have undergone a post-reaction such as an elimination reaction, those having a (meth) acrylic acid ester in an amount of 50% or more by weight.

Examples of the monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth). ) S-butyl acrylate, t-butyl (meth) acrylate, n-amyl (meth) acrylate, s-amyl (meth) acrylate, t-amyl (meth) acrylate, n- (meth) acrylate Hexil, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclohexylmethyl (meth) acrylate, octyl (meth) acrylate, (meth) Lauryl acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, ( 2-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, ( 4-Hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, tetrahydroflufuryl (meth) acrylate, (meth) acrylic Glycidyl acid, β-methylglycidyl (meth) acrylate, β-ethylglycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate , (Meta) acrylic acid esters such as α-hydroxymethylacrylic acid methyl, α-hydroxymethylacrylic acid ethyl and the like.

Isobutyl methacrylate, 2-methylbutyl methacrylate, 2-ethylbutyl methacrylate, 2-isopropylbutyl methacrylate, 2-isopropyl-4-methylbutyl methacrylate, 2,3-dimethylbutyl methacrylate, 2-methylpentyl methacrylate, methacrylic 2-Ethylpentyl acid, 2-propylpentyl methacrylate, 2-isopropylpentyl methacrylate;

S-butyl methacrylate, 1-methylbutyl methacrylate, 1-methylpentyl methacrylate, 1,3-dimethylbutyl methacrylate, 1,2-dimethylpropyl methacrylate, 1,2-dimethylbutyl methacrylate, 1,methacrylate 1, 2-Dimethylpentyl, 1,2,3-trimethylbutyl methacrylate, 2-ethyl-1-methylbutyl methacrylate, 2-ethyl-1-methylpentyl methacrylate, 2-ethyl-1,3-dimethylbutyl methacrylate, 1-Methyl-2-propylpentyl methacrylate, 2-isopropyl-1-methylpentyl methacrylate, 2-isopropyl-1,3-dimethylbutyl methacrylate, 1-ethylpropyl methacrylate, 1-ethylbutyl methacrylate, methacrylic acid 1-Ethylpentyl, 1-ethyl-3-methylbutyl methacrylate, 1-ethyl-2-methylpropyl methacrylate, 1-ethyl-2-methylbutyl methacrylate, 1-ethyl-2-methylpentyl methacrylate, 1 methacrylate -Ethyl-2,3-dimethylbutyl, 1,2-diethylbutyl methacrylate, 1,2-diethylpentyl methacrylate, 1,2-diethyl-3-methylbutyl methacrylate, 1-ethyl-2-propylpentyl methacrylate , 2-Isopropyl-1-ethylpentyl methacrylate, 1-ethyl-2-isopropyl-3-methylbutyl methacrylate, 1-propylbutyl methacrylate,

1-propylpentyl methacrylate, 3-methyl-1-propylpentyl methacrylate, 1-isopropylbutyl methacrylate, 2-methyl-1-propylbutyl methacrylate, 2-methyl-1-propylpentyl methacrylate, 2 methacrylate , 3-Dimethyl-1-propylbutyl, 2-ethyl-1-propylbutyl methacrylate, 2-ethyl-1-propylpentyl methacrylate, 2-ethyl-3-methyl-1-propylbutyl methacrylate, 1 methacrylate , 2-Dipropylpentyl, 2-isopropyl-1-propylpentyl methacrylate, 2-isopropyl-3-methyl-1-propylbutyl methacrylate, 1-isopropylpentyl methacrylate, 1-isopropyl-3-methylbutyl methacrylate, 1-isopropyl-2-methylpropyl methacrylate, 1-isopropyl-2-methylbutyl methacrylate, 1-isopropyl-2-methylpentyl methacrylate, 1-isopropyl-2,3-dimethylbutyl methacrylate, 2-ethyl methacrylate -1-Isopropylbutyl, 2-ethyl-1-isopropylpentyl methacrylate, 2-diethyl-1-isopropyl-3-methylbutyl methacrylate, 1-isopropyl-2-propylpentyl methacrylate, 1,2-diisopropylpentyl methacrylate , 1,2-Isopropyl-3-methylbutyl methacrylate;

T-butyl methacrylate, 1,1-dimethylpropyl methacrylate, 1-ethyl-1-methylpropyl methacrylate, 1,1-diethylpropyl methacrylate, 1,1-dimethylbutyl methacrylate, 1-ethyl methacrylate- 1-Methylbutyl, 1,1-diethylbutyl methacrylate, 1-methyl-1-propylbutyl methacrylate, 1-ethyl-1-propylbutyl methacrylate, 1,1-dipropylbutyl methacrylate, 1,1 methacrylate , 2-trimethylpropyl, 1-ethyl methacrylate-1,2-dimethylpropyl, 1,1-diethyl-2-methylpropyl methacrylate, 1-isopropyl-1-methylbutyl methacrylate, 1-ethyl-1-ethyl methacrylate-1- Isopropylbutyl, 1-isopropyl-1-propylbutyl methacrylate, 1-isopropyl-1,2-dimethylpropylmethacrylate, 1,1-diisopropylpropyl methacrylate, 1,1-diisopropylbutyl methacrylate, 1,1 methacrylate -Diisopropyl-2-methylpropyl;

4-Methylcyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, 4-isopropylcyclohexyl methacrylate, 2-isopropylcyclohexyl methacrylate, 4-t-butylcyclohexyl methacrylate, 2-t-butylcyclohexyl methacrylate;

2-Norbornyl Methacrylic Acid, 2-Methyl-2-Norbornyl Methacrylic Acid, 2-Ethyl-2-Norbornyl Methacrylic Acid, 2-Isobornyl Methacrylic Acid, 2-Methyl-2-Isobornyl Methacrylic Acid, 2-Ethyl-2-Ethacrylate Isobornyl, 8-tricyclomethacrylic acid [5.2.1.02,6] decanyl, 8-methyl-8-tricyclomethacrylic acid [5.2.1.02,6] decanyl, 8-ethyl-8-ethylmethacrylate Tricyclo [5.2.1.02,6] decanyl, 2-adamantyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 1-adamantyl methacrylate, 2-adamantyl methacrylate Examples thereof include fenquil, 2-methyl-2-phenyl methacrylate, 2-ethyl-2-phenyl methacrylate, decalin-1-yl methacrylate, and decalin-2-yl methacrylate.

(Copolymerizable monomer)
Examples of copolymerizable monomers include (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide; (meth) acrylic acid, crotonic acid, sucrose, vinyl benzoic acid and the like. Unsaturated monocarboxylic acids; unsaturated polyvalent carboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid; monosuccinate (2-acryloyloxyethyl), monosuccinate (2-methacryloyloxyethyl) ) Etc., unsaturated monocarboxylic acids in which the chain is extended between unsaturated groups and carboxy groups; unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; styrene, α-methylstyrene, α-chlorostyrene. , P-t-butylstyrene, p-methylstyrene, p-chlorostyrene, o-chlorostyrene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, vinyltoluene, methoxystyrene and other aromatic vinyls; methyl N-substituted maleimides such as maleimide, ethylmaleimide, isopropylmaleimide, cyclohexylmaleimide, phenylmaleimide, benzylmaleimide, naphthylmaleimide; conjugated dienes such as 1,3-butadiene, isoprene, chloroprene; vinyl acetate, vinyl propionate, vinyl butyrate , Vinyl esters such as vinyl benzoate; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether. , Vinyl ethers such as methoxypolyethylene glycol vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether; N such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, N-vinylacetamide and the like. -Vinyl compounds; unsaturated isocyanates such as isocyanatoethyl (meth) acrylate, allyl isocyanate; vinyl cyanide such as acrylonitrile and methacrylonitrile; and the like.

(Other acrylic resins)
The acrylic resin represented by the following general formula (E) and having an average molecular weight (Mw) in the range of 1000 to 30,000 is highly compatible with the acrylic resin according to the present invention, and is used in combination from the viewpoint of improving heat resistance. It is preferable to do so.

General formula (E)
-[CH ₂ -C (-R ₁ ) (-CO ₂ R ₂ )] _m- [CH _2- C (-R ₃ ) (-CO ₂ R ₄ -OH)-] _n
(In the formula, R ₁ , R ₃ , are H or CH ₃ , R ₂ , R ₄ are CH ₂ or C ₂ H ₄ or C ₃ H ₆ , m, n represent repeating units).
Since the compound represented by the general formula (E) used in the present invention has a weight average molecular weight in the range of 1000 to 30,000, it is considered to be between the oligomer and the low molecular weight polymer.

The compound represented by the general formula (E) is preferably a polymer obtained by copolymerizing a kind of the following ethylenically unsaturated monomer Xa and a kind of the following ethylenically unsaturated monomer Xb.

-(Xa) _m- (Xb) _n- (m and n represent repeating units)
The monomers as the monomer units constituting the compound represented by the general formula (E) are listed below, but are not limited thereto.

The ethylenically unsaturated monomer Xa may be, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), or pentyl acrylate (n-, i-, s-, t-). n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), nonyl acrylate (n-, i-) i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-ethoxyethyl), etc., or the above acrylic acid ester as a methacrylic acid ester. It can be mentioned that it was changed to. Of these, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and propyl methacrylate (i-, n-) are preferable.

The ethylenically unsaturated monomer Xb is preferably acrylic acid or methacrylic acid ester, for example, acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4). -Hydroxybutyl), acrylic acid (2-hydroxybutyl), or those in which these acrylic acids are replaced with methacrylic acid can be mentioned, preferably acrylic acid (2-hydroxyethyl) and methacrylic acid (2-hydroxyethyl). ), Acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl).

The molar composition ratio m: n of Xa and Xb is preferably in the range of 99: 1 to 65:35, more preferably in the range of 95: 5 to 75:25.

When the molar composition ratio of Xa is large, the compatibility with the cyclic polyolefin resin is improved, but the heat resistance of the film is lowered. If the molar composition ratio of Xb is large, the compatibility becomes poor. Further, if the molar composition ratio of Xb exceeds the above range, haze tends to occur during film formation, and it is preferable to optimize these and determine the molar composition ratio of Xa and Xb.

The weight average molecular weight of the compound represented by the general formula (E) is in the range of 1000 to 30,000, more preferably 8000 to 25000.

By setting the weight average molecular weight to 1000 or more and 30,000 or less, compatibility with the resin is further improved without evaporation or volatilization, which is preferable.

The weight average molecular weight can be measured by the following method.

(Weight average molecular weight measurement method)
The weight average molecular weight Mw was measured using gel permeation chromatography. The measurement conditions are as follows.

Solvent: Methylene chloride Column: Shodex K806, K805, K803G (Three from Showa Denko KK were connected and used)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Science)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0 ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (Tosoh Corporation)
A calibration curve with 13 samples from Mw = 500 to 1000000 was used. 13 samples are used at approximately equal intervals.

In order to synthesize the compound represented by the general formula (E), it is difficult to control the molecular weight by ordinary polymerization, and it is desirable to use a method capable of making the molecular weight as uniform as possible by a method that does not increase the molecular weight too much. Examples of such a polymerization method include a method using a peroxide polymerization initiator such as cumenperoxide and t-butylhydroperoxide, a method using a larger amount of the polymerization initiator than normal polymerization, a mercapto compound in addition to the polymerization initiator. , A method using a chain transfer agent such as carbon tetrachloride, a method using a polymerization terminator such as benzoquinone or dinitrobenzene in addition to the polymerization initiator, and JP-A-2000-128911 or 2000-344823. Examples thereof include a compound having one thiol group and a secondary hydroxy group as shown in the above, or a method of performing massive polymerization using a polymerization catalyst in which the compound and an organic metal compound are used in combination, all of which are the present invention. In particular, a polymerization method using a compound having a thiol group and a secondary hydroxy group in the molecule as a chain transfer agent is preferable.

In this case, the terminal of the compound represented by the general formula (E) has a hydroxy group and a thioether derived from the polymerization catalyst and the chain transfer agent. With this terminal residue, the compatibility between the compound represented by the general formula (E) and the polymer resin having an alicyclic structure can be adjusted.

The polymerization temperature is usually 30 ° C. to 130 ° C., preferably 50 to 100 ° C., but the molecular weight can be controlled by adjusting this temperature or the polymerization reaction time.

The hydroxy group value of the compound represented by the general formula (E) is preferably 30 to 150 [mgKOH / g].

(Measuring method of hydroxy value)
This measurement conforms to JIS K 0070 (1992). This hydroxy value is defined as the number of mg of potassium hydroxide required to neutralize the acetic acid bound to the hydroxy group when 1 g of the sample is acetylated. Specifically, Xg (about 1 g) of a sample is precisely weighed into a flask, and 20 ml of an acetylation reagent (20 ml of acetic anhydride to 400 ml) is accurately added. An air cooling tube is attached to the mouth of the flask and heated in a glycerin bath at 95 to 100 ° C.

After 1 hour and 30 minutes, the mixture is cooled, 1 ml of purified water is added from an air cooling tube, and acetic anhydride is decomposed into acetic acid. Next, titration is performed with a 0.5 mol / L potassium hydroxide ethanol solution using a potentiometric titrator, and the inflection point of the obtained titration curve is set as the end point. Furthermore, as a blank test, titration is performed without inserting a sample, and the inflection point of the titration curve is obtained.

The hydroxy value is calculated by the following formula.

Hydroxy value = {(BC) x f x 28.05 / X} + D
(In the formula, B is the amount of 0.5 mol / L potassium hydroxide ethanol solution used for the blank test (ml), and C is the amount of 0.5 mol / L potassium hydroxide ethanol solution used for titration (ml). , F is the factor of 0.5 mol / L potassium hydroxide ethanol solution, D is the acid value, and 28.05 is 1/2 of the 1 mol amount of potassium hydroxide 56.11.)
The compound represented by the general formula (E) needs to be contained in the cyclic polyolefin resin in an amount of 0.1 to 30% by mass, preferably 1 to 25% by mass, more preferably 3 to 20% by mass. Particularly preferably, it is 5 to 15% by mass.

(Acrylic resin manufacturing method)
As a method for producing the acrylic resin according to the present invention, a commonly used polymerization method such as cast polymerization, bulk polymerization, suspension polymerization, solution polymerization, emulsification polymerization, anion polymerization and the like can be used. Of these, bulk polymerization and solution polymerization that do not use suspending agents or emulsifiers are preferable because it is possible to reduce the mixing of minute foreign substances that are inconvenient for optical applications.

《Solution polymerization》
In the case of solution polymerization, a solution prepared by dissolving a mixture of monomers in a solvent of aromatic hydrocarbons such as toluene and ethylbenzene can be used. In the case of polymerization by bulk polymerization, the polymerization can be started by free radicals generated by heating or ionizing radiation irradiation as is usually performed.

As the initiator used in the polymerization reaction, any initiator used in radical polymerization can be used, and for example, an azo compound such as azobisisobutylnitrile; benzoyl peroxide, lauroyl peroxide, t-butyl peroxy. Organic peroxides such as -2-ethylhexanoate can be used.

In particular, when polymerization is carried out at a high temperature of 90 ° C. or higher, solution polymerization is common, so that a peroxide or azobis that has a 10-hour half-life temperature of 80 ° C. or higher and is soluble in the organic solvent used. Initiators and the like are preferred. Specifically, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, cyclohexaneperoxide, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 1 , 1-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) isobutyronitrile and the like can be mentioned. These initiators are preferably used, for example, in the range of 0.005 to 5% by mass with respect to 100% by mass of the total monomer.

As the molecular weight adjusting agent used as necessary in the polymerization reaction, any agent generally used in radical polymerization can be used, and for example, a mercaptan compound such as butyl mercaptan, octyl mercaptan, dodecyl mercaptan, and 2-ethylhexyl thioglycolate. Is particularly preferred. These molecular weight modifiers are added in a concentration range such that the molecular weight of the acrylic resin is controlled within the above-mentioned preferable range.

<< Bulk Polymerization >>
Bulk polymerization is carried out, for example, by continuously supplying a monomer component, a polymerization initiator and the like into a reaction vessel and continuously extracting a partial polymer obtained by retaining the monomer component and a polymerization initiator in the reaction vessel for a predetermined time. Therefore, the copolymer can be produced with high productivity.

The polymerization initiator used when polymerizing the monomer component is not particularly limited, and is, for example, an azo compound such as azobisisobutyronitrile, 1,1-di (tert-butylperoxy) cyclohexane. , Benzoyl peroxide, p-chlorobenzoyl peroxide, diisopropyl peroxy carbonate, di-2-ethylhexyl peroxy carbonate, t-butyl peroxypivalate, t-butyl peroxy (2-ethylhexanoate) and the like. Known radical polymerization initiators such as oxides can be used. The polymerization initiator may be used alone or in combination of two or more. The amount used is usually 0.01 to 5% by mass with respect to the total amount of the mixture. The heating temperature in thermal polymerization is usually 40 to 200 ° C., and the heating time is usually about 30 minutes to 8 hours.

When polymerizing the monomer component, a chain transfer agent can be used, if necessary. The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, and 2-ethylhexylthioglycolate. As the chain transfer agent, only one kind may be used, or two or more kinds may be used in combination.

《Suspension polymerization》
In the case of suspension polymerization, those used for ordinary suspension polymerization can be used, and examples thereof include organic peroxides and azo compounds.
Further, as the suspension stabilizer, commonly used known substances can be used, and examples thereof include organic colloidal polymer substances, inorganic colloidal polymer substances, inorganic fine particles, and combinations thereof with a surfactant. can.

Examples of the aqueous medium for polymerizing the monomer mixture include water or a mixed medium of water and a water-soluble solvent such as alcohol (eg, methanol, ethanol). The amount of the aqueous medium used is usually 100 to 1000 parts by mass with respect to 100 parts by mass of the monomer mixture in order to stabilize the crosslinked resin particles.
In addition, in order to suppress the generation of emulsified particles in an aqueous system, water-soluble polymerization inhibitors such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble B vitamins, citric acid, and polyphenols may be used. good.

Further, other suspension stabilizers may be added as needed. For example, phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, pyrophosphates such as calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, zinc pyrophosphate, calcium carbonate, magnesium carbonate, calcium hydroxide. , Magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate and other poorly water-soluble inorganic compounds, polyvinyl alcohol dispersion stabilizers and the like.

It is also possible to use the suspension stabilizer in combination with a surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric ionic surfactant, and a nonionic surfactant.

Examples of the anionic surfactant include fatty acid oils such as sodium oleate and potassium castor oil, alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, and alkylsulfonic acids. Salt, Alkylnaphthalene Sulfate, Alcan Sulfate, Succinate, Dialkylsulfosuccinate, Alkyl Phosphate Ester, Naphthalene Sulfate Formarin Condensate, Polyoxyethylene Alkylphenyl Ether Sulfate, Polyoxyethylene Alkyl Examples thereof include sulfate ester salts.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, and oxy. Examples thereof include ethylene-oxypropylene block polymer.

Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of the amphoteric ion surfactant include lauryldimethylamine oxide and a phosphate ester-based or phosphite ester-based surfactant.

These suspension stabilizers and surfactants may be used alone or in combination of two or more, but the suspension stabilizer may be selected in consideration of the diameter of the obtained particles and the dispersion stability during polymerization. It is used by adjusting the usage amount as appropriate. Usually, the amount of the suspension stabilizer added is 0.5 to 15 parts by mass with respect to 100 parts by mass of the monomer mixture, and the amount of the surfactant added is 0. It is 001 to 10 parts by mass.

The monomer mixture is added to the aqueous medium thus prepared to carry out the polymerization.

As a method for dispersing the monomer mixture, for example, a method in which the monomer mixture is directly added to the aqueous medium and dispersed in the aqueous medium as monomer droplets by the stirring force of a propeller blade or the like, high shear composed of a rotor and a stator. Examples thereof include a method of dispersing using a homomixer which is a disperser using force, an ultrasonic disperser, and the like.
The aqueous suspension in which the monomer mixture is dispersed as spherical droplets is then heated to initiate polymerization. During the polymerization reaction, it is preferable to stir the aqueous suspension, and the stirring may be performed slowly, for example, so as to prevent the floating of spherical droplets and the sedimentation of particles after polymerization.

The polymerization temperature is preferably about 30 to 100 ° C, more preferably about 40 to 80 ° C. The time for maintaining this polymerization temperature is preferably about 0.1 to 20 hours.

After the polymerization, the particles are separated as a hydrous cake by suction filtration, centrifugal dehydration, centrifugation, pressure dehydration, or the like, and the obtained hydrous cake is washed with water and dried to obtain the desired particles. Here, the average particle size of the particles is adjusted by adjusting the mixing conditions of the monomer mixture and water, the amount of suspension stabilizer, surfactant, etc. added, the stirring conditions of the stirrer, and the dispersion conditions. It is possible.

(Additives in acrylic resin)
Various additives may be contained in the acrylic resin which is the raw material of the acrylic resin film according to the present invention. It is usually preferable that various additives described below are usually contained for the purpose of preserving the monomer, controlling the polymerization reaction, and enhancing the preservability of the resin.

<< Polymerization initiator >>
As the polymerization initiator, as described in the above-mentioned solution polymerization, bulk polymerization and suspension polymerization, commonly used ones can be used, and examples thereof include peroxide-based polymerization initiators and azo-based polymerization initiators.
Specifically, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, orsochloroperoxide benzoyl, orthomethoxy peroxide benzoyl, methylethylketone peroxide, diisopropylperoxydicarbonate, cumenhydroperoxide, cyclohexanone peroxide, t-butyl. Hydrooxide-based polymerization initiators such as hydroperoxide and diisopropylbenzene hydroperoxide, asobisvaleronitrile, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile) ), 2,2'-Azobisisobuty (2,3-dimethylbutyronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,3,3-trimethylbutyronitrile) Nitrile), 2,2'-azobis (2-isopropylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvalero) Examples thereof include azo-based initiators such as nitrile, (2-carbamoylazo) isobutyronitrile, 4,4'-azobis (4-cyanovaleric acid), and dimethyl-2,2'-azobisisobutyrate.

Among these, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide and the like are the points of decomposition rate of the polymerization initiator. Is preferable.
The polymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, based on 100 parts by mass of the monomer mixture. If the amount of the polymerization initiator is less than 0.01 parts by mass, it is difficult to fulfill the function of initiating the polymerization, and if it is used in excess of 10 parts by mass, it is uneconomical in terms of cost, which is not preferable.

《Chain transfer agent》
Examples of the chain transfer agent include n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, ethylene glycol bisthiopropionate, butanediol bisthioglycolate. , Butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimethylpropanthris- (β-thiopropionate), pentaerythritol tetrakisthiopropionate and other alkyl mercaptans. And so on. Of these, monofunctional alkyl mercaptans such as n-octyl mercaptan and n-dodecyl mercaptan are preferable. These chain transfer agents can be used alone or in combination of two or more.

The amount of the chain transfer agent used is preferably in the range of 0.1 to 1 part by mass, more preferably in the range of 0.15 to 0.8 parts by mass with respect to 100 parts by mass of the monomer mixture. It is more preferably in the range of 0.2 to 0.6 parts by mass, and particularly preferably in the range of 0.2 to 0.5 parts by mass. The amount of the chain transfer agent used is preferably in the range of 2500 to 7000 parts by mass, more preferably in the range of 3500 to 4500 parts by mass, and further preferably in the range of 3800 to 4500 parts by mass with respect to 100 parts by mass of the polymerization initiator. It is in the range of 4300 parts by mass.

(Weight average molecular weight (Mw))
The weight average molecular weight of the acrylic resin according to the present invention is in the range of 300,000 to 4,000,000.
The weight average molecular weight can be obtained as follows.
The weight average molecular weight (Mw) of the acrylic resin according to the present invention is determined by polystyrene conversion according to the following measurement conditions using gel permeation chromatography (GPC).
Measurement system: "GPC system HLC-8220" manufactured by Tosoh Corporation
Developing solvent: Chloroform (manufactured by Wako Pure Chemical Industries; special grade)
Solvent flow rate: 0.6 mL / min Standard sample: TSK standard polystyrene (Tosoh "PS-oligomer kit")
Measurement side column configuration: Tosoh's "TSK-GEL super HZM-M 6.0x150" 2 series connection, Tosoh's "TSK-GEL super HZ-L 4.6x35" 1 reference side column configuration: Tosoh's "TSK-GEL SuperH-RC 6.0x150" 2 series connection Column temperature: 40 ° C

(Method of adjusting weight average molecular weight and molecular weight distribution)
The weight average molecular weight of the acrylic resin can be adjusted mainly by adjusting the amount of the chain transfer agent described later. It can also be adjusted by adjusting the polymerization temperature and the polymerization reaction time.
Similarly, the molecular weight distribution can be adjusted by the amount of the chain transfer agent, the polymerization temperature and the polymerization reaction time. Living radical polymerization (exemplified in Japanese Patent No. 3845109 and 4107996) is known as a method for extremely narrowing the molecular weight distribution. Further, as a method of widening the molecular weight distribution, it is convenient to blend resins having different molecular weights.
The weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) can be measured using gel permeation chromatography (GPC).

(Residual monomer)
At the stage of synthesizing the acrylic resin, an unreacted monomer component is contained in the acrylic resin as a residual monomer. As a method of reducing the amount of residual monomer, the reaction efficiency is basically increased to reduce the amount of unreacted monomer, but there is also a method of removing the residual monomer later.
Generally, devolatile by venting is carried out during extrusion with a high-temperature extruder, but the method is not limited to this, and the acrylic resin is washed by selecting a suitable solvent and a method of heating in an oven.・ A method of drying is conceivable.
The amount of the residual monomer in the acrylic resin is preferably in the range of 0.01 to 1% by mass, more preferably in the range of 0.01 to 0.1% by mass.

(Glass-transition temperature)
The Tg (glass transition temperature) of the acrylic resin according to the present invention is characterized in that it is in the range of 120 to 180 ° C.
Due to the recent demand for higher durability of optical films, durability at temperatures exceeding 100 ° C. (for example, 105 ° C.) has been tested. Therefore, the Tg of the acrylic resin according to the present invention is 120 ° C. or higher. It is necessary to be. The Tg of methyl polymethacrylate, which is a typical acrylic resin, is 105 to 115 ° C., which is not suitable for the present invention.

(Preparation method of glass transition temperature)
Efforts have been made to raise the Tg of acrylic resin, and specific examples thereof are shown below. Most of them have a partially cyclic structure introduced in the main chain in order to regulate the free rotation of the polymer main chain.

(Known high Tg acrylic resin)
《Lactone ring system》
By forming the lactone ring structure in the molecular chain of the polymer (the main skeleton of the polymer is also referred to as the main chain), high heat resistance is imparted to the acrylic resin which is the copolymer, and glass is used. This is preferable because the transition temperature (Tg) is also high. Further, from the viewpoint of improving heat resistance and suppressing bubbles and silver streaks during film production, it is preferable that the reaction rate of the cyclization condensation reaction leading to the lactone ring structure is sufficiently high.

The lactone ring unit used for copolymerization with the acrylic resin in the present invention is not particularly limited, but is limited to JP-A-2007-297615, JP-A-2007-63541, JP-A-2007-70607, and JP-A-2007-100044. No., JP-A-2007-254726, JP-A-2007-254727, JP-A-2007-261265, JP-A-2007-293272, JP-A-2007-297919, JP-A-2007-316366, JP-A-2008-9378 , Japanese Patent Application Laid-Open No. 2008-76764 and the like. It should be noted that these are not limited to the present invention, and these can be used alone or in combination of two or more.

The structure of the lactone ring unit in the main chain is preferably a 4- to 8-membered ring, more preferably a 5- to 6-membered ring, and particularly preferably a 6-membered ring from the viewpoint of structural stability. When the structure of the lactone ring unit in the main chain is a 6-membered ring, the structure represented by the following general formula (2), the structure represented by JP-A-2004-168882, and the like can be mentioned. The point that the polymerization yield is high in synthesizing the polymer before introducing the structure of the lactone ring unit, the point that it is easy to obtain the polymer with a high content ratio of the lactone ring structure in the high polymerization yield, methyl methacrylate, etc. The structure represented by the following general formula (2) is particularly preferable in that it has good copolymerizability with the (meth) acrylic acid ester.

In the general formula (2), R ^{11 to} R ¹³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.

The organic residue is not particularly limited as long as it has 1 to 20 carbon atoms, and is, for example, a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, or a −OAc group. , -CN groups and the like. Further, the organic residue may contain an oxygen atom.
The carbon number of R ^{11 to} R ¹³ is preferably 1 to 10, and more preferably 1 to 5.

The method for producing the lactone ring unit-containing acrylic resin is not particularly limited, but preferably, the obtained polymer is heated after obtaining a polymer having a hydroxy group and an ester group in the molecular chain by a polymerization step. A lactone ring-containing polymer can be obtained by performing a lactone cyclization condensation step of introducing a lactone ring structure into the polymer by the treatment.

<< Maleic anhydride type >>
By forming the maleic anhydride structure in the molecular chain of the polymer (in the main skeleton of the polymer), high heat resistance is imparted to the acrylic resin which is a copolymer, and the glass transition temperature (Tg) is also high. It is preferable because it becomes expensive.

The maleic anhydride unit used for the copolymerization with the acrylic resin is not particularly limited, but is not particularly limited, but is JP-A-2007-113109, JP-A-2003-292714, JP-A-6-279546, JP-A-2007-51233. No., JP-A-2001-270905, JP-A-2002-167964, JP-A-2000-302988, JP-A-2007-113110, JP-A-2007-11565, and maleic anhydride-modified resins. Can be mentioned. It should be noted that these do not limit the present invention.
Among these, the resin described in JP-A-2007-113109 and the maleic acid-modified MAS resin (methyl methacrylate-acrylonitrile-styrene copolymer, for example, Delpet 980N manufactured by Asahi Kasei Chemicals Co., Ltd.) can be preferably used. .. It should be noted that these are not limited to the present invention, and these can be used alone or in combination of two or more. Further, the method for producing an acrylic resin containing a maleic anhydride unit is not particularly limited, and a known method can be used.

The maleic anhydride-modified resin is not limited as long as the obtained polymer contains a maleic anhydride unit. For example, (anhydrous) maleic acid-modified MS resin and (anhydrous) maleic acid-modified MAS resin (methacrylic acid). Methyl-acrylonitrile-styrene copolymer), (anhydrous) maleic acid-modified MBS resin, (anhydrous) maleic acid-modified AS resin, (anhydrous) maleic acid-modified AA resin, (anhydrous) maleic acid-modified ABS resin, ethylene-maleic anhydride Examples thereof include an acid copolymer, an ethylene- (meth) acrylic acid-maleic anhydride copolymer, and a maleic anhydride graft polypropylene.
The maleic anhydride unit has a structure represented by the following general formula (3).

In the general formula (3), R ²¹ and R ²² each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.
The organic residue is not particularly limited as long as it has 1 to 20 carbon atoms, and is, for example, a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, or a −OAc group. , -CN groups and the like. Further, the organic residue may contain an oxygen atom.
The carbon atoms of R ²¹ and R ²² are preferably 1 to 10, and more preferably 1 to 5.

When R ²¹ and R ²² each represent a hydrogen atom, it is also preferable to further contain other copolymerization components from the viewpoint of adjusting the intrinsic birefringence. As such a ternary or higher heat-resistant acrylic resin, for example, a methyl methacrylate-maleic anhydride-styrene copolymer can be preferably used.

《Glutaric anhydride system》
By forming the glutaric anhydride structure in the molecular chain of the polymer (in the main skeleton of the polymer), high heat resistance is imparted to the acrylic resin which is a copolymer, and the glass transition temperature (Tg). Is preferable because it also increases.
The maleic anhydride unit used for copolymerization with the acrylic resin in the present invention is not particularly limited, but is not particularly limited, but JP-A-2006-241263, JP-A-2004-702290, JP-A-2004-70296, JP-A-2004. -126546, JP-A-2004-163924, JP-A-2004-291302, JP-A-2004-292812, JP-A-2005-314534, JP-A-2005-326613, JP-A-2005-331728, JP-A-2006- 131898, Japanese Patent Laid-Open No. 2006-134872, Japanese Patent Laid-Open No. 2006-206881, JP-A-2006-241197, JP-A-2006-283013, JP-A-2007-118266, JP-A-2007-176982, JP-A-2007-178504 No., JP-A-2007-197703, JP-A-2008-74918, WO2005 / 105918 and the like can be used.
Of these, the one described in JP-A-2008-74918 is more preferable. It should be noted that these are not limited to the present invention, and these can be used alone or in combination of two or more.

The glutaric anhydride unit has a structure represented by the following general formula (4).

In the general formula (4), R ³¹ and R ³² represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.
The carbon atoms of R ³¹ and R ³² are preferably 1 to 10, and more preferably 1 to 5.

The acrylic resin containing such a glutaric acid anhydride unit is obtained by forming an unsaturated carboxylic acid monomer and an unsaturated carboxylic acid alkyl ester monomer that give the glutaric acid anhydride unit into a copolymer, and then forming the same weight. It can be produced by heating the coalescence in the presence or absence of a suitable catalyst to carry out an intramolecular cyclization reaction by dealcoholization and / or dehydration.

《Glutarimide system》
The acrylic resin having glutarimide as a ring structure is a resin containing a glutarimide unit represented by the following general formula (1a).

(Here, R ¹ and R ² independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ³ is an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or carbon. The number 6 to 10 aryl groups are shown.)

The method for producing an acrylic resin having glutarimide is not particularly limited, and a known method can be applied. Specifically, an imidization step of using polymethyl methacrylate or a methyl methacrylate-styrene copolymer as a raw material and treating with an imidizing agent, and an esterification step of treating with an esterifying agent as necessary. Then, an acrylic resin having glutarimide can be produced.

The imidizing agent is not particularly limited as long as it can produce glutarimide represented by the general formula (1a), and examples thereof include the compounds described in WO2005 / 054311. Among these imidizing agents, it is preferable to use methylamine, ammonia, cyclohexylamine, and aniline from the viewpoints of both cost and physical properties, and it is particularly preferable to use methylamine.

Methylamine, which is gaseous at room temperature, may be used in a state of being dissolved in alcohols such as methanol.
In this imidization step, the ratio of the glutarimide unit and the (meth) acrylic acid ester unit in the obtained acrylic resin can be adjusted by adjusting the addition ratio of the imidizing agent.

Specific examples of the imidization step include known methods such as those described in JP-A-2008-273140 and JP-A-2008-274187.

《Maleimide system》
By forming the maleimide-based structure in the molecular chain of the polymer (in the main skeleton of the polymer), high heat resistance is imparted to the acrylic resin which is a copolymer, and the glass transition temperature (Tg) is also high. Therefore, it is preferable. As the maleimide-based structural unit, the monomer represented by the following general formula (2a) is preferably used.

_{R 3} in the general formula (2a) is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms. It represents any of these and may have a substituent on the carbon atom.

The monomer for forming the maleimide-based structural unit is not particularly limited, but for example, maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide; N-phenylmaleimide, N- Methylphenylmaleimide, N-ethylphenylmaleimide, N-butylphenylmaleimide, N-dimethylphenylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N- (o-chlorophenyl) maleimide, N- (m-chlorophenyl) Examples thereof include N-aryl group-substituted maleimides such as maleimide and N- (p-chlorophenyl) maleimide.

From the viewpoint of imparting heat resistance and moisture heat resistance, N-cyclohexylmaleimide, N-phenylmaleimide, N-methylphenylmaleimide, N- (o-chlorophenyl) maleimide, N- (m-chlorophenyl) maleimide, N- ( p-Chlorophenyl) maleimide is mentioned, and N-cyclohexylmaleimide and N-phenylmaleimide are more preferable, and N-phenylmaleimide is more preferable, from the viewpoint of easy availability and heat resistance.

《Hydride of styrene copolymer》
By forming the hydride of the styrene copolymer in the molecular chain of the polymer (in the main skeleton of the polymer), high heat resistance is imparted to the acrylic resin, and the glass transition temperature (Tg) is also high. Therefore, it is preferable.
The hydride of the styrene copolymer according to the present invention is obtained by polymerizing a (meth) acrylic acid ester monomer and an aromatic vinyl monomer to obtain a thermoplastic resin (B0), and then the aromatic in the thermoplastic resin (B0). It is obtained by hydrogenating 70% or more of the aromatic double bonds in the constituent unit derived from the vinyl monomer.

The solvent used for the hydrogenation reaction is, for example, a hydrocarbon solvent such as cyclohexane or methylcyclohexane, an ester solvent such as ethyl acetate or methyl isobutyrate, a ketone solvent such as acetone or methyl ethyl ketone, or an ether such as tetrahydrofuran or dioxane. Examples thereof include a system solvent, an alcohol solvent such as methanol and isopropanol, and the like.

The method of hydrogenation is not particularly limited, and a known method can be used. For example, it can be carried out by a batch method or a continuous flow method at a hydrogen pressure of 3 to 30 MPa and a reaction temperature of 60 to 250 ° C. When the temperature is 60 ° C. or higher, the reaction time does not take too long, and when the temperature is 250 ° C. or lower, the molecular chain is less likely to be cleaved or the ester site is hydrogenated.

Examples of the catalyst used in the hydride reaction include metals such as nickel, palladium, platinum, cobalt, ruthenium, and rhodium, or oxides, salts, or complex compounds of these metals, and carbon, alumina, silica, silica-alumina, and diatomaceous earth. Examples thereof include a solid catalyst carried on a porous carrier such as.

The hydride of the styrene copolymer is obtained by hydrogenating 70% or more of the aromatic double bonds in the structural unit derived from the aromatic vinyl monomer in the thermoplastic resin (B0). That is, the proportion of the aromatic double bond remaining in the structural unit derived from the aromatic vinyl monomer is 30% or less, preferably in the range of less than 10%, and more preferably in the range of less than 5%.

(Higher-order structure)
《Three-dimensional regularity》
Any steric regularity of the acrylic resin according to the present invention can be selected.
As described in JP-A-2017-48344, in the chain of structural units (doubles, diads) in a polymer molecule, those having the same configuration are referred to as meso, and those having the same configuration are referred to as racemo, respectively. Notated as m and r. The ratio of the two chains (doubles, diad) of the chain of three consecutive structural units (triple, triad) being racemic (denoted as rr) is the syndiotacticity of triplet display. City (rr) (hereinafter, simply referred to as "Syngio Tacticity (rr)").
In the present invention, an acrylic resin having a triplet display syndiotacticity (rr) of 53 to 57%, preferably 54 to 56% may be selected.
A method for producing a polymer of an unsaturated carboxylic acid and a derivative thereof disclosed in JP-A-2002-145914 by radical polymerization, and an inexpensive method capable of effectively controlling the stereoregularity of the obtained polymer is also preferable. Can be carried out.

《Block Copolymer》
As the acrylic resin according to the present invention, the block copolymer disclosed in JP-A-2018-24794 etc. is also preferably selected. The block is preferably composed of a block having a relatively high Tg that enhances heat resistance and a block having a relatively low Tg that enhances flexibility. Further, the block copolymer may form not all of the acrylic resin according to the present invention but a part of the resin blend.

The method for producing the block copolymer is not particularly limited, and a method according to a known method can be adopted. For example, a method of living-polymerizing the monomers constituting each block is generally used. As such a living polymerization method, for example, a method of anion polymerization in the presence of a mineral acid such as an alkali metal or an alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator (Japanese Patent Publication No. 7-25859). (See), a method of anion polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound (see JP-A-11-335432), and a method of polymerizing an organic rare earth metal complex as a polymerization initiator (specially. Kaihei 6-93060 (see), Method of radical polymerization in the presence of a copper compound using an α-halogenated ester compound as an initiator (Macromol. Chem. Phys.) Vol. 201, pp. 1108-1114. (2000).) And so on.
Further, a method of polymerizing the monomers constituting each block using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent to produce a mixture containing the acrylic block copolymer according to the present invention is also mentioned. Be done. Among these methods, in particular, since an acrylic block copolymer can be obtained with high purity, its molecular weight and composition ratio can be easily controlled, and it is economical, an organoalkali metal compound is used as a polymerization initiator and is organic. A method of anionic polymerization in the presence of an aluminum compound is recommended.

《Branch structure》
As the acrylic resin according to the present invention, a polymer having a branched structure can be selected. The branched structure has a repeating structural unit not only in the polymer main chain but also in the side chain. A polymer having a branched structure is preferably selected for improving physical properties because the entanglement of polymer chains increases.
As a means for introducing a branched structure into the polymer, it is common to use a macromonomer corresponding to the side chain structure.

Examples of the macromonomer include a compound in which a methacryloyloxy group is added to the end of a methyl methacrylate polymer.
Such a macromonomer can be prepared by, for example, a method of attaching a polymerizable functional group to the terminal of the prepolymer (see JP-A-60-133007). Further, as the macromonomer, a commercially available one can also be used.

<< Cross-linking structure >>
A crosslinked structure may be introduced into the acrylic resin according to the present invention. One of the cross-linking methods is to use a polyfunctional monomer when polymerizing the acrylic resin. Another method is to incorporate reactive groups into the polymer side chains of the acrylic resin and crosslink the reactive groups with a cross-linking agent or by self-cross-linking.
By introducing a crosslinked structure, it is possible to improve the heat resistance and mechanical properties of the acrylic resin.

Examples of the crosslinkable monomer include a polyfunctional acrylic monomer, a polyfunctional allylic monomer, and a mixed monomer thereof.
Further, to give a specific example, for example, examples of the polyfunctional acrylic monomer include ethylene oxide-modified bisphenol A di (meth) acrylate, 1,4-butanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, and dipentaerythritol hexa. Acrylate, Dipentaerythritol Monohydroxypentaacrylate, Caprolactone-modified Dipentaerythritol Hexaacrylate, Pentaerythritol tri (meth) acrylate, Pentaerythritol tetra (meth) acrylate, Polyethylene glycol di (meth) acrylate, Trimethylol propanetriacrylate, EO-modified Trimethylol propanetri (meth) acrylates, PO-modified trimethylol propanetri (meth) acrylates, tris (acryloxyethyl) isocyanurates, tris (methacryloxyethyl) isocyanurates and mixtures thereof are common. In particular, tris (acryloxyethyl) isocyanurate (triacrylic acid ester of tris (2-hydroxyethyl) isocyanuric acid) has low skin irritation and can be preferably used.

Examples of the polyfunctional allyl-based monomer include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallylbenzene phosphonate and mixtures thereof, and examples thereof include triallyl cyanurate, triallyl isocyanurate and these. Mixtures are preferably used.

(Birerefringence (photoelastic coefficient, intrinsic birefringence))
It is preferable that the acrylic resin film according to the present invention has a low absolute value in both the photoelastic coefficient and the orientation birefringence (unique birefringence). The value of the in-plane retardation obtained by multiplying the orientation birefringence and the film thickness is preferably in the range of -20 nm to +20 nm or -5 nm to +5 nm. The value of the photoelastic coefficient is preferably in the range of ^{-20 × 10 -12} to +20 × ^10-12 Pa ^-1 , or -5 × 10 ^-12 to +5 × 10 ^-12 Pa ^-1.

The "photoelastic coefficient" in the present application is a coefficient representing the susceptibility of a change in birefringence due to an external force, and is defined by the following equation.
CR [/ Pa] = Δn / σR
Here, σR is the elongation stress [Pa], Δn is the birefringence at the time of stress application, and Δn is defined by the following equation.
Δn = n1-n2
Here, n1 is the refractive index in the direction parallel to the stretching direction, and n2 is the refractive index in the direction perpendicular to the stretching direction.

The closer the value of the photoelasticity coefficient is to zero, the smaller the change in birefringence due to external force is, which means that the birefringence designed for each application is less likely to change due to external force.
In the present invention, the monomer having a positive (negative) photoelasticity coefficient means a monomer having a positive (negative) photoelasticity coefficient of the homopolymer of the monomer.

Further, the "inherent birefringence" in the present application is a value representing the magnitude of birefringence depending on the orientation, and is defined by the following equation.
Intrinsic birefringence = npr-nvt
Here, npr is the refractive index in the direction parallel to the orientation direction of the polymer oriented in a uniaxial order, and nvt is the refractive index in the direction perpendicular to the orientation direction.
In the present invention, the monomer having a negative intrinsic birefringence is the orientation direction when light is incident on a layer formed by orienting a homopolymer of the monomer in a uniaxial order. A monomer whose refractive index of light is smaller than that of light in a direction orthogonal to the orientation direction.

The acrylic resin film according to the present invention has a unit (a) of 5% by mass or more and less than 85% by mass, which is derived from a monomer having a positive photoelastic coefficient and a negative intrinsic birefringence, and has a negative photoelastic coefficient. Unit (b) derived from a monomer having a negative intrinsic birefringence contains 5% by mass or more and less than 85% by mass, and 10% by mass or more and 50% by mass or less of the unit (c) having a 5- or 6-membered ring structure. It is preferable to contain the copolymer (1).

The unit (a) may be any unit as long as it is a unit derived from a monomer that satisfies the condition that the photoelastic coefficient is positive and the intrinsic birefringence is negative.
Examples of the monomer having a positive photoelastic coefficient and a negative intrinsic birefringence include aromatic vinyl compound units. Here, the aromatic vinyl compound refers to a compound having a styrene skeleton in its structure.

Specific examples of the aromatic vinyl compound include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, and the like. Nuclear alkyl-substituted styrenes such as 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, о-ethylstyrene, p-tert-butylstyrene; 1,1-diphenylethylene and the like are typical examples. The thing is styrene.
These aromatic vinyl compounds may be used alone or in combination of two or more.

The unit (b) may be any unit as long as it is a unit derived from a monomer that satisfies the condition that the photoelastic coefficient is negative and the intrinsic birefringence is negative. Examples of the monomer having a negative photoelastic coefficient and a negative intrinsic birefringence include (meth) acrylic monomers.

Here, the (meth) acrylic monomer refers to methacrylic acid, acrylic acid, and derivatives thereof, and is preferably a methacrylic acid ester and an acrylic acid ester.
Specific examples of the methacrylic acid ester include butyl methacrylate, ethyl methacrylate, methyl methacrylate, propyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-ethylhexyl methacrylate, t-butylcyclohexyl methacrylate, and benzyl methacrylate. Examples thereof include 2,2,2-trifluoroethyl methacrylate, and a typical one is methyl methacrylate.
Specific examples of the acrylate ester include methyl acrylate, ethyl acrylate, butyl acrylate, isopropyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and phenyl acrylate.

The copolymer containing an acrylic acid alkyl ester unit has excellent heat-decomposability and enhances fluidity during molding. Therefore, it is preferable to use an acrylic acid alkyl ester as the (meth) acrylic monomer in order to improve the heat-decomposability and molding processability. In this case, the amount of the acrylic acid alkyl ester unit used is preferably 0.1% by mass or more from the viewpoint of heat resistance, and preferably 15% by mass or less from the viewpoint of heat resistance. It is more preferably in the range of 0.2 to 14% by mass, and particularly preferably in the range of 1 to 12% by mass. Among the acrylic acid alkyl ester monomers, methyl acrylate and ethyl acrylate are remarkably preferable for the above-mentioned improving effect even if they are copolymerized in a small amount.
On the other hand, in order to improve the heat resistance, it is preferable to use a methacrylic acid ester as the (meth) acrylic monomer.

The above (meth) acrylic monomers may be used alone or in combination of two or more.

The unit (c) may be any unit as long as it has a 5- or 6-membered ring in its structure.
The unit (c) is, for example, an unsaturated dicarboxylic acid anhydride monomer unit which is an anhydride such as maleic anhydride or glutaric acid; an unsaturated carboxylic acid unit such as a lactone ring structure; N-phenylmaleimide, N- Maleimide units such as cyclohexylmaleimide and the like can be mentioned.

The contents of the unit (a), the unit (b), and the unit (c) are 5% by mass or more and less than 85% by mass, 5% by mass or more and less than 85% by mass, and more than 10% by mass and 50% by mass or less, respectively. Is preferable.
By setting the ratio of each unit constituting the copolymer (1) in such a range, the acrylic resin film according to the present invention is less likely to have in-plane retardation (Re), and the value of in-plane retardation is reduced. Can be strictly controlled.
Further, when the ratio of each unit constituting the copolymer (1) satisfies a specific relationship, that is, when the value of K represented by the following formula is 3.1 or more and 3.1 or less, the copolymer is used. The absolute value of the photoelastic coefficient of the polymer (1) is particularly small.
The value of K is more preferably 3-1 to 0, and even more preferably 3-1 to −1.0.

K = 7 × (A / 100) + (-6) × (B / 100) + 4 × (C / 100)
In the formula, A, B, and C represent the ratios (mass%) of the units (a), (b), and (c) in the copolymer (1), respectively.

(Resin blend)
The acrylic resin according to the present invention may be blended with a resin other than acrylic. The blend ratio is preferably in the range of 1 to 45% by mass with respect to the entire acrylic resin. Preferred resins for blending include, for example, cellulose ester resin, polyvinyl acetal resin, and styrene resin.

《Cellulose ester resin》
The cellulose ester resin may be substituted with either an aliphatic acyl group or an aromatic acyl group, but is preferably substituted with an acetyl group.

When the cellulose ester resin is an ester with an aliphatic acyl group, the aliphatic acyl group has 2 to 20 carbon atoms and specifically, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, and the like. Examples thereof include lauroyl and stearoyl.
In the present invention, the aliphatic acyl group further includes a group having a substituent, and the substituent is a substituent of the benzene ring when the aromatic ring is a benzene ring in the above-mentioned aromatic acyl group. Examples are given as.

When the cellulose ester resin is an ester with an aromatic acyl group, the number of substituents substituted on the aromatic ring is 0 or 1 to 5, preferably 1 to 3, and particularly preferably 1. Or two.
Furthermore, when the number of substituents substituted on the aromatic ring is two or more, they may be the same or different from each other, but they may be linked to each other and condensed polycyclic compounds (for example, naphthalene, indene, indane, phenanthrene, quinoline). , Isoquinoline, chromen, chroman, phthalazine, acridine, indole, indole, etc.) may be formed.

The cellulose ester resin has a structure in which at least one of a substituted or unsubstituted aliphatic acyl group and a substituted or unsubstituted aromatic acyl group is selected, which is used as the structure used for the cellulose resin according to the present invention. These may be cellulose alone or mixed acid esters.

As for the degree of substitution of the cellulose ester resin, the total degree of substitution (T) of the acyl group is 2.00 to 3.00, the acetyl group is not always necessary, and the degree of substitution of the acetyl group (ac) is 0 to 1.89. Is. More preferably, the degree of substitution (r) of the acyl group other than the acetyl group is 2.00 to 2.89.
The acyl group other than the acetyl group preferably has 3 to 7 carbon atoms.

In the cellulose ester resin, those having an acyl group having 2 to 7 carbon atoms as a substituent, that is, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate benzoate, And at least one selected from cellulose benzoates.
Among these, particularly preferable cellulose ester resin includes cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate and cellulose acetate butyrate.
The mixed fatty acid is more preferably a lower fatty acid ester of cellulose acetate propionate or cellulose acetate butyrate, and preferably has an acyl group having 2 to 4 carbon atoms as a substituent.
The moiety not substituted with the acyl group is usually present as a hydroxy group. These can be synthesized by a known method.
The degree of substitution of the acetyl group and the degree of substitution of other acyl groups were determined by the method specified in ASTM-D817-96.

If the weight average molecular weight (Mw) of the cellulose ester resin is 75,000 or more, the object of the present invention can be achieved even if it is about 1,000,000, but in consideration of productivity, 75,000 to 280000 are used. It is preferable, and the one of 100,000 to 240000 is more preferable. This weight average molecular weight can be measured by the GPC method.
Cellulose ester resins are commercially available from Daicel Corporation and Eastman Chemical Company. A particularly preferred cellulose ester resin is Eastman ^TM Cellulose Actate Propionate (CAP-482-20).

<< Polyvinyl acetal resin >>
The polyvinyl acetal resin used in the present invention can be obtained by acetalizing a polyvinyl alcohol resin with an aldehyde.
The polyvinyl alcohol resin used for producing the polyvinyl acetal resin has a viscosity average degree of polymerization in the range of 200 to 4000, preferably 300 to 3000, and more preferably 500 to 2000.
When the viscosity average degree of polymerization of the polyvinyl alcohol resin is less than 200, the mechanical properties of the obtained polyvinyl acetal resin are insufficient, and the mechanical properties of the acrylic resin film of the present invention, particularly toughness, tend to be insufficient, and the handling of the film tends to be insufficient. It tends to be bad. On the other hand, when the viscosity average degree of polymerization of the polyvinyl alcohol resin exceeds 4000, the melt viscosity at the time of melt-kneading with the methacrylic resin becomes high, and the production tends to be difficult.

Examples of the aldehyde having 3 or less carbon atoms used in the production of the polyvinyl acetal resin include formaldehyde (including paraformaldehyde), acetaldehyde (including paraacetaldehyde), propionaldehyde and the like. These aldehydes having 3 or less carbon atoms can be used alone or in combination of two or more. Among these aldehydes having 3 or less carbon atoms, acetaldehyde (including paraacetaldehyde) and formaldehyde (including paraformaldehyde) are preferable, and acetaldehyde is particularly preferable, from the viewpoint of ease of production.

Aldehydes having 4 or more carbon atoms used in the production of polyvinyl acetal resin include butyl aldehyde, n-octyl aldehyde, amyl aldehyde, hexyl aldehyde, heptyl aldehyde, 2-ethylhexyl aldehyde, cyclohexyl aldehyde, furfural, glioxal, glutaaldehyde, and benzaldehyde. , 2-Methylbenzaldehyde, 3-Methylbenzaldehyde, 4-Methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde and the like. These aldehydes having 4 or more carbon atoms may be used alone or in combination of two or more. Of these aldehydes, those containing butyraldehyde as a main component are preferable from the viewpoint of ease of production, and butyraldehyde is particularly preferable.

《Styrene resin》
In the present invention, the styrene-based resin means a polymer containing at least a styrene-based monomer as a monomer component. Here, the styrene-based monomer means a monomer having a styrene skeleton in its structure.
The styrene-based monomer is not particularly limited as long as it has a styrene skeleton in its structure, and is, for example, styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4. -Nuclear alkyl substituted styrene such as dimethylstyrene, ethylstyrene, p-tert-butylstyrene; aromatic vinyl compound monomers such as α-alkylsubstituted styrene such as α-methylstyrene and α-methyl-p-methylstyrene. Among them, styrene is preferable.

The styrene-based resin may be a homopolymer of the styrene-based monomer or a copolymer of the styrene-based monomer and other monomer components. Examples of the monomer component that can be copolymerized with the styrene-based monomer include alkyl methacrylate monomers such as methyl methacrylate, cyclohexyl methacrylate, methyl phenyl methacrylate, and isopropyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. , Unsaturated carboxylic acid alkyl ester monomer such as alkyl acrylate monomer such as cyclohexyl acrylate; unsaturated carboxylic acid monomer such as methacrylic acid, acrylic acid, itaconic acid, maleic acid, fumaric acid, cinnamic acid; anhydrous Unsaturated dicarboxylic acid anhydride monomer which is an anhydride such as maleic acid, itaconic acid, ethylmaleic acid, methylitaconic acid, chlormaleic acid; unsaturated nitrile monomer such as acrylonitrile and methacrylonitrile; 1,3 Examples thereof include conjugated diene monomers such as −butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. , Two or more of these may be copolymerized. The copolymerization ratio of such other monomer components is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less with respect to the styrene-based monomer.

As styrene-based resins, styrene-acrylonitrile copolymer, styrene-methacrylic acid copolymer, and styrene-maleic anhydride copolymer are particularly excellent in terms of properties required for optical materials such as heat resistance and transparency. Therefore, it is preferable.
In the case of the styrene-acrylonitrile copolymer, the copolymerization ratio of acrylonitrile in the copolymer is preferably 1 to 40% by mass, more preferably 1 to 30% by mass, and further preferably 1 to 25% by mass. Is. When the copolymerization ratio of acrylonitrile in the copolymer is in the range of 1 to 40% by mass, it is preferable because a copolymer having excellent transparency tends to be obtained.

In the case of the styrene-methacrylic acid copolymer, the copolymerization ratio of methacrylic acid in the copolymer is preferably 0.1 to 50% by mass, more preferably 0.1 to 40% by mass, and further preferably. Is 0.1 to 30% by mass. When the copolymerization ratio of methacrylic acid in the copolymer is 0.1% by mass or more, a copolymer having excellent heat resistance tends to be obtained, and when it is 50% by mass or less, the copolymer weight having excellent transparency tends to be obtained. It is preferable because it tends to be coalesced.

In the case of the styrene-maleic anhydride copolymer, the copolymerization ratio of maleic anhydride in the copolymer is preferably 0.1 to 50% by mass, more preferably 0.1 to 40% by mass. More preferably, it is 0.1 to 30% by mass. When the copolymerization ratio of maleic anhydride in the copolymer is 0.1% by mass or more, a copolymer having excellent heat resistance tends to be obtained, and when it is 50% by mass or less, a copolymer having excellent transparency tends to be obtained. It is preferable because a polymer tends to be obtained.

(2) Rubber particles There are various intentions to use fine particles in the film, and there are so-called matting agents that impart irregularities to the surface of the film to improve slipperiness, phase difference controlled fine particles using birefringence of crystalline fine particles, and the like. .. In the present invention, in addition to these, rubber particles, also called elastic fine particles, are used to impart supple flexibility to the brittle and fragile acrylic resin film. The fine particles of the present invention include both a matting agent and rubber particles, but first, the rubber particles will be described here.
The acrylic resin film according to the present invention is characterized by containing rubber particles having a core-shell structure (multilayer structure). It may be a two-layer composed of a core layer and a shell layer, a three-layer structure of a core layer / an intermediate layer / a shell layer, and a three-layer structure of a seed particle layer / a core layer / a shell layer. However, the shell layer is the outermost layer.
As is conventionally known, toughness can be imparted by adding rubber particles which are elastic bodies to a brittle acrylic resin film. The rubber particle content in the acrylic resin film is preferably 1 to 45% by mass, more preferably 5 to 35% by mass, and most preferably 5 to 20% by mass.

(Layer structure of rubber particles)
The rubber particles are a multilayer composed of a core portion and a shell portion obtained by further polymerizing a (meth) acrylic acid ester as a shell portion on a particulate polymer which is a core portion having an average particle diameter in the range of 0.01 to 1 μm. Has a structure.
The rubber particles have a structure derived from a polyfunctional compound only in the central portion (core), and the portion (shell) surrounding the central portion has high compatibility with the acrylic resin constituting the acrylic resin film. It is preferable to have a structure. As a result, the rubber particles can be more uniformly dispersed in the acrylic resin, and by-products of foreign substances generated by the aggregation of the rubber particles can be further suppressed.
Hereinafter, the shell portion and the core portion of the core-shell structure will be described.

《Shell part》
The shell portion is not particularly limited as long as it has a structure having high compatibility with the acrylic resin constituting the acrylic resin film.

《Core part》
The core portion is not particularly limited as long as it has a structure that exhibits the effect of improving the flexibility of the acrylic resin constituting the acrylic resin film, and examples thereof include a structure having a crosslink. Further, the structure having crosslinks is preferably a crosslinked rubber structure.
The crosslinked rubber structure is a rubber having a polymer whose glass transition point is in the range of -100 ° C to 25 ° C as a main chain and having elasticity by cross-linking between the main chains with a polyfunctional compound. Means the structure of. Examples of the crosslinked rubber structure include acrylic rubber, polybutadiene rubber, and olefin rubber structures (repeated structural units). Among these, acrylic rubber is preferable because it is easy to control the average particle size to 0.3 μm or less and the optical properties such as transparency of the film are good when uniformly dispersed in the resin.

Examples of the structure having a crosslink include a structure derived from the above-mentioned polyfunctional compound. Among the polyfunctional compounds, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, divinylbenzene, allyl methacrylate, allyl acrylate, and dicyclopentenyl methacrylate are more preferable.
The amount of the polyfunctional monomer used in the production of the core portion is preferably in the range of 0.01 to 15% by mass, preferably in the range of 0.1 to 10% by mass of the monomer composition used. It is more preferable to be inside. By using the polyfunctional monomer within the above range, the obtained film exhibits good bending resistance.

(Constituent materials)
Examples of the material of the rubber particles include a butadiene-based crosslinked polymer, a (meth) acrylic-based crosslinked polymer, an organosiloxane-based crosslinked polymer, and the like. Above all, in terms of weather resistance (light resistance) and transparency of the film, the (meth) acrylic crosslinked polymer (in the present specification, the rubber portion made of the (meth) acrylic copolymer is also referred to as acrylic rubber particles. Is particularly preferable.

Examples of the acrylic rubber particles include ABS resin rubber particles, ASA resin rubber particles, and acrylic acid ester rubber particles.
As the multilayer structure particles, multilayer structure particles obtained by performing graft polymerization on the surface of these acrylic rubber particles using a desired monomer to form a shell layer are preferable.
From the viewpoint of the transparency of the obtained film, the acrylic graft copolymer particles obtained by performing graft polymerization on the surface of the particles of the acrylic acid ester rubber-like polymer shown below are preferable as the multilayer structure particles. ..
The acrylic graft copolymer particles can be obtained by polymerizing a monomer mixture containing a methacrylic acid ester as a main component in the presence of particles of an acrylic acid ester-based rubber-like polymer.

《Single sensuality》
The acrylic acid ester-based rubber-like polymer, which is the material of the rubber portion, is a rubber-like polymer containing acrylic acid ester as a main component. Specifically, a monomer mixture (100% by mass) consisting of 50 to 100% by mass of acrylic acid ester and 50 to 0% by mass of other copolymerizable vinyl-based monomers, and two or more per molecule. It is preferably obtained by polymerizing a polyfunctional monomer having a non-conjugated reactive double bond.
The polyfunctional monomer is used in a desired amount so that the degree of cross-linking of the rubber portion is in the range of 2.3 to 4.0% by mass.
All the monomers may be mixed and used, or the monomer composition may be changed and used in two or more stages.

As the acrylic acid ester, it is preferable to use an alkyl group having 1 to 12 carbon atoms from the viewpoint of polymerizability and cost. For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, benzyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n- acrylate. Examples thereof include octyl, phenyl acrylate, and 2-phenoxyethyl acrylate.
Two or more of these acrylic acid esters may be used in combination.
The amount of acrylic acid ester is preferably 50 to 100% by mass, more preferably 60 to 99% by mass, further preferably 70 to 99% by mass or less, and most preferably 80 to 99% by mass or less in 100% by mass of the monomer mixture. .. If it is less than 50% by mass, the impact resistance is lowered, the elongation at the time of tensile break is lowered, and cracks are likely to occur at the time of cutting the film.

As the other vinyl-based monomer copolymerizable with the acrylic acid ester, methacrylic acid esters are particularly preferable from the viewpoint of weather resistance and transparency. Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, and 2-methacrylic acid. Examples thereof include phenoxyethyl, 2-ethylhexyl methacrylate, phenyl methacrylate, n-octyl methacrylate and the like.

Further, aromatic vinyls and derivatives thereof, and vinyl cyanide are also preferable. Examples of these vinyl-based monomers include styrene, methylstyrene, acrylonitrile, and methacrylonitrile. In addition, unsubstituted and / or substituted maleic anhydrides, (meth) acrylamides, vinyl esters, vinylidene halides, (meth) acrylic acids and salts thereof, (hydroxyalkyl) acrylic acids and the like can be mentioned.

The multilayer structure polymer may have another polymer layer inside (center side) of the rubber portion. From the viewpoint of anti-blocking property, a monomer mixture consisting of 40 to 100% by mass of an alkyl methacrylate ester and 60 to 0% by mass of another monomer having a copolymerizable double bond thereof, and the said material. It is preferable to have a methacrylic crosslinked polymer layer obtained by polymerizing 0.01 to 10 parts by mass of a polyfunctional monomer with respect to 100 parts by mass of a monomer mixture. Examples of the monomer having a copolymerizable double bond include the above-mentioned other copolymerizable vinyl-based monomers and acrylic acid esters.
The acrylic graft copolymer comprising the rubber portion and the shell layer formed by graft polymerization on the surface of the rubber portion is 5 to 90 parts by mass (more preferably 5) of particles of the acrylic acid ester rubber-like polymer. It is preferably obtained by polymerizing 95 to 25 parts by mass of a monomer mixture containing a methacrylic acid ester as a main component in at least one step in the presence of (~ 75 parts by mass).

The methacrylic acid ester in the graft copolymer composition (monomer mixture) is preferably 50% by mass or more. If it is less than 50% by mass, the hardness and rigidity of the obtained film tend to decrease.
As the monomer used for the graft copolymerization, the above-mentioned methacrylic acid ester, acrylic acid ester, and vinyl-based monomer copolymerizable with these can be similarly used, and methacrylic acid ester and acrylic acid ester are preferably used. Will be done. Methyl methacrylate is preferable from the viewpoint of compatibility with an acrylic resin, and methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferable from the viewpoint of suppressing zipper depolymerization.

<< Polyfunctional compound >>
The rubber particles having the crosslinked structure can be obtained, for example, by polymerizing a monomer composition containing a polyfunctional compound having two or more non-conjugated double bonds per molecule.
Examples of the polyfunctional compound include divinylbenzene, allyl methacrylate, allyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyl acrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, and triallylsia. Nureto, Triallyl Isosia Nureto, Dialyl Futalate, Dialyl Malet, Divinyl Adipate, Divinyl benzene Ethylene Glycol Dimethacrylate, Divinylbenzene Ethylene Glycol Dimethacrylate, Diethylene Glycol Dimethacrylate, Diethylene Glycol Diacrylate -T, Triethylene Glycol Dimethacrylate, Triethylene Glycol Diacryllate, Trimethylol Propane Trimethacrylate, Trimethylol Propane Triacryllate, Tetramethylol Methantetramethacrylate, Tetramethylo -Lumethantetraacrylate, dipropylene glycol dimethacrylate, dipropylene glycol diacrylate and the like can be mentioned, and these may be used alone or in combination of two or more.

(Synthesis method)
As the method for producing the core-shell type rubber particles in the present invention, any suitable method capable of producing the core-shell type rubber particles can be adopted.
For example, a polymerizable monomer forming a rubber-like polymer constituting a core layer is suspended or emulsion-polymerized to produce a suspension or emulsion dispersion containing rubber-like polymer particles, and subsequently, the suspension is produced. Alternatively, a core having a multilayer structure in which the surface of the rubber-like polymer particles is coated with the glass-like polymer by adding a polymerizable monomer forming a glass-like polymer constituting the shell layer to the emulsion dispersion and radically polymerizing the mixture. A method of obtaining a shell-type elastic body can be mentioned. Here, the polymerizable monomer forming the rubber-like polymer and the polymerizable monomer forming the glassy polymer may be polymerized in one stage, or may be polymerized in two or more stages by changing the composition ratio. May be good.

In order to secure the physical balance of the acrylic resin film according to the present invention, it is desirable to appropriately control the structure of the core-shell type rubber particles.
Preferred structures of the core-shell type elastic body include, for example, (a) a soft and rubber-like core layer and a hard and glass-like shell layer, and the core layer is a (meth) acrylic crosslinked elastic weight. Those having a coalesced layer, (b) the rubber-like core layer having a multilayer structure having one or more glass-like layers inside, and having a glass-like shell layer on the outside of the core layer, and the like. Can be mentioned. By appropriately selecting the monomer type of each layer, various physical properties (mechanical characteristics, optical characteristics, particularly orientation birefringence and photoelastic coefficient) of the (meth) acrylic resin can be arbitrarily controlled. The soft and rubbery layer preferably has a glass transition temperature of the polymer of less than 20 ° C., preferably less than 0 ° C., and the hard and glassy layer preferably has a glass transition temperature of the polymer of 0 ° C. or higher. Is preferably 20 ° C. or higher.

Specific examples of the more preferable structure of the core-shell type rubber particles include, for example, (i) the shell layer of the core-shell type rubber particles preferably contains an alkyl acrylate in an amount of preferably 3% by mass or more, more preferably 10% by mass or more. More preferably, it is a non-crosslinked methacrylic resin containing 15% by mass or more, and (ii) the shell layer of the core-shell type rubber particles is composed of two or more layers having different alkyl acrylate contents, and the total is alkyl acrylate. A non-crosslinked methacrylic resin containing preferably 10% by mass or more, more preferably 15% by mass or more. (Iii) The core layer of the core-shell type rubber particles is an alkyl methacrylate, a polyfunctional monomer, or an alkyl mercaptan. In the presence of a glassy polymer layer obtained by polymerizing a mixture of other monomers as appropriate, a multilayer structure in which a rubbery polymer layer obtained by polymerizing a mixture of acrylic acrylate, polyfunctional monomer, alkyl mercaptan and other monomers as appropriate is formed. (Iv) The core layer of the core-shell type rubber particles is a peracid (persulfate,) in the presence of a glassy polymer layer polymerized using an organic peroxide as a redox type polymerization initiator. Examples thereof include those having a multilayer structure in which a rubber-like polymer layer polymerized using (perphosphate or the like) as a thermal decomposition type initiator is formed.

The total amount of the alkyl acrylate used in the shell layer is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 40% by mass or less. If it exceeds 60% by mass, the dispersibility of the core-shell type rubber particles in the matrix tends to deteriorate, the mechanical strength and transparency deteriorate, and further, it tends to cause foreign substances such as fish eyes. In addition, in terms of the productivity of the core-shell type rubber particles, the product tends to become coarse particles, which tends to cause problems. The structural design element of such a preferable core-shell type rubber particle may have only one, or a plurality of two or more design elements may be used in combination. By having such a structure, the core-shell type rubber particles can be easily dispersed well in the acrylic resin according to the present invention, and when a film is formed, there are few defects due to non-dispersion or aggregation, and the strength is increased. It is excellent in toughness, heat resistance, transparency and appearance, and whitening due to temperature change and stress is suppressed, so that a film having excellent quality can be obtained.

When the core-shell type rubber particles in the present invention are produced by emulsion polymerization, suspension polymerization, or the like, a known polymerization initiator can be used. Particularly preferable polymerization initiators include persulfates such as potassium persulfate, ammonium persulfate and ammonium persulfate, perphosphates such as sodium perphosphate, organic azo compounds such as azobisisobutyronitrile, and cumene hydroperoxides. , Hydroperoxide compounds such as tertiary butyl hydroperoxide, 1,1 dimethyl-2 hydroxyethyl hydroperoxide, peresters such as tertiary butyl isopropyl oxycarbonate, tertiary butyl peroxybutyrate, benzoyl peroxide, Examples thereof include organic peroxide compounds such as dibutyl peroxide and lauryl peroxide. These may be used as a thermal decomposition type polymerization initiator, and may be used as a redox type polymerization initiator in the presence of a catalyst such as ferrous sulfate and a water-soluble reducing agent such as ascorbic acid and sodium formaldehyde sulfoxylate. It may be appropriately selected depending on the monomer composition to be polymerized, the layer structure, the polymerization temperature conditions and the like.

When the core-shell type rubber particles in the present invention are produced by emulsion polymerization, they can be produced by ordinary emulsion polymerization using a known emulsifier. Known emulsifiers include anionics such as phosphate ester salts such as sodium alkyl sulphonate, sodium alkylbenzene sulphonate, sodium dioctyl sulphosuccinate, sodium lauryl sulfate, fatty acid sodium, and sodium polyoxyethylene lauryl ether phosphate. Surfactants and nonionic surfactants such as reaction products of alkylphenols, aliphatic alcohols and propylene oxide and ethylene oxide are shown. These surfactants may be used alone or in combination of two or more. Further, if necessary, a cationic surfactant such as an alkylamine salt may be used. Of these, from the viewpoint of improving the thermal stability of the obtained core-shell type rubber particles, a phosphate ester salt (alkali metal or alkaline earth metal) such as polyoxyethylene lauryl ether sodium phosphate is particularly used. It is preferable to polymerize. The core-shell type rubber particle latex obtained by emulsion polymerization is spray-dried, or, as is generally known, the polymer component is coagulated by adding an electrolyte or an organic solvent as a coagulant to the latex, and the polymer is appropriately heated. The polymer component is dried by performing operations such as washing and separation of the aqueous phase to obtain lumpy or powdery core-shell type rubber particles.

As the coagulant, known substances such as a water-soluble electrolyte and an organic solvent can be used, but from the viewpoint of improving the thermal stability of the obtained copolymer during molding and from the viewpoint of productivity, magnesium chloride or sulfuric acid can be used. It is preferable to use a magnesium salt such as magnesium or a calcium salt such as calcium acetate or calcium chloride.

(Refractive index)
The refractive index difference of the rubber particles from the acrylic resin (also referred to as matrix resin) constituting the film is preferably 0.015 or less, more preferably 0.012 or less, still more preferably 0.01 or less. .. When the difference in refractive index from the matrix resin is 0.015 or less, it is possible to obtain a film having excellent transparency. As a method for satisfying the above-mentioned refractive index condition, a method for adjusting the unit composition ratio of each monomer of the matrix resin and / or a composition of the polymer and / or the monomer used for each layer of the rubber particles is used. Examples include a method of adjusting the ratio.

"Measuring method"
The difference in refractive index between the matrix resin and the rubber particles can be measured as follows.
First, for the rubber particles, the rubber particles are press-molded, the average refractive index of the molded body is measured with a laser refractometer, and the value is taken as the refractive index of the rubber particles.
Similarly, for the matrix resin, the material (resin or resin composition) constituting the matrix resin is molded, the average refractive index of the molded body is measured with a laser refractometer, and the value is taken as the refractive index of the matrix resin. do.
The difference in refractive index can be obtained by calculating the difference in the refractive index values of the matrix resin and the rubber particles measured as described above.
In the present embodiment, the refractive index means the refractive index for light having a wavelength of 550 nm at 23 ° C.

《Temperature dependence》
It is preferable that the difference in refractive index between the matrix resin and the rubber particles described above is similarly low in the range of 0 to 50 ° C. For that purpose, it is preferable to make the refractive index temperature dependence of the matrix resin and the rubber particles equal.

(Birerefringence)
The acrylic resin film according to the present invention may be in a polymer oriented state due to stretching, and may be stressed during use. Even in such a case, it is preferable that the film does not exhibit birefringence, and for that purpose, it is preferable that the rubber particles also do not exhibit birefringence due to orientation or stress.
For example, the grafts described in WO2014 / 162370, having an orientation birefringence of -15 × 10 ^-4 to 15 × 10 ^-4 and a photoelastic constant of -10 × 10 ^-12 to 10 × 10 ^-12 Pa ^-1. The polymer is also preferably used as the rubber particles according to the present invention.

<< Control method >>
As for the monomer species suitable for reducing the photoelastic birefringence of the homopolymer itself of the monomers constituting the rubber particles, the monomer species having different photoelastic constants may be used in combination.

Examples of specific monomers that can be used as a reference for setting the photoelastic constant of the polymer are described below, but the present invention is not limited thereto. (The numbers in [] are the photoelastic constants of the corresponding homopolymers)
Monomer showing positive photoelastic birefringence:
Benzyl methacrylate [48.4 × 10-12Pa-1]
Dicyclopentanyl methacrylate [6.7 × 10-12Pa-1]
Styrene [10.1 × 10-12Pa-1]
Parachlorostyrene [29.0 × 10-12Pa-1
Monomer showing negative photoelastic birefringence:
Methyl methacrylate [-4.3 × 10-12Pa-1]
2,2,2-Trifluoroethyl methacrylate [-1.7 × 10-12Pa-1]
2,2,2-Trichloroethyl methacrylate [-10.2 × 10-12Pa-1]
Isobornyl methacrylate [-5.8 × 10-12Pa-1]
It is known that the photoelastic constant of the copolymer is additive to the photoelastic constant of each homopolymer corresponding to the monomer type used for the copolymerization. For example, for a binary copolymerization system of methyl methacrylate (MMA) and benzyl methacrylate (BzMA), it has been reported that photoelastic birefringence becomes almost zero at poly-MMA / BzMA = 92/8 (wt%). ing. The same applies to a mixture of two or more types of polymers (alloys), and additionability is established between the photoelastic constants of each polymer. From the above, the photoelastic constant of the homopolymer of the monomers constituting the rubber particles is lowered so that the photoelastic birefringence of the optical resin material and the optical film of the present invention is reduced, and the blending amount (wt) thereof. %) Needs to be adjusted.

Further, it is known that the orientation birefringence of the copolymer polymer is additive to the intrinsic birefringence of each homopolymer corresponding to the monomer type used for the copolymerization. The same applies to a mixture of two or more types of polymers (alloys), and additionability is established between the intrinsic birefringence of each polymer. As for the monomer species suitable for reducing the orientation birefringence of the homopolymer itself of the monomers constituting the rubber particles, a combination of monomer species having different orientation birefringence may be used.

Examples of specific monomers (inherent birefringence of homopolymers composed of the monomers) that can be used as a reference in setting the orientation birefringence of the polymer are described below, but the present invention is not limited thereto. The intrinsic birefringence is birefringence (aligned birefringence) when the polymer is completely oriented in one direction.

Polymers with positive birefringence:
Polybenzylmethacrylate [+0.002]
Polyphenylene oxide [+0.210]
Bisphenol A Polycarbonate [+0.106]
Polyvinyl chloride [+0.027]
Polyethylene terephthalate [+0.105]
Polyethylene [+0.044]
Polymers with negative intrinsic birefringence:
Polymethylmethacrylate [-0.0043]
Polystyrene [-0.100]
The data of the photoelastic constant and the orientation birefringence of some polymers are described above, but depending on the polymer, the orientation birefringence is "positive", the photoelastic constant is "negative", and both birefringences have the same sign. Not necessarily. The following Table I shows an example of the sign of the orientation birefringence and the photoelastic birefringence (constant) of some homopolymers.

For example, the composition near poly (MMA / BzMA = 82/18 (wt%)) has almost zero orientation birefringence, and the composition near poly (MMA / BzMA = 92/8 (wt%)) is photoelastic. It is known that birefringence (constant) becomes almost zero.

A good example of a polymer composition for making both photoelastic birefringence and orientation birefringence extremely small, ideally both near zero, is described in Japanese Patent No. 4624845, poly (MMA / 3FMA / BzMA = 55). .5 / 38.0 / 6.5). However, since this polymer composition is composed only of a methacrylic acid ester-based monomer, zipper depolymerization occurs in high-temperature molding, resulting in a decrease in molecular weight, which causes problems such as a decrease in mechanical strength, coloring, and foaming. .. One solution to this problem is to copolymerize a small amount of acrylic acid ester, which makes it possible to suppress excessive decomposition due to zipper depolymerization during high-temperature molding.

The composition of the homopolymer of the monomers constituting the rubber particles is not particularly limited. Among them, the monomers that can be particularly preferably used are, for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, glycidyl methacrylate, and epoxycyclohexyl methacrylate. Methyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dicyclopentanyl methacrylate, dicyclopentenyloxyethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,2-trichloroethyl Methacrylate esters such as methacrylate, isoboronyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, pentamethylpiperidinyl methacrylate, tetramethylpiperidinyl methacrylate, tetrahydrofurfuryl methacrylate; methyl acrylate, ethyl acrylate , Butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, cyclohexylmethyl acrylate, benzyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dicyclopentanyl acrylate, dicyclo acrylate Acrylic acid esters such as pentenyloxyethyl, phenylacrylate, phenoxyethyl acrylate, pentamethylpiperidinyl acrylate, tetramethylpiperidinyl acrylate, tetrahydrofurfuryl acrylate; carboxylic acids such as methacrylic acid and acrylic acid. And their esters; unsubstituted and / or substituted of maleic anhydride, citraconic acid anhydride, maleic anhydride, dichloromaleic acid anhydride, bromoanhydrous maleic acid, dibromochloride anhydride, phenylancrylic acid, diphenylanched maleic acid, etc. Maleic anhydrides; methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, isopropyl 2- (hydroxymethyl) acrylate, normal butyl 2- (hydroxymethyl) acrylate, 2- (hydroxymethyl) ) (Hydroxyalkyl) acrylic acid esters such as tertiary butyl acrylate; vinyl cyanides such as acrylonitonyl and methacrylonitrile; vinyl allenes such as styrene, α-methylstyrene, monochlorostyrene and dichlorostyrene; maleic acid and fumaric acid. And their esters, etc .; vinyl halides such as vinyl chloride, vinyl bromide, chloroprene, etc .; vinegar Vinyl oxyate; alkenes such as ethylene, propylene, butylene, butadiene, isobutylene; halogenated alkenes; allyl methacrylate, diallyl phthalate, triallyl cyanurate, monoethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate. , Polyfunctional monomers such as divinylbenzene. These vinyl-based monomers can be used alone or in combination of two or more. In particular, from the viewpoint of birefringence control, it is preferable to use a polyfunctional monomer to the extent that the polymer chain can be oriented with respect to stress, but it is particularly preferable not to use a polyfunctional monomer.

Among the above-mentioned monomers, a vinyl-based monomer having an alicyclic structure, a heterocyclic structure, or a ring structure such as an aromatic group in the molecular structure is preferable from the viewpoint of reducing the double refraction. It is more preferable to contain a vinyl-based monomer having an alicyclic structure, a heterocyclic structure or an aromatic group. For example, examples of the monomer having an alicyclic structure include dicyclopentanyl (meth) acrylate and dicyclopentenyloxyethyl (meth) acrylate. Examples of the monomer having an aromatic group include vinyl arrays such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene, or benzyl (meth) acrylate, phenyl (meth) acrylate, and (meth) acrylic. Examples thereof include phenoxyethyl acid. Examples of the monomer having a heterocyclic structure include pentamethylpiperidinyl (meth) acrylate, tetramethylpiperidinyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate. In the vinyl-based monomer having an alicyclic structure, the ring structure is preferably a polycyclic structure, and more preferably a condensed ring structure. The vinyl-based monomer having an alicyclic structure, a heterocyclic structure or an aromatic group is preferably a monomer represented by the following formula (4c).

In the above formula (4c), R ⁹ represents a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms. R ¹⁰ is a substituted or unsubstituted aromatic group having 1 to 24 carbon atoms, or a substituted or unsubstituted alicyclic group having 1 to 24 carbon atoms, and has a monocyclic structure or a heterocyclic structure. Have. The ^{substituents that R 9} and R ¹⁰ may have include, for example, a halogen, a hydroxy group, a carboxy group, an alkoxy group, a carbonyl group (ketone structure), an amino group, an amide group, an epoxy group, and a carbon-carbon group. At least one selected from the group consisting of a double bond of, an ester group (a derivative of a carboxy group), a mercapto group, a sulfonyl group, a sulfone group, and a nitro group can be mentioned. Among them, at least one selected from the group consisting of a halogen, a hydroxy group, a carboxy group, an alkoxy group, and a nitro group is preferable. l represents an integer of 1 to 4, preferably 0 or 1. m represents an integer of 0 to 1. n represents an integer of 0 to 10, preferably an integer of 0 to 2, and more preferably 0 or 1.

Among them, the vinyl-based monomer having an alicyclic structure, a heterocyclic structure or an aromatic group is preferably a (meth) acrylic monomer having an alicyclic structure, a heterocyclic structure or an aromatic group. Specifically, in the above formula (4c), R ⁹ is a (meth) acrylate-based monomer which is a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group having 1 carbon number. It is preferable that, in the above formula (4c), R ¹⁰ is a substituted or unsubstituted aromatic group having 1 to 24 carbon atoms, or a substituted or unsubstituted aromatic group having 1 to 24 carbon atoms, and is simply a simple group. It is more preferable that it is a (meth) acrylate-based monomer having a ring-type structure. Further, in the above formula (4c), l is an integer of 1 to 2 and n is an integer of 0 to 2, preferably a (meth) acrylate-based monomer.
Among the (meth) acrylate-based monomers represented by the formula (4), benzyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and phenoxyethyl (meth) acrylate are preferable.

Further, the monomer represented by the above formula (4c) is preferably contained in an amount of 1 to 99% by mass, more preferably 1 to 70% by mass, out of 100% by mass of the homopolymer of the monomer constituting the rubber particles. %, More preferably 1 to 50% by mass.

All the homopolymers of the monomers constituting the rubber particles may be mixed and polymerized in one stage. If the birefringence of the molded product made of a polymer obtained by polymerizing the homopolymer of the monomers constituting the rubber particles alone has sufficient non-birefringence to satisfy the present invention, the monomer The composition may be changed and polymerization may be carried out in two or more stages.

"Measuring method"
In order to measure the birefringence of rubber particles, as in the case of measuring the refractive index, only the rubber particles are independently molded to prepare a plate-shaped or film-shaped sample. A normal birefringence measurement may be performed using this sample.

(Particle size)
As the particle size of the core-shell type rubber particles, the particle size of the soft core layer is preferably 1 to 500 nm, more preferably 10 to 400 nm, and further preferably 50 to 300 nm. , 70-300 nm is particularly preferred.
If the particle size of the core layer of the core-shell type rubber particles is less than 1 nm, the mechanical strength of the (meth) acrylic resin is not sufficiently improved, and if it is larger than 500 nm, the (meth) acrylic resin is used. Heat resistance and transparency may be impaired.

Here, the particle size is determined by, for example, a dynamic light scattering method using MICROTRAC UPA150 (manufactured by Nikkiso Co., Ltd.) or a turbidity method for measuring the transmittance of the polymer solution per unit weight using a turbidity meter. Can be asked. In addition, a film obtained by molding a compound obtained by blending core-shell crosslinked rubber particles and polymethylmethacrylate (for example, Sumipex EX manufactured by Sumitomo Chemical Ltd.) at a weight ratio of 20:80 is used as a transmission electron microscope (manufactured by JEOL Ltd.). It is also possible to take pictures with an acceleration voltage of 80 kV, RuO4 stained ultrathin section method with JEM-1200EX), select 100 rubber particle images at random from the obtained pictures, and obtain the average value of their particle sizes. ..

(Rubber Particle Dispersion / Disperser) As a method for incorporating the rubber particles according to the present invention into an acrylic resin film, first, a rubber particle dispersion is prepared, and the dispersion is uniformly added to a dope containing an acrylic resin. , It is preferable to cast the dope into a solution to obtain an acrylic resin film containing rubber particles.

The rubber particle dispersion liquid mainly contains rubber particle powder as a raw material and an organic solvent. The organic solvent that can be used is not particularly limited as long as the rubber particles are dispersed and the dispersion liquid can be prepared.
The organic solvent used in the present invention is a solvent selected from, for example, a chlorine-based solvent such as dichloromethane and chloroform, a chain hydrocarbon having 3 to 12 carbon atoms, a cyclic hydrocarbon, an aromatic hydrocarbon, an ester, a ketone, and an ether. Is preferable. Esters, ketones and ethers may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, and decane. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane, decalin and derivatives thereof. Examples of aromatic hydrocarbons having 3 to 12 carbon atoms include benzene, toluene and xylene. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetol.

Examples of organic solvents having two or more functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. As the organic solvent used in the method for preparing the rubber particle dispersion liquid according to the present invention, one kind of organic solvent may be used alone, or two or more kinds of organic solvents may be mixed and used in an arbitrary ratio.
Examples of the organic solvent preferably used in the present invention include dichloromethane, lower alcohols, and mixtures thereof from the viewpoint of miscibility with the doping. From the viewpoint of dispersibility of the rubber particles, a hydrophilic organic solvent such as methanol or ethanol is preferably used.
For the dispersibility of rubber particles, various anionic, cationic, and nonionic surfactants and polymers for obtaining a steric repulsion effect are preferably added as dispersants as conventionally known particle dispersion stabilizing techniques. As the dispersant, the dispersant used at the time of synthesizing the rubber particles may be used as it is, a dispersant of the same type may be newly added, or a new dispersant of another type may be added.
In particular, it is preferable to use an acrylic resin as the dispersant and further disperse the fine particles in the presence of the dispersant. The acrylic resin at this time preferably has a relatively low molecular weight of 10 to 100,000. When a high molecular weight acrylic resin is used as a dispersant, cross-linking aggregation may occur to induce aggregation between rubber particles.
The content of the rubber particles in the rubber particle dispersion is preferably 1 to 50%. When the content is low, the amount of the organic solvent is large with respect to the required amount of rubber particles, and the dilution degree of the dope after addition is high, which is not preferable. A high content is not preferable because the dispersion stability of the rubber particle dispersion is low. A more preferable content is 5 to 20%.

In preparing the rubber particle dispersion liquid according to the present invention, it is preferable that the dispersion treatment is performed within 0.1 seconds to 1 minute after the raw material powder of the rubber particles and the organic solvent are mixed. Further, the dispersion treatment is preferably in-line treatment rather than batch treatment, and it is preferable that the dispersion liquid dispersed in the in-line treatment is added to the dope as it is without stagnation.
On the contrary, it is also preferable to prepare a rubber particle dispersion by batch dispersion, store it in a tank for a certain period of time, and then add it to the dope. In this case, the rubber particles are likely to aggregate during the storage period and the dispersion liquid is likely to thicken. Therefore, it is preferable to constantly stir to maintain the flow during the storage period.
When the organic solvent contains methylene chloride as a main component, the rubber particles are difficult to miscible due to its large specific gravity, and stepchildren may be generated. Therefore, in the initial miscibility state, it is preferable to mix a large amount of rubber particle powder and a large amount of organic solvent with each other in a small amount. That is, it is preferable that the rubber particle powder and the organic solvent are weighed online and then provided, the first mixing is performed in a small space of about 0.1 to 10 L, and the in-line mixing is sequentially sent to the disperser. Examples of the in-line mixing device include a flow jet mixer continuous injection mixer manufactured by Koken Pautex Co., Ltd., and an in-line type circulating solid-liquid mixing / dispersing device CMX manufactured by IKA.

As the disperser for dispersing the rubber particles, a normal disperser can be used. Dispersers can be broadly divided into media dispersers and medialess dispersers. Examples of the media disperser include ball mills, sand mills, and dyno mills. Examples of the medialess disperser include an ultrasonic type, a centrifugal type, and a high pressure type, but in the present invention, a high pressure disperser is preferable.

The high-pressure disperser is a device that creates special conditions such as high shear and high-pressure conditions by passing a composition in which fine particles and a solvent are mixed through a thin tube at high speed. By processing with a high-pressure disperser, for example, ^{it is preferable that the maximum pressure condition inside the device is 9.8 × 10 2} N or more in a thin tube having a tube diameter of 1 to 2000 μm. More preferably, it is 1.96 × 10 ³ N or more. At that time, those having a maximum reaching speed of 100 m / sec or more and those having a heat transfer speed of 100 kcal / hr or more are preferable.
Examples of the high-pressure disperser as described above include an ultra-high pressure homogenizer (2 trade names: microfluidizer) manufactured by Microfluidics Corporation, a nanomizer manufactured by Nanomizer, or Ultratarax, and other manton-golin type high-pressure dispersers such as Izumi. Examples thereof include a homogenizer manufactured by Food Machinery, manufactured by Sanwa Machinery Co., Ltd., and a product number UHN-01.
It is also preferable to connect a plurality of these dispersers in series or in parallel in order to perform in-line processing. For example, before introducing the admixture treated by the flow jet mixer into the Menton-Gorlin type high-pressure disperser, some dispersion treatment should be performed in advance with an emulsification disperser (for example, Milder manufactured by Matsubo Co., Ltd.). Is also preferred.
The obtained dispersion may contain coarse agglomerated particles, which are preferably removed with a strainer or a filter. The preferable filtration accuracy at this time is 5 μm to 500 μm.

(Structure in film)
The state of the rubber particles in the acrylic resin film according to the present invention is most preferably a state in which the primary particles are uniformly and monodispersed. On the contrary, there may be loose aggregation or uneven distribution within a range not contrary to the gist of the present invention.
For example, a form in which the abundance concentration of the rubber particles is large near the film surface layer, or conversely a form in which the abundance concentration of the rubber particles is large near the film center layer can be selected according to the purpose.
The particle shape of each rubber particle can be arbitrarily selected from a spherical shape, a flat shape, a rod shape, and the like. Since the surface unevenness of the film is less affected, a flat shape is preferable, and a flat surface is preferably present in parallel with the film surface.

(3) Cellulose Achillate In the acrylic resin film according to the present invention, by adding a small amount of a cellulose acylate resin to the dope, the solubility of foreign matter caused by the additive is increased, and the effect of reducing foreign matter failure becomes remarkable. It is presumed that the foreign matter caused by the additive that does not dissolve in the acrylic resin is compatible with the highly polar cellulose acylate resin, so that the foreign matter is significantly reduced.

Further, from the viewpoint of improving the coatability when the functional layer is applied to the surface of the film and reducing repelling and coating unevenness, it is preferable to use a small amount of cellulose acylate in combination. Further, by incorporating the cellulose acylate resin, the adhesion to the hard coat base material is increased, and the hardness of the hard coat film can be increased.

Particularly suitable cellulose acylates include those having an acyl group substitution degree in the range of 2.50 to 2.98, and the acyl group is at least one selected from an acetyl group, a propionyl group and a butyryl group. .. Specific examples thereof include cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose propionate, cellulose butyrate, cellulose acetate propionate butyrate, and in the present invention, cellulose triacetate and cellulose. Acetate propionate and cellulose acetate butyrate are preferred. The degree of substitution of the acetyl group is preferably 1.40 or more. The cellulose used as a raw material for cellulose acylate is not particularly limited, and cotton linter, wood pulp, kenaf and the like can be used. These may be mixed and used. The ratio of the cellulose acylate synthesized from the cotton linter is preferably 60% by mass or more, more preferably 85% by mass or more, and most preferably 100% by mass. The method for synthesizing cellulose acylate is not particularly limited, but for example, it can be synthesized by the method described in JP-A-10-45804. The method for measuring the degree of substitution of the acyl group can be measured by ASTM-D817-96. The number average molecular weight of the cellulose acylate is preferably in the range of 70,000 to 300,000, more preferably in the range of 80,000 to 200,000 in order to obtain preferable mechanical strength as a protective film for a polarizing plate.

(4) Organic Thickener In the method for producing an acrylic resin film of the present invention, the following organic thickener described in JP-A-2005-314636 is used from the viewpoint of improving ductility and improving the occurrence of horizontal steps and unevenness. , Preferably added.

The casting method using an organic solvent as in the present invention is very advantageous from the viewpoint of productivity, but it is not easy to keep the solvent drying constant immediately after casting, and surface unevenness is likely to occur. The planar unevenness referred to here is a streak caused by poor leveling after casting, a drying unevenness caused by a difference in solvent drying rate, and a wind unevenness which is a thickness unevenness caused by a drying wind.

As one means for preventing unevenness while forming a uniform film, a method of increasing the viscosity of the coating liquid to prevent flow can be considered. It is known to add a thickener such as a polymer to increase the viscosity of the dope, but simply increasing the viscosity of the dope deteriorates the leveling property and causes streaks during casting. Connect. As a means for preventing the generation of unevenness during drying and the generation of streaks during casting, a method of imparting thixotropy to the dope by adding an additive having thixotropy (hereinafter referred to as thixotropy) is preferable.

for that reason,
[1] It is preferable to use an organic solvent-based thickener composed of a compound represented by the following general formula (1b), which satisfies the following condition (a).
General formula (1b)
(R) t-Z- (B) s
In the formula, R represents an alkyl group substituted with at least 8 fluorine atoms having 4 or more carbon atoms, Z represents a (t + s) -valent linking group, and B represents a substituted or unsubstituted alkyl group or aryl group. , Or a heterocyclic group. t is an integer from 1 to 6, and s is an integer from 1 to 6.

In the formula, R represents an alkyl group substituted with at least 8 fluorine atoms having 4 or more carbon atoms, and R may be substituted with at least 8 fluorine atoms, and may be linear, branched and cyclic. It may have any structure. Further, it may be further substituted with a substituent other than the fluorine atom, or may be substituted only with the fluorine atom. Examples of the substituent other than the fluorine atom of R include an alkenyl group, an aryl group, an alkoxyl group, a halogen atom other than fluorine, a hydroxy group, an aryloxycarbonyl group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group and the like. ..

Z represents a linking group having a (t + s) value, and is not particularly limited as long as it connects R and B. t is an integer from 1 to 6 and s is an integer from 1 to 6, preferably t is an integer from 2 to 4, and more preferably t is 2 or 3, most preferably. Preferably t is 2. Further, s is preferably an integer from 1 to 4, and more preferably s is an integer from 1 to 3.

As Z, an amino acid derivative is preferably used. The asymmetric carbon of the amino acid in the amino acid derivative may be optically active or racemic. Optically active substances are preferably used.

B represents a substituted or unsubstituted alkyl group, an aryl group, or a heterocyclic group.

<< Condition (a) >>
A liquid containing the compound represented by the general formula (1b) at a concentration of 5% by mass or less with respect to the viscosity η0 of the solvent at any shear rate in the range of 0.01 to 5000s ^-1. It has a region where the relative viscosity η1 / η0 of the viscosity η1 is 2 or more. The solvent that can be used here is not particularly limited as long as the desired effect can be obtained, but is preferably toluene, hexane, isopropanol, ethanol, methanol, chloroform, methyl ethyl ketone, 2-methylpentanone, and cyclohexanone. Toluene, methyl ethyl ketone, 2-methylpentanone and cyclohexanone are more preferable, and methyl ethyl ketone, 2-methylpentanone and cyclohexanone are most preferable.

[2] It is preferable that the organic solvent-based thixotropy-imparting agent is composed of the compound represented by the general formula (1b), which satisfies the following condition (b).

<< Condition (b) >>
In a solution containing the compound represented by the general formula (1b) in a solvent at a concentration of 5% by mass or less, the viscosity η ( _x1 ) at any shear rate _x1 ^{in the range of 0.01 to 5000s -1.} , _X2 / _x1 ≧ 10 The value η ( _x1 ) / η ( _x2 ) with respect to the viscosity η ( _x2 ) at the shear rate _x2 is 1.5 or more.

[3] The organic solvent-based thickener or thixotropy-imparting agent according to the item [1] or [2], wherein the compound represented by the general formula (1b) is represented by the following general formula (2b). Is preferable.

In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group, but _{at least one of R 1} and R ₂ represents an alkyl group substituted with at least 8 or more fluorine atoms. R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom or substituent, T ₁ , T ₂ and L ₁ each independently represent a divalent linking group or single bond, where k is 0 or 1. .. B represents a substituted or unsubstituted alkyl group, an aryl group, or a heterocyclic group.

[4] The organic solvent-based thickening according to any one of [1] to [3], wherein the compound represented by the general formula (1b) is represented by the following general formula (3b). It is preferably an agent or a thixotropy-imparting agent.

In the formula, R ₁ and R ₂ each independently represent an alkyl group substituted with at least 8 fluorine atoms having 4 or more carbon atoms. B represents a substituted or unsubstituted alkyl group, an aryl group, or a heterocyclic group. T ₃ and _{T 4} are each independently -O -, - S- or _{-NR 23} - represents a. R ₂₃ represents a hydrogen atom or a substituent, L ₁ represents a divalent linking group or a single bond, and k is 0 or 1.

[5] The organic solvent-based thickening according to any one of [1] to [4], wherein the compound represented by the general formula (1b) is represented by the following general formula (4b). It is preferably an agent or a thixotropy-imparting agent.

In the formula, A ₁ and A ₂ independently represent a fluorine atom or a hydrogen atom, respectively. n ₁₁ and n ₂₁ each independently represent an integer of 0 to 6, and n ₁₂ and n ₂₂ each independently represent an integer of 3 to 12. T ₃ and _{T 4} are each independently -O -, - S- or _{-NR 23} - represents a. R ₂₃ represents a hydrogen atom or a substituent, and L ₁ represents a divalent linking group or a single bond. B represents a substituted or unsubstituted alkyl group, an aryl group, or a heterocyclic group, and k is 0 or 1.

Specific examples of the compounds represented by the general formulas (1b) to (4b) are preferably selected from the compounds described in paragraphs [0083] to [089] of JP-A-2005-314636, and are in the dope. The content of the fluorine-containing compound is not particularly limited, but is usually 0.01 to 10% by mass (% by mass with respect to the total mass of the dope), preferably 0.01 to 5% by mass, and more preferably 0 during the dope. It can be contained in an amount of 0.01 to 2.5% by mass. Further, the fluorine-containing compound may be contained in only one type or in a plurality of types.

(5) Matting agent (matting agent)
The matting agent, which is one of the fine particles used in the film of the present invention, is usually used as an additive of the film, and in order to improve the poor slipperiness of the film surface, unevenness is imparted to the film surface. It is effective to add fine particles of organic and inorganic substances to increase the roughness of the film surface and to make it so-called matte, thereby reducing the adhesiveness.

However, the rougher the surface, the higher the haze, and the lower the transparency, so the average particle size and content are limited. The fine particles of the matting agent used in the present invention have an average particle size in the range of 1 to 1000 nm, preferably 1 to 100 nm, and more preferably 3 to 50 nm.

Further, when the fine particles of the matting agent are added to various films and used, the content in the film is in the range of 0.03 to 1% by mass, regardless of whether it is spherical or amorphous fine particles, with respect to 100% by mass of the film. Yes, preferably in the range of 0.03 to 0.60% by mass, and more preferably in the range of 0.03 to 0.5% by mass.

The range of preferable haze of the acrylic resin film containing the matting agent in the present invention is 2.0% or less, more preferably 1.2% or less, and particularly preferably 0.5% or less. The acrylic resin film to which the matting agent is added has a preferable coefficient of static friction of 1.5 or less, and particularly preferably 1.0 or less. When the static friction coefficient is 1.5 or less, the acrylic resin film does not cause creases or wrinkles during winding in film formation and processing. The uniform tension is not applied to the acrylic resin film, and there is no problem that unintended non-uniform optical characteristics are exhibited on the film surface.

The coefficient of static friction is measured between the same materials, and specifically, it is measured according to the method described in Examples.

The matting agent used is not particularly limited as long as it is usually used for a film, and two or more kinds of these matting agents may be mixed and used. Examples of the matting agent include inorganic compounds and polymer compounds. Examples of the inorganic compound include fine powders of inorganic substances such as barium sulfate, manganese colloid, titanium dioxide, strontium barium sulfate, and silicon dioxide, and further, for example, synthetic silica obtained by a wet method or gelation of silicic acid. Examples thereof include silicon dioxide and titanium dioxide (rutyl type and anatas type) produced by slug and sulfuric acid. It can also be obtained by pulverizing an inorganic substance having a relatively large particle size, for example, 20 μm or more, and then classifying it (vibration filtration, wind power classification, etc.). The inorganic fine particles containing silicon are preferable in that the turbidity is lowered and the haze of the film can be lowered. Most of the fine particles such as silicon dioxide are surface-treated with an organic substance, but such fine particles are preferable because they can reduce the surface haze of the film. Preferred organic substances for surface treatment include halosilanes, alkoxysilanes, silazanes, siloxanes and the like.

Further, examples of the polymer compound include polytetrafluoroethylene, cellulose acetate, polystyrene, polymethylmethacrylate, polypropylmethacrylate, polymethylacrylate, polyethylene carbonate, starch and the like, and crushed grade products thereof are also mentioned. Alternatively, a polymer compound synthesized by a suspension polymerization method, a polymer compound formed into a spherical shape by a spray dry method, a dispersion method, or the like, or an inorganic compound can be used.

Further, a polymer compound which is a polymer of one kind or two or more kinds of monomer compounds as described below may be made into particles by various means. Specific examples of the monomer compound of the polymer compound include acrylic acid ester, methacrylic acid ester, itaconic acid diester, crotonic acid ester, maleic acid diester, and phthalic acid diesters, and examples of the ester residue include methyl. Ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, 2-chloroethyl, cyanoethyl, 2-acetoxyethyl, dimethylaminoethyl, benzyl, cyclohexyl, furfuryl, phenyl, 2-hydroxyethyl, 2-ethoxyethyl, glycidyl, ω -Ester polyethylene glycol (additional number of moles 9) and the like can be mentioned.

Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate, vinyl methoxy acetate, vinyl phenyl acetate, vinyl benzoate, vinyl salicylate and the like. Can be mentioned. Examples of olefins include dicyclopentadiene, ethylene, propylene, 1-butene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, 2,3-dimethylbutadiene and the like.

Examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, chlormethyl styrene, methoxy styrene, acetoxy styrene, chlor styrene, dichloro styrene, brom styrene, trifluoromethyl styrene and vinyl. Examples include benzoic acid methyl ester.

Acrylamides include acrylamide, methyl acrylamide, ethyl acrylamide, propyl acrylamide, butyl acrylamide, tert-butyl acrylamide, phenyl acrylamide, dimethyl acrylamide and the like; Amid, tert-butylmethacrylamide, etc .; allyl compounds such as allyl acetate, allyl caproate, allyl laurate, allyl benzoate, etc .; vinyl ethers, such as methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether, dimethyl. Aminoethyl vinyl ether and the like; vinyl ketones such as methylvinyl ketone, phenylvinyl ketone, methoxyethyl vinylketone and the like; vinyl anocyclic compounds such as vinylpyridine, N-vinylimidazole, N-vinyloxazolidone, N-vinyltriazole, etc. N-vinylpyrrolidone and the like; unsaturated nitriles such as acrylonitrile and methacrylonitrile; polyfunctional monomers such as divinylbenzene, methylenebisacrylamide, ethylene glycol dimethacrylate and the like.

In addition, acrylic acid, methacrylic acid, itaconic acid, maleic acid, monoalkyl itaconate (eg, monoethyl itaconate, etc.); monoalkyl maleate (eg, monomethyl maleate, etc .; styrene sulfonic acid, vinylbenzyl sulfonic acid, vinyl). Sulfonic acid, acryloyloxyalkyl sulfonic acid (eg, acryloyloxymethyl sulfonic acid); methacryloyloxyalkyl sulfonic acid (eg, methacryloyloxyethyl sulfonic acid, etc.); acrylamide alkyl sulfonic acid (eg, 2-acrylamide-2-methylethane). (Sulphonic acid, etc.); Methacrylate-alkylsulfonic acid (eg, 2-methacrylamide-2-methylethanesulfonic acid, etc.); Acryloyloxyalkyl phosphate (eg, acryloyloxyethyl phosphate, etc.); These acids are alkaline. It may be a salt of a metal (for example, Na, K, etc.) or an ammonium ion, and other monomer compounds include US Pat. No. 3,459,790, No. 3348708, No. 3554987, No. 4215195, and the same. It is preferable to use the crosslinkable monomer described in Japanese Patent Application Laid-Open No. 4247673 and JP-A-57-205735. Specific examples of such a crosslinkable monomer include N- (2- (2-). Examples thereof include acetoacetoxyethyl) acrylamide and N- (2- (2-acetoacetoxyethoxy) ethyl) acrylamide.

These monomer compounds may be used as particles of a polymer polymerized alone, or may be used as particles of a copolymer polymerized by combining a plurality of monomers. Among these monomer compounds, acrylic acid esters, methacrylic acid esters, vinyl esters, styrenes, and olefins are preferably used. Further, in the present invention, particles having a fluorine atom or a silicone atom as described in JP-A No. 62-14647, JP-A-62-17744, and JP-A-62-17743 may be used.
The matting fine particles of these polymers and copolymers preferably have a glass transition temperature higher than 25 ° C.

Among these, polystyrene, polymethyl (meth) acrylate, polyethyl acrylate, poly (methyl methacrylate / methacrylic acid = 95/5 (molar ratio)), poly (styrene / styrene sulfonic acid = 95/5) are preferably used as the particle composition. (Mole ratio), polyacrylonitrile, poly (methyl methacrylate / ethyl acrylate / methacrylic acid = 50/40/10), silica and the like can be mentioned.

Further, as the matting agent used in the present invention, particles having a reactive (particularly gelatin) group described in JP-A-64-77052 and European Patent No. 307855 can also be used. Furthermore, a large amount of groups that are alkaline or acidic and can be dissolved can be contained. The matting agent contains an inorganic compound or a polymer compound, and the average primary particle size thereof is preferably in the range of ^{10-3 to 10 μm.} The average primary particle size is ^{more preferably in the range of 10-3} to 10 μm, further preferably in the range of 0.005 to 5 μm, and particularly preferably in the range of 0.01 to 3 μm. Further, the matting agent is preferably silicon dioxide fine particles.

(Organic solvent used for fine particle dispersion of matting agent)
The organic solvent used in the preparation of the fine particle dispersion liquid of the matting agent is not particularly limited as long as the fine particles of the matting agent are dispersed and the dispersion liquid can be prepared. The organic solvent used in the present invention is a solvent selected from, for example, a chlorine-based solvent such as dichloromethane and chloroform, a chain hydrocarbon having 3 to 12 carbon atoms, a cyclic hydrocarbon, an aromatic hydrocarbon, an ester, a ketone, and an ether. Is preferable. Esters, ketones and ethers may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, and decane. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane, decalin and derivatives thereof. Examples of aromatic hydrocarbons having 3 to 12 carbon atoms include benzene, toluene and xylene. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetol. Examples of organic solvents having two or more functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. As the organic solvent used in the method for preparing the matting fine particle dispersion liquid according to the present invention, one kind of organic solvent may be used alone, or two or more kinds of organic solvents may be mixed and used in an arbitrary ratio. ..

When the fine particles of the matting agent are dispersed, if the amount of the organic solvent is small, sufficient dispersion cannot be performed, aggregates are generated, and a foreign matter failure is caused. On the contrary, when the amount of the organic solvent is large, the dispersibility of the fine particles of the matting agent is excellent, but a large amount of the dispersion liquid is prepared, which is not preferable in terms of handling in production. Therefore, the amount of the organic solvent used is preferably in the range of 1000 to 100,000 parts by mass, more preferably in the range of 1500 to 40,000 parts by mass, and more preferably 2000 to 20000 with respect to 100 parts by mass of the fine particles of the matting agent. It is particularly preferable to set it in the range of parts by mass.

(Dispersant)
Next, the dispersant used in the present invention will be described. When the fine particle dispersion of the matting agent and the dope are mixed in-line, if a dispersion having a low viscosity is used, it is difficult to add the dope with a high viscosity due to the difference in viscosity, and the mixing does not go well. This problem is solved by dissolving the dispersant in the dispersion and slightly increasing the viscosity. Therefore, a resin is usually used as the dispersant. Considering only the mixing, it is preferable that the dope and the dispersion have the same viscosity, but considering the dispersibility of the matting agent as the fine particle dispersion and the ease of handling, the viscosity of the fine particle dispersion of the matting agent is 0.7 mPa. -It is preferably s or more, and more preferably 1 mPa · s or more. Further, if the weight average molecular weight of the dispersant is made too large in order to increase the viscosity, the dispersant causes poor solubility and deterioration of filterability. Therefore, in order to prepare a dispersion liquid having excellent solubility and filterability that is not defeated by the dope, the weight average molecular weight of the dispersant is preferably in the range of 1000 to 500000, more preferably in the range of 1000 to 30000, and is from 30,000 to 30,000. The range of 200,000 is more preferred.

It is preferable to use an acrylic resin as the dispersant and further disperse the fine particles in the presence of the dispersant. This is preferable from the viewpoint that the compatibility between the fine particle dispersion liquid and the dope is improved when the dope is prepared, the stability of the dispersed fine particles is improved when the dope is cast, and the dope without aggregates can be formed. ..

(6) Nitrogen-Containing Heterocyclic Compound The acrylic resin film according to the present invention preferably contains the following nitrogen-containing heterocyclic compound in order to control optical performance such as retardation. The nitrogen-containing heterocyclic compound is a nitrogen-containing heterocyclic compound having a molecular weight in the range of 100 to 800, and is preferably a compound having a structure represented by the following general formula (A1). By using a compound having a structure represented by the following general formula (A1) together with an acrylic resin, for example, when a polarizing plate is used in a liquid crystal display device, the occurrence of phase difference fluctuation due to environmental humidity fluctuation is suppressed and contrast is suppressed. It is possible to suppress the decrease and the occurrence of color unevenness. Furthermore, it can also function as a phase difference increasing agent.

The molecular weight in the range of 250 to 450 is a preferable range from the viewpoint of the effect of suppressing the fluctuation of the phase difference due to the humidity fluctuation and the generation of scattered matter.

(Compound having a structure represented by the general formula (A1))

In the above general formula (A1), A ₁ , A ₂ and B are each independently an alkyl group (methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, 2- (Etihexyl group, etc.), cycloalkyl group (cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), aromatic hydrocarbon ring or aromatic heterocycle. Among these, an aromatic hydrocarbon ring or an aromatic heterocycle is preferable, and a 5- or 6-membered aromatic hydrocarbon ring or an aromatic heterocycle is particularly preferable.

The structure of the 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocycle is not limited, but for example, a benzene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, 1,2,3-triazole ring, 1,2. , 4-Triazole ring, Tetrazole ring, Fran ring, Oxazole ring, Isoxazole ring, Oxazole ring, Isoxazolezole ring, Thiophen ring, Thiazole ring, Isothiazole ring, Thiasiazole ring, Isothiazole ring and the like. ..

The _{5- or 6-membered aromatic hydrocarbon ring or aromatic heterocycle represented by A 1} , A ₂ and B may have a substituent, and the substituent may be, for example, a halogen atom ( Fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), alkyl group (methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, 2-ethylhexyl group, etc.), cycloalkyl Group (cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), alkenyl group (vinyl group, allyl group, etc.), cycloalkenyl group (2-cyclopenten-1-yl, 2-cyclohexene-1-yl group, etc.) ), Alkinyl group (ethynyl group, propargyl group, etc.), aromatic hydrocarbon ring group (phenyl group, p-tolyl group, naphthyl group, etc.), aromatic heterocyclic group (2-pyrrole group, 2-furyl group, 2) -Thienyl group, pyrrol group, imidazolyl group, oxazolyl group, thiazolyl group, benzoimidazolyl group, benzoxazolyl group, 2-benzothiazolyl group, pyrazolinone group, pyridyl group, pyridinone group, 2-pyrimidinyl group, triazine group, pyrazole group, 1,2,3-triazole group, 1,2,4-triazole group, oxazole group, isooxazole group, 1,2,4-oxadiazol group, 1,3,4-oxadiazole group, thiazole group, Isothiazole group, 1,2,4-thiodiazol group, 1,3,4-thiadiazol group, etc.), cyano group, hydroxy group, nitro group, carboxy group, alkoxy group (methoxy group, ethoxy group, isopropoxy group, tert) -Butoxy group, n-octyloxy group, 2-methoxyethoxy group, etc.), aryloxy group (phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoyl) Aminophenoxy group, etc.), acyloxy group (formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group, etc.), amino group (amino group, methylamino group, dimethylamino) Group, anilino group, N-methyl-anilino group, diphenylamino group, etc.), acylamino group (formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, etc.), alkyl and arylsulfonylamino group (methyl) Sulfonylamino group, butylsulfonylamino group, fe Nylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group, etc.), mercapto group, alkylthio group (methylthio group, ethylthio group, n-hexadecylthio group, etc.), arylthio group (phenylthio) Group, p-chlorophenylthio group, m-methoxyphenylthio group, etc.), sulfamoyl group (N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N'-phenylcarbamoyl) sulfamoyl group, etc.), sulfo group, acyl group (acetyl group, pivaloylbenzoyl group, etc.), carbamoyl group ( Examples thereof include a carbamoyl group, an N-methylcarbamoyl group, an N, N-dimethylcarbamoyl group, an N, N-di-n-octylcarbamoyl group, an N- (methylsulfonyl) carbamoyl group, etc.).

In the general formula (A1), A ₁ , A ₂ and B may represent a benzene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a 1,2,3-triazole ring or a 1,2,4-triazole ring. , It is preferable because an acrylic resin film having an excellent effect of varying optical properties and excellent durability can be obtained.

In the general formula (A1), T ₁ and T ₂ preferably independently represent a pyrrole ring, a pyrazole ring, an imidazole ring, a 1,2,3-triazole ring or a 1,2,4-triazole ring, respectively. .. Among these, a pyrazole ring, a triazole ring, or an imidazole ring is preferable because a resin composition having a particularly excellent effect of suppressing the fluctuation of the phase difference with respect to humidity fluctuation and having excellent durability can be obtained. It is particularly preferable to have. The pyrazole ring, 1,2,3-triazole ring, 1,2,4-triazole ring, and imidazole ring represented by _{T 1} and T _{2 may be tautomers.} The specific structures of the pyrrole ring, pyrazole ring, imidazole ring, 1,2,3-triazole ring or 1,2,4-triazole ring are shown below.

In the formula, * represents the bonding position with _{L 1} , L ₂ , L ₃ or L ₄ in the general formula (A1). R ⁵ represents a hydrogen atom or a non-aromatic substituents. Examples of the non-aromatic substituent represented by R ⁵ include a group similar to the non-aromatic substituent among the substituents that _{A 1 may have in the general formula (A1).} When the ^{substituent represented by R 5} is a substituent having an aromatic group, A ₁ and T ₁ or B and T ₁ are easily twisted, and A ₁ , B and T ₁ form an interaction with an acrylic resin. It is difficult to suppress fluctuations in optical characteristics because it is not possible. To increase the variation suppression effect of the optical properties is preferably R ⁵ is a hydrogen atom, an alkyl group or an acyl group having 1 to 5 carbon atoms of 1 to 5 carbon atoms, and particularly preferably a hydrogen atom ..

In the general formula (A1), T ₁ and T ₂ may have a substituent, and the substituent may be a substituent that _{A 1} and A ₂ in the general formula (A 1) may have. Similar groups can be mentioned.

In the general formula (A1), L ₁ , L ₂ , L ₃ and L ₄ each independently represent a single bond or a divalent linking group, and are 5-membered or 6 via two or less atoms. A member aromatic hydrocarbon ring or aromatic heterocycle is linked. Through two or less atoms means the minimum number of atoms existing between the substituents to be linked among the atoms constituting the linking group. The divalent linking group having 2 or less linked atoms is not particularly limited, but is composed of an alkylene group, an alkenylene group, an alkynylene group, O, (C = O), NR, S, and (O = S = O). It represents a divalent linking group selected from the group consisting of, or a linking group in which two of them are combined. R represents a hydrogen atom or a substituent. Examples of the substituent represented by R include an alkyl group (methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, 2-ethylhexyl group, etc.) and a cycloalkyl group (. Cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), aromatic hydrocarbon ring group (phenyl group, p-tolyl group, naphthyl group, etc.), aromatic heterocyclic group (2-furyl group, 2-thienyl group, etc.) Group, 2-pyrimidinyl group, 2-benzothiazolyl group, 2-pyridyl group, etc.), cyano group and the like are included. The _{divalent linking group represented by L 1} , L ₂ , L ₃ and L ₄ may have a substituent, and the substituent is not particularly limited. For example, A in the above general formula (A1). _{The same} groups as the substituents that 1 and A ₂ may have can be mentioned.

In the general formula (A1), L ₁ , L ₂ , L ₃ and L ₄ are resin that adsorbs water by increasing the flatness of the compound having the structure represented by the general formula (A1). Single bond or O, (C = O) -O, O- (C = O), (C = O) -NR or NR- (C = O) is preferable, and a single bond is more preferable.

In the general formula (A1), n represents an integer of 0 to 5. When n represents an integer of 2 or more, the plurality of A ₂ , T ₂ , L ₃ , and L ₄ in the general formula (A1) may be the same or different. The larger n is, the stronger the interaction between the compound having the structure represented by the general formula (A1) and the resin that adsorbs water, so that the effect of suppressing fluctuations in optical properties is excellent, and the smaller n is, the more water is. Excellent compatibility with the resin that adsorbs. Therefore, n is preferably an integer of 1 to 3, and more preferably an integer of 1 to 2.

<Compound having a structure represented by the general formula (A2)>
The compound having the structure represented by the general formula (A1) is preferably a compound having the structure represented by the general formula (A2).

(In the formula, A ₁ , A ₂ , T ₁ , T ₂ , L ₁ , L ₂ , L ₃ and L _{4 are A 1} , A ₂ , T ₁ , T ₂ , L in the general formula (A 1), respectively. _1. Synonymous with L ₂ , L ₃ and L _{4. A 3} and T ₃ represent the same groups as _{A 1} and T ₁ in the general formula (A _{1), respectively. L 5} and L ₆ represent the general. _{It represents the same group as L 1} in the formula (A1). M represents an integer from 0 to 4.)
Since the smaller m is, the better the compatibility with the cellulose acylate, m is preferably an integer of 0 to 2, and more preferably an integer of 0 to 1.

<Compound having a structure represented by the general formula (A1.1)>
The compound having the structure represented by the general formula (A1) is preferably a triazole compound having the structure represented by the following general formula (A1.1).

_(Wherein, A 1, B, _{L 1} and _{L 2,} .k representing the _A 1, B, the same group as _{L 1} and _{L 2} in formula (A1) represents an integer of 1 to 4 . T ₁ represents a 1,2,4-triazole ring.)
Further, the triazole compound having the structure represented by the general formula (A1.1) is preferably a triazole compound having the structure represented by the following general formula (A1.2).

(In the formula, Z represents the structure of the following general formula (A1.2a). Q represents an integer of 2 to 3. At least two Zs are for at least one Z substituted with a benzene ring. It binds to the ortho-position or the meta-position.)

(In the formula, R ¹⁰ represents a hydrogen atom, an alkyl group or an alkoxy group. P represents an integer of 1 to 5. * represents a bond position with a benzene ring. T ₁ represents a 1,2,4-triazole ring. Represents.)
The compound having the structure represented by the general formula (A1), (A2), (A1.1) or (A1.2) may form a hydrate, a solvate or a salt. In the present invention, the hydrate may contain an organic solvent, and the solvate may contain water. That is, the "hydrate" and "solvate" include a mixed solvate containing both water and an organic solvent. The salt includes an acid addition salt formed of an inorganic or organic acid. Examples of inorganic acids include, but are not limited to, hydrohalic acids (hydrochloric acid, hydrobromic acid, etc.), sulfuric acid, phosphoric acid, and the like. Examples of organic acids include acetic acid, trifluoroacetic acid, propionic acid, butyric acid, oxalic acid, citric acid, benzoic acid, alkyl sulfonic acid (methane sulfonic acid, etc.), and allyl sulfonic acid (benzene sulfonic acid, 4-toluene). Sulfonic acid, 1,5-naphthalenedi sulfonic acid, etc.), and the like, and are not limited thereto. Of these, hydrochloride, acetate, propionate and butyrate are preferred.

As an example of a salt, the acidic moiety present in the parent compound is a metal ion (eg, alkali metal salt, such as sodium or potassium salt, alkaline earth metal salt, such as calcium or magnesium salt, ammonium salt, alkali metal ion, alkaline earth). Examples thereof include salts formed when substituted with (such as metal ions or aluminum ions) or adjusted with organic bases (such as ethanolamine, diethanolamine, triethanolamine, morpholine, piperidine, etc.) and also these. Not limited. Of these, sodium salt and potassium salt are preferable.

Examples of solvents included in solvates include any of the common organic solvents. Specifically, alcohols (eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol), esters (eg, ethyl acetate), hydrocarbons (eg, toluene, hexane). , Heptane), ether (eg, tetrahydrofuran), nitrile (eg, acetonitrile), ketone (acetone) and the like. It is preferably a solvate of an alcohol (eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol). These solvents may be the reaction solvent used in the synthesis of the compound, the solvent used in the crystallization purification after the synthesis, or a mixture thereof.

Further, two or more kinds of solvents may be contained at the same time, or water and a solvent may be contained (for example, water and alcohol (for example, methanol, ethanol, t-butanol, etc.)).

Even if the compound having the structure represented by the general formula (A1), (A2), (A1.1) or (A1.2) is added in a form not containing water, a solvent or a salt, the present invention can be used. A hydrate, solvate or salt may be formed in the resin composition or acrylic resin film of the present invention.

The molecular weight of the compound having the structure represented by the general formula (A1), (A2), (A1.1) or (A1.2) is not particularly limited, but the smaller the molecular weight, the better the compatibility with the resin and the larger the molecular weight. The more the effect of suppressing fluctuations in the optical value with respect to changes in environmental humidity is, the more preferably 150 to 2000, more preferably 200 to 1500, and even more preferably 300 to 1000.

Further, the nitrogen-containing heterocyclic compound according to the present invention is more preferably a compound having a structure represented by the following general formula (A3).

(A in the formula represents a pyrazole ring, Ar ₁ and Ar ₂ represent an aromatic hydrocarbon ring or an aromatic heterocycle, respectively, _{and may have a substituent. R 1} is a hydrogen atom, an alkyl group, or an acyl group. , A sulfonyl group, an alkyloxycarbonyl group, or an aryloxycarbonyl group, q represents an integer of 1 to 2, and n and m represent an integer of 1 to 3).
The _{aromatic hydrocarbon ring or aromatic heterocycle represented by Ar 1} and Ar ₂ may be the 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocycle listed in the general formula (A1), respectively. preferable. Examples of the substituents of Ar ₁ and Ar ₂ include the same substituents shown in the compound having the structure represented by the general formula (A1).

Specific examples of R ₁ include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.) and an alkyl group (methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl). Group, 2-ethylhexyl group, etc.), acyl group (acetyl group, pivaloylbenzoyl group, etc.), sulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, etc.), alkyloxycarbonyl group (eg, methoxycarbonyl group), Examples thereof include an aryloxycarbonyl group (for example, a phenoxycarbonyl group, etc.).

q represents an integer of 1 to 2, and n and m represent an integer of 1 to 3.

Hereinafter, specific examples of the compound having a 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocycle used in the present invention will be illustrated. Among them, the compound having the structure represented by the general formula (A1), (A2), (A1.1), (A1.2) or the compound having the structure represented by the general formula (A3) may be used. preferable. The compound having the 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocycle that can be used in the present invention is not limited by the following specific examples. As described above, the following specific examples may be tautomers, or may form hydrates, solvates or salts.

Next, a method for synthesizing the compound having the structure represented by the general formula (A1) will be described.

The compound having the structure represented by the general formula (A1) can be synthesized by a known method. Among the compounds having the structure represented by the general formula (A1), the compound having a 1,2,4-triazole ring may be any raw material, but a nitrile derivative or an imino ether derivative and a hydrazide derivative may be used. The method of reacting is preferable. The solvent used in the reaction may be any solvent as long as it does not react with the raw materials, but it may be an ester type (for example, ethyl acetate, methyl acetate, etc.), an amide type (dimethylformamide, dimethylacetamide, etc.), or an ether type. (Ethethylene glycol dimethyl ether, etc.), alcohol-based (eg, methanol, ethanol, propanol, isopropanol, n-butanol, 2-butanol, ethylene glycol, ethylene glycol monomethyl ether, etc.), aromatic hydrocarbon-based (eg, toluene, xylene, etc.) ), Water can be mentioned. The solvent used is preferably an alcohol solvent. Further, these solvents may be mixed and used.

The amount of the solvent used is not particularly limited, but is preferably in the range of 0.5 to 30 times, more preferably 1.0 to 25 times the mass of the hydrazide derivative used. Yes, particularly preferably in the range of 3.0 to 20 times the amount.

When the nitrile derivative and the hydrazide derivative are reacted, it is not necessary to use a catalyst, but it is preferable to use a catalyst to accelerate the reaction. As the catalyst to be used, an acid may be used or a base may be used. Examples of the acid include hydrochloric acid, sulfuric acid, nitric acid, acetic acid and the like, and hydrochloric acid is preferable. The acid may be added diluted in water, or may be added by blowing gas into the system. Examples of the base include inorganic bases (potassium carbonate, sodium carbonate, potassium hydrogencarbonate, sodium hydrogencarbonate, potassium hydroxide, sodium hydroxide, etc.) and organic bases (sodium methylate, sodium esterate, potassium methylate, potassium ethyllate, etc.). Sodium butyrate, potassium butyrate, diisopropylethylamine, N, N'-dimethylaminopyridine, 1,4-diazabicyclo [2.2.2] octane, N-methylmorpholin, imidazole, N-methylimidazole, pyridine, etc.) Any of these may be used, and as the inorganic base, potassium carbonate is preferable, and as the organic base, sodium ethylate, sodium ethylate, and sodium butyrate are preferable. The inorganic base may be added as a powder as it is, or may be added in a state of being dispersed in a solvent. Further, the organic base may be added in a state of being dissolved in a solvent (for example, a 28% methanol solution of sodium methylate).

The amount of the catalyst used is not particularly limited as long as the reaction proceeds, but is preferably in the range of 1.0 to 5.0 times the molar amount of the formed triazole ring, and more preferably 1.05 to 3. It is preferably in the range of 0 times the molar amount.

When the imino ether derivative and the hydrazide derivative are reacted, it is not necessary to use a catalyst, and the desired product can be obtained by heating in a solvent.

The method for adding the raw material, the solvent and the catalyst used in the reaction is not particularly limited, and the catalyst may be added last or the solvent may be added last. Further, a method in which the nitrile derivative is dispersed or dissolved in a solvent, a catalyst is added, and then the hydrazide derivative is added is also preferable.

The solution temperature during the reaction may be any temperature as long as the reaction proceeds, but is preferably in the range of 0 to 150 ° C, more preferably in the range of 20 to 140 ° C. Alternatively, the reaction may be carried out while removing the generated water.

Any means may be used for treating the reaction solution, but when a base is used as a catalyst, a method of adding an acid to the reaction solution to neutralize the reaction solution is preferable. Examples of the acid used for neutralization include hydrochloric acid, sulfuric acid, nitric acid, acetic acid and the like, and acetic acid is particularly preferable. The amount of the acid used for neutralization is not particularly limited as long as the pH of the reaction solution is in the range of 4 to 9, but it is preferably 0.1 to 3 times the molar amount of the base used, and particularly preferably. , 0.2 to 1.5 times the molar range.

As a method for treating the reaction solution, when extraction is performed using an appropriate organic solvent, a method in which the organic solvent is washed with water after extraction and then concentrated is preferable. The appropriate organic solvent referred to here is a water-insoluble solvent such as ethyl acetate, toluene, dichloromethane, or ether, or a mixed solvent of the water-insoluble solvent and a tetrahydrofuran or alcohol solvent, and is preferable. Ethyl acetate.

When a compound having a structure represented by the general formula (A1) is crystallized, there is no particular limitation, but a method of adding water to the neutralized reaction solution for crystallization or a method represented by the general formula (A1). A method of neutralizing and crystallizing an aqueous solution in which a compound having the above-mentioned structure is dissolved is preferable.

For example, Exemplified Compound 1 can be synthesized by the following scheme.

(Synthesis of Exemplified Compound 1)

To 350 ml of n-butanol, 77.3 g (75.0 mmol) of benzonitrile, 34.0 g (25.0 mmol) of benzoylhydrazine, and 107.0 g (77.4 mmol) of potassium carbonate were added, and the mixture was stirred at 120 ° C. for 24 hours under a nitrogen atmosphere. bottom. The reaction mixture was cooled to room temperature, the precipitate was filtered, and the filtrate was concentrated under reduced pressure. 20 ml of isopropanol was added to the concentrate, and the precipitate was collected by filtration. The collected precipitate was dissolved in 80 ml of methanol, 300 ml of pure water was added, and acetic acid was added dropwise until the pH of the solution reached 7. The precipitated crystals were collected by filtration, washed with pure water, and air-dried at 50 ° C. to obtain 38.6 g of Exemplified Compound 1. The yield was 70% based on benzoylhydrazine.

^{The 1} H-NMR spectrum of the obtained Exemplified Compound 1 is as follows.

^{1 1} H-NMR (400 MHz, solvent: heavy DMSO, standard: tetramethylsilane) δ (ppm): 7.56 to 7.48 (6H, m), 7.62 to 7.61 (4H, m)
(Synthesis of Exemplified Compound 6)
Exemplified compound 6 can be synthesized by the following scheme.

To 40 ml of n-butanol, 2.5 g (19.5 mmol) of 1,3-dicyanobenzene, 7.9 g (58.5 mmol) of benzoylhydrazine, and 9.0 g (68.3 mmol) of potassium carbonate were added, and the temperature was 120 ° C. under a nitrogen atmosphere. Was stirred for 24 hours. After cooling the reaction solution, 40 ml of pure water was added, and the mixture was stirred at room temperature for 3 hours, and the precipitated solid was separated by filtration and washed with pure water. Water and ethyl acetate were added to the obtained solid to separate the liquids, and the organic layer was washed with pure water. The organic layer was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The obtained crude crystals were purified by silica gel chromatography (ethyl acetate / heptane) to obtain 5.5 g of Exemplified Compound 6. The yield was 77% based on 1,3-dicyanobenzene.

^{The 1} H-NMR spectrum of the obtained Exemplified Compound 6 is as follows.

^{1 1} H-NMR (400 MHz, solvent: heavy DMSO, standard: tetramethylsilane) δ (ppm): 8.83 (1H, s), 8.16 to 8.11 (6H, m), 7.67 to 7 .54 (7H, m)
(Synthesis of Exemplified Compound 176)
Exemplified compound 176 can be synthesized by the following scheme.

80 g (0.67 mol) of acetophenone and 52 g (0.27 mol) of dimethyl isophthalate were added to 520 ml of dehydrated tetrahydrofuran, and 52.3 g (1.34 mol) of sodium amide was added dropwise little by little while stirring with ice water cooling under a nitrogen atmosphere. .. After stirring under ice-water cooling for 3 hours, the mixture was stirred under water-cooling for 12 hours. After neutralizing the reaction solution by adding concentrated sulfuric acid, pure water and ethyl acetate were added to separate the layers, and the organic layer was washed with pure water. The organic layer was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. Methanol was added to the obtained crude crystals and the suspension was washed to obtain 55.2 g of Intermediate A.

55 g (0.15 mol) of Intermediate A was added to 300 ml of tetrahydrofuran and 200 ml of ethanol, and 18.6 g (0.37 mol) of hydrazine monohydrate was added dropwise at room temperature with stirring. After completion of the dropping, the mixture was heated under reflux for 12 hours. Pure water and ethyl acetate were added to the reaction solution to separate the layers, and the organic layer was washed with pure water. The organic layer was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The obtained crude crystals were purified by silica gel chromatography (ethyl acetate / heptane) to obtain 27 g of Exemplified Compound 176.

^{The 1} H-NMR spectrum of the obtained exemplary compound 176 is as follows. In order to avoid complicating the chemical shift due to the presence of the tautomer, several drops of trifluoroacetic acid were added to the measurement solvent for measurement.

^{1 1} H-NMR (400 MHz, solvent: heavy DMSO, reference: tetramethylsilane) δ (ppm): 8.34 (1H, s), 7.87 to 7.81 (6H, m), 7.55 to 7 .51 (1H, m), 7.48-7.44 (4H, m), 7.36-7.33 (2H, m), 7.29 (1H, s)
Other compounds can be synthesized by the same method.

<About the method of using the compound having the structure represented by the general formula (A1)>
The compound having the structure represented by the general formula (A1) used in the present invention can be contained in the acrylic resin film in an appropriate amount, but the addition amount is 0. It is preferably contained in an amount of 1 to 10% by mass, and particularly preferably 0.5 to 5% by mass. Within this range, it is possible to reduce the fluctuation of the phase difference depending on the change in the environmental humidity without impairing the mechanical strength of the acrylic resin film according to the present invention.

Further, as a method of adding the compound having the structure represented by the general formula (A1), the compound may be added as a powder to the resin forming the acrylic resin film, and after being dissolved in a solvent, the acrylic resin film is formed. It may be added to the resin to be used.

(7) Organic Ester In the acrylic resin film according to the present invention, it is preferable to use the following organic ester as a plasticizer from the viewpoint of moldability and dimensional stability.

The organic ester is preferably a compound having a melting point in the range of −60 to 120 ° C., and an organic ester having a 1% mass loss temperature Td1 in the range of 100 to 350 ° C. by differential thermal / thermogravimetric measurement. It is preferable to have. The organic ester is not particularly limited, but it is preferable that the organic ester is at least one selected from a sugar ester, a polyhydric ester, and a polyhydric alcohol ester, and the polycondensate ester is It is preferable that the ester does not contain a nitrogen atom in the structure.

(Measurement of melting point of organic ester)
The melting point was measured using an EXSTAR6220TG / DTA, a differential thermal / thermogravimetric simultaneous measuring device manufactured by Seiko Instruments Inc. The melting point was determined from the endothermic and exothermic peaks when 10 mg of the sample compound was placed in an aluminum pan and the temperature was changed to 30 to 350 ° C. and 350 to 30 ° C. at 10 ° C./min. When measuring a compound having a melting point of 0 ° C. or lower, the melting point was determined from the endothermic / exothermic peaks at temperatures of −50 to 30 ° C. and 30 to −50 ° C. at 5 ° C./min.

The organic ester used in the present invention needs to have a melting point in the range of −60 to 120 ° C., preferably in the range of −45 to 90 ° C. in order to exhibit the effect of the present invention.

When the melting point of the organic ester is in the range of −60 to 120 ° C., it scatters in the production line and is easily liquefied after being cooled. Therefore, it is preferable to be within this range from the viewpoint of exhibiting the effect of the present invention. ..

(Measurement of 1% mass loss temperature of organic ester)
For the measurement of the 1% mass reduction temperature Td1 of the organic ester, for example, 10 mg of the sample compound is put in an aluminum pan by EXSTAR6200TG / DTA, a differential thermal / thermal weight simultaneous measuring device manufactured by Seiko Instruments, and the temperature is 100 ° C. at 50 ° C./min. After raising the temperature to 1%, heat it as it is for 40 minutes, then monitor the mass fluctuation while raising the temperature to 400 ° C at 10 ° C / min, and the temperature when the mass decreases by 1% by mass is defined as the 1% mass decrease temperature. do. The measurement is performed under dry air (dew point −30 ° C.).

The organic ester used in the present invention preferably has a 1% mass reduction temperature in the range of 100 to 300 ° C, more preferably in the range of 200 to 270 ° C, in order to exhibit the effect of the present invention. ..

When the 1% mass reduction temperature of the organic ester is 100 ° C. or higher, the viscosity when scattered and liquefied after cooling is appropriate, and the bulkiness of the scattered matter of the nitrogen-containing heterocyclic compound can be reduced. When the% mass reduction temperature is 350 ° C. or lower, the amount required to reduce the bulkiness of the scattered matter of the nitrogen-containing heterocyclic compound is scattered, and a sufficient effect can be obtained.

Hereinafter, sugar esters, polycondensation esters, and polyhydric alcohol esters will be described as organic esters preferably used in the present invention.

In the present invention, a compound having the above melting point and 1% mass reduction temperature Td1 within the range of the present invention can be appropriately selected and used from the following preferable organic esters.

(7-1) Sugar Ester The sugar ester used in the present invention is a sugar having at least one or more and 12 or less pyranose rings or furanose rings and esterifying all or part of the OH groups having the structure. It is preferably an ester.

The sugar ester used in the present invention is a compound containing at least one of a furanose ring and a pyranose ring, and may be a monosaccharide or a polysaccharide in which 2 to 12 sugar structures are linked. The sugar ester is preferably a compound in which at least one of the OH groups of the sugar structure is esterified. In the sugar ester according to the present invention, the average transesterification degree is preferably in the range of 4.0 to 8.0, and more preferably in the range of 5.0 to 7.5.

The sugar ester used in the present invention is not particularly limited, and examples thereof include sugar esters represented by the following general formula (B).

General formula (B)
(HO) _m- G- (OC (= O) -R ² ) _n
In the above general formula (B), G represents a residue of a monosaccharide or a disaccharide, R ² represents an aliphatic group or an aromatic group, and m represents a residue of a monosaccharide or a disaccharide directly attached. N is the total number of hydroxy groups that are directly attached to the residue of the monosaccharide or disaccharide-(OC (= O) -R ² ) groups. 3 ≦ m + n ≦ 8 and n ≠ 0.

Sugar ester having a structure represented by the general formula (B), the number of hydroxy groups (m), - (O- C (= O) -R 2) group number (n) is a single species which is fixed It is difficult to isolate as a compound, and it is known that several kinds of components having different m and n in the formula are mixed to form a compound. Therefore, the performance as a mixture in which the number of hydroxy groups (m) and the number of-(OC (= O) -R ² ) groups (n) are changed is important, and the acrylic resin film according to the present invention has different performance. In this case, a sugar ester having an average ester substitution degree in the range of 5.0 to 7.5 is preferable.

In the above general formula (B), G represents a residue of a monosaccharide or a disaccharide. Specific examples of monosaccharides include allose, altrose, glucose, mannose, growth, idose, galactose, tarose, ribose, arabinose, xylose, lyxose and the like.

Hereinafter, specific examples of the compound having a monosaccharide residue of the sugar ester represented by the general formula (B) will be shown, but the present invention is not limited to these exemplified compounds.

Specific examples of the disaccharide residue include trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, and isotrehalose.

Hereinafter, specific examples of the compound having a disaccharide residue of the sugar ester represented by the general formula (B) will be shown, but the present invention is not limited to these exemplified compounds.

In the general formula (B), R ² represents an aliphatic group or an aromatic group. Here, the aliphatic group and the aromatic group may each have an independent substituent.

Further, in the general formula (B), m is the total number of hydroxy groups directly bonded to the residue of the monosaccharide or disaccharide, and n is the total number of hydroxy groups directly bonded to the residue of the monosaccharide or disaccharide. It is the total number of-(OC (= O) -R ^{2) groups.} And it is necessary that 3 ≦ m + n ≦ 8, and it is preferable that 4 ≦ m + n ≦ 8. Also, n ≠ 0. Incidentally, when n is 2 or more, - (O-C (= O) -R 2) groups may be different or may be equal to each other.

Aliphatic group in the definition of R ² may be a straight chain, be branched, may be cyclic, preferably one having 1 to 25 carbon atoms, more preferably having 1 to 20, 2 ~ 15 are particularly preferable. Specific examples of the aliphatic group include, for example, methyl, ethyl, n-propyl, iso-propyl, cyclopropyl, n-butyl, iso-butyl, tert-butyl, amyl, iso-amyl, tert-amyl, n-. Examples thereof include hexyl, cyclohexyl, n-heptyl, n-octyl, bicyclooctyl, adamantyl, n-decyl, tert-octyl, dodecyl, hexadecyl, octadecyl, didecyl and the like.

Further, the ^{aromatic group in the definition of R 2} may be an aromatic hydrocarbon group, an aromatic heterocyclic group, and more preferably an aromatic hydrocarbon group. The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, and more preferably 6 to 12 carbon atoms. Specific examples of the aromatic hydrocarbon group include rings of benzene, naphthalene, anthracene, biphenyl, terphenyl and the like. As the aromatic hydrocarbon group, a benzene ring, a naphthalene ring and a biphenyl ring are particularly preferable. As the aromatic heterocyclic group, a ring containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom is preferable. Specific examples of the heterocycle include, for example, furan, pyrrol, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazole, indole, indazole, purine, thiazolin, thiadiazol, oxazolin, oxazole, oxazole, quinoline, Examples thereof include rings of isoquinoline, phthalazine, naphthylidine, quinoxalin, quinazoline, cinnoline, pteridine, aclysine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, tetrazineden and the like. As the aromatic heterocyclic group, a pyridine ring, a triazine ring and a quinoline ring are particularly preferable.

Next, preferred examples of the sugar ester represented by the general formula (B) are shown below, but the present invention is not limited to these exemplified compounds. All of the following exemplified compounds have a melting point and a 1% mass reduction temperature Td1 within the scope of the present invention.

The sugar ester may contain two or more different substituents in one molecule, may contain an aromatic substituent and an aliphatic substituent in one molecule, and may contain two or more different aromatic substituents. Two or more different aliphatic substituents contained in one molecule can be contained in one molecule.

It is also preferable to mix and contain two or more types of sugar esters. It is also preferable to simultaneously contain a sugar ester containing an aromatic substituent and a sugar ester containing an aliphatic substituent.

<Synthesis example: Synthesis example of sugar ester represented by the general formula (B)>
The following is an example of the synthesis of a sugar ester that can be suitably used in the present invention.

34.2 g (0.1 mol) of sucrose, 180.8 g (0.8 mol) of benzoic anhydride, and pyridine in a four-headed corben equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas introduction tube. 379.7 g (4.8 mol) of each was charged, the temperature was raised while bubbling nitrogen gas from the nitrogen gas introduction tube under stirring, and the esterification reaction was carried out at 70 ° C. for 5 hours. Next, the inside of Kolben ^{was depressurized to 4 × 10 2} Pa or less, excess pyridine was distilled off at 60 ° C., then the inside of Kolben was depressurized to 1.3 × 10 Pa or less, and the temperature was raised to 120 ° C. The acid, most of the benzoic acid produced, was distilled off. Then, 1 L of toluene and 300 g of a 0.5 mass% sodium carbonate aqueous solution were added, and the mixture was stirred at 50 ° C. for 30 minutes and then allowed to stand to separate the toluene layer. Finally, 100 g of water was added to the separated toluene layer, washed with water at room temperature for 30 minutes, then the toluene layer was separated, and toluene was distilled off at 60 ° C. ^{under reduced pressure (4 × 10 2 Pa or less).} Mixtures of compounds A-1, A-2, A-3, A-4 and A-5 were obtained. When the obtained mixture was analyzed by HPLC and LC-MASS, A-1 was 7% by mass, A-2 was 58% by mass, A-3 was 23% by mass, A-4 was 9% by mass, and A-5. Was 3% by mass, and the average ester substitution degree of the sugar ester was 6.57. A part of the obtained mixture was purified by silica gel column chromatography to obtain A-1, A-2, A-3, A-4 and A-5 having 100% purity, respectively.

The amount of the sugar ester added is preferably in the range of 0.1 to 20% by mass, more preferably in the range of 1 to 15% by mass with respect to the acrylic resin.

(7-2) Polycondensation Ester In the acrylic resin film according to the present invention, it is possible to use a polycondensation ester having a structure represented by the following general formula (C) as an organic ester for dimensional stability against changes in temperature and humidity. It is preferable from the viewpoint of.

Due to its plastic effect, the polycondensation ester is preferably contained in the range of 1 to 30% by mass, and more preferably in the range of 5 to 20% by mass in the acrylic resin film according to the present invention. ..

General formula (C)
B _3- (G _2- A) _n- G _2- B ₄
In the above general formula (C), B ₃ and B ₄ independently represent an aliphatic or aromatic monocarboxylic acid residue or a hydroxy group, respectively. G ₂ represents an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms. A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms. n represents an integer of 1 or more.

In the present invention, the polycondensation ester is a polycondensation ester containing a repeating unit obtained by reacting a dicarboxylic acid with a diol, A represents a carboxylic acid residue in the polycondensation ester, and G ₂ represents an alcohol residue. show.

The dicarboxylic acid constituting the polycondensation ester is an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid, preferably an aromatic dicarboxylic acid. The dicarboxylic acid may be one kind or a mixture of two or more kinds. In particular, it is preferable to mix aromatics and aliphatics.

The diol constituting the polycondensation ester is an aromatic diol, an aliphatic diol or an alicyclic diol, preferably an aliphatic diol, and more preferably a diol having 1 to 4 carbon atoms. The diol may be one kind or a mixture of two or more kinds.

Among them, it is preferable to contain a repeating unit obtained by reacting at least a dicarboxylic acid containing an aromatic dicarboxylic acid with a diol having 1 to 8 carbon atoms, and a dicarboxylic acid containing an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid. , It is more preferable to contain a repeating unit obtained by reacting with a diol having 1 to 8 carbon atoms.

Both ends of the molecule of the polycondensation ester may or may not be sealed.

Specific examples of the alkylenedicarboxylic acid constituting A of the general formula (C) include 1,2-ethanedicarboxylic acid (succinic acid), 1,3-propanedicarboxylic acid (glutaric acid), and 1,4-butanedicarboxylic acid. It contains divalent groups derived from (adipic acid), 1,5-pentanedicarboxylic acid (pimelic acid), 1,8-octanedicarboxylic acid (sevacinic acid) and the like. Specific examples of the alkenylene dicarboxylic acid constituting A include maleic acid and fumaric acid. Specific examples of the aryldicarboxylic acid constituting A include 1,2-benzenedicarboxylic acid (phthalic acid), 1,3-benzenedicarboxylic acid, 1,4-benzenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and the like. Can be mentioned.

A may be one type or a combination of two or more types. Among them, A is preferably a combination of an alkylene dicarboxylic acid having 4 to 12 carbon atoms and an aryldicarboxylic acid having 8 to 12 carbon atoms.

_{G 2} in the general formula (C) is a divalent group derived from an alkylene glycol having 2 to 12 carbon atoms, a divalent group derived from an aryl glycol having 6 to 12 carbon atoms, or a carbon atom. Represents a divalent group derived from oxyalkylene glycols of numbers 4-12.

Examples of divalent groups derived from alkylene glycols having 2 to 12 carbon atoms in G ₂ include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1 , 3-Butandiol, 1,2-Propylenediol, 2-Methyl-1,3-Propanediol, 1,4-Butanediol, 1,5-Pentanediol, 2,2-Dimethyl-1,3-Propanediol (Neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-di) Methylol heptane), 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2- It contains divalent groups derived from methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol and the like.

Examples of the divalent group derived from an aryl glycol having 6 to 12 carbon atoms in G _2, 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol), 1,4-dihydroxy It contains divalent groups derived from benzene (hydroquinone) and the like. Examples of divalent groups derived from oxyalkylene glycols having 4 to 12 carbon atoms in G are derived from diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and the like. Contains divalent groups.

G ₂ may be one type or a combination of two or more types. Among them, G ₂ is preferably a divalent group derived from an alkylene glycol having 2 to 12 carbon atoms, more preferably 2 to 5, and most preferably 2 to 4.

_{B 3} and B ₄ in the general formula (C) are monovalent groups or hydroxy groups derived from aromatic ring-containing monocarboxylic acids or aliphatic monocarboxylic acids, respectively.

The aromatic ring-containing monocarboxylic acid in the monovalent group derived from the aromatic ring-containing monocarboxylic acid is a carboxylic acid containing an aromatic ring in the molecule, and is not limited to those in which the aromatic ring is directly bonded to the carboxy group. It also includes those in which an aromatic ring is bonded to a carboxy group via an alkylene group or the like. Examples of monovalent groups derived from aromatic ring-containing monocarboxylic acids include benzoic acid, paratershalibutyl benzoic acid, orthotoluic acid, metatoluic acid, paratoluic acid, dimethyl benzoic acid, ethyl benzoic acid, normalpropyl benzoic acid. , Aminobenzoic acid, acetoxybenzoic acid, phenylacetic acid, 3-phenylpropionic acid and the like are included. Of these, benzoic acid and paratoluic acid are preferable.

Examples of monovalent groups derived from aliphatic monocarboxylic acids include acetic acid, propionic acid, butanoic acid, caprylic acid, caproic acid, decanoic acid, dodecanoic acid, stearic acid, oleic acid and the like. Is included. Among them, a monovalent group derived from an alkyl monocarboxylic acid having 1 to 3 carbon atoms in the alkyl moiety is preferable, and an acetyl group (a monovalent group derived from acetic acid) is more preferable.

The weight average molecular weight of the polycondensation ester used in the present invention is preferably in the range of 500 to 3000, and more preferably in the range of 600 to 2000. The weight average molecular weight can be measured by the gel permeation chromatography (GPC).

Hereinafter, specific examples of the polycondensation ester having a structure represented by the general formula (C) will be shown, but the present invention is not limited thereto. All of the following exemplified compounds have a melting point and a 1% mass reduction temperature Td1 within the scope of the present invention.

Hereinafter, specific synthetic examples of the polycondensation ester described above will be described.

<Polycondensation ester P1>
180 g of ethylene glycol, 278 g of phthalic anhydride, 91 g of adipic acid, 610 g of benzoic acid, and 0.191 g of tetraisopropyl titanate as an esterification catalyst were charged into a 2 L four-necked flask equipped with a thermometer, a stirrer, and a slow-speed cooling tube. The temperature is gradually raised with stirring until the temperature reaches 230 ° C. in a nitrogen stream. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted ethylene glycol was distilled off under reduced pressure at 200 ° C. to obtain a polycondensation ester P1. The acid value was 0.20 and the number average molecular weight was 450.

<Polycondensation ester P2>
251 g of 1,2-propylene glycol, 103 g of phthalic anhydride, 244 g of adipic acid, 610 g of benzoic acid, 0.191 g of tetraisopropyl titanate as an esterification catalyst, and a 2 L four-neck equipped with a thermometer, a stirrer, and a slow-speed cooling tube. Place in a flask and gradually raise the temperature in a nitrogen stream until the temperature reaches 230 ° C. with stirring. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200 ° C. to obtain the following polycondensation ester P2. The acid value was 0.10 and the number average molecular weight was 450.

<Polycondensation ester P3>
330 g of 1,4-butanediol, 244 g of phthalic anhydride, 103 g of adipic acid, 610 g of benzoic acid, 0.191 g of tetraisopropyl titanate as an esterification catalyst, and a 2 L four-neck equipped with a thermometer, a stirrer, and a slow-speed cooling tube. Place in a flask and gradually raise the temperature in a nitrogen stream until the temperature reaches 230 ° C. with stirring. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted 1,4-butanediol was distilled off under reduced pressure at 200 ° C. to obtain a polycondensation ester P3. The acid value was 0.50 and the number average molecular weight was 2000.

<Polycondensation ester P4>
251 g of 1,2-propylene glycol, 354 g of terephthalic acid, 610 g of benzoic acid, and 0.191 g of tetraisopropyl titanate as an esterification catalyst were placed in a 2 L four-necked flask equipped with a thermometer, a stirrer, and a slow-speed cooling tube, and nitrogen was charged. The temperature is gradually raised with stirring until the temperature reaches 230 ° C. in the air stream. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200 ° C. to obtain a polycondensation ester P4. The acid value was 0.10 and the number average molecular weight was 400.

<Polycondensation ester P5>
251 g of 1,2-propylene glycol, 354 g of terephthalic acid, 680 g of p-troyl acid, and 0.191 g of tetraisopropyl titanate as an esterification catalyst are charged in a 2 L four-necked flask equipped with a thermometer, a stirrer, and a slow-speed cooling tube. The temperature is gradually raised while stirring until the temperature reaches 230 ° C. in a nitrogen stream. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200 ° C. to obtain the following polycondensation ester P5. The acid value was 0.30 and the number average molecular weight was 400.

<Polycondensation ester P6>
180 g of 1,2-propylene glycol, 292 g of adipate, and 0.191 g of tetraisopropyl titanate as an esterification catalyst were placed in a 2 L four-necked flask equipped with a thermometer, a stirrer, and a slow-speed cooling tube in a nitrogen stream. The temperature is gradually raised with stirring until the temperature reaches 200 ° C. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200 ° C. to obtain a polycondensation ester P6. The acid value was 0.10 and the number average molecular weight was 400.

<Polycondensation ester P7>
180 g of 1,2-propylene glycol, 244 g of phthalic anhydride, 103 g of adipic acid, and 0.191 g of tetraisopropyl titanate as an esterification catalyst are charged in a 2 L four-necked flask equipped with a thermometer, a stirrer, and a slow-speed cooling tube. The temperature is gradually raised while stirring until the temperature reaches 200 ° C. in a nitrogen stream. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200 ° C. to obtain a polycondensation ester P7. The acid value was 0.10 and the number average molecular weight was 320.

<Polycondensation ester P8>
251 g of ethylene glycol, 244 g of phthalic anhydride, 120 g of succinic acid, 150 g of acetic acid, and 0.191 g of tetraisopropyl titanate as an esterification catalyst were placed in a 2 L four-necked flask equipped with a thermometer, a stirrer, and a slow-speed cooling tube, and nitrogen was charged. The temperature is gradually raised with stirring until the temperature reaches 200 ° C. in the air stream. The dehydration condensation reaction was carried out while observing the degree of polymerization. After completion of the reaction, unreacted ethylene glycol was distilled off under reduced pressure at 200 ° C. to obtain a polycondensation ester P8. The acid value was 0.50 and the number average molecular weight was 1200.

<Polycondensation ester P9>
By the same production method as the polycondensation ester P2, the reaction conditions were changed to obtain a polycondensation ester P9 having an acid value of 0.10 and a number average molecular weight of 315.

(7-3) Polyhydric Alcohol Ester The acrylic resin film according to the present invention preferably contains a polyhydric alcohol ester.

The polyhydric alcohol ester is a compound composed of an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. It is preferably a 2 to 20-valent aliphatic polyhydric alcohol ester.

The polyhydric alcohol preferably used in the present invention is represented by the following general formula (D).

General formula (D)
R ₁₁ - _{(OH) n}
However, R ₁₁ represents an n-valent organic group, n represents a positive integer of 2 or more, and an OH group represents an alcoholic and / or phenolic hydroxy group.

Examples of preferable polyhydric alcohols include, for example, the following, but the present invention is not limited thereto.

Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples thereof include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol.

In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

The monocarboxylic acid used for the polyhydric alcohol ester is not particularly limited, and known aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids and the like can be used. It is preferable to use an alicyclic monocarboxylic acid or an aromatic monocarboxylic acid in terms of improving moisture permeability and retention.

Examples of preferable monocarboxylic acids include, but are not limited to, the following.

As the aliphatic monocarboxylic acid, a fatty acid having a linear or side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1 to 20, and particularly preferably 1 to 10. It is preferable to add acetic acid because the compatibility with cellulose acetate increases, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecyl acid, lauric acid, tridecyl acid, and the like. Saturated fatty acids such as myristic acid, pentadecic acid, palmitic acid, heptadecic acid, stearic acid, nonadecanoic acid, araquinic acid, behenic acid, lignoseric acid, cellotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid.

Examples of preferred alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, or derivatives thereof.

Examples of preferable aromatic monocarboxylic acids include those in which 1 to 3 alkoxy groups such as an alkyl group, a methoxy group or an ethoxy group are introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and biphenylcarboxylic acid. Examples thereof include aromatic monocarboxylic acids having two or more benzene rings such as naphthalincarboxylic acid and tetralincarboxylic acid, or derivatives thereof. Benzoic acid is particularly preferred.

The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably in the range of 300 to 1500, and more preferably in the range of 350 to 750. A larger molecular weight is preferable because it is less likely to volatilize, and a smaller molecular weight is preferable in terms of moisture permeability and compatibility with cellulose acylate.

The carboxylic acid used in the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Further, all the OH groups in the polyhydric alcohol may be esterified, or some of them may be left as OH groups.

Specific compounds of the polyhydric alcohol ester are illustrated below. All of the following exemplified compounds have a melting point and a 1% mass reduction temperature Td1 within the scope of the present invention.

The polyhydric alcohol ester used in the present invention is preferably contained in the range of 0.5 to 5% by mass, more preferably 1 to 3% by mass, and 1 to 1 to the acrylic resin film. It is particularly preferable to contain it in the range of 2% by mass.

The polyhydric alcohol ester used in the present invention can be synthesized according to a conventionally known general synthetic method.

(8) Other plasticizers (8-1) Phosphoric acid ester A phosphoric acid ester can be used as the acrylic resin film according to the present invention. Examples of the phosphoric acid ester include triaryl phosphate ester, diaryl phosphate ester, monoaryl phosphate ester, aryl phosphonic acid compound, aryl phosphin oxide compound, condensed aryl phosphoric acid ester, halogenated alkyl phosphate ester, and halogen-containing condensed phosphoric acid. Examples thereof include esters, halogen-containing condensed phosphonic acid esters, and halogen-containing subphosphate esters.

Specific phosphate esters include triphenyl phosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phenylphosphonic acid, tris (β-chloroethyl) phosphate, and tris (dichloro). Examples thereof include propyl) phosphate and tris (tribromoneopentyl) phosphate.

(8-2) Glycolic acid esters In the present invention, glycolic acid esters (glycolate compounds) can be used as one of the polyhydric alcohol esters.

The glycolate compound applicable to the present invention is not particularly limited, but alkylphthalyl alkyl glycolates can be preferably used.

Examples of alkylphthalyl alkyl glycolates include methylphthalylmethylglycolate, ethylphthalylethylglycolate, propylphthalylpropylglycolate, butylphthalylbutylglycolate, octylphthalyloctylglycolate, and methylphthalyl. Ethyl Glycolate, Ethylphthalyl Methyl Glycolate, Ethylphthalylpropyl Glycolate, Methylphthalylbutyl Glycolate, Ethylphthalylbutyl Glycolate, Butylphthalyl Methyl Glycolate, Butylphthalyl EthylGlycolate, Procphthalylbutyl Glycolate, butylphthalylpropylglycolate, methylphthalyloctylglycolate, ethylphthalyloctylglycolate, octylphthalylmethylglycolate, octylphthalylethylglycolate and the like can be mentioned, preferably ethylphthalylethylglycolate. Is.

(9) Ultraviolet absorber The acrylic resin film according to the present invention preferably contains an ultraviolet absorber from the viewpoint of improving light resistance. The ultraviolet absorber aims to improve the light resistance by absorbing ultraviolet rays of 400 nm or less, and in particular, the transmittance at a wavelength of 370 nm is preferably in the range of 2 to 30%, more preferably 4. It is in the range of ~ 20%, more preferably 5-10%.

The ultraviolet absorber preferably used in the present invention is a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and a triazine-based ultraviolet absorber, which are nitrogen-containing heterocyclic compounds, and particularly preferably a benzotriazole-based ultraviolet absorber and benzophenone. It is a system UV absorber.

For example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxyphenyl) -2H-benzotriazole, (2-2H-benzotriazole-2-yl) -6- (straight and side). Chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., and also chinubin 109, chinubin 171, chinubin 234, chinubin 326, chinubin 327, chinubin 328, There are chinubins such as chinubin 928, all of which are commercially available products manufactured by BASF Japan Ltd. and can be preferably used. Of these, halogen-free ones are preferable.

In addition, a disk-shaped compound such as a compound having a 1,3,5-triazine ring is also preferably used as an ultraviolet absorber.

The acrylic resin film according to the present invention preferably contains two or more kinds of ultraviolet absorbers.

Further, as the ultraviolet absorber, a polymer ultraviolet absorber can also be preferably used, and in particular, the polymer type ultraviolet absorber described in JP-A-6-148430 is preferably used. Further, it is preferable that the ultraviolet absorber does not have a halogen group.
Further, it is also preferable to use an ultraviolet absorber and a so-called HALS (hindered amine-based stabilizer) in combination. Examples of HALS include ADEKA STAB LA-52, LA-57, LA-63P, LA-68, LA-72, LA-77, LA-81 (manufactured by ADEKA Corporation), and Tinuvin PA. 144, Tinuvin 765, Tinuvin 770 DF, Tinuvin XT 55 FB, Chimassorb 2020 FDL, Chimassorb 944 FDL, Chimassorb 944 LD, Chimassorb 944 LD, Tinuvin 622 SF (BASF Japan), etc.

The method of adding the ultraviolet absorber is to dissolve the ultraviolet absorber in an alcohol such as methanol, ethanol or butanol, an organic solvent such as methylene chloride, methyl acetate, acetone or dioxolane or a mixed solvent thereof, and then add the ultraviolet absorber to the dope. Alternatively, it may be added directly into the dope composition.

For inorganic powders that do not dissolve in organic solvents, use a dissolver or sandmill in the organic solvent and cellulose acylate to disperse them before adding them to the dope.

The amount of the ultraviolet absorber used is not uniform depending on the type of the ultraviolet absorber, the conditions of use, etc., but when the dry film thickness of the acrylic resin film is 15 to 50 μm, it is 0.5 to 10 with respect to the acrylic resin film. The range of% by mass is preferable, and the range of 0.6 to 4% by mass is more preferable.

(10) Antioxidants Antioxidants are also called deterioration inhibitors. When an electronic device or the like is placed in a high humidity and high temperature state, the acrylic resin film may deteriorate.

The antioxidant has a role of delaying or preventing the decomposition of the acrylic resin film due to, for example, halogen in the residual solvent amount in the acrylic resin film, phosphoric acid of the phosphoric acid-based plasticizer, or the like. It is preferable to contain it in the acrylic resin film.

As such an antioxidant, a hindered phenol-based compound is preferably used, for example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di). -T-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino)- 1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t) -Butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4 , 6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, Tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate and the like.

In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3 -(3-T-Butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred. Further, for example, a hydrazine-based metal inactivating agent such as N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine or Tris (2,4-di-). A phosphorus-based processing stabilizer such as t-butylphenyl) phosphite may be used in combination.

The amount of these compounds added is preferably in the range of 1 ppm to 1.0% in terms of mass ratio with respect to the acrylic resin film, and more preferably in the range of 10 to 1000 ppm.
In particular, when a return material is used, the influence of resin deterioration due to heat history becomes large, so it is preferable to use the above-mentioned antioxidant.

(11) Phase difference control agent In order to improve the display quality of an image display device such as a liquid crystal display device, a retardation control agent is added to an acrylic resin film, or an alignment film is formed to provide a liquid crystal layer, and a polarizing plate is provided. By combining the phase difference derived from the protective film and the liquid crystal layer, it is possible to impart optical compensation ability to the acrylic resin film.

Examples of the phase difference control agent include aromatic compounds having two or more aromatic rings as described in European Patent No. 911656A2, rod-shaped compounds described in JP-A-2006-2025, and the like. Further, two or more kinds of aromatic compounds may be used in combination. The aromatic ring of this aromatic compound is preferably an aromatic heterocycle containing an aromatic heterocycle in addition to the aromatic hydrocarbon ring. Aromatic heterocycles are generally unsaturated heterocycles. Of these, the 1,3,5-triazine ring described in JP-A-2006-2026 is preferable.

The compound having the structure represented by the general formula (A1) also functions as a retardation control agent. Therefore, a compound having a structure represented by the general formula (A1) can be provided with both functions of phase difference control and suppression of optical value fluctuations with respect to humidity fluctuations with one compound.

The amount of these retardation control agents added is preferably in the range of 0.5 to 20% by mass, more preferably in the range of 1 to 10% by mass with respect to 100% by mass of the acrylic resin. ..

(12) Peeling Accelerator Many of the additives that reduce the peeling resistance of the acrylic resin film have a remarkable effect on the surfactant, and the preferable peeling agent is a phosphoric acid ester-based surfactant, a carboxylic acid or a carboxylic acid. Salt-based surfactants, sulfonic acid or sulfonate-based surfactants, and sulfate ester-based surfactants are effective. Further, a fluorine-based surfactant in which a part of hydrogen atoms bonded to the hydrocarbon chain of the above-mentioned surfactant is replaced with a fluorine atom is also effective. The release agent is illustrated below.
RZ-1 C ₈ H ₁₇ OP (= O)-(OH) ₂
RZ-2 C ₁₂ H ₂₅ OP (= O)-(OK) ₂
RZ-3 C ₁₂ H ₂₅ OCH ₂ CH ₂ OP (= O)-(OK) ₂
RZ-4 C ₁₅ H ₃₁ (OCH ₂ CH ₂ ) ₅ O-P (= O)-(OK) ₂
RZ-5 {C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₅ } _2- P (= O) -OH
RZ-6 {C ₁₈ H ₃₅ (OCH ₂ CH ₂ ) ₈ O} _2- P (= O) -ONH _{4
RZ-7 (t-C 4} H 9) 3 -C 6 H 2 -OCH 2 CH 2 O-P (= O) - (OK) 2 RZ-8 (iso-C 9 H 19 -C 6 H 4 - O- (CH ₂ CH ₂ O) _5- P (= O)-(OK) (OH)
RZ-9 C ₁₂ H ₂₅ SO ₃ Na
RZ-10 C ₁₂ H ₂₅ OSO ₃ Na
RZ-11 C ₁₇ H ₃₃ COOH
RZ-12 C ₁₇ H ₃₃ COOH ・ N (CH ₂ CH ₂ OH) ₃
RZ-13 iso-C ₈ H _17- C ₆ H _4- O- (CH ₂ CH ₂ O) _3- (CH ₂ ) ₂ SO ₃ Na
RZ-14 (iso-C ₉ H ₁₉ ) _2- C ₆ H _3- O- (CH ₂ CH ₂ O) _3- (CH ₂ ) ₄ SO ₃ Na
RZ-15 Sodium Triisopropyl Naphthalene Sulfonate RZ-16 Tri-t-Butyl Naphthalene Sodium Luphonate RZ-17 C ₁₇ H ₃₃ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ Na
RZ-18 C ₁₂ H _25- C ₆ H ₄ SO ₃・ NH ₄
The amount of the peeling accelerator added is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, and most preferably 0.1 to 0.5% by mass with respect to the acrylic resin.

≪Physical characteristics of acrylic resin film≫
(1) Thickness of Acrylic Resin Film The thickness of the finished (after drying) acrylic resin film of the present invention varies depending on the purpose of use, but is usually in the range of 5 to 500 μm, preferably in the range of 10 to 150 μm, and is a liquid crystal display. It is preferably 20 to 110 μm for a display device, and particularly preferably 20 to 60 μm in consideration of recent thinning.

The film thickness is adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, etc. so as to obtain the desired thickness and the thickness distribution according to the present invention. Should be adjusted. The width of the acrylic resin film obtained as described above is preferably in the range of 0.5 to 4 m, more preferably in the range of 0.6 to 3 m, and further preferably in the range of 0.8 to 2.5 m. The length is preferably in the range of 100 to 10000 m per roll, more preferably in the range of 500 to 9000 m, and even more preferably in the range of 1000 to 8000 m.

(2) Optical Properties of Acrylic Resin Film The preferable optical properties of the acrylic resin film according to the present invention differ depending on the use of the film. In the case of a polarizing plate protective film application, the absolute value of the in-plane retardation (Ro) is preferably 10 nm or less, more preferably 5 nm or less. The absolute value of retardation (Rt) in the thickness direction is also preferably 50 nm or less, more preferably 35 nm or less, and particularly preferably 10 nm or less.

When an acrylic resin film is used as an optical compensation film (phase difference film), the range of Ro and Rt differs depending on the type of the retardation film, and there are various needs, but 0 nm ≤ Ro ≤ 100 nm and 40 nm ≤ Rt ≤ 400 nm. Is preferable. In the TN mode, 0 nm ≦ Ro ≦ 20 nm and 40 nm ≦ Rt ≦ 80 nm, in the IPS mode, 0 nm ≦ Ro ≦ 20 nm and -30 nm ≦ Rt ≦ 30 nm, and in the VA mode, 20 nm ≦ Ro ≦ 80 nm and 80 nm ≦ Rt ≦ 400 nm are more preferable. The preferable range in the VA mode is 30 nm ≦ Ro ≦ 75 nm and 120 nm ≦ Rt ≦ 250 nm, and when compensating with one retardation film, 50 nm ≦ Ro ≦ 75 nm and 180 nm ≦ Rt ≦ 250 nm, two phase differences. When compensating with a film, 30 nm ≤ Ro ≤ 60 nm and 80 nm ≤ Rt ≤ 140 nm are more preferable in the case of the VA mode compensating film in terms of color shift at the time of black display and contrast viewing angle dependence. be.

The acrylic resin film according to the present invention can realize desired optical properties by appropriately adjusting the process conditions such as the polymer structure used, the type and amount of the additive, the draw ratio, and the residual volatile matter at the time of peeling. .. For example, by adjusting the amount of residual solvent at the time of peeling within 40 to 85% by mass, it is possible to widely control the retardation Rt in the thickness direction to 180 to 300 nm. Generally, the larger the amount of residual solvent at the time of peeling, the smaller the Rt, and the smaller the amount of the residual solvent at the time of peeling, the larger the Rt. For example, by shortening the drying time on a metal endless support and increasing the amount of residual solvent at the time of peeling, the plane orientation can be relaxed and the Rt can be freely lowered, and by adjusting the process conditions. It is possible to develop various retardations according to various uses.

(Retention, Ro, Rt)
In the present specification, Ro and Rt represent in-plane retardation at wavelength λ and retardation in the thickness direction, respectively. Ro is measured by KOBRA 21ADH (manufactured by Oji Measuring Instruments Co., Ltd.) by incident light having a wavelength of λ nm in the normal direction of the film. Rt was measured by injecting light having a wavelength of λ nm from a direction inclined by + 40 ° with respect to the film normal direction with the slow axis in the plane (determined by KOBRA 21ADH) as the inclination axis (rotation axis). A total of three retardation values, the retardation value and the retardation value measured by injecting light with a wavelength of λ nm from a direction inclined by -40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). KOBRA 21ADH is calculated based on the retardation value measured in the direction. Here, as the assumed value of the average refractive index, the values in the Polymer Handbook (JOHN WILEY & SONS, INC) and the catalogs of various optical films can be used. If the average refractive index value is unknown, it can be measured with an Abbe refractometer. By inputting these assumed values of the average refractive index and the film thickness, KOBRA 21ADH calculates nx, ny, and nz, and calculates the retardation based on the following equations (i) and (ii).

Equation (i): Ro = (n _{x −} n _y ) × d (nm)
Equation (ii): Rt = {(n _x + _ny ) /2-n _z } × d (nm)
(In the formula, Ro represents the in-plane retardation value in the film, Rt represents the retardation value in the thickness direction in the film, d represents the thickness (nm) of the optical film, and n _{x represents.} represents the maximum refractive index in the plane of the film, also referred to as a slow axis direction of the refractive index .n _y represents a refractive index in the direction perpendicular to the slow axis in the film plane, n _z is the film in the thickness direction Represents the refractive index of. Both are measured values at a wavelength of 590 nm.)
The photoelastic modulus of the acrylic resin film according to the present invention ^{is preferably 10 × 10 -12} / Pa or less, and more preferably 3 × 10 ^-12 / Pa or less.

(3) Total light transmittance and haze The acrylic resin film according to the present invention is characterized by high transparency, but the total light transmittance measured after humidity control in an environment of 23 ° C. and 55% RH. Is 80% or more, preferably 85% or more, more preferably 90% or more, and particularly preferably 95% or more. The total light transmittance can be measured according to JIS7573 "Plastic-How to determine the total light transmittance and the total light reflectance".

The internal haze of the acrylic resin film according to the present invention is preferably less than 1%, more preferably less than 0.5%. By setting the haze to less than 1%, there is an advantage that the transparency of the film becomes higher and it becomes easier to use as a film for optical applications. Further, when it is less than 0.1%, it is particularly preferably used as a film inside the polarizing element of the liquid crystal display (inside the cross Nicol composed of two polarizing elements) because it does not cause polarization elimination due to light scattering. Be done.
The measurement of internal haze is usually performed by applying a liquid having a refractive index equivalent to that of the film and covering it with smooth glass in order to cancel the surface scattering of the film. The measurement is performed with a haze meter (1001DP type, manufactured by Nippon Denshoku Kogyo Co., Ltd.) after adjusting the humidity of the sample film in an environment of 23 ° C. and 55% RH for 5 hours or more.
The total light transmittance, haze and internal haze can be adjusted to a preferable range basically by removing the scattering substance in the film. It is also preferable to adjust the refractive index of the additive material to the resin of the film so as not to become a scattering substance. In order to keep the surface of the film smooth so as not to cause surface scattering, it is also preferable to adjust the surface roughness of the casting belt and the transport roll that comes into contact with it, and to adjust the surface shape change due to stretching by the stretching temperature, magnification, etc. Will be.

(4) Yellow Index The yellow index (specified in JIS K 7373) of the acrylic resin film according to the present invention is preferably less than 3.0. More preferably, it is less than 1.0. Further, the amount of change in the yellow index (so-called ΔYI) when the film is stored at high temperature and high humidity or exposed to ultraviolet rays is preferably less than 5.0.
In order to adjust the yellow index and ΔYI to a preferable range, the type and amount of coloring additives such as UV absorbers can be adjusted, the decomposition and reactive impurities of resins and additives can be reduced as much as possible, and coloring can be performed. It is preferably carried out by adding an antioxidant or an ultraviolet absorber for prevention.

(5) Equilibrium Moisture Content The acrylic resin film according to the present invention preferably has an equilibrium water content of 3% or less at 25 ° C. and a relative humidity of 60%, and more preferably 1% or less. By setting the equilibrium water content to 3% or less, it is preferable that the humidity changes are easily accommodated and the optical characteristics and dimensions are less likely to change.

For the equilibrium moisture content, the sample film was left in a room conditioned at 23 ° C and 20% relative humidity for 4 hours or more, and then left in a room conditioned at 23 ° C and 80% RH for 24 hours, and the sample was left in a trace amount of water. Moisture is dried and vaporized at a temperature of 150 ° C. using a meter (for example, CA-20 type manufactured by Mitsubishi Chemical Corporation), and then quantified by the curl fisher method.

(6) Moisture Permeability The moisture permeability of the acrylic resin film according to the present invention (specified in JIS K 7129) is preferably 200 g / m ² · d (40 ° C., 90% RH) or less. The polarizer protective film is preferably in the range of 50~200g / m 2 · ^d to keep proper moisture polarizer, is preferably less than 50g / m 2 · ^d as other optical films and electronic circuit board films .. Adjusting the film thickness (inversely proportional) is the most effective way to adjust the moisture permeability, but it can also be adjusted by adding a more hydrophilic or hydrophobic additive to the resin of the film. ..

(7) Mechanical Properties The tensile elastic modulus, tensile fracture strength, and tensile fracture elongation (specified in JIS K 7127) of the acrylic resin film according to the present invention are preferably values in the following ranges. Of these, it is particularly effective to adjust the type and amount of rubber particles in order to adjust the tensile fracture elongation.

Preferred range of tensile modulus: 1.5 to 3.0 GPa
More preferred range of tensile modulus: 2.0-2.5 GPa
Preferred range of tensile fracture strength: 30 to 150 MPa
More preferred range of tensile fracture strength: 50-100 MPa
Preferred range of tensile fracture elongation: 2 to 15%
More preferred range of tensile fracture elongation: 4-10%

(8) Dimensional Change The linear expansion coefficient of the acrylic resin film according to the present invention is preferably 50 to 100 ppm / ° C in the range of 30 ° C to 80 ° C. The expansion coefficient with respect to humidity changes is preferably less than 50 ppm /% RH (in the range of 23 ° C. 20% to 23 ° C. 80%).
Further, it is preferable that the dimensional change after long-term storage is small, for example, the dimensional change rate before and after storage of the film stored at 80 ° C. and 90% RH for 500 hours is less than ± 1%, further less than ± 0.3%. It is preferable to have.

≪Use of acrylic resin film≫
The acrylic resin film according to the present invention includes optical films such as a polarizing plate protective film and a retardation film for a liquid crystal display device as a display device and an organic electroluminescence display device, a base film for a touch panel, a gas barrier base film, and the like. It can be suitably used for a base film of the above, a substrate film for nanoimprint, a substrate film for a flexible electronic circuit, and the like.

Hereinafter, a polarizing plate protective film, a polarizing plate, a liquid crystal display device, an organic electroluminescence display device, and a gas barrier film, which are typical applications, will be described.

(1) Polarizing plate protective film and polarizing plate The polarizing plate is at least polarized using the acrylic resin film according to the present invention as a polarizing plate protective film, appropriately surface-treated, and using water glue or an active energy ray-curable adhesive. It is preferably bonded to one side of the child. Similarly, the acrylic resin film according to the present invention can be bonded to the surface of the polarizing element opposite to the surface to which the acrylic resin film is bonded.

Further, it is also preferable that a cellulose acylate film having an optical compensation function of a liquid crystal cell is bonded to a polarizing element on the opposite surface by using a water glue or an active energy ray-curable adhesive. The acrylic resin film according to the present invention is preferable from the viewpoint of providing a polarizing plate having excellent visibility, which is stable to environmental fluctuations and can make the fluctuation of the phase difference with respect to the temperature and humidity of the cellulose acylate film smaller.

When the polarizing plate is used as the polarizing plate on the visible side, it is preferable that the film on the visible side of the polarizing plate is provided with a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, an antifouling layer and the like.
[Polarizer]
The polarizing element, which is the main component of the polarizing plate, is an element that allows only light on the plane of polarization in a certain direction to pass through, and a typical polarizing element currently known is a polyvinyl alcohol-based polarizing film. The polyvinyl alcohol-based polarizing film includes a polyvinyl alcohol-based film dyed with iodine and a polyvinyl alcohol-based film dyed with a dichroic dye.

As the polarizing element, a polarizing element obtained by forming a film of an aqueous polyvinyl alcohol solution and stretching it uniaxially for staining, or dyeing and then uniaxially stretching the film and then subjecting it to durability treatment with a boron compound can be used. The film thickness of the polarizing element is preferably 2 to 30 μm, particularly preferably 2 to 15 μm.

Further, the content of ethylene unit described in JP-A-2003-248123, JP-A-2003-342322, etc. is 1 to 4 mol%, the degree of polymerization is 2000 to 4000, and the degree of saponification is 99.0 to 99.99 mol%. Ethylene-modified polyvinyl alcohol of the above is also preferably used. Of these, an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature of 66 to 73 ° C. is preferably used. The decoder using this ethylene-modified polyvinyl alcohol film is excellent in polarization performance and durability performance, and has less color unevenness, and is particularly preferably used for a large liquid crystal display device.

<Laminated film type polarizing element>
Further, it is preferable that the polarizing plate is a thin film, and it is particularly preferable that the thickness of the polarizing element is in the range of 2 to 15 μm from the viewpoint of achieving both the strength of the polarizing plate and the thinning.

As the polarizing element of such a thin film, a laminated film type polarizing element is produced by the method described in JP-A-2011-160161, Japanese Patent No. 46910205, Japanese Patent No. 4751481, and Japanese Patent No. 4804589. Is preferable.

As an example, it is preferable to use a thin film laminated film type polarizing element (polarizing laminated film) produced by the following steps from the viewpoint of reducing the overall thickness and weight of the polarizing plate.

(Manufacturing method of polarizing laminated film)
The method for producing a polarizing laminated film used in the present invention includes the following steps.
(A) A laminating step of forming a polyvinyl alcohol-based resin layer on one surface of a base film in which a rubber component is dispersed in a thermoplastic resin to obtain a laminated film.
(B) Stretching step of uniaxially stretching a laminated film to obtain a stretched film,
(C) A dyeing step of dyeing a polyvinyl alcohol-based resin layer of a stretched film with a dichroic dye to obtain a dyed film.
(D) A cross-linking step of immersing the polyvinyl alcohol-based resin layer of the dyed film in a solution containing a cross-linking agent to form a cross-linking film to obtain a cross-linked film, and (e) a drying step of drying the cross-linked film. To explain the process,
(A) Laminating Step In this step, a film in which a rubber component is dispersed (blended and dispersed) in a thermoplastic resin is used as a base film, and a polyvinyl alcohol-based resin layer is formed on one surface thereof to obtain a laminated film. Is preferable.

(Base film)
The thermoplastic resin that is the base of the base film is preferably a thermoplastic resin that is excellent in transparency, mechanical strength, thermal stability, stretchability, and the like. Specific examples of such thermoplastic resins include, for example, chain polyolefin resin; cyclic polyolefin resin; (meth) acrylic resin; polyester resin; cellulose acylate resin; polycarbonate resin; polyvinyl alcohol type. Examples thereof include resin; vinyl acetate resin; polyarylate resin; polystyrene resin; polyether sulfone resin; polysulfone resin; polyamide resin; polyimide resin; and a mixture or copolymer thereof.

The rubber component dispersed in the thermoplastic resin is a resin component having rubber elasticity, and is usually uniformly dispersed in the thermoplastic resin as rubber particles. By mixing and dispersing the rubber components, the tear strength of the base film and, by extension, the stretched film can be improved. The rubber component is not particularly limited as long as it is a resin having rubber elasticity, but it is preferably composed of a resin of the same type or similar to the thermoplastic resin used from the viewpoint of compatibility with the thermoplastic resin.

For example, when the thermoplastic resin is a chain polyolefin resin, the rubber component can be a copolymer of two or more kinds of monomers selected from ethylene and α-olefin. In this case, the content (polymerization ratio) of each monomer constituting the copolymer is preferably less than 90% by mass, more preferably less than 80% by mass.

When the thermoplastic resin is a (meth) acrylic resin, it is preferable to contain an acrylic polymer having rubber elasticity as a rubber component from the viewpoint of compatibility. The acrylic polymer is preferably a polymer mainly composed of alkyl acrylate, may be a homopolymer of alkyl acrylate, or has 50% by mass or more of alkyl acrylate and 50% by mass or less of other monomers. It may be a copolymer with.

The blending amount of the rubber component is preferably 5 to 50% by mass, more preferably 10 to 45% by mass of the thermoplastic resin. If the amount of the rubber component is too small, it tends to be difficult to obtain a sufficient effect of improving the tear strength, and if the amount of the rubber component is too large, the handleability of the base film tends to deteriorate.

The method of dispersing the rubber component in the thermoplastic resin is not particularly limited, for example, a method of kneading and dispersing the separately prepared thermoplastic resin and the rubber component (rubber particles) with a plast mill or the like, or the same reaction at the time of preparing the thermoplastic resin. Examples thereof include a reactor blending method in which a rubber component is also prepared in a container to obtain a thermoplastic resin in which the rubber component is dispersed. The reactor blending method is advantageous in improving the degree of dispersion of the rubber component.

(Polyvinyl alcohol resin layer)
Examples of the polyvinyl alcohol-based resin forming the polyvinyl alcohol-based resin layer include polyvinyl alcohol resins and derivatives thereof. Derivatives of polyvinyl alcohol resin include polyvinyl formal, polyvinyl acetal, etc., polyvinyl alcohol resin as olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and alkyl esters of unsaturated carboxylic acids. , Denatured with acrylamide and the like. Among these, it is preferable to use a polyvinyl alcohol resin.

The polyvinyl alcohol-based resin is preferably a completely saponified product. The range of the degree of saponification is preferably in the range of 80.0 to 100.0 mol%, more preferably in the range of 90.0 to 99.5 mol%, and further preferably in the range of 94.0 to 99.0. It is in the range of mol%.

Additives such as a plasticizer and a surfactant may be added to the above-mentioned polyvinyl alcohol-based resin, if necessary. As the plasticizer, a polyol and a condensate thereof can be used, and examples thereof include glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol. The blending amount of the additive is not particularly limited, but it is preferably 20% by mass or less of the polyvinyl alcohol-based resin.

As a method of applying a polyvinyl alcohol-based resin solution to a base film, a wire bar coating method, a reverse coating method, a roll coating method such as a gravure coating method, a spin coating method, a screen coating method, a fountain coating method, a dipping method, and a spray method. It can be appropriately selected from known methods such as. The drying temperature is, for example, in the range of 50 to 200 ° C, preferably in the range of 60 to 150 ° C. The drying time is, for example, in the range of 2 to 20 minutes.

The thickness of the polyvinyl alcohol-based resin layer in the laminated film is preferably 3 μm or more and 50 μm or less, and more preferably 5 μm or more and 45 μm or less. If it is 3 μm or less, it becomes too thin after stretching and the dyeability is significantly deteriorated, and if it exceeds 50 μm, the obtained polarizing laminated film becomes thick.

The thickness of the polyvinyl alcohol-based resin layer as the polarizing element used in the present invention shall be within the range of 2 to 15 μm as the film thickness after the following stretching treatment from the viewpoint of thinning, strength as the polarizing element, and flexibility. Is preferable.

(B) Stretching Step This step is a step of uniaxially stretching a laminated film provided with a base film and a polyvinyl alcohol-based resin layer to obtain a stretched film. The draw ratio of the laminated film can be appropriately selected depending on the desired polarization characteristics, but is preferably in the range of 5 to 17 times the original length of the laminated film, and more preferably 5 to 8 times. It is within the range.

The stretching is preferably a longitudinal stretching in which the laminated film is stretched in the longitudinal direction (film transport direction). Examples of the longitudinal stretching method include an inter-roller stretching method, a compression stretching method, and a stretching method using a tenter. The uniaxial stretching is not limited to the longitudinal stretching treatment, and may be diagonal stretching or the like.

(C) Dyeing Step This step is a step of dyeing the polyvinyl alcohol resin layer of the stretched film with a dichroic dye to obtain a dyed film. Examples of the dichroic dye include iodine and organic dyes. Examples of organic dyes include red BR, red LR, red R, pink LB, rubin BL, Bordeaux GS, sky blue LG, lemon yellow, blue BR, blue 2R, navy RY, green LG, violet LB, and violet B. Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, Direct Sky Blue, Direct First Orange S, First Black, etc. can be used. These dichroic substances may be used alone or in combination of two or more.

When iodine is used as the dichroic dye, it is preferable to further add iodide to the dyeing solution containing iodine because the dyeing efficiency can be further improved. Examples of this iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and iodide. Examples include titanium.

(D) Crosslinking Step In this step, the polyvinyl alcohol-based resin layer of the dyed film obtained by dyeing with a dichroic dye is crosslinked, and the crosslinked film using the polyvinyl alcohol-based resin layer as a polarizing element is obtained. This is the process of obtaining. The cross-linking step can be performed, for example, by immersing the dyeing film in a solution containing a cross-linking agent (cross-linking solution). Conventionally known substances can be used as the cross-linking agent. For example, boron compounds such as boric acid and borax, glyoxal, glutaraldehyde and the like can be mentioned. Only one of these may be used alone, or two or more thereof may be used in combination.

(E) Drying step The obtained crosslinked film is usually washed and then dried. This gives a polarizing laminated film. Cleaning can be performed by immersing the crosslinked film in pure water such as ion-exchanged water and distilled water. The water washing temperature is usually in the range of 3 to 50 ° C, preferably in the range of 4 to 20 ° C. The soaking time is usually in the range of 2 to 300 seconds, preferably 5 to 240 seconds. The washing may be a combination of a washing treatment with an iodide solution and a water washing treatment, and a solution containing liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol, and propanol can also be used as appropriate.

As the drying method, any suitable method (for example, natural drying, blast drying, heat drying) can be adopted. For example, in the case of heat drying, the drying temperature is usually in the range of 20 to 95 ° C., and the drying time is usually about 1 to 15 minutes.

The polarizing laminated film includes a polarizing element layer made of a polyvinyl alcohol-based resin layer in which a dichroic dye is adsorbed and oriented, and can be used as a polarizing plate by itself. In a preferred embodiment of the present invention, after forming a polarizing laminated film by the above steps, the polyvinyl alcohol layer of the polarizing laminated film is peeled off from the base film, so that the polyvinyl alcohol layer is used as a polarizing element. That is. According to this method, the thickness of the polarizing element layer can be reduced to 15 μm or less, so that a thin polarizing element can be obtained. Further, the polarizing element used in the present invention is also excellent in polarization performance and durability.

[Preparation of polarizing plate]
The polarizing plate can be produced by a general method. It is preferable that the polarizing element side of the acrylic resin film according to the present invention is surface-treated and then bonded to the polarizing element produced by dipping and stretching in an iodine solution using the following active energy ray-curable adhesive. When a cellulose acylate film is used on the surface opposite to the surface to which the acrylic resin film is bonded, the cellulose acylate film is subjected to alkali saponification treatment, and at least one surface of the polarizing element is completely saponified. It is preferable to use a modified polyvinyl alcohol aqueous solution (water glue) for bonding. Another polarizing plate protective film can be attached to the other surface.

For example, commercially available cellulose acylate films (eg, Konica Minolta Tuck KC8UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC6UY, KC6UA, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC8 KC8UXW-RHA-NC, KC4UXW-RHA-NC, and above, manufactured by Konica Minolta Co., Ltd.) are preferably used.
In addition, various grades of Cosmoshine (R) super birefringence type (SRF) manufactured by Toyobo Co., Ltd. and cycloolefin polymer (COP) molded product-Zeonoa film (R) manufactured by Nippon Zeon Co., Ltd. are also preferably used.
Further, various acrylic resin films including the acrylic resin film according to the present invention are also preferably used as the polarizing plate protective film used on the opposite surface.

[Active energy ray-curable adhesive]
Further, in the polarizing plate, it is preferable that the acrylic resin film and the polarizing element according to the present invention are bonded together with an active energy ray-curable adhesive.

As the active energy ray-curable adhesive, it is preferable to use the following ultraviolet curable adhesive.

In the present invention, by applying an ultraviolet curable adhesive to bond an acrylic resin film and a polarizing element, it is possible to obtain a polarizing plate having high strength and excellent flatness even in a thin film.

<Composition of UV curable adhesive>
As the ultraviolet curable adhesive composition for a polarizing plate, a photoradical polymerization type composition using photoradical polymerization, a photocationic polymerization type composition using photocationic polymerization, and photoradical polymerization and photocationic polymerization are used in combination. The hybrid type composition is known.

The photoradical polymerization type composition contains a radically polymerizable compound containing a polar group such as a hydroxy group or a carboxy group described in JP-A-2008-09329 and a radically polymerizable compound not containing a polar group in a specific ratio. Composition) and the like are known. In particular, the radically polymerizable compound is preferably a compound having a radically polymerizable ethylenically unsaturated bond. Preferred examples of compounds having a radically polymerizable ethylenically unsaturated bond include compounds having a (meth) acryloyl group. Examples of the compound having a (meth) acryloyl group include N-substituted (meth) acrylamide-based compounds, (meth) acrylate-based compounds, and the like. (Meta) acrylamide means acryamide or methamide.

Further, as the photocationic polymerization type composition, as disclosed in JP-A-2011-028234, (α) a cationically polymerizable compound, (β) a photocationic polymerization initiator, and (γ) a wavelength longer than 380 nm. Examples thereof include an ultraviolet curable adhesive composition containing each component of a photosensitizer exhibiting maximum absorption of light and a (δ) naphthalene-based photosensitizer. However, other ultraviolet curable adhesives may be used.

(I) Pretreatment Step The pretreatment step is a step of easily adhering the adhesive surface of the acrylic resin film to the polarizing element. Examples of the easy-adhesion treatment include corona treatment and plasma treatment.

(Applying process of UV curable adhesive)
In the step of applying the ultraviolet curable adhesive, the ultraviolet curable adhesive is applied to at least one of the adhesive surfaces of the polarizing element and the acrylic resin film. When the ultraviolet curable adhesive is applied directly to the surface of the polarizing element or the acrylic resin film, the application method is not particularly limited. For example, various wet coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used. Further, a method can also be used in which an ultraviolet curable adhesive is spread between the polarizing element and the acrylic resin film, and then pressed with a roller or the like to spread the adhesive uniformly.

(Ii) Laminating Step After applying the ultraviolet curable adhesive by the above method, it is processed in the laminating step. In this bonding step, for example, when the ultraviolet curable adhesive is applied to the surface of the polarizing element in the previous coating step, the acrylic resin film is laminated there. Further, in the case of the method of first applying the ultraviolet curable adhesive to the surface of the acrylic resin film, the polarizing element is superimposed there. Further, when the ultraviolet curable adhesive is cast between the polarizing element and the acrylic resin film, the polarizing element and the acrylic resin film are overlapped in that state. Then, normally, in this state, pressure is applied by sandwiching the acrylic resin film side on both sides with a pressure roller or the like. As the material of the pressure roller, metal, rubber or the like can be used. The pressure rollers arranged on both sides may be made of the same material or may be made of different materials.

(Iii) Curing Step In the curing step, the uncured UV curable adhesive is irradiated with ultraviolet rays to obtain a cationically polymerizable compound (for example, an epoxy compound or an oxetane compound) or a radically polymerizable compound (for example, an acrylate compound or an acrylamide). The ultraviolet curable adhesive layer containing (based compounds, etc.) is cured, and the superposed polarizing element and the acrylic resin film are adhered to each other via the ultraviolet curable adhesive. When the acrylic resin film is attached to one side of the polarizing element, the active energy rays may be emitted from either the polarizing element side or the acrylic resin film side. When the acrylic resin film is attached to both sides of the polarizing element, the acrylic resin film is laminated on both sides of the polarizing element via an ultraviolet curable adhesive, and the acrylic resin film is irradiated with ultraviolet rays to cure the ultraviolet rays on both sides. It is advantageous to cure the adhesive at the same time.

As the ultraviolet irradiation conditions, any appropriate conditions can be adopted as long as the ultraviolet curable adhesive applied to the present invention can be cured. Preferably the dose of ultraviolet rays in the range of 50~1500mJ / cm ² in accumulated light quantity, and even more preferably in the range of 100 to 500 mJ / cm ^2.

When the polarizing plate manufacturing process is performed on a continuous line, the line speed depends on the curing time of the adhesive, but is preferably in the range of 1 to 500 m / min, more preferably in the range of 5 to 300 m / min, and further preferably in the range of 10 to 10 m / min. The range is 100 m / min. When the line speed is 1 m / min or more, productivity can be ensured, damage to the acrylic resin film can be suppressed, and a polarizing plate having excellent durability can be produced. Further, when the line speed is 500 m / min or less, the ultraviolet curable adhesive can be sufficiently cured, and an ultraviolet curable adhesive layer having a desired hardness and excellent adhesiveness can be formed.

[Functional layer]
The acrylic resin film according to the present invention may be provided with an antireflection layer, a light scattering layer, a hardcoat layer, an antistatic layer and the like as functional layers.

<Anti-reflective layer>
It is preferable to provide a functional film such as an antireflection layer on the transparent protective film of the polarizing plate arranged on the opposite side of the liquid crystal cell. An antireflection layer in which at least a light scattering layer and a low refractive index layer are laminated in this order on an acrylic resin film, or a medium refractive index layer, a high refractive index layer, and a low refractive index layer are laminated in this order on an acrylic resin film. An antireflection layer is preferably used.

(Antireflection layer provided with a light scattering layer and a low refractive index layer)
It is preferable that the matte particles are dispersed in the light scattering layer, and the refractive index of the material of the portion other than the matte particles of the light scattering layer is preferably in the range of 1.50 to 2.00, and the low refractive index layer. The refractive index of light is preferably in the range of 1.35 to 1.49. The light scattering layer may have both antiglare and hardcourt properties, may be one layer, or may be composed of a plurality of layers, for example, two to four layers.

The antireflection layer has a centerline average roughness Ra of 0.08 to 0.40 μm, a 10-point average roughness Rz of 10 times or less of Ra, an average mountain valley distance Sm of 1 to 100 μm, and an unevenness deepest. Designed so that the standard deviation of the height of the convex part from the part is 0.5 μm or less, the standard deviation of the average mountain valley distance Sm with respect to the center line is 20 μm or less, and the surface with an inclination angle of 0 to 5 degrees is 10% or more. By doing so, sufficient antiglare property and a uniform matte feeling visually are achieved, which is preferable.

Further, the ratio of the minimum value to the maximum value of the reflectance in the range where the color of the reflected light under the C light source is in ^{the range of a *} value -2 to 2, b ^{* value -3 to 3, 380 to 780 nm is 0.5.} When it is ~ 0.99, the tint of the reflected light becomes neutral, which is preferable. ^{Further, when the b *} value of the transmitted light under the C light source is 0 to 3, the yellowness of the white display when applied to the display device is reduced, which is preferable.

Further, if the standard deviation of the luminance distribution when the luminance distribution is measured on the film by inserting a lattice of 120 × 40 μm between the surface light source and the antireflection film is 20 or less, the present invention applies to the high-definition panel. Glittering when such an acrylic resin film is applied is reduced, which is preferable.

The antireflection layer has optical characteristics of a mirror reflectance of 2.5% or less, a transmittance of 90% or more, and a glossiness of 60 degrees of 70% or less, so that reflection of external light can be suppressed and visibility is improved. Therefore, it is preferable. In particular, the mirror reflectance is more preferably 1% or less, and most preferably 0.5% or less. Haze 20 to 50%, internal haze / total haze value (ratio) 0.3 to 1, decrease in haze value after forming a low refractive index layer from haze value up to the light scattering layer within 15%, comb width 0 By setting the transmittance of the transmitted image at 5.5 mm to 20 to 50% and the transmittance ratio of vertically transmitted light / vertically tilted by 2 degrees to 1.5 to 5.0, glare prevention on high-definition LCD panels and characters It is preferable that the reduction of blurring such as is achieved.

(Low refractive index layer)
The refractive index of the low refractive index layer of the antireflection film is preferably in the range of 1.20 to 1.49, more preferably in the range of 1.30 to 1.44. Further, it is preferable that the low refractive index layer satisfies the following formula in terms of low reflectance.

(M / 4) x 0.7 <n1d1 <(m / 4) x 1.3
In the equation, m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm.

The material forming the low refractive index layer will be described below.

The low refractive index layer preferably contains a fluoropolymer as a low refractive index binder. As the fluoropolymer, a fluoropolymer having a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with water of 90 to 120 °, and a sliding angle of pure water of 70 ° or less, which is crosslinked by heat or ionizing radiation, is preferable. When the antireflection film is attached to an image display device, the lower the peeling force from the commercially available adhesive tape, the easier it is to peel off after attaching a sticker or memo, preferably 500 gf or less, more preferably 300 gf or less, and 100 gf or less. Most preferred.

Further, the higher the surface hardness measured by a micro hardness tester, the less likely it is to be scratched, preferably 0.3 GPa or more, and more preferably 0.5 GPa or more.

Fluorine-containing polymers used for the low refractive index layer include hydrolysis and dehydration condensates of perfluoroalkyl group-containing silane compounds (for example, (Heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). , A fluorine-containing copolymer having a fluorine-containing monomer unit and a constituent unit for imparting a cross-linking reactivity as constituents.

Specific examples of the fluorine-containing monomer include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxol, etc.). ), Partial or fully fluorinated alkyl ester derivatives of (meth) acrylic acid (eg, Viscoat 6FM (manufactured by Osaka Organic Chemistry), M-2020 (manufactured by Daikin), etc.), fully or partially fluorinated vinyl ethers, etc. , Preferably perfluoroolefins, and particularly preferably hexafluoropropylene from the viewpoint of refractive index, solubility, transparency, availability and the like.

As a structural unit for imparting cross-linking reactivity, a structural unit obtained by polymerizing a monomer having a self-crosslinking functional group in the molecule in advance, such as glycidyl (meth) acrylate and glycidyl vinyl ether, a carboxy group, a hydroxy group, and an amino group. , Obtained by polymerization of monomers having a sulfo group (eg, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.) A structural unit in which a cross-linking reactive group such as a (meth) acrylic loyl group is introduced into these structural units by a polymer reaction (for example, it can be introduced by a method such as allowing acrylic acid chloride to act on a hydroxy group). Can be mentioned.

Further, in addition to the above-mentioned fluorine-containing monomer unit and the structural unit for imparting cross-linking reactivity, a monomer containing no fluorine atom can be appropriately copolymerized from the viewpoint of solubility in a solvent, transparency of the film and the like. The monomer unit that can be used in combination is not particularly limited, and for example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.) and acrylic acid esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2). -Ethylhexyl), methacrylic esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl, etc.) Vinyl ethers, ethyl vinyl ethers, cyclohexyl vinyl ethers, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl silicate, etc.), acrylamides (N-tert-butyl acrylamide, N-cyclohexyl acrylamide, etc.), methacrylicamides, acrylonitrile Derivatives and the like can be mentioned. A curing agent may be appropriately used in combination with the above polymer as described in JP-A No. 10-25388 and JP-A No. 10-147739.

(Light scattering layer)
The light scattering layer is generally formed for the purpose of contributing the light diffusivity due to surface scattering and / or internal scattering and the hard coat property for improving the scratch resistance of the film to the film. Therefore, it is generally formed by containing a binder for imparting hard coat property, matte particles for imparting light diffusivity, and an inorganic filler for increasing the refractive index, preventing crosslink shrinkage, and increasing the strength, if necessary. Will be done. The film thickness of the light scattering layer is preferably in the range of 1 to 10 μm, more preferably in the range of 1.2 to 6 μm, from the viewpoint of imparting hard coat property and suppressing the generation of curl and deterioration of brittleness.

The binder of the scattering layer is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a polymer having a saturated hydrocarbon chain as a main chain. Further, the binder polymer preferably has a crosslinked structure. As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as a main chain and having a crosslinked structure, a (co) polymer of a monomer having two or more ethylenically unsaturated groups is preferable. In order to make the binder polymer have a high refractive index, the structure of this monomer contains an aromatic ring or at least one atom selected from a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom. You can also choose.

Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (eg, ethylene glycol di (meth) acrylate). Meta) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropanetri (meth) acrylate, trimethylol ethanetri (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate) , The above-mentioned ethylene oxide modified product, vinylbenzene and its derivatives (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, divinylsulfone). , Acrylate (eg, methylenebisacrylamide) and methacrylicamide. Two or more kinds of the above-mentioned monomers may be used in combination.

Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinylnaphthalene, vinylphenyl sulfide, 4-methacryloxyphenyl-4'-methoxyphenylthioether and the like. Two or more of these monomers may be used in combination.

Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photoradical initiator or a thermal radical initiator.

Therefore, a coating solution containing a monomer having an ethylenically unsaturated group, a photoradical initiator or a thermal radical initiator, mat particles and an inorganic filler is prepared, and the coating solution is applied onto a transparent support and then ionizing radiation or heat. It can be cured by the polymerization reaction according to the above to form an antireflection film. Known photoradical initiators and the like can be used.

The polymer having a polyether as a main chain is preferably a ring-opening polymer of a polyfunctional eposixi compound. Ring-opening polymerization of the polyfunctional Eposiki compound can be carried out by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermoacid generator.

Therefore, a coating solution containing a polyfunctional eposixic compound, a photoacid generator or a thermoacid generator, mat particles and an inorganic filler is prepared, and the coating solution is applied onto a transparent support and then subjected to ionization radiation or a polymerization reaction by heat. It can be cured to form an antireflection film.

A crosslinkable functional group is introduced into the polymer using a monomer having a crosslinkable functional group in place of or in addition to the monomer having two or more ethylenically unsaturated groups, and the reaction of the crosslinkable functional group causes a reaction of the crosslinkable functional group. Crosslinked structures may be introduced into the binder polymer.

Examples of crosslinkable functional groups include isocyanato groups, epoxy groups, aziridine groups, oxazoline groups, aldehyde groups, carbonyl groups, hydrazine groups, carboxy groups, methylol groups and active methylene groups. Metal alkoxides such as vinyl sulfonic acid, acid anhydride, cyanoacrylate derivatives, melamine, etherified methylol, esters and urethanes, tetramethoxysilanes can also be used as monomers for introducing crosslinked structures. A functional group exhibiting crosslinkability as a result of the decomposition reaction may be used, such as a block isocyanate group. That is, in the present invention, the crosslinkable functional group may not show a reaction immediately, but may show a reactivity as a result of decomposition.

These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

The light scattering layer has matte particles larger than the filler particles and an average particle size in the range of 1 to 10 μm, preferably 1.5 to 7.0 μm, for the purpose of imparting antiglare properties, such as particles of an inorganic compound or particles. It is preferable that resin particles are contained.

Specific examples of the matte particles include particles of _{an inorganic compound such as silica particles and TiO 2} particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles are preferable. Can be mentioned. Of these, crosslinked styrene particles, crosslinked acrylic particles, crosslinked acrylic styrene particles, and silica particles are preferable. The shape of the matte particles can be either spherical or amorphous.

Further, two or more kinds of matte particles having different particle sizes may be used in combination. It is possible to impart antiglare properties with matte particles with a larger particle size and to impart different optical properties with matte particles with a smaller particle size.

Further, the particle size distribution of the matte particles is most preferably monodisperse, and the closer the particle size of each particle is to the same, the better. For example, when particles having a particle size 20% or more larger than the average particle size are defined as coarse particles, the ratio of the coarse particles is preferably 1% or less of the total number of particles, more preferably 0.1%. It is less than or equal to, and more preferably 0.01% or less. Matte particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and fine particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

The matte particles are contained in the light scattering layer so that the amount of matte particles in the formed light scattering layer is preferably in ^{the range of 10 to 1000 mg / m 2} , more preferably in the range of 100 to 700 mg / m ^2. The particle size distribution of the matte particles is measured by the Coulter counter method, and the measured distribution is converted into the particle number distribution.

In the light scattering layer, in order to increase the refractive index of the layer, in addition to the above-mentioned matte particles, an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony is used. Therefore, it is preferable that an inorganic filler having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, and more preferably 0.06 μm or less is contained.

On the contrary, in order to increase the difference in the refractive index from the matte particles, it is also preferable to use a silicon oxide in the light scattering layer using the high refractive index matte particles in order to keep the refractive index of the layer low. The preferred particle size is the same as the above-mentioned inorganic filler.

Specific examples of the inorganic filler used in the light scattering layer include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO and SiO ₂ . TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index. The surface of the inorganic filler is preferably treated by silane coupling treatment or titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with the binder species on the filler surface is preferably used. The amount of these inorganic fillers added is preferably in the range of 10 to 90% of the total mass of the light scattering layer, more preferably in the range of 20 to 80%, and particularly preferably in the range of 30 to 75%. be. Since the particle size of such a filler is sufficiently smaller than the wavelength of light, scattering does not occur, and the dispersion in which the filler is dispersed in the binder polymer behaves as an optically uniform substance.

The bulk refractive index of the mixture of the binder and the inorganic filler of the light scattering layer is preferably in the range of 1.48 to 2.00, more preferably in the range of 1.50 to 1.80. In order to keep the refractive index in the above range, the type and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select it can be easily known experimentally in advance.

The light scattering layer is coated with either a fluorine-based or silicone-based surfactant, or both, for forming an antiglare layer, in order to ensure surface uniformity such as coating unevenness, drying unevenness, and point defects. It is preferably contained in the composition. In particular, a fluorine-based surfactant is preferably used because it has the effect of improving surface defects such as uneven coating, uneven drying, and point defects of the antireflection film with a smaller addition amount. The purpose is to improve productivity by providing high-speed application suitability while improving surface uniformity.

<Anti-reflection layer in which a medium refractive index layer, a high refractive index layer, and a low refractive index layer are laminated in this order>
An antireflection film having a layer structure in the order of at least a medium refractive index layer, a high refractive index layer, and a low refractive index layer (outermost layer) on the film shall be designed to have a refractive index satisfying the following relationship. Is preferable. Refractive index of high refractive index layer> Refractive index of medium refractive index layer> Refractive index of transparent support> Refractive index of low refractive index layer. Further, a hard coat layer may be provided between the transparent support and the medium refractive index layer. Further, it may be composed of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer (for example, Japanese Patent Laid-Open Nos. 8-122504, 8-11401, 10-30902, and Japanese Patent Publication No. Kai 2002-243906, Japanese Patent Application Laid-Open No. 2000-111706, etc.). Further, other functions may be imparted to each layer, for example, a low refractive index layer having antifouling property and a high refractive index layer having antistatic property (eg, JP-A-10-206063, JP-A-2002). No. 243906, etc.) and the like.

The haze of the antireflection film is preferably 5% or less, more preferably 3% or less. Further, the strength of the film is preferably H or more, more preferably 2H or more, and most preferably 3H or more in the pencil hardness test according to JIS K5400.

(High-refractive index layer and medium-refractive index layer)
The layer having a high refractive index of the antireflection film is preferably composed of a curable film containing at least an inorganic compound ultrafine particles having a high refractive index having an average particle size of 100 nm or less and a matrix binder.

Examples of the fine particles of the inorganic compound having a high refractive index include inorganic compounds having a refractive index of 1.65 or more, and preferably those having a refractive index of 1.9 or more. For example, oxides of Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, In and the like, composite oxides containing these metal atoms and the like can be mentioned.

In order to obtain such ultrafine particles, the surface of the particles must be treated with a surface treatment agent (for example, silane coupling agent, etc .: JP-A-11-295503, JP-A-11-153703, JP-A-2000-9908. , Anionic compound or organic metal coupling agent: JP-A-2001-310432, etc.), and a core-shell structure having high refractive index particles as a core (: JP-A-2001-166104, JP-A-2001-310432). (Gaz., Etc.), a specific dispersant combination (eg, JP-A-11-153703, US Pat. No. 6,210,858, etc.) and the like can be mentioned.

Examples of the material forming the matrix include conventionally known thermoplastic resins and curable resin films.

Further, from a composition containing a polyfunctional compound having at least two radically polymerizable and / or cationically polymerizable groups, and a composition containing an organic metal compound having a hydrolyzable group and a partial condensate thereof. At least one composition selected is preferred. For example, the compositions described in JP-A-2000-47004, JP-A-2001-315242, JP-A-2001-31871, JP-A-2001-296401 and the like can be mentioned.

Further, a curable film obtained from a colloidal metal oxide obtained from a hydrolyzed condensate of metal alkoxide and a metal alkoxide composition is also preferable. For example, it is described in JP-A-2001-293818.

The refractive index of the high refractive index layer is generally in the range of 1.70 to 2.20. The thickness of the high refractive index layer is preferably in the range of 5 nm to 10 μm, and more preferably in the range of 10 nm to 1 μm. The refractive index of the medium refractive index layer is adjusted so as to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the medium refractive index layer is preferably in the range of 1.50 to 1.70. The thickness is preferably in the range of 5 nm to 10 μm, and more preferably in the range of 10 nm to 1 μm.

(Low refractive index layer)
In the above configuration, the low refractive index layer is sequentially laminated on the high refractive index layer. The refractive index of the low refractive index layer is preferably in the range of 1.20 to 1.55, more preferably in the range of 1.30 to 1.50.

It is preferable to construct it as an outermost layer having scratch resistance and stain resistance. As a means for greatly improving scratch resistance, it is effective to impart slipperiness to the surface, and a conventionally known means for a thin film layer including the introduction of silicone, the introduction of fluorine, or the like can be applied.

The refractive index of the fluorine-containing compound is preferably in the range of 1.35 to 1.50. More preferably, it is in the range of 1.36 to 1.47. Further, the fluorine-containing compound is preferably a compound containing a crosslinkable or polymerizable functional group containing a fluorine atom in the range of 35 to 80% by mass. For example, Japanese Patent Application Laid-Open No. 9-222503 paragraph numbers [0018] to [0026], Japanese Patent Application Laid-Open No. 11-38202, specification paragraph numbers [0019] to [0030], Japanese Patent Application Laid-Open No. 2001-40284, Japanese Patent Application Laid-Open No. Examples thereof include the compounds described in JP-A-2000-284102 and the like.

The silicone compound is a compound having a polysiloxane structure, and preferably contains a curable functional group or a polymerizable functional group in the polymer chain and has a crosslinked structure in the membrane. Examples thereof include reactive silicone (eg, silaplane (manufactured by Chisso Co., Ltd.), polysiloxane containing silanol groups at both ends (Japanese Patent Laid-Open No. 11-258403, etc.) and the like.

The cross-linking or the cross-linking or polymerization reaction of the fluorophore-containing and / or siloxane polymer having a polymerizable group is carried out at the same time as or after the coating of the coating composition for forming the outermost layer containing the polymerization initiator, the sensitizer and the like. It is preferable to carry out by irradiating light or heating.

Further, a solgel cured film in which an organic metal compound such as a silane coupling agent and a silane coupling agent containing a specific fluorine-containing hydrocarbon group are cured by a condensation reaction in the coexistence of a catalyst is also preferable.

For example, a polyfluoroalkyl group-containing silane compound or a partially hydrolyzed condensate thereof (Japanese Patent Laid-Open Nos. 58-142958, 58-147483, 58-1474844, 9-157582, 11). A silyl compound containing a poly "perfluoroalkyl ether" group which is a fluorine-containing long-chain group (compounds described in JP-A-106704) (Japanese Patent Laid-Open Nos. 2000-117902, 2001-48590, 2002-). The compounds described in JP-A-53804, etc.) and the like can be mentioned.

The low refractive index layer has an average primary particle diameter of 1 to 150 nm such as a filler (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)) as an additive other than the above. It can contain a low refractive index inorganic compound, organic fine particles described in paragraphs [0020] to [0038] of JP-A-11-3820), a silane coupling agent, a slip agent, a surfactant and the like.

When the low refractive index layer is located below the outermost layer, the low refractive index layer may be formed by a vapor phase method (vacuum vapor deposition method, sputtering method, ion plating method, plasma CVD method, etc.). The coating method is preferable because it can be manufactured at low cost. The film thickness of the low refractive index layer is preferably in the range of 30 to 200 nm, more preferably in the range of 50 to 150 nm, and most preferably in the range of 60 to 120 nm.

<Other layers of antireflection layer>
Further, a hard coat layer, a backscattering layer, a primer layer, an antistatic layer, an undercoat layer, a protective layer and the like may be provided.

(Hard coat layer)
The hard coat layer is usually provided on the surface of the transparent support in order to impart physical strength to the transparent protective film provided with the antireflection layer. In particular, it is preferable to provide it between the transparent support and the high refractive index layer. The hardcoat layer is preferably formed by a cross-linking reaction or a polymerization reaction of a light and / or heat-curable compound. The curable functional group is preferably a photopolymerizable functional group, and the hydrolyzable functional group-containing organometallic compound is preferably an organoalkoxysilyl compound.

Specific examples of these compounds include those similar to those exemplified for the high refractive index layer. Specific examples of the constituent composition of the hardcoat layer include those described in JP-A-2002-144913, JP-A-2000-9908, International Publication No. 00/46617 and the like.

The high refractive index layer can also serve as a hard coat layer. In such a case, it is preferable to finely disperse the fine particles and contain them in the hard coat layer by using the method described for the high refractive index layer.

The hard coat layer can also serve as an antiglare layer (described later) to which particles having an average particle size in the range of 0.2 to 10 μm are contained to impart an antiglare function (antiglare function).

The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably in the range of 0.2 to 10 μm, more preferably in the range of 0.5 to 7 μm.

The strength of the hard coat layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in the pencil hardness test according to JIS K5400. Further, in the tabor test according to JIS K5400, it is preferable that the amount of wear of the test piece before and after the test is small.

(Antistatic layer)
When the antistatic layer is provided, it is preferable to impart conductivity ^{having a volume resistivity of 10-8} Ω · cm ^{-3 or less. It is possible to impart a volume resistivity of 10-8} Ω · cm ^-3 by using hygroscopic substances, water-soluble inorganic salts, certain surfactants, cationic polymers, anionic polymers, colloidal silica, etc., but the temperature and humidity can be increased. There is a problem that sufficient conductivity cannot be ensured at low humidity due to the large dependence. Therefore, a metal oxide is preferable as the conductive layer material. It is preferable to use an uncolored metal oxide as the conductive layer material because the coloring of the entire film is suppressed. As a metal forming a metal oxide without coloring, Zn, Ti, Al, In, Si, Mg, Ba, Mo, W, or V can be mentioned, and a metal oxide containing this as a main component can be used. preferable. Specific examples include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₃ , V ₂ O _5, etc., or composite oxides thereof. In particular, ZnO, TiO ₂ and SnO ₂ are preferable. Examples of the inclusion of heteroatoms include additives such as Al and In for ZnO, addition of Sb, Nb, halogen elements and the like for _{SnO 2} , and Nb and TA for _{TIO 2.} The addition is effective. Furthermore, as described in Japanese Patent Publication No. 59-6235, a material obtained by adhering the above metal oxide to other crystalline metal particles or fibrous substances (for example, titanium oxide) may be used. The volume resistance value and the surface resistance value are different physical property values and cannot be simply compared. However, in order to secure the conductivity of ^10-8 Ω · cm ^{-3 or less in the volume resistance value, the conductivity is required.} It suffices if the layer has ^{a surface resistance value of about 10-10} Ω / □ or less, and more preferably ^10-8 Ω / □.

(2) Liquid Crystal Display Device By using the polarizing plate to which the acrylic resin film according to the present invention is bonded in the liquid crystal display device, various liquid crystal display devices having excellent visibility can be manufactured.

The polarizing plate can be used for liquid crystal display devices of various drive methods such as STN, TN, OCB, HAN, VA (MVA, PVA), IPS, OCB and the like. A VA (MVA, PVA) type liquid crystal display device is preferable.

Normally, two polarizing plates, a polarizing plate on the visual recognition side and a polarizing plate on the backlight side, are used for the liquid crystal display device, but the polarizing plate provided with the acrylic resin film according to the present invention is used as both polarizing plates. It is also preferable to use it as a polarizing plate on one side. In particular, the polarizing plate provided with the acrylic resin film according to the present invention is preferably used as a polarizing plate on the visual side that comes into direct contact with the external environment. In that case, a retardation film such as a cellulose acylate film is arranged on the liquid crystal cell side. Is preferable.

Further, as the polarizing plate on the backlight side, a polarizing plate that does not include the acrylic resin film according to the present invention can also be used. , KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC8UE, KC8UY-HA, KC2UA ), Fujitac T40UZ, Fujitack T60UZ, Fujitack T80UZ, Fujitack TD80UL, Fujitack TD60UL, Fujitack TD40UL, Fujitack R02, Fujitack R06, and above, manufactured by Fuji Film Co., Ltd.) are preferably bonded.

Further, as the polarizing plate on the backlight side, the acrylic resin film according to the present invention is used on the liquid crystal cell side of the polarizing element, and the commercially available cellulose acylate film, polyester film, acrylic film, or polycarbonate film is used on the opposite surface. A bonded polarizing plate can also be preferably used.

By using the polarizing plate, it is possible to obtain a liquid crystal display device having excellent visibility such as display unevenness and front contrast, even if the screen is a large screen liquid crystal display device having a size of 30 inches or more.

(3) Organic electroluminescence display device and element The polarizing plate provided with the acrylic resin film according to the present invention can be preferably used not only for a liquid crystal display device but also for an organic electroluminescence display device. For example, the cyclic polyolefin film of the present invention is stretched in an oblique direction of 45 ° with respect to the above-mentioned transport direction, and is bonded to a polarizing element having an absorption axis in the transport direction by roll-to-roll to achieve circularly polarized light. When a plate is produced and the circularly polarizing plate is used for an organic electroluminescence display device, a display device with high visibility can be obtained.

Further, the acrylic resin film according to the present invention is preferably used as a flexible substrate for an organic electroluminescence element, and in that case, it is preferably applied as a gas barrier film described later.

Regarding specific layer configurations, members, manufacturing methods, etc. of organic EL elements, JP-A-2011-238355, JP-A-2013-077585, JP-A-2013-187090, JP-A-2013-229202, No. Japanese Patent Application Laid-Open No. 2013-232320 and Japanese Patent Application Laid-Open No. 2014-026853 are described in detail and can be referred to.

(4) Gas Barrier Film It is preferable to form a film of an inorganic substance, an organic substance, or a hybrid film of both on the surface of the acrylic resin film according to the present invention, and use the film as a gas barrier film.

Gas barrier properties were measured by the method based on JIS K 7129-1992, the water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)%) is 0.01g ^/ (m 2 · 24h) preferably less it is a film having a gas barrier layer, and further, the oxygen permeability was measured by the method based on JIS K 7126-1987 ^{is, 1 × 10 -3 ml / (} m 2 · 24h · atm) hereinafter, the water vapor permeability is preferably a film having a ^{1 × 10 -5 g / (m} 2 · 24h) or less of the high gas barrier properties.

The method for forming the gas barrier layer applicable to the present invention is not particularly limited, but is, for example, a sputtering method (for example, magnetron cathode sputtering, flat plate magnetron sputtering, 2-pole AC flat plate magnetron sputtering, 2-pole AC rotary magnetron sputtering, etc.). , Vapor deposition method (eg, resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, plasma-assisted vapor deposition, etc.), thermal CVD method, catalytic chemical vapor deposition method (Cat-CVD), capacitive coupling plasma CVD method (CCP-CVD). , Optical CVD method, plasma CVD method (PE-CVD), epitaxial growth method, atomic layer growth method, chemical vapor deposition method such as reactive sputtering method and the like.

Further, the inorganic gas barrier layer may include an organic layer containing an organic polymer. That is, the inorganic gas barrier layer may be a laminate of an inorganic layer containing an inorganic material and an organic layer.

The organic layer is, for example, coated with an organic monomer or oligomer on a resin substrate to form a layer, followed by polymerization and polymerization using, for example, an electron beam device, a UV light source, a discharge device, or other suitable device. It can be formed by cross-linking as needed. It can also be formed, for example, by depositing an organic monomer or an organic oligomer capable of flash evaporation and radiation cross-linking, and then forming a polymer from the organic monomer or the organic oligomer. The coating efficiency can be improved by cooling the resin substrate.

Examples of the method for applying the organic monomer or the organic oligomer include roll coating (for example, gravure roll coating) and spray coating (for example, electrostatic spray coating). In addition, examples of the laminate of the inorganic layer and the organic layer include the laminate described in International Publication No. 2012/003198 and International Publication No. 2011/013341.

In the case of a laminate of an inorganic layer and an organic layer, the thickness of each layer may be the same or different. The layer thickness of the inorganic layer is preferably in the range of 3 to 1000 nm, more preferably in the range of 10 to 300 nm. The layer thickness of the organic layer is preferably in the range of 100 nm to 100 μm, more preferably in the range of 1 to 50 μm.

Further, a method in which a coating liquid containing an inorganic precursor such as polysilazane or tetraethyl orthosilicate (TEOS) is wet-coated on a support and then modified by irradiation with vacuum ultraviolet light to form an inorganic gas barrier layer. The inorganic gas barrier layer is also formed by metal plating on a resin substrate, film metallization technology such as adhering a metal foil and a resin substrate, and the like.

In the case of a laminate of an inorganic layer and an organic layer, the thickness of each layer may be the same or different. The layer thickness of the inorganic layer is preferably in the range of 3 to 1000 nm, more preferably in the range of 10 to 300 nm. The layer thickness of the organic layer is preferably in the range of 100 nm to 100 μm, more preferably in the range of 1 to 50 μm.

Further, a method in which a coating liquid containing an inorganic precursor such as polysilazane or tetraethyl orthosilicate (TEOS) is wet-coated on a support and then modified by irradiation with vacuum ultraviolet light to form an inorganic gas barrier layer. The inorganic gas barrier layer is also formed by metal plating on a resin substrate, film metallization technology such as adhering a metal foil and a resin substrate, and the like.

Hereinafter, an example of the inorganic gas barrier layer formed by using the plasma CVD method will be described.

From the viewpoint of productivity, the inorganic gas barrier layer is preferably formed on the surface of the acrylic resin film according to the present invention by a roll-to-roll method. Further, the apparatus that can be used when manufacturing the inorganic gas barrier layer by such a plasma CVD method is not particularly limited, but includes at least a pair of film forming rollers and a plasma power source, and a pair of formation. It is preferable that the device is configured to be capable of discharging between film rollers. For example, when the manufacturing device shown in FIG. 41 is used, it is manufactured by a roll-to-roll method while using a plasma CVD method. It is also possible to do.

Hereinafter, the method of forming the inorganic gas barrier layer by the plasma CVD method will be described in more detail with reference to FIG. 41. Note that FIG. 41 is a schematic diagram showing an example of a manufacturing apparatus that can be suitably used for manufacturing an inorganic gas barrier layer.

The manufacturing apparatus C31 shown in FIG. 41 includes a delivery roller C32, a transfer roller C33, C34, C35 and C36, a film forming roller C39 and C40, a gas supply tube C41, a plasma generation power supply C42, and a film forming roller. It includes magnetic field generators C43 and C44 installed inside C39 and C40, and a take-up roller C45.

Further, in such a manufacturing apparatus C31, at least the film forming rollers C39 and C40, the gas supply pipe C41, the plasma generation power supply C42, and the magnetic field generators C43 and C44 are arranged in a vacuum chamber (not shown). Has been done.

Further, in such a manufacturing apparatus C31, the vacuum chamber is connected to a vacuum pump (not shown), and the pressure in the vacuum chamber can be appropriately adjusted by the vacuum pump.

In such a manufacturing apparatus C31, each film forming roller is used as a plasma generation power supply C42 so that the pair of film forming rollers (film forming rollers C39 and C40) can function as a pair of counter electrodes. It is connected. Therefore, in such a manufacturing apparatus C31, by supplying electric power by the plasma generation power supply C42, it is possible to discharge the electric power into the space between the film forming roller C39 and the film forming roller C40. Plasma can be generated in the space between the film roller C39 and the film forming roller C40.

When the film forming roller C39 and the film forming roller C40 are also used as electrodes in this way, the materials and designs thereof may be appropriately changed so that they can also be used as electrodes.

Further, in such a manufacturing apparatus C31, it is preferable that the pair of film forming rollers (film forming rollers C39 and C40) are arranged so that their central axes are substantially parallel on the same plane. By arranging a pair of film forming rollers (film forming rollers C39 and C40) in this way, the film forming rate can be doubled.

Then, according to such a manufacturing apparatus C31, it is possible to form the inorganic gas barrier layer C4 (dry gas barrier layer) on the surface of the resin substrate C2 by the CVD method, and the resin substrate is formed on the film forming roller C39. While the inorganic gas barrier layer component can be deposited on the surface of C2, the inorganic gas barrier layer component can also be deposited on the surface of the resin substrate C2 on the film forming roller C40, so that the inorganic gas barrier layer component can be deposited on the surface of the resin substrate C2. The inorganic gas barrier layer C4 can be efficiently formed.

Inside the film forming rollers C39 and C40, magnetic field generators C43 and C44 fixed so as not to rotate even if the film forming roller rotates are provided, respectively.

The magnetic field generators C43 and C44 provided on the film forming rollers C39 and C40 are the magnetic field generators C43 provided on one of the film forming rollers C39 and the magnetic field generators C44 provided on the other film forming roller C40. It is preferable to arrange the magnetic poles so that the magnetic field lines do not straddle between them and the respective magnetic field generators C43 and C44 form a substantially closed magnetic circuit. By providing such magnetic field generators C43 and C44, it is possible to promote the formation of a magnetic field in which magnetic field lines swell near the opposite surfaces of the film forming rollers C39 and C40, and plasma is converged on the bulging portion. Since it becomes easy, it is excellent in that the film forming efficiency can be improved.

Further, the magnetic field generators C43 and C44 provided on the film forming rollers C39 and C40 each have a racetrack-shaped magnetic pole long in the roller axial direction, and the magnetic field generator C43 on one side and the magnetic field generator C44 on the other side are different from each other. It is preferable to arrange the magnetic poles so that the magnetic poles facing each other have the same polarity. By providing such magnetic field generators C43 and C44, the magnetic field generators C43 and C44 face each other along the length direction of the roller shaft without straddling the magnetic field generators on the roller side where the magnetic field lines face each other. A racetrack-like magnetic field can be easily formed near the roller surface facing the (discharge region), and the plasma can be converged on the magnetic field, so that a wide resin wound along the roller width direction is used. It is excellent in that the inorganic gas barrier layer C4, which is a vapor deposition film, can be efficiently formed by using the substrate C2.

As the film forming rollers C39 and C40, known rollers can be used as appropriate. As such film forming rollers C39 and C40, it is preferable to use those having the same diameter from the viewpoint of being able to form a thin film more efficiently.

Further, the diameters of the film forming rollers C39 and C40 are preferably in the range of 300 to 1000 mmφ, particularly in the range of 300 to 700 mmφ, from the viewpoint of discharge conditions, chamber space and the like. When the diameter of the film forming roller is 300 mmφ or more, the plasma discharge space does not become small, so that the productivity does not deteriorate and the total heat of the plasma discharge can be avoided from being applied to the resin substrate C2 in a short time. It is preferable because the damage to the substrate C2 can be reduced. On the other hand, when the diameter of the film forming roller is 1000 mmφ or less, it is preferable because the practicality can be maintained in terms of device design including the uniformity of the plasma discharge space.

In such a manufacturing apparatus C31, the resin substrate C2 is arranged on a pair of film forming rollers (deposition rollers C39 and C40) so that the surfaces of the resin substrate C2 face each other. By arranging the resin substrate C2 in this way, the resin existing between the pair of film forming rollers when discharging is performed in the facing space between the film forming roller C39 and the film forming roller C40 to generate plasma. It is possible to form a film on each surface of the substrate C2 at the same time.

That is, according to such a manufacturing apparatus C31, the inorganic gas barrier layer component is deposited on the surface of the resin substrate C2 on the film forming roller C39 by the plasma CVD method, and the inorganic gas is further deposited on the film forming roller C40. Since the barrier layer component can be deposited, the inorganic gas barrier layer C4 can be efficiently formed on the surface of the resin substrate C2.

As the delivery roller C32 and the transfer rollers C33 to C36 used in such a manufacturing apparatus C31, known rollers can be appropriately used. Further, the winding roller C45 may be any as long as it can wind the sealing substrate C1 having the inorganic gas barrier layer C4 formed on the resin substrate C2, and is not particularly limited, and a known roller is appropriately used. be able to.

Further, as the gas supply pipe C41 and the vacuum pump (not shown), those capable of supplying or discharging the raw material gas or the like at a predetermined speed can be appropriately used.

Further, the gas supply pipe C41 which is a gas supply means is preferably provided in one of the facing spaces (discharge region; film formation zone) between the film forming roller C39 and the film forming roller C40, and is a vacuum exhausting means. The pump is preferably provided on the other side of the facing space. By arranging the gas supply pipe C41 as the gas supply means and the vacuum pump as the vacuum exhaust means in this way, the film-forming gas is efficiently supplied to the facing space between the film-forming roller C39 and the film-forming roller C40. It is excellent in that it can improve the film forming efficiency.

Further, as the plasma generation power supply C42, a known power source of a plasma generation device can be used as appropriate. Such a plasma generation power supply C42 supplies electric power to the film forming roller C39 and the film forming roller C40 connected to the power forming roller C42, and makes it possible to use these as counter electrodes for discharging. As such a power source C42 for plasma generation, since plasma CVD can be carried out more efficiently, a power source C42 capable of alternately reversing the polarities of a pair of film forming rollers (such as an AC power supply) is used. It is preferable to use it.

Further, since the plasma generation power supply C42 can carry out plasma CVD more efficiently, the applied power can be within the range of 100 W to 10 kW, and the AC frequency can be set to 50 Hz. It is more preferable that the frequency can be set to ~ 500 kHz.

Further, as the magnetic field generators C43 and C44, known magnetic field generators can be appropriately used. Further, as the resin substrate C2, in addition to the resin substrate used in the present invention, a resin substrate C4 having an inorganic gas barrier layer C4 formed in advance can be used. As described above, it is possible to increase the thickness of the inorganic gas barrier layer C4 by using the resin substrate C2 on which the inorganic gas barrier layer C4 is formed in advance.

Using the manufacturing apparatus C31 shown in FIG. 41, for example, the type of raw material gas, the power of the electrode drum of the plasma generator, the pressure in the vacuum chamber, the diameters of the film forming rollers C39 and C40, and the resin substrate C2. The inorganic gas barrier layer C4 can be manufactured by appropriately adjusting the transport speed.

That is, the film forming gas (raw material gas or the like) is supplied into the vacuum chamber by using the manufacturing apparatus C31 shown in FIG. 41, and a discharge is generated between the pair of film forming rollers C39 and C40. (Raw material gas, etc.) is decomposed by plasma, and an inorganic gas barrier layer C4 is formed on the surface of the resin substrate C2 on the film forming roller C39 and on the surface of the resin substrate C2 on the film forming roller C40 by the plasma CVD method. NS. At this time, a racetrack-shaped magnetic field is formed near the roller surface facing the facing space (discharge region) along the length direction of the roller shafts of the film forming rollers C39 and C40, and the plasma is converged on the magnetic field. In such a film formation, the resin substrate C2 is conveyed by a delivery roller C32, a film forming roller C39, or the like, thereby enabling a continuous roll-to-roll film forming process of the resin substrate C2. An inorganic gas barrier layer C4 is formed on the surface.

As the film-forming gas (raw material gas or the like) supplied from the gas supply pipe C41 to the facing space, a raw material gas, a reaction gas, a carrier gas, and a discharge gas can be used alone or in combination of two or more. The raw material gas in the film-forming gas used for forming the inorganic gas barrier layer C4 can be appropriately selected and used according to the material of the inorganic gas barrier layer C4 to be formed.

As such a raw material gas, for example, an organosilicon compound containing silicon or an organic compound gas containing carbon can be used. Examples of such an organic silicon compound include hexamethyldisiloxane (HMDSO), hexamethyldisilane (HMDS), 1,1,3,3-tetramethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, and hexamethyldisilane. , Methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane (TMS), tetraethoxysilane (TEOS), phenyltrimethoxysilane, methyltriethoxy Examples thereof include silane and octamethylcyclotetrasiloxane. Among these organosilicon compounds, hexamethyldisiloxane and 1,1,3,3-tetramethyldisiloxane are preferable from the viewpoint of the handleability of the compound and the gas barrier property of the obtained inorganic gas barrier layer C4. .. These organosilicon compounds can be used alone or in combination of two or more. Examples of the carbon-containing organic compound gas include methane, ethane, ethylene, and acetylene. As the organosilicon compound gas and the organosilicon compound gas, an appropriate raw material gas is selected according to the type of the inorganic gas barrier layer C4.

Further, as the film forming gas, a reaction gas may be used in addition to the raw material gas. As such a reaction gas, a gas that reacts with the raw material gas to become an inorganic compound such as an oxide or a nitride can be appropriately selected and used. As the reaction gas for forming the oxide, for example, oxygen or ozone can be used. Further, as the reaction gas for forming the nitride, for example, nitrogen or ammonia can be used. These reaction gases can be used alone or in combination of two or more, for example, in the case of forming an oxynitride, in order to form a nitride with the reaction gas for forming an oxide. Can be used in combination with the reaction gas of.

As the film-forming gas, a carrier gas may be used, if necessary, in order to supply the raw material gas into the vacuum chamber. Further, as the film-forming gas, a discharge gas may be used, if necessary, in order to generate a plasma discharge. As such a carrier gas and a gas for discharge, known ones can be used as appropriate, and for example, a rare gas such as helium, argon, neon, or xenon or hydrogen can be used.

When such a film-forming gas contains a raw material gas and a reaction gas, the ratio of the raw material gas to the reaction gas is theoretically necessary for the raw material gas and the reaction gas to completely react with each other. It is preferable not to make the ratio of the reaction gas too excessive, rather than the ratio of the amount of gas. It is excellent in that excellent gas barrier properties and bending resistance can be obtained by the formed inorganic gas barrier layer C4 by not making the ratio of the reaction gas excessive. When the film-forming gas contains an organosilicon compound and oxygen, it is preferably not more than the theoretical oxygen amount required to completely oxidize the entire amount of the organosilicon compound in the film-forming gas.

Hereinafter, in the production of the inorganic gas barrier layer C4 using the apparatus of FIG. 41, hexamethyldisiloxane (organosilicon compound, HMDSO, (CH ₃ ) ₆ Si ₂ O) as a raw material gas was used as the film forming gas. Taking as an _{example the case of producing a silicon-oxygen-based thin film using a reaction gas containing oxygen (O 2} ), a suitable ratio of the raw material gas and the reaction gas in the film-forming gas is obtained. , Will be explained in more detail.

A film-forming gas containing hexamethyldisiloxane (HMDSO, (CH ₃ ) ₆ Si _{2 O) as a raw material gas and oxygen (O 2} ) as a reaction gas is reacted by plasma CVD to form a silicon-oxygen system. When the thin film of No. 1 is produced, the reaction represented by the following reaction formula (1) occurs depending on the film-forming gas, and silicon dioxide is produced.

Reaction equation (1)
(CH ₃ ) ₆ Si ₂ O + 12O ₂ → 6CO ₂ + 9H ₂ O + _{2SiO 2}
In such a reaction, the amount of oxygen required to completely oxidize 1 mol of hexamethyldisiloxane is 12 mol. Therefore, when 12 mol or more of oxygen is contained in 1 mol of hexamethyldisiloxane in the film-forming gas and the reaction is completed, a uniform silicon dioxide film is formed.

Therefore, in the present invention, when forming the inorganic gas barrier layer, the amount of oxygen is chemically applied to 1 mol of hexamethyldisiloxane so that the reaction of the above reaction formula (1) does not completely proceed. It is preferably less than 12 mol of the ratio.

In the actual reaction in the plasma CVD chamber, the raw material hexamethyldisiloxane and the oxygen of the reaction gas are supplied from the gas supply unit to the film forming region to form a film, so that the molar amount of oxygen in the reaction gas is formed. Even if the (flow rate) is 12 times the molar amount (flow rate) of the raw material hexamethyldisiloxane, the reaction cannot actually proceed completely, and the oxygen content is increased. It is considered that the reaction is completed only when a large excess is supplied compared to the chemical quantity theory ratio (for example, in order to obtain silicon oxide by complete oxidation by CVD, the molar amount (flow rate) of oxygen is used as the raw material hexamethyldi. It may be about 20 times or more the molar amount (flow rate) of siloxane).

Therefore, the molar amount (flow rate) of oxygen with respect to the molar amount (flow rate) of hexamethyldisiloxane as a raw material is preferably 12 times or less (more preferably 10 times or less) the stoichiometric ratio. .. By containing hexamethyldisiloxane and oxygen in such a ratio, carbon atoms and hydrogen atoms in hexamethyldisiloxane that have not been completely oxidized are incorporated into the inorganic gas barrier layer, and the resulting encapsulation substrate is used. It is possible to exhibit excellent gas barrier properties and bending resistance.

From the viewpoint of use in a flexible substrate for devices that require transparency such as organic EL elements and solar cells, the molar amount of oxygen with respect to the molar amount (flow rate) of hexamethyldisiloxane in the film-forming gas. The lower limit of (flow rate) is preferably more than 0.1 times the molar amount (flow rate) of hexamethyldisiloxane, and more preferably more than 0.5 times.

The pressure (degree of vacuum) in the vacuum chamber can be appropriately adjusted according to the type of raw material gas and the like, but is preferably in the range of 0.5 to 50 Pa.

Further, in such a plasma CVD method, in order to discharge between the film forming roller C39 and the film forming roller C40, the electrode drums (installed on the film forming rollers C39 and C40) connected to the plasma generation power supply C42 are installed. The power applied to) can be appropriately adjusted according to the type of raw material gas, the pressure in the vacuum chamber, etc., and cannot be unconditionally stated, but it should be within the range of 0.1 to 10 kW. Is preferable. If the applied power is 0.1 kW or more, the generation of particles can be sufficiently suppressed, while if the applied power is 10 kW or less, the amount of heat generated during film formation can be suppressed, and the generation of particles can be suppressed. It is possible to suppress the temperature rise of the surface of the resin substrate. Therefore, it is excellent in that the resin substrate does not lose heat and wrinkles can be prevented from being generated during film formation.

The transport speed (line speed) of the resin substrate C2 can be appropriately adjusted according to the type of raw material gas, the pressure in the vacuum chamber, and the like, but is preferably in the range of 0.25 to 100 m / min. It is more preferably in the range of 0.5 to 20 m / min. When the line speed is 0.25 m / min or more, it is possible to effectively suppress the generation of wrinkles due to heat on the resin substrate. On the other hand, if it is 100 m / min or less, it is excellent in that a sufficient layer thickness can be secured as an inorganic gas barrier layer without impairing productivity.

As described above, as a more preferable embodiment of the present embodiment, the inorganic gas barrier layer used in the present invention is plasma using a plasma CVD apparatus (roll-to-roll method) having an opposed roller electrode shown in FIG. 41. The film is formed by the CVD method. This is excellent in flexibility (flexibility) when mass-produced using a plasma CVD device (roll-to-roll method) having opposed roller electrodes, and transports mechanical strength, especially roll-to-roll. This is because it is possible to efficiently manufacture an inorganic gas barrier layer that has both durability and gas barrier performance. Such a manufacturing apparatus is also excellent in that it is possible to easily mass-produce a sealed substrate used for a solar cell, an electronic component, or the like, which is required to have durability against a temperature change, at a low cost.

Next, the inorganic gas barrier layer formed by reforming the layer containing polysilazane will be described in detail.

The polysilazane used for forming the inorganic gas barrier layer used in the present invention is a polymer having a silicon-nitrogen bond, and has a bond of Si—N, Si—H, N—H, etc. SiO ₂ , Si ₃ N. _4, and it is both ceramic precursor inorganic polymer such as an intermediate solid solution SiO _x N _y, preferably has a structure represented by the following general formula (P).

General formula (P)
-[-Si (R ₁ ) (R ₂ ) -N (R ₃ )-] _n-
In the general formula (P), R ₁ , R ₂ and R ₃ independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group and an alkoxy group, respectively. R ₁ , R ₂ and R ₃ may be the same or different from each other.

Further, in the above general formula (P), n is an integer, and it is preferable that polysilazane having a structure represented by the general formula (P) is defined to have a number average molecular weight of 150 to 150,000 g / mol.

In the present invention, perhydropolysilazane (PHPS) in which all of _{R 1} , R ₂ and R ₃ are hydrogen atoms is particularly preferable from the viewpoint of the denseness of the obtained inorganic gas barrier layer as a film.

Perhydropolysilazane is presumed to have a linear structure and a ring structure centered on 6- and 8-membered rings. Its molecular weight is about 600 to 2000 (in terms of polystyrene) in terms of number average molecular weight (Mn), is a liquid or solid substance, and varies depending on the molecular weight.

Polysilazane is commercially available in a solution state in which it is dissolved in an organic solvent, and the commercially available product can be used as it is as a coating liquid for forming a polysilazane layer. Commercially available products of polysilazane solution include NN120-10, NN120-20, NAX120-20, NN110, NN310, NN320, NL110A, NL120A, NL120-20, NL150A, NP110, NP140, SP140 manufactured by AZ Electronic Materials Co., Ltd. Can be mentioned.

The solvent for preparing a coating liquid containing polysilazane (hereinafter, also simply referred to as a coating liquid containing polysilazane) is not particularly limited as long as it can dissolve polysilazane, but water that easily reacts with polysilazane and water and An organic solvent that does not contain a reactive group (for example, a hydroxy group or an amine group) and is inert to polysilazane is preferable, and an aprotonic organic solvent is more preferable.

Specifically, as the solvent for preparing the polysilazane-containing coating liquid, an aproton solvent, for example, an aliphatic hydrocarbon such as pentane, hexane, cyclohexane, toluene, xylene, sorbesso, and terben, and an alicyclic hydrocarbon , Hydrocarbon solvents such as aromatic hydrocarbons, halogen hydrocarbon solvents such as methylene chloride and trichloroethane, esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, and aliphatic solvents such as dibutyl ether, dioxane and tetrahydrofuran. Examples thereof include ethers such as ethers and alicyclic ethers (for example, tetrahydrofuran, dibutyl ether, mono- and polyalkylene glycol dialkyl ethers (diglymes)). The solvent is selected according to the purpose such as the solubility of polysilazane and the evaporation rate of the solvent, and may be used alone or in the form of a mixture of two or more kinds.

The concentration of polysilazane in the polysilazane-containing coating liquid is not particularly limited and varies depending on the layer thickness of the target inorganic gas barrier layer and the pot life of the coating liquid, but is preferably in the range of 0.1 to 30% by mass. It is preferably in the range of 0.5 to 20% by mass, more preferably in the range of 1 to 15% by mass.

The polysilazane-containing coating liquid preferably contains a catalyst together with polysilazane in order to promote the modification to silicon nitride. As the catalyst applicable to the present invention, a basic catalyst is preferable, and in particular, N, N-diethylethanolamine, N, N-dimethylethanolamine, triethanolamine, triethylamine, 3-morpholinopropylamine, N, N, Amine catalysts such as N', N'-tetramethyl-1,3-diaminopropane, N, N, N', N'-tetramethyl-1,6-diaminohexane, Pt compounds such as Pt acetylacetonate, propion Examples thereof include Pd compounds such as acid Pd, metal catalysts such as Rh compounds such as Rh acetylacetonate, and N-heterocyclic compounds. Of these, it is preferable to use an amine catalyst. The concentration of the catalyst to be added at this time is preferably in the range of 0.1 to 10% by mass, more preferably in the range of 0.2 to 5% by mass, and further preferably in the range of 0.5, based on polysilazane. It is in the range of ~ 2% by mass. By setting the amount of the catalyst added within this range, it is possible to avoid excessive silanol formation due to the rapid progress of the reaction, a decrease in the film density, an increase in film defects, and the like.

The additives listed below can be used in the polysilazane-containing coating liquid, if necessary. For example, cellulose ethers, cellulose esters (eg, ethyl cellulose, nitrocellulose, cellulose acetate, cellulose acetobutyrate, etc.), natural resins (eg, rubber, rosin resin, etc.), synthetic resins (eg, polymer resins, etc.), condensation. Resin (for example, aminoplast, particularly urea resin, melamine cellulose resin, alkyd resin, acrylic resin, polyester or modified polyester, epoxide, polyisocyanate or blocked polyisocyanate, polysiloxane, etc.).

As a method for applying the polysilazane-containing coating liquid, a conventionally known appropriate wet coating method is adopted. Specific examples include a spin coating method, a die coating method, a roll coating method, a flow coating method, an inkjet method, a spray coating method, a printing method, a dip coating method, a cast film forming method, a bar coating method, a gravure printing method, and the like. Be done.

The coating thickness can be appropriately set according to the purpose. For example, the coating thickness after drying is preferably about 10 nm to 10 μm, more preferably in the range of 15 nm to 1 μm, and further preferably in the range of 20 to 500 nm. If the layer thickness of the polysilazane layer is 10 nm or more, sufficient gas barrier properties can be obtained, and if it is 10 μm or less, stable coatability can be obtained when the polysilazane layer is formed, and high light transmittance can be realized. ..

The reforming treatment refers to a reaction in which a part or all of a polysilazane compound is converted to silicon oxide or silicon nitride.

As a result, it is possible to form an inorganic thin film having a level that can contribute to the gas barrier property (water vapor transmission rate of 1 × 10 ^-3 g / (m ^{2 · day) or less) as a whole of the inorganic gas barrier layer.}

Specific examples thereof include heat treatment, plasma treatment, and active energy ray irradiation treatment. Above all, the treatment by irradiation with active energy rays is preferable from the viewpoint that it can be modified at a low temperature and the degree of freedom in selecting the base material type is high.

(Heat treatment)
Examples of the heat treatment method include a method of contacting a substrate with a heating element such as a heat block to heat the coating film by heat conduction, a method of heating the environment in which the coating film is placed by an external heater using a resistance wire or the like, and a method of heating the coating film. Examples thereof include a method using light in the infrared region such as an IR heater, but the method is not limited thereto. When heat treatment is performed, a method capable of maintaining the smoothness of the coating film may be appropriately selected.

The temperature for heating the coating film is preferably in the range of 40 to 250 ° C, more preferably in the range of 60 to 150 ° C. The heating time is preferably in the range of 10 seconds to 100 hours, preferably in the range of 30 seconds to 5 minutes.

(Plasma processing)
In the present invention, as the plasma treatment that can be used as the reforming treatment, a known method can be used, and atmospheric pressure plasma treatment and the like can be preferably mentioned. Compared to the plasma CVD method under vacuum, the atmospheric pressure plasma CVD method, which performs plasma CVD processing in the vicinity of atmospheric pressure, not only requires no decompression and is highly productive, but also has a high plasma density, resulting in film formation. In the high pressure condition of high pressure and under atmospheric pressure as compared with the condition of the usual CVD method, the average free step of the gas is very short, so that a very homogeneous film can be obtained.

In the case of atmospheric pressure plasma treatment, nitrogen gas or Group 18 atom of the long periodic table, specifically, helium, neon, argon, krypton, xenon, radon and the like is used as the discharge gas. Of these, nitrogen, helium, and argon are preferably used, and nitrogen is particularly preferable because of its low cost.

(Active energy ray irradiation treatment)
As the active energy rays, for example, infrared rays, visible rays, ultraviolet rays, X-rays, electron rays, α rays, β rays, γ rays and the like can be used, but electron beams or ultraviolet rays are preferable, and ultraviolet rays are more preferable. Ozone and active oxygen atoms generated by ultraviolet rays (synonymous with ultraviolet light) have high oxidizing ability, and can form a gas barrier layer having high density and insulating properties at low temperatures.

In the ultraviolet irradiation treatment, any commonly used ultraviolet generator can be used.

In the method for producing an inorganic gas barrier layer used in the present invention, a coating film containing a polysilazane compound from which water has been removed is modified by treatment with ultraviolet light irradiation. Ozone and active oxygen atoms generated by ultraviolet rays have high oxidizing ability, and can form a silicon oxide film or a silicon nitride film having high density and insulating properties at low temperature.

By this ultraviolet light irradiation, O ₂ and H ₂ O that contribute to ceramicization, an ultraviolet absorber, and polysilazane itself are excited and activated. Then, the excited polysilazane is promoted to be ceramicized, and the obtained ceramic film becomes dense. Ultraviolet light irradiation is effective at any time after the coating film is formed.

Any commonly used ultraviolet light generator can be used for the vacuum ultraviolet light irradiation treatment in the present invention. The ultraviolet light referred to in the present invention generally refers to ultraviolet light including an electromagnetic wave having a wavelength of 10 to 200 nm, which is called vacuum ultraviolet light.

For irradiation with vacuum ultraviolet light, it is preferable to set the irradiation intensity and irradiation time within a range in which the resin substrate supporting the layer containing the polysilazane compound before modification to be irradiated is not damaged.

For example, using a 2 kW (80 W / cm × 25 cm) lamp, the base material-ultraviolet rays so that ^{the strength of the base material surface is in the range of 20} to 300 mW / cm 2, preferably in the range of 50 to 200 mW / cm ^2. The distance between the irradiation lamps can be set, and irradiation can be performed for 0.1 seconds to 10 minutes.

Generally, when the temperature of the support during the ultraviolet irradiation treatment becomes 150 ° C. or higher, in the case of a resin film or the like, the characteristics of the support are impaired, such as deformation of the support and deterioration of its strength. Become. However, in the case of a film having high heat resistance such as acrylic resin, the modification treatment at a higher temperature is possible. Therefore, there is no general upper limit to the temperature of the support at the time of irradiation with ultraviolet rays, and a person skilled in the art can appropriately set the temperature depending on the type of the resin substrate. Further, the atmosphere of ultraviolet irradiation is not particularly limited, and it may be carried out in the air.

Examples of the means for generating such ultraviolet rays include, but are not limited to, metal halide lamps, high-pressure mercury lamps, low-pressure mercury lamps, xenon arc lamps, carbon arc lamps, excimer lamps, UV light lasers, and the like. In addition, when irradiating the generated ultraviolet rays to the polysilazane layer before modification, from the viewpoint of improving efficiency and achieving uniform irradiation, the ultraviolet rays from the source are reflected by the reflector and then the polysilazane before modification. It is desirable to irradiate the layer.

Ultraviolet irradiation can be applied to both batch processing and continuous processing, and can be appropriately selected depending on the shape of the resin substrate to be used. When the resin substrate having the coating layer containing the polysilazane compound is in the form of a long film, it is made into ceramics by continuously irradiating the resin substrate with ultraviolet rays in a drying zone equipped with an ultraviolet ray generation source as described above while transporting the resin substrate. can do. The time required for ultraviolet irradiation varies depending on the composition and concentration of the resin substrate to be used and the coating layer containing the polysilazane compound, but is generally 0.1 seconds to 10 minutes, preferably 0.5 seconds to 3 minutes.

(Vacuum UV irradiation treatment: Excimer irradiation treatment)
In the present invention, the most preferable modification treatment method is treatment by vacuum ultraviolet irradiation (excimer irradiation treatment).

When irradiating with vacuum ultraviolet light (VUV), it is preferable to use a dry inert gas as a gas other than these oxygens, and it is particularly preferable to use a dry nitrogen gas from the viewpoint of cost. The oxygen concentration can be adjusted by measuring the flow rates of the oxygen gas and the inert gas introduced into the irradiation chamber and changing the flow rate ratio.

Specifically, the method for modifying a layer containing a polysilazane compound before modification in the present invention is a treatment by irradiation with vacuum ultraviolet light. The treatment by vacuum ultraviolet light irradiation uses light energy of 100 to 200 nm, which is larger than the interatomic bonding force in the polysilazane compound, preferably light energy of a wavelength of 100 to 180 nm, and the atomic bonding is a photon called a photon process. It is a method of forming a silicon oxide film at a relatively low temperature by advancing an oxidation reaction with active oxygen or ozone while directly cutting by the action of only light. A noble gas excimer lamp is preferably used as the vacuum ultraviolet light source required for this purpose.

Since the atoms of rare gases such as Xe, Kr, Ar, and Ne are chemically bonded and do not form molecules, they are called inert gases. However, a rare gas atom (excited atom) that has obtained energy by electric discharge or the like can be combined with another atom to form a molecule. If the noble gas is xenon
e + Xe → e + Xe ^*
Xe ^* + Xe + Xe → Xe ₂ ^* + Xe
Xe ₂ ^* → Xe + Xe + hν (172nm)
Then, when the excited excimer molecule Xe ₂ ^* transitions to the ground state, it emits 172 nm excimer light (vacuum ultraviolet light).

One of the characteristics of excimer lamps is that they are highly efficient because the radiation is concentrated on one wavelength and almost no light other than the required light is emitted. In addition, since extra light is not emitted, the temperature of the object can be kept low. Furthermore, since it does not take time to start and restart, it is possible to turn on and blink instantly.

In vacuum ultraviolet irradiation step, preferably the illumination of the vacuum ultraviolet rays in the coated surface to receive the coating film containing a polysilazane compound is in the range of ^{1mW / cm 2 ~10W / cm 2} , in the range of 30~200mW / cm ² It is more preferable that it is in ^{the range of 50 to 160 mW / cm 2} , and it is further preferable that it is in the range of 50 to 160 mW / cm 2. If it is 1 mW / cm ² or more, sufficient reforming efficiency can be obtained. Further, when it is 10 W / cm ² or less, ablation of the coating film is unlikely to occur and damage to the resin substrate is unlikely to occur.

Irradiation energy amount of the VUV in the layer containing a polysilazane compound is preferably in the range of 10 to 10000 mJ / cm ^2, more preferably in the range of 100~8000mJ / cm ^2, it is 200~6000mJ / cm ² It is more preferable, and it is particularly preferable that it is in the range of ^{500 to 5000 mJ / cm 2.} If 10 mJ / cm ² or more sufficient reforming efficiency is obtained, 10000 mJ / cm ² or less value, if cracks and the resin substrate thermal deformation hardly occurs in.

Further, the oxygen concentration when irradiating with vacuum ultraviolet light (VUV) is preferably in the range of 300 to 10000 volume ppm (1% by volume), more preferably 500 to 5000 volume ppm. By adjusting within such an oxygen concentration range, it is possible to prevent the formation of an inorganic gas barrier layer having an excess of oxygen and prevent deterioration of the gas barrier property.

A method using a dielectric barrier discharge is known to obtain excimer light emission. Dielectric barrier discharge is a method of lightning generated in the gas space by arranging a gas space between both electrodes via a dielectric (transparent quartz in the case of excimer lamps) and applying a high-frequency high voltage of several tens of kHz to the electrodes. A similar, very thin discharge called a microdischarge.

Further, as a method for efficiently obtaining excimer light emission, an electrodeless electric field discharge is also known in addition to the dielectric barrier discharge. Electrodeless electric field discharge is discharge due to capacitive coupling, and is also known as RF discharge. The lamp, the electrodes, and their arrangement may be basically the same as the dielectric barrier discharge, but the high frequency applied between the two electrodes is lit at several MHz. As for the electrodeless electric field discharge, a uniform discharge can be obtained spatially and temporally in this way.

The Xe excimer lamp is excellent in luminous efficiency because it emits ultraviolet rays having a short wavelength of 172 nm at a single wavelength. Since this light has a large oxygen absorption coefficient, it is possible to generate radical oxygen atom species and ozone at a high concentration with a small amount of oxygen. It is also known that the energy of light having a short wavelength of 172 nm that dissociates the bonds of organic substances has high capacity. With the high energy of active oxygen, ozone and ultraviolet radiation, it is possible to modify the coating layer containing the polysilazane compound in a short time. Therefore, compared to low-pressure mercury lamps and plasma cleaning with wavelengths of 185 nm and 254 nm, the process time is shortened due to high throughput, the equipment area is reduced, and irradiation of organic materials, plastic substrates, resin films, etc. that are susceptible to heat damage is performed. It is possible.

Moreover, since the excimer lamp has a high light generation efficiency, it can be turned on with a low power input. Further, since light having a long wavelength that causes a temperature rise due to light is not emitted and energy of a single wavelength is irradiated in the ultraviolet region, the surface temperature of the object to be irradiated is suppressed from rising. Therefore, it is suitable for irradiating a sealed substrate using a resin film such as polyethylene terephthalate, which is said to be easily affected by heat, as a base material.

Layer formed by the above coating, the step of irradiating vacuum ultraviolet rays on a coating film containing a polysilazane compound, at least a part of the polysilazane is modified, the composition of the SiO _x N _y C _z overall layer A silicon-containing film containing the indicated silicon nitride is formed.

The membrane composition can be measured by measuring the atomic composition ratio using an XPS (X-ray Photoelectron Spectroscopy) surface analyzer. It can also be measured by cutting the silicone-containing film and measuring the atomic composition ratio of the cut surface with an XPS surface analyzer.

Further, the film density can be appropriately set according to the purpose. For example, the film density of the silicone-containing film is preferably in the range of ^{1.5 to 2.6 g / cm 3.} Within this range, the denseness of the film is improved, and deterioration of the gas barrier property and deterioration of the film under high temperature and high humidity conditions can be prevented.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Although the display of "parts" or "%" is used in the examples, it represents "parts by mass" or "% by mass" unless otherwise specified.

[Example 1]
<Preparation of rubber particles B-1>
38.2 liters of ion-exchanged water and 111.6 g of sodium dioctyl sulfosuccinate were put into a reactor with a reflux condenser having an internal volume of 60 liters, and the temperature was raised to 75 ° C. under a nitrogen atmosphere while stirring at a rotation speed of 250 rpm. , The effect of oxygen was virtually eliminated. A monomer mixture (c1) consisting of 1657 g of methyl methacrylate (MMA), 21.6 g of butyl acrylate (BA), and 1.68 g of allyl methacrylate (ALMA) after adding 0.36 g of ammonium persulfate (APS) and stirring for 5 minutes. ) Was added all at once and held for another 20 minutes after the detection of the exothermic peak to complete the polymerization of the innermost hard layer.

Next, 3.48 g of ammonium persulfate (APS) was added, and after stirring for 5 minutes, a monomer mixture consisting of 1961 g of butyl acrylate (BA), 346 g of methyl methacrylate (MMA), and 264.0 g of allyl methacrylate (ALMA) (ALMA). a1) (BA / MMA = 85/15 mass ratio) was continuously added over 120 minutes and held for another 120 minutes after the addition was completed to complete the polymerization of the soft layer.

Next, 1.32 g of ammonium persulfate (APS) was added, and after stirring for 5 minutes, a monomer mixture (b1) consisting of 2106 g of methyl methacrylate (MMA) and 201.6 g of butyl acrylate (BA) was continuously added over 20 minutes. And held for another 20 minutes after the addition was completed to complete the polymerization of the hard layer 1.

Then, 1.32 g of ammonium persulfate (APS) is added, and after 5 minutes, it consists of 3148 g of methyl methacrylate (MMA), 201.6 g of butyl acrylate (BA), and 10.1 g of n-octyl mercaptan (n-OM). The monomer mixture (b2) was added continuously over 20 minutes and held for another 20 minutes after the addition was complete. Then, the temperature was raised to 95 ° C. and held for 60 minutes to complete the polymerization of the hard layer 2.

A small amount of the obtained polymer latex was collected, and the flat particle size was determined by an absorptiometry. As a result, it was 0.10 μm. The remaining latex is put into a warm aqueous solution of 3% by mass sodium sulfate, salted out and solidified, then dehydrated and washed repeatedly, and then dried to obtain acrylic particles having a four-layer structure (rubber particles B-1). Got The average particle size of the obtained rubber particles B-1 was 200 nm, and the glass transition temperature (Tg) was −30 ° C.

<Manufacturing of optical film 101>
(Preparation of rubber particle dispersion)
22.6 parts by mass of rubber particles B-1 and 400 parts by mass of methylene chloride are stirred and mixed with a dissolver for 50 minutes, and then dispersed under 1500 rpm conditions using a milder disperser (manufactured by Pacific Machinery & Engineering Co., Ltd.). Then, a rubber particle dispersion was obtained. Then, the rubber particle dispersion was stagnated in the storage tank for 6 hours, and was constantly stirred during storage.

(Preparation of doping)
Then, a dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressurized dissolution tank. Next, the acrylic resin (A-1) shown in Table II below was charged into the pressurized dissolution tank with stirring. Then, the rubber particle dispersion liquid prepared above was added, and the mixture was heated to 60 ° C. and completely dissolved while stirring. The heating temperature was raised from room temperature at 5 ° C./min, dissolved in 30 minutes, and then lowered at 3 ° C./min. The obtained solution was filtered through a filter having a filtration accuracy of 30 μm, and then a dope was obtained.

(Composition of dope)
Acrylic resin (A-1): 88 parts by mass Methylene chloride: 70 parts by mass Ethanol: 50 parts by mass Rubber particle dispersion: 400 parts by mass

(Film formation)
Then, using an endless belt spreading device, the dope was uniformly cast on the stainless belt support at a temperature of 31 ° C. and a width of 1800 mm. The temperature of the stainless steel belt was controlled to 28 ° C. The transport speed of the stainless steel belt was set to 20 m / min.

On the stainless belt support, the solvent was evaporated until the amount of residual solvent in the cast film was 30%. Then, it was peeled off from the stainless belt support at a peeling tension of 128 N / m. While the peeled film was conveyed by a large number of rollers, the obtained film-like material was stretched 1.2 times in the width direction under the condition of (Tg + 10) ° C. (120 ° C. in this example) with a tenter. Then, the film was further dried while being conveyed by a roll, and the end portion sandwiched between the tenter clips was slit by a laser cutter and wound up to obtain an optical film 101 having a film thickness of 40 μm.

<Manufacturing of optical films 102 to 112>
Optical films 102 to 112 were produced in the same manner as in the method for producing the optical film 101, except that the conditions shown in Table II and Table III were changed.

<Evaluation of optical film>
The following measurements and evaluations were performed on the optical films 101 to 112.
<Transparent mapping>
The measurement was performed using the image quality measuring device ICM-1T manufactured by Suga Test Instruments Co., Ltd. The transmission measurement, which is usually carried out at an incident angle of 0 degrees, was carried out as a transmission measurement at which the incident angle was intentionally set to 75 degrees. The sample was set so that the flow direction of the film and the direction of the optical comb teeth were parallel to each other. The width (pitch) of the optical comb teeth was 0.125 mm.
By moving the optical comb perpendicular to the optical axis of the transmitted light of the test piece, the amount of light (M) when the transmitted portion of the comb is on the optical axis and the amount of light (m) when there is a light-shielding portion of the comb are obtained. The ratio (C value (%)) of the difference between the two (M-m) and the sum (M + m) is a measure of image sharpness.
The C value is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more.

<Measurement of foreign matter number>
The film was placed on a horizontal table, and the light of the fluorescent lamp was reflected to visually observe the foreign matter.
◯: The number of foreign substances is 3 / m ² or less.
Δ: The number of foreign substances is ^{more than 3 / m 2} and 6 / m ² or less.
X: The number of foreign substances is more than ^{6 / m 2.}

<Bendability>
The frequency of cracking when the obtained optical film was folded in two was evaluated. ○ and △ are considered to be practically acceptable levels.
◯: Does not break at all △: May break once every few times ×: Always breaks

Table II and Table III summarize the manufacturing requirements and evaluation results of the acrylic resin film described above.

As is clear from the results shown in Table III, it can be seen that the acrylic resin film produced by the production method of the present invention has excellent transmission imageability, less foreign matter, and excellent bendability.

[Example 2]
<Preparation of organic matting agent 1>
(Preparation of seed particles)
1000 g of deionized water was placed in a polymer equipped with a stirrer and a thermometer, 50 g of methyl methacrylate and 6 g of t-dodecyl mercaptan were charged therein, and the mixture was heated to 70 ° C. while being replaced with nitrogen under stirring. The internal temperature was kept at 70 ° C., 20 g of deionized water in which 1 g of potassium persulfate was dissolved was added as a polymerization initiator, and then the mixture was polymerized for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

(Preparation of polymer particles)
In a polymerizer equipped with a stirrer and a thermometer, 800 g of deionized water in which 2.4 g of sodium lauryl sulfate was dissolved as a gelation inhibitor was placed therein, and 66 g of methyl methacrylate, 20 g of styrene and ethylene glycol were added thereto as a monomer mixture. A mixture of 64 g of dimethacrylate and 1 g of azobisisobutyronitrile as a polymerization initiator was added. Then, the mixed solution was added to T.I. A dispersion was obtained by stirring with a K homomixer (manufactured by Tokushu Kagaku Kogyo Co., Ltd.).

To the obtained dispersion, 60 g of the emulsion containing the seed particles was added, and the mixture was stirred at 30 ° C. for 1 hour to allow the seed particles to absorb the monomer mixture. Next, the absorbed monomer mixture was heated at 50 ° C. for 5 hours under a nitrogen stream for polymerization, and then cooled to room temperature (about 25 ° C.) to obtain polymer fine particles 1 (organic fine particles 1). , A slurry of the complex 1 containing sodium laurate (gelation inhibitor) adhering to the surface thereof was obtained. The average particle size of the obtained organic fine particles 1 was 0.14 μm.

(Preparation of aggregate of polymer particles)
This emulsion was spray-dried under the following conditions with a spray dryer (model: atomizer take-up method, model number: TRS-3WK) manufactured by Sakamoto Giken Co., Ltd. as a spray dryer to obtain an aggregate of the organic matting agent 1. .. The average particle size of the aggregate of the polymer particles was 30 μm.
Supply rate: 25 ml / min
Atomizer rotation speed: 11000 rpm
Air volume: 2m ³ / min
Slurry inlet temperature of spray dryer: 100 ° C
Polymer particle aggregate outlet temperature: 50 ° C

<Preparation of organic matting agent dispersion>
8.0 parts by mass of organic matting agent 1 and 400 parts by mass of methylene chloride were stirred and mixed with a dissolver for 50 minutes, and then dispersed under 1500 rpm conditions using a milder disperser (manufactured by Pacific Machinery & Engineering Co., Ltd.). , An organic matting agent dispersion was obtained.

<Manufacturing of optical film 201>
A dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressurized dissolution tank. Next, the acrylic resin (A-1) was charged into the pressurized dissolution tank with stirring. Next, the prepared rubber particle dispersion liquid and the organic matting agent dispersion liquid containing the following exemplary compound 176 as the additive 1 and the organic matting agent 1 as the additive 3 were added and heated to 60 ° C. Completely dissolved with stirring. The heating temperature was raised from room temperature at 5 ° C./min, dissolved in 30 minutes, and then lowered at 3 ° C./min. The obtained solution was filtered through a filter having a filtration accuracy of 30 μm, and then a dope was obtained.

(Composition of dope)
Acrylic resin (A-1): 84 parts by mass Methylene chloride: 43 parts by mass Ethanol: 50 parts by mass Rubber particle dispersion: 400 parts by mass Additive 1: 3 parts by mass Organic matting agent dispersion: 27.8 parts by mass

(Film formation)
Then, in the same manner as in the film formation in the production of the optical film 101, the obtained dope was used to obtain an optical film 201 having a film thickness of 40 μm.

<Manufacturing of optical films 202 to 211>
In the production of the optical film 201, the optical films 202 to 211 were produced in the same manner except that the types and amounts of the additives 1 to 3 were changed as shown in Table IV below.

The compounds shown in Table IV are as follows.

・ RZ-2: C ₁₂ H ₂₅ OP (= O)-(OK) ₂
・ RZ-10: C ₁₂ H ₂₅ OSO ₃ Na

<Evaluation of concave deformation>
Of the obtained film surfaces, the surface in contact with the metal belt was observed in 20 fields with a field of view of 2 mm × 2.7 mm of a laser microscope, and the number of concave shapes of 10 μm or more was counted. ○ and △ are considered to be practically acceptable levels.
〇: 0 to 1 piece △: 2 to 5 pieces ×: 6 pieces or more

<Evaluation of storage stability>
The film was cut into 1 cm squares, a 5 mm notch was made with a razor in parallel with the stretching direction of the tenter, and the film was attached to a glass plate with double-sided tape. The film together with the glass plate was stored in a constant temperature bath under cycle conditions of 60 ° C. 90% RH and 20 ° C. 90% RH reciprocating in 2 hours. After 100 cycles, the state of the notch was observed under a microscope. ○ and △ are considered to be practically acceptable levels. 〇: No change △: The notch progressed in the range of less than 1 mm ×: The notch progressed by 1 mm or more, or a crack occurred in a direction different from the notch

[Example 3]
<Manufacturing of optical films 301-303>
In the preparation of the rubber particle dispersion liquid in the production of the optical film 101, "formulation of the dispersion liquid (addition amount of rubber particles, methylene chloride, and presence / absence of addition of methanol)", "mixer / disperser and its conditions", " Optical films 301 to 303 were produced in the same manner except that "storage / addition and its conditions" were changed as shown in Table V below.

<Evaluation of internal haze>
Haze measured by dropping a few drops of glycerin on both sides of the obtained optical film (phase difference film) and sandwiching it between two 1.3 mm thick glass plates (MICRO SLIDE GLASS part number S9213, manufactured by MATSUNAMI). The value (%) obtained by subtracting the haze measured with a few drops of glycerin dropped between two glasses is shown in the table below.

[Example 4]
In the production of the optical film 101, an air curtain having a uniform width was installed in the casting portion immediately after the die, and a uniform dry air was blown to the wet casting film immediately after casting.
Adjusted so that the wind speed at the belt part is as shown in Table VI. In addition, the cast film at the location where the dry air was blown was in a state where the organic solvent was 300% with respect to the dry solid content.
With respect to the optical films 401 to 404 thus obtained, the film thickness deviations in the width direction were measured by scanning with a laser film thickness meter at a pitch of 0.5 mm and a width of 500 mm, respectively. The obtained film thickness profile in the width direction was converted into frequency units by Fourier transform, and the peak heights appearing at the spatial frequency of 1 cyc / 30 to 50 mm were compared relative to each other.

As can be seen from Table VI, by controlling the wind speed to 0.2 m / sec or less, the film thickness fluctuation with a period of 30 to 50 mm was significantly suppressed.

[Example 5] IR heater (total width)
During the production of the optical film 101, the IR heater was irradiated to the full width at the stage of peeling from the stainless belt support. After the irradiation, the film was made through a tenter in the same manner as the optical film 101, and used as an optical film 501.
For the IR heater, a line condensing type, water-cooled type, and mid-infrared radiation type (energy density 7 W / mm, focal length 20 mm, emission wavelength approximately 1 to 10 μm) manufactured by Hi-Beck Co., Ltd. were selected. The irradiation surface of the film was a surface not in contact with the belt, the irradiation distance was 20 mm, and the irradiation time was 3 minutes. The surface temperature of the heater unit at the time of irradiation was about 100 ° C.
The curl of the film was measured with the obtained optical films 501 and 101. It was confirmed that the optical film 501 generated less curl and had less ears on the edges of the film. In addition, the solvent (methylene chloride and ethanol) contained in each film was quantified in the state immediately before the introduction of the tenter during preparation, and the residual ratio was calculated.

<Measurement method of curl value>
A 4 cm square square is cut out from the created optical film in parallel to each of the MD and TD directions, and the humidity is adjusted overnight in an environment of 23 ° C. and 20%. Was averaged to obtain the curl value.
<Evaluation method for scratches>
The prepared optical film was cut into a width of 1 m and a length of 0.5 m, and the number of scratches extending in the length direction was counted by observation under a fluorescent lamp.
Solvent residual rate (%) = quantified mass of solvent / mass of dry film x 100
The absolute drying condition of the film was 120 ° C. for 60 minutes.

[Example 6] IR heater (end only)
During the production of the optical film 101, when the film was peeled off from the stainless belt support, the IR heater was applied only to the width of both ends of the film of 50 mm. The irradiation conditions were the same as those for 101. After the irradiation, it was prepared through a tenter in the same manner as 101, and used as an optical film 601.
The film thickness deviation in the width direction was measured with the obtained optical films 601 and 101.

<Measurement method of film thickness deviation>
The film width was divided into 10 parts, the film thickness was measured near the center of each section, and the standard deviation value of the 10-point data was taken as the film thickness deviation.

[Example 7]
The optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 were used as a base film (support) for a gas barrier film.

<Manufacturing of gas barrier film 1001>
(Support)
As the resin film support, the optical film (acrylic resin film) 101 produced in Example 1 was used.

The gas barrier film is produced by forming a bleed-out prevention layer on one side and a smooth layer on the other side by the following forming method while transporting the support at a speed of 20 m / min, and then forming an adhesive protective film. A rolled gas barrier film was obtained.

(Formation of bleed-out prevention layer)
A UV curable organic / inorganic hybrid hard coat material OPSTAR Z7535 manufactured by JSR Corporation is applied to one side of the support, and after drying, it is applied with a wire bar so that the film thickness is 4 μm, and then at 80 ° C. for 3 minutes. ^{After drying, it was cured at 500 mJ / cm 2} using a high-pressure mercury lamp in an air atmosphere to form a bleed-out prevention layer.

(Formation of smooth layer)
Subsequently, JSR Corporation's UV curable organic / inorganic hybrid hard coat material OPSTAR Z7501 was applied to the opposite surface of the support, and after being applied with a wire bar so that the film thickness after drying was 4 μm, the temperature was changed to 80 ° C. ^{After drying in 3 minutes, it was cured at 500 mJ / cm 2} using a high-pressure mercury lamp in an air atmosphere to form a smooth layer.
The maximum cross-sectional height Rt (p) at this time was 18 nm. The maximum cross-sectional height Rt (p) is calculated from the uneven cross-sectional curve continuously measured by an AFM (atomic force microscope) with a detector having a stylus with a minimum tip radius, and is calculated by a stylus with a minimum tip radius. The measurement is performed many times in a section where the measurement direction is 30 μm, and is the average roughness with respect to the amplitude of fine irregularities.

(Preparation of gas barrier layer)
Next, the following polysilazane coating solution was prepared on the smooth layer of the film provided with the smooth layer and the bleed-out prevention layer, and then the concentration was adjusted by diluting with dehydrated dibutyl ether to create a 23 ° C. 50% RH environment. After coating underneath, it was dried at 80 ° C. for 1 minute (the atmosphere during the process was adjusted to a dew point temperature of 10 ° C.) to prepare a polysilazane layer having a thickness of 150 nm after drying.

(Polysilazane coating liquid)
Aquamica NN120-20 (Perhydropolysilazane, manufactured by AZ Electronic Materials Co., Ltd., 20% by mass dibutyl ether solution)
(Reform treatment A)
The coated sample was reformed under the following conditions to form the first gas barrier layer. The dew point temperature during the reforming treatment was −8 ° C.

(Reform treatment equipment)
An excimer irradiation device MODEL: MECL-M-1-200 manufactured by MD.com Co., Ltd., a wavelength of 172 nm, a lamp-filled gas Xe, and a sample fixed on an operating stage were reformed under the following conditions.

(Reform treatment conditions)
Excimer light intensity 120mW / cm ² (172nm)
Distance between sample and light source 3 mm
Stage heating temperature 25 ℃
Oxygen concentration in the irradiation device 1000ppm (0.1%)
Actual excimer irradiation time 5 seconds Further, the concentration of the polysilazane compound coating solution was adjusted by diluting it with dehydrated dibutyl ether, and after coating in a 23 ° C. and 50% RH environment, 80 ° C. for 1 minute (in the process). The atmosphere was adjusted to a dew point temperature of 10 ° C.) and dried to prepare a polysilazane layer so that the film thickness after drying was 90 nm.

(Modification treatment B)
The sample coated with the second coated layer ^{was reformed at an integrated light intensity of 500 mJ / cm 2} and a stage heating temperature (substrate temperature at the time of VUV irradiation) of 25 ° C. to form the second layer of the gas barrier layer. The dew point temperature during the reforming treatment was −8 ° C. to obtain a gas barrier film 1001.

(Reform treatment equipment)
Same as reforming process A.

(Reform treatment conditions)
Excimer light intensity 120mW / cm ² (172nm)
Distance between sample and light source 3 mm
Oxygen concentration in the irradiation device 1000ppm (0.1%)
Reciprocating sample transfer at a stage movement speed of 10 mm / sec

<Manufacturing of gas barrier film 1002 to 1006>
In the production of the gas barrier film 1001, the gas barrier films 1002 to 1006 were produced in the same manner except that the supports were changed to the optical films 106, 107, 110 to 112, respectively.

≪Evaluation of gas barrier film≫
(Measurement of water vapor permeability)
<Measuring device for water vapor permeability>
Thin-film deposition equipment: Vacuum vapor deposition equipment JEE-400 manufactured by JEOL Ltd.
Constant temperature and humidity oven: Yamato Humanic Chamber IG47M
(raw materials)
Metal that corrodes by reacting with moisture: calcium (granular)
Water vapor impermeable metal: Aluminum (φ3-5mm, granular)

(Preparation of cell for water vapor barrier property evaluation)
Using a vacuum vapor deposition device (JEOL-400 vacuum vapor deposition device manufactured by JEOL Ltd.), mask the parts other than the parts (12 mm x 12 mm in 9 places) of the gas barrier films 1001 to 1006 before attaching the transparent conductive film. , Metallic calcium was deposited.
Then, the mask was removed in a vacuum state, and aluminum was vapor-deposited on the entire surface of one side of the sheet from another metal vapor deposition source. After sealing the aluminum, the vacuum state is released, and the quartz glass with a thickness of 0.2 mm is immediately faced with the aluminum sealing side via a UV curable resin for sealing (manufactured by Nagase ChemteX) in a dry nitrogen gas atmosphere. And by irradiating with ultraviolet rays, an evaluation cell was prepared.
The obtained sample with both sides sealed was stored at 60 ° C. and 90% RH under high temperature and high humidity, and based on the method described in JP-A-2005-283561, the moisture permeated into the cell from the amount of corrosion of metallic calcium. The amount was calculated.

(Rank evaluation)
5: 1 x 10 ^-4 g / m ² / day or less 4: 1 x 10 ^-4 g / m ² / day or more 1 x 10 ^-3 g / m ² / day or less 3: 1 x 10 ^-3 g / m ² / day or more, 1 x 10 ^-2 g / m ^{less than 2} / day 2: 1 x 10 ^-2 g / m ² / day or more, 1 x 10 ^-1 g / m ² / day less than 1: 1 x 10 ^-1 g / m ² / day or more In the rank evaluation, the practical range is rank 3 or more.

(Heat resistance test of gas barrier film)
The gas barrier films 1001 to 1006 immediately after production were stored in an environment of 85 ° C. for 7 days, and then the water vapor transmittance was measured in the same manner as above to evaluate the deterioration (durability) due to heat.

(Durability test of gas barrier film)
The deterioration (durability) of the gas barrier properties after repeating bending of the gas barrier films 1001 to 1006 immediately after production 100 times at an angle of 180 degrees so as to have a curvature of 10 mm in radius is the same as above. It was evaluated by the water vapor permeability.
As a result of the above evaluation, it was confirmed that the optical film of the present invention showed rank 3 or higher for all the evaluation items and was an excellent support for the gas barrier film.

[Example 8]
The optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 were used as a base film (support) for a touch panel.

(Preparation of transparent board)
The following hard coat layer coating liquid was applied to both surfaces of the optical films 101, 106, 107, 110 to 112 with a die coater to form a coating film to be a hard coat layer. After drying the coating film at 70 ° C., the illuminance of the irradiated portion was 300 mW / cm ² and the irradiation amount was 0. ^{The coating film was cured at 3} J / cm 2, and further heat-treated at 130 ° C. for 5 minutes in the heat-treated zone to prepare transparent substrates 1101-1106. The film thickness of the hard coat layer after curing was 5 μm, respectively.

(Preparation of hard coat layer coating liquid)
Each of the following constituent materials was mixed, stirred and dissolved to prepare a hard coat layer coating liquid.

・ Hard coat layer coating liquid Pentaerythritol tetraacrylate: 30 parts by mass Dipentaerythritol hexaacrylate: 60 parts by mass Dipentaerythritol pentaacrylate: 50 parts by mass Irgacure 184 (manufactured by BASF Japan Co., Ltd.): 5 parts by mass Irgacure 907 (BASF) Japan Co., Ltd.): 5 parts by mass ZX-212 (Fluorine-siloxane graft polymer, manufactured by T & K Toka Co., Ltd.): 5 parts by mass Seahoster KEP-50 (powdered silica particles, average particle size 0.47 to 0) .61 μm, manufactured by Nippon Catalyst Co., Ltd.): 24.3 parts by mass propylene glycol monomethyl ether: 20 parts by mass Methyl acetate: 40 parts by mass Methyl ethyl ketone: 60 parts by mass

(Manufacturing of conductive film 1101)
An intermediate layer (thickness 25 nm) is formed on one side of the transparent substrate 1101 by the vapor deposition method using the following compound 1, and subsequently, an electrode layer (thickness 8 nm) made of silver (Ag) is formed by the vapor deposition method. bottom. Further, a surface protective layer (thickness 30 nm) made of titanium oxide (TiO _{2) was subsequently formed by a thin-film deposition method.} As a result, a conductive film 1101 having a transparent electrode having a three-layer structure consisting of an intermediate layer, a transparent conductive layer, and a surface protective layer was produced.

At this time, first, the transparent substrate 1101 was fixed to the base material holder of a commercially available vacuum vapor deposition apparatus. Further, the compound 1 was placed in a tantalum resistance heating boat. These substrate holders and the heating boat were attached to the first vacuum chamber of the vacuum vapor deposition apparatus. In addition, silver (Ag) was placed in a tungsten resistance heating boat and installed in the second vacuum chamber. Further, titanium oxide (TiO ₂ ) was put into a tantalum resistance heating boat and installed in a third vacuum chamber.

Next, after depressurizing the first vacuum chamber to 4 × 10 ^-4 Pa, the heating boat containing each compound is energized and heated, and the vapor deposition rate is 0.1 to 0.2 nm / sec on the transparent substrate 1101. An intermediate layer having a film thickness of 25 nm was provided.

Next, the transparent substrate 1101 having a film formed up to the intermediate layer is transferred to the second vacuum chamber in a vacuum state, the second vacuum chamber is ^{depressurized to 4 × 10 -4} Pa, and then a heating boat containing silver is energized to heat the transparent substrate 1101. bottom. As a result, a transparent conductive layer made of silver having a film thickness of 8 nm was formed at a vapor deposition rate of 0.1 to 0.2 nm / sec.

Next, the transparent substrate 1101 on which the intermediate layer and the electrode layer were formed was transferred to the third vacuum chamber in a vacuum state, the third vacuum chamber ^{was depressurized to 4 × 10 -4} Pa, and then titanium oxide (TiO ₂ ) was added. The heating boat was energized and heated. As a result, a surface protective layer made of _{titanium oxide (TiO 2} ) having a film thickness of 30 nm was formed at a vapor deposition rate of 0.1 to 0.2 nm / sec.

Through the above steps, a conductive film 1101 having a laminated structure of an intermediate layer, a transparent conductive layer on the intermediate layer, and a surface protective layer was obtained.

The vapor deposition film thickness is determined by J. A. Woollam Co. Inc. It was measured with a VB-250 type VASE ellipsometer manufactured by VB-250.

(Manufacturing of conductive film 1102-1106)
In the same manner as the conductive film 1101, the optical films 106, 107, 110 to 112 were used to prepare the conductive films 1102-1106.

≪Evaluation of each sample≫
For the produced conductive films 1101-1106, bending resistance, interference unevenness, and deterioration of surface resistivity after moist heat durability were measured.

(Bending resistance)
The prepared conductive film was evaluated for bending resistance according to the method specified in JIS K 5400. In the evaluation of bending resistance, a stainless rod having a diameter of 10 mm was used for winding the conductive film sample.
The state of the electrode layer was ranked as follows.
⊚: No change ○: Slightly deformed, but no problem in practical use △: Fine cracks occurred in the electrode layer ×: Cracks occurred in the electrode layer

(Color unevenness)
Remove the touch panel of iPad (registered trademark) (Apple 9.7-inch IPS liquid crystal tablet computer), and pass the produced conductive film through a 25 μm double-sided adhesive tape (Lintech base materialless tape MO-3005C). , The conductive layer was bonded so as to face the display surface. White was displayed on the display, and the display surface was observed through polarized sunglasses at an angle of 45 °.
As a result of the test, the rank was evaluated as follows.
⊚: No color unevenness was observed ○: Slight color unevenness was observed, but there was no problem in practical use △: Color unevenness was observed ×: Very dark rainbow-like color unevenness was observed.

(Deterioration of surface resistance due to durability against heat and humidity)
After leaving the sample for which the surface resistivity was measured for 300 hours in an environment of a temperature of 60 ° C. and a relative humidity of 90% RH, the surface resistivity values at any 10 points were measured, and the average value was calculated after the wet and heat endurance of the sample. The surface resistivity was used.
As a result of the test, the rank was evaluated as follows.
When [Deterioration of surface resistivity] = [(Surface resistivity after moist heat endurance)-(Surface resistivity before moist heat endurance)] / [Surface resistivity before moist heat endurance]
⊚: Surface resistance deterioration is less than ± 10% ○: Surface resistance deterioration is ± 10% or more and less than ± 20% Δ: Surface resistance deterioration is ± 20% or more and less than ± 30% × : The surface resistance deterioration is ± 30%. As a result of the above evaluation, those using the optical film of the present invention were evaluated as ○ or more, and the support of the excellent conductive film for the touch panel. I confirmed that.

[Example 9]
The optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 were used as substrate films (supports) for flexible organic electroluminescence devices, respectively.

Transparent conductive films 1201 to 1206 were prepared by forming thin films of a clear hard coat layer (both sides), a moisture-proof film (both sides), and a transparent conductive film (one side) in this order on the film.

<Preparation of clear hard coat layer>
The following hard coat layer coating composition is coated on the optical film 101 with an extrusion coater so as to have a film thickness of 3 μm, then dried in a dry portion set at 80 ° C. for 1 minute, and then irradiated with ultraviolet rays at ^{120 mW / cm 2.} Formed by

(Clear hard coat layer coating composition)
Dipentaerythritol hexaatarilate monomer: 60 parts by mass Dimer of dipentaerythritol hexaatarilate dimer: 20 parts by mass Ingredients of dipentaerythritol hexaatarilate trimer or more: 20 parts by mass Dimethoxybenzophenylone: 4 parts by mass Ethyl acetate: 50 parts by mass Methinole ethyl ketone: 50 parts by mass Isopropyl alcohol: 50 parts by mass

<Making a moisture-proof film>
As the plasma discharge device, a parallel plate type electrode was used, the substrate film was placed between the electrodes, and a mixed gas was introduced to form a thin film.
The following electrodes were used. A 200 mm x 200 mm x 2 mm stainless steel plate is coated with a high-density, high-adhesion alumina sprayed film, then a solution of tetramethoxysilane diluted with ethyl acetate is applied and dried, and then cured by ultraviolet irradiation to seal the holes. Further, the surface of the dielectric coated in this way was polished and smoothed, and processed so that the surface roughness Ra was 5 μm. The electrodes were prepared in this way and grounded. On the other hand, as the applied electrodes, a plurality of hollow square-shaped pure titanium pipes coated with the same dielectric as described above under the same conditions were produced and used as facing electrode groups.

The power supply used for plasma generation is a high-frequency power supply JRF-10000 manufactured by JEOL Ltd., which supplies a voltage of 13.56 MHz and ^{a power of 5 W / cm 2} , and a mixed gas having the following composition between the electrodes. Shed.

Inert gas (argon) 99.3% by volume
Reactive gas 1 (hydrogen): 0.5% by volume
Reactive gas 2 (tetraethoxysilane): 0.3% by volume
On the clear hard coat layer of the optical film 101 provided with the clear hard coat layer, atmospheric pressure plasma treatment was performed according to the above reaction gas and reaction conditions to prepare silicon oxide films having a thickness of 18 nm as moisture-proof films.

<Manufacturing of transparent conductive film>
A transparent conductive film was prepared by flowing a mixed gas having the following composition under the same atmospheric pressure brazma conditions as the formation of the moisture-proof film except that the power supply was changed to 12 W / cm ^2.

Inert gas (helium): 98.69% by volume
Reactive gas 1 (hydrogen): 0.05% by volume
Reactive gas 2 (indium acetylacetonate): 1.2% by volume
Reactive gas 3 (dibutyltin diacetate): 0.05% by volume
Reactive gas 4 (tetraethoxysilane): 0.01% by volume
Atmospheric pressure plasma treatment was performed on the silicon oxide layer of the optical film 101 provided with the clear hard coat layer and the silicon oxide layer according to the above reaction gas and reaction conditions to prepare a tin-doped indium oxide film (ITO film) as a transparent conductive film. (Thickness 110 nm), a transparent conductive film 1201 was used.

<Transparent Conductive Film 1202-1206>
Similar to the transparent conductive film 1201, the optical film films 106, 107, 110 to 112 were used to prepare the transparent conductive film 1202 to 1206.
The transparent conductive films 1201 to 1206 thus obtained were evaluated as follows.

≪Evaluation≫
(Transmittance)
It was measured with TURBIDITY METER T2600DA manufactured by Tokyo Denshoku.

(Evaluation of moisture permeability)
The moisture permeation was measured under the conditions described in JIS Z-0208 (40 ° C., 90% RH).

Further, the measurement was also carried out after performing a series of cooling and ripening cycles of heating at 180 ° C. for 1 hour and then allowing to cool at room temperature for 1 hour 10 times.

(Specific resistance)
It was determined by the four-terminal method according to JIS R-1637. For the measurement, Mitsubishi Chemical's Lorester cyclic polyolefin film GP, MCP-T600 was used.

As a result of the above evaluation, it was confirmed that the optical film of the present invention is an excellent support for the conductive film.

<Method of manufacturing organic EL element>
The transparent conductive film was used as the transparent conductive film, and the transparent conductive film (positive electrode) was patterned on the transparent conductive film. Then, it was ultrasonically washed with a neutral detergent, acetone and ethanol, and then pulled out of boiling ethanol and dried. Next, after ultrasonically cleaning the surface of the transparent conductive film, N, N-diphenyl-m-trill-4,4'-diamine-1,1'-biphenyl (TPD) was deposited at a vapor deposition rate of 0.2 nm / The film was deposited to a thickness of 55 nm in sec to form a hole injection transport layer.

Further, Alq ₃ : tris (8-quinolinolat) aluminum was vapor-deposited to a thickness of 50 nm at a vapor deposition rate of 0.2 nm / sec to obtain an electron-injection transport light emitting layer. Next, a negative electrode was formed into a film having a thickness of 200 nm using an Al / Su alloy (Su: 10 at%) as a target by a DC sputtering method using a sputtering device. Ar was used as the sputter gas at this time, the gas pressure was 3.5 Pa, and the distance between the target and the substrate (Ts) was 9.0 cm. The input power was 1.2 W / cm ² .
Finally, SiO ₂ was sputtered to a thickness of 200 nm to obtain an organic EL light emitting device as a protective layer. In this organic EL light emitting element, two parallel striped negative electrodes and eight parallel striped electrodes are orthogonal to each other, and 2 × 2 mm vertical and horizontal element units (pixels) are arranged at intervals of 2 mm from each other. , A 16-pixel element.

When the organic EL element thus obtained was driven at 9 V, the transparent conductive films 1201 to 1206 using the optical film of the present invention obtained a brightness of ^{350 cd / m 2 or more.}

According to the present invention, it is possible to provide an excellent transparent film for a display substrate, such as for an organic EL display having a high glass transition temperature and a low linear expansion rate, or for a touch panel.

[Example 10]
The optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 were used as a base film (support) for nanoimprint.

(Making a mold by laser interference exposure)
A resist is applied to a quartz glass substrate (thickness 1.2 mm, 70 mm square) by spin coating. As the resist material, a positive resist that removes the resist in the exposed portion is used.
A fine pattern is drawn on the resist using the immersion exposure optical system. The immersion exposure optical system uses an ultraviolet laser (wavelength 266 nm) to irradiate two light fluxes at an inclination of 15 degrees with respect to the normal direction of the quartz glass substrate to form a first interference fringe on the resist, and the first. Is exposed. As the laser light source, "MBD266 manufactured by Coherent Co., Ltd." is used. Next, the quartz glass substrate is rotated 90 degrees to form a second interference fringe orthogonal to the first interference fringe, and the second exposure is performed. In the first exposure and the second exposure, development is performed so that only the portion where the bright portions of the interference fringes intersect remains. By the above process, a resist in which holes having a pitch of 300 nm and a depth of 150 nm are regularly arranged is formed on a quartz glass substrate. A fine hole structure (pitch 300 nm, depth 150 nm) having a drawing size of 50 mm square was formed on quartz glass by dry etching.

(Release processing of quartz glass substrate)
_{Tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane [CF 3-} (CF ₂ ) _5- CH _2- CH ₂ SiCl ₃ ], which is a chlorine-based fluororesin-containing silane coupling agent, is made of quartz glass. The mold was surface-treated to form a chemically adsorbed film of fluororesin on the finely shaped surface.

(Preparation of liquid composition)
Polymethylmethacrylate (PMMA) was prepared as a resin and dissolved in toluene to prepare a liquid composition. The mass ratio of the resin and the solvent was set to 1/20 (5%).

(Application of liquid composition)
The liquid crystal composition was applied onto a quartz glass substrate with a wire bar at a wet film thickness of 80 μm.

(Attachment of film)
Within 5 seconds after the liquid composition was applied, the optical films 101, 106, 107, 110-112 were brought into close contact with each other and bonded to the applied liquid composition.

(Dry)
The quartz glass substrate coated with the liquid composition and the optical film were bonded and dried at room temperature for 55 seconds.

(Release)
After drying, the film was released, and a pillar shape having a pitch of 300 nm and a height of 150 nm was transferred onto the film. When the surface was observed with a scanning microscope, it had excellent uniformity in both pitch and height.

From the above, the optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 are excellent in use as a base film (support) for nanoimprint.

[Example 11]
The optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 were used as a base film (support) for a flexible electronic circuit.

(Manufacturing of substrate 1 with anchor layer)
<Synthesis of polymerizable compound 1 having an ethylenically unsaturated group>
A polymerizable compound 1 having an ethylenically unsaturated group as a polymerizable group was synthesized according to the following procedure.
20 ml of ethylene glycol diacetate, 7.43 g of hydroxyethyl acrylate and 32.08 g of cyanoethyl acrylate were added to a 500 ml three-necked flask, and the temperature was raised to 80 ° C., and then an oil-soluble azo polymerization initiator was added therein. A mixed solution of 0.737 g of V-601 (dimethyl-2,2'-azobis (2-methylisopropionate)) and 20 ml of ethylene glycol diacetate was added dropwise over 4 hours, and after the addition was completed, another 3 was added. Reacted for time.

To the above reaction solution, 0.32 g of di-tert-butylhydroquinone, 1.04 g of Neostan U-600 (bismuth octylate, manufactured by Nitto Kasei), and Karenz AOI (acroxyethyl isocyanate, Showa) as a photocurable resin additive. 21.87 g of Denko Co., Ltd. and 22 g of ethylene glycol diacetate were added, and the reaction was carried out at 55 ° C. for 6 hours. Then, 4.1 g of methanol was added to the reaction solution, and the reaction was further carried out for 1.5 hours. After completion of the reaction, the reaction was reprecipitated with water, and the solid substance was taken out to obtain a polymerizable compound 1 having a nitrile group as an interacting group.

The polymerizable compound 1 had a repeating unit containing a polymerizable group (an ethylenically unsaturated group): a repeating unit containing a nitrile group = 22:78 (molar ratio). The molecular weight was Mw = 82,000 (Mw / Mn = 3.4) in terms of polystyrene.

<Preparation of anchor layer coating liquid 1>
10 parts by mass of the above-prepared polymerizable compound 1 and 90 parts by mass of acetonitrile were mixed and stirred to prepare an anchor layer coating liquid 1 having a solid content of 10% by mass.

<Formation of anchor layer 1>
The optical film 101 produced in Example 1 is used as a substrate, and the surface thereof is treated with oxygen plasma, and then the anchor layer coating liquid 1 is applied by a spin coating coating method so that the film thickness after drying is 1.0 μm. And dried at 80 ° C. for 30 minutes.

<Hardening treatment of anchor layer 1>
Next, using a UV irradiation lamp (model number: UVF-502S, lamp: UXM-501MD) manufactured by Sannaga Electric, an irradiation power of 1.5 mW / cm2 (UV integrated photometer UIT150-light receiving sensor UVD-S254 manufactured by Ushio Electric). Irradiation power was measured), and ultraviolet irradiation was performed under the condition that the integrated light amount was 500 mJ / cm ^{2, and the anchor layer 1 was cured.} This curing condition is referred to as condition A.

The anchor layer 1 cured under the above condition A is isolated and subjected to an extraction treatment at 25 ° C. for 12 hours in an acetone solution, and then the mass of the anchor layer before the treatment is W1 (g) and the anchor layer after the acetone extraction is performed. When the mass of was W2 (g), the gel fraction was calculated by the following formula. As a result of the measurement, the gel fraction of the anchor layer 1 was 93%.
Gel fraction (%) = (W2 / W1) x 100

<< Fabrication of metal pattern >>
[Making metal pattern 1]
Using the substrate 1 with an anchor layer produced above, a metal pattern 1 was produced according to the following metal pattern forming step.

(Metal pattern forming process)
1: Catalyst ink application process 2: Drying process 3: Surface treatment process 4: Activation process 5: Electroless plating process 6: Electroplating process

(1: Catalyst ink application process)
<Preparation of catalyst ink 1>
The catalyst ink 1 was prepared by mixing the following additives.
Electroless plating catalyst precursor: Palladium acetate: 0.05% by mass
2 Ethylene acetate: 79.95% by mass
t-Butyl alcohol: 20% by mass

<Addition of catalyst ink 1>
Using an inkjet recording head, the catalyst ink 1 prepared above is used to draw patterns of 75 μm, 100 μm, 150 μm, and 200 μm lines and spaces on the anchor layer of the formed substrate 1 with an anchor layer, and sample 1 is drawn. Was produced.
As the inkjet recording head used, a 512S head manufactured by Konica Minolta Co., Ltd., which is capable of ejecting 4pl size ink droplets by a piezo method, was used.

(2: Drying process)
After the catalyst ink 1 was applied, warm air at 50 ° C. was blown onto the catalyst ink-applied surface for 10 minutes to dry the catalyst ink 1.

(3: Surface treatment process)
The dried sample 1 was subjected to a surface treatment method according to the following method.

<Surface treatment method>
The sample 1 was immersed in a 10% by mass solution of a plating conditioner containing a nonionic surfactant (trade name: PC-321, manufactured by Meltac) at 60 ° C. for 5 minutes for surface treatment.
As a result of measuring the contact angles of the surface-treated sample 1 and the untreated sample with water, it was confirmed that the contact angle was reduced by 20% or more due to the surface treatment.

(4: Activation step)
Next, the surface-treated sample 1 was immersed in the following activation solution at 35 ° C. for 10 minutes to perform the activation treatment.

<Activator>
"Measure by photographing either the reflected light or the transmitted light emitted from the opposite surface.
Alcup MRD2-A (manufactured by Uyemura Kogyo Co., Ltd.): 18 ml
Alcup MRD2-C (manufactured by Uyemura Kogyo Co., Ltd.): 60 ml
Finished to 1000 ml with pure water.

(5: Electroless plating process)
The following electroless copper plating solution was adjusted to 13.0 in pH with sodium hydroxide, and then electroless plating was performed on sample 1 that had undergone 5: activation treatment at a temperature of 50 ° C. to obtain about 0. A copper plating layer having a thickness of .2 μm was formed.

<Electroless copper plating solution>
Melplate CU-5100A (manufactured by Meltex Inc.): 60 ml
Melplate CU-5100B (manufactured by Meltex Inc.): 55 ml
Melplate CU-5100C (manufactured by Meltex Inc.): 20 ml
Melplate CU-5100M (Meltex Inc.): 40 ml
Finished to 1000 ml with pure water.

The electroless copper plating solution has a copper concentration of 2.5% by mass, a formalin concentration of 1% by mass, and an ethylenediaminetetraacetic acid (EDTA) concentration of 2.5% by mass.

(6: Electroplating process)
The sample 1 subjected to the electroplating-free plating treatment is immersed in an electroplating bath ^{, an electroplating is performed at a current density of 1.5 A / dm 2} using a copper plate as an anode, and a copper film of about 15 μm is formed to form a metal pattern. 1 was produced.

<Preparation of electroplating bath>
Copper sulfate pentahydrate: 60 g
Sulfuric acid: 190g
Chloride ion: 50 mg
Copper Gleam PCM (Meltex Inc.): 5 ml
Finished to 1000 ml with pure water.

In the same manner as in the above steps, the optical films 106, 107, 110-112 were used as the base film (support) for the flexible electronic circuit.

<< Evaluation of metal pattern >>
The following evaluations were performed for each of the metal patterns produced above.

[Evaluation of plating quality]
The drawn 75 μm, 100 μm, 150 μm, and 200 μm line and space patterns of the samples processed up to the electroless plating step of each metal pattern were visually observed, and the image quality was evaluated according to the following criteria.

◯: Line & space pattern after electroless plating is good quality with no abnormal precipitation outside the printed area and no deterioration of plating gloss or cracks. △: Line & space pattern after electroless plating is completed. In the space pattern, abnormal precipitation occurs slightly outside the printed area, but no deterioration in plating gloss or cracks is observed. ×: Abnormal precipitation outside the printed area in the line & space pattern after electroless plating is completed. , The gloss of the plating is reduced, or cracks are generated. Practically, △ or more is within the permissible range.

[Evaluation of durability (adhesion resistance) in high temperature and high humidity environment]
Each metal pattern produced above was stored for 7 days in a high temperature and high humidity environment of 80 ° C. and 90% RH, and then immediately heat-treated on a hot plate at 240 ° C. and 260 ° C. to obtain a substrate and a copper plating pattern. The adhesion between them (presence or absence of blister generation) was visually observed, and the durability (adhesion resistance) was evaluated according to the following criteria.

◯: No blister is observed between the substrate and the copper plating pattern even when heated to 260 ° C. on the hot plate Δ: Even when heated to 240 ° C. on the hot plate, between the substrate and the copper plating pattern. No blister is observed, but some blister is observed when heated at 260 ° C. ×: When heated to 240 ° C on a hot plate, blister is clearly observed between the substrate and the copper plating pattern. As a result of the above evaluation, all the samples for which a metal pattern was prepared using the optical films 101, 106, 107, 110-112 of the present invention were evaluated as Δ to ○, and were excellent for flexible electronic circuits. It turned out to be a base film (support).

[Example 12]
The optical films 101, 106, 107, 110-112 of the present invention produced in Example 1 were used as a base film (support) for an anti-counterfeiting medium.

(Preparation of coating liquid AL-1 for alignment layer)
The following composition was prepared, filtered through a polypropylene filter having a pore size of 30 μm, and used as a coating liquid AL-1 for an alignment layer.

<Coating liquid composition for alignment layer>
Polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.): 3.21% by mass
Polyvinylpyrrolidone (Luvitec K30, manufactured by BASF Japan Ltd.): 1.48% by mass
Distilled water: 52.10% by mass
Methanol: 43.21% by mass

(Preparation of coating liquid AL-2 for alignment layer)
The following composition was prepared, filtered through a polypropylene filter having a pore size of 30 μm, and used as a coating liquid AL-2 for an alignment layer.

<Coating liquid AL-2 composition for alignment layer>
Liquid crystal alignment agent (AL-1-1): 1.0% by mass
Tetrahydrofuran: 99.0% by mass

(Preparation of coating liquid LC-1 for optically anisotropic layer)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid LC-1 for an optically anisotropic layer.

LC-1-1 is a liquid crystal compound having two reactive groups, one of which is an acrylic group which is a radical reactive group and the other is an oxetane group which is a cationic reactive group. be.

<Coating liquid composition for optically anisotropic layer>
Polymerizable liquid crystal compound (LC-1-1): 32.88% by mass
Horizontal alignment agent (LC-1-2): 0.05% by mass
Cationic Photopolymerization Initiator (CPI100-P, manufactured by Sun Appro Co., Ltd.): 0.66% by mass
Polymerization control agent (IRGANOX1076, manufactured by BASF Japan Ltd.): 0.07% by mass
Methyl ethyl ketone: 46.34% by mass
Cyclohexanone: 20.00% by mass

(Preparation of coating liquid LC-2 for optically anisotropic layer)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid LC-1 for an optically anisotropic layer.

<Coating liquid LC-1 composition for optically anisotropic layer>
Diacrylate liquid crystal compound (Pariocolor LC242 (trade name, manufactured by BASF Japan Ltd.)): 31.53% by mass
Photopolymerization initiator (IRGACURE907 (trade name, manufactured by BASF Japan Ltd.)): 0.99% by mass
Alkylthioxanthone (Kayacure DETX-S (trade name, manufactured by Nippon Kayaku Co., Ltd.)): 0.33% by mass
Fluorine-based surfactant (Megafuck F-176PF (trade name, manufactured by DIC Corporation)): 0.15% by mass
Methyl ethyl ketone: 67.00% by mass

(Preparation of additive layer OC-1)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid OC-1 for a transfer adhesive layer. 2-Trichloromethyl-5- (p-styrylstyryl) 1,3,4-oxadiazole was used as the radical photopolymerization initiator RPI-1. The following composition is the amount used as the solution.

<Coating liquid composition for additive layer>
Binder (MH-101-5, manufactured by Fujikura Kasei Co., Ltd.): 7.63% by mass
Radical Photopolymerization Initiator (RPI-1): 0.49% by mass
Surfactant (Megafuck F-176PF, manufactured by DIC Corporation): 0.03% by mass
Methyl ethyl ketone: 91.85% by mass

(Manufacturing of birefringence pattern manufacturing material P-1)
Aluminum was vapor-deposited on the optical film 101 at 60 nm to prepare a support with a reflective layer. The coating liquid AL-1 for an alignment layer was applied onto the surface on which the aluminum was vapor-deposited using a wire bar, and dried. The dry film thickness was 0.5 μm. After rubbing the alignment layer, the coating liquid LC-1 for an optically anisotropic layer is applied using a wire bar, dried at a film surface temperature of 90 ° C. for 2 minutes to obtain a liquid crystal phase state, and then 160 W under air. An optically anisotropic layer having a thickness of 4.5 μm was formed by irradiating ultraviolet rays with a / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) to fix the orientation state. ^{The illuminance of the ultraviolet rays used at this time was 500 mW / cm 2} in the UV-A region (integration of wavelengths of 320 to 400 nm), and the irradiation amount was 500 mJ / cm ² in the UV-A region. The retardation of the optically anisotropic layer was 400 nm, and it was a solid polymer at 20 ° C. Finally, the coating liquid OC-1 for the additive layer was applied onto the optically anisotropic layer and dried to form an additive layer having a thickness of 0.8 μm, thereby producing a birefringence pattern producing material P-1.

(Anti-counterfeit medium A: Patterned birefringence pattern of retardation)
Digital exposure machine P-1 by laser scanning exposure, as shown in FIG. 42 at (INPREX IP-3600H, produced by Fujifilm ^{Corp.), 0mJ / cm 2, 8mJ} / cm 2, the exposure amount of 25 mJ / cm ² The pattern was exposed by roll-to-roll using. In the figure, the exposure amount is 0 mJ / cm ² of the area indicated by solid color, exposure so that the exposure amount of the region indicated exposure region illustrated by horizontal lines 8 mJ / cm ^2, a vertical line is 25 mJ / cm ² bottom. Then, using a far-infrared heater continuous furnace, the article P-2 having a birefringence pattern was produced by heating with a roll-to-roll for 20 minutes so that the film surface temperature became 210 ° C. When a polarizing plate (HLC-5618, manufactured by Sanritz Co., Ltd.) was held over the article P-2, the birefringence pattern applied to the article P-2 could be confirmed when the polarizing plate (HLC-5618, manufactured by Sanritz Co., Ltd.) was held over the article P-2. rice field. FIG. 43 shows an enlarged view of the pattern observed on the article P-2 via the polarizing plate. In the figure, a two-color pattern is observed in which the ground aluminum foil is silver, while the lattice portion is dark blue to light blue, and the shaded portion is yellow to orange.

(Anti-counterfeit medium B :: Patterned birefringence pattern of the optical axis)
Aluminum was vapor-deposited on the optical film 101 at 60 nm. Next, the coating liquid AL-2 for the alignment layer was applied onto the aluminum using a wire bar and dried. The dry film thickness was 0.1 μm.

The photomask A shown in FIG. 44 is placed on the obtained organic film, and a linear polarizing plate is used to convert the light emitted from the ultraviolet light emitted from the ultraviolet irradiator (manufactured by HOYACANDEO OPTRONICS, trade name: EXECURE3000). Through, irradiation was performed for 1 second at an intensity of ^{100 mW / cm 2} (365 nm) from the direction perpendicular to the support. At this time, the polarizing plate was arranged so that the azimuth angle of the absorption axis of the linear polarizing plate was 0 ° with respect to the long side of the photomask.

Subsequently, the photomask is changed in the order of B, C, and D shown in FIG. 44 so that the absorption axes of the linear polarizing plate are 45 °, 90 °, and 135 ° with respect to the long side of the photomask, respectively. Was placed and then irradiated with ultraviolet rays in the same manner.

Next, the coating liquid LC-2 for an optically anisotropic layer was applied using a wire bar, dried at a film surface temperature of 105 ° C. for 2 minutes to obtain a liquid crystal phase state, and then air- ^{cooled at 160 mW / cm 2} under air. An optically anisotropic layer with a thickness of 0.9 μm is fixed by irradiating ultraviolet rays with ^{an illuminance of 400 mW / cm 2} and an irradiation dose of 400 mJ / cm ² using a metal halide lamp (manufactured by Eye Graphics Co., Ltd.). By forming the above, an anti-counterfeit medium B having the pattern shown in the plan view of FIG. 45 was produced.

As shown in FIG. 45, the slow axes of the characters A212, B213, C214, and background 215 of the anti-counterfeit medium B were 0 °, 45 °, 90 °, and 135 ° with respect to the long side, respectively. The retardation in these regions was 135 nm (λ / 4).

(Manufacturing Example 1)
The anti-counterfeit medium A was treated with a surface modifier MEIR-5-600 (manufactured by MD Excimer). Then, letters and patterns were printed on letterpress using UV161 ink, safflower, indigo, and yellow (manufactured by T & K). Then, dry lamination was performed using Suncut PL Shin 7LK (manufactured by Lintec Corporation, front retardation = 5 nm, film thickness 50 μm) to prepare an anti-counterfeit medium of Production Example 1.

(Manufacturing Example 2)
The anti-counterfeit medium of Production Example 2 was produced in the same manner as in Production Example 1 except that the anti-counterfeit medium A was used as the anti-counterfeit medium B.

(Manufacturing Example 3)
Anti-counterfeiting medium of Production Example 3 as in Production Example 1 except that Suncut PLS IN 7LK (manufactured by Lintec Corporation, front retardation = 5 nm, film thickness 50 μm) whose surface is sandblasted is used as the laminated film. Was produced.

(Manufacturing Example 4)
Variable information was printed with KI ink using LUXEL JET UV250GT (manufactured by FUJIFILM Corporation) on the anti-counterfeiting medium of Production Example 1. In this way, the anti-counterfeit medium of Production Example 4 was produced.

(Manufacturing Example 5)
The anti-counterfeit medium A was treated with a surface modifier MEIR-5-600 (manufactured by MD Excimer). Then, using LUXEL JET UV250GT (manufactured by FUJIFILM Corporation), printing was performed with KI ink. Then, dry lamination was performed using Suncut PL Shin 7LK (manufactured by Lintec Corporation, front retardation = 5 nm, film thickness 50 μm) to prepare an anti-counterfeit medium of Production Example 5.

(Manufacturing Example 6)
The anti-counterfeit medium A was treated with a surface modifier MEIR-5-600 (manufactured by MD Excimer). Then, letters and patterns were printed on a letterpress using UV flexo 500 ink, safflower, indigo, and yellow (manufactured by T & K). Then, dry lamination was performed using Suncut PL Shin 7LK (manufactured by Lintec Corporation, front retardation = 5 nm, film thickness 50 μm) to prepare an anti-counterfeit medium of Production Example 6.

(Manufacturing Example 7)
The anti-counterfeit medium A was treated with a surface modifier MEIR-5-600 (manufactured by MD Excimer). After that, characters and patterns were screen-printed. Then, dry lamination was performed using Suncut PL Shin 7LK (manufactured by Lintec Corporation, front retardation = 5 nm, film thickness 50 μm) to prepare an anti-counterfeit medium of Production Example 6.

(Manufacturing Example 8)
The anti-counterfeit medium of Production Example 8 was prepared in the same manner as in Production Example 1 except that KES25N Matt PLS Thin 7LK (manufactured by Lintec Corporation, front retardation = 33 nm, film thickness 25 μm) was used as the laminate film.

(Manufacturing Example 9)
As a laminated film, a pressure-sensitive adhesive (trade name: Z2-25, manufactured by Panac Co., Ltd.) is laminated to triacetyl cellulose (trade name: TDP, manufactured by FUJIFILM Corporation, front retardation = 1 nm, film thickness 60 μm). The anti-counterfeiting medium of Production Example 9 was produced in the same manner as in Production Example 1 except that the product was used.

Similarly, the optical films 106, 107, 110-112 were used as the base film (support) of the anti-counterfeit medium.

All of the anti-counterfeit media of Production Examples 1 to 9 had excellent latent image visibility, and the print did not peel off in the tape adhesion test or the scratch resistance test, and the durability was excellent. Therefore, it was found that the optical film of the present invention can be preferably used as a base film (support) for an anti-counterfeiting medium.

INDUSTRIAL APPLICABILITY The present invention can be used for a method for producing a homogeneous acrylic resin film that is highly durable, tough, and does not cause optical disturbance on the surface and inside.

1 Melting kettle 2 Pump 3, 6, 12, 15 Filter 4, 13 Stock tank 5, 14 Liquid feed pump 8, 16 Conduit 10 UV absorber charging kettle 20 Confluence pipe 21 Mixer 30 Die 31 Endless support 32 Web 33 Peeling position 34 Tenter device 35 Roller drying device 36 Conveying roller 37 Winding device 41 Preparation pot 42 Stock tank 43 Pump 44 Filter 100 Main filtration device 102 Extraordinary filtration device 103 Static tank (stock tank)
104 Dope flow pipe (flow pipe)
105 Pump 106 Diluting solvent tank 107 Solvent injection pipe 108 Piping 110 Flowing die 111 Endless support 112 Peeling roll 113 Open / close valve 114 Open / close valve 115 Open / close valve 116 Open / close valve 117 Open / close valve 118 Solvent discharge pipe 119 Solvent reuse return pipe 212 Letter A
213 letter B
214 characters C
215 Background 372 Decanter 381 Crude Hydrophilic Solvent Tank 382 Crude Hydrophobic Solvent Tank 383, 385 Distillation Tower 384 Hydrophilic Solvent Tank 386 Hydrophobic Solvent Tank

Claims (2)

A method for producing an acrylic resin film containing an acrylic resin and rubber particles.
A step of preparing a dope containing an acrylic resin having a glass transition temperature (Tg) in the range of 120 to 180 ° C. and a weight average molecular weight of 300,000 to 4 million and rubber particles having a core-shell structure. ,
A step of filtering the dope using a filter having a filtration accuracy in the range of 5 to 100 μm to prepare the dope, and a step of preparing the dope.
The step of spreading the dope after filtration on the support and peeling off the web,
It has a step of drying the web, and
An acrylic resin having a transmitted maple property C value in the range of 80 to 100% when measured under the condition that a parallel ray is incident on the acrylic resin film at an angle of 75 degrees and the optical comb width is 0.125 mm. How to make a film. The method for producing an acrylic resin film according to claim 1, wherein the content of the rubber particles having a core-shell structure is within 5 to 20% by mass with respect to the acrylic resin film.

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