WO2020149206A1

WO2020149206A1 - Method for producing acrylic resin film

Info

Publication number: WO2020149206A1
Application number: PCT/JP2020/000439
Authority: WO
Inventors: 笠原　健三; 一浩青木; 俊平一色; 昌弘大和田; 友輝川野
Original assignee: コニカミノルタ株式会社
Priority date: 2019-01-15
Filing date: 2020-01-09
Publication date: 2020-07-23
Also published as: JPWO2020149206A1; JP7371641B2; KR20210102384A

Abstract

This method for producing an acrylic resin film produces an acrylic resin film that contains an acrylic resin and rubber particles, and comprises: a step for preparing a dope that contains an acrylic resin which has a glass transition temperature (Tg) within the range of from 120°C to 180°C and a weight average molecular weight of from 300,000 to 4,000,000 and rubber particles which have a core-shell structure; a step for preparing a dope by filtering the above-described dope with use of a filter that has a filtration accuracy within the range of from 5 μm to 100 μm; a step for casting the dope after filtration onto a supporting body and separating a web therefrom; and a step for drying the web. This method for producing an acrylic resin film is also configured such that if parallel light rays are incident on the acrylic resin film at an angle of 75 degrees and a measurement is performed with an optical comb width of 0.125 mm, the C value of transmitted images is within the range of from 80% to 100%.

Description

Method for producing acrylic resin film

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

In recent years, 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 substrate films such as touch panel substrate films and gas barrier substrate films However, there is a great demand for a flexible resin film that realizes high transparency, high functionality and weight reduction, such as a substrate film for a nanoimprint substrate film or a substrate film for a flexible electronic circuit.

Among them, 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 there is an increasing demand for tougher and more durable films, acrylic resins are required to have a high glass transition temperature and a high molecular weight.
By increasing the methyl methacrylate ratio of the acrylic resin to have a high molecular weight, the volatilization amount of the volatile component is controlled by temperature, the heat resistance is excellent, and a technique of suppressing streaks and step unevenness is disclosed (for example, Patent Document 1).

In addition, it is known that the acrylic resin film contains rubber particles dispersedly contained in order to absorb impact and improve strength. The distribution also has an effect on the interaction with the acrylic resin, which causes the dope to have a high viscosity and a local viscosity distribution. By having such a local viscosity distribution, a minute fluidity distribution in solution casting, a leveling distribution, and a hardness distribution of a dry film occur, forming minute irregularities on the film surface, and image clarity (for example, The linearity of the fluorescent light reflected image on the film surface) deteriorates. Further, the rubber particles have a primary particle diameter that is considered not to cause sufficient light scattering, but if there is coarse soft aggregation or coarse/fine distribution, it becomes apparently coarse particles, and In order to exert the effect, not only the unevenness of the surface but also the distribution inside the film causes an optical disorder.
On the other hand, optical films are being applied to 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 were transparency and adhesiveness. Since the demand for wet/dry coating and nano-fine processing have been added, a surface structure without fine irregularities is required.

International Publication No. 2015/063472

The present invention has been made in view of the above problems and circumstances, and a problem to be solved is 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. is there.

In order to solve the above problems, the present inventors set the addition conditions of the rubber particles having a core/shell structure, the filtration accuracy of the dope, and the transmission mappability within a certain range in the process of examining the causes of the above problems. As a result, it has been found that 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, and has reached the present invention.
That is, the above-mentioned subject concerning the present invention is solved by the following means.

1. Acrylic resin, a method for producing an acrylic resin film containing 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 4,000,000 and rubber particles having a core-shell structure; ,
Preparing a dope by filtering the dope with a filter having a filtration accuracy within the range of 5 to 100 μm;
A step of casting the dope after filtration on a support and peeling the web,
And a step of drying the web, and
An acrylic resin having a transmission image clarity C value within a range of 80 to 100% when measured under the condition that a parallel light ray is incident on the acrylic resin film at an angle of 75 degrees and an optical comb width is 0.125 mm. Film manufacturing method.

2. 2. The method for producing an acrylic resin film according to item 1, wherein the content of the rubber particles having the core/shell structure is within the range of 5 to 20 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 highly durable, tough and homogeneous acrylic resin film that does not cause optical disturbance on the surface and inside.

The mechanism of action or mechanism of action of the present invention has not been clarified, but is presumed 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 image clarity is improved. By controlling the viscosity within the specified range, the viscosity of the dope is controlled to an appropriate state, and the local viscosity distribution at the location in the dope is reduced and homogenized, so the minute fluidity distribution and leveling distribution in solution casting are obtained. Therefore, the hardness distribution of the dry coating is reduced, and it is presumed that the problem of the present invention has been solved.

The schematic diagram of the manufacturing apparatus used for the manufacturing method of the acrylic resin film of this 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 film between the casting film and the endless support Schematic plan view schematically showing an example of a tenter stretching device 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 a tenter clip used in the present invention Schematic diagram for explaining oblique stretching used in the method for producing an acrylic resin film of the present invention Schematic view of a stretching apparatus according to an embodiment of the present invention Side view showing the outline of the winding device The top view which shows the outline of a winding device. Explanatory drawing which shows the relationship between the welded part of a band, and the formation area on the welded part of a film, (A) is a top view which shows the relationship between the welded part of a band, and a casting film, (B) is a top view of a film. Schematic diagram from the drying process to the winding process Explanatory drawing showing the static elimination method using a ventilation type static eliminator Perspective view showing acrylic resin film and packaging material Perspective view showing an embodiment of a package Explanatory drawing of the operation of this embodiment Perspective view showing how the film tip is attached to the winding core The top view which shows the attachment state of the film front end to a winding core. Sectional view of film wound 3 times around the end of film Sectional drawing of 2nd Embodiment Sectional drawing of 3rd Embodiment Sectional drawing of the film winding state of the embodiment Sectional drawing of 4th Embodiment FIG. 4 is a plan view showing how the film tip is attached to the winding core in another embodiment in which the inclination angle of the film tip is changed. Schematic diagram for explaining a method for 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 on both ends of the film and wound it up. Diagram showing the surface and cross section of the tape that has been embossed or slitted (A) is a schematic schematic view of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a perspective view of a vertical cross section of the film of (A) in the width direction, and (C) is Schematic schematic diagram for explaining the embossed region in the film of (A) (A) is a schematic schematic view of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a perspective view of a vertical cross section of the film of (A) in the width direction, and (C) is Schematic schematic diagram for explaining the embossed region in the film of (A) (A) is a schematic schematic view of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a perspective view of a vertical cross section of the film of (A) in the width direction, and (C) is Schematic schematic diagram for explaining the embossed region in the film of (A) (A) is a schematic schematic view of an example of an embossed region that the acrylic resin film of the present invention may have, (B) is a perspective view of a vertical cross section of the film of (A) in the width direction, and (C) is Schematic schematic diagram for explaining the embossed region in the film of (A) Schematic of film production line Top view of winding device A graph showing the relationship between the film stress and the winding length in the circumferential direction of the winding core. Explanatory drawing of the stress of the film in the circumferential direction of the winding core Graph showing the relationship between surface pressure and winding length when wound by straight winding Graph showing the relationship between surface pressure and winding length when wound with oscillate winding Flow chart showing the operation of the winding device Schematic diagram showing an example of film production 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 manufacture of the forgery prevention medium A Enlarged view of pattern observed on anti-counterfeit medium A through a polarizing plate The figure which shows the photomask used by the pattern exposure at the time of manufacture of the forgery prevention medium B. The figure which shows the pattern of the slow axis of the forgery prevention 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, wherein the glass transition temperature (Tg) is in the range of 120 to 180° C., and the weight average is A step of preparing a dope containing an acrylic resin having a molecular weight of 300,000 to 4,000,000 and rubber particles having a core-shell structure, and filtering the dope with a filter having a filtration accuracy of 5 to 100 μm. A step of preparing a dope, a step of casting the filtered dope on a support to peel off the web, and a step of drying the web, and 75° with respect to the acrylic resin film. It is characterized in that the transmission image clarity C value is in the range of 80 to 100% when measured under the condition that a parallel light beam is incident at an angle of, and the optical comb width is 0.125 mm.
This feature is a technical feature common to each of the following embodiments.

In 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 based on the acrylic resin film from the viewpoint of manifesting the effects of the present invention.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described. In the present application, “to” 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 the method for producing an 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, wherein the glass transition temperature (Tg) is in the range of 120 to 180° C., and the weight average is A step of preparing a dope containing an acrylic resin having a molecular weight of 300,000 to 4,000,000 and rubber particles having a core-shell structure, and filtering the dope with a filter having a filtration accuracy of 5 to 100 μm. A step of preparing a dope, a step of casting the filtered dope on a support to peel off the web, and a step of drying the web, and 75° with respect to the acrylic resin film. It is characterized in that the transmission image clarity C value is in the range of 80 to 100% when measured under the condition that a parallel light beam is incident at an angle of, and the optical comb width is 0.125 mm.

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 image clarity are set within the above-mentioned ranges. The viscosity of the solution is controlled to an appropriate state, and the local viscosity distribution at the location in the dope can be reduced and homogenized, resulting in a fine fluidity distribution during solution casting, a leveling distribution, and a dry film hardness. It is possible to provide a method for producing a uniform acrylic resin film with reduced distribution, high durability, toughness, and no optical disorder 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 be suitably used. Particularly preferred is a matting agent used as an anti-blocking agent for the film. Fine particles used as a matting agent include inorganic fine particles and organic fine particles. Acrylic-based materials are preferably used as the 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 have a glass transition temperature of room temperature, that is, 25° C. or less. .. When the glass transition temperature is higher than 25°C, it is not suitable as the rubber particle of the present invention.

<Transparency>
The transmission image clarity according to the present invention is measured using an image clarity measuring instrument (for example, image clarity measuring instrument ICM-1T manufactured by Suga Test Instruments Co., Ltd.). It is assumed that parallel light rays are 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. In addition, by moving the optical comb orthogonal to the optical axis of the transmitted light of the test piece, the light amount (M) when the comb transmitting portion is on the optical axis and the light amount (m) when the comb light shielding portion is present on the optical axis are obtained. The ratio (C value (%)) of the difference (M−m) between the two and the sum (M+m) is a measure of the image definition.
The C value is preferably 80% or more, and particularly preferably 90% or more.

[Acrylic resin film manufacturing apparatus 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 acrylic resin film manufacturing apparatus is not particularly limited, and a general solution casting method film forming apparatus can be used.

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

The acrylic resin is dissolved in an appropriate amount of organic solvent in the charging pot 41, and is sent to the filter 44 to remove large aggregates, and then sent to the stock tank 42. Then, 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 dissolving pot 1 to prepare the main dope.

As an additive, a plasticizer, a matting agent, an ultraviolet absorber, etc. are appropriately added to the charging pot 41 after being stirred and diluted with a solvent in an additive charging pot to make an additive liquid.

The main dope is cast from the die 30 onto the endless support 31, peeled 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 number of transport rollers 36 in a roller drying device 35, and wound by a winding device 37.

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

Further, JP-A-2000-301555, JP-A-2000-301558, JP-A-7-032391, JP-A-3-193316, JP-A-5-086122, and JP-A-62-037113. The techniques for forming a cellulose acylate film described in JP-A-2-276607, JP-A-55-014201, JP-A-2-111511, and JP-A-2-208650 are used. 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 4,000,000, 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 with a filter having a filtration accuracy of 5 to 100 μm, and the dope after the filtration is cast on a support to peel the web. And a step of drying the web.

Detailed description of each process. Hereinafter, the “acrylic resin film” may be simply referred to as a “film”.

(0) Raw Material Storage/Supply Step In the manufacturing process of the acrylic resin film according to the present invention, the raw material is stored in a packaging form in which it is distributed/supplied, a step of unpacking and storing in a silo or a tank, It is preferable to further include a step of transferring to another silo or tank.
The packaging form at the time of distribution and supply of the raw materials is not particularly limited, such as a paper bag, a flexible container bag, a container, and a tank truck, but a packaging form that shields temperature, humidity, ultraviolet rays, and oxygen during storage is particularly preferable.
Acrylic resin has a relatively low glass transition temperature as compared with other resins, and thus tends to cause blocking. Regarding storage environmental conditions, it is preferable that the storage temperature is low, the humidity is low, and the load is low. Therefore, it is not preferable to use a silo having a larger capacity than necessary. In a low-humidity environment, there is a risk of dust explosion, and grounding of the storage container/transfer pipe and, if necessary, replacement with an inert gas are also preferably performed.
The acrylic resin as a raw material has a variation in the weight average molecular weight due to a lot variation during manufacturing (synthesis). In order to prevent the viscosity of the dope from changing when the lots are switched, it is preferable to store a large number of lots in separate storage containers and blend the lots so that the weight average molecular weights are leveled. By storing different lots in at least two silos and supplying the lot blend amounts of one and the other to the next step with gradation, it is possible to avoid a rapid change in the dope viscosity.
The raw material of the acrylic resin film according to the present invention includes self-returning material. It is preferable that the returned material should be in the same storage condition as other raw materials. Recycled material is usually flaky film fragments, and blocking is likely to occur, so caution is required.
The method for transferring the raw materials is not particularly limited, such as transfer by free fall, pneumatic transfer in a 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 perform static elimination/grounding to reduce triboelectrification, or to increase the filling rate of raw materials in the pipe or replace with an inert gas to reduce oxygen concentration. In particular, since the returned material does not have good fluidity, a screw feeder capable of forced discharge is preferable.
The weighing at the time of transfer may be managed by rotation of the feeder, but a load cell method for measuring the weight of the receiving container is preferable.

(1) Dope preparation process (dissolution process)
In an organic solvent mainly composed of a good solvent for an acrylic resin, the acrylic resin in a dissolution pot, and in some cases, a plasticizer or various function expressing agents (for example, an antioxidant, a light stabilizer, an ultraviolet absorber, a retardation adjusting agent). , A peeling accelerator, an infrared absorbing agent, a matting agent, etc.) while stirring to form a dope, or by mixing the acrylic resin solution with a solution of the plasticizer and various function expressing agents. This is a step of preparing a dope which is a solution.
In the present invention, a dope containing an acrylic resin having a glass transition temperature (Tg) 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. Is prepared.

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 can dissolve the acrylic resin and other compounds at the same time.

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, 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. When the proportion of alcohol in the dope is high, the web is gelled, which facilitates peeling from the metal endless support.When the proportion of alcohol is low, cyclic polyolefin and other polyolefins in a non-chlorine organic solvent system are used. It also has the role of promoting dissolution of the compound. In the film formation of the acrylic resin film according to the present invention, from the viewpoint of enhancing the flatness of the resulting acrylic resin film, the film is formed using a dope having an alcohol concentration in the range of 0.5 to 15.0% by mass. The method can be applied.

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

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. Of these, methanol and ethanol are preferable because the dope is stable, the boiling point is relatively low, and the drying property is good.

In order to dissolve the acrylic resin, the plasticizer, and the function expressing agent, a method under normal pressure, a method under the boiling point of the main solvent, a method under pressurization over the boiling point of the main solvent, JP-A-9-95544, Use of various melting methods such as the method of cooling and melting as described in Kaihei 9-95557 or Japanese Patent Laid-Open No. 9-95538, and the method of high pressure described in Japanese Patent Laid-Open No. 11-21379. However, it is particularly preferable to apply pressure at a temperature not lower than the boiling point of the main solvent.

Further, it is preferable to use the mixing device shown in FIG. 5 of JP 2011-143360 A for acrylic resin and additives. 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 one or more branch pipes into which the liquid is injected, and a branch pipe connected to the branch pipe. In the projection view from the main pipe axial direction, the liquid moving direction in the branch pipe is the main pipe radial direction from the communicating position with the branch pipe in the main pipe axial direction. The branch pipes are arranged so as to have an inclination angle therebetween. Introducing from a solid material introducing pipe having such a branch pipe is preferable from the viewpoint of reducing foreign matters.

Specifically, a solution of additives such as a plasticizer, an ultraviolet absorber, a matting agent, and an antioxidant is independently added, preferably from the solid material introducing pipe 5 shown in FIG. Is dissolved or dispersed in the dope to form a dope.

The type of pressure vessel used to dissolve 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 to the pressure vessel, other instruments such as a pressure gauge and a thermometer are appropriately arranged. Pressurization may be carried out by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

The heating temperature with the addition of the solvent is not less than the boiling point of the solvent used, and in the case of a mixed solvent of two or more kinds, the heating temperature is not lower than the boiling point of the solvent having the lower boiling point and the solvent does not boil. Is preferred. If the heating temperature is too high, the required pressure will increase and the productivity will deteriorate. The preferable heating temperature range is 20 to 120° C., more preferably 30 to 100° C., and further preferably 40 to 80° C. The pressure is adjusted so that the solvent does not boil at the set temperature.
The order of transferring the raw materials to the melting pot and adding them is preferably such that the powder raw materials, especially the acrylic resin, are added while a certain amount of the organic solvent is in the melting pot. Further, if all the raw materials are charged all at once, the raw materials having a low specific gravity gather near the liquid surface to generate sprouts, and the melting time becomes long. It is preferable to adjust the charging rate to be 1 to 10%/min.
When the powder is added to the charging port, the powder may adhere to each other to form a lump by contact with the vapor of the organic solvent. For this reason, it is preferable to vent during the addition so that the vapor of the organic solvent is guided to another place. In addition, it is also preferable to perform Teflon (registered trademark) inner surface processing so that the solidified product does not adhere to the charging port.
When an organic solvent having a large specific gravity (for example, methylene chloride, etc.) is used, the acrylic resin tends not to reach the lower part of the pot due to the difference in specific gravity from the resin, and the organic solvent tends to become rich. In order to ensure the uniformity of the dope, it is preferable that the shape of the melting pot is designed so that there is no dead portion, or that the stirring is designed so that convection also flows into the dead portion.

In the apparatus for preparing an acrylic resin dope according to the present invention, it is preferable that the apparatus 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. .. To be connected via a circulation path means that there is a circulation path between the storage tank and the heat exchanger, and that there is a circulation path between the heat exchanger and the storage tank. The circulation path may be capable of heat exchange, and in some cases, the circulation path also serves as a heat exchanger. The dope may be returned from the dope outlet of the storage tank to 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 having a circulation path may be connected. In this case, additional solvent may be added to the second storage tank. The circulation path has the function of effectively shortening the dissolution time, and also has the ability of complete dissolution. Generally, in a dissolution container provided with a circulator, it takes too much time to attain a dissolved state because it is simply circulated. On the other hand, in a heat exchanger in which heat is applied to the solution for a short time, gel is likely to be generated in the dope, and the time is too short for complete dissolution.

The storage tank used in the present invention is preferably a pressure vessel having a jacket inside or outside the tank and having an agitator 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 occur on the gas-liquid interface of the dope and the wall surface of the storage tank, and a film failure due to the outflow of the dope 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 mist into the storage tank and control it so that it operates sufficiently and sufficiently against the saturated vapor pressure.

In the process of mixing and dissolving the acrylic resin and the solvent, it is preferable to apply a shearing force of 9.8 to 9.8×10 ⁵ N and stir. Stirring within the range of the shearing force described above allows powder agglomerates to be formed shortly, and even if it is formed, the powder agglomerates can be crushed and dissolved. When the shearing force is less than 9.8 N, the stirring force is weak and the dispersion efficiency is poor, and the dispersion exceeding 9.8×10 ⁵ N becomes too fine, clogging occurs in the subsequent filtration step, and the filtration efficiency is significantly reduced. I will let you. The shearing 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 and cooled with a heat exchanger and the obtained polymer dope is used for film formation. May be cooled to room temperature.

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

(Moisture content)
Further, in the dope preparation step, the water content is 2.0 to 5.0 mass% at the start-up from the production start to the steady operation, and the water content is 0.1 to 2.0 mass% at the steady operation. It is preferable to adjust as described above from the viewpoint of the stability of the dope and the transparency of the film.

As a method of setting the water content at the time of start-up within the range of 0.6 to 2.0 mass% with respect to the total amount of the dope, 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. There is a method in which the ratio is calculated, and the shortage is mixed with a solvent and then mixed as a dope.

Since the line speed is slow at the start-up, if the water content is less than 2.0 mass% with respect to the total amount of the dope, the web is likely to peel off from the endless support before peeling. If the film peels off, it will have to be restarted, and productivity will deteriorate. On the other hand, when the water content is more than 5.0% by mass, the solubility of the acrylic resin in the solvent is deteriorated and the endless support is apt to be soiled.

As a means for lowering the water content of the dope within the range of 0.6 to 2.0 mass% from the start-up to the steady operation, it is adjusted by in-line addition of the predetermined acrylic resin and other additives. That is, the water content in the dope is calculated from the sum 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 through the line. Are listed.

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

Also, when fine particles are added to the acrylic resin dissolution step, it is preferable that the dissolution and mixing be performed at a temperature of not less than the boiling point of the main solvent and not more than the same boiling point +50°C. In this way, by defining the temperature of the fine particles to be dissolved and mixed in the acrylic resin dissolving step at a temperature not higher than the boiling point of the main solvent +50° C., the foreign matter generation rate can be reliably suppressed in the dope dissolving and mixing step.

Also, it is preferable that the fine particles are dissolved and mixed in the acrylic resin dissolving step for a time in the range of 30 to 300 minutes. By thus defining the time for dissolving and mixing the fine particles in the acrylic resin dissolving step, the variation coefficient (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 acrylic resin dissolution step during the addition of the acrylic resin to the dissolution tank or after the addition of the particles before the acrylic resin is completely dissolved in the dissolution tank. In this way, by defining the timing of addition of fine particles in the acrylic resin dissolution step, the foreign matter generation rate due to the addition of fine particles contained in the acrylic resin solution (dope) can be ensured in the dope dissolution and mixing step. It can be suppressed, the load on the filter in the subsequent filtration step is significantly 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 fine particle dispersion is prepared in advance, and this fine particle dispersion is added in the step of dissolving the acrylic resin in the main solvent, and after the addition, at a temperature not lower than the boiling point of the main solvent. It is preferable to dissolve and mix.

As the solvent used for dispersing the fine particles, the organic solvent used for forming the acrylic resin film can be used. Alcohols are particularly preferable, and examples thereof include those having 1 to 8 carbon atoms such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol and tert-butanol.

When the fine particles are mixed with a solvent and dispersed, the concentration of the fine particles 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 more the liquid turbidity tends to be low with respect to the added amount, and the haze and the aggregates are improved, which is preferable.

When the fine particles are mixed and dispersed with a solvent and a small amount of resin, the concentration of the fine particles 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 fine particles is excellent. Note that the smaller the content of the fine particles, the lower the viscosity and the easier handling, and the larger the content of the fine particles, the smaller the addition amount and the easier the addition to the main dope. Therefore, the above range is preferable.

A normal disperser can be used as the disperser for dispersing the fine particles. Dispersers are roughly classified into media dispersers and medialess dispersers. For dispersing fine particles, a medialess disperser is preferable because of low haze.

Examples of the media disperser include a ball mill, a sand mill and a dyno mill. As the medialess disperser, there are an ultrasonic type, a centrifugal type, a high pressure type, and the like. In the present invention, a high pressure dispersing device is preferable. The high-pressure dispersing device is a device that creates special conditions such as high shear and high-pressure state by passing a composition obtained by mixing fine particles and a solvent at high speed through a thin tube. It is preferable that the maximum pressure condition inside the apparatus is 9.8×10 ² N or more in a thin tube having a tube diameter of 1 to 2000 μm by processing with a high-pressure dispersion apparatus. More preferably, it is 1.96×10 ³ N or more. At that time, it is preferable that the maximum reaching speed is 100 m/sec or more and the heat transfer speed is 100 kcal/hr or more.

The high-pressure disperser as described above includes an ultrahigh-pressure homogenizer manufactured by Microfluidics Corporation (2 brand name: Microfluidizer) or Nanomizer manufactured by Nanomizer, or Ultra Turrax. Examples include Food Machinery homogenizer, Sanwa Machinery Co., Ltd., product number UHN-01.
It is also preferable to dispose a dispersion blade that gives high shear in the dissolution bath and disperse the dispersion in the dope dissolution bath so as to further control the dispersion state of the added dispersion liquid.

For example, the content of silica (Si) in the fine particles contained in the acrylic resin film is determined by subjecting the absolutely dried acrylic resin film to pretreatment with a micro digest wet decomposition apparatus (sulfuric acid/nitric acid decomposition) and alkali melting, and then ICP-AES (Inductively coupled plasma optical emission spectroscopy analyzer) can be used for analysis.

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 content ratio of the fine particle dispersion is dissolved in the dissolving step. It is preferably 0.1 to 0.5 times the solid content ratio of the acrylic resin solution (dope).

In this way, it is preferable that the fine particle dispersion liquid contains the acrylic resin in addition to the fine particles, since the viscosity of the dispersion liquid is adjusted and the stagnation stability is excellent.

Further, in order to carry out co-casting, it is also preferable to use an apparatus capable of simultaneously preparing a plurality of types of dope as shown in FIG. 2 of JP-A-2009-072963. In FIG. 2 of the publication, the raw material dope 11 is fed by the liquid feeding pumps P3, P4, P5 through the three

dope channels

33, 34, 35 for the intermediate layer, the support surface, and the air surface. .. Then, in the intermediate layer dope channel 33, 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 13 are added by the in-line mixer 39 and the shear mixer 43. 13 and 13 are mixed with each other to form the intermediate layer dope 16. Similarly, in the support surface dope flow path 34, 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 support surface dope 17, and the air surface dope flow path. 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 air surface dope 18. If necessary, a diluent for adjusting the TAC concentration of the dope may be added to the

dope channels

34 and 35 for the support surface and the air surface.

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

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

In the present invention, the 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 of the main solvent at 1 atm. 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 filtration of the dope, the method for producing an optical film described in JP 2012-56103 A is also preferably used.

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

Although there are several methods for filtering, a filter press or a disc filter is suitable for filtering the acrylic resin dope, and in particular, the filter pressing method has a high productivity because the filtering area can be wide. Suitable from a point of view.
FIG. 2 shows an example of the flow of filtration.
As shown in FIG. 2, a solution (dope) in which an acrylic resin is dissolved is temporarily stored in a stationary tank (stock tank) 103 from a melting pot (not shown). A pump 105 and an opening/closing valve 113 are provided on the way of the dope flow pipe 104 from the stationary tank 103 to the main filtration device 100, and a solvent injection pipe from the dilution solvent tank 106 is provided downstream of the opening/closing valve 113. 107 is connected. An opening/closing valve 115 is interposed in the dope flow pipe 104 on the outlet side of the main filtration device 100.

When initially filling the main filtration device 100 with the dope, the opening/closing valve 113 on the way of the dope flow pipe 104 is opened, and the opening/closing valve 115 on the outlet side of the main filtration device 100 on the way of the dope flow pipe 104 is closed. For the dope of acrylic resin having a viscosity of, for example, 10 to 50 Pa·s sent from the stationary tank 103 by the operation of the pump 105, the opening/closing valve 114 of the solvent injection pipe 107 is opened to dilute. The solvent is injected from the solvent tank 106 for use in casting, and the dope having a predetermined high viscosity for casting is diluted with the solvent to reduce the viscosity to, for example, 1 to 9 Pa·s. By injecting into 100 and performing initial filling, air in the main filtration device 100 and bubbles inside the filter medium (not shown) are expelled. When the dope having a reduced viscosity is injected into the main filtration device 100 as described above, the low-viscosity dope is easily permeated into the filter medium and can spread to every corner of the filter medium to 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 dilution solvent tank 106. Then, when the air inside the main filtration device 100 and the bubbles inside 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 and closing the on-off valve 115 on the way of the dope flow pipe 104 on the outlet side of the main filtration device 100, the main filtration device 100 including the filter medium in which the initial filling is completed and the bubbles are expelled is used, and the stationary tank is used. The dope having a predetermined high viscosity for casting, which is sent from the 103 through the pump 105 by the operation of the pump 105, is passed through the main filtration device 100 and then supplied from the sending pipe 104 to the casting die 110. The dope is cast from the feed pipe 104 onto the endless support 111 to perform casting 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 aggregates such as fine particles that cause foreign matter can be removed and the high-viscosity main dope can be continuously filtered. The film can be formed and the productivity is improved.

The filter of the present invention used in 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 coagulation or high-viscosity components are forced to pass through, making filtration impossible. If the dope is cast in the state of coagulation or a locally high-viscosity component, non-uniformity of the cast film based on the local viscosity distribution is brought about, which is not preferable. Of course, since coarse foreign matters cannot be removed by low-precision filtration larger than 100 μm, this is also not preferable. It is presumed that the coagulation or high-viscosity component in the dope is appropriately divided and dispersed by setting the filtration accuracy in an appropriate range, the local viscosity distribution is eliminated, and eventually a finely uniform film can 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 particles. That is, theoretically, a filtration accuracy of 5 μm means that 99.9% of monodisperse particles of 5 μm are collected and less than 99.9% of monodisperse particles of less than 5 μm are collected, and monodisperse particles of more than 5 μm are collected. However, the collection rate is higher than 99.9%. However, it is a value having a certain width practically, and a filter of 4.5 μm in actual measurement of filtration accuracy is also nominally called 5 μm. In the present invention, a value rounded to the nearest 1 μm is adopted.
The filter of the present invention preferably has a multi-stage structure. In that case, the filter that obtains the effect of the present invention refers to the filter with the highest precision (the lowest numerical value of filtration precision).

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 at less than 10 sec/100 ml, the strength of the filter medium such as the filter paper is weak, and the filter paper opens due to the pressure, increasing foreign matter failure. Further, when the drainage time of the filter medium becomes longer than 25 sec/100 ml, the initial pressure becomes high, the filtration resistance becomes too high, and high flow rate filtration cannot be continuously carried out. Therefore, the filter life becomes short. Therefore, it is not preferable. The filtration time is measured according to JIS P 3801, and a Hertzberg filtration rate tester is used, and 20 ml of distilled water at 20° C. and a pressure of 0.98 kPa are applied on a filtration surface of 10 cm ^2. It means the time for filtering.

The particle size of the filter paper and the drainage time of the filter paper of the main filtration device 100 are selected by the fiber thickness of the filter paper, the selection of the fiber material such as the material (cotton linter, wood pulp, rayon, polyester fiber, etc.) and the beating machine. The beating degree, the addition of filler, and the like can be arbitrarily adjusted by the method for producing the filter paper.

In the present invention, even a single filter paper of the main filtration device 100 is effective, but it is more preferable to use two to seven filter papers in piles because the filtration efficiency becomes high. The same filter paper may be combined, or a filter paper having a small retained 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 filter paper such as soft cotton can remove large dust without affecting the filtration pressure, and can prevent liquid leakage of the main filtration device 100, which is preferable. Two-stage filtration in which the main dope that has been filtered once is filtered again is also preferable because it has a large effect of removing aggregates.

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

The filtration filters used in the filtration process can be broadly classified into two types, surface type and depth type, depending on the media structure. The surface type is a type in which the media passing through the substance to be filtered has a short distance, and the size of particles that can be removed is determined by the opening of the surface. In the present invention, the surface-type filter is used for a long time, gel-like aggregates contact each other on the surface, grow into larger aggregates, and pass through the filter due to a pressure increase, so the aggregates cannot be removed and increase. I have a concern that

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

On the other hand, the depth type filter is also called deep layer filtration or volumetric filtration, and has a certain amount of media thickness. This type of filter has a lower possibility of agglomerates contacting each other in the filter part than the surface type, it is difficult to generate large gel-like agglomerates, pressure rise is small even when used for a long time, and gel It is preferable because the granular aggregate can be removed.

As the depth type, for example, Advantech Toyo Co., Ltd. wind cartridge filter TCW type, depth cartridge filter TCPD type, Nippon Seisen Co., Ltd. fine pore NF series, etc. can be mentioned.

It is preferable that the additive liquids added in-line are filtered with at least two types of depth filters having different pore diameters because it is possible to effectively filter various aggregates having different sizes. Less preferred.

These filters are filters having a particle collection rate of 5 to 10 μm of 20 to 60% when 8 kinds of 0.5 ppm aqueous dispersions of the test powder 1 specified in JIS Z 8901 are filtered. Preferably, the additive liquid is added in-line after being filtered with these filters. The particle collection rate is more preferably 30 to 50%. It is preferable that the particle collection rate is small so that the aggregation does not grow, and that the particle collection rate is large is preferable in that the aggregation is removed. As the particle collection rate of 20 to 60%, for example, Advantech Toyo Co., Ltd. wind cartridge filters TCW-1N, 3N, 5N, 10N, 25N, 50N, pleated cartridge filter TCPE-10, 30 etc. Are listed. 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. In addition, after filtering a filter having a particle collection rate of 20 to 60% with a filter having a small particle collection rate, further filtering with a filter having a large particle collection rate removes the aggregation without causing the aggregation to grow. Is most preferable. The particle collection rate is defined as follows.

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

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

　The filter is divided into a membrane type and a bobbin type depending on the filter material structure. The membrane type is a type that has 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 From the core to the core, a filter of the membrane type and depth type can be obtained by making several filter media in which the size of the holes of the filter media is gradually reduced to a certain thickness (10 to 20 mm).

As the membrane type, for example, a membrane cartridge filter TCF type manufactured by Advantech Toyo Co., Ltd., a pleated cartridge filter TCPE type and the like can be mentioned.

The wound type uses endless fibers with a certain gap in the filter medium without twisting long fibers such as polypropylene, and winds it around the core at a constant density. If it is wound without winding, it becomes a surface type, and if it is made finer in the core direction such as changing the voids of the filter medium or giving a density gradient, it becomes a depth type filter. Examples of the thread winding type include a wind cartridge filter TCW type manufactured by Advantech Toyo Co., Ltd. (a core is a hollow core around which a filter material thread or a membrane is wound).

When the acrylic resin film of the present invention is produced, the main dope may be cast as it is, but various additives may be added in-line to the main dope and mixed and cast depending on the purpose. Since the coagulation contained in the in-line additive liquid is a gel form of secondary and tertiary coagulation, the coagulation (material) is likely to come off in the membrane type filter medium, and the wound type has a better cohesive force of the coagulation (material). preferable.

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

Further, it is preferable that the filter material of the filter is polypropylene from the viewpoint of solvent resistance. The core material of the filter is preferably polypropylene or stainless steel, and more preferably stainless steel. Stainless steel is preferred because the core does not easily swell with the solvent even after long-term use and aggregates do not come out from the tightening part. After filtering the additive solution using these filters, the additive is added inline to the main dope. It is preferable. The effect of removing the agglomerates is improved by providing the filter with a certain number of times. However, if the amount is too large, the effect is reduced relative to the number of steps, 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 with a metal filter having an absolute filtration accuracy of 30 to 60 μm immediately before mixing the additive liquid with the main dope with the in-line mixer (in the step immediately before). Immediately before means, in terms of process, that there is a filtration step immediately before, and from the flow, immediately after filtration, there is no stagnation of the added liquid, for example, a stock tank or liquid feed pump. It means that it is sent to the in-line mixer without going through it and mixed with the main dope. As a result, it is preferable that the liquid does not become stagnant and a new agglomerate is not generated by the liquid feed pump. These filters are placed immediately before the in-line mixer, and for example, large aggregates generated from the route due to filter replacement etc. are reliably filtered from the additive liquid being fed, and relatively large foreign substances can be reliably removed by one filtration. Among these filters, a metal filter having solvent resistance and capable of being used for a long period of time and having the above-mentioned absolute filtration accuracy is preferable. The metal is preferably stainless steel from the viewpoint of durability. Also, unlike the depth type filters described above, it is preferable that these filters are not replaced very often after installation, and therefore, they have a porosity of ε=60 to 80% from the viewpoint of clogging. preferable.

Therefore, it is most preferable for the in-line additive liquid to be filtered with a metal filter having an absolute filtration accuracy of 30 to 60 μm and a porosity ε=60 to 80%, which ensures long-term reliability. It is preferable because coarse foreign substances can be surely removed. Examples of a metal filter having an absolute filtration accuracy of 30 to 60 μm and a porosity ε=60 to 80% include, for example, Finepore NF series NF-10, NF-12, and NF- of Nippon Seisen Co., Ltd. 13 and the like.

The filter provided immediately before in-line addition is preferably a metal filter with an absolute filtration accuracy of 30 to 60 μm, more preferably 40 to 50 μm. It is preferable that the absolute filtration accuracy is small because the ability to remove agglomerates is excellent, and the larger absolute filtration accuracy is that the increase in differential pressure is small even after long-term use, the frequency of filter replacement can be reduced, and productivity is excellent.

(3) Casting Step As shown in FIG. 1, a metal endless support 31 for sending the dope to a pressure die 30 through a liquid feed pump (for example, a pressurization type quantitative gear pump) and transferring it indefinitely. For example, it is a step of casting the dope from a pressure die slit at a casting position on an endless support such as a stainless 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 flow rate fluctuation.

(Casting)
As a method for casting a solution, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal endless support, and a dope once cast onto a metal endless support is used to form a film thickness with a blade. Although there is a method using a doctor blade for adjustment or a method using a reverse roll coater for adjusting with a counter-rotating roll, 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. Further, in addition to the method mentioned here, it can be carried out by various methods of casting film formation of conventionally known cellulose triacetate resin, and each condition should be set in consideration of the difference in boiling point of the solvent used. As a result, the same effects as those described in the respective publications can be obtained. The endless metal endless support used for manufacturing the acrylic resin film according to the present invention includes a drum whose surface is mirror-finished by chrome plating and a stainless belt (band which is mirror-finished by surface polishing). Can be said) is used.

The metallic endless support has a surface energy of the surface of the endless support which is in contact with both widthwise end portions of the dope casting film, and the surface of the endless support which is in contact with the widthwise central portion of the dope casting film. It is preferable to perform activation treatment on the surface of the endless support so that the surface energy is higher than the surface energy of the ear from the viewpoint of suppressing fluttering of the ears.

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

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

Further, the endless support in which a hydrophobizing layer having a water contact angle of 90° or more is formed in the casting film forming area on the endless support is used, and the casting film is formed on the hydrophobizing layer. It is preferably formed. The hydrophobized layer is made of a hydrophobic substance, the endless support is made of a cooling drum, and the casting film is peeled off by self-supporting property 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, the surface of the metal endless support is coated with iron. A metal endless support containing an element of (Fe) and/or chromium (Cr) and having a component element composition ratio on the surface of the metal endless support satisfying the following relationship (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 is because a metal oxide film layer with a higher oxygen bond ratio than the oxide state of a normal metal surface is created while maintaining a very smooth surface state, and even during continuous production of the film, the metal It is possible to manufacture an acrylic resin film having improved optical releasability (peelability) from an endless support made of glass, excellent releasability, and excellent optical properties with excellent transparency and flatness. it can. Furthermore, it is possible to prevent the corrosion of the surface of the metal endless support, eliminate the quality failure such as unevenness that the corrosion pattern is transferred to the film, and when the surface becomes rough due to corrosion, The anchor effect prevents the releasability (peelability) of the web from significantly deteriorating.

If the (Fe ₂ O ₃ +FeO)/Fe ratio of (i) is less than 5, the corrosion resistance is not so different from that of the untreated one, and the difference in the treatment is partly large. It is not preferable because it becomes uneven as the corrosion progresses. Further, when the (Fe ₂ O ₃ +FeO)/Fe ratio exceeds 50, when something touches the surface and scratches the surface, it becomes difficult to perform polishing to restore a smooth surface. Therefore, it is not preferable.

When the (CrO ₂ +CrO ₃ )/Cr ratio of (ii) is less than 10, the corrosion resistance is not so different from that of the untreated one, and the difference in the treatment is partly large. It is not preferable because it becomes uneven as the corrosion progresses. Further, if the (CrO ₂ +CrO ₃ )/Cr ratio exceeds 50, it becomes difficult to polish and restore a smooth surface when something touches the surface and scratches it. Therefore, it is not preferable.

Further, even if the film forming speed is increased, the occurrence of the air entrainment phenomenon is prevented, and the adhesion between the cast film and the endless support is adjusted appropriately, so that the cast film can be separated from the endless support. In order to improve the, when casting the dope on the endless support, a liquid containing at least one organic compound contained in the dope is supplied between the endless support and the casting film to form a casting film. It is also preferable to form an intervening film with the endless support.

As shown in FIG. 3, an intervening film forming device 140 is provided in the vicinity of the casting die 130, and is interposed on the surface of the casting bead 161 which is the 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) that stores the intervening film forming liquid 162, a flow path 140a for this liquid, and a supply port 140b. At the time of casting the dope 160, an appropriate amount of intervening film forming liquid 162 is supplied from the supply port 140b so as to extend 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 casting bead 161 can be further prevented. When the casting beads 161 and the intervening film forming liquid 162 reach the casting drum 150, the casting film 170 is formed on the casting drum 150 via the interposition film 163. Thus, 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 raw material solvent and a poor solvent which is not compatible with the polymer contained in the dope 160. It is preferable to prepare it. The intervening film 163 formed between the casting drum 150 and the casting film 170 by such an intervening film forming liquid 162 diffuses toward the casting film 170 over time. Accordingly, 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 from the casting drum even with a small peeling stress.

Further, when the ratio of the solvent contained in the intervening film forming liquid 162 is w (%) and the film thickness of the intervening film 163 is t (μm) regardless of the good solvent or the poor solvent, w and t are t It is preferable to satisfy <-0.05w+15. This makes it possible to form the intervening film 163 that acts so as to easily peel off the casting film 170 from the casting drum 150. However, if the intervening film 163 is too thick, the casting film 170 and the intervening film 163 are less likely to diffuse, and the intervening film 163 may remain on the casting drum 150. If the intervening film 163 remains on the casting drum 150 in this way, it also adversely affects the subsequent casting and is not suitable because only a film having a poor surface condition can be produced.

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 rate of the film, it eliminates foaming caused by entrainment of entrained air, reduces film thickness unevenness due to vibration of the casting liquid film from the casting die due to decompression chamber suction air, and dissolves the scale that is dripped. In order to obtain a film with excellent flatness without transfer failure due to droplet scattering of the excess liquid of the liquid, the dope is cast on a metal endless support, and a casting film (web) is applied on the endless support. ) Is formed, a downward pressure chamber is provided as a means for reducing the pressure from the casting upstream side so that the web is formed in close contact with the endless support, and when the dope is flowed down from the casting die. In order to prevent the formation of a whisker-like film (scale) on both left and right ends (casting die edge) corresponding to both ends of the casting die in the film width direction, a scale dissolution liquid is dropped under the scale dissolution droplet. Means are preferably provided. Outside the left and right side walls and the rear wall of the decompression chamber having the main decompression chamber, and outside the left and right side parts and the rear part of the decompression chamber, there are provided outer walls at predetermined intervals. In addition, it is a preferred embodiment that a sub decompression chamber that opens downward is formed in advance so that the decompression force of the sub decompression chamber is larger than the decompression force of the main decompression chamber in the range of −30 to −300 Pa.

Also, it is preferable that the gaps 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 side walls and the rear outer wall of the sub decompression chamber facing these are 10 to 300 mm.

The wall surface other than the surface of the decompression chamber other than the surface in contact with the casting die is doubled to form a sub decompression chamber, and the decompression force of the sub decompression chamber outside the decompression chamber is made larger than the decompression force of the main decompression chamber inside the decompression chamber. Then, by strongly sucking, the flow of suction air from the side surface to the casting liquid film in the discharge direction of the casting liquid film is blocked, and even if the production speed of the film is increased, the entrainment air is In addition to being able to eliminate foaming due to entrainment, the stability of the casting liquid film is improved even when the pressure drop rate is increased due to the increase in the dope discharge speed that accompanies the high-speed film formation. It is possible to reduce unevenness in film thickness in the film transport direction due to vibration of the film, and it is possible to produce a film having good smoothness.

Further, the excess solution of the scale solution dropped from the scale solution droplet lowering means to the widthwise both ends of the web at the casting die edge during film formation can be sucked and recovered toward the sub decompression chamber. There is no transfer failure due to the scattering droplets of the excess solution of the scale dissolving solution dropped, and a film with excellent flatness is obtained, and the accumulation of dirt on the endless support due to the scattering droplets of the excess solution of the scale dissolving solution. It is possible to manufacture a thin film having a wide width and a high production efficiency, excellent quality and capable of high-speed film formation.

If the gaps 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 side walls and the rear outer wall of the sub decompression chamber facing them are 10 to 300 mm, the decompression chamber is a so-called decompression chamber. The inside and outside are doubled and the entrained air is relatively strongly sucked from the auxiliary decompression chamber with a predetermined gap on the outside of the decompression chamber by a decompression force larger than the decompression force of the main decompression chamber on the inside of the decompression chamber, so that the casting is performed. The suction air from the side surface to the liquid film edge can be reduced, stable casting is realized, and the excess solution of the scale solution blown off from the casting die edge (left and right ends) is supported. There is an effect that it can be collected in the sub decompression chamber having a strong suction force (decompression force) from the outside, and a high-quality film can be stably produced at a high production rate for a long period of time.

Also, it is preferable that the gas concentration near the casting dope of the decompression chamber is 80% or less.

This is because when the concentration of gas (mainly volatile organic solvent vaporized) in the air near the casting bead rises and the gas component reaches the desired concentration, it may liquefy, and the liquefied solvent is cast. It may adhere to the beads and make the casting film defective. Further, when the pressure is reduced on the endless support contact surface (hereinafter referred to as the casting bead back surface) side of the casting bead, the formation of the casting bead is stable, but in this case, the gas is easily liquefied. In some cases, the liquefied solvent may adhere to the casting film, or may adhere to the decompression chamber to cause non-uniform decompression. In such a case, there is a problem in that a surface defect of the manufactured film causes optical unevenness or unevenness in the width direction of the film (hereinafter referred to as lateral unevenness). It is improved by setting the gas concentration to 80% or less.

That is, by setting the gas concentration to 80% or less, it is possible to prevent the gas component from liquefying and prevent the gas component from liquefying and causing a failure to adhere to the casting bead. In the film obtained by the above method, the occurrence of optical unevenness and horizontal unevenness is suppressed.

It is preferable that the degree of pressure reduction in the pressure reducing chamber be within a range of -1500 to -200 Pa with respect to atmospheric pressure. The discharge speed of the dope is preferably in the range of 7 to 40 m/min.

From the viewpoint of preventing liquefaction, it is also preferable to spray a solvent gas near the casting beads. 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. Further, the solvent is a mixture containing a compound containing the largest amount of dichloromethane and dissolving or dispersing the polymer, and the proportion of dichloromethane gas contained in the vapor is preferably 80% by volume or more.
As the mechanism for spraying the solvent gas, the one described in JP2013-156488A 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 entrained air is prevented from being applied to the casting bead and the uneven thickness 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, Among 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 can have a decompression degree lower than that on the downstream side. preferable. The gap between the vacuum 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.

When the maximum absolute pressure of each decompression chamber is Pn (Pa), the pressure of each decompression chamber should be in the range of 0.9 x Pn (Pa) or more and 1 x Pn (Pa) or less. Is more preferable, and it is more preferable to adjust to a 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 each decompression chamber is preferably provided with an exhaust port.

Also, it is preferable to spray a 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 part of the blower unit is provided with a nozzle having a slit-like blower port formed long in the width direction of the casting bead.

-The blower unit is installed downstream of the casting die in the running direction of the endless support and above the endless support. The lower part of the blower unit is provided with a nozzle having a slit-shaped blower port formed long in the width direction of the casting bead, from the blower port to the slit outlet, and in the entire widthwise region of the casting bead. The solvent gas containing the vapor of the solvent used for the preparation of the dope is sent toward the slit, and the solvent gas is maintained at a high concentration in the vicinity of the slit outlet so as not to liquefy the solvent gas. 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 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 in which the solvent gas concentration in the vicinity of the casting bead is maintained high in this way, the drying of the casting bead is prevented. Therefore, the dope is solidified in the vicinity of the exit of the slit to become a foreign substance and is prevented from adhering to the film. Therefore, it is possible to manufacture a film excellent in surface condition without streak failure or the like.

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 Kawaburari (excessive end film) may occur at the slit end. There is a problem that it is difficult to apply a stable state in a wide range over a long term.

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

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

It is preferable to use, for example, methyl acetate as the solvent flowing down the nozzles on both sides of the casting die. 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 is reduced, but the occurrence of Kawaburari can be suppressed. Although this factor is not clear, it can be presumed 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, on a metal endless support, before casting the dope or the resin melt, the metal endless support surface, atmospheric pressure plasma irradiation or excimer UV irradiation The surface treatment is preferably carried out by

In this case, it is preferable that the integrated time of the atmospheric pressure plasma irradiation processing or the excimer ultraviolet irradiation processing is 0.1 to 3000 seconds, preferably 0.5 to 500 seconds.

Here, if the integrated 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 integrated time of the atmospheric pressure plasma irradiation treatment or the excimer ultraviolet irradiation treatment exceeds 3000 sec, the surface is roughened and roughened, which is not preferable.

According to the present invention, a high-energy surface treatment is performed by a high-energy irradiation device (A) consisting of an atmospheric pressure plasma device and an excimer ultraviolet device, and the surface of an endless support made of metal rather than a surface oxide film naturally formed in the atmosphere. In addition, 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 unit or two or more units 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 proportions in each die, or the dope may be fed to the dies from a plurality of precision metering gear pumps in respective proportions. 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 steps may be the same or may be different at different points in the step. If different, the temperature may be a desired temperature immediately before casting.

The cast width can be in the range of 1 to 4 m, preferably in the range of 1.5 to 3 m, and 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 the temperature is too high, the web may foam or the flatness may deteriorate. The preferable temperature of the endless support is appropriately determined in the range of 0 to 100° C., more preferably in the range of 5 to 30° C. Alternatively, it is also a preferable method that the web is gelated by cooling and peeled from the drum in a state of 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 warm water because the heat can be efficiently transferred, so that the time until the temperature of the metal endless support becomes constant is short. When using hot air, in consideration of the temperature decrease of the web due to the latent heat of evaporation of the solvent, while using hot air above the boiling point of the solvent, while preventing foaming, there may be a case where the air temperature is higher than the target temperature. .. In particular, it is preferable to change the temperature of the endless support and the temperature of the drying air between the casting and the peeling to efficiently perform the drying.

　The casting die is preferably a pressure die that can adjust the slit shape of the die base and makes the film thickness uniform. The pressure die includes a coat hanger die, a T-die, and the like. Even if two or more pressure dies are provided on a metal endless support in order to increase the film formation speed, the dope amount may be divided and laminated. Good.

Edge failure called kawabari may occur during solution casting, but the cause of this failure is due to minute defects at the tip of the die. The die defects include minute scratches and dents that are associated with die manufacturing and maintenance, and scratches that occur during grinding with a grindstone.

Therefore, further studies were conducted to develop a method for preventing the occurrence of Kawaburari due to minute defects at the tip of the die. As a result, WC coating was applied to the tip portion of the casting die lip where the dope came in contact with the liquid to remove the solvent from the solvent. In the method of producing an acrylic resin film by casting from a solution die slot melted in, when the hardness Hv of the die tip is 400 or more, minute scratches caused during die production, maintenance, and installation, It was found that dents were suppressed and streak defects in the casting direction improved until it became difficult to confirm. The hardness represented by Hv (Vickers hardness) is a value obtained by using a diamond pyramid having an apex angle of 136° as an indenter, reading the length of the diagonal line of the generated indentation, and dividing the load by the surface area of the depression. ..

Further, in a method for producing an acrylic resin film by casting a solution of a resin in a solvent through a slot of a die, by setting the surface tension of the tip of the die to 380 μN/cm or more, the occurrence of Kawaburari is prevented, It was further found that the streak defects were improved. The surface tension is based on JIS K6768, manufactured by Wako Pure Chemical Industries, Ltd., standard index of wetting index, No. 32 to No. It is the value measured using 54.

Furthermore, in order to prevent the occurrence of Kawaburari, the surface irregularity of the lip tip and the corners between the slot surface and the flat end surface that intersects the slot surface are formed into a curved surface with a substantially arcuate shape, and the curvature is It was found that the radius of curvature of the surface was small and the solvent wettability was required to be good, and it was possible to prevent the burrs at the tip of the lip and improve the streak defect.

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

The parallelism between the boundary line between the curved surface, the slot surface and the flat end surface and the line connecting the centers of curvature of the curved surfaces is within the range of 1.5 to 15 μm per 1 m in the longitudinal direction of the slot. Preferably. 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 centers of curvature of the curved surfaces is 0 m of the radius of curvature R per 1 m in the longitudinal direction of the slot. It is preferably not more than 3 times. Furthermore, 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 centers of curvature of the curved surfaces is within the range of 0.5 to 5 μm per 1 mm in the longitudinal direction of the slot. Is preferred. Furthermore, 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 centers of curvature of the curved surfaces is 0 mm of the radius of curvature R per 1 mm in the longitudinal direction of the slot. It is preferably less than 1 time.

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

If the surface temperature of the rotating roller is high after casting the dope on the metal endless support from the die, the effect of promoting gelation of the casting film cannot be sufficiently obtained. Further, since the dew point at the stripping section is high, dew condensation may occur on the surface of the casting film at the stripping section, and even if the condensed water is dried and volatilized in a later step, it is said that clouding occurs 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, from the first rotating roller whose surface temperature is -30°C to 6°C, The casting film directed to the second rotating roller is dried by dry air, the casting film is conveyed from the second rotating roller to the first rotating roller, and then peeled off at a peeling position where the dew point is 0° C. or lower. , The first rotating roller and the cooling means provided upstream of the peeling position cool the casting film on the belt toward the first rotating roller, and the cooling section to the peeling position is adjusted at the position of the cooling means. Therefore, the temperature of the cast film to be stripped off is preferably lower 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. Thus, it is preferable to cool the casting film on the belt from the second rotating roller toward the first rotating roller.

Further, it is preferable that the dew point at the peeling position is 0° C. or lower by adjusting the temperature inside the casting chamber accommodating the first rotating roller and the second rotating roller. In that case, it is preferable that the solvent content on the dry basis at the peeling position of the casting film is in the range of 10 to 200% by mass. That is, since the dew point of the casting film in the vicinity of the peeling position is 0° C. or less, dew condensation is prevented and water is prevented from adhering to the casting film. This will prevent fogging on the surface of the produced film.

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

In general, in the case of an endless support having a completely smooth surface, both ends are easily broken when the web is peeled off, so that production is often interrupted due to a break accident. On the other hand, by providing the roughened zone, the releasability becomes very good, no film is formed and no bubbles are generated, which is very effective. The width is a width from 5 to 30 mm inside the dope film to both ends of the endless support so that the casting position may be slightly shifted in the width direction. If the average roughness Rz of the roughened zone is smaller than 0.5 μm, there is no roughening effect, and the adhesion is too strong and peeling is difficult. Adhesion is easy and peeling is difficult. The preferable range of Rz is 0.8 to 1.5 μm.

In recent years, there has been a demand for higher production speed and thinner film, but in order to increase the speed, the temperature of the hot air blown to the casting film on the endless support must be increased, so There is a problem that the conventional method is insufficient as a countermeasure against foaming because the temperature of the side edge of the stretched film rises and foaming is more likely to occur, and as the film becomes thinner, it becomes susceptible to the temperature of the endless support. ..

Therefore, while providing a wind shielding member so as to partition the casting film on the endless support into a central area and a side edge area in the width direction, hot air is blown to the central area, and the width direction of the casting film is increased. It is preferable to make the temperature distribution uniform. Cool air may be blown to the side edge area from the inner side to the outer side in the width direction of the casting film on the endless support to make the temperature distribution in the width direction of the casting film uniform.

Also, it is preferable to blow cool air from the inner side to the outer side in the width direction of the casting film on the endless support to make the temperature distribution in the width direction of the casting film uniform.

The wind shield member may be provided in parallel with the side edge of the casting membrane in the range of 20 to 100 mm, more preferably 20 to 80 mm, from the side edge to the center side. In addition, the gap between the wind shielding member and the casting film is preferably in the range of 5 to 30 mm, more preferably 5 to 15 mm.

Specifically, the cool air is blown by a blower duct, and the blower port of the blower duct is provided parallel to the side edge of the casting membrane in the range of 20 to 100 mm from the side edge to the center side, It is advisable to set the gap between the casting film and the casting film to be in the range of 5 to 30 mm and to blow the cold air so that the cold air has an intersecting angle of 45 to 90°, more preferably 60 to 80°. The cold air has a dew point of −2° C. or lower and a temperature in the range of 15 to 60° C., and the cool air is preferably blown at a wind speed of 1 to 10 m/sec.

Also, it is preferable to perform so-called initial drying, in which the surface of the casting film immediately after being formed on the endless support is dried using a drying device. Thus, the initial drying can effectively promote the evaporation of the solvent from the casting film.

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

Therefore, the temperature (° C.) is within the range of 30 to 160° C. from the first air blower provided so as to face the metal endless support and having the width direction of the metal endless support as the longitudinal direction. A first drying step of sending out a substantially constant dry air to the casting film immediately after being formed while adjusting the static pressure (Pa) to be substantially constant within a range of 50 to 200 Pa; After the first drying step, from the second air outlet provided so as to face the running direction of the endless support, according to the residual solvent amount of the casting film, the running direction of the endless support is It is preferable to perform a casting film drying method including a second drying step of sending out substantially parallel drying air.

Further, it is preferable that a partition member is provided inside the first blower port to divide the endless support into at least three areas in a direction parallel to the traveling direction. An air volume control member is provided in a section located above both ends of the casting membrane in the first air outlet section to adjust the air volume of the dry air to be sent in the width direction of the endless support. Is preferred.

It is preferable to perform the first drying treatment while the residual solvent amount of the casting film is up to 250% by mass, and the temperature (°C) from the second blowing port is substantially constant within the range of 30 to 160°C. 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 in parallel with the running direction of the endless support. preferable.

In addition, due to the recent increasing demand for quality, unevenness in unevenness having a periodic structure is likely to become a problem. The following are examples of means for preventing unevenness having this periodic structure.
In the method for producing an acrylic resin film of the present invention, when the dope is cast from the die onto the support, it is preferable to keep the windless state immediately after the casting.
If the wind flow is not uniform and the wind flow is non-uniform, the initial drying of the dope will be disturbed according to the non-uniformity, and the drying speed will vary locally, causing flow of the dope and film thickness. Uniformity may be impaired.
Further, even if a uniform wind is blown, the air layer side surface of the casting film is rapidly cooled by the latent heat of vaporization, and a temperature gradient is applied in the layer direction of the casting film between the temperature-controlled belt side contact surface, So-called Benard convection occurs depending on the environment. For this reason, the uniformity of the film thickness may be impaired due to the difference in the drying speed in the regular pattern on the film surface. For uniform film thickness, it is preferable to dry the film without air flow until the flowability of the cast film becomes small. Specifically, it is preferable to set the environment where the wind speed is 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 casting from the outside to block the flow of wind, but it is necessary to convey the belt that is the support, and the organic solvent that has volatilized Must be discharged, and it is impossible to build a completely closed system. Therefore, it is preferable to precisely calculate the pressure difference between the adjacent areas and the shape of the opening between them to design the wind speed near the casting membrane surface to fall within the above range.

In order to improve the releasability of the casting film from the metal endless support, a cooling body in a specific temperature range is provided on the surface opposite to the dope film separation side of the moving endless support that is in contact during separation. By bringing them into contact with each other and controlling the amount of residual solvent at the time of peeling within a specific range, the peelability is improved, and good peeling from the endless support is possible. That is, the residual solvent amount when stripping the casting film is controlled to 100% by mass or less, and in the region where the casting film is stripped from the endless support, the casting film peeling side of the endless support is It is preferable to bring a cooling body having a surface temperature of 10° C. or less into contact with the opposite surface.

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

It is preferable that the cooling body also serves as a roller that can rotate 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 brilliantler using an antifreeze is 10° C. or lower (upper limit is preferably 5° C. or lower, more preferably 0° C. or lower, particularly It is 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 metallic endless support to −50 to 10° C., and the cooling rate from the time when the acrylic resin resin solution is cast onto the metallic endless support to the time when it is peeled off. Is expressed as (temperature difference/hour), it is preferably 3 to 5 (° C./sec).

Further, in that case, it is preferable from the viewpoint of peelability that the poor solvent ratio in the dope is adjusted to a range of 2 to 20% by mass.

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 into the manifold of the casting die from the plurality of supply ports.

(Layer casting)
When performing multi-layer casting such as co-casting, the lip clearance of the casting die is narrowed to increase the shear at 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. When forming a multi-layer film, the stick-slip itself becomes weaker by reducing the viscosity of the dope forming the outer layer (surface layer, air surface layer and/or back surface layer, endless support surface layer) Deformation will not occur. Furthermore, 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-cast from a casting die to form a multilayer film, the multilayer film at a temperature T1 (° C.) at the time of casting the dope 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, 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 casting the dope is preferably in the range of 5 to 60 Pa·s, and 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 0.9 to 1.2 mm, and most preferably 0. 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 base layer dope, the endless support surface layer dope, and the air surface layer dope have different viscosities, and the thickness t1 (μm) of the base layer forming the casting film and the endless support surface layer It is preferable that the relationship between the thickness t2 (μm) and the thickness t3 (μm) of the air surface layer is t2≦t3≦t1. Further, it is preferable that the ratio of t3 to the thickness of the casting film is 3% or more and 40% or less.

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

The mass A of the air surface layer dope and the mass B of the organic solvent contained in this dope preferably satisfy 16≦{(AB)/A}×100≦21.

The raw material dope is preferably stirred and mixed with an in-line mixer after adding the additive, and the in-line mixer is provided so as to extend in the diameter direction of the pipe through which the raw material dope flows, and has a slit-shaped addition serving as an input port for the additive. It is preferred to have a mouth.

The length L of the addition port, which is parallel to the radial direction of the pipe, is preferably 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. Furthermore, 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 producing an acrylic resin film is generally performed on the surface side of a metal endless support (for example, a drum or a band), that is, the surface of a web on the metal endless support. From the back side of the drum or band, contacting the temperature-controlled liquid from the back side, which is the opposite side of the dope casting surface of the band or drum, to heat the drum or band by heat transfer. Although there is a liquid heat transfer method for controlling the surface temperature, the back surface liquid heat transfer method is preferable. Alternatively, the IR heater described below is also preferably used. The surface temperature of the metallic endless support before casting may be any number as long as it is equal to or lower than the boiling point of the solvent used for the dope. However, in order to accelerate the drying and to lose the fluidity on the metal endless support, the temperature is 1 to 10° C. lower than the boiling point of the solvent having the lowest boiling point. It is preferable to set. This is not the case when the cast dope is cooled and peeled off without drying.

(Peeling)
It is a step of peeling the web, in which the solvent is evaporated on the metal endless support, at the peeling position. The peeled web is sent to the next step 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 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 in the range of 10 to 100% by mass, but when peeling at a time when the amount of residual solvent is larger, if the web is too soft, the flatness is deteriorated during peeling, and cracks or vertical streaks due to peeling tension occur. Since 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).

Formula (Z)
Amount of residual solvent (%)=(mass before heat treatment of web−mass after heat treatment of web)/(mass after heat treatment of web)×100
Note that the heat treatment for measuring the amount of residual solvent means performing heat treatment 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 easily occur during peeling, peeling is performed with a tension of 190 N/m or less. Preferably.

In the present invention, the temperature at the peeling position on the metallic 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 preferred is

When peeling a raw dry film from a metal endless support, if the peeling resistance (peeling load) is large, the film is stretched randomly in the film forming direction, causing optical anisotropic unevenness. In particular, when the peeling load is large, a stepwise stretched portion and a non-stretched portion are alternately generated in the film forming direction, and the retardation is distributed. When the liquid crystal display device is loaded, the line-shaped or band-shaped unevenness becomes visible. In order not to cause such a problem, it is preferable that the peeling load of the film is 2.5 N or less per 1 cm of the peeling width of the film. The peeling load is more preferably 2 N/cm or less, still more preferably 1.8 N or less, and particularly preferably 1.5 N or less. When the peeling load is 2.5 N/cm or less, unevenness due to peeling is not observed at all even in a liquid crystal display device in which unevenness is likely to occur, which is particularly preferable. As a method for reducing the peeling load, there are a method of adding a peeling agent as described above and a method of selecting a solvent composition to be used.

The peeling load is measured as follows. The dope is dropped on a metal plate of the same material and surface roughness as the metal endless support of the film forming apparatus, spread using a doctor blade to a uniform thickness and dried. The film is cut into a uniform width with a cutter knife, the tip of the film is peeled off by hand, and the film is sandwiched by a clip connected to a strain gauge, and the load change is measured while pulling up the strain gauge in a direction at an angle of 45 degrees. The volatile content in the peeled film is also measured. The same measurement is performed several times while changing the drying time, and the peeling load at the same time as the peeling residual volatile content 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 the peeling speed close to the actual peeling speed.
As a means for reducing the peeling load, a peeling accelerator described later can also be preferably used.

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

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

At that time, it is preferable to perform the film formation at a rate of 10 to 150 m/min. The peeling temperature is preferably in the range of 5 to 50°C.
The surface energy of the peeling roller is preferably in the range of 10 to 35 mN/m, more preferably 18 to 26 mN/m. For the surface treatment of the stripping roller to achieve such a range, treatments such as Hypercoat, Chloamol, Tungsten Carbide, and Amucoat are conceivable, but Ultrachrome II treatment is particularly preferable.

In addition, the film immediately after being peeled off from the endless support is a thin soft film, and the film is made thin by a roller transfer process or a tenter transfer process in which both ends of the film (hereinafter, referred to as edge ends) are transferred. The so-called thinning causes a problem that stable conveyance becomes difficult. Further, if the thickness of the edge portion of the film is excessively increased, there are cases where bald residue or the like occurs in high-speed film formation.

Therefore, even if the film is thinned, in order to secure the transport stability, it is preferable to increase the thickness of only the film edge end by a method other than the lip clearance adjustment, separately from the flow path of the die body. A dope channel for thickness correction of each edge is provided, and the flow rate of the dope passing therethrough is controlled by an adjustment mechanism other than the clearance adjustment at the tip of the die lip to adjust the thickness of the dope for both ears. A method in which the film is supplied to the edges and the thickness is independently controlled only at both edges of the film is preferable.

As a manufacturing apparatus that can be specifically used, in a manufacturing apparatus of a film in which a dope is cast on an endless support from a die body having a dope channel, the film is formed in the die separately from the dope channel. It is possible to independently control the thickness of both ends of the film, by providing both end thickness correction channels. It is preferable that the apparatus is equipped with an adjusting mechanism for adjusting the flow rate of the correction dope passing through the correction channel, and can independently control the thickness of both ends of the film. It is preferable that the correction flow path has an air vent. It is preferable that the correction flow path has a heat retention mechanism that can be controlled independently of the die body, and the correction flow path outlet is formed from a flow path having a casting width of the die main body to a die lip. It is preferable that it is provided up to the tip.

According to the method for producing the film, both end portions of the casting film are thickened, the strength of the film is increased as the casting film as a whole, and when the thin casting film is peeled from the endless support, the unpeeled residue, etc. It is possible to suppress the occurrence of abnormalities. Incidentally, the method of thickening only the both ends of the casting film in this manner, in addition to the dope channel provided in the body of the die, the die is provided with the film both ends thickness correction channel, The correction dope is supplied from the correction flow path, and the thickness of both ends of the film is independently controlled, so that the present invention can be carried out only by making a slight improvement to conventional equipment. Therefore, the cost can be reduced. Further, by controlling the flow rate of the correction dope that passes through the correction flow path by using an adjustment mechanism different from the clearance adjustment of the die lip tip, it is possible to more accurately control the film thickness. It can be carried out.

(Atmosphere in the casting process)
In the casting step according to the present invention, the oxygen concentration in the casting step is preferably at least less than 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 will be less than 10 vol% in the drying step as well. If there is no air permeability between the two, 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 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 limit of explosion.

In order to reduce the oxygen concentration in the casting step to less than 10 vol%, an inert gas such as nitrogen gas or carbon dioxide, or a mixture of an inert gas and air, in which the oxygen concentration is less than 10 vol%, is used. It can be done by supplying. It is preferable to measure the oxygen concentration in the casting step 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 performed separately in 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 end portions of the web like a tenter dryer. May be fixed with a clip and dried while being transported.

The means for drying the web is not particularly limited, and generally, hot air, infrared rays, heating rollers, microwaves, etc. can be used, but hot air is preferable in terms of simplicity.

An IR heater is mentioned as a suitable drying method using infrared rays. The IR heater will be described below.
The drying means in the present invention is most preferably hot air drying, but it is also preferable to supplementarily use an infrared heater (IR heater).
When a wet film containing a solvent is irradiated with infrared rays from an IR heater, the movement of solvent molecules that have absorbed the infrared rays is activated, and movement of the solvent molecules in the film can be promoted. 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 has no absorption in this irradiation wavelength band.
Further, in contrast to the phenomenon that energy is taken from the wet film as evaporation latent heat when the solvent molecules are volatilized to lower the temperature of the film, absorption by an IR heater is faster than heat conduction in hot air drying, and efficient drying is possible. I think I can. This effect is more exerted in the first half drying with a large amount of solvent than in the latter half drying with a small amount of solvent. Therefore, it is preferably applied during belt drying-peeling-initial drying.
IR heaters are provided by NGK Insulators, Ltd., Hibeck Co., Ltd., Kashima Co., Ltd., etc. The irradiation method can be appropriately selected from line focusing, parallel irradiation and the like. It is preferable to adjust the irradiation time, the output energy, the number of heaters, etc., as appropriate.
The high temperature part of the IR heater and the volatile solvent are preferably isolated. That is, it is preferable that the filament portion of the IR heater, which has a locally high temperature, be protected by a transparent cooling system. For this reason, it is preferable to cover with a double tube made of quartz glass and to cool the glass by flowing water in the glass gap. This makes it possible to block the heat without blocking the infrared rays emitted from the filament.
The present inventors have discovered that curling of an optical film obtained by irradiation with an IR heater is suppressed. Although this mechanism is not clear, it is presumed that the evaporation by infrared absorption may make the movement of solvent molecules in the film more uniform than the evaporation by heat transfer, and the difference in physical properties between the front and back surfaces of the film may become smaller. There is. This effect is particularly exhibited by heating with an IR heater before introducing a tenter that heats at Tg or higher.
Due to the occurrence of curl, the stress applied to the entire width of the film during roll conveyance becomes non-uniform, and scratches and wrinkles are formed on the film.
In addition to the above effects, it was also found that the film thickness deviation in the central part of the film is improved by irradiating the IR heater only on the end part of the film before introducing the tenter. Although this mechanism is still being clarified, it is assumed that the viscoelasticity of the film in the tenter clip has changed and the stress distribution in 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 heat treatment within a range of 10 to 60 minutes at a temperature of 100° C. or higher. The drying temperature is 100 to 200° C., more preferably 110 to 160° C.

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

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

Thus, for example, the following stretching steps are possible:
・Stretching in casting direction → stretching in width direction → stretching in casting direction → stretching in casting direction ・Stretching in width direction → stretching in width direction → stretching in casting direction → stretching in casting direction Simultaneous biaxial stretching also includes 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.

If the amount of the residual solvent is 2% by mass or more, the film thickness deviation is small, and it is preferable from the viewpoint of flatness.

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

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

One of the methods for producing an acrylic resin film according to the present invention comprises a stretching step of stretching in a direction (TD direction) orthogonal to the transport direction of the film, and comprises a heat treatment step downstream of the stretching 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 to 50 to 300 mm, and the transport tension of the film is set to 15 to 100 N/m. Heat treatment is performed within the range. Here, the glass transition temperature (Tg) refers to the glass transition temperature temperature of the completed 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) of the film is reduced in another step downstream of the stretching step while suppressing shrinkage in the width direction of the film. By applying the above temperature, the shrinkage of the film in the MD direction (the transport direction of the film), which cannot be achieved by the conventional cellulose ester resin produced by the solution film-forming method, is promoted, and the retardation in the thickness direction ( Not only the decrease in 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%.

Note that the "stretching ratio (%)" here means the value obtained by the following formula.

Stretching ratio (%)=100×{(length after stretching)−(length before stretching)/length before stretching There is no particular limitation on the method for stretching the web in the film conveying direction. For example, a method in which the peripheral speed difference is applied to multiple rolls and the roll peripheral speed difference between them is used to stretch in the longitudinal direction, both ends of the web are fixed with clips or pins, and the spacing between the clips or pins is widened in the traveling direction. And a method of stretching in the longitudinal direction, or a method of simultaneously stretching in the longitudinal and lateral directions and stretching in both the longitudinal and lateral directions. 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 a linear drive method because smooth stretching can be performed and the risk of breakage can be reduced. The stretching in the machine direction uses an apparatus having two nip rolls, and the rotational speed of the nip roll on the outlet side is made faster than the rotational speed of the nip roll on the inlet side, so that the cyclic 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 (TD direction) orthogonal to the transport direction of the film, a heat treatment step on the upstream side of the stretching step, and the film is formed in the heat treatment step. The glass transition temperature (Tg) is not less than −50° C. and not more than Tg+20° C., the roll span of the guide roll in the heat treatment step is in the range of 50 to 300 mm, and the film transport tension is in the range of 15 to 100 N/m. It is preferable that the film is subjected to heat treatment as described above, the film is once cooled to a temperature not higher 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 upstream of the stretching step, and then the cooling step is performed again. By stretching again while raising the temperature to near the glass transition temperature (Tg), an appropriate combination of in-plane retardation (Ro) and thickness direction retardation (Rt) can be realized, and the film The haze value of can be reduced.

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

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

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

FIG. 4 schematically shows an example of a tenter stretching device 201 that is preferably used in manufacturing the acrylic resin film according to the present invention. In the figure, the tenter stretching device 201 is schematically illustrated, but normally, 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, which are endless chains. Of the 202a, 202b, the left and

right chains

201a, 202b, 202b of the chain forward side straight line transition portion that grips and pulls both left and right ends of the film (F) are gradually separated in the width direction of the film (F). The track 201b is installed so that the film F is stretched in the width direction.

In FIG. 4, in step A, the web (film) F separated from the endless support (not shown) and conveyed is gripped by the left and right gripping means (clips) 202a and 202b. 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 same drawing, and in step C, the stretching is completed, and the web is gripped and conveyed. D is a step of relaxing the web in the width direction.

It is preferable to provide a slitter for cutting off the edge in the web width direction after the web is peeled from the endless support but before the step B is started and/or immediately after the step C. In particular, it is preferable to provide a slitter for cutting off the web end just before starting the step A. When the same stretching is performed in the width direction, comparing the case where the web end is cut off before the start of the process B and the condition where the web end is not cut off, the former shows the distribution of the optical slow axis (orientation angle (Also called distribution) is obtained.

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

Note that the stretching operation may be performed in multiple stages, and it is preferable to perform biaxial stretching in the casting direction and the width direction. Also, when biaxial stretching is performed, simultaneous biaxial stretching may be performed or stepwise implementation may be performed. In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, or stretching in the same direction can be divided into multiple stages, and stretching in different directions can be added to any of the stages. Is also possible.

It is particularly preferable that the web peeled from the metal endless support is conveyed while being dried, and further stretched in the width direction by a tenter method in which both ends of the web are gripped by pins or clips, whereby a predetermined phase difference is obtained. 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 1.05 to 2 times, preferably 1.15 to 1.5 times. At the time of simultaneous biaxial stretching, it may be contracted in the machine direction, or may be contracted so as to be 0.8 to 0.99, preferably 0.9 to 0.99. Preferably, the area is 1.12 to 1.6 times, and preferably 1.15 to 1.5 times due to the transverse stretching and the longitudinal stretching or contraction. This can be obtained by multiplying the draw ratio in the longitudinal direction by the draw ratio in the transverse direction.

Further, the "stretching direction" in the present invention is usually used to mean a direction in which a stretching stress is directly applied when a stretching operation is performed, but when biaxially stretching in multiple stages, the final In some cases, it is used in the sense of the one having a larger draw ratio (that is, the direction normally serving as 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, the range of 1 to 10 seconds is preferable, and the range of 4 to 10 seconds is more preferable.

In the tenter process, the heat transfer coefficient may be constant or may be changed. The heat transfer coefficient preferably has a heat transfer coefficient in the range of 41.9 to 419×10 ³ J/m ² hr. More preferably, it is in the range of 41.9 to 209.5×10 ³ J/m ² hr, and most preferably in the range of 41.9 to 126×10 ³ J/m ² hr.

The stretching speed in the width direction in the above 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.

In the step B, it is preferable to control the stress in the first 10 cm 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, and 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 across the width of the web will also be reduced.

In step D, it is preferable to relax in the width direction. Specifically, it is preferable to adjust the web width so that it is 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 capable of independently controlling the gripping length (distance from gripping start to gripping end) of the web by the left and right gripping means of the tenter.

As a means for independently controlling the lengths of the portions gripping the left and right ends of the web by the tenter stretching device to make the gripping length of the web different between the left and the right, specifically, for example, shown in FIG. There is something like this.

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

In the figure, the installation positions of the

clip starters

203a and 203b at the grip 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 is generated in the tenter stretching device 201, and the positional deviation due to conveyance other than the tenter stretching device 201 is corrected. It is possible to effectively prevent the web from meandering, fraying and wrinkling even if the conveying distance from the peeling to the tenter is long.

Further, in the present invention, in order to correct wrinkles, cracks, distortions, etc. more accurately, it is preferable to add a device for preventing meandering of the long film, and the edge position controller (JP-A-6-8663) ( A meandering correction device such as an EPC) or a center position controller (also sometimes referred to as CPC) is preferably used. These devices detect the edge of the film with an air servo sensor or an optical sensor and control the transport direction of the film based on the information, so that the edge of the film or the center in the width direction becomes a constant transport position. Specifically, as the actuator, specifically, one or two guide rolls or a flat expander roll with a drive is moved left and right (or up and down) with respect to the line direction to correct the meandering or the film. We installed a pair of small pinch rolls on the left and right (one on each side of the film, one on the front and one on the back of the film), and sandwiched the film with this to correct the meandering. Yes (cross guider method). The principle of the meandering correction of these devices is such 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 uses the right side A pair of pinch rolls are nipped 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.

The following problems were encountered when stretching was performed using a tenter stretching device.
(1) Since stress concentrates on the gripped portion of the film, breakage easily occurs.
(2) Volatile precipitates such as additives adhere to the film surface to cause quality defects.
(3) At the exit of the tenter, the deformation of the film at the grip is large, and slits (edge cutting) cannot be performed.
In order to solve this problem, it is preferable to adjust the temperature of the holding tool to a temperature not lower than the boiling point of the organic solvent and lower than the stretching temperature to hold the casting film.
When the temperature of the gripping tool for gripping the web is lower than the boiling point of the organic solvent used, the organic solvent in the gripping part dries slowly, becomes softer than the central part of the web, and breaks frequently. Further, additives and the like in the web may be deposited on the gripping portion to cause breakage and quality defects. Further, when the temperature of the gripping tool is equal to or higher than the stretching temperature, the gripping portion is in contact with the web, and therefore the heat transfer rate is higher than that of the central portion of the web, so that the web temperature of the gripping portion becomes higher than that of the central portion of the web. However, the breakage frequency increases. A more preferable range of the temperature of the gripping tool is a temperature 10°C or higher higher than the boiling point of the organic solvent used and a temperature 10°C or lower lower than the stretching temperature.

The method of adjusting the temperature of the gripping tool within a predetermined temperature range is not particularly limited, but it is preferable to provide heating/cooling means on the return side of the gripping part. For example, it is possible to preferably use a method of directly blowing hot air or cold air whose temperature has been adjusted to the gripping portion, a method of passing the gripping portion through a temperature-controlled zone, and the like. In addition, on the return side of the grip portion, it is preferable to keep the temperature of the grip tool at a temperature not lower than the temperature at which the additives and the like in the web do not deposit.

In the present invention, a method in which the transverse stretching is performed in two stages and the second stage stretching is performed at a temperature 1 to 50° C. higher than the first stage stretching temperature is also preferably used. There is no particular limitation on the method of raising 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, and a radiation such as a far infrared ray or microwave heating device. 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 stretching of the first stage and the second stage may be performed continuously, or after passing through a cooling process, a width holding process, a longitudinal direction or a relaxation process in the width direction after the stretching of the first stage, A second stage stretching may be performed. It is preferable to use a tenter method in which the temperature in the oven is set to be higher stepwise as it goes downstream so that the equipment can be made more compact.

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

The means for drying the web in this step is not particularly limited, and generally, hot air, infrared rays, heating rolls, microwaves or the like can be used, but hot air is preferable in terms of simplicity.
In addition, when the web is dried while being transported, it is preferable that the temperature of the web is not too high. When the web is heated by applying tension in the transport direction and the temperature of the web is higher than the softening temperature of the web, wrinkles occur in the web and the web becomes defective. As a standard for the drying temperature (temperature of the web during drying), a low temperature range of 10 to 50° C. is preferable with respect to Tg when the web is completely dried. 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 should be raised stepwise, such as 30-50°C lower than Tg in the initial stage of drying, 20-40°C lower than Tg in the middle stage of drying, and 10-20°C lower than Tg in the final stage of drying. Is preferably carried out.
In order to suppress the occurrence of wrinkles during transportation, it is preferable to properly adjust the transportation tension. Particularly 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 the film width, and more preferably 10 to 50 N.

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

In the method for producing a long stretched film by oblique stretching, a long stretched film having a slow axis at an angle of more than 0° and less than 90° with respect to the width direction of the film is produced. Here, the angle with respect to the width direction of the film is an angle in the film plane. Since the slow axis in the plane of the film is usually expressed in the stretching direction or in the direction perpendicular to the stretching direction, by stretching 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 in the range of more than 0° and less than 90°.

An oblique stretching device is used to impart diagonal orientation to the long film. The oblique stretching device used in the present embodiment can freely set the orientation angle of the film by changing the path pattern of the gripping tool traveling support tool, and further, the orientation axis of the film can be set across the film width direction. It is preferable that the film stretching device be capable of uniformly orienting right and left with high accuracy and controlling the film thickness and retardation with high accuracy.

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

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

At the entrance of the oblique stretching device (the gripping tool is a gripping start point for gripping the long film, and a straight line connecting the gripping start points is indicated by a reference symbol A), both ends of the long film are held by a pair of left and right gripping tools (a pair of gripping tools). It is gripped by a gripping tool pair) and travels as the gripping tool travels.

The pair of gripping tools is composed of left and right gripping tools Ci and Co that are opposed to each other at the entrance of the oblique stretching device in a direction substantially perpendicular to the running direction (running direction before stretching) D1 of the long film. The left and right gripping tools Ci and Co travel on a left-right asymmetrical path, respectively, and are at positions at the end of stretching (the gripping tool is a gripping release point at which the gripping is released, and a straight line connecting the gripping release points is referred to as a reference numeral). The elongated stretched film grasped in (B) is released.

At this time, the left and right gripping tools Ci and gripping tools Co, which were facing each other at the entrance of the oblique 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. The gripping tool Ci traveling on the inner gripping tool travel support tool Ri has a positional relationship of advancing with respect to the gripping tool Co traveling on the outer gripping tool travel support tool Ro.

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

With the above actions, the long film will be stretched in the direction of θL. Here, “substantially vertical” means that the angle is in the range of 90±1°.

The oblique stretching device is a device that heats a long film to an arbitrary temperature at which it can be stretched and obliquely stretches it. 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 travel for supporting the traveling of the gripping tools. And a support.

Both ends of the long film that is sequentially supplied to the inlet of the stretching device (holding start point) are gripped by gripping tools, the long film is introduced into the heating furnace, and the outlet of the stretching device (holding release point) is gripped. Release the long stretched film from the tool. The long stretched film released from the gripping tool is wound around the winding core. The gripping tool running support provided with the gripping tool has an endless continuous track, and the gripping tool that has released the grip of the long stretched film at the exit of the stretching device is sequentially returned to the gripping start point by the gripping tool running support. It is supposed to be.

The gripping tool travel support may be, for example, a form in which an endless chain whose path is regulated by a guide rail or a gear includes the gripping tool, or an endless guide rail includes the gripping tool. It may be. That is, in the present invention, the gripping tool travel support may be, for example, an endless guide rail having an endless chain, or an endless guide rail having an endless chain. Alternatively, an endless guide rail without a chain may be used. The gripper travels along the path of the gripper travel support itself when the gripper travel support does not include a chain, and when the gripper travel support includes the chain, the gripper travels along the path of the gripper travel support. To run. Hereinafter, in the present invention, as an example, a case where the gripping tool travels along the path of the gripping tool travel support tool will be described. You may drive.

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

The gripping tool travel support of the stretching device has a left-right asymmetrical shape, and the pattern of the path of the gripping tool travel support depends on the orientation angle, the draw ratio, etc. given to the long stretched film to be produced. 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 travel support tool can be freely set and the pattern of the path of the gripping tool travel support tool can be arbitrarily changed.

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

In the embodiment of the present invention, the traveling speed of the grasping tool of the stretching device can be appropriately selected, but 15 to 150 m/min is preferable among them. When the traveling speed of the gripping tool of the stretching device is higher than 150 m/min, the local stress applied to the edge of the film becomes large at the bent portion, and 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 forming the gripping tool pair may be the same or different. If there is a difference in running speed between the left and right of the long stretched film at the exit of the stretching step, wrinkles at the exit of the stretching step and deviation may occur, so the speed difference between the left and right gripping tools forming the gripping tool pair is substantially 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 grasping tools forming the pair of grasping tools is constant, the difference between the traveling speeds of the respective grasping tools is preferably 1% or less, more preferably 0.5% or less, and further preferably Is 0.1% or less. In a general stretching device, there is speed irregularity that occurs on the order of seconds or less depending on the tooth cycle of the sprocket (gear) that drives the chain, the frequency of the drive motor, etc. 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 travel support that regulates the trajectory of the gripping tool, especially at the location where the long film is conveyed obliquely. For the purpose of avoiding interference between the gripping tools due to abrupt bending or local concentration of stress, it is desirable that the trajectory of the gripping tool is curved so as to draw an arc in the bent portion.

At the entrance of the oblique stretching device (the position of the straight line A in FIG. 7), the long film is sequentially gripped at both ends by the left and right grippers (a pair of grippers), and is run as the gripper travels. At the entrance of the oblique stretching device, a pair of gripping tools facing each other in a direction substantially perpendicular to the running direction D1 of the long film travels in a left-right asymmetric path and has a preheating zone, a stretching zone, and a heat fixing zone. Go through the furnace.

　The preheating zone refers to the section at the entrance of the heating furnace where the gripper holding both ends keeps running at a constant interval.

Extending zone refers to the section until the gap between the gripping tools that grips both ends begins to reach a predetermined gap. In the present embodiment, it can be stretched obliquely in the stretching zone, but is not limited to stretching in the diagonal direction, it may be diagonally stretched after transverse stretching in the stretching zone, or further after diagonal stretching. It may be stretched in the width direction.

ㆍThe heat setting zone refers to the section in which the grippers at both ends travel while maintaining parallel to each other in the period after the stretching zone where the gap between the grippers becomes constant again. After passing through the heat setting zone, it may pass through a section (cooling zone) in which the temperature in the zone is set to the glass transition temperature Tg° C. or lower of the acrylic resin forming the long film. At this time, in consideration of shrinkage of the long stretched film due to cooling, a path pattern may be set such that the interval between the gripping tools facing each other is narrowed in advance.

In order to adjust the mechanical properties and optical properties of the film, transverse stretching and longitudinal stretching may be performed as necessary in the process before and after introducing the long film into the oblique stretching device.

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

Note that in order to control the thickness unevenness in the width direction, a temperature difference may be applied in the width direction in the stretching zone. To make a temperature difference in the width direction in the stretching zone, a method of adjusting the opening degree of a nozzle that sends hot air into the temperature-controlled room so as to make a difference in the width direction, or a method of controlling heating by arranging heaters in the width direction is known. Can be used. The lengths of the preheating zone, the stretching zone and the heat setting zone can be appropriately selected. The length of the preheating zone is usually 100 to 150% of the length of the stretching zone, and the length of the heat setting zone is usually 50 to 50%. 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 1.3 to 2.5. When the stretching ratio is within this range, thickness unevenness in the width direction is reduced, which is preferable. Further, if necessary, if the stretching temperature is set so that the stretching temperature is made different in the width direction in the stretching zone, it becomes possible to further suppress the thickness unevenness in the width direction. In addition, W0 represents the width of the long stretched 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. 8. 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, on both sides of the long film F, gripping tool travel support tools 402 on which gripping tools (not shown) for gripping the long film F travel. The gripping tool travel support 402 is arranged so that a part thereof passes through the heating furnace 403.

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

The side wall 406 is provided along the gripping tool travel support 402 on both sides in the stretching zone 404. The side wall 406 can block the convection of the air generated by the running long film, and can prevent the movement of heat from the long film F to the extra space. Therefore, the long film F is stretched in the stretching zone in a state where there is no temperature unevenness and heat is applied sufficiently and uniformly. As a result, there is little variation in the orientation angle of the obtained long film in the width direction, and a long stretched film with stable quality can be obtained.

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 grip tool travel support tool 402 or can be provided integrally with the grip tool travel support tool 402. When the side wall 406 is installed in the vicinity of the gripping tool travel support tool 402, it is preferable to stably install the side wall 406 by fixing it to the heating furnace 403 or the installation surface of the gripping tool travel support tool 402. As described below, the side wall 406 is preferably provided integrally with the grip tool travel support tool 402 from the viewpoint of moving following the movement of the grip tool travel support tool 402.

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

That is, when the stretching angle is changed, the shape, position, and orientation of the side wall 406 may change according to the shape of the gripping tool travel support tool 402 before and after the change (hereinafter, these may be collectively referred to as the shape, etc.). Is preferred. In this way, the side wall 406 moves following the movement of the gripper travel support tool 402, whereby the shape of the side wall 406 is adjusted according to the path pattern of the gripper travel support tool after the movement. Therefore, regardless of the stretching angle, it is possible to reduce the variation in the widthwise direction of the orientation angle of the obtained long stretched film, it is possible to produce a long stretched film can be obtained stable quality long stretched film it can.

As described above, the method of causing the side wall 406 to follow the movement of the gripper travel 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 film center part (non-grip part) and both end parts (grip part). Since this temperature difference may cause film thickness unevenness and the like, it is preferable to heat or cool the tenter clip 300 with the blower 311a. On the contrary, in order to control the biting of the film 301 with respect to the tenter clip 300, heating or cooling may be performed so that the temperature of the grip portion 300a is positively different from that of the non-grip portion. The heating/cooling may be performed while the tenter clip 300 is not gripping the film 301.

As described above, the side wall 406 is provided integrally with the grip tool travel support tool 402 so that the side wall 406 can move following the movement of the grip tool travel support tool 402. The shape of the support tool 402 is changed at the same time. As a result, sufficient and uniform heat was continuously applied to the continuous film F regardless of the stretching angle, and as a result, a continuous stretched film of stable quality with little variation in the orientation angle in the width direction was obtained. sell.

The material forming the side wall 406 is not particularly limited, and the 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 may be formed by connecting a plurality of members with a hinge or the like.

Further, the surface of the side wall 406 is preferably made of a material having a heat insulating property or coated so as to prevent heat from moving 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 the side wall 406 can move following the movement of the gripper traveling support 402 when the stretching angle is changed. ..

The thickness of the side wall 406 is not particularly limited as long as it can prevent heat from entering and exiting between the long film F and the extra space. In particular, the thickness of the side wall 406 is such that when the side wall 406 moves following the movement of the gripping tool travel support 402 when the extension angle is changed, it does not hinder the bending and rotation of the side wall 406. Is preferred.

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 travel support tool 402 that passes through the stretching zone 404. Therefore, even when the stretching angle of the long film F is changed, the long film F to be stretched does not have temperature unevenness and heat is sufficiently and uniformly irrespective of changes in the volume and position of the extra space. Granted. As a result, in the obtained long stretched film, the 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 stretching zone 404, the heat from the long film F can move to the extra space in the zone where the side wall 406 is not provided. There is a nature. However, as described above, the long film F is only preheated in the preheating zone before the stretching zone and is heat-set so as not to shrink in the heat-setting zone after the stretching zone. Therefore, even if temperature unevenness occurs in the long film F in these zones, the influence on the variation of 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 sidewall 406 is provided at least in the stretching zone, it is possible to sufficiently reduce the variation in the orientation angle of the obtained long stretched film in the width direction.

Further, as another example of the manufacturing method of the present embodiment, the side wall 406 can be provided along the entire grip tool traveling support 402 installed in the heating furnace 403. In this way, by providing the side walls 406 in all zones in the heating furnace 403, the long film F traveling in the heating furnace 403 can be more reliably shielded from the heat flow 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 running long film F regardless of changes in the volume and position of the extra space. As a result, it is possible to more reliably suppress the temperature unevenness of the obtained long stretched film, and to reduce the variation of the orientation angle of the long stretched film in the width direction regardless of the stretching angle.

FIG. 8 shows only a section of the gripper travel support tool 402 in which the gripper gripping the long film F travels (hereinafter, this section may be referred to as a forward section). A section that runs after the long film F is released from gripping (hereinafter, this section may be referred to as a return section) is omitted. The gripping tool travel support tool 402 in the return path 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 travel support tool 402 in the return path section is provided in the heating furnace 403 and is provided in the vicinity of the gripping tool travel support tool 402 in the outward path section, the side wall 406 is The gripping tool travel support tool 402 in the forward path section may be provided, the gripping tool travel support tool 402 in the return path section, or the gripping tool travel support tool 402 in both sections. 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. In this way, when the gripping tool travel support tool 402 in the return path section is provided in the heating furnace 403 and in the vicinity of the gripping tool travel support tool 402 in the outward path section, By providing the gripping tool travel 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 may be wet-stretched on an unstretched film. By such wet stretching, a polymer oriented film in which polymer chains are oriented can be obtained.

Wet stretching is a general term for stretching methods in which water is used as a means for softening a film immediately before stretching, and in this case, water serves as a substantial plasticizer for the main polymer material of the film. ing. It is well known that, in order to plasticize a resin film, the film generally softens depending on the amount of the plasticizer, 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 during stretching, and how much water is contained in the film, that is, the water content is known. This is very important.

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

Considering actually the material of the film of the present invention, the water content in the polymer material of the acrylic resin film of the present invention is about 0.01% at room temperature. Usually, such an acrylic resin film (raw fabric) is stretched by raising the temperature to a glass transition temperature (Tg) so that it can be stretched. At such a Tg, for example, 130° C., the water content further decreases to 0.001 mass %. In the present invention, such a cyclic polyolefin film (raw fabric) is hydrated before stretching so that 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. %, and 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 means that the glass transition temperature (Tg) of the acrylic resin film is 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 can be performed 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 mass% was measured by immersing the acrylic resin film in a silver sealed pan (70 μl) and immersing the acrylic resin film in a temperature modulation type DSC (DSC2910 manufactured by TA Instruments). It is measured by 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 may be conditioned under constant temperature and high humidity, or these two may be used in combination. May be. When immersed in a water bath, the temperature of water is preferably in the range of 50 to 100°C, more preferably in the range of 60 to 95°C, particularly preferably in the range of 70 to 90°C. The immersion time is preferably 5 seconds to 10 minutes, more preferably 10 seconds to 8 minutes, and particularly preferably 20 seconds to 6 minutes. When the humidity is controlled with 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, particularly preferably in the range of 70 to 120°C. The relative humidity is preferably within the range of 60 to 100%.

The water used for these immersion and steam aeration should be substantially water. The term “substantially water” means that water is 60% by mass or more, and in addition to water, the following organic solvent, plasticizer, and surfactant may be included. Examples of preferable 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 during stretching may be air, water vapor, or water. When the atmosphere during stretching is in the air, it 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 fact that the atmosphere during stretching is in water vapor means that the temperature and humidity are constant or that water vapor is applied to the film. The stretching temperature is preferably 50 to 150°C, more preferably 60 to 140°C, and particularly preferably 70 to 130°C. The relative humidity is preferably in the range of 60 to 100%. By doing so, the water content in the film of the present invention, particularly in the acrylic resin, is maintained in the range of 2.0 to 20.0 mass %. When the water content is less than 2.0% by mass, the elongation at break is small at the time of stretching, the film is easily broken, and the desired retardation may not be reached.

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

When 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 Is more preferable, the range of 0.1-8.0 is more preferable, and the range of 0.1-6.0 is particularly preferable. The term "during stretching" as used herein means the aspect ratio of the film before stretching.

Maintaining the water content immediately after stretching within the range of 0.001 to 1 mass% is essential for the film to be stretched uniformly. Since the water content of the film is controlled within the range of 0.001 to 1% by mass in the zone immediately before stretching, the breaking elongation becomes small when the water content is 1.0% by mass or less, and the film has a desired thickness in front. Retardation cannot be extended 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. Further, after passing through the stretching step, water adhering to the film may be removed before reaching the winding portion. Known methods such as an air knife method and 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 winding device 519 preferably includes a winding unit 551 and further includes a tension control unit 552.

The winding unit 551 includes a rotating shaft 555, a winding core holder 556, a turret 557, a motor 558, a shift mechanism 561, and

controllers

562 and 563.

The rotary shaft 555 is arranged so that the longitudinal direction is the B direction. One end in the longitudinal direction of the rotating shaft 555 is rotatably attached to and supported by the turret 557. A motor 558 is connected to the rotating shaft 555, and the rotating shaft 555 is rotated in the circumferential direction by the motor 558. The 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 this input signal. As a result, the rotary shaft 555 rotates at the target rotation speed.

A pair of recesses extending in the longitudinal direction is formed on the outer circumference 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 cylindrical winding core 566 around which the film 527 is wound. The convex portion of the winding core 566 engages by entering the concave portion of the rotating shaft 555, 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 core holders 556 that hold the core 566 from both ends in the longitudinal direction are provided at both ends in the longitudinal direction of the rotating shaft 555. The core holder 556 is slidable in the longitudinal direction of the rotating shaft 555, and the core 566 is displaced in the B direction by sliding.

A shift mechanism 561 is connected to the core holder 556, and this shift mechanism 561 displaces the core holder 556 along the longitudinal direction of the rotating 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 receives signals of target values of the direction in which the core holder 556 should be moved in the longitudinal direction of the rotary shaft 555, the moving speed, and the amount of displacement, the core 563 is based on the input signals. Control the holder 556. As a result, the core holder 556 is displaced on the rotating rotation shaft 555 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 film conveying path for the film 527 from the second slitter 518 to the winding unit 551, and support the film so as to guide the film 527 to the winding unit 551. The

guide rollers

571 and 572 may be drive rollers having drive means, or may be so-called free rollers that rotate by contacting the film 527 being conveyed.

The dancer roller 573 is arranged between the guide roller 571 and the guide roller 572 which are arranged in the transport direction of the film 527. The film 527 is wound around the dancer roller 573 such that the film surface on the side opposite to the film surface in contact with the guide roller 571 and the guide roller 572 contacts 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. This displacement changes the tension in the longitudinal direction of the film 527. When a shift amount signal of the dancer roller 573 is input, the shift mechanism 576 displaces the dancer roller 573 by a target shift amount based on the 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 calculated based on this input signal and the calculated displacement is calculated. The quantity signal is output to the shift mechanism 576.

Note that it is preferable that the guide roller 572 on the downstream side is provided with a tension sensor (not shown) that detects 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 tension corresponding to the detection signal and the target value of the tension, and when the difference is not 0 (zero), it corresponds to the target value of the tension. The signal is output and sent to the controller 577.

The winding tip of the film 527 in the longitudinal direction is wound around the winding core 566 set in the winding unit 551, and the motor 558 is driven. The guided film 527 is wound up by driving a motor 558. While winding the guided film 527, the core holder 556 is displaced by the shift mechanism 561 in the B direction, whereby the core 566 is reciprocated in the B direction. Due to this reciprocal movement, the guided film 527 is wound around the winding core 566 while forming a roll in which the welded portion forming region 527w is displaced in the B direction. In addition, the welded portion forming 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 area formation region 527w will be described later with reference to another drawing.

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

The welded area formation region 527w will be described with reference to FIG. As described above, the casting film 539 is formed in the range extending from one side portion 533s of the band 533 to the other side portion, and therefore 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 uneven 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 raw materials for manufacturing the band 533, are welded. The welded portion 533w can be visually recognized even after post-processing such as polishing after welding.

A region of the casting film 539 formed on the weld 533w is referred to as a weld upper region 539w. Since the weld 533w can be visually identified as described above, the weld upper region 539w is identified as a region on the weld 533w.

The casting film 539 is peeled off at the peeling position PP, then transported, and 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 is stretched in the longitudinal direction, dried and contracted in the width direction, or stretched in the width direction and widened after being peeled at the peeling position PP and wound by the winding device. Or narrowed by excision.

Therefore, the width of the casting film and the film 527 are usually different. Further, the position or width W539 of the welded portion upper region 539w in the width direction of the casting film and the position or 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 part 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 the present embodiment. However, since the film 527 for a certain period of time before winding is sufficiently dried, the dimensional change is extremely small. Therefore, the film upstream of the winding position PW may be regarded as the film 527 at the time of winding. 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, the welded area 539w of the casting film at the peeling position PP is marked. In the following description, this mark will be referred to as a casting film mark, and is denoted by reference sign M539 in FIG. The marking may be performed with ink having resistance to a solvent. When the casting film mark M539 reaches the winding position PW, the area where the casting film mark M539 is located is specified as the welded portion corresponding area 527w. The mark attached to the identified welded portion corresponding region 527w is referred to as a film mark in the following description, and is denoted by reference numeral M527 in FIG.

Although FIG. 11 shows the case where the film mark M527 is larger than the casting film mark M539, the film mark M527 may be smaller or may have substantially the same size depending on the conditions of the steps after stripping. In some cases, the ratio between the width and the length in the longitudinal direction (hereinafter simply referred to as the “width-to-length ratio”) may change. However, regarding the film mark M527 and the casting film mark M539, it is not necessary to consider the size relationship or the width-length ratio relationship, 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.

Note that, in FIG. 11, for convenience of description, the widths of the welded portion 533w, the welded upper region 539w, and the welded upper formation 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. The generation of black streaks on the film roll due to this is prevented.

Further, the cycle of displacement of the winding core 566 having the amplitude in the B direction is preferably set to the time for the traveling band 533 to make one round. The time required for the band 533 to make one round is the time required for any part of the traveling band 533 to return from the specified position of the traveling path of the band 533 to the specified position, and for example, the casting position. It is the time until the part of the band 533 on the PC returns to the casting 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 the mark passes the casting position PC to the time when the mark next passes.

By setting the cycle of the displacement of the winding core 566 as the time for the traveling band 533 to make one round, the position of the welded portion formation region 527w of the film 527 has a length obtained by the time for the band 533 to make one round. As a result, a film roll having a displacement amount oscillating in the width direction can be obtained. As a result, the generation of black stripes on the film roll is more reliably prevented. Note that the displacement cycle of the winding core 566 does not have to be exactly the time for the band 533 to make one round, but a certain effect can be obtained if it is approximately equal to the time for one round.

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

The amplitude of displacement of the welded portion corresponding area 527w in the B direction may be changed according to the width W527 of the welded portion corresponding area 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 a substantially straight line extending in the longitudinal direction of the band 533. The welded portion 533w being 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 the displacement amount in the B direction.

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

In addition, 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 corresponds to the longitudinal direction as a signature. Meander to draw a curve. In this case, if the film 527 is made to synchronize with the sine curve of the welded portion corresponding region 527w in the direction in which the film 527 has the same phase, the amplitude of displacement of the welded portion corresponding region 527w in the B direction can be further suppressed. Is preferable.

The size of the film to be wound by 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 processing in the winding process. The static elimination processing will be described in detail.

FIG. 12 is a schematic view of the present invention from the drying process to the winding process, and static eliminators (blower type static eliminators) 620, 621, 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 exiting the drying chamber 605 while passing through the pass roller 604 is neutralized in the cooling chamber 607 by the neutralization device 620 while being cooled to room temperature. The static eliminator 620 directly applies the generated ions to the film 601 by a blower to eliminate the 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 a schematic view of the static elimination process of the film 601 performed in the cooling chamber 607 by the blow-type static eliminator 620. As shown in FIG. 13, the blow-type static eliminator 620 generates ions by the ion generator 620b housed in the blow head 620a, sends the air from the blower 620c through the ventilation duct 620e, and outputs the ion wind from the slit 620d. It is emitted toward the film 601. In order to measure the charging voltage of the film at the time of exiting 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, when the charge has not been eliminated to a predetermined charging potential based on the measured surface potential, the amount of ionic wind generated is controlled so that the surface potential is within an appropriate range, for example, -10 to +10V. ..

Further, the film 601 coming out of the cooling chamber 607 is destaticized by using the destaticizing device 621. Further, knurling is applied to both ends of the film 601 by embossing using a knurling roller 609. The static eliminator 621 is illustrated in FIG. 13 as an example provided on the upstream side of the knurling roller, but is not limited to that position.

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 generated amount of ionic wind is controlled based on the measured surface potential so that the surface potential is within an appropriate range, for example, in the range of −5 to +5 V, and static elimination is performed using the static elimination device 622 immediately before winding. Then, it is wound by the touch roller 612 and the winding roller 611.

Note that the static eliminators 621 to 623 perform erasing by blowing ionic wind, but static eliminators may be eliminated by various known static eliminators. In addition, a controller (not shown) is used to control each static eliminator based on the value of the surface potential measured by the surface electrometers 625 and 626 to perform more uniform static elimination. May be omitted, and static elimination may be performed simply by various static elimination devices.

The acrylic resin film according to the present invention is preferably laminated with a protective film at the time of winding.

(Protective film)
The protective film is a film that can be attached to and removed from the acrylic resin film. By sticking the protective film to the acrylic resin film, it is possible to prevent the surface of the acrylic resin film from being damaged or 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 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 that is attached to the acrylic resin film is an adhesive surface. Therefore, usually, the arithmetic average roughness Ra of the surface of the protective film, which is not the adhesive surface, falls within the above range.

According to the study by the present inventor, the arithmetic mean roughness Ra of the surface of the protective film opposite to the acrylic resin film is significantly 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 multi-layer film is overlapped, so that the surface of the multi-layer film on the acrylic resin film side and the surface of the multi-layer film on the protective film side are in contact with each other. At this time, the surface roughness of the surface of the multilayer film on the protective film side (that is, the surface roughness of the surface of the protective film on the side opposite to the acrylic resin film) is the amount of air entrapped and discharged between the multilayer films. Greatly affect

Specifically, if the surface of the surface of the multilayer film opposite to the acrylic resin film is rough, the amount of air entrained between the multilayer films at the time of winding becomes large, causing deformation and wrinkling. It will be easier. Furthermore, if the surface roughness of the surface of the multilayer film opposite to the acrylic resin film is rough, the air passage becomes large and the trapped air is easily released. Then, when the thickness of the air layer changes due to the escape of air from between the multi-layer films, the multi-layer film deforms following the change in the thickness, causing wrinkles 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 value of the above range.

On the other hand, if the surface of the multi-layer film on the side opposite to the acrylic resin film is smooth, the amount of air entrapped between the multi-layer films at the time of winding will be small, and gauge bands will easily 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 on the side opposite to the acrylic resin film to be equal to or more than the lower limit value of the above range.

The composition and layer structure 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 film having a single-layer structure having only one layer or a film having a multi-layer structure having two or more layers. The 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. When the protective film is a film having a single layer structure, it is preferable that the layer contains a polyolefin polymer. If the protective film is a film having a multilayer structure, it is preferable that at least one layer contains a polyolefin-based polymer. By using a polyolefin-based polymer, molding by co-extrusion is possible and the productivity is excellent.

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

Below, an example of suitable constituent elements of the protective film will be explained.

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

Examples of the adhesive include rubber-based adhesives, acrylic-based adhesives, polyvinyl ether-based adhesives, urethane-based adhesives, silicone-based adhesives, and the like. The pressure-sensitive adhesive may be used alone or in combination of two or more at an arbitrary ratio.

Among the adhesives, the block copolymers represented by the general formula ABA or the general formula AB (wherein A represents a styrene polymer block and B represents a butadiene polymer) Block, an isoprene polymer block, and a polymer block selected from the group consisting of olefin polymer blocks obtained by hydrogenating these). A rubber-based pressure-sensitive adhesive; 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 and 100000 or less and a glass transition temperature of 20° C. or more. Are preferred. 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 has a weight average molecular weight of 10,000 or more and 300,000 or less, and a glass transition temperature. Is preferably −20° C. or lower. Furthermore, the mass ratio of the A component and the B component (A component/B component) is preferably 5/95 or more, more preferably 10/90 or more, preferably 50/50 or less, more preferably 30/70. It is as follows.

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

Examples of acrylic adhesives include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, octyl. Alkyl (meth)acrylates such as (meth)acrylate, lauryl (meth)acrylate and stearyl (meth)acrylate; alkoxyalkyl (meth)acrylates such as methoxyethyl (meth)acrylate and butoxyethyl (meth)acrylate; cyclohexyl ( (Meth)acrylates such as (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, vinyl acetate, (meth)acrylamide, N-methylol (meth)acrylamide; Can be mentioned. In addition, (meth)acrylate means acrylate and methacrylate, and (meth)acryl means acryl and methacryl.

For the acrylic adhesive, an acrylic monomer having a functional group is preferably copolymerized and used. Examples of the acrylic monomer having a functional group include unsaturated acids such as maleic acid, fumaric acid and (meth)acrylic acid; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2 Examples thereof include hydroxyhexyl (meth)acrylate, dimethylaminoethyl methacrylate, (meth)acrylamide, N-methylol (meth)acrylamide, glycidyl (meth)acrylate, and maleic anhydride. The acrylic monomer having a functional group may be used alone or in combination of two or more at an arbitrary ratio.

The acrylic pressure-sensitive adhesive may contain a cross-linking agent if necessary. The above-mentioned cross-linking agent is a compound that undergoes a thermal cross-linking reaction with a functional group present 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 to other layers (intermediate layer, back layer, etc.) in contact with the adhesive layer in the protective film, the toughness of the protective film, the solvent resistance, the water resistance and the like. .. As the cross-linking agent, for example, an isocyanate compound, a melamine compound, a urea compound, an epoxy compound, an amino compound, an amide compound, an aziridine compound, an oxazoline compound, a silane coupling agent, and the like, and modified products thereof. You may use it suitably. The cross-linking agents may be used alone or in combination of two or more at an arbitrary ratio.

From the viewpoint of the crosslinkability and toughness of the adhesive layer, it is preferable to use an isocyanate compound or its modified product as the crosslinking agent. The isocyanate compound is a compound having two or more isocyanate groups in one molecule and is roughly classified into an aromatic compound and an aliphatic compound. Examples of the aromatic isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, naphthalene diisocyanate, tolidine diisocyanate, and paraphenylene diisocyanate. Examples of aliphatic isocyanate compounds include hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, tetramethylxylene diisocyanate, xylylene diisocyanate, and the like. Furthermore, examples of modified products of these isocyanate compounds include uret products of isocyanurate compounds, isocyanurate products, and trimethylolpropane adduct products.

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

If necessary, the adhesive layer may contain a tackifying polymer. Examples of the tackifying polymer include aromatic hydrocarbon polymers, aliphatic hydrocarbon polymers, terpene polymers, terpene phenol polymers, aromatic hydrocarbon-modified terpene polymers, chroman-indene polymers, and styrene-based polymers. Examples thereof include polymers, rosin-based polymers, phenol-based polymers, xylene polymers, etc. Among them, aliphatic hydrocarbon polymers such as low density polyethylene are preferable. However, the specific type of tackifying polymer is appropriately selected from the viewpoints of compatibility with other polymers, melting point of the resin, and adhesive strength of the adhesive layer. Further, the tackifying polymer may be used alone or in combination of two or more kinds at an arbitrary ratio.

The amount of the tackifying 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 making the amount of the tackifying polymer not less than the lower limit of the above range, it is possible to prevent the protective film from floating or peeling when it is attached to the acrylic resin film. Further, by setting the upper limit value or less, the feeding tension of the protective film is suppressed, and wrinkles and scratches at the time of bonding with the acrylic resin film are prevented, or bleeding out of the tackifying polymer is prevented and adhesion is prevented. It can keep the adhesion of the layer high.

The adhesive layer may contain additives such as a softening agent, an antioxidant, a filler, and a coloring agent (dye or pigment), if necessary. The additives may be used alone or in combination of two or more at an arbitrary ratio.

Examples of the softening agent include process oil, liquid rubber, plasticizer and the like.

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

The adhesive force 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 layer, etc.) in contact with the adhesive layer in the protective film. cm or less is preferable, and 4 N/cm or less is more preferable. 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. Also, by setting the upper limit value or less, the feeding tension of the protective film can be suppressed, and wrinkles and scratches at the time of bonding with the cyclic polyolefin film can be prevented.

The 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 film thickness of the adhesive layer to be not less than the lower limit of the above range, it is possible to increase the adhesive force and prevent the protective film from floating and peeling when the protective film is attached to the acrylic resin film. Further, when the content is not more than the upper limit value, the adhesive force can be prevented from becoming excessively high and the feeding tension of the protective film can be suppressed, so that wrinkles and scratches at the time of bonding with the acrylic resin film can be prevented. Further, since the elasticity of the protective film can be prevented from becoming too strong, the handling property 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 usually on the surface of the protective film opposite the acrylic resin film. This back layer usually does not adhere to the acrylic resin film. In the protective film including the 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.

Normally, the back layer is made of resin. The polymer contained in the resin forming the back surface layer may be a homopolymer or a copolymer. If a suitable example is given, a polyolefin polymer will be mentioned.

The polyolefin 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 thereof include polyethylene, polypropylene, ethylene-propylene copolymer, propylene-α-olefin copolymer, ethylene-α-olefin copolymer, ethylene-ethyl (meth)acrylate copolymer, ethylene-methyl (meth ) Acrylate copolymers, ethylene-n-butyl(meth)acrylate copolymers, ethylene-vinyl acetate copolymers and the like. 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 random copolymers and block copolymers. Further, examples of the α-olefin include butene-1, hexene-1, 4-methylpentene-1, octene-1, pentene-1, heptene-1 and the like.

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

The above-mentioned polymers may be used alone or in combination of two or more kinds at an arbitrary ratio. Among them, it is preferable to use a low density polyethylene in combination with a propylene-based copolymer such as an ethylene-propylene copolymer. At this time, it is particularly preferable to combine 60 to 90% by mass of the propylene copolymer and 40 to 10% by mass of low density polyethylene. As the ethylene content increases, the melting point of the ethylene-propylene copolymer can be lowered. Therefore, from the viewpoint of easy coextrusion and enabling low temperature extrusion, the ethylene content as a comonomer is preferably in the range of 3 to 7 mol %. When it is desired to add heat resistance to the back layer, the ethylene content may be reduced and the heat resistance may be appropriately selected so as to obtain desired heat resistance.

The melt flow rate of the propylene-based copolymer at 230° C. (hereinafter sometimes referred to as “MFR” as appropriate) is preferably in the range of 5 g/10 minutes to 40 g/10 minutes. Particularly, 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 layer is easily roughened by combining with low density polyethylene.

Also, it is preferable that the low-density polyethylene constituting the back layer has an MFR at 190° C. of 0.5 g/10 minutes to 5 g/10 minutes.

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 be equal to or higher than the lower limit value of this range, it is easy to adjust the surface roughness of the surface of the back layer to an appropriate range. Further, by setting the content to the upper limit or less, it is possible to prevent the resin from being detached from the protective film due to rubbing with a roll used for conveyance (for example, a metal roll, a rubber roll, etc.), and suppress generation of white powder.

The polymer contained in the back layer (for example, 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, unless significantly impairing the effects of the present invention, for example, talc, stearic acid amide, fillers such as calcium stearate, lubricants, antioxidants, ultraviolet absorbers, pigments, antistatic agents, Additives such as nucleating agents may be included. The additives may be used alone or in combination of two or more at an arbitrary ratio.

The thickness of the back layer is a ratio (adhesive layer/back layer) to the thickness of the adhesive layer, which is usually 1/40 or more, preferably 1/20 or more, and 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 pressure-sensitive adhesive layer, so that it is possible to improve the film forming property and prevent fish eyes. Further, it is possible to prevent the thickness of the back layer from being excessively thicker than that of the adhesive layer, so that 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)
If necessary, an intermediate layer may be provided between the adhesive layer and the back layer. The intermediate layer is usually formed of a resin, but it is preferable that the intermediate layer be 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, 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. The polyolefin-based polymers may be used alone or in combination of two or more at an arbitrary ratio. However, the polyolefin-based polymer contained in the intermediate layer is preferably a different type of polyolefin-based polymer from the polymers contained in the adhesive layer and the back layer.

The intermediate layer may include a material forming the adhesive layer and a material forming the back layer, if necessary. Usually, when a protective film is manufactured by a coextrusion molding method, a portion where the film thickness at the end is not uniform is slit by a slitting process or the like and discarded. By using the portion thus removed as a raw material for the intermediate layer, the amount of raw material used can be reduced.

The intermediate layer may be, 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., unless the effect of the present invention is significantly impaired. The additive may be included. The additives may be used alone or in combination of two or more at an arbitrary ratio.

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

(Method for manufacturing 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 layer, and the material of the intermediate layer as necessary.

(Ii) A method of forming an adhesive layer by preparing a back layer or an intermediate layer and applying an adhesive to the prepared layer.

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

In the manufacturing method (i) by the coextrusion molding method among the exemplified manufacturing methods, the adhesive layer and the back layer or the intermediate layer are firmly adhered to each other, and the adhesive residue on the acrylic resin film is hard to occur, and the manufacturing process Is particularly preferable because it has advantages such as low cost because it is simplified. Here, "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 polypropylene 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, etc. are usually used. Of these, from the viewpoint of avoiding adhesive residue and increase in adhesive strength over time, linear low-density polyethylene-based pressure-sensitive adhesives are often used rather than vinyl acetate-based adhesives.

Further, in the protective film produced by the production method (ii) by the coating method, polyethylene terephthalate and a polyolefin polymer are usually used as the back layer in many cases, and the adhesive layer has a rubber-based adhesive and an acrylic adhesive. Is often used. Above all, it is preferable to use polyethylene terephthalate for the back layer rather than a polyolefin polymer when foreign matters in the protective film are concerned. In addition, in the production method (ii), when the production is performed in a clean room, a high quality protective film free from foreign matter can be obtained.

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, using a shaping roll having irregularities, a nip molding method in which the protective film immediately after extrusion obtained in the coextrusion molding method is pressed to transfer the irregularities to the surface of the back layer; A method of pressing the mold film to transfer the unevenness of the mold release film, and then peeling the mold release film; a method of spraying fine particles to the surface of the back layer of the protective film to cut the surface of the back layer of the protective film; Are listed. Further, the step of deforming the surface of the back layer may be performed before or after the back layer and the adhesive layer are bonded together.

Further, irregularities may be formed on the surface of the back layer by adjusting the composition of the back layer. For example, a method of forming fine particles having a predetermined particle size in the back layer to form unevenness in the back layer; a method of forming unevenness in the back layer by adjusting the compounding ratio of materials such as resin forming the back layer, etc. Are listed.

Among the above, since it is possible to obtain a protective film having no uneven transfer of unevenness in a wide width, a nip forming method using a shaping roll having unevenness is preferable, and a protective film using a mirror-shaped roll and a shaping roll having unevenness. Is particularly preferable.

The surface material of each mirror roll and shaping roll may be, for example, metal, rubber, resin, or the like. 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 shaping roll is preferably equal to or higher than that of the mirror-finished roll. In addition, for example, the protective film may have a surface property equivalent to that of a mirror-finished roll, and the pressure of the protective film may be narrowed via a resin film softer than the shaping roll.

ㆍPreferably, the mirror surface roll and the shaping roll can control the temperature independently. The temperature of the mirror roll is preferably in the range of 40 to 160° C., and the temperature of the shaping roll is preferably in the range of 60 to 200° C. The temperature of the mirror roll is more preferably in the range of 60 to 130°C, and the temperature of the shaping roll is more preferably in the range of 80 to 180°C. By setting the temperature of the mirror-finished roll or the shaping roll to be not lower than the lower limit temperature of the above range, uneven transfer of unevenness can be prevented. In addition, by setting the temperature of the mirror-finished roll or the shaping roll to be equal to or lower than the upper limit temperature of the above range, the protective film can be prevented from being wound around the mirror-finished roll or the shaping 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 is the pressure of the protective film, the mirror surface roll and the shaping roll at the time of pressing, the roll speed, and the pressing of the protective film. The pressure at that time and the materials of the surfaces of the mirror-finished 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 roll and shaping roll temperatures are preferably (Tg-60) to (Tg+20)° C. with respect to the glass transition temperature (Tg) of the resin forming the back 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.

Also, the surface of the protective film may be printed if necessary.

(Lamination)
By laminating the acrylic resin film and the protective film, a multilayer film is obtained. 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 looseness of the acrylic resin film and the protective film. In addition, at the time of bonding, it is preferable to perform bonding while applying pressure with, for example, a nip roll.

The multi-layer film produced in this way comprises 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 optional 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 formed by winding a wide film is likely to have wrinkles or gauge bands. However, the multilayer film according to the present embodiment has such a wide width and can realize a good winding appearance when wound. Moreover, the upper limit of the width of the multilayer film is usually 2500 mm or less.

(Process of winding a multilayer film)
After obtaining the multilayer film, the multilayer 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 roller is used. Then, the acrylic resin film roll is obtained by rolling the multi-layer film around the winding roll while pressing it with a pressure roller to apply the surface pressure to the multi-layer film.

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

At this time, when the arithmetic mean roughness of the surface of the protective film on the side opposite to the acrylic resin film is Ra (μm), the pressure P (N/m) of the contact roller is expressed by 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 the multilayer film is wound, 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 changes depending on the surface roughness of the surface of the protective film opposite to the acrylic resin film. Therefore, it is preferable that the pressure P of the contact roller is set 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 greater the amount of air entrained during winding. Therefore, the pressure P of the contact roller is increased to entrain the air. Is preferably suppressed. Furthermore, if the surface roughness of the surface of the protective film opposite to the acrylic resin film is rough, the amount of air entrained at the time of winding increases, so that the amount of air entrained due to the change in the pressure P of the contact pressure roller The changes will also increase. Therefore, in the case where the surface roughness of the surface of the protective film opposite to the acrylic resin film is rough, compared with the case where the surface roughness of the surface of the protective film opposite to the acrylic resin film is smooth. The suitable range of the pressure P of the contact roller is narrowed. Therefore, the pressure P of the contact roller is within the range of the arithmetic mean roughness Ra of the surface of the protective film on the side opposite to the acrylic resin film, in the range corresponding to 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, more preferably 40 m/min or less. When the winding speed is equal to or higher than the lower limit value of the above range, the manufacturing efficiency can be increased, and when the winding speed is equal to or lower than the upper limit value, the amount of air entrained can be suppressed.

The number of windings of the acrylic resin film roll is not limited, but it 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 preferred embodiment of a method for packaging an acrylic resin film roll (roll film) and 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 body in which the roll-shaped film is wrapped with the packaging material.

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

The film 714 has at least one photocurable resin layer on its surface, as described later.

In addition, the film 714 has minute unevenness also called embossing or knurling at both end positions in the width direction, and for example, for the purpose of preventing end face deviation and winding looseness when the film is wound into a roll, the film is high. The thickness is 5 to 50 μm or the film thickness is 0.05 to 0.3.

On the other hand, the packaging material 718 is formed in a cylindrical shape, and its width dimension is formed larger than the width dimension of the film 714. The inner diameter of the packaging material 718 is formed 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. Note that 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 into a cylindrical shape, and then the edges of the packaging material 718 are attached with an adhesive tape or the like. It is good to stick and fix with.

As the packaging material 718, 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 radiation reflectance of 70% or more, and may be a metal vapor-deposited metal other than aluminum or a metal foil such as an aluminum foil. The solar radiation reflectance of the packaging material 718 is more preferably 80% or more, further preferably 90% or more. By forming the packaging body 710 of FIG. 15 using such a packaging material 718, the temperature difference inside the packaging body 710 can be suppressed within 25° C., preferably within 20° C.

Further, as the packaging material 718, it is preferable to use one having a moisture vapor transmission rate of 5.4 g/m ² ·day or less under an environment of 40° C. and 90% RH. By using the packaging material 718 having such a moisture permeability, the rate of humidity change 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 the roll-shaped film 712, and the rubber bands 720 are externally fitted to both ends thereof. Both ends of the packaging material 718 are fixed to the outer peripheral surface of the winding core 716 by the rubber band 720 in a state of being in close contact with each other. 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 packing material 718 may be fixed by being attached to the 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 diagrams 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 radiation reflectance of less than 70%). ..

In the case of a conventional package, when the package is exposed to sunlight, a temperature difference occurs between the exposed side and the non-exposed side inside the package, and a difference in humidity occurs due to the temperature difference. 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 of the film 714 in the width direction is tightly wound by the knurling (embossing) 714A, while the center is deformed because the winding is loose. It is a phenomenon, and it tends to occur as the tension at the time of winding is increased. For this reason, conventionally, it is not possible to increase the winding tension in the former processing device, and it is impossible to cope with the lengthening of the film 714 and the increase of the transport speed.

On the other hand, the packaging body of the present embodiment is packaged by the packaging material 718 having a solar reflectance of 70% or more. Therefore, even when the sunlight hits the packaging body 710, most of the sunlight is reflected by the packaging material 718 and is not absorbed by the packaging body 710. Therefore, a temperature difference and a humidity difference may occur inside the packaging body 710. It can be prevented. As a result, it is possible to prevent the film 714 from deforming and to cause a bead 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 winding 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.

Also, when winding the acrylic resin film around the core, double-sided tape, cushioning material, etc. are attached to the core. The double-sided tape is for fixing the leading end of the film to the winding core.

As shown in FIG. 17, the double-sided tape 831 has, for example, one surface (rear surface) of the strip-shaped support 831a made of PET (polyethylene terephthalate) and the first adhesive layer 831b on the winding core side on the other surface (front surface). A 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 10 to 30 μm, and more preferably 10 to 15 μm. As the double-sided tape 831, for example, Nitto Denko (model: 5601, 5603, 5605, 5606) is used. In each of the cross-sectional views of FIG. 17 and subsequent figures, it is difficult to distinguish each member such as the film 815, the double-sided tape 831, the cushioning material 832, etc. when displayed in actual dimensions. 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, the attachment will be poor, and if it exceeds 150 mm, wrinkles are likely to occur on the tape, both of which are not preferable.

The

adhesive layers

831b and 831c of the double-sided tape 831 are formed on the entire surface of the support 831a. The

adhesive layers

831b and 831c have the same composition and the same thickness, but may have different compositions and different thicknesses. Although not shown, a peeling tape is attached to the formation surface of the second adhesive layer 831c. The peeling tape is peeled off after winding the film 815 after the double-sided tape 831 is attached to the winding core 823 by the first adhesive layer 831b.

The cushioning material 832 is made of, for example, polyester or non-woven fabric, and is formed thinner than the thickness of the film 815 to be wound. Further, one having elasticity more than the double-sided tape 831 is used. The cushioning material 832 may not have an adhesive layer 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, the sticking to the winding core may be poor, and if it exceeds 30 mm, the cut image cannot be improved, which is not preferable. When the width W03 of the cushioning material 832 is determined based on the circumference length of the winding core, it is preferably 2% or less of the circumference length of the winding core.

As shown in FIG. 18, the thickness t03 of the cushioning material 832 varies depending on the number of cushioning materials used. For example, as shown in FIGS. 18 to 21 and FIG. 23 to be described later, when the number of the cushioning materials 832 and 833 is one, the thickness of the film 815 is in the range of 10 to 90%, preferably 25 to 75%. The range is more preferably 35 to 65%. If 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-out appearance decreases. When there are a plurality of cushioning materials 841 to 844, the thickness may be gradually reduced from the cushioning materials 841 to 844 near the film front end 815a. In this case, it is desirable that the difference in thickness between the cushioning materials 841 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 body 833a as in the second embodiment shown in FIG. 20, the double-sided tape 831 is not used, and the cushioning material 833 is directly attached to the winding core 823. Pasted on. In addition, in each of the following embodiments, the same constituent members are denoted by the same reference numerals, and duplicate description is omitted.

21 and 22 show the third embodiment, in which two kinds of cushioning materials 841 and 842 having different thicknesses are arranged side by side in the winding direction of the film 815. The thicknesses t12 and t22 of both the first cushioning material 841 near the tip 815a of the film 815 and the second cushioning material 842 far from the tip 815a are not more than the thickness t01 of the polymer film 15 and t12>t22. The widths W12 and W22 of the first buffer material 841 and the second buffer 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 performed in two steps as compared with the first embodiment. Can be made smaller, and the generation length of the step mark becomes shorter than that of the single 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, a cushioning material 843 having

adhesive layers

843b and 844b on at least one surface of the cushioning material 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.

Note that instead of changing the thicknesses t12 and t22 of the cushioning materials 841 to 844, the elastic modulus (Young's modulus) of each of the cushioning materials 841 to 844 may be changed, or the elastic modulus (Young's modulus) of each cushioning material 841 to 844 may be changed. The compression deformation amount of the second cushioning materials 842 and 844 moving away from the film front end 815a may be made larger than the compression deformation amount of the first cushioning materials 841 and 843. In this case, the two cushioning materials can suppress the occurrence of a step due to the influence of the leading edge of the film, and can further suppress the cut image.

The relationship between the elastic modulus and the thickness of the cushioning materials 832, 833, 841 to 844 is preferably changed according to the elastic modulus of the film 815 to be wound. 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 film thickness is tp, and when the cushioning material thickness 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 front end 815a to the cushioning material 832 is in the range of 0.1 to 20 mm, preferably 0.1 to 10 mm, and more preferably 0.1. The range is up to 8 mm. If it is less than 0.1 mm, the film 815 easily overlaps with the cushioning material 832. If it exceeds 20 mm, a step is formed between the film front end 815a and the cushioning material 832, which may cause a cut end 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 overlaps the film tip 815a, the cushioning material 832 reduces the influence of the step of the film 815 wound next. This prevents the film 815 from being extremely bent. In the same manner, the next film is wound up in the same manner, but in any case, extreme bending deformation does not occur due to the influence of the cushioning material 832, and the occurrence of cut edges is suppressed.

The sticking of the double-sided tape 831 and the adhesion of the front end of the film with the double-sided tape 831 may be performed manually or 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 cutting the film 815 and winding the film 815 around the winding core 823 during the storage. .. In the case of automatic processing, a film cutting device is used to cut the film 815 and fix it to the winding core 823. 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 front end 815a becomes a predetermined gap G01 with respect to the cushioning material 832. As described above, the leading end of the film is bonded to the second adhesive layer 831c.

Although the double-sided tape 831 and the cushioning materials 832, 833, 841 to 844 were attached to the winding core 823 in advance, the double-sided tape 831, the cushioning materials 832, 833, 841 to the film cutting drum on the film cutting device side. 844 is attached, and when the film 815 is cut by the film cutting drum, the double-sided tape 831 and the cushioning materials 832, 833, 841 to 844 are attached to the winding core 823 to wind the film 815. Good.

As shown in FIGS. 21 to 23, although the illustration is omitted, instead of changing the elastic moduli and thicknesses of the two cushioning materials 841 to 844, the first end on the side closer to the film front end 815a with respect to one cushioning material is omitted. The thickness may be gradually reduced from the edge to the second end farther from the edge. Also in this case, the film wound next by the cushioning material does not undergo extreme bending deformation, and the occurrence of cut edges is suppressed.

As shown in FIG. 24, the inclination angle θ1 of the film front end 815a with respect to the film width direction reference line BL1 is preferably in the range of −30°<θ1<30°, more preferably −20°<θ1<20°. , And more preferably −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 overlaps the film front end 815a thereafter can be reduced, and thus the cut image can be suppressed. In this way, when the tip 815a of the film 815 is cut at a predetermined inclination angle θ1, the double-sided tape 831 and the cushioning materials 832, 833, 841 to 844 have the same inclination angle according to the inclination angle θ1 of the film tip 815a. The tape is attached to the winding core 823 at θ1.

The width of the film 815 is not particularly limited, but it is preferably 600 mm or more, more preferably 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 further preferably in the range of 15 to 100 μm. The length of the film 815 is preferably 2000 m or more, 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 cylinder center direction of the winding core 823 is not particularly limited, but L2=(W01-0) mm to the width W01 of the film 815 as a reference. (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×Aa ³ /I (1)
(E: elastic modulus [MPa] of winding core, A: total mass [kg] of winding core and film, a: width of resin film [mm], I: second moment of area of winding core [mm] ⁴ ])
According to the above configuration, the winding core used in the winding step of winding the film around the winding core in a roll shape has an elastic modulus capable of suppressing flexure according to the width and winding length of the winding film. Is. Therefore, it is possible to obtain a film roll that can suppress the occurrence of back deformation of the horse even if left for a long time. Therefore, the obtained film roll can be used as a film in which the sticking of the films due to the back deformation of the horse is suppressed.

By using the acrylic resin film according to the present invention, it is possible to obtain a film roll which can be fed out and supplied with a film having a uniform thickness and in which sticking of the resin films due to back deformation of the horse is suppressed.

The present inventor presumed that the back deformation of the horse in the film roll having the film wound on the winding core is caused by the winding core or the winding core bending due to the load of the winding film or the winding core. ..

Therefore, the deflection ν of the winding core will be explained below.

The deflection ν of the winding core is generally expressed by the following equation (2), since the winding core is held while being supported by both ends of the winding core.

ν = 5ωa ⁴ /384EI (2)
(Ν: deflection of winding core [mm], ω: load per unit length of winding core [N/mm], a: width of resin film [mm], E: elastic modulus of winding core [MPa] ], I: second moment of area [mm ⁴ ] of the winding core)
In the above formula (2), the load ω per unit length of the winding core is generally expressed by the following formula (3) because the load applied to the winding core is a distributed load.

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

ν = 5Pa ³ /384EI (4)
(Ν: deflection of winding core [mm], P: load of winding core [N], a: width of resin film [mm], E: elastic modulus of winding core [MPa], I: winding core Second moment of area [mm ⁴ ])
Next, the present inventor has noticed that the deflection of the winding core differs depending on the difference in the load based on the width and the winding length of the resin film.

Therefore, first, the load P of the winding core is a value that is correlated with the total mass A of the winding core and the resin film in the state where the resin film is wound. Replaced with. Then, as a result of diligent examination of the conditions capable of sufficiently suppressing the occurrence of back deformation of the horse, the relationship of the above formula (1) was found.

Therefore, by satisfying the relationship of the above formula (1), the elastic modulus of the winding core is an elastic modulus capable of suppressing the flexure according to the width and winding length of the resin film to be wound. Therefore, even if the resin film is wound into a roll and left for a long period of time, the 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 second moment of inertia 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 based on the width and the winding length of the resin film to be wound so as to sufficiently suppress the occurrence of back deformation of the horse. Therefore, it is possible to sufficiently suppress the occurrence of back deformation of the horse without increasing the manufacturing cost of the winding core more than necessary, which is preferable. The secondary moment of area of the winding core is generally a value represented by the following formula (5). The second moment of area is a value that depends on the shape of the winding core, as can be seen from the following formula (5).

I=(d2 ⁴ −d1 ⁴ )×π/64 (5)
(D1: inner diameter [mm] of winding core, d2: outer diameter [mm] of winding core)
The winding core is not particularly limited in material as long as it has an elastic modulus within the above range. For example, it may be made of resin or metal. Among them, those having a fiber reinforced resin (FRP) layer containing a resin and fibers are preferable. Since the fiber-reinforced resin layer is a resin layer reinforced with fibers, the elastic modulus can be easily adjusted by the strength and content of the fibers contained. Therefore, the elastic modulus of the winding core can be easily adjusted within the above range. The winding core 11 including such a fiber-reinforced resin layer may be, for example, one fiber-reinforced resin layer only, or two different fiber-reinforced resin layers laminated together. It may be present, or may be a laminate of three or more different fiber reinforced resin layers. Further, it may be a laminate of a fiber-reinforced resin layer and a resin layer containing no fiber.

The shape of the winding core is preferably cylindrical. If the elastic modulus of the winding core is within the above range, it is preferable that the hollow core has a hollow shape because the weight can be reduced. It is also preferable in that the winding core can be easily attached to the rotating device. When the winding core has a cylindrical shape, the thickness of the winding core is preferably, for example, in the range of 5 to 15 mm, although it varies depending on the elastic modulus of the winding core.

Next, a method for manufacturing a winding core including the fiber reinforced resin layer as described above will be described. The method for manufacturing the winding core is not particularly limited, but the winding core can be manufactured by, for example, a filament winding method, a sheet winding method, or the like. The filament winding method is a method of forming a cylindrical fiber-reinforced resin layer by winding filamentous fibers impregnated with a liquid resin around a predetermined mold, drying or curing the resin, and then demolding. .. Further, the sheet winding method is to wind a sheet-shaped fiber (prepreg) impregnated with a liquid resin around a predetermined mold, dry or cure the resin, and then demold to form a cylindrical fiber-reinforced resin layer. Is a method of forming. More specifically, the following method is used.

FIG. 25 is a schematic diagram for explaining a method of manufacturing a winding core by the filament winding method. First, the mandrel 931 to be a mold is attached to the filament winder 932, and the resin that is the raw material of the fiber reinforced resin layer is charged into the resin tank 933. The resin here is a resin solution or a liquid resin before curing. The fibers that are the raw material of the fiber reinforced resin layer are sequentially supplied from the roller 934 around which the fibers are wound by rotating the mandrel 931 by the filament winder 932. Then, the fiber is wound around the mandrel 931 by determining the winding position by the guide 935. At that time, the fibers pass through the resin tank 933 and are 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. After that, the fiber-reinforced resin layer is formed on the mandrel by drying or curing the resin. Then, the mandrel is pulled out from the fiber reinforced resin layer to obtain the target molded body.

FIG. 26 is a schematic diagram for explaining a method of manufacturing a winding core by the 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 rotated by the rotation of the mandrel 941. Then, by rotating the mandrel 941 as a mold, the film roll (prepreg) 942 is wound around the mandrel 941 while being pressed against the mandrel 941 by the touch roller 943 as shown in FIG. After that, the fiber-reinforced resin layer is formed on the mandrel by drying or curing the resin. Then, the mandrel is pulled out from the fiber reinforced resin layer to obtain the target molded body.

As the fiber, for example, any form of fiber material such as yarn, roving, woven fabric, non-woven fabric, knitted fabric, braid and cloth can be used. Further, as the material, any fiber generally contained in the fiber reinforced resin can be used without any particular limitation. Examples thereof include glass fiber, carbon fiber, aramid fiber, and ceramic fiber. Among these, glass fibers and carbon fibers are preferable, and carbon fibers are more preferable, from the viewpoint of obtaining one having a high elastic modulus.

As the resin, any resin generally contained in fiber reinforced resins can be used without particular limitation. For example, polyester resin, unsaturated polyester resin, epoxy resin and the like can be mentioned. Of these, curable resins such as unsaturated polyester resins and epoxy resins are preferable from the viewpoint of obtaining a winding core that is stable against heat.

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 fibers and resins may be used. May be. Further, two or more fiber-impregnated fibers may be wound and then dried or cured at the same time to form two or more fiber-reinforced layers, or resin-impregnated fibers may be wound and dried or cured. After that, two or more fiber-reinforced layers may be formed by separately winding fibers impregnated with resin and drying or curing the fibers.

The method of adjusting the elastic modulus of the winding core is not particularly limited, but it can be adjusted by changing the material of the winding core. Further, in the case of a winding core having a fiber reinforced layer, as the fibers to be used, using high-strength fibers such as carbon fibers and aramid fibers, by increasing the winding amount, or by increasing the fiber content, The elastic modulus can be increased. Further, the elastic modulus can be adjusted also by the resin. Furthermore, in the case where a resin layer containing no fiber is laminated on the surface of the fiber reinforced resin layer, the elastic modulus can be adjusted also by the resin of the surface resin layer. Therefore, by appropriately adjusting the composition of the fiber-reinforced resin layer or the surface resin layer, the elastic modulus of the winding core can be adjusted within the above elastic modulus range.

(6) Slit Step In the method for producing an acrylic resin film of the present invention, it is preferable to employ a production apparatus 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 slitting device includes a disc-shaped rotating upper blade and a roll-shaped rotating lower blade.

Here, the disk-shaped rotary upper blade of the slitting device has a diameter range of 30 to 300 mm and a thickness of the cut portion of 0.3 to 3 mm, and the rotary upper blade is made of super steel It is either steel granules, 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 rotating lower blade has a roll diameter in the range of 75 to 200 mm, and the roll material of the rotating lower blade is one of super steel, super steel fine particles, SKD, and SKH.

In the manufacturing apparatus, the film slitting device may be composed of only a disc-shaped rotating upper blade. In this case, the disk-shaped rotary upper blade of the slitting device has a diameter range of 30 to 300 mm and a thickness of the cut portion of 0.3 to 3 mm, and the rotary upper blade is made of super steel, 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 velocity 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 conveying the slit end film (film fragment) to the next cutting step, for example, a mechanism for nipping and/or sucking the slit end film. Are preferred. Further, it is preferable to provide a mechanism for nipping and/or winding the slit end film.

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

Also, it is preferable to set the suction pressure in the range of −1000 to −100 Pa. Then, it is preferable to set the nip pressure within a 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 in which the transport film is covered with a masking base and then slit.

The material of the masking base 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.

Also, it is preferable to set the charge amount of the slit end film in the range of 0 to ±10 kV. Therefore, it is preferable to provide a static eliminator around the upper blade. As the static eliminator, for example, any one of a static eliminator bar, a static eliminator, and a static eliminator is used.

Edge slit film (film fragments) is preferably treated with an edge cleaner.

Also, it is preferable that the product film after slitting be treated with a web cleaner to remove the cutting 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 section.

In this heating process, first measure the film thickness with an in-line film thickness meter. Thereby, for example, the film thickness formed at both ends in the width direction to be thicker than the inside is measured. Note that the film thickness at both ends in the width direction is increased in this manner because a force pulling the resin in the width center direction acts on the resin 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, heat the film whose thickness has been measured 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. 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 is 80≦T≦Tg+50[° C.] (Tg: glass transition temperature [° C.] of resin).

　This heating is to relieve the stress generated at both ends of the film by thermal deformation. Explaining in detail, at both ends of the film formed to be thick due to the above-mentioned neck-in phenomenon, as a result of the transport tension being concentrated at the time of transport by a plurality of rollers, the force pulling the film in the width center direction (of the film A 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 longitudinal wrinkles in the longitudinal direction (conveyance direction) due to the stress and minute strain 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, it is preferable to perform this heating before the stretching step in addition to the slit step, because the above-mentioned longitudinal wrinkles and distortion can be effectively suppressed. This is because longitudinal wrinkles and distortion are emphasized by stretching the film in the longitudinal direction in the stretching step. Further, it is desirable that this heating be performed immediately after the resin is cooled and solidified by the cooling roller.

Further, if 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 if it is higher than Tg+50° C., the heated portion of the film F is The film may melt and adhere to the roller or break in the transport direction. Therefore, by setting the temperature T to 80≦T≦Tg+50 [° C.], it is possible to sufficiently heat-deform the film while preventing melting at the heated portion. However, the temperature T is more preferably 80≦T≦Tg+30 [° C.], and further 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 of the film is removed by cutting in the longitudinal direction of the film with a rotary cutter in the heating portion. By removing both end portions of the film in this cutting step, it is possible to prevent the occurrence of stress at the both end portions due to the subsequent conveyance, so that it is possible to more reliably suppress the occurrence of vertical wrinkles and distortion. 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, this cutting step may not be performed.

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

In this stretching step, while heating the film F with an IR heater, the film is conveyed by a plurality of rollers that are sequentially driven so that the peripheral speed gradually increases, so that the film is stretched in the longitudinal direction (conveying direction). To do. At this time, the rollers are driven so that the difference in peripheral speed between the rollers where the film is heated by the IR heater is the largest.

Next, wind the stretched film with the winder in the winding section.

According to the above manufacturing method, since the film before being stretched in the longitudinal direction is heated at least a part within a predetermined range from both ends in the width direction of the film, longitudinal wrinkles and strain in the longitudinal direction are stretched. Before being emphasized by, it is possible to effectively relax the stress that causes vertical wrinkles and distortion by thermally deforming the portion on which the transport tension stronger than the inner side in the width direction acts.

At this time, since at least a part of the film within the width range of 10% from both ends in the width direction is heated, the entire film is heated to cause unnecessary stretching or change in optical characteristics due to transport tension. In addition, vertical wrinkles and distortions are not generated inside the film outside the above range, and the effective width of the finished acrylic resin film is not reduced.

Further, since 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 outermost end portion of the film F formed to be the thickest and having the strongest conveyance tension acts. Do not heat. As a result, it is possible to prevent breakage of the film F due to the film F being partially stretched by heating the outermost end.

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), it is possible to prevent melting at a heated portion. The stress that causes vertical wrinkles and strain can be reliably relieved by sufficient thermal deformation.

Due to the above, it is possible to suppress the occurrence of longitudinal wrinkles and distortion in the longitudinal direction.

In addition, although the film is stretched only in the longitudinal direction (conveying direction) in the stretching step, a tenter may be provided downstream 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 a contact type or a non-contact type, but is a non-contact type using a laser or X-ray because it is easy to measure in a line. Preferably.

The heat gun does not have to heat the film with hot air, but may heat the film while contacting it with a heat roller or the like, or heat it by irradiating it with an IR heater or the like.

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

In the method for producing an acrylic resin film of the present invention, preferably, in the slitting step, a laser processing step (a step of irradiating a laser beam to process the film, hereinafter sometimes simply referred to as laser processing) is adopted. In addition, there is little damage to the film such as melting of the cut portion and defective appearance of the cut portion, and the shape of the cut portion is not disturbed even if the laser intensity changes to some extent. Further, the step of forming unevenness on both ends in the width direction of the film may be a step of processing by laser irradiation instead of the step of processing with the embossing roller on which the conventional unevenness is formed. Can be formed. Also, even if the film thickness specification changes, there is no need to replace it with an embossing roller that corresponds to the film thickness as in the past, unnecessary laser intensity is unnecessary and damage to the film such as uneven parts is less, Further, since the appropriate embossing can be easily performed by adjusting the intensity of the laser beam, the productivity of the film is excellent. Further, it is preferable to form the embossed portion at a predetermined position according to the film width by changing the irradiation position of the laser light. In this way, by varying the irradiation position of the laser beam, it becomes possible to easily form the unevenness of the embossed portion at either the end portion or the central portion in the width direction of the film. At the time of processing, there is no failure such as minute wrinkles or scratches on the film surface caused by contacting the back roller with the embossing roller for pressing, and the surface property of the film can be dramatically improved.

Further, the laser processing step is not limited to the cutting processing and the embossing processing as described above, but may be any laser processing performed during the film manufacturing process. Laser processing such as processing for roughening the surface or processing for providing grooves or 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 compounds that absorb wavelengths in this range are preferable.

Further, in the present invention, when the laser light in the laser processing step is UV light in the ultraviolet range, the compound contained in the film or coated on the film surface has a wavelength range of 0.2 to 0.4 μm. It is a compound that absorbs light. For example, as UV lasers, there are KrF excimer laser (wavelength 0.248 μm), YAG-FHG laser (wavelength 0.266 μm), YAG-THG laser (wavelength 0.355 μm), etc. Compounds that absorb are preferred.

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

The method of inclusion includes coating, spraying, etc., but other methods may be used, and the means for inclusion is not particularly limited.

The amount of the compound used can be reduced by, for example, coating the laser-irradiated portion with the compound, and the influence 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 application method or the like can be used.

By the way, laser light means “amplification of light by stimulated emission” (Light Amplification by Stimulated Emission of Radiation), and is classified into the CO ₂ laser light and the 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-processed tape wound around both ends of the film.

FIG. 27(A) is a front view of a film roll 942 in which the tape 982 having embossed or slit-shaped finishes is wound around both ends of the film and wound up. 27B is an enlarged view of a cross section of a circled portion A in FIG. 27A.

Normally, when the film is wound on the winding shaft 934, the tape 982 which is embossed or slit-processed is not wound around both ends of the base material Bo. Therefore, there is a problem that the film is damaged such as scratches due to the dust attached to the film and the winding misalignment.

As in the present invention, by embossing or slitting the tape 982 around both ends of the film Bo so as to be wound up, it is possible to prevent the film from being damaged by dust or winding misalignment. can do.

FIG. 28 is an enlarged view of the tape 982. FIG. 28A shows the tape 982 sandwiched between the film Bo and the surface of the embossed tape. FIG. 28B shows a cross section of the tape having slits and a cross section when the tape 982 is sandwiched between the film Bo and the film Bo. It is a thing.

By winding and winding the tape 982 having embossing or slit processing as shown in FIG. 28 around both ends of the film Bo, air can pass through the tape 982 having embossing processing or slit processing and the film roll 942. Air can flow in and out of the central portion of the film Bo wound as. Therefore, the air can flow in and out of the central portion of the film Bo wound up as a roll, so that it is possible to prevent the occurrence of knicks (bending, pushing marks) and wrinkles.

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

If the tape thickness X is less than 50 μm, the embossing or slit processing of the tape 982 will be crushed by the winding pressure. When the depth x of embossing or slitting is less than 20% of the thickness X of the tape, the embossing or slitting of the tape is crushed by the winding pressure, and the film is wound as a film roll 942. Air cannot flow in and out of the central part of Bo. If the depth x of embossing or slitting is greater than 50% of the thickness X of the tape, the strength of the embossed or slitted portion is weak and the processed shape is crushed by the winding pressure.

In this manner, by winding and winding the embossed or slit-processed tape 982, it is possible to prevent the film surface or the film from being damaged by dust or the like, and prevent knicks or wrinkles from occurring. can do.

The film slitting device used in the present invention preferably comprises a disk-shaped rotating upper blade and a roll-shaped rotating lower blade.

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

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

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

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.

In the present invention, it is preferable to provide a mechanism for conveying the slit end film (film fragment) to the next cutting step, for example, a mechanism for nipping and/or sucking the slit end film. Are preferred.

Furthermore, 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 value obtained by dividing the speed of the nip and/or winding film by the speed of the slit end film is 0.8 to 1.5.

Also, 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 (Knurling) Step The acrylic resin film according to the present invention preferably has embossed regions at both ends in the width direction of the film. In each embossed area, the embossing has one or more convex rows substantially parallel to the transport direction. The convex row is an area in which convex areas are formed intermittently or continuously in the transport direction. In this 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. I shall. When the convex row is an intermittent convex row, each convex area that intermittently configures the convex row is referred to as a convex area unit.

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

(I) When the embossed area has only two or more intermittent convex rows, the convex area units of each intermittent convex row are arranged so as to prevent the trapped air from being released. Control is performed between two convex area units and between any two adjacent convex rows in the width direction.

In the requirement (I), the embossed area preferably has intermittent convex rows in 2 to 7 rows, more preferably 3 to 5 rows. Specifically, for example, in FIG. 29A, the film has three intermittent convex rows A1 parallel to the transport direction (MD direction) in the embossed area A10 at one end in the width direction. When the convex row is the intermittent convex row in this way, each convex area forming the intermittent convex row is referred to as a convex area unit, and is indicated by A2 in FIG. 29A. All the convex area units A2 in all the intermittent convex rows A1 usually have the same size and are repeatedly formed at regular intervals in the transport direction.

Requirement (I): First, the placement of the convex area units is controlled between any two convex area units that are adjacent in the transport direction. Specifically, the conveyance direction distance x (mm) between any two convex area units A2 adjacent in the conveyance direction in each intermittent convex row A1 is defined as the conveyance direction length of the convex area unit A2. With respect to the thickness y (mm), it is 0.4 or less, particularly 0.01 to 0.4, and preferably 0.01 to 0.25. If the ratio is too large, the air taken up by the film roll is not effectively retained over time, so that sticking of the films, loosening of the film, wrinkles and folds cannot be sufficiently suppressed, and misalignment of the film cannot be sufficiently suppressed.

The transport direction distance x (mm) between the convex area 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 area 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.

Requirement (I) further controls the placement of the convex area units between any two adjacent convex rows in the width direction. Specifically, for any two convex rows that are adjacent in the width direction, any one convex area unit in one convex row is in the conveyance direction in the other convex row on the perspective view perpendicular to the width direction. It is arranged so as to overlap two adjacent convex area units.

Specifically, as shown in FIG. 29(B), one arbitrary convex area unit A2a has two convex area units that are adjacent to each other in the conveying direction in the adjacent convex rows on the upstream side and the downstream side in the conveying direction. It is arranged so as to overlap with A2b and A2c. FIG. 29B is a convex area unit A2c and a second convex area unit A2c that are closest to the convex area unit A2a in the adjacent intermittent convex rows A1 when paying attention to one convex area unit A2a in the film of FIG. FIG. 8 is a perspective view of a vertical cross section in the width direction showing the relationship with the convex area unit A2b close to. In such a vertical cross-sectional perspective view, if any one convex area unit overlaps only one convex area unit of the adjacent intermittent convex rows, the air entrainment of the film roll is not effectively retained over time. However, sticking between films, looseness of winding, wrinkles and folds cannot be sufficiently suppressed, and winding deviation cannot be sufficiently suppressed.

In a perspective view of a vertical cross section in the width direction, the overlapping portion of the convex area unit A2a with the convex area unit A2b on the upstream side in the conveying direction overlaps with the conveying direction length Z1 (mm) and the convex area unit A2c on the downstream side in the conveying 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 air taken up by the film roll cannot be effectively retained over time, so that sticking of the films, loosening of the film, wrinkles and folds cannot be sufficiently suppressed, and misalignment of the films cannot be sufficiently suppressed.

The above-mentioned relationship in which the convex area unit A2a overlaps with the convex area units A2b and A2c on the upstream side and the downstream side in the transport direction, respectively. This is to be satisfied between the convex area unit and the nearest convex area unit and the second closest convex area unit.

The convex area unit A2 forming the intermittent convex array A1 is lifted up at a predetermined height from the area where no convex area is formed. For example, in FIG. 29B, the convex area unit A2 (A2a, A2b, A2c) is lifted at a predetermined height h from the surface A3 of the area where the convex area is not formed. 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, and preferably 2 to 20 μm.

In the embossed area A10, the area ratio of the convex area is in the range of 20 to 80%. If the area ratio of the convex region is too small, the air taken up by the film roll cannot be effectively retained, and 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 taken up by the film roll will be too large, and the looseness of winding will be deteriorated.

The area ratio of the convex area is the ratio of the total area of the convex area unit A2 to the total area of the embossed area A10. The embossed area A10 is a minimum area divided by a straight line parallel to the transport direction so as to include all the convex areas at one end in the width direction of the film, and is an area indicated by diagonal lines in FIG. 29C, for example. is there.

The distance a between the embossed area A10 and the end surface of the film (see FIG. 29C), the width b in the width direction of the embossed area A10 (see FIG. 29C), and between the 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 10 to 20 mm.

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

In the acrylic resin film according to the present invention, the length in the width direction, the length in the transport direction, and the film thickness in the non-embossed area A5 at the center in the width direction are 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 the air that is trapped is to escape, but since the air escapes over time, problems such as loose winding, wrinkles, and folds are likely to occur, but in the present invention, such This is because even if the length is long, those problems can be effectively suppressed.

The length in the carrying 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, the larger the amount of air to be entrapped, but since the air escapes with the passage of time, problems such as loose winding, wrinkles, and folds are likely to occur. This is because even if the length is long, those problems can be effectively suppressed.

The film thickness in the non-embossed area A5 is usually in the range of 10 to 200 μm, preferably 20 to 80 μm. As the thickness is smaller, the acrylic resin film is more likely to be deformed, and therefore problems such as looseness of winding, wrinkles and folds are more likely to occur, but even such a thickness is effective in the present invention with respect to those problems. It is because it can be suppressed to.

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

Specific examples of emboss patterns when the convex area unit A2 has a rhombus shape are shown in FIGS. 30(A) to 30(C).

30A to 30C are the same as FIG. 29A to FIG. 29C except that the convex area unit A2 has a rhombus shape, and therefore description thereof will be omitted. 29A to 29C in FIGS. 30A to 30C have the same reference numerals as FIGS. 29A to 29C except that the shape of the convex area unit A2 is different. Shall have the same meaning as.

The shaded area in FIG. 30(C) is the embossed area A10.

(II) When the embossed area has one or more continuous convex rows, the embossed area may or may not have intermittent convex rows. That is, all the convex rows in the embossed region may consist of only one or more, preferably 2 to 7 rows of continuous convex examples, or 1 or more, preferably 1 to 7 continuous convex rows. It may consist of rows and one or more rows, preferably 1 to 7 rows of intermittent convex rows. As a specific example of the former case, for example, the emboss patterns shown in FIGS. 31A to 31C can be exemplified. As an embodiment of the latter case, for example, the emboss patterns shown in FIGS. 31A to 31C 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 the description thereof is omitted. To do. 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 rows are continuous. They have the same meaning.

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

Particularly 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 air that is wound into the film roll cannot be effectively retained, and 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 taken up by the film roll will be too large, and the looseness of winding will be deteriorated.

The area ratio of the convex area is the ratio of the total area of the convex area unit A2 to the total area of the embossed area A10. The embossed area A10 is a minimum area divided by a straight line parallel to the transport direction so as to include all the convex areas at one end in the width direction of the film, and is a diagonal line in FIG. 30C and FIG. 32C, for example. This is the area indicated by.

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

In the requirements of (I) and (II) described above, the acrylic resin film according to the present invention has an embossed pattern other than the intermittent convex rows and/or the continuous convex rows formed substantially parallel to the transport direction. It does not prevent that the embossed areas have the formed protruding areas or the randomly (irregularly) formed protruding areas.

In the present invention, in the knurling process for forming the embossed portion, the processing temperature of the knurling 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 embossing ring is s (seconds). ), it is preferable to perform knurling under conditions satisfying the following relational expression to produce a roll-shaped film.

0.75≦(T−Tg)×s≦1.00
The time s (second) during 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 the pressing pressure can be changed by adjusting the hardness of the rubber on the surface of the back roll made of a rubber roll or by changing the diameters of the embossing ring and the embossing back roll.

In the above, if the value of (T−Tg)×s is less than 0.75, the embossed height cannot be sufficiently obtained, and the effective knurl in the wound state becomes low, so that the sticking failure between the films may occur. Is generated, or local deformation in a convex shape occurs, and the flatness as a film is not satisfied, which is not preferable.

Also, if the value of (T-Tg) xs exceeds 1.00, the emboss height is too high, and as a result the effective knurl in the wound state is high, so the center of the winding is on the back of the horse. Such a shape is not preferable because it has a concave shape and loses the flatness of the film. When the temperature 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 increased until the value of (T−Tg)×s exceeds 1.00. A high value is not preferable because a whisker-like failure occurs.

Also, in the present invention, it is preferable to apply cold air of 10 to 20° C. to the film discharge side of the embossing/marking roller during knurling. Here, at the time of knurling, applying a cold air of 10 to 20° C. to the film discharge side of the embossing marking roller is to cool and solidify the resin portion melted by heat by cooling the film and the ring portion immediately after the embossing. Therefore, the generation of thread-like foreign matter (whisker-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 knall 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)/Coil length-Average film thickness In the above, if the effective knurl is 0.5 μm or more, sticking failure between the films does not occur and the convex shape The occurrence of local deformation is suppressed, and the flatness of the film is improved. When the effective knurl is 7.0 μm or less, the flatness of the film is improved without causing the center of the winding to be recessed into a shape like the back of a horse.

In the acrylic resin film according to the present invention, the number of beard-like foreign matters attached around the embossed portion of the roll-shaped film is preferably 0 to 50 pieces/cm ² , and 0 to 20 pieces/cm ² . It is more preferable that the amount is 0 to 10 pieces/cm ² .

In the above, it is preferable that the number of the mustache-like foreign matters attached to the periphery of the embossed portion of the film is as small as possible. If the number of the mustache-like foreign matters exceeds 50/cm ² , it is also removed by a cleaning device when processing as a polarizing plate. This is not preferable, because it becomes impossible to fill the gap and enters as a foreign substance between the polarizer and the film to cause an image defect when incorporated in a liquid crystal display device. The same applies to the case where coating processing such as antireflection treatment or antiglare treatment is applied to the surface.

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. To 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 to a range of 0.05 to 0.3 times the film thickness H, and the width W is set to a 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 based on the height required to prevent uneven adhesion between the films.On the other hand, the upper limit is higher than this, and the embossed part is too high. This is because it deforms into a polygonal shape and induces a failure.

Regarding the width of the embossed part, it is desirable to reduce it because it will eventually become a loss part. This is the required embossed part width.

However, it is also linked to the height of the embossed part, and it is necessary to set the embossed part height x the embossed part width that clears all convex, pyramid-shaped, horse back, polygonal, and winding misalignment failures.

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

The winding method is a straight winding step of winding the film around a winding core so that the side edges of the film are aligned, and after the straight winding step, the side edges are cyclic in a certain range with respect to the width direction of the film. It is preferable to have an oscillate winding step in which the film or the winding core is periodically vibrated in the width direction of the film so that the film is wound around the winding core.

In particular, when the winding length of the film reaches a predetermined switching winding length within a range of 10 to 30% with respect to the total winding length of the film, the straight winding step is switched to the oscillating winding step. Is preferred.

The film winding device includes a film winding unit that rotates a winding core to wind a film around the winding core, and an oscillator in which the film is periodically displaced on the winding core within a certain range in a width direction of the film. The oscillating portion that vibrates the film or the core in the width direction of the film by interlocking with the winding of the film so that the film is wound, and the winding length of the film reaches a predetermined switching winding length. At this time, it is preferable to include a switching unit that switches the winding of the film from the straight winding to the oscillating winding.

Explain the oscillating winding below.

As shown in FIG. 33, the film manufacturing line B10 includes a film manufacturing device B11 and a winding device B12. The film manufacturing apparatus B11 manufactures the film B13 by a solution casting method. In the solution casting method, first, a dope is prepared using raw materials. Then, the prepared dope is cast on an endless support to form a casting film. When the casting film becomes self-supporting, the casting film is peeled off from the endless support. The film B13 is formed by drying the peeled casting 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) in the width direction of the film B13 by embossing or the like. The height of the irregularities 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 portion B29. A winding motor B30, a controller B31, and a dancer section B32 are provided. The size of the film to be wound by the winding device B12 is not particularly limited, but it is preferable that the film has a total winding length in the range of 2000 to 10000 m and a width in the range of 500 to 2500 mm.

As shown in FIG. 34, the winding 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 winding shaft B19. A winding core B21 is attached to the winding shaft B19. Both ends of the winding core B21 are held by the winding core holder B20 of the winding shaft B19. The winding core holder B20 is mounted slidably in the axial direction (Y direction) of the winding shaft B19 and non-rotatably attached to the winding shaft B19. A winding motor B30 is connected to one end of the winding shaft B19, and is configured to rotate the winding 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 into a roll is obtained.

The turret B22 has a shift mechanism B28 attached to the attachment end of the winding shaft B19. The shift mechanism B28 reciprocates the core holder B20 in the axial direction on the winding shaft B19. The shift mechanism B28, the winding shaft B19, and the core holder B20 constitute an oscillating portion B29. By operating the oscillating portion B29 and causing the shift mechanism B28 to reciprocate the core holder B20 in the Y direction on the winding shaft B19, the position of the side edge B13a is within the range of the amplitude Wo each time the film B13 is laminated. It enables oscillate winding in which the film B13 is wound while being displaced inside. When the oscillating portion B29 is not operated, straight winding in which both side edges of the film B13 are aligned is possible. Switching between the straight winding and the oscillating winding is performed by the controller B31.

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

The guide rollers B23, 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 shifter B26 and the dancer roller B25 form a dancer section B32. The encoder B27 sends an encoder pulse signal to the controller B31 every time the guide roller B24 rotates at a constant rotation angle. The guide roller B24 may be provided with a tension sensor that measures the winding tension of the film B13.

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

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

The reason why the roll length at the time of switching is set in the above range is as follows. As shown in FIG. 35, a graph B50 represents 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 rotation torque of the winding core B21 and the tension of the dancer portion B32. When the rotation 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 rotation torque of the winding core B21 becomes smaller than the tension by the dancer portion B32. Will be negative. As shown in FIG. 36, in the film roll B38 in which the film B13 is wound around the winding core B21, when a force is applied from the point P1 toward the outer side in the circumferential direction, the circumference of the film B13 at the point P1 is measured. 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 in FIG. 35 is obtained in advance from a well-known stress calculation formula based on the tension at the start of winding the film B13 and the tension at the end of winding. The distribution pattern of the stress in the circumferential direction of the film B13 has various values and negative values depending on the parameters such as the thickness, width, winding length, and outer diameter of the winding core of each film and the changing situation of the winding tension pattern. It is known from the results of film winding so far that the distribution pattern is approximately the same as that of FIG. 35.

As indicated by 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, reference numeral L1 is attached to the winding length where the stress decreases from the winding length of 0 to become negative (−). Thus, at the beginning of winding, the stress in the circumferential direction sharply decreases as the winding length increases. Then, the stress in the circumferential direction further decreases and enters the negative (−) region. Note that, in FIG. 35, the winding length corresponding to the completion of winding is denoted by LE. In the negative (-) region, the stress in the circumferential direction shows the minimum value Smin. In FIG. 35, the winding length for which the stress in the circumferential direction has the minimum value Smin is denoted by Lmin. In the portion where the winding length exceeds Lmin, the stress in the circumferential direction gradually increases as the winding length increases, and enters the positive (+) region. A coil length L2 is attached to the winding length that increases and becomes positive after the stress in the circumferential direction shows the minimum value Smin. 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 of the dancer portion B32, and the film B13 is loosened. The surface pressure (surface pressure) is reduced. A graph B51 in FIG. 37 shows a change in the surface pressure at both end portions of the film B13 when the film is wound by straight winding, and a graph B52 in FIG. 38 is a graph B52 when the film is wound 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 by these graphs B51 to B53, at the beginning of winding the film B13, the decrease in the surface pressure when the film is wound in the straight winding is relatively smaller than the decrease in the surface pressure when the film is wound in the oscillate winding. The left side end of the film B13 is the left side end in the X direction, and the right side end is the right side end in the X direction.

The decrease in the surface pressure at the beginning of winding the film B13 causes loosening or misalignment of the film roll B38 after winding. Therefore, as described above, straight winding is performed while the surface pressure decreases at the beginning of winding 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 it is within the range of 10 to 30%, switching to oscillate winding. As a result, at the beginning of winding the film B13, the reduction of the surface pressure is suppressed by winding in a straight winding, and the film is wound in an oscillating winding when the stress in the circumferential direction of the film B13 leaves the negative region. Thus, 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 extension can be reduced. The winding length at the time of switching, which is obtained in advance as the timing for switching from straight winding to oscillating winding, may be obtained based on the relationship between the stress in the circumferential direction and the winding length as shown in the graph B50 as in the present embodiment. When the winding length of the film B13 reaches the switching winding length thus obtained, the controller B31 switches from straight winding to oscillating winding. The timing of switching from straight winding to oscillating winding is more preferably when the winding length is in the range of 15 to 25% with respect to the total winding length.

When the winding length is 10% or more of the total winding length, when the straight winding is switched to the oscillating winding, the surface pressure sharply decreases at the beginning of winding the film B13 as compared with the case where the winding length is less than 10%. To prevent more surely. Therefore, it is possible to more reliably prevent the film roll B38 from being loosened or misaligned. Further, when the winding length exceeds 30% with respect to the total winding length and is switched, the film is wound in a straight winding even after the film B13 has passed through the region where the stress in the circumferential direction is negative. Ear rolls are more likely to occur on the film roll B38 than when switching at this time. Therefore, by switching from the straight winding to the oscillating winding when the winding length is 30% or less with respect to the total winding length, it is possible to more reliably prevent the occurrence of ear extension than when switching is performed after the winding length exceeds 30%. ..

The switching winding length identifying unit B41 collates the winding information stored in the LUT memory B40 with the winding information input to the winding information input unit B39, and performs switching corresponding to the input winding information. Specify the time 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 the winding length measured by the winding length measuring unit B42 exceeds the switching winding length specified by the switching winding length specifying unit B41. When it is determined that the winding length exceeds the switching winding length, an oscillating winding start signal is transmitted to the oscillating unit B29. When the oscillating section B29 receives the oscillating winding start signal, the film B13 is moved while shifting the position of the side edge B13a within the range of the amplitude Wo from the straight winding that winds the film B13 so that the side edges B13a of the film are aligned. The winding of the film B13 is changed to the oscillating winding.

Next, the operation of the winding device will be described with reference to the flowchart shown in FIG. First, the winding information of the film B13 to be wound is input to the winding information input section B39. The switching-time winding length identifying unit B41 compares the winding information input to the winding information input unit B39 with the winding information stored in the LUT memory B40, and switches the winding information corresponding to the input winding information. Specify the time length.

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

The switching determination unit B43 sequentially determines whether the winding length measured by the winding length measuring unit B42 exceeds the winding length at the time of switching. When it is determined that the winding length exceeds the switching winding length, an oscillating winding start signal is transmitted from the controller B31 to the oscillating unit B29. The oscillating portion B29 that has received the oscillating winding start signal vibrates the winding core B21 at a constant amplitude Wo along the axial direction (Y direction). As a result, the winding of the film B13 is changed from the straight winding to the 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 a truck. At that time, since the inner side of the core of the film roll B38 is straightly wound, there is no looseness, and the film roll B38 is not misaligned 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 edge extension 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 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) Collection of returned materials (trimming process)
The return material recovery is a step of recovering a portion where the widthwise end portion of the film is cut while the film is conveyed in the slit step (6). For example, the end portion where the trace remains due to being gripped by the tenter in the stretching step is removed. The cutting and recovery of the end portion are usually performed at both end portions in the width direction of the film. An appropriate amount of the recovered recycled material is brought into the dissolution step, dissolved in a solvent, and provided for dope preparation.

The trimming process has an edge cutting step of cutting the edge in the film width direction and an edge collecting step of collecting the cut edge.

At the edge cutting stage, while the film is being transported in the transport direction T, the edge 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 length (width) x of the end to be cut in the width direction is not particularly limited, and specifically, such x is preferably in the range of, for example, 30 to 300 mm, particularly preferably in the range of 50 to 130 mm. ..

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

At this stage, when collecting the cut film end portion from the suction port, the conveying air is supplied from the upstream side and the downstream side in the film conveying direction toward the opening of the suction port to convey the film end portion b.・Assist the collection. The feeding speed V1 of the conveying air from the upstream side and the feeding speed V2 of the conveying air from the downstream side are each independently 100 to 6000% of the film conveying speed, preferably 500 to 5500%. And their ratio V1/V2 is less than 1, especially in the range 0.1 to 0.9, preferably in the range 0.3 to 0.9. As a result, flapping and meandering of the cut end can be suppressed, and the end can be cut and collected sufficiently smoothly.

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

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

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

The ambient 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 supply device, and the transport air from the downstream side is supplied from the downstream 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 side supply device and the opening of the suction port and the distance L2 between the supply port of the downstream side supply device and the opening of the suction port are more sufficient to prevent flapping or meandering at the cut end. From the viewpoint of suppressing the above, it is preferable that each of them is independently in the range of 20 to 200 mm, particularly in the range of 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 portion in the suction port) and the angle between the supply direction of the transport air from the downstream side and the suction direction are the same as those of the present invention. It is not particularly limited as long as the purpose is achieved, and from the viewpoint of more sufficiently suppressing flapping and meandering of the cut end, each is independently in the range of 10 to 90°, particularly in the range of 30 to 85°. It is preferable.

As the upstream supply device and the downstream supply device, those having a circular supply port are usually used.
It is preferable that the trimmed end film is quickly crushed and conveyed as a strip, and stored in a storage container for returning material recovery.
Since a cutter for crushing the returned material generally generates heat, the temperature thereof becomes high, and the acrylic resin having a low Tg is apt to be fused to the cutter blade to hinder the crushing. The cutter is preferably provided with a cooling mechanism. For example, as a cooling method thereof, a cooling medium such as dry ice may be blown together with the film.

The residual solvent amount of the film used in this step, particularly in 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 it is possible to more effectively reduce the contraction difference between the support surface side and the non-support surface side at the film end while easily cutting the film end.

(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 the 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 drawings.
FIG. 40 is a schematic view showing an example of the 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 preparation zone 310 includes a preparation tank 314, a pump 315, and a filter 316. Further, the dope 313 is uniformly prepared in the charging tank 314 by the stirring blade 317. The prepared dope 313 is sent to the casting die 320 in the band zone 311 via the pump 315 and the filter 316.
The band zone 311 is provided with a casting band 323 which is stretched around

rollers

321 and 322, and the casting band 323 is rotated by a driving device (not shown). A casting die 320 is provided on the casting band 323. The dope 313 is sent from the preparation tank 314 by the pump 315, and after the impurities are removed by the filter 316, it is sent to the casting die 320. The dope 313 is cast from the casting die 320 onto the casting band 323. The dope 313 has a 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. Note that, as is well known, the inside of the band zone 311 is divided into a plurality of chambers by partition walls as necessary, and gas is discharged and a drying gas is delivered to these chambers.

The film 325 sent from the tenter 326 to the drying zone 312 is dried while being wound around a plurality of rollers 327 and conveyed in the drying zone 312. The dried film 325 is wound up by a winding machine 328.
A gas (hereinafter, also referred to as hot air gas) 350 that is a hot air containing a solvent that has been volatilized in the drying zone 312 is processed using a solvent recovery line 331. After being sent to the heat exchanger 351, the blower 352 sends the air to the open chamber 353.
Then, by sucking the gas 350 and the atmosphere 354 from the open chamber 353 by the blower 355, the pressure (negative pressure) on the downstream side of the open chamber 353 (the blower 355 side) can be made lower than the atmospheric pressure. The form of the open chamber used in the present invention is not limited to that shown in the drawing, and any known open chamber may be used. Further, the device for bringing a part of the solvent recovery line 331 into 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 into a negative pressure.

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

Further, the gas 350 is selectively sent by a blower 355 to one of the adsorbers 359, 360, 361 by a switching valve (not shown), and the vaporized solvent contained in the gas 350 is adsorbed by the adsorbers 359, 360. , 361. 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 being exchanged with the hot air gas 350 and heated, it is further heated to a predetermined temperature by the heater 364, fed again into the drying zone 12, and reused as a dry air.

The volatile solvent components adsorbed by the adsorbers 359, 360, 361 are desorbed by the desorption gas 370 (usually steam) and sent to the condenser 371. The desorption gas 370 is condensed and liquefied in the condenser 371, and the liquid is sent to the decanter 372 as a recovery solvent. Further, the gas component which is not liquefied is again sent to the blower 355, sent to the adsorbers 359, 360 and 361, and 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 hydrophilic solvent in the distillation column 383, and the water is drained or recycled. The hydrophilic solvent is stored in the hydrophilic solvent tank 384 for reuse. The crude hydrophobic solvent has residual monomer components present in the acrylic resin and rubber particles, and it is preferable to provide a distillation column 385 to separate the residual monomer components. The hydrophobic solvent separated in the distillation column 385 is stored in a 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 refined solvent in the refined 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 preferred organic solvents used in the present invention are dichloromethane and lower alcohols. Further, methyl methacrylate is a typical one of the residual monomers of the acrylic resin. 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 mainly contains water and lower alcohol, and the lower layer mainly contains dichloromethane and methyl methacrylate. Each distillation column is designed optimally for separating water and lower alcohol, and dichloromethane and methyl methacrylate.
In order to ensure the separation of these, the decanter 372 and the

distillation columns

383 and 385 may be provided in multiple stages, or a pipe may be provided to appropriately return unripened components to the upstream process.

<<Materials that make up the acrylic resin film>>
Hereinafter, the materials used in the method for producing an 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 using an organic solvent and adding an additive to dope. The material that can be used in the present invention is not limited to the following, and known materials can be appropriately used as the constituent elements.

(1) Acrylic resin (constituent monomer species)
As the acrylic resin, any appropriate (meth)acrylic resin is adopted as long as it has 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. obtain. For example, poly(meth)acrylic acid ester such as polymethylmethacrylate, methyl methacrylate-(meth)acrylic acid copolymer, methyl methacrylate-(meth)acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester -(Meth)acrylic acid copolymer, methyl (meth)acrylate-styrene copolymer (MS resin, etc.), alicyclic hydrocarbon group-containing polymer (for example, methyl methacrylate-cyclohexyl methacrylate copolymer) , Methyl methacrylate-(meth)acrylic acid norbornyl copolymer and the like).
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 hydrogenation reaction, a removal of a protective functional group with respect to the resin. Among resins that have undergone post-reaction such as separation reaction, those having 50% or more by weight ratio of (meth)acrylic acid ester.

Examples of the monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, (meth) ) S-butyl acrylate, t-butyl (meth)acrylate, n-amyl (meth)acrylate, s-amyl (meth)acrylate, t-amyl (meth)acrylate, n-(meth)acrylate Hexyl, 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, tetrahydrofurfuryl (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 And (meth)acrylic acid esters such as methyl α-hydroxymethyl acrylate and ethyl α-hydroxymethyl acrylate.

Isobutyl methacrylate, 2-methylbutyl methacrylate, 2-ethylbutyl methacrylate, 2-isopropylbutyl methacrylate, 2-isopropyl-4-methylbutyl methacrylate, 2,3-dimethylbutyl methacrylate, 2-methylpentyl methacrylate, 2-methacryl methacrylate Acid 2-ethylpentyl, 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, 1,1-methacrylic acid 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-methacrylic acid -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-propylbutyl 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-methacrylic acid , 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-1,2-dimethylpropyl methacrylate, 1,1-diethyl-2-methylpropyl methacrylate, 1-isopropyl-1-methylbutyl methacrylate, 1-ethyl-1-methacrylate Isopropylbutyl, 1-isopropyl-1-propylbutyl methacrylate, 1-isopropyl-1,2-dimethylpropyl methacrylate, 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 methacrylate, 2-methyl-2-norbornyl methacrylate, 2-ethyl-2-norbornyl methacrylate, 2-isobornyl methacrylate, 2-methyl-2-isobornyl methacrylate, 2-ethyl-2-methacrylate Isobornyl, 8-tricyclo[5.2.1.02,6]decanyl methacrylate, 8-methyl-8-tricyclo[5.2.1.02,6]decanyl methacrylate, 8-ethyl-8-methacrylate Tricyclo[5.2.1.02,6]decanyl, 2-adamantyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 1-adamantyl methacrylate, 2-methacrylate Examples thereof include fenkill, 2-methyl-2-fenkill methacrylate, 2-ethyl-2-fenkill methacrylate, decalin-1-yl methacrylate, decalin-2-yl methacrylate and the like.

(Copolymerizable monomer)
Examples of the copolymerizable monomer include (meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; (meth)acrylic acid, crotonic acid, cinnamic acid, vinylbenzoic acid, etc. Unsaturated monocarboxylic acids; maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid and other unsaturated polycarboxylic acids; succinic acid mono(2-acryloyloxyethyl), succinic acid mono(2-methacryloyloxyethyl) Unsaturated monocarboxylic acids having a chain extension between an unsaturated group such as) and a carboxy group; unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; styrene, α-methylstyrene, α-chlorostyrene , Pt-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 methoxy polyethylene glycol vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether; N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, N-vinylacetamide, etc. -Vinyl compounds; unsaturated isocyanates such as isocyanatoethyl (meth)acrylate and allyl isocyanate; vinyl cyanides such as acrylonitrile and methacrylonitrile; and the like.

(Other acrylic resin)
An acrylic resin represented by the following general formula (E) and having an average molecular weight (Mw) in the range of 1,000 to 30,000 has high compatibility with the acrylic resin according to the present invention and is used in combination from the viewpoint of improving heat resistance. Preferably.

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 and R ₃ are H or CH ₃ , R ₂ and R ₄ are CH ₂ or C ₂ H ₄ or C ₃ H ₆ , and m and n are 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 1,000 to 30,000, it is considered to be present between the oligomer and the low molecular weight polymer.

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

-(Xa) _m -(Xb) _n- (m and n represent repeating units)
Examples of the monomer as a monomer unit constituting the compound represented by the general formula (E) are shown below, but the monomer is not limited thereto.

Examples of the ethylenically unsaturated monomer Xa include methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), and pentyl acrylate ( n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), nonyl acrylate (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-ethoxyethyl), or the like, or the above-mentioned acrylic ester as a methacrylic ester. You can list the ones that have been 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, and examples thereof include acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4 -Hydroxybutyl), acrylic acid (2-hydroxybutyl), or those obtained by replacing these acrylic acids with methacrylic acid, preferably acrylic acid (2-hydroxyethyl) and methacrylic acid (2-hydroxyethyl). ), acrylic acid (2-hydroxypropyl), and acrylic acid (3-hydroxypropyl).

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

If the molar composition ratio of Xa is high, the compatibility with the cyclic polyolefin resin improves, but the heat resistance of the film decreases. 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 formula (E) is in the range of 1,000 to 30,000, and more preferably 8,000 to 25,000.

By setting the weight average molecular weight to 1,000 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 (Used by connecting three Showa Denko KK products)
Column temperature: 25°C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (GL Science Co., Ltd.)
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 of Mw=500 to 1,000,000 was used. The 13 samples are used at substantially 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 that can make the molecular weight as uniform as possible without increasing the molecular weight too much. Examples of the polymerization method include a method using a peroxide polymerization initiator such as cumene peroxide and t-butyl hydroperoxide, a method using a larger amount of the polymerization initiator than usual polymerization, and a mercapto compound in addition to the polymerization initiator. And a method of using a chain transfer agent such as carbon tetrachloride, a method of using a polymerization terminator such as benzoquinone or dinitrobenzene in addition to the polymerization initiator, and further, JP-A-2000-128911 or 2000-344823. The compound having one thiol group and a secondary hydroxy group as described in 1 or a method of bulk polymerization using a polymerization catalyst in which the compound and an organometallic compound are used in combination can be mentioned. 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 room temperature to 130° C., preferably 50 to 100° C. 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].

(Method of measuring hydroxy value)
This measurement is based on JIS K 0070 (1992). This hydroxy number is defined as the number of mg of potassium hydroxide required to neutralize acetic acid bound to hydroxy groups when 1 g of sample is acetylated. Specifically, a sample Xg (about 1 g) is precisely weighed in a flask, and 20 ml of an acetylating reagent (prepared by adding pyridine to 20 ml of acetic anhydride to make 400 ml) is accurately added thereto. The flask is equipped with an air cooling tube and heated in a glycerin bath at 95 to 100°C.

After 1 hour and 30 minutes, cool and add 1 ml of purified water from the air cooling tube to decompose acetic anhydride 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. Further, as a blank test, titration is performed without inserting the sample, and the inflection point of the titration curve is determined.

The hydroxy value is calculated by the following formula.

Hydroxyl value={(BC)×f×28.05/X}+D
(In the formula, B is the amount of the 0.5 mol/L potassium hydroxide ethanol solution used in the blank test (ml), and C is the amount of the 0.5 mol/L potassium hydroxide ethanol solution used in the titration (ml). , F is a factor of 0.5 mol/L potassium hydroxide ethanol solution, D is an acid value, and 28.05 is 1/2 of 1 mol amount of potassium hydroxide of 56.11.
The compound represented by the general formula (E) must 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, It is particularly preferably 5 to 15% by mass.

(Method for producing acrylic resin)
As a method for producing the acrylic resin according to the present invention, for example, a commonly used polymerization method such as cast polymerization, bulk polymerization, suspension polymerization, solution polymerization, emulsion polymerization, anion polymerization and the like can be used. Among them, bulk polymerization or solution polymerization without using a suspending agent or an emulsifier is preferable because it is possible to reduce the inclusion of minute foreign matter, which is inconvenient for optical applications.

<Solution polymerization>
When carrying out solution polymerization, a solution prepared by dissolving a mixture of monomers in a solvent of aromatic hydrocarbon such as toluene or ethylbenzene can be used. When the polymerization is carried out by bulk polymerization, the polymerization can be initiated by irradiation of free radicals generated by heating or ionizing radiation, as is usually done.

As the initiator used in the polymerization reaction, any initiator used in radical polymerization can be used. For example, azo compounds such as azobisisobutylnitrile; benzoyl peroxide, lauroyl peroxide, t-butyl peroxy. An organic peroxide such as -2-ethylhexanoate can be used.

In particular, when the polymerization is carried out at a high temperature of 90° C. or higher, solution polymerization is generally used, so that the 10-hour half-life temperature is 80° C. or higher and a peroxide or azobis which is soluble in the organic solvent used. An initiator and the like are preferable. Specifically, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 1 , 1-azobis(1-cyclohexanecarbonitrile), 2-(carbamoylazo)isobutyronitrile and the like. These initiators are preferably used, for example, in the range of 0.005 to 5% by mass based on 100% by mass of the total monomers.

In the polymerization reaction, as the molecular weight modifier used as necessary, any of those generally used in radical polymerization can be used, and examples thereof include mercaptan compounds such as butyl mercaptan, octyl mercaptan, dodecyl mercaptan, and 2-ethylhexyl thioglycolate. Are particularly preferred. These molecular weight regulators are added in a concentration range such that the molecular weight of the acrylic resin is controlled within the above preferable range.

<<Bulk polymerization>>
Bulk polymerization is performed, for example, by continuously supplying a monomer component, a polymerization initiator, and the like into the reaction vessel, and continuously withdrawing a partial polymer obtained by staying in the reaction vessel for a predetermined time. Thus, the copolymer can be produced with high productivity.

The polymerization initiator used for polymerizing the monomer component is not particularly limited, and examples thereof include azo compounds such as azobisisobutyronitrile, 1,1-di(tert-butylperoxy)cyclohexane. , Benzoyl peroxide, p-chlorobenzoyl peroxide, diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, t-butylperoxypivalate, t-butylperoxy(2-ethylhexanoate), etc. Known radical polymerization initiators such as oxides can be used. As the polymerization initiator, only one kind may be used, or two or more kinds may be used in combination. Also, the amount used is usually 0.01 to 5 mass% with respect to the total amount of the mixture. The heating temperature in the thermal polymerization is usually 40 to 200° C., and the heating time is usually 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, but preferable examples include mercaptans such as n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, and 2-ethylhexyl thioglycolate. 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 in ordinary suspension polymerization can be used, and examples thereof include organic peroxides and azo compounds.
In addition, as the suspension stabilizer, a commonly used known one can be used, and examples thereof include an organic colloidal polymer substance, an inorganic colloidal polymer substance, inorganic fine particles, and a combination of these with a surfactant. it 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.
Further, in order to suppress the generation of emulsified particles in an aqueous system, a water-soluble polymerization inhibitor such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble vitamin Bs, citric acid and polyphenols may be used. Good.

Further, other suspension stabilizers may be added if necessary. For example, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and other phosphates, calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, zinc pyrophosphate, and other pyrophosphates, calcium carbonate, magnesium carbonate, calcium hydroxide. , A poorly water-soluble inorganic compound such as magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, and barium sulfate, and a dispersion stabilizer of polyvinyl alcohol.

It is also possible to use the above suspension stabilizer in combination with a surfactant such as an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, or 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 dodecylbenzenesulfonate, and alkylsulfonates. Salt, alkyl naphthalene sulfonate, alkane sulfonate, succinate, dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonate formalin condensate, polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene alkyl Examples thereof include sulfate ester salts.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl 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 polymers.

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 zwitterionic surfactants include lauryl dimethylamine oxide, and phosphoric acid ester-based or phosphorous acid ester-based surfactants. ‥

These suspension stabilizers and surfactants may be used alone or in combination of two or more, but in consideration of the diameter of particles to be obtained and the dispersion stability at the time of polymerization, selection of the suspension stabilizer or The amount used is adjusted appropriately before use. 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 0.1% with respect to 100 parts by mass of the aqueous medium. 001 to 10 parts by mass.

-Polymerization is carried out by adding the monomer mixture to the aqueous medium thus prepared.

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 homomixer, which is a disperser that utilizes force, or a method of dispersing using an ultrasonic disperser or the like.
Then, the aqueous suspension in which the monomer mixture is dispersed as spherical drops is heated to initiate polymerization. During the polymerization reaction, it is preferable to stir the aqueous suspension, and the stirring may be performed, for example, gently enough 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 can be separated as a water-containing cake by a method such as suction filtration, centrifugal dehydration, centrifugal separation, or pressure dehydration, and the obtained water-containing cake can be washed with water and dried to obtain the target particles. Here, the average particle size of the particles is adjusted by adjusting the mixing conditions of the monomer mixture and water, the addition amount of the suspension stabilizer, the surfactant and the like, 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 a raw material of the acrylic resin film according to the present invention. It is preferable that various additives described below are usually contained for the purpose of storability of monomers, control of polymerization reaction, and storability of resins.

<Polymerization initiator>
As the polymerization initiator, as described in the solution polymerization, bulk polymerization and suspension polymerization described above, those which are usually used can be used, and examples thereof include a peroxide type polymerization initiator and an azo type polymerization initiator.
Specifically, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl orthochloroperoxide, benzoyl orthomethoxyperoxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl. Peroxide polymerization initiators such as hydroperoxide and diisopropylbenzene hydroperoxide, asobisvaleronitrile, 2,2′-azobisisobutyronitrile, 2,2′-azobis(2,4-dimethylvaleronitrile) ), 2,2'-azobis(2,3-dimethylbutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,3,3-trimethylbutyro) Nitrile), 2,2'-azobis(2-isopropylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvalero) Examples thereof include azo 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, etc. are used in view of the decomposition rate of the polymerization initiator. Is preferred.
The polymerization initiator is preferably used in an amount of 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. When 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 when 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. Alkyl mercaptans such as butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimethylolpropane tris-(β-thiopropionate), pentaerythritol tetrakisthiopropionate Etc. Of these, monofunctional alkyl mercaptans such as n-octyl mercaptan and n-dodecyl mercaptan are preferred. These chain transfer agents may be used alone or in combination of two or more.

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

(Weight average molecular weight (Mw))
The acrylic resin according to the present invention has a weight average molecular weight in the range of 300,000 to 4,000,000.
The weight average molecular weight can be determined as follows.
The weight average molecular weight (Mw) of the acrylic resin according to the present invention is calculated by polystyrene conversion using gel permeation chromatography (GPC) according to the following measurement conditions.
Measuring system: "GPC system HLC-8220" manufactured by Tosoh Corporation
Developing solvent: Chloroform (Wako Pure Chemical Industries; special grade)
Solvent flow rate: 0.6 mL/min Standard sample: TSK standard polystyrene ("PS-Oligomer Kit" manufactured by Tosoh Corporation)
Measurement side column configuration: Tosoh "TSK-GEL super HZM-M 6.0x150" 2 in series connection, Tosoh "TSK-GEL super HZ-L 4.6x35" 1 reference side column configuration: Tosoh "TSK-GEL SuperH-RC 6.0x150" Two serially connected 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 a 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 (illustrated in Japanese Patent Nos. 3845109 and 4107996) is known as a method for extremely narrowing the molecular weight distribution. As a method of broadening 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)
In the acrylic resin synthesis stage, unreacted monomer components are contained in the acrylic resin as residual monomers. As a method of reducing the amount of residual monomer, it is basically necessary to increase the reaction efficiency to reduce unreacted monomer, but there is also a method of removing the residual monomer later.
In general, venting is used for devolatilization during extrusion with a high-temperature extruder, but this is not the only option, but a method of heating in an oven, and selecting an appropriate solvent to wash the acrylic resin・Methods such as drying are possible.
The amount of residual monomer in the acrylic resin is preferably in the range of 0.01 to 1% by mass, more preferably 0.01 to 0.1% by mass.

(Glass-transition temperature)
The acrylic resin according to the present invention is characterized by having a Tg (glass transition temperature) in the range of 120 to 180°C.
Due to the recent demand for high durability of optical films, durability at a temperature 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 more. It is necessary to be. The Tg of poly(methyl methacrylate), which is a typical acrylic resin, is 105 to 115° C., which is not suitable for the present invention.

(Method for adjusting glass transition temperature)
There have been efforts to increase the Tg of acrylic resins, and specific examples are shown below. Most of them are those in which a cyclic structure is partially introduced into the main chain in order to regulate 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 as the copolymer, and the glass The transition temperature (Tg) is also high, which is preferable. 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 the copolymerization with the acrylic resin in the present invention is not particularly limited, but is disclosed in JP2007-297615A, JP2007-63541A, JP2007-70607A, and JP2007-100044A. No. 2007-254726, No. 2007-254727, No. 2007-261265, No. 2007-293272, No. 2007-297619, No. 2007-316366, No. 2008-9378. , JP-A-2008-76764 and the like. These do not limit the present invention, and these may 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 in view 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) and the structure represented by JP-A-2004-168882 may be mentioned. A high polymerization yield in synthesizing the polymer before introducing the structure of the lactone ring unit, a polymer having a high content of the lactone ring structure in a high polymerization yield, a methyl methacrylate, etc. From the viewpoint of good copolymerizability with the (meth)acrylic acid ester of, the structure represented by the following general formula (2) is particularly preferable.

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 examples thereof include a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, and an —OAc group. , --CN group and the like. Moreover, 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, after the polymer having a hydroxy group and an ester group in the molecular chain is obtained by the polymerization step, the obtained polymer is heated. 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 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 as the copolymer, and the glass transition temperature (Tg) is also increased. It is preferable because it becomes high.

The maleic anhydride unit used for the copolymerization with the acrylic resin is not particularly limited, but is disclosed in JP-A-2007-113109, JP-A-2003-292714, JP-A-6-279546, and JP-A-2007-51233. JP-A-2001-270905, JP-A-2002-167694, JP-A-2000-302988, JP-A-2007-113110 and JP-A-2007-11565, and maleic acid-modified resins. Can be mentioned. However, these do not limit the present invention.
Among these, the resins described in JP-A 2007-113109 and maleic acid-modified MAS resins (methyl methacrylate-acrylonitrile-styrene copolymer, for example, Delpet 980N manufactured by Asahi Kasei Chemicals Corporation) can be preferably used. .. These do not limit the present invention, and these may be used alone or in combination of two or more. 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 acid-modified resin is not limited as long as the obtained polymer contains maleic anhydride units, and examples thereof include (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 acid copolymers, ethylene-(meth)acrylic acid-maleic anhydride copolymers, and 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 examples thereof include a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, and an —OAc group. , --CN group and the like. Moreover, the organic residue may contain an oxygen atom.
The carbon number of R ²¹ and R ²² is preferably 1-10, more preferably 1-5.

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 type>
By forming a glutaric anhydride structure in the polymer molecular chain (in the main skeleton of the polymer), high heat resistance is imparted to the acrylic resin that is a copolymer, and the glass transition temperature (Tg) Is also high, which is preferable.
The maleic anhydride unit used for copolymerization with the acrylic resin in the present invention is not particularly limited, but is disclosed in JP-A-2006-241263, JP-A-2004-70290, JP-A-2004-70296, and JP-A-2004. -126546, JP2004-163924, JP2004-291302, JP2004-292812, JP2005-314534, JP2005-326613, JP2005-331728, JP2006- 131898, JP-A 2006-134872, JP-A 2006-206881, JP-A 2006-241197, JP-A 2006-283013, JP-A 2007-118266, JP-A 2007-176982, and JP-A 2007-178504. JP-A-2007-197703, JP-A-2008-74918, WO2005/105918 and the like can be used.
Among these, more preferable is that described in JP-A-2008-74918. These do not limit the present invention, and these may 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 number of R ³¹ and R ³² is preferably 1-10, and more preferably 1-5.

Such an acrylic resin containing a glutaric anhydride unit is prepared by forming an unsaturated carboxylic acid monomer giving a glutaric anhydride unit and an unsaturated carboxylic acid alkyl ester monomer into a copolymer, It can be produced by heating the combined product in the presence or absence of a suitable catalyst to carry out an intramolecular cyclization reaction by dealcoholation and/or dehydration.

<Glutarimide type>
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 each 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 a carbon atom. (Indicates an aryl group of the numbers 6 to 10.)

The method for producing the acrylic resin having glutarimide is not particularly limited, and known methods can be applied. Specifically, using a polymethylmethacrylate or a methylmethacrylate-styrene copolymer as a raw material, an imidation step of 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 manufactured.

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

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

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

<Maleimide type>
Since the maleimide structure is formed in the polymer molecular chain (in the main skeleton of the polymer), high heat resistance is imparted to the acrylic resin as the copolymer, and the glass transition temperature (Tg) is also high. Therefore, it is preferable. As the maleimide-based structural unit, a 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. And may have a substituent on the carbon atom.

The monomer for forming the maleimide-based structural unit is not particularly limited, and examples thereof include 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 resistance to moist heat, preferably N-cyclohexylmaleimide, N-phenylmaleimide, N-methylphenylmaleimide, N-(o-chlorophenyl)maleimide, N-(m-chlorophenyl)maleimide, N-( p-chlorophenyl)maleimi is preferred, and N-cyclohexylmaleimide and N-phenylmaleimide are more preferred, and N-phenylmaleimide is more preferred, from the viewpoints of easy availability and heat resistance.

<<Styrene copolymer hydride>>
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 resin in the thermoplastic resin (B0). It is obtained by hydrogenating 70% or more of aromatic double bonds in the constitutional unit derived from a vinyl monomer.

Examples of the solvent used in the hydrogenation reaction include hydrocarbon solvents such as cyclohexane and methylcyclohexane, ester solvents such as ethyl acetate and methyl isobutyrate, ketone solvents such as acetone and methyl ethyl ketone, and ethers such as tetrahydrofuran and dioxane. Examples include system solvents, alcohol solvents 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, the hydrogen pressure may be 3 to 30 MPa, the reaction temperature may be 60 to 250° C., and the batch type or continuous flow type may be used. 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 not cleaved and the ester moiety is less hydrogenated.

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

The styrene copolymer hydride 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 aromatic double bonds remaining in the constitutional unit derived from the aromatic vinyl monomer is 30% or less, preferably less than 10%, more preferably less than 5%.

(Higher-order structure)
<Stereoregularity>
Any stereoregularity of the acrylic resin according to the present invention can be selected.
As described in JP-A-2017-48344, in the chain (diad, diad) of structural units in a polymer molecule, those having the same configuration are referred to as meso, and the opposite ones are referred to as racemo. Notated as m and r. The ratio of the two chains (triples, diad) of the chain of three consecutive structural units (triples, triad) being both racemo (denoted as rr) is syndiotactic in triplets. It is a city (rr) (hereinafter, simply referred to as “syndiotacticity (rr)”).
In the present invention, an acrylic resin having a triplet syndiotacticity (rr) of 53 to 57%, preferably 54 to 56% may be selected.
A method for producing a polymer of an unsaturated carboxylic acid or a derivative thereof disclosed in JP-A-2002-145914 by radical polymerization, which is an inexpensive method capable of effectively controlling the stereoregularity of the obtained polymer is also preferable. Can be implemented.

《Block copolymer》
As the acrylic resin according to the present invention, a block copolymer disclosed in JP-A-2018-24794 is also preferably selected. As a block structure, a block having a relatively high Tg for improving heat resistance and a block having a relatively low Tg for improving flexibility are preferable. Further, the block copolymer may form not only the entire acrylic resin according to the present invention but a resin-blended part thereof.

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 subjecting the monomers constituting each block to living polymerization is generally used. As such a living polymerization technique, for example, a method of anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt (Japanese Patent Publication No. 7-25859). A), a method of anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound (see JP-A No. 11-335432), and a method of polymerizing an organic rare earth metal complex as a polymerization initiator (special Kaihei 6-93060), a method of radical polymerization in the presence of a copper compound using an α-halogenated ester compound as an initiator (Macromol. Chem. Phys.) 201, 1108 to 1114. (2000).) and the like.
Further, using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent, a method of polymerizing the monomers constituting each block to produce a mixture containing the acrylic block copolymer according to the present invention, etc. To be Among these methods, in particular, an acrylic block copolymer can be obtained with high purity, the molecular weight and composition ratio can be easily controlled, and it is economical. A method of anionic polymerization in the presence of an aluminum compound is recommended.

《Branching structure》
A polymer having a branched structure can be selected as the acrylic resin according to the present invention. The branched structure has a repeating structural unit in a side chain in addition to the polymer main chain. A polymer having a branched structure is preferably selected for improving the physical properties because the entanglement of polymer chains increases.
As a means for introducing a branched structure into a polymer, it is general to use a macromonomer corresponding to a 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 bonding a polymerizable functional group to the end of the prepolymer (see JP-A-60-133007). Further, as the macromonomer, a commercially available product can also be used.

<<Crosslinked 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 during the polymerization of the acrylic resin. Another method is to incorporate a reactive group into the polymer side chain of an acrylic resin and crosslink the reactive groups with a crosslinking agent or by self-crosslinking.
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 polyfunctional acrylic monomers, polyfunctional allyl monomers, and mixed monomers thereof.
More specific examples include, as the polyfunctional acrylic-based monomer, ethylene oxide-modified bisphenol A di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipentaerythritol hexa Acrylate, dipentaerythritol monohydroxypentaacrylate, caprolactone modified dipentaerythritol hexaacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane triacrylate, EO modified Trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, tris(methacryloxyethyl)isocyanurate 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 monomer include, for example, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl benzene phosphonate, and mixtures thereof. Among them, triallyl cyanurate, triallyl isocyanurate and these Mixtures are preferably used.

(Birefringence (photoelastic coefficient, intrinsic birefringence))
It is preferable that the acrylic resin film according to the present invention has a low absolute value in both photoelastic coefficient and orientation birefringence (inherent birefringence). The in-plane retardation value 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 easiness of change in birefringence due to an external force, and is defined by the following equation.
CR[/Pa]=Δn/σR
Here, σR is a tensile stress [Pa], Δn is a birefringence when a stress is applied, and Δn is defined by the following equation.
Δn=n1-n2
Here, n1 is a refractive index in a direction parallel to the stretching direction, and n2 is a refractive index in a direction perpendicular to the stretching direction.

The closer the value of the photoelastic coefficient is to zero, the smaller the change in birefringence due to external force, 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) photoelastic coefficient means a monomer having a positive (negative) photoelastic coefficient of a 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 formula.
Intrinsic birefringence = npr-nvt
Here, npr is the refractive index in the direction parallel to the orientation direction of the polymer oriented with 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 means that when light is incident on a layer formed by orienting a homopolymer of the monomer with uniaxial order, the orientation direction is Is a monomer whose refractive index of light is smaller than the refractive index of light in the direction orthogonal to the alignment direction.

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

The unit (a) may be any unit as long as it is a unit derived from a monomer that satisfies the conditions 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 means 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, Nuclear alkyl-substituted styrenes such as 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene; 1,1-diphenylethylene, etc. 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 derived from a monomer that satisfies the conditions 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 means methacrylic acid, acrylic acid, and derivatives thereof, preferably methacrylic acid ester and 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, 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 alkyl acrylate unit is excellent in thermal decomposition resistance and enhances fluidity during molding. Therefore, in order to improve the thermal decomposition resistance and molding processability, it is preferable to use an acrylic acid alkyl ester as the (meth)acrylic monomer. 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 thermal decomposition resistance, and is 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, particularly, methyl acrylate and ethyl acrylate are remarkably preferable for the above-mentioned improving effect even if a small amount of them is copolymerized.
On the other hand, in order to improve heat resistance, it is preferable to use a methacrylic acid ester as the (meth)acrylic monomer.

The above (meth)acrylic monomers can 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.
Examples of the unit (c) include unsaturated dicarboxylic acid anhydride monomer units which are anhydrides such as maleic anhydride and glutaric acid; unsaturated carboxylic acid units such as lactone ring structures; N-phenylmaleimide, N- Examples thereof include maleimide units such as cyclohexylmaleimide.

The content of the unit (a), the unit (b), and the unit (c) is 5% by mass or more and less than 85% by mass, 5% by mass or more and less than 85% by mass, and 10% by mass or more and 50% by mass or less, respectively. Is preferred.
By setting the proportion of each unit constituting the copolymer (1) in such a range, the acrylic resin film according to the present invention becomes difficult to have in-plane retardation (Re), and the value of in-plane retardation. It becomes possible to control strictly.
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 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 proportions (% by mass) of the respective units (a), (b) and (c) in the copolymer (1).

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

<Cellulose ester resin>
The cellulose ester resin may be substituted with either an aliphatic acyl group or an aromatic acyl group, but it 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, specifically acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, Examples include lauroyl and stearoyl.
In the present invention, the above-mentioned aliphatic acyl group is meant to include those 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 of the above are listed.

When the cellulose ester resin is an ester with an aromatic acyl group, the number of substituents 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 on the aromatic ring is 2 or more, they may be the same or different from each other, but they may also be linked to each other to form a condensed polycyclic compound (for example, naphthalene, indene, indane, phenanthrene, quinoline). , Isoquinoline, chromene, chroman, phthalazine, acridine, indole, indoline, etc.).

In the cellulose ester resin, a structure having at least one selected from a substituted or unsubstituted aliphatic acyl group and a substituted or unsubstituted aromatic acyl group is used as the structure used in the cellulose resin according to the present invention. These may be a single acid ester or a mixed acid ester of cellulose.

Regarding 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 acetyl group substitution (ac) is 0 to 1.89. Is. More preferably, the substitution degree (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.

The cellulose ester resin 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 benzoate.
Among these, particularly preferred cellulose ester resins include 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, which has an acyl group having 2 to 4 carbon atoms as a substituent.
The moiety not substituted with an 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 are 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 the weight average molecular weight (Mw) is about 1,000,000. Those of 100,000 to 240,000 are 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 ^™ Cellulose Acetate 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 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, especially the toughness, tend to be insufficient. It tends to be bad. On the other hand, if 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, those mainly containing acetaldehyde (including paraacetaldehyde) and formaldehyde (including paraformaldehyde) are preferable, and acetaldehyde is particularly preferable, from the viewpoint of ease of production.

Examples of the aldehyde having 4 or more carbon atoms used for producing the polyvinyl acetal resin include butyraldehyde, n-octylaldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, glyoxal, glutaraldehyde, 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. Among these aldehydes, those mainly containing butyraldehyde are preferable from the viewpoint of easy production, and butyraldehyde is particularly preferable.

<Styrene resin>
In the present invention, the styrene resin means a polymer containing at least a styrene 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 examples thereof include styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4 -Nuclear alkyl-substituted styrenes such as dimethylstyrene, ethylstyrene and p-tert-butylstyrene; aromatic vinyl compound monomers such as α-alkylsubstituted styrenes such as α-methylstyrene and α-methyl-p-methylstyrene. Among them, styrene is preferable.

Styrene resin may be a homopolymer of styrene monomer or a copolymer of styrene monomer and other monomer components. Examples of the monomer component copolymerizable with the styrene-based monomer include alkyl methacrylate monomers such as methyl methacrylate, cyclohexyl methacrylate, methylphenyl methacrylate, and isopropyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate. Unsaturated carboxylic acid alkyl ester monomers such as alkyl acrylate monomers such as cyclohexyl acrylate; unsaturated carboxylic acid monomers such as methacrylic acid, acrylic acid, itaconic acid, maleic acid, fumaric acid, cinnamic acid; anhydrous Unsaturated dicarboxylic acid anhydride monomers which are anhydrides such as maleic acid, itaconic acid, ethyl maleic acid, methyl itaconic acid and chloromaleic acid; unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile; 1,3 -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. Alternatively, two or more of these may be copolymerized. The copolymerization ratio of such other monomer component is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less based on the styrene-based monomer.

As the styrene resin, a styrene-acrylonitrile copolymer, a styrene-methacrylic acid copolymer, and a styrene-maleic anhydride copolymer are particularly excellent in properties required for optical materials such as heat resistance and transparency. Therefore, it is preferable.
In the case of a 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, a copolymer having excellent transparency tends to be obtained, which is preferable.

In the case of a 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 having excellent transparency is obtained. It is preferable because a coalescence tends to be obtained.

In the case of a 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 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 50% by mass or less, the copolymer having excellent transparency is obtained. It is preferable because a polymer tends to be obtained.

(2) Rubber Particles There are various intentions of using fine particles in a film, and there are so-called matting agents that enhance the slipperiness by giving unevenness to the surface of the film, fine particles for retardation 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 acrylic resin film which is brittle and easily cracked. Although the matting agent and the rubber particles are included in the fine particles of the present invention, the rubber particles will first 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 two layers consisting of a core layer and a shell layer, a three-layer structure of core layer/intermediate layer/shell layer, or three layers of seed particle layer/core layer/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 content of rubber particles 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 multi-layer composed of a core part and a shell part obtained by further polymerizing a (meth)acrylic acid ester as a shell part to a particulate polymer forming the core part having an average particle diameter of 0.01 to 1 μm. Have 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 the by-product of foreign matter caused by aggregation of the rubber particles can be further suppressed.
Hereinafter, the shell part and the core part 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 forming the acrylic resin film.

《Core part》
The core portion is not particularly limited as long as it has a structure capable of improving the flexibility of the acrylic resin forming the acrylic resin film, and examples thereof include a structure having a crosslink. The crosslinked structure is preferably a crosslinked rubber structure.
The crosslinked rubber structure is a rubber in which a polymer having a glass transition point in the range of −100° C. to 25° C. is used as a main chain, and the main chains are crosslinked with a polyfunctional compound to give elasticity. Means the structure of. Examples of the crosslinked rubber structure include acrylic rubber, polybutadiene rubber, and olefin rubber structures (repeating structural units). Among these, acrylic rubber is preferable because it is easy to control the average particle diameter 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 the structures derived from the above-mentioned polyfunctional compounds. 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 during the production of the core part is preferably 0.01 to 15% by mass of the monomer composition used, and 0.1 to 10% by mass. It is more preferable that When the polyfunctional monomer is used within the above range, the resulting film exhibits good bending resistance.

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

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

《Monofunctional》
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 an acrylic ester and 50 to 0% by mass of another copolymerizable vinyl-based monomer, and two or more monomers per molecule are used. Those obtained by polymerizing a polyfunctional monomer having a non-conjugated reactive double bond are preferable.
The polyfunctional monomer is used in a desired amount so that the degree of crosslinking of the rubber portion is within the range of 2.3 to 4.0% by mass.
The monomers may be mixed and used, or the monomer composition may be changed and used in two or more stages.

As the acrylate ester, it is preferable to use one having 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 include octyl, phenyl acrylate, and 2-phenoxyethyl acrylate.
Two or more kinds 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, and most preferably 80 to 99% by mass in 100% by mass of the monomer mixture. .. If it is less than 50% by mass, the impact resistance tends to be low, the elongation at tensile rupture tends to be low, and cracking tends to occur when the film is cut.

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

Also, aromatic vinyls and their derivatives, and vinyl cyanides are preferable. Examples of these vinyl monomers include styrene, methylstyrene, acrylonitrile and methacrylonitrile. Other examples include unsubstituted and/or substituted maleic anhydrides, (meth)acrylamides, vinyl esters, vinylidene halides, (meth)acrylic acid and salts thereof, (hydroxyalkyl)acrylic acid esters and the like.

The multi-layer structure polymer may further have another polymer layer on the inner side (center side) of the rubber part. From the viewpoint of anti-blocking property, a monomer mixture comprising 40 to 100% by mass of an alkyl methacrylate and 60 to 0% by mass of another monomer having a double bond copolymerizable therewith, and It is preferable to have a methacrylic cross-linked polymer layer obtained by polymerizing 0.01 to 10 parts by mass of a polyfunctional monomer with respect to 100 parts by mass of the monomer mixture. As the monomer having a copolymerizable double bond, the above-mentioned other copolymerizable vinyl monomers, acrylic acid ester and the like are similarly exemplified.
The acrylic graft copolymer comprising a rubber part and a shell layer formed on the surface of the rubber part by graft polymerization is an acrylic ester rubber-like polymer particle of 5 to 90 parts by mass (more preferably 5 parts by mass). 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 (about 75 to 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 be lowered.
As the monomer used for the graft copolymerization, the above-mentioned methacrylic acid ester, acrylic acid ester, and vinyl-based monomers capable of copolymerizing these can be similarly used, and methacrylic acid ester and acrylic acid ester are preferably used. To be done. Methyl methacrylate is preferred from the viewpoint of compatibility with acrylic resins, and methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferred from the viewpoint of suppressing zipper depolymerization.

<<Multifunctional compound>>
The rubber particles having a 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, triallyl sialic acid. Nuret, triallyl isocyanurate, diallyl phthalate, diallyl maleate, divinyl adipate, divinylbenzene ethylene glycol dimethacrylate, divinylbenzene ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate -, triethylene glycol dimethacrylate, triethylene glycol diacrylate, trimethylol propane trimethacrylate, trimethylol propane triacrylate, tetramethyl methane tetramethacrylate, tetramethylol -Methane acrylate, dipropylene glycol dimethacrylate, dipropylene glycol diacrylate, etc. may be used, 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 forming the core layer is suspended or emulsion-polymerized to produce a suspension or emulsion dispersion containing rubber-like polymer particles, and then the suspension is prepared. Alternatively, a core having a multilayer structure in which a polymerizable monomer that forms a glassy polymer forming a shell layer is added to the emulsion dispersion and radically polymerized to coat the surface of the rubbery polymer particles with the glassy polymer. A method of obtaining a shell-type elastic body can be mentioned. Here, the polymerizable monomer that forms the rubber-like polymer and the polymerizable monomer that forms the glass-like polymer may be polymerized in one step or may be polymerized in two or more steps by changing the composition ratio. Good.

In order to secure the physical property 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.
A preferred structure of the core-shell type elastic body includes, for example, (a) a soft, rubber-like core layer and a hard, glass-like shell layer, wherein the core layer is a (meth)acrylic crosslinked elastic polymer. Those having a united layer, (b) those having a multilayer structure in which the rubber-like core layer has one or more glass-like layers inside thereof, and further having a glass-like shell layer outside the core layer, and the like. Can be mentioned. By appropriately selecting the monomer species of each layer, various physical properties (mechanical properties, optical properties, particularly orientation birefringence and photoelastic coefficient) of the (meth)acrylic resin can be controlled arbitrarily. The soft, rubbery layer preferably has a polymer glass transition temperature of less than 20° C., preferably less than 0° C., and the hard, glassy layer has a polymer glass transition temperature of 0° C. or more, preferably Is preferably 20° C. or higher.

As a specific example of a more preferable structure of the core-shell type rubber particles, for example, (i) the shell layer of the core-shell type rubber particles preferably contains alkyl acrylate in an amount of 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 multi-layers having different alkyl acrylate contents, and a total of alkyl acrylate. Is a non-crosslinked methacrylic resin containing 10% by mass or more, more preferably 15% by mass or more, and (iii) the core layer of the core-shell type rubber particles is an alkyl methacrylate, a polyfunctional monomer, an alkyl mercaptan. In the presence of a glassy polymer layer obtained by polymerizing a mixture of other monomers as appropriate, a multi-layer structure is formed in which a rubbery polymer layer obtained by polymerizing a mixture of acrylic acrylate, a polyfunctional monomer, an alkyl mercaptan, and other appropriate monomers is formed. And (iv) the core layer of the core-shell type rubber particles, in the presence of a glassy polymer layer polymerized by using an organic peroxide as a redox type polymerization initiator, a peracid (persulfate, Examples thereof include those having a multi-layer structure in which a rubbery polymer layer formed by polymerizing (using a superphosphate 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, still more preferably 40% by mass or less. When it exceeds 60% by mass, the dispersibility of the core/shell type rubber particles in the matrix tends to be poor, the mechanical strength and the transparency are likely to be poor, and further, foreign matter such as fish eyes is likely to occur. Also, in terms of productivity of the core/shell type rubber particles, it is easy to cause troubles such as the product tends to be coarse particles. The structural design element of such preferable core-shell type rubber particles may have only one, or two or more design elements may be used in combination. By having such a structure, the core/shell type rubber particles are easily dispersed in the acrylic resin according to the present invention easily, and there are few defects due to undispersion and aggregation when a film is formed, and strength, It is possible to obtain a film having excellent toughness, heat resistance, transparency and appearance, and suppressing whitening due to temperature change and stress, and having excellent quality.

When the core/shell type rubber particles of the present invention are produced by emulsion polymerization, suspension polymerization, etc., a known polymerization initiator can be used. Particularly preferred polymerization initiators are potassium persulfate, ammonium persulfate, persulfates such as ammonium persulfate, perphosphates such as sodium perphosphate, organic azo compounds such as azobisisobutyronitrile, cumene hydroperoxide. , Tertiary butyl hydroperoxide, hydroperoxide compounds such as 1,1 dimethyl-2hydroxyethyl hydroperoxide, tertiary butyl isopropyloxy carbonate, peresters such as 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 selected appropriately 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, for example, sodium alkyl sulfonate, sodium alkylbenzene sulfonate, sodium dioctyl sulfosuccinate, sodium lauryl sulfate, sodium fatty acid, anionic salts such as sodium phosphate ester of polyoxyethylene lauryl ether phosphate. Surfactants and nonionic surfactants such as alkylphenols, reaction products of aliphatic alcohols with 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 sodium polyoxyethylene lauryl ether 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, coagulates a polymer component by adding an electrolyte or an organic solvent as a coagulant to the latex, and heats appropriately. The polymer content is dried by carrying out operations such as washing and separation of the aqueous phase to obtain lump or powder core/shell type rubber particles.

As the coagulant, known ones such as a water-soluble electrolyte and an organic solvent can be used, but from the viewpoint of improving the thermal stability during molding of the obtained copolymer and from the viewpoint of productivity, magnesium chloride or sulfuric acid is 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 difference in refractive index between the rubber particles and the acrylic resin (also referred to as matrix resin) constituting the film is preferably 0.015 or less, more preferably 0.012 or less, and further preferably 0.01 or less. .. When the difference in refractive index from the matrix resin is 0.015 or less, a film having excellent transparency can be obtained. As a method for satisfying the above refractive index condition, a method of adjusting a unit composition ratio of each monomer of the matrix resin, and/or a composition of a polymer and/or a monomer used for each layer of rubber particles 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, regarding rubber particles, the rubber particles are press-molded, the average refractive index of the molded body is measured by a laser refractometer, and the value is taken as the refractive index of the rubber particles.
Similarly, for the matrix resin, a material (resin or resin composition) forming the matrix resin is molded, the average refractive index of the molded body is measured by a laser refractometer, and the value is defined as the refractive index of the matrix resin. To do.
The refractive index difference 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 addition, in the present embodiment, the refractive index means a refractive index with respect to light having a wavelength of 550 nm at 23° C.

《Temperature dependence》
The difference in the refractive index between the matrix resin and the rubber particles is preferably as low as possible in the range of 0 to 50°C. For that purpose, it is preferable that the matrix resin and the rubber particles have the same refractive index temperature dependence.

(Birefringence)
The acrylic resin film according to the present invention may be in a polymer orientation state by 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 do not exhibit birefringence due to orientation or stress.
For example, a graft copolymer 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. Polymers are also preferably used as the rubber particles according to the present invention.

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

Examples of specific monomers to be referred to in setting the photoelastic constant of the polymer are shown below, but the present invention is not limited thereto. (The value in [] is the photoelastic constant of the corresponding homopolymer)
Monomers that exhibit positive photoelastic birefringence:
Benzyl methacrylate [48.4×10-12Pa-1]
Dicyclopentanyl methacrylate [6.7×10-12 Pa-1]
Styrene [10.1×10-12Pa-1]
Parachlorostyrene [29.0 x 10-12 Pa-1
Monomers 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 x 10-12 Pa-1]
Isobornyl methacrylate [-5.8×10-12Pa-1]
It is known that the photoelastic constant of the copolymer has additivity with the photoelastic constant of each homopolymer corresponding to the monomer species used for the copolymerization. For example, regarding a binary copolymerization system of methyl methacrylate (MMA) and benzyl methacrylate (BzMA), it is reported that the photoelastic birefringence becomes almost zero at poly-MMA/BzMA=92/8 (wt %). ing. The same applies to a mixture (alloy) of two or more kinds of polymers, and the additivity is established with the photoelastic constant of each polymer. From the above, in order to reduce the photoelastic birefringence of the optical resin material and the optical film of the present invention, the photoelastic constant of the homopolymer of the monomer that constitutes the rubber particles is lowered, and the compounding amount (wt) is set. %) must be adjusted.

Also, it is known that the orientation birefringence of a copolymer polymer has an additivity with the intrinsic birefringence of each homopolymer corresponding to the monomer species used for the copolymerization. The same applies to a mixture (alloy) of two or more kinds of polymers, and the additivity is established with the intrinsic birefringence of each polymer. Regarding the monomer species suitable for reducing the orientation birefringence of the homopolymer itself of the monomer constituting the rubber particles, monomer species having different orientation birefringence may be used in combination.

[Examples] Specific examples of specific monomers (specific birefringence of homopolymers composed of the monomers) that are helpful in setting the orientation birefringence of the polymer are described below, but the present invention is not limited thereto. The intrinsic birefringence is birefringence (orientation birefringence) when the polymer is perfectly oriented in one direction.

Polymers showing positive intrinsic birefringence:
Polybenzyl methacrylate [+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 on the photoelastic constant and orientation birefringence of some polymers have been described above. However, depending on the polymer, the orientation birefringence is "positive" and the photoelastic constant is "negative". Not necessarily. Table I below shows examples of the signs of orientation birefringence and 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 the birefringence (constant) becomes almost zero.

As a preferable example of the polymer composition for making both the photoelastic birefringence and the orientation birefringence extremely small and ideally making both of them substantially zero, poly(MMA/3FMA/BzMA=55) described in Japanese Patent No. 4624845. 0.5/38.0/6.5). However, since this polymer composition is composed only of methacrylic acid ester-based monomers, in high temperature molding, zipper depolymerization occurs and the molecular weight decreases, which causes problems such as reduction in mechanical strength, coloring, and foaming. .. As a solution to this problem, copolymerization of a small amount of acrylic acid ester can be mentioned, and it becomes possible to suppress excessive decomposition due to zipper depolymerization during high temperature molding.

There is no particular limitation on the composition of the homopolymer of the monomers constituting the rubber particles. Among them, monomers that can be particularly preferably used include, for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, glycidyl methacrylate, epoxycyclohexyl methacrylate. Methyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dicyclopentanyl methacrylate, dicyclopentenyloxyethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,2-trichloroethyl Methacrylic acid esters such as methacrylate, isobornyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, pentamethylpiperidinyl methacrylate, tetramethylpiperidinyl methacrylate, tetrahydrofurfuryl methacrylate; methyl acrylate, ethyl acrylate , Butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, epoxycyclohexylmethyl acrylate, benzyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dicyclopentanyl acrylate, dicycloacrylate Acrylic esters such as pentenyloxyethyl, phenyl acrylate, phenoxyethyl acrylate, pentamethylpiperidinyl acrylate, tetramethylpiperidinyl acrylate, tetrahydrofurfuryl acrylate; carboxylic acids such as methacrylic acid and acrylic acid And their esters; unsubstituted and/or substituted maleic anhydride, citraconic anhydride, dimethyl maleic anhydride, dichloromaleic anhydride, bromomaleic anhydride, dibromomaleic anhydride, phenylmaleic anhydride, diphenylmaleic anhydride, etc. Maleic anhydride; 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 cyanes such as acrylonitonyl and methacrylonitrile; vinyl arenes such as styrene, α-methylstyrene, monochlorostyrene, dichlorostyrene; maleic acid, fumaric acid And their esters; vinyl halides such as vinyl chloride, vinyl bromide, chloroprene; vinegar Vinyl acetate; alkenes such as ethylene, propylene, butylene, butadiene and isobutylene; halogenated alkenes; allyl methacrylate, diallyl phthalate, triallyl cyanurate, monoethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate , And polyfunctional monomers such as divinylbenzene. These vinyl monomers can be used alone or in combination of two or more kinds. Particularly, from the viewpoint of controlling birefringence, it is preferable to use a polyfunctional monomer to such an extent that the polymer chains can be oriented with respect to stress, but it is particularly preferable not to use a polyfunctional monomer.

Among the above monomers, from the viewpoint of reducing the birefringence, a vinyl-based monomer having a ring structure such as an alicyclic structure, a heterocyclic structure or an aromatic group in the molecular structure is preferable, and among them, It is more preferable to contain a vinyl-based monomer having an alicyclic structure, a heterocyclic structure or an aromatic group. 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 arenes such as styrene, α-methylstyrene, monochlorostyrene and dichlorostyrene, or benzyl (meth)acrylate, phenyl (meth)acrylate, (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, its ring structure is preferably a polycyclic structure, 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. Examples of the substituent which R ⁹ and R ¹⁰ may have include halogen, hydroxy group, carboxy group, alkoxy group, carbonyl group (ketone structure), amino group, amide group, epoxy group, carbon-carbon group. And at least one selected from the group consisting of a double bond, an ester group (a derivative of a carboxy group), a mercapto group, a sulfonyl group, a sulfone group, and a nitro group. Among them, at least one selected from the group consisting of halogen, hydroxy group, carboxy group, alkoxy group, and 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 in which R ⁹ is a hydrogen atom or a substituted or unsubstituted linear or branched C 1 alkyl group. In the above formula (4c), R ¹⁰ is preferably 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, A (meth)acrylate-based monomer having a cyclic structure is more preferable. Further, in the formula (4c), l is an integer of 1 to 2, and n is an integer of 0 to 2, and is 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.

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, based on 100% by mass of the homopolymer of the monomer constituting the rubber particles. %, and even more preferably 1 to 50% by mass.

The homopolymers of the monomers constituting the rubber particles may be mixed and polymerized in one stage. If the birefringence of the molded product composed of the polymer obtained by polymerizing the homopolymer of the monomer 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 the rubber particles, only the rubber particles are separately molded in the same manner as in the measurement of the refractive index to prepare a plate-shaped or film-shaped sample. Ordinary birefringence measurement may be performed using this sample.

(Particle size)
The core/shell type rubber particles preferably have a particle diameter of the soft core layer of 1 to 500 nm, more preferably 10 to 400 nm, and further preferably 50 to 300 nm. , 70 to 300 nm is particularly preferable.
If the particle diameter 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 more than 500 nm, the (meth)acrylic resin Heat resistance and transparency may be impaired.

Here, the particle size is obtained by, for example, a dynamic light scattering method using MICROTRAC UPA150 (manufactured by Nikkiso Co., Ltd.), or by a turbidity method in which the permeation rate of the polymerization solution per unit weight is measured using a turbidimeter. You can ask. 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 Co., Ltd.) in a weight ratio of 20:80 was used as a transmission electron microscope (manufactured by JEOL Ltd.). (JEM-1200EX), it is also possible to take an image with an acceleration voltage of 80 kV by a RuO4 stained ultrathin section method, randomly select 100 rubber particle images from the obtained photographs, and obtain the average value of those particle diameters. ..

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

The rubber particle dispersion contains rubber particle powder as a raw material and an organic solvent as main components. The organic solvent that can be used is not particularly limited as long as the rubber particles are dispersed and a dispersion can be prepared.
The organic solvent used in the present invention is, for example, a chlorine-based solvent such as dichloromethane or chloroform, a solvent selected from chain hydrocarbons having 3 to 12 carbon atoms, cyclic hydrocarbons, aromatic hydrocarbons, esters, ketones and ethers. Is preferred. The ester, ketone and ether may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, decane and the like. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane, decalin and derivatives thereof. Examples of the aromatic hydrocarbon having 3 to 12 carbon atoms include benzene, toluene and xylene. Examples of the ester 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 phenetole.

Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. As the organic solvent used in the method for preparing a rubber particle dispersion 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 at 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 dope. From the viewpoint of dispersibility of rubber particles, hydrophilic organic solvents such as methanol and ethanol are preferably used.
Due to the dispersibility of rubber particles, various conventional 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 kind may be newly added, or a dispersant of another kind may be further 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 is preferably a relatively low molecular weight one having a molecular weight of 1,000 to 100,000. When a high molecular weight acrylic resin is used as a dispersant, it may cause cross-linking aggregation and induce aggregation of rubber particles.
The content of 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 amount of the necessary rubber particles, and the degree of dilution of the dope after the addition is high, which is not preferable. A high content is not preferable because the dispersion stability of the rubber particle dispersion becomes low. A more preferable content is 5 to 20%.

In preparing the rubber particle dispersion according to the present invention, it is preferable that the dispersion treatment is performed within 0.1 second to 1 minute after the raw material powder of the rubber particles and the organic solvent are mixed. Furthermore, the dispersion treatment is preferably an inline treatment rather than a batch treatment, and the dispersion liquid dispersed by the inline treatment is preferably added to the dope as it is without stagnation.
Conversely, 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, rubber particles tend to agglomerate during the storage period to increase the viscosity of the dispersion liquid, and therefore it is preferable to constantly stir and maintain the flow during the storage period.
When the organic solvent contains methylene chloride as a main component, its specific gravity is large, so that the rubber particles are difficult to mix well and a step may be generated. Therefore, it is preferable that the first mixing state is not a mixture of a large amount of rubber particle powder and a large amount of an organic solvent, but a small amount of each other. That is, it is preferable to use in-line mixing in which the rubber particle powder and the organic solvent are weighed and provided online, first mixed in a small space of about 0.1 to 10 L, and then sequentially fed to the disperser. Examples of the in-line mixing device include a flow jet mixer continuous injection mixer manufactured by Koken Powtex Co., Ltd., and an in-line circulation type solid-liquid mixing/dispersing device CMX manufactured by IKA.

A normal disperser can be used as the disperser for dispersing the rubber particles. Dispersers are roughly classified into media dispersers and medialess dispersers. Examples of the media disperser include a ball mill, a sand mill and a dyno mill. As the medialess disperser, there are an ultrasonic type, a centrifugal type, a high pressure type, and the like. In the present invention, a high pressure dispersing device is preferable.

The high-pressure dispersing device is a device that creates special conditions such as high shear and high-pressure state by passing a composition obtained by mixing fine particles and a solvent at high speed through a thin tube. It is preferable that the maximum pressure condition inside the apparatus is 9.8×10 ² N or more in a thin tube having a tube diameter of 1 to 2000 μm by processing with a high-pressure dispersion apparatus. More preferably, it is 1.96×10 ³ N or more. At that time, it is preferable that the maximum reaching speed is 100 m/sec or more and the heat transfer speed is 100 kcal/hr or more.
The high-pressure disperser as described above includes an ultrahigh-pressure homogenizer manufactured by Microfluidics Corporation (2 brand name: Microfluidizer) or Nanomizer manufactured by Nanomizer, or Ultra Turrax. Examples include Food Machinery homogenizer, Sanwa Machinery Co., Ltd., product number UHN-01.
It is also preferable to connect a plurality of these dispersers in series or in parallel for in-line processing. For example, before introducing the admixture treated with a flow jet mixer into a Manton-Gorlin type high-pressure disperser, some dispersion treatment should be performed in advance with an emulsifying disperser (eg, Milder made by Matsubo Co., Ltd.). Is also preferably performed.
The obtained dispersion may contain coarse aggregated particles, which are preferably removed by a strainer or a filter. The preferable filtration accuracy at this time is 5 μm to 500 μm.

(Structure in film)
The state of rubber particles in the acrylic resin film according to the present invention is most preferably a state in which primary particles are uniformly and monodispersed. On the contrary, moderate aggregation or uneven distribution may occur within the range not deviating from the gist of the present invention.
For example, a mode in which the concentration of rubber particles is large near the surface layer of the film, or conversely, a mode in which the concentration is large near the center layer of the film can be selected according to the purpose.
The particle shape of each rubber particle can be arbitrarily selected such as a spherical shape, a flat shape, or a rod shape. A flat shape is preferable because the surface unevenness of the film is less affected, and it is preferable that the flat surface is parallel to the film surface.

(3) Cellulose Acylate In the acrylic resin film according to the present invention, by adding a very small amount of a cellulose acylate resin to the dope, the solubility of foreign matter due to the additive is increased, and the foreign matter failure reduction effect becomes remarkable. It is presumed that foreign substances resulting from the additives that are not soluble in the acrylic resin are compatible with the highly polar cellulose acylate resin, so that the foreign substances are significantly reduced.

Further, it is preferable to use a small amount of cellulose acylate in combination, from the viewpoint of improving the coating property when coating the functional layer on the surface of the film and reducing cissing and coating unevenness. Further, by containing the cellulose acylate resin, the adhesion to the hard coat substrate is increased, and the hardness of the hard coat film can be increased.

Particularly preferred 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. .. Specifically, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose propionate, cellulose butyrate, cellulose acetate propionate butyrate and the like can be mentioned, in the present invention, cellulose triacetate, cellulose Acetate propionate and cellulose acetate butyrate are preferred. The substitution degree of the acetyl group is preferably 1.40 or more. Cellulose as a raw material of cellulose acylate is not particularly limited, and cotton linter, wood pulp, kenaf and the like can be used. You may mix and use these. The ratio of cellulose acylate synthesized from 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 it can be synthesized, for example, by the method described in JP-A-10-45804. The acyl group substitution degree can be measured by ASTM-D817-96. The number average molecular weight of cellulose acylate is preferably in the range of 70,000 to 300,000, and more preferably in the range of 80,000 to 200,000 in order to obtain a mechanical strength preferable 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 thickeners described in JP-A-2005-314636 are used from the viewpoint of improving the castability and improving the occurrence of horizontal streaks and unevenness. , Is preferably added.

The casting method using an organic solvent as in the present invention is very advantageous from the viewpoint of productivity, but on the other hand, it is not easy to keep the solvent drying constant immediately after casting, and uneven surface is likely to occur. The term "planar unevenness" as used herein means streaks caused by poor leveling after casting, uneven drying caused by a difference in solvent drying rate, and uneven thickness caused by dry air.

As a 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 in order 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 unevenness during drying and streaking during casting, a method of adding thixotropy to the dope by adding an additive having a thixotropy (hereinafter, thixotropic agent) 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 having 4 or more carbon atoms and substituted with at least 8 fluorine atoms, Z represents a (t+s)-valent linking group, and B represents a substituted or unsubstituted alkyl group or aryl group. Or represents a heterocyclic group. t is an integer of 1 to 6, and s is an integer of 1 to 6.

In the formula, R represents an alkyl group having 4 or more carbon atoms and substituted with at least 8 fluorine atoms, R may be substituted with at least 8 fluorine atoms, and may be linear, branched or cyclic. Any structure of Further, it may be further substituted with a substituent other than a fluorine atom, or may be substituted only with a 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 (t+s)-valent linking group 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, but preferably t is an integer from 2 to 4, more preferably t is 2 or 3 and most preferably Preferably t is 2. In addition, s is preferably an integer of 1 to 4, and more preferably s is an integer of 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. An optically active substance is preferably used.

B represents a substituted or unsubstituted alkyl group, aryl group, or heterocyclic group.

<<Condition (a)>>
At any shear rate within the range of 0.01 to 5000 s ⁻¹ , a solution 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 There is 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 toluene, hexane, isopropanol, ethanol, methanol, chloroform, methyl ethyl ketone, 2-methylpentanone, and cyclohexanone are preferable. More preferred are toluene, methyl ethyl ketone, 2-methylpentanone and cyclohexanone, and most preferred are methyl ethyl ketone, 2-methylpentanone and cyclohexanone.

[2] An organic solvent-based thixotropy-imparting agent composed of the compound represented by the general formula (1b), which satisfies the following condition (b), is preferable.

<<Condition (b)>>
In a liquid containing the compound represented by the general formula (1b) at a concentration of 5% by mass or less, the viscosity η ( _x1 ) at any shear rate _x1 within the range of 0.01 to 5000 s ⁻¹ , _X2 / _x1 ≧10, the value η( _x1 )/η( _x2 ) for 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 item [1] or [2], wherein the compound represented by the general formula (1b) is represented by the following general formula (2b). Is preferred.

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 a substituent, T ₁ , T ₂ and L ₁ each independently represent a divalent linking group or a single bond, and k is 0 or 1. .. B represents a substituted or unsubstituted alkyl group, aryl group, or heterocyclic group.

[4] The organic solvent-based thickening agent 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 thixotropic agent.

In the formula, R ₁ and R ₂ each independently represent an alkyl group having 4 or more carbon atoms and substituted with at least 8 fluorine atoms. B represents a substituted or unsubstituted alkyl group, aryl group, or heterocyclic group. T ₃ and T ₄ each independently represent —O—, —S— or —NR ₂₃ —. 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 agent 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 thixotropic agent.

In the formula, A ₁ and A ₂ each independently represent a fluorine atom or a hydrogen atom. 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 each independently represent —O—, —S— or —NR ₂₃ —. 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, aryl group, or 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 [0089] of JP-A-2005-314636. The content of the above-mentioned fluorine-containing compound is not particularly limited, but is usually 0.01 to 10% by mass (% by mass based on the total mass of the dope) in the dope, preferably 0.01 to 5% by mass, and more preferably 0. 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 kind or in plural kinds.

(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 to the film, and in order to improve the slipperiness of the film surface, unevenness is imparted to the film surface. It is effective to add fine particles of an organic or inorganic substance to increase the roughness of the film surface and form a so-called matte, which is used to reduce the adhesiveness.

However, the rougher the surface, the more haze occurs and the transparency decreases, 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 of 1 to 1000 nm, preferably 1 to 100 nm, and more preferably 3 to 50 nm.

When the fine particles of the matting agent are used by adding them to various films, the content thereof in the film is 0.03 to 1% by mass with respect to 100% by mass of the film, regardless of whether the particles are spherical or amorphous particles. %, 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 preferable haze range of the acrylic resin film containing the matting agent in the present invention is 2.0% or less, 1.2% or less is more preferable, and 0.5% or less is particularly preferable. The preferred static friction coefficient of the acrylic resin film containing the matting agent is 1.5 or less, and 1.0 or less is particularly preferred. When the coefficient of static friction is 1.5 or less, the acrylic resin film does not cause cracks or winding wrinkles during winding during film formation and processing, and therefore the winding shape is impaired by the cracks or winding wrinkles, or cracks or wrinkles do not occur. No uniform tension is applied to the acrylic resin film, and there is no problem that unintended nonuniform optical properties are developed on the film surface.

Statistic friction coefficient is measured between the same materials, and is specifically measured according to the method described in the 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 can 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. Titanium dioxide (rutile type or anatase type) produced by silicon dioxide or titanium slag and sulfuric acid can be used. It can also be obtained by crushing from an inorganic material having a relatively large particle size, for example, 20 μm or more, and then classifying (vibrating filtration, air classification, etc.). It is preferable that the inorganic fine particles contain silicon because the turbidity is low and the haze of the film can be reduced. 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 the surface treatment include halosilanes, alkoxysilanes, silazanes, siloxanes and the like.

Further, as the polymer compound, there are polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, starch and the like, and pulverized and classified products thereof are also included. Alternatively, a polymer compound synthesized by a suspension polymerization method, a polymer compound spherically formed by a spray drying method or a dispersion method, or an inorganic compound can be used.

Also, a polymer compound which is a polymer of one or more of the following monomer compounds may be formed 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 diester. Ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, 2-chloroethyl, cyanoethyl, 2-acetoxyethyl, dimethylaminoethyl, benzyl, cyclohexyl, furfuryl, phenyl, 2-hydroxyethyl, 2-ethoxyethyl, glycidyl, ω -Methoxy polyethylene glycol (the number of moles added is 9) and the like.

Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate, vinyl methoxyacetate, 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 and 2,3-dimethylbutadiene.

Examples of styrenes include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, trifluoromethylstyrene, vinyl. Examples thereof include benzoic acid methyl ester.

Examples of acrylamides include acrylamide, methyl acrylamide, ethyl acrylamide, propyl acrylamide, butyl acrylamide, tert-butyl acrylamide, phenyl acrylamide and dimethyl acrylamide; methacrylamides such as methacrylamide, methyl methacrylamide, ethyl methacrylamide, propyl methacryl Amides, tert-butyl methacrylamide, 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 methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone and the like; vinyl heterocyclic compounds such as vinyl pyridine, N-vinyl imidazole, N-vinyl oxazolidone, N-vinyl triazole, N-vinylpyrrolidone and the like; unsaturated nitriles such as acrylonitrile, methacrylonitrile and the like; polyfunctional monomers such as divinylbenzene, methylenebisacrylamide, ethylene glycol dimethacrylate and the like.

Further, acrylic acid, methacrylic acid, itaconic acid, maleic acid, monoalkyl itaconate (eg, monoethyl itaconate); monoalkyl maleate (eg, monomethyl maleate; styrene sulfonic acid, vinyl benzyl sulfonic acid, vinyl) Sulfonic acid, acryloyloxyalkylsulfonic acid (eg, acryloyloxymethylsulfonic acid); methacryloyloxyalkylsulfonic acid (eg, methacryloyloxyethylsulfonic acid); acrylamidoalkylsulfonic acid (eg, 2-acrylamido-2-methylethane) Methacrylic acid alkyl sulfonic acid (eg, 2-methacrylamido-2-methylethane sulfonic acid); acryloyloxyalkyl phosphate (eg, acryloyloxyethyl phosphate), etc. These acids are alkali. It may be a salt of a metal (for example, Na, K, etc.) or an ammonium ion, and as other monomer compounds, U.S. Patent Nos. 3,459,790, 3,438,708, 3,554,987, and 4,215,195 may be used. No. 4,247,673 and JP-A No. 57-205735, etc. can be used, which is preferable, and specific examples of such a cross-linkable monomer include N-(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, particles having a fluorine atom or a silicone atom as described in JP-A Nos. 62-14647, 62-17744, and 62-17743 may be used in the present invention.
The matting agent particles of these polymers or copolymers preferably have a glass transition temperature higher than 25°C.

Among these, the particle composition preferably used is polystyrene, polymethyl(meth)acrylate, polyethyl acrylate, poly(methyl methacrylate/methacrylic acid=95/5 (molar ratio), poly(styrene/styrene sulfonic acid=95/5( (Molar ratio), polyacrylonitrile, poly(methyl methacrylate/ethyl acrylate/methacrylic acid=50/40/10), silica and the like.

Further, as the matting agent used in the present invention, particles having a reactive (particularly gelatin) group described in JP-A No. 64-77052 and European Patent No. 307855 can be used. Further, a large amount of groups that can be dissolved in alkaline or acid can be contained. The matting agent contains an inorganic compound or a polymer compound, and its average primary particle size 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 of the matting agent is not particularly limited as long as the fine particles of the matting agent are dispersed and the dispersion can be prepared. The organic solvent used in the present invention is, for example, a chlorine-based solvent such as dichloromethane or chloroform, a solvent selected from chain hydrocarbons having 3 to 12 carbon atoms, cyclic hydrocarbons, aromatic hydrocarbons, esters, ketones and ethers. Is preferred. The ester, ketone and ether may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, decane and the like. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane, decalin and derivatives thereof. Examples of the aromatic hydrocarbon having 3 to 12 carbon atoms include benzene, toluene and xylene. Examples of the ester 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 phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. As the organic solvent used in the method for preparing a matting agent particle dispersion 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 at an arbitrary ratio. ..

When the fine particles of the matting agent are dispersed, if the amount of the above organic solvent is small, the particles cannot be sufficiently dispersed, and aggregates are generated, which causes foreign matter failure. 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 from the viewpoint of handling in production. Therefore, the amount of the organic solvent used is preferably in the range of 1,000 to 100,000 parts by mass, more preferably in the range of 1,500 to 40,000 parts by mass, and further preferably in the range of 2,000 to 20,000, based on 100 parts by mass of the fine particles of the matting agent. The range of parts by mass is particularly preferable.

(Dispersant)
Next, the dispersant used in the present invention will be described. When the fine particle dispersion liquid of the matting agent and the dope are mixed in-line, if the dispersion liquid having a low viscosity is used, it is difficult to add to the dope having a high viscosity due to the difference in viscosity and it is difficult to add the mixture. 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 mixing, it is preferable that the viscosity of the dope and the dispersion liquid are the same, but in consideration of the dispersibility of the matting agent as a fine particle dispersion and the ease of handling, the viscosity of the matting agent fine particle dispersion is 0.7 mPa ·S or more is preferable, and 1 mPa·s or more is more preferable. Further, if the weight average molecular weight of the dispersant is too large in order to increase the viscosity, poor solubility of the dispersant and deterioration of filterability are caused. Therefore, in order to prepare a dispersion having excellent solubility and filterability that does not lose power against the dope, the weight average molecular weight of the dispersant is preferably in the range of 10,000 to 500,000, more preferably 10,000 to 300,000, and more preferably 30,000 to The range of 200,000 is more preferable.

It is preferable to use an acrylic resin as a dispersant and further disperse the fine particles in the presence of the dispersant. This is preferable from the viewpoint that the compatibility of the fine particle dispersion 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 having no agglomerates 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 the 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 the 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, it is possible to suppress fluctuations in phase difference due to humidity fluctuations in the environment and to reduce contrast. It is possible to suppress the deterioration and the occurrence of color unevenness. Further, it can also function as a phase difference increasing agent.

A 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 humidity fluctuation and the generation of scattered matter.

(Compound having structure represented by general formula (A1))

In the 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- Etc.), a cycloalkyl group (cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), an aromatic hydrocarbon ring or an aromatic heterocycle. Among these, an aromatic hydrocarbon ring or an aromatic heterocycle is preferable, and a 5-membered 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 examples thereof include a benzene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a 1,2,3-triazole ring, and a 1,2 ring. , 4-triazole ring, tetrazole ring, furan ring, oxazole ring, isoxazole ring, oxadiazole ring, isoxadiazole ring, thiophene ring, thiazole ring, isothiazole ring, thiadiazole ring, isothiadiazole 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 as the substituent, 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-cyclohexen-1-yl group, etc.) ), alkynyl groups (ethynyl group, propargyl group, etc.), aromatic hydrocarbon ring groups (phenyl group, p-tolyl group, naphthyl group, etc.), aromatic heterocyclic groups (2-pyrrole group, 2-furyl group, 2) -Thienyl group, pyrrole group, imidazolyl group, oxazolyl group, thiazolyl group, benzimidazolyl 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, isoxazole group, 1,2,4-oxadiazole group, 1,3,4-oxadiazole group, thiazole group, Isothiazole group, 1,2,4-thiodiazole group, 1,3,4-thiadiazole 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) 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 groups (methyl Sulfonylamino group, butylsulfonylamino group, 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) 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 carbamoyl group, N-methylcarbamoyl group, N,N-dimethylcarbamoyl group, N,N-di-n-octylcarbamoyl group, N-(methylsulfonyl)carbamoyl group and the like.

In the general formula (A1), A ₁ , A ₂ and B each 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 excellent in the effect of changing optical characteristics and excellent in durability can be obtained.

In the general formula (A1), it is preferable that T ₁ and T ₂ each independently represent a pyrrole ring, a pyrazole ring, an imidazole ring, a 1,2,3-triazole ring or a 1,2,4-triazole ring. .. Among these, a pyrazole ring, a triazole ring or an imidazole ring is particularly preferable because it is excellent in the effect of suppressing the fluctuation of the phase difference with respect to humidity fluctuation, and a resin composition having excellent durability can be obtained. It is particularly preferable that The pyrazole ring, 1,2,3-triazole ring, 1,2,4-triazole ring or imidazole ring represented by T ₁ and T ₂ may be tautomers. Specific structures of the pyrrole ring, the pyrazole ring, the imidazole ring, the 1,2,3-triazole ring and the 1,2,4-triazole ring are shown below.

In the formula, * represents a 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 substituent. Examples of the non-aromatic substituent represented by R ⁵ include the same groups as the non-aromatic substituents among the substituents that A ₁ in the general formula (A1) may have. 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 likely to be twisted, and A ₁ , B and T ₁ form an interaction with an acrylic resin. Since it becomes impossible, it is difficult to suppress the fluctuation of the optical characteristics. In order to enhance the effect of suppressing fluctuations in optical properties, R ⁵ is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an acyl group having 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 which A ₁ and A ₂ in the general formula (A1) may have. Similar groups may 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 a 5-membered or 6-membered group with 2 or less atoms interposed therebetween. Membered aromatic hydrocarbon rings or aromatic heterocycles are linked. Through 2 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 linking atoms is not particularly limited, but from an alkylene group, an alkenylene group, an alkynylene group, O, (C=O), NR, S, (O=S=O) It represents a divalent linking group selected from the group consisting of or a combination of two of them. 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.), 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) Group, 2-pyrimidinyl group, 2-benzothiazolyl group, 2-pyridyl group), cyano group and the like. 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, in the general formula (A1), A ₁ and A ₂ may be the same groups as the substituents which A ₂ may have.

In the general formula (A1), L ₁ , L ₂ , L ₃ and L ₄ are a resin that adsorbs water by increasing the planarity of the compound having the structure represented by the general formula (A1). Of the 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 0-5. 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 is, and the more excellent the effect of suppressing fluctuation of optical properties is. Excellent compatibility with resins that adsorb Therefore, n is preferably an integer of 1 to 3, more preferably an integer of 1 to 2.

<Compound having structure represented by general formula (A2)>
The compound having a structure represented by general formula (A1) is preferably a compound having a structure represented by general formula (A2).

(In the formula, A ₁ , A ₂ , T ₁ , T ₂ , L ₁ , L ₂ , L ₃ and L ₄ are respectively A ₁ , A ₂ , T ₁ , T ₂ and L in the general formula (A1). ₁ , L ₂ , L ₃ and L ₄ have the same meanings, A ₃ and T ₃ respectively represent the same groups as A ₁ and T ₁ in the general formula (A1), and L ₅ and L ₆ represent the above-mentioned general groups. It represents the same group as L ₁ in formula (A1), and m represents an integer of 0 to 4.)
Since the smaller m is, the better the compatibility with the cellulose acylate is, m is preferably an integer of 0 to 2, and more preferably an integer of 0 to 1.

<Compound having structure represented by general formula (A1.1)>
The compound having a structure represented by general formula (A1) is preferably a triazole compound having a 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 1-4 . T ₁ represents a 1,2,4-triazole ring.)
Furthermore, the triazole compound having a structure represented by the general formula (A1.1) is preferably a triazole compound having a 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 at least one Z substituted on the benzene ring. Attaches to the ortho or 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 bonding position with the benzene ring. T ₁ represents a 1,2,4-triazole ring. Represents.)
The compound having a 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 include an organic solvent, and the solvate may include water. That is, the "hydrate" and "solvate" include a mixed solvate containing both water and an organic solvent. Salts include acid addition salts formed with inorganic or organic acids. Examples of inorganic acids include, but are not limited to, hydrohalic acids (such as hydrochloric acid, hydrobromic acid), 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, alkylsulfonic acid (methanesulfonic acid, etc.), allylsulfonic acid (benzenesulfonic acid, 4-toluene). Sulfonic acid, 1,5-naphthalenedisulfonic acid, etc.) and the like, but are not limited thereto. Of these, preferred are hydrochlorides, acetates, propionates and butyrates.

Examples of salts include acidic moieties present on the parent compound which are metal ions (eg alkali metal salts, eg sodium or potassium salts, alkaline earth metal salts, eg calcium or magnesium salts, ammonium salts alkali metal ions, alkaline earth salts). Metal ions, or aluminum ions, etc.), or salts formed when adjusted with organic bases (ethanolamine, diethanolamine, triethanolamine, morpholine, piperidine, etc.), and also these Not limited. Of these, sodium salts and potassium salts are preferable.

Examples of the solvent included in the solvate include any of common organic solvents. Specifically, alcohol (eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol), ester (eg, ethyl acetate), hydrocarbon (eg, toluene, hexane) , Heptane), ether (eg, tetrahydrofuran), nitrile (eg, acetonitrile), ketone (acetone) and the like. Preferred are solvates of alcohols (eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol). These solvents may be a reaction solvent used in the synthesis of the compound, a solvent used in the crystallization purification after the synthesis, or a mixture thereof.

Further, it may contain two or more kinds of solvents at the same time, or may contain water and a solvent (eg, water and alcohol (eg, methanol, ethanol, t-butanol, etc.)).

Even if the compound having a structure represented by the general formula (A1), (A2), (A1.1) or (A1.2) is added in a form containing no water, solvent or salt, A hydrate, solvate or salt may be formed in the resin composition or acrylic resin film of the 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 compound, the better the compatibility with the resin and the larger the molecular weight. Since the effect of suppressing fluctuations in optical value with respect to changes in environmental humidity is higher, it is 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).

(In the formula, A represents a pyrazole ring, Ar ₁ and Ar ₂ each represent an aromatic hydrocarbon ring or an aromatic heterocycle, and may have a substituent. R ₁ represents 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 is the 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle mentioned in the general formula (A1), respectively. preferable. In addition, examples of the substituent of Ar ₁ and Ar ₂ include the same substituents as those shown for the compound having the structure represented by the general formula (A1).

Specific examples of R ₁ include 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). 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), An aryloxy carbonyl group (for example, a phenoxy carbonyl group etc.) etc. are mentioned.

Q represents an integer of 1 to 2, and n and m represent an integer of 1 to 3.

Specific examples of the compound having a 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocycle used in the present invention are shown below. Among them, it is a compound having a structure represented by the general formula (A1), (A2), (A1.1), or (A1.2), or a compound having a structure represented by the general formula (A3). preferable. The compound having a 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. In addition, as mentioned above, the following specific examples may be tautomers and 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. In the compound 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 iminoether derivative and a hydrazide derivative may be used. A 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 may be an ester type (eg, ethyl acetate, methyl acetate, etc.), an amide type (dimethylformamide, dimethylacetamide, etc.), an ether type. (Ethylene glycol dimethyl ether etc.), Alcohol type (eg methanol, ethanol, propanol, isopropanol, n-butanol, 2-butanol, ethylene glycol, ethylene glycol monomethyl ether etc.), aromatic hydrocarbon type (eg toluene, xylene etc.) ), water can be mentioned. The solvent used is preferably an alcohol solvent. Moreover, these solvents may be mixed and used.

The amount of the solvent used is not particularly limited, but it is preferably within a range of 0.5 to 30 times, and more preferably 1.0 to 25 times the amount of the hydrazide derivative used. Yes, and particularly preferably in the range of 3.0 to 20 times.

When a nitrile derivative and a hydrazide derivative are reacted, it is not necessary to use a catalyst, but it is preferable to use a catalyst to accelerate the reaction. The catalyst used may be an acid or a base. 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 by diluting it with water, or by adding a gas into the system. As the base, an inorganic base (potassium carbonate, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, potassium hydroxide, sodium hydroxide, etc.) and an organic base (sodium methylate, sodium ethylate, potassium methylate, potassium ethylate, Sodium butyrate, potassium butyrate, diisopropylethylamine, N,N′-dimethylaminopyridine, 1,4-diazabicyclo[2.2.2]octane, N-methylmorpholine, imidazole, N-methylimidazole, pyridine, etc.) Either may be used, potassium carbonate is preferable as the inorganic base, and sodium ethylate, sodium ethylate, and sodium butyrate are preferable as the organic base. The inorganic base may be added as a powder, or may be added in a state of being dispersed in a solvent. In addition, 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 it is preferably in the range of 1.0 to 5.0 times by mole with respect to the triazole ring formed, and further 1.05 to 3. The molar ratio is preferably 0 times.

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.

There are no particular restrictions on the method of adding the raw materials, solvent and catalyst used in the reaction, and the catalyst may be added last or the solvent may be added last. A method in which the nitrile derivative is dispersed or dissolved in a solvent, the catalyst is added, and then the hydrazide derivative is added is also preferable.

The temperature of the solution during the reaction may be any temperature as long as the reaction proceeds, but it is preferably in the range of 0 to 150°C, more preferably in the range of 20 to 140°C. Further, the reaction may be carried out while removing the produced water.

Any method 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 it 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 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 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 extracting with an appropriate organic solvent, it is preferable to wash the organic solvent with water after the extraction and then concentrate. The suitable organic solvent referred to herein is a water-insoluble solvent such as ethyl acetate, toluene, dichloromethane, or ether, or a mixed solvent of the water-insoluble solvent and tetrahydrofuran or an alcohol solvent, preferably It is ethyl acetate.

When the compound having the structure represented by the general formula (A1) is crystallized, there is no particular limitation, but a method in which water is added to the neutralized reaction solution for crystallization, or a compound represented by the general formula (A1) is used. A method of neutralizing an aqueous solution in which a compound having the structure described above is dissolved to perform crystallization 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. did. The reaction solution 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 precipitate collected by filtration 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 then 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 H-NMR (400 MHz, solvent: heavy DMSO, standard: tetramethylsilane) δ (ppm): 7.56 to 7.48 (6 H, m), 7.62 to 7.61 (4 H, m)
(Synthesis of Exemplified Compound 6)
Exemplified compound 6 can be synthesized by the following scheme.

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 to 40 ml of n-butanol, and the mixture was heated at 120° C. under a nitrogen atmosphere. It 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, then the precipitated solid was separated by filtration and washed with pure water. Water and ethyl acetate were added to the obtained solid for liquid separation, and the organic layer was washed with pure water. The organic layer was dried over magnesium sulfate, and the solvent was evaporated 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 H-NMR (400 MHz, solvent: heavy DMSO, reference: tetramethylsilane) δ (ppm): 8.83 (1 H, s), 8.16 to 8.11 (6 H, m), 7.67 to 7 .54 (7H, m)
(Synthesis of Exemplified Compound 176)
The 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 little by little while stirring under ice cooling with ice water under a nitrogen atmosphere. .. After stirring for 3 hours under ice-water cooling, the mixture was stirred for 12 hours under water cooling. After concentrated sulfuric acid was added to the reaction solution for neutralization, pure water and ethyl acetate were added for liquid separation, and the organic layer was washed with pure water. The organic layer was dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. 55.2 g of Intermediate A was obtained by adding methanol to the obtained crude crystals and performing suspension washing.

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 little by little while stirring at room temperature. 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 for liquid separation, and the organic layer was washed with pure water. The organic layer was dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The crude crystals obtained 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 Exemplified Compound 176 is as follows. The measurement was carried out by adding a few drops of trifluoroacetic acid to the measurement solvent in order to prevent the chemical shift from becoming complicated due to the presence of the tautomer.

¹ H-NMR (400 MHz, solvent: heavy DMSO, reference: tetramethylsilane) δ (ppm): 8.34 (1 H, s), 7.87 to 7.81 (6 H, m), 7.55 to 7 0.51 (1H, m), 7.48 to 7.44 (4H, m), 7.36 to 7.33 (2H, m), 7.29 (1H, s)
Other compounds can be synthesized by the same method.

<Using Method of Compound Having Structure Represented by General Formula (A1)>
The compound having a 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. The content is preferably 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 of 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), it may be added in the form of powder to the resin forming the acrylic resin film, and after dissolving in a solvent, the acrylic resin film is formed. It may be added to the resin.

(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 reduction 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 the organic ester is preferably at least one selected from sugar ester, polycondensation ester, and polyhydric alcohol ester, and the polycondensation ester is An ester having no nitrogen atom in its structure is preferable.

(Measurement of melting point of organic ester)
The melting point was measured using an EXSTAR 6220TG/DTA, a differential thermal and thermogravimetric simultaneous measuring device manufactured by Seiko Instruments. 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 must have a melting point within the range of −60 to 120° C., preferably within the range of −45 to 90° C., in order to exhibit the effects of the present invention.

When the melting point of the organic ester is within the range of −60 to 120° C., the organic ester scatters in the production line and is easily liquefied after being cooled. ..

(Measurement of 1% mass reduction temperature of organic ester)
The 1% mass reduction temperature Td1 of the organic ester is measured, for example, by a differential thermal/thermogravimetric simultaneous measurement device manufactured by Seiko Instruments, EXSTAR6200TG/DTA, 10 mg of the sample compound is put in an aluminum pan, and 100°C at 50°C/min. After heating to 40° C. for 40 minutes, the temperature is raised to 400° C. at 10° C./min, and the mass variation is monitored. To 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 effects of the present invention. ..

When the 1% mass reduction temperature of the organic ester is 100° C. or higher, the viscosity when liquefied after scattering and cooling is appropriate, and the bulkiness of the scattered nitrogen-containing heterocyclic compound can be reduced. When the% mass reduction temperature is 350° C. or lower, the amount of the nitrogen-containing heterocyclic compound necessary for reducing the bulkiness of the scattered material is scattered, and a sufficient effect can be obtained.

Hereinafter, sugar esters, polycondensation esters, and polyhydric alcohol esters will be described as the 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 As the sugar ester used in the present invention, a sugar ester having 1 or more and 12 or less of at least one pyranose ring or furanose ring and esterifying all or part of the OH groups of the structure. It is preferably an ester.

The sugar ester used in the present invention is a compound containing at least either a furanose ring or 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 OH group of the sugar structure is esterified. In the sugar ester according to the present invention, the average ester substitution degree is preferably in the range of 4.0 to 8.0, 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 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 is a direct bond to the residue of a monosaccharide or a disaccharide. Is the total number of hydroxy groups present, and n is the total number of —(OC(═O)—R ² ) groups directly bonded to the residues of the monosaccharide or disaccharide, 3≦m+n≦8, and n≠0.

The sugar ester having the structure represented by the general formula (B) is a single type of ester in which the number of hydroxy groups (m) and the number of -(OC(=O)-R ² ) groups (n) are fixed. It is difficult to isolate as a compound, and it is known that a compound is obtained by mixing several kinds of components having different m and n in the formula. Therefore, 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 of the present invention has In this case, a sugar ester having an average degree of ester substitution within the range of 5.0 to 7.5 is preferable.

In the above general formula (B), G represents a monosaccharide or disaccharide residue. Specific examples of monosaccharides include allose, altrose, glucose, mannose, gulose, idose, galactose, talose, ribose, arabinose, xylose and lyxose.

Specific examples of the compound having a monosaccharide residue of the sugar ester represented by the general formula (B) are shown below, but the present invention is not limited to these exemplified compounds.

Further, specific examples of the disaccharide residue include trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, isotrehalose and the like.

Specific examples of the compound having a disaccharide residue of the sugar ester represented by the general formula (B) are shown below, 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 independently have a substituent.

Further, in the general formula (B), m is the total number of hydroxy groups directly bonded to the residues of the monosaccharide or disaccharide, and n is directly bonded to the residues of the monosaccharide or disaccharide. Is the total number of —(O—C(═O)—R ² ) groups. Then, it is necessary that 3≦m+n≦8, and preferably 4≦m+n≦8. Also, n≠0. When n is 2 or more, the -(OC(=O)-R ² ) groups may be the same or different from each other.

The aliphatic group in the definition of R ² may be linear, branched or cyclic and preferably has 1 to 25 carbon atoms, more preferably 1 to 20 carbon atoms, or 2 Those of -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 and didecyl groups.

The aromatic group in the definition of R ² may be an aromatic hydrocarbon group or an aromatic heterocyclic group, more preferably an aromatic hydrocarbon group. The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 12 carbon atoms. Specific examples of the aromatic hydrocarbon group include rings such as benzene, naphthalene, anthracene, biphenyl, and terphenyl. As the aromatic hydrocarbon group, a benzene ring, a naphthalene ring and a biphenyl ring are particularly preferable. The aromatic heterocyclic group is preferably a ring containing at least one of an oxygen atom, a nitrogen atom and a sulfur atom. Specific examples of the heterocycle include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, Examples thereof include isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. 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. The melting point and the 1% mass reduction temperature Td1 of all of the following exemplified compounds are within the scope of the present invention.

The sugar ester may contain two or more different substituents in one molecule, contains an aromatic substituent and an aliphatic substituent in one molecule, and contains two or more different aromatic substituents. Two or more different aliphatic substituents contained in one molecule can be contained in one molecule.

Also, it is preferable to contain a mixture of two or more types of sugar ester. 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 General Formula (B)>
The following is an example of the synthesis of sugar ester that can be preferably used in the present invention.

34.2 g (0.1 mol) of sucrose, 180.8 g (0.8 mol) of benzoic anhydride, and pyridine were placed in a four-head Kolben equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas inlet tube. 379.7 g (4.8 mol) of each was charged, and the temperature was raised while bubbling nitrogen gas through the nitrogen gas introduction tube under stirring, and the esterification reaction was carried out at 70° C. for 5 hours. Next, after decompressing the inside of Kolben to 4×10 ² Pa or less and distilling off excess pyridine at 60° C., depressurizing the inside of Kolben to 1.3×10 Pa or less and raising the temperature to 120° C., anhydrous benzoin Most of the acid and benzoic acid formed were distilled off. Then, 1 L of toluene and 300 g of a 0.5% by mass sodium carbonate aqueous solution were added, and the mixture was stirred at 50° C. for 30 minutes and then left standing 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, the toluene layer was separated, and the toluene was distilled off at 60° C. under reduced pressure (4×10 ² Pa or less). A mixture of compounds A-1, A-2, A-3, A-4 and A-5 was obtained. The obtained mixture was analyzed by HPLC and LC-MASS. As a result, A-1 was 7% by mass, A-2 was 58% by mass, A-3 was 23% by mass, A-4 was 9% by mass, 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 100% pure A-1, A-2, A-3, A-4 and A-5.

The addition amount of the sugar ester is preferably in the range of 0.1 to 20% by mass, more preferably in the range of 1 to 15% by mass, based on the acrylic resin.

(7-2) Polycondensed Ester In the acrylic resin film according to the present invention, it is preferable to use a polycondensed ester having a structure represented by the following general formula (C) as the organic ester because of its dimensional stability against changes in temperature and humidity. From the viewpoint of.

Due to its plasticizing effect, the polycondensed ester is preferably contained in the range of 1 to 30% by mass, more preferably 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 general formula (C), B ₃ and B ₄ each independently represent an aliphatic or aromatic monocarboxylic acid residue or a hydroxy group. 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 alkylenedicarboxylic acid residue having 4 to 12 carbon atoms or an aryldicarboxylic 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 and a diol, A represents a carboxylic acid residue in the polycondensation ester, and G ₂ represents an alcohol residue. Represent

The dicarboxylic acid forming the polycondensed ester is an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid, and preferably an aromatic dicarboxylic acid. The dicarboxylic acid may be one type or a mixture of two or more types. In particular, it is preferable to mix aromatic and aliphatic.

The diol constituting the polycondensed ester is an aromatic diol, an aliphatic diol or an alicyclic diol, preferably an aliphatic diol, 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 include a repeating unit obtained by reacting a dicarboxylic acid containing at least 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. More preferably, it contains a repeating unit obtained by reacting with a diol having 1 to 8 carbon atoms.

Both ends of the polycondensed ester molecule may or may not be sealed.

Specific examples of the alkylenedicarboxylic acid that constitutes A in the general formula (C) include 1,2-ethanedicarboxylic acid (succinic acid), 1,3-propanedicarboxylic acid (glutaric acid), and 1,4-butanedicarboxylic acid. It includes a divalent group derived from (adipic acid), 1,5-pentanedicarboxylic acid (pimelic acid), 1,8-octanedicarboxylic acid (sebacic acid) and the like. Specific examples of the alkenylene dicarboxylic acid that constitutes A include maleic acid and fumaric acid. Specific examples of the aryldicarboxylic acid that constitutes A include 1,2-benzenedicarboxylic acid (phthalic acid), 1,3-benzenedicarboxylic acid, 1,4-benzenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid. 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 alkylenedicarboxylic 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. It represents a divalent group derived from oxyalkylene glycol of the formula 4 to 12.

Examples of the divalent group derived from alkylene glycol 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-butanediol, 1,2-propanediol, 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- Included are 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 the aryl glycol having 6 to 12 carbon atoms in G ₂ include 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol) and 1,4-dihydroxy. A divalent group derived from benzene (hydroquinone) or the like is included. Examples of the divalent group derived from oxyalkylene glycol having 4 to 12 carbon atoms in G are derived from diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and the like. Divalent groups are included.

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 each a monovalent group derived from an aromatic ring-containing monocarboxylic acid or an aliphatic monocarboxylic acid, or a hydroxy group.

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 not only the aromatic ring directly bonded to a carboxy group, Also included are 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, paratertiarybutylbenzoic acid, orthotoluic acid, metatoluic acid, paratoluic acid, dimethylbenzoic acid, ethylbenzoic acid, normal propylbenzoic acid. , Monobenzoic acid, acetoxybenzoic acid, phenylacetic acid, 3-phenylpropionic acid and the like. Among them, benzoic acid and paratoluic acid are preferable.

Examples of monovalent groups derived from aliphatic monocarboxylic acids include monovalent groups derived from acetic acid, propionic acid, butanoic acid, caprylic acid, caproic acid, decanoic acid, dodecanoic acid, stearic acid, oleic acid, etc. Groups are included. Among them, a monovalent group derived from an alkyl monocarboxylic acid having an alkyl moiety having 1 to 3 carbon atoms is preferable, and an acetyl group (a monovalent group derived from acetic acid) is more preferable.

The weight average molecular weight of the polycondensed ester used in the present invention is preferably in the range of 500 to 3000, 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 polycondensed ester having the structure represented by the general formula (C) will be shown, but the polycondensed ester is not limited thereto. The melting point and the 1% mass reduction temperature Td1 of all of the following exemplified compounds are within the scope of the present invention.

The following describes specific synthesis examples of the polycondensed ester described above.

<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 rapid cooling tube. Gradually raise the temperature with stirring until it reaches 230° C. in a nitrogen stream. A dehydration condensation reaction was performed 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 polycondensed 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, 2 L four-neck equipped with a thermometer, a stirrer, and a rapid cooling tube. The mixture is placed in a flask and gradually heated in a nitrogen stream until the temperature reaches 230° C. with stirring. A dehydration condensation reaction was performed 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 polycondensed 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, 2 L four-neck equipped with a thermometer, a stirrer, and a rapid cooling tube. The mixture is placed in a flask and gradually heated in a nitrogen stream until the temperature reaches 230° C. with stirring. A dehydration condensation reaction was performed 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 polycondensed ester P3. The acid value was 0.50 and the number average molecular weight was 2000.

<Polycondensation ester P4>
1,2-Propylene glycol (251 g), terephthalic acid (354 g), benzoic acid (610 g), and tetraisopropyl titanate (0.191 g) as an esterification catalyst were charged into a 2 L four-necked flask equipped with a thermometer, a stirrer, and a rapid cooling tube, and nitrogen was charged. Gradually raise the temperature with stirring until the temperature reaches 230° C. in an air stream. A dehydration condensation reaction was performed while observing the degree of polymerization. After the reaction was completed, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200° C. to obtain polycondensed 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-troylic 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 rapid cooling tube. The temperature is gradually raised with stirring in a nitrogen stream until the temperature reaches 230°C. A dehydration condensation reaction was performed 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 polycondensed 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 adipic 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 rapid cooling tube, and the mixture was placed in a nitrogen stream. Gradually raise the temperature with stirring until the temperature reaches 200°C. A dehydration condensation reaction was performed 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 polycondensed ester P6. The acid value was 0.10 and the number average molecular weight was 400.

<Polycondensation ester P7>
Charge 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 into a 2 L four-necked flask equipped with a thermometer, a stirrer, and a rapid cooling tube. The temperature is gradually raised with stirring in a nitrogen stream until the temperature reaches 200°C. A dehydration condensation reaction was performed 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 polycondensed 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 charged into a 2 L four-necked flask equipped with a thermometer, a stirrer, and a rapid cooling tube, and nitrogen was added. Gradually raise the temperature in an air stream with stirring until the temperature reaches 200°C. A dehydration condensation reaction was performed 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 polycondensed ester P8. The acid value was 0.50 and the number average molecular weight was 1200.

<Polycondensation ester P9>
The reaction conditions were changed by the same production method as for the polycondensed ester P2 to obtain a polycondensed 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 also contains a polyhydric alcohol ester.

The polyhydric alcohol ester is a compound composed of an ester of an aliphatic polyhydric alcohol having a valence of 2 or more and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. It is preferably an aliphatic polyhydric alcohol ester having a valence of 2 to 20.

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 the OH group represents an alcoholic and/or phenolic hydroxy group.

Examples of preferable polyhydric alcohols include the followings, 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 include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol and the like.

Especially, 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, etc. 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.

The following may be mentioned as examples of preferable monocarboxylic acids, but the present invention is not limited thereto.

As the aliphatic monocarboxylic acid, a straight-chain or side-chain fatty acid having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1 to 20, particularly preferably 1 to 10. It is preferable to contain acetic acid because the compatibility with cellulose acetate increases, and it is also preferable to use acetic acid and another monocarboxylic acid as a mixture.

Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecyl acid, Saturated fatty acids such as myristic acid, pentadecyl acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, heptacosanoic acid, montanic acid, melissic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acids, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

Examples of preferable alicyclic monocarboxylic acid include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

Examples of preferred aromatic monocarboxylic acids include benzoic acid, toluic acid and other benzoic acids having 1 to 3 alkoxy groups such as alkyl groups, methoxy groups or ethoxy groups introduced into the benzene ring, biphenylcarboxylic acid, Examples thereof include aromatic monocarboxylic acids having two or more benzene rings such as naphthalenecarboxylic acid and tetralincarboxylic acid, or derivatives thereof. Benzoic acid is particularly preferable.

The molecular weight of the polyhydric alcohol ester is not particularly limited, but it is preferably in the range of 300 to 1500, more preferably in the range of 350 to 750. A higher molecular weight is preferable because it is less likely to volatilize, and a lower molecular weight is preferable in terms of moisture permeability and compatibility with cellulose acylate.

The carboxylic acid used for 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 a part thereof may be left as it is.

The following are specific examples of polyhydric alcohol ester compounds. The melting point and the 1% mass reduction temperature Td1 of all of the following exemplified compounds are within the scope of the present invention.

The polyhydric alcohol ester used in the present invention is contained in the acrylic resin film in an amount of preferably 0.5 to 5% by mass, more preferably 1 to 3% by mass, and further preferably 1 to 3% by mass. It is particularly preferable that the content is 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 The acrylic resin film according to the present invention may use a phosphoric acid ester. Examples of the phosphoric acid ester include triaryl phosphoric acid ester, diaryl phosphoric acid ester, monoaryl phosphoric acid ester, arylphosphonic acid compound, arylphosphine oxide compound, condensed aryl phosphoric acid ester, halogenated alkyl phosphoric acid ester, halogen-containing condensed phosphoric acid. Examples thereof include esters, halogen-containing condensed phosphonates, halogen-containing phosphites and the like.

Specific phosphoric acid esters include triphenyl phosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phenylphosphonic acid, tris(β-chloroethyl)phosphate, tris(dichloro). Propyl)phosphate, tris(tribromoneopentyl)phosphate and the like can be mentioned.

(8-2) Glycolic Acid Esters In the present invention, glycolic acid esters (glycolate compounds) can be used as one type of polyhydric alcohol ester.

The glycolate compound applicable to the present invention is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used.

Examples of the alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl. Ethyl glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl Glycolate, butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalyl ethyl glycolate, etc. are mentioned, and preferably ethyl phthalyl ethyl glycolate. 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 is intended to improve light resistance by absorbing ultraviolet rays having a wavelength 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 To 20%, more preferably 5 to 10%.

The ultraviolet absorber preferably used in the present invention is a benzotriazole type ultraviolet absorber which is a nitrogen-containing heterocyclic compound, a benzophenone type ultraviolet absorber, a triazine type ultraviolet absorber, particularly preferably a benzotriazole type ultraviolet absorber and benzophenone. It is a UV absorber.

For example, 5-chloro-2-(3,5-di-sec-butyl-2-hydroxyphenyl)-2H-benzotriazole, (2-2H-benzotriazol-2-yl)-6-(straight chain and pendant Chain dodecyl)-4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., and also tinuvin 109, tinuvin 171, tinuvin 234, tinuvin 326, tinuvin 327, tinuvin 328, There are tinuvins such as tinuvin 928, all of which are commercial products manufactured by BASF Japan Ltd., and can be preferably used. Of these, halogen-free ones are preferable.

In addition, discotic compounds such as compounds having a 1,3,5-triazine ring are 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 polymeric ultraviolet absorber can also be preferably used, and in particular, a polymer type ultraviolet absorber described in JP-A-6-148430 is preferably used. Further, the ultraviolet absorber preferably does not have a halogen group.
Further, it is also preferable to use an ultraviolet absorber and a so-called HALS (hindered amine 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), Tinuvin PA. 144, Tinuvin 765, Tinuvin 770 DF, Tinuvin XT 55 FB, Chimassorb 2020 FDL, Chimassorb 944 FDL, Chimassorb 944 LD, Tinuvin 622 SF, and the like (BASF Japan) (BASF Japan).

The addition method of the ultraviolet absorber, methanol, ethanol, alcohol such as butanol and methylene chloride, methyl acetate, acetone, or an organic solvent such as dioxolane or a mixed solvent thereof is added to the dope after dissolving the ultraviolet absorber in the solvent, Alternatively, it may be added directly in the dope composition.

For inorganic powders that do not dissolve in organic solvents, use a dissolver or sand mill 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 and the use conditions, but when the dry thickness of the acrylic resin film is 15 to 50 μm, it is 0.5 to 10 relative to the acrylic resin film. The range of mass% is preferable, and the range of 0.6 to 4 mass% is more preferable.

(10) Antioxidant 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 be deteriorated.

The antioxidant, for example, has a role of delaying or preventing the decomposition of the acrylic resin film due to the residual solvent amount of halogen in the acrylic resin film or phosphoric acid of the phosphoric acid-based plasticizer. It is preferably contained in the acrylic resin film.

As such an antioxidant, a hindered phenol compound is preferably used, and examples thereof include 2,6-di-t-butyl-p-cresol and 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. In addition, for example, hydrazine-based metal deactivators such as N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine and 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% by mass, more preferably in the range of 10 to 1000 ppm, relative to the acrylic resin film.
In particular, when the recycled material is used, the influence of the resin deterioration due to the heat history becomes large, so that it is preferable to use the above-mentioned antioxidant.

(11) Retardation 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. By compounding the protective film and the retardation derived from the liquid crystal layer, the acrylic resin film can be provided with an optical compensation ability.

Examples of the retardation control agent include aromatic compounds having two or more aromatic rings, such as those described in European Patent 911656A2, rod-shaped compounds described in JP 2006-2025 A, and the like. Moreover, you may use together 2 or more types of aromatic compounds. The aromatic ring of this aromatic compound is preferably an aromatic heterocycle containing an aromatic heterocycle in addition to the aromatic hydrocarbon ring. The aromatic heterocycle is generally an unsaturated heterocycle. Of these, the 1,3,5-triazine ring described in JP-A 2006-2026 is preferable.

Note that the compound having the structure represented by the general formula (A1) also functions as a retardation control agent. Therefore, the compound having the structure represented by the general formula (A1) can impart both functions of retardation control and suppression of optical value fluctuation due to humidity fluctuation with one compound.

The addition amount of these retardation control agents is preferably in the range of 0.5 to 20% by mass, and more preferably in the range of 1 to 10% by mass, relative to 100% by mass of the acrylic resin. ..

(12) Peeling Accelerator As an additive for reducing the peeling resistance of an acrylic resin film, many surfactants have a remarkable effect, and as a preferable peeling agent, a phosphate ester-based surfactant, carboxylic acid or carboxylic acid is used. A salt-based surfactant, a sulfonic acid or sulfonate-based surfactant, and a sulfate ester-based surfactant 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 exemplified 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 O-P(=O)-(OK) ₂
RZ-4 C ₁₅ H ₃₁ (OCH ₂ CH ₂ ) ₅ OP(═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 triisopropylnaphthalene sulfonate RZ-16 Sodium tri-t-butylnaphthalene sulfonate 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, based on the acrylic resin.

<<Physical properties of acrylic resin film>>
(1) Thickness of Acrylic Resin Film The thickness of the finished (dried) 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 liquid crystal The thickness is preferably 20 to 110 μm for a display device, and particularly preferably 20 to 60 μm in view of recent thinning.

The film thickness can be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die die, the extrusion pressure from the die, the metal support speed, etc. so that the desired thickness and the thickness distribution in the present invention can be obtained. Can 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 100 to 10000 m per roll, more preferably 500 to 9000 m, and further preferably 1000 to 8000 m.

(2) Optical Properties of Acrylic Resin Film The preferred optical properties of the acrylic resin film according to the present invention differ depending on the application of the film. In the case of use as a polarizing plate protective film, the absolute value of in-plane retardation (Ro) is preferably 10 nm or less, more preferably 5 nm or less. The absolute value of the retardation (Rt) in the thickness direction is also preferably 50 nm or less, more preferably 35 nm or less, particularly preferably 10 nm or less.

When an acrylic resin film is used as an optical compensation film (retardation film), the range of Ro and Rt differs depending on the type of retardation film, and there are various needs, but 0 nm≦Ro≦100 nm, 40 nm≦Rt≦400 nm Is preferred. 0 nm ≤ Ro ≤ 20 nm, 40 nm ≤ Rt ≤ 80 nm for TN mode, 0 nm ≤ Ro ≤ 20 nm, -30 nm ≤ Rt ≤ 30 nm for IPS mode, and 20 nm ≤ Ro ≤ 80 nm, 80 nm ≤ Rt ≤ 400 nm for VA mode, particularly preferred. The preferable ranges in the VA mode are 30 nm≦Ro≦75 nm and 120 nm≦Rt≦250 nm, and when compensating with one retardation film, 50 nm≦Ro≦75 nm, 180 nm≦Rt≦250 nm, and two phase differences. In the case of compensation with a film, it is more preferable that 30 nm≦Ro≦60 nm and 80 nm≦Rt≦140 nm in the case of a VA mode compensation film in terms of color shift during black display and viewing angle dependence of contrast. is there.

The acrylic resin film according to the present invention can achieve desired optical characteristics by appropriately adjusting process conditions such as a polymer structure to be used, a kind and an addition amount of additives, a draw ratio, and a residual volatile content during peeling. .. For example, the retardation Rt in the thickness direction can be widely controlled to 180 to 300 nm by adjusting the residual solvent amount at the time of peeling within 40 to 85% by mass. Generally, the larger the residual solvent amount at the time of peeling, the smaller the Rt, and the smaller the residual solvent amount at the time of peeling, the larger the Rt. For example, by shortening the drying time on a metal endless support and increasing the residual solvent amount at the time of peeling, it is possible to relax the plane orientation and lower Rt, and by adjusting the process conditions. It is possible to express various retardations according to various uses.

(Retardation, Ro, Rt)
In the present specification, Ro and Rt represent in-plane retardation and retardation in the thickness direction at wavelength λ, respectively. Ro is measured with KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) with light having a wavelength of λ nm incident in the film normal direction. Rt was measured by making light having a wavelength λnm incident from a direction tilted by +40° with respect to the film normal direction with Ro as the tilt axis (rotation axis) using the in-plane slow axis (determined by KOBRA 21ADH). The retardation value and the retardation value measured by injecting light of wavelength λnm from a direction inclined by −40° with respect to the film normal direction with the in-plane slow axis as the inclination 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 Polymer Handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. If the average refractive index value is unknown, it can be measured with an Abbe refractometer. KOBRA 21ADH calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness, and calculates the retardation based on the following formulas (i) and (ii).

Formula (i): Ro=(n _x −n _y )×d (nm)
Formula (ii): Rt={(n _x +n _y )/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 each of them. All are measured values at a wavelength of 590 nm.)
The photoelasticity of the acrylic resin film according to the present invention is preferably 10×10 ⁻¹² /Pa or less, 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-Method for obtaining total light transmittance and 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%, the transparency of the film becomes higher, and there is an advantage that it becomes easier to use as a film for optical use. Furthermore, when the content is less than 0.1%, it is particularly preferably used as a film inside the polarizer of the liquid crystal display (inside the crossed Nicols composed of two polarizers) because depolarization due to light scattering does not occur. To be
The internal haze is usually measured by applying a liquid having the same refractive index as that of the film and covering it with a 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 Industries Co., Ltd.) after conditioning the sample film in an environment of 23° C. and 55% RH for 5 hours or more.
The total light transmittance, the haze, and the internal haze can be adjusted to a preferable range basically by removing the scattering substances 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 or the contacting roll to be in contact, or to adjust the surface shape change due to stretching by the stretching temperature and the magnification. Be seen.

(4) Yellow Index The yellow index (specified in JIS K7373) of the acrylic resin film according to the present invention is preferably less than 3.0. More preferably, it is less than 1.0. The amount of change in the yellow index (so-called ΔYI) when the film is stored under high temperature/high humidity or exposure to ultraviolet rays is preferably less than 5.0.
In order to adjust the yellow index and ΔYI within the preferred range, the type and amount of coloring additives such as UV absorbers are adjusted, decomposition of resins and additives, reactive impurities are reduced as much as possible, and coloring is reduced. It is preferable to add an antioxidant or an ultraviolet absorber for prevention.

(5) Equilibrium Water Content The acrylic resin film of the present invention preferably has an equilibrium water content of 3% or less at 25° C. and a relative humidity of 60%, more preferably 1% or less. By setting the equilibrium water content to 3% or less, it is easy to respond to changes in humidity, and it is more difficult for optical characteristics and dimensions to change, which is preferable.

The equilibrium water content is determined by leaving the sample film in a room conditioned at 23° C. and a relative humidity of 20% for 4 hours or more and then in a room conditioned at 23° C. 80% RH for 24 hours. The moisture is dried and vaporized at a temperature of 150° C. using a meter (for example, CA-20 type manufactured by Mitsubishi Chemical Co., Ltd.) and then quantified by the Karl Fischer method.

(6) Water vapor transmission rate The water vapor transmission rate (specified in JIS K 7129) of the acrylic resin film according to the present invention is preferably 200 g/m ² ·d (40°C · 90% RH) or less. The polarizer protective film is preferably in the range of 50 to 200 g/m ² ·d in order to keep the water content of the polarizer appropriately, and is preferably less than 50 g/m ² ·d for other optical films and electronic circuit board films. .. The adjustment of the film thickness (inversely proportional) is the most effective for adjusting the water vapor transmission rate, but it can also be adjusted by adding a more hydrophilic or hydrophobic additive to the resin of the film. ..

(7) Mechanical Properties The acrylic resin film according to the present invention preferably has a tensile elastic modulus, a tensile breaking strength, and a tensile breaking elongation (defined in JIS K 7127) 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 elongation at break.

Preferable range of tensile modulus: 1.5 to 3.0 GPa
More preferable range of tensile modulus: 2.0 to 2.5 GPa
Preferable range of tensile fracture strength: 30 to 150 MPa
More preferable range of tensile fracture strength: 50 to 100 MPa
Preferable range of tensile breaking elongation: 2 to 15%
More preferable range of tensile elongation at break: 4 to 10%

(8) Dimensional Change The acrylic resin film according to the present invention preferably has a linear expansion coefficient of 50 to 100 ppm/°C in the range of 30°C to 80°C. The expansion coefficient with respect to changes in humidity is preferably less than 50 ppm/%RH (in the range of 23°C 20% to 23°C 80%).
Also, it is preferable that the dimensional change after long-term storage is small, for example, the dimensional change rate before and after storage of a film stored at 80° C. and 90% RH for 500 hours is less than ±1%, and further less than ±0.3%. It is preferable to have.

<<Applications of acrylic resin film>>
The acrylic resin film according to the present invention is an optical film such as a polarizing plate protective film or a retardation film for a liquid crystal display device or an organic electroluminescence display device which is a display device, a base film for a touch panel, a gas barrier base film or the like. Can be suitably used for the base film, the substrate film for nanoimprint, the substrate film for flexible electronic circuits, and the like.

The following describes typical applications such as a polarizing plate protective film, a polarizing plate, a liquid crystal display device, an organic electroluminescent display device, and a gas barrier film.

(1) Polarizing Plate Protective Film and Polarizing Plate A polarizing plate is subjected to at least surface treatment using the acrylic resin film according to the present invention as a polarizing plate protective film, and at least polarized by using water glue or an active energy ray curable adhesive. It is preferably attached to one surface of the child. The acrylic resin film according to the present invention can be similarly bonded to the surface of the polarizer opposite to the surface on 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 attached to the opposite surface of the polarizer with a water paste or an active energy ray-curable adhesive. The acrylic resin film according to the present invention is preferable from the viewpoint of making it possible to further reduce the variation in retardation of the cellulose acylate film with respect to temperature and humidity, and to provide a polarizing plate that is stable against environmental changes and has excellent visibility.

When the polarizing plate is used as the viewing side polarizing plate, the viewing side film of the polarizing plate is preferably provided with a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, an antifouling layer or the like.
[Polarizer]
A polarizer, which is a main component of a polarizing plate, is an element that allows only light having a polarization plane in a certain direction to pass therethrough, and a typical polarizer currently known is a polyvinyl alcohol-based polarizing film. Polyvinyl alcohol-based polarizing films include those obtained by dyeing a polyvinyl alcohol-based film with iodine and those obtained by dyeing a dichroic dye.

As the polarizer, a polarizer obtained by forming a polyvinyl alcohol aqueous solution into a film and uniaxially stretching it for dyeing, or dyeing it and then uniaxially stretching it, and preferably performing durability treatment with a boron compound can be used. The film thickness of the polarizer is preferably 2 to 30 μm, and particularly preferably 2 to 15 μm.

Further, the content of ethylene units described in JP-A-2003-248123 and JP-A-2003-342322 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 %. The ethylene-modified polyvinyl alcohol of is also preferably used. Above all, an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature of 66 to 73° C. is preferably used. A polarizer using this ethylene-modified polyvinyl alcohol film is excellent in polarization performance and durability performance, has less color unevenness, and is particularly preferably used for a large-sized liquid crystal display device.

<Multilayer film type polarizer>
The polarizing plate is preferably a thin film, and the thickness of the polarizer is particularly preferably in the range of 2 to 15 μm from the viewpoint of achieving both strength and thinning of the polarizing plate.

As such a thin film polarizer, a laminated film type polarizer is produced by the method described in JP 2011-100161 A, JP 4691205 A, JP 4751481 A, and JP 4804589 A. Is preferred.

As an example, it is preferable to use a thin film laminated film type polarizer (polarizing laminated film) manufactured by the following steps from the viewpoint that the entire thickness of the polarizing plate can be reduced and the weight can be reduced.

(Method for manufacturing a polarizing laminated film)
The method for producing a polarizing laminated film used in the present invention includes the following steps.
(A) a laminating step in which a polyvinyl alcohol-based resin layer is formed on one surface of a substrate film in which a rubber component is dispersed in a thermoplastic resin to obtain a laminated film,
(B) a stretching step of uniaxially stretching the laminated film to obtain a stretched film,
(C) a dyeing step of dyeing the polyvinyl alcohol resin layer of the stretched film with a dichroic dye to obtain a dyed film,
(D) The polyvinyl alcohol-based resin layer of the dyed film is immersed in a solution containing a crosslinking agent to form a polarizer layer, and a crosslinking step of obtaining a crosslinked film, and (e) a drying step of drying the crosslinked film Explaining the process,
(A) Laminating step In this step, a film obtained by dispersing (blending) a rubber component in a thermoplastic resin is used as a base film, and a polyvinyl alcohol resin layer is formed on one surface of the base film to obtain a laminated film. Is preferred.

(Base film)
The thermoplastic resin serving as the base of the base film is preferably a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, stretchability and the like. Specific examples of such a thermoplastic resin include, for example, chain polyolefin resin; cyclic polyolefin resin; (meth)acrylic resin; polyester resin; cellulose acylate resin; polycarbonate resin; polyvinyl alcohol resin. Resins; vinyl acetate resins; polyarylate resins; polystyrene resins; polyether sulfone resins; polysulfone resins; polyamide resins; polyimide resins; and mixtures or copolymers thereof.

The rubber component dispersed in the thermoplastic resin is a resin component having rubber elasticity, and is usually uniformly dispersed as rubber particles in the thermoplastic resin. By mixing and dispersing the rubber component, it is possible to improve the tear strength of the base film, and thus the stretched film. The rubber component is not particularly limited as long as it is a resin having rubber elasticity, but from the viewpoint of compatibility with the thermoplastic resin, the rubber component is preferably composed of the same or similar resin as the thermoplastic resin used.

For example, when the thermoplastic resin is a chain polyolefin resin, the rubber component can be a copolymer of two or more 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, and 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 containing alkyl acrylate, and may be a homopolymer of alkyl acrylate, or 50% by mass or more of alkyl acrylate and 50% by mass or less of other monomer. It may be a copolymer of

The compounding amount of the rubber component is preferably 5 to 50% by mass of the thermoplastic resin, and more preferably 10 to 45% by mass. If the blending amount of the rubber component is too small, a sufficient effect of improving the tear strength tends to be difficult to obtain, and if the blending amount of the rubber component is too large, the handleability of the base film tends to decrease.

The method of dispersing the rubber component in the thermoplastic resin is not particularly limited. For example, a method of kneading the separately prepared thermoplastic resin and the rubber component (rubber particles) by a plastomill or the like, or the same reaction when preparing the thermoplastic resin A reactor blend method in which a rubber component is also prepared in a container to obtain a thermoplastic resin in which the rubber component is dispersed can be used. 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 a polyvinyl alcohol resin and its derivatives. Derivatives of polyvinyl alcohol resins include polyvinyl formal and polyvinyl acetal, as well as polyvinyl alcohol resins such 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. , Those modified with acrylamide and the like. Among these, it is preferable to use polyvinyl alcohol resin.

The polyvinyl alcohol resin is preferably a completely saponified product. The range of the degree of saponification is preferably 80.0 to 100.0 mol%, more preferably 90.0 to 99.5 mol%, and further preferably 94.0 to 99.0. It is in the range of mol %.

If necessary, additives such as a plasticizer and a surfactant may be added to the above-mentioned polyvinyl alcohol resin. As the plasticizer, polyol and its condensate can be used, and examples thereof include glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, polyethylene glycol and the like. The amount of the additive compounded is not particularly limited, but is preferably 20% by mass or less of the polyvinyl alcohol resin.

The method for applying the polyvinyl alcohol-based resin solution to the substrate film includes 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 resin layer in the laminated film is preferably 3 μm or more and 50 μm or less, 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 dyeing property is significantly deteriorated, and if it exceeds 50 μm, the polarizing laminate film obtained becomes thick.

The thickness of the polyvinyl alcohol-based resin layer as the polarizer used in the present invention is within the range of 2 to 15 μm as the film thickness after the following stretching treatment from the viewpoints of thinning and strength and flexibility as the polarizer. Is preferred.

(B) Stretching Step This step is a step of uniaxially stretching a laminated film including a substrate film and a polyvinyl alcohol resin layer to obtain a stretched film. The stretching ratio of the laminated film can be appropriately selected according to the desired polarization characteristics, but it is preferably in the range of 5 to 17 times, and more preferably 5 to 8 times the original length of the laminated film. It is within the range.

The stretching is preferably longitudinal stretching in which the laminated film is stretched in the longitudinal direction (film transport direction). Examples of the longitudinal stretching method include inter-roller stretching method, compression stretching method, and stretching method using a tenter. The uniaxial stretching is not limited to the longitudinal stretching process and may be oblique 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 pigment include iodine and organic dyes. As the organic dye, for example, 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, 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 add iodide to the iodine-containing dyeing solution because the dyeing efficiency can be further improved. Examples of the 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 resin layer of the dyed film obtained by dyeing with a dichroic dye is subjected to a crosslinking treatment to form a crosslinked film having the polyvinyl alcohol resin layer as a polarizer layer. It is a process of obtaining. The crosslinking step can be performed, for example, by immersing the dyed film in a solution containing a crosslinking agent (crosslinking solution). A conventionally known substance can be used as the crosslinking agent. Examples thereof include boron compounds such as boric acid and borax, glyoxal, and glutaraldehyde. These may be used alone or in combination of two or more.

(E) Drying step The obtained crosslinked film is usually washed and then dried. Thereby, a polarizing laminated film is obtained. The washing can be performed by immersing the crosslinked film in pure water such as ion-exchanged water or distilled water. The water washing temperature is usually in the range of 3 to 50°C, preferably 4 to 20°C. The immersion 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 washing treatment with water, and it is also possible to use a solution in which a liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol or propanol is appropriately mixed.

As the drying method, any appropriate 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 has a polarizer layer composed of a polyvinyl alcohol resin layer in which a dichroic dye is adsorbed and oriented, and can be used as a polarizing plate itself. As a preferred embodiment of the present invention, after the polarizing laminate film is formed by the above steps, the polyvinyl alcohol layer of the polarizing laminate film is peeled from the substrate film to use the polyvinyl alcohol layer as a polarizer. That is. According to this method, since the thickness of the polarizer layer can be set to 15 μm or less, a thin polarizer can be obtained. Further, the polarizer used in the present invention is also excellent in polarization performance and durability.

[Production of polarizing plate]
The polarizing plate can be manufactured by a general method. It is preferable that the polarizer side of the acrylic resin film according to the present invention is surface-treated, and the resulting active energy ray-curable adhesive is used to bond with a polarizer prepared by dipping and stretching in an iodine solution. Further, when a cellulose acylate film is used on the surface opposite to the surface on which the acrylic resin film is attached, the cellulose acylate film is subjected to alkali saponification treatment, and at least one surface of the polarizer is completely saponified. It is preferable to bond them by using an aqueous polyvinyl alcohol solution (water glue). Another polarizing plate protective film can be attached to the other surface.

For example, commercially available cellulose acylate films (for example, Konica Minolta Tuck KC8UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC6UY, KC6UA, KC4UY, KC4UE, KC8UE, KC8UY-HA, XUUR, KC8UE, KC8UY-HA, UC, UC, UC, XC, UC, XC, UC, XC, XC, XC, XC, XC, XC, XC, X, X, X, X, X, X, X, X, X, X, X, X, X, Y, X, X, X, X, Y, X, X, Y, X, X, X, Y, X, X, Y, X, Y, X, X, Y, X, X, Y, Y, X, Y, Y, Y, Y, Y, Y, Y, Y, Y, Y. KC8UXW-RHA-NC, KC4UXW-RHA-NC, manufactured by Konica Minolta Co., Ltd. are preferably used.
In addition, various grades of Cosmo Shine (R) Super Birefringence Type (SRF) manufactured by Toyobo Co., Ltd. and Cycloolefin Polymer (COP) molded product-Zeonor 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 a 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 according to the present invention and the polarizer are attached to each other 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 the acrylic resin film and the polarizer, it is possible to obtain a polarizing plate having high strength and excellent flatness even with a thin film.

<Composition of UV curable adhesive>
As the ultraviolet curable adhesive composition for a polarizing plate, a photoradical polymerization type composition utilizing photoradical polymerization, a photocationic polymerization type composition utilizing photocationic polymerization, and a combination of photoradical polymerization and photocationic polymerization are used. Hybrid type compositions are known.

The photo-radical-polymerizable composition contains a radical-polymerizable compound containing a polar group such as a hydroxy group or a carboxy group and a radical-polymerizable compound not containing a polar group described in JP-A-2008-009329 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 the compound having a radically polymerizable ethylenically unsaturated bond include a compound having a (meth)acryloyl group. Examples of compounds having a (meth)acryloyl group include N-substituted (meth)acrylamide compounds and (meth)acrylate compounds. (Meth)acrylamide means acrylamide or methacrylamide.

Further, as the photocationic polymerization type composition, (α) cationically polymerizable compound, (β) photocationic polymerization initiator, (γ) wavelength longer than 380 nm as disclosed in JP 2011-028234A An ultraviolet-curable adhesive composition containing each component of a photosensitizer that exhibits maximum absorption for light and (δ) a naphthalene-based photosensitization aid. However, other UV curable adhesives may be used.

(I) Pretreatment Step The pretreatment step is a step of performing an easy-adhesion treatment on the adhesive surface of the acrylic resin film with the polarizer. Examples of the easy adhesion treatment include corona treatment and plasma treatment.

(Application 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 bonding surfaces of the polarizer and the acrylic resin film. When the ultraviolet curable adhesive is directly applied to the surface of the polarizer or the acrylic resin film, the application method is not particularly limited. For example, various wet coating methods such as doctor blade, wire bar, die coater, comma coater and gravure coater can be used. Alternatively, a method in which an ultraviolet-curable adhesive is cast between the polarizer and the acrylic resin film and then pressure is applied with a roller or the like to uniformly spread it can be used.

(Ii) Laminating Step After applying the ultraviolet curable adhesive by the above method, it is treated in the laminating step. In this laminating step, for example, when the surface of the polarizer is coated with the ultraviolet curable adhesive in the previous coating step, the acrylic resin film is superposed thereon. Further, in the case of a system in which an ultraviolet curable adhesive is first applied to the surface of an acrylic resin film, a polarizer is superposed on it. Further, when the ultraviolet curable adhesive is cast between the polarizer and the acrylic resin film, the polarizer and the acrylic resin film are superposed in that state. Then, in this state, the pressure is normally applied by sandwiching the acrylic resin film on both sides with a pressure roller or the like. The pressure roller can be made of metal, rubber, or the like. The pressure rollers arranged on both sides may be made of the same material or different materials.

(Iii) Curing step In the curing step, the uncured ultraviolet curable adhesive is irradiated with ultraviolet rays to generate a cationically polymerizable compound (for example, an epoxy compound or an oxetane compound) or a radically polymerizable compound (for example, an acrylate compound, acrylamide). The ultraviolet curable adhesive layer containing a system compound or the like) is cured, and the laminated polarizer and the acrylic resin film are adhered via the ultraviolet curable adhesive. When the acrylic resin film is attached to one surface of the polarizer, the active energy ray may be irradiated from either the polarizer side or the acrylic resin film side. Also, when laminating acrylic resin films on both sides of the polarizer, the acrylic resin films are superposed on both sides of the polarizer with ultraviolet curable adhesives, respectively, and then irradiated with ultraviolet rays to cure ultraviolet rays on both sides. It is advantageous to cure the adhesive at the same time.

Any appropriate condition can be adopted as the irradiation condition of the ultraviolet light as long as it can cure the ultraviolet curing adhesive applied to the present invention. 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 ~ 500mJ / cm ^2.

When the production process of the polarizing plate is performed in 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 5 to 300 m/min, and further preferably 10 to It is in the range of 100 m/min. When the line speed is 1 m/min or more, productivity can be secured, or damage to the acrylic resin film can be suppressed, and a polarizing plate excellent in durability can be manufactured. Further, when the line speed is 500 m/min or less, the ultraviolet curable adhesive is sufficiently cured, and the 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 hard coat layer, an antistatic layer and the like as functional layers.

<Antireflection layer>
It is preferable to provide a functional film such as an antireflection layer on the transparent protective film disposed on the opposite side of the polarizing plate from 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 middle 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)
Matt particles are preferably dispersed in the light-scattering layer, and the material other than the mat particles in the light-scattering layer preferably has a refractive index in the range of 1.50 to 2.00. The refractive index of is preferably in the range of 1.35 to 1.49. The light scattering layer may have both an antiglare property and a hard coat property, and may be a single layer or may be composed of a plurality of layers, for example, 2 to 4 layers.

The surface roughness of the antireflection layer is such that the center line average roughness Ra is 0.08 to 0.40 μm, the 10-point average roughness Rz is 10 times or less than Ra, the average peak-valley distance Sm is 1 to 100 μm, and the maximum unevenness is Designed so that the standard deviation of the height of the convex portion from the portion is 0.5 μm or less, the standard deviation of the average peak-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 properties and a uniform matt feeling by visual observation can be achieved, which is preferable.

In addition, the ratio of the minimum value and the maximum value of the reflectance within the range of a ^* value −2 to 2, b ^* value −3 to 380 to 780 nm under the C light source is 0.5. When the ratio is up to 0.99, the tint of the reflected light becomes neutral, which is preferable. Further, by setting the b ^* value of the transmitted light under the C light source to be 0 to 3, the yellow tint of white display when applied to a display device is reduced, which is preferable.

Further, when a 120×40 μm grating is inserted between the surface light source and the antireflection film to measure the luminance distribution on the film, the standard deviation of the luminance distribution is 20 or less. Glitter when the acrylic resin film is applied is reduced, which is preferable.

The optical properties of the antireflection layer are such that the specular reflectance is 2.5% or less, the transmittance is 90% or more, and the 60 degree glossiness is 70% or less, whereby the reflection of external light can be suppressed and the visibility is improved. Therefore, it is preferable. In particular, the specular reflectance is more preferably 1% or less, and most preferably 0.5% or less. Haze 20 to 50%, internal haze/total haze value (ratio) of 0.3 to 1, reduction of haze value after formation of the low refractive index layer within 15% from the haze value up to the light scattering layer, comb width 0 20% to 50% transmitted image clarity at 0.5 mm, and 1.5 to 5.0 transmittance ratio in the direction of vertical transmitted light/2° tilt from vertical to prevent glare on high-definition LCD panels It is preferable because reduction of blurring 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 1.30 to 1.44. Furthermore, it is preferable that the low refractive index layer satisfy the following formula from the viewpoint of lowering the reflectance.

(M/4)×0.7<n1d1<(m/4)×1.3
In the formula, 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 materials for 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 dynamic friction coefficient of 0.03 to 0.20, a contact angle to water of 90 to 120°, and a sliding angle of pure water of 70° or less and which is crosslinked by heat or ionizing radiation is preferable. When the antireflection film is attached to the image display device, the lower the peeling force from the commercially available adhesive tape is, the easier it is to peel off after sticking a seal or a memo, preferably 500 gf or less, more preferably 300 gf or less, more preferably 100 gf or less. Most preferred.

Further, the higher the surface hardness measured with a micro hardness meter, the more difficult it is to be scratched, 0.3 GPa or more is preferable, and 0.5 GPa or more is more preferable.

Examples of the fluoropolymer used in the low refractive index layer include hydrolysis and dehydration condensation products of perfluoroalkyl group-containing silane compounds (eg (heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane). And a fluorine-containing copolymer containing a fluorine-containing monomer unit and a constitutional unit for imparting crosslinking reactivity as constitutional components.

Specific examples of the fluorine-containing monomer include, for example, fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc. ), partially or fully fluorinated alkyl ester derivatives of (meth)acrylic acid (for example, biscoat 6FM (manufactured by Osaka Organic Chemical Co., Ltd.) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, and the like. Of these, perfluoroolefins are preferable, and hexafluoropropylene is particularly preferable from the viewpoints of refractive index, solubility, transparency, availability, and the like.

As the constitutional unit for imparting cross-linking reactivity, glycidyl (meth)acrylate, a constitutional unit obtained by polymerization of a monomer having a self-crosslinking functional group in the molecule such as glycidyl vinyl ether, a carboxy group, a hydroxy group, an amino group , A monomer having a sulfo group and the like (for example, (meth)acrylic acid, methylol (meth)acrylate, hydroxyalkyl (meth)acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.) Structural units, and structural units in which a cross-linking reactive group such as a (meth)acryloyl group is introduced into these structural units by a polymer reaction (for example, it can be introduced by a method of causing acrylic acid chloride to act on a hydroxy group) Is mentioned.

In addition to the above-mentioned fluorine-containing monomer unit and the constitutional unit for imparting cross-linking reactivity, a monomer not containing a fluorine atom can be appropriately copolymerized from the viewpoints of solubility in a solvent, transparency of a film and the like. The monomer unit that can be used in combination is not particularly limited, and examples thereof include olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic acid esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2 -Ethylhexyl), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (N-tert-butyl acrylamide, N-cyclohexyl acrylamide etc.), methacrylamides, acrylonitrile Examples thereof include derivatives. A curing agent may be appropriately used in combination with the above polymer as described in JP-A-10-25388 and JP-A-10-147739.

(Light scattering layer)
The light-scattering layer is generally formed for the purpose of contributing to the film a light-diffusing property due to surface scattering and/or internal scattering, and a hard coat property for improving scratch resistance of the film. Therefore, in general, a binder for imparting hard coat properties, matte particles for imparting light diffusivity, and optionally an inorganic filler for increasing the refractive index, preventing cross-linking shrinkage, and increasing the strength are formed. To be done. The thickness of the light-scattering layer is preferably from 1 to 10 μm, more preferably from 1.2 to 6 μm, from the viewpoint of imparting a hard coat property and suppressing curling and deterioration of brittleness.

The binder for the scattering layer is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. Further, the binder polymer preferably has a crosslinked structure. The binder polymer having a saturated hydrocarbon chain as the main chain is preferably a polymer of ethylenically unsaturated monomers. 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, one having 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 in the structure of this monomer is used. 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( (Meth)acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra(meth)acrylate), pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(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) , Above-mentioned ethylene oxide modified products, vinylbenzene and its derivatives (eg 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg divinyl sulfone) , Acrylamide (eg methylenebisacrylamide) and methacrylamide. Two or more of the above 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 kinds of these monomers may be used in combination.

The polymerization of these ethylenically unsaturated group-containing monomers 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 liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support after ionizing radiation or heat. It is possible to form an antireflection film by being cured by the polymerization reaction of. Known photo-radical initiators and the like can be used.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be carried out by irradiation with ionizing radiation or heating in the presence of a photo-acid generator or a thermal-acid generator.

Therefore, a coating solution containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, mat particles and an inorganic filler is prepared, and the coating solution is applied on a transparent support by a polymerization reaction by ionizing radiation or heat. It can be cured to form an antireflection film.

Instead of or in addition to the monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by the reaction of the crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.

Examples of the crosslinkable functional group include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxy group, a methylol group and an active methylene group. Vinyl sulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. You may use the functional group which shows a crosslinkability as a result of a decomposition reaction like a block isocyanate group. That is, in the present invention, the crosslinkable functional group may be one that does not immediately show a reaction but shows reactivity as a result of decomposition.

A crosslinked structure can be formed by heating the binder polymer having these crosslinkable functional groups after coating.

For the purpose of imparting antiglare properties, the light scattering layer has matting particles larger than the filler particles and having an average particle size in the range of 1 to 10 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or It is preferable that resin particles are contained.

Specific examples of the matte particles include particles of inorganic compounds 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. 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 may be either spherical or amorphous.

Also, 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 having a larger particle size and impart other optical properties with matt particles having a smaller particle size.

Furthermore, the particle size distribution of the above matte particles is most preferably monodisperse, and the closer the particle sizes of the particles are, the better. For example, when a particle having a particle diameter larger than the average particle diameter by 20% or more is defined as a coarse particle, the proportion of the coarse particle is preferably 1% or less of the total number of particles, more preferably 0.1%. It is below, and more preferably 0.01% or below. The 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 such that the amount of matte particles in the formed light-scattering layer is preferably in the range of 10 to 1000 mg/m ² , and more preferably 100 to 700 mg/m ² . The particle size distribution of matte particles is measured by the Coulter counter method, and the measured distribution is converted into a particle number distribution.

In order to increase the refractive index of the layer, the light-scattering layer contains, in addition to the matte particles described above, an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony. Therefore, it is preferable to contain an inorganic filler having an average particle diameter of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less.

On the contrary, in order to increase the refractive index difference with 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 preferable 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 also preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treating agent having a functional group capable of reacting with a binder species on the filler surface is preferably used. The addition amount of these inorganic fillers 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%. is there. In addition, since such a filler has a particle diameter sufficiently smaller than the wavelength of light, scattering does not occur, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

The bulk refractive index of the mixture of the binder and the inorganic filler in the light scattering layer is preferably in the range of 1.48 to 2.00, more preferably 1.50 to 1.80. In order to make the refractive index within the above range, the kind and the ratio of the amount of the binder and the inorganic filler may be appropriately selected. How to select can be easily known in advance experimentally.

The light-scattering layer is coated with a fluorine-based or silicone-based surfactant, or both of them 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 the effect of improving surface defects such as coating unevenness, drying unevenness, point defects and the like of the antireflection film appears with a smaller addition amount. The purpose is to improve productivity by imparting suitability for high speed coating while improving surface uniformity.

<Antireflection 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 consisting of at least a medium-refractive-index layer, a high-refractive-index layer, and a low-refractive-index layer (outermost layer) on the film must be designed to have a refractive index that satisfies the following relationships. Is preferred. High refractive index layer refractive index> Medium refractive index layer refractive index> Transparent support refractive index> Low refractive index layer refractive index. 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, JP-A-8-122504, JP-A-8-110401, JP-A-10-300902, and Unexamined Japanese Patent Publication No. 2002-243906, Japanese Unexamined Patent Publication No. 2000-111706, etc.). Further, other functions may be imparted to each layer, for example, a low-refractive index layer having an antifouling property and a high-refractive index layer having an antistatic property (eg, JP-A-10-206603, JP-A-2002-2002). 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 a 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 particle having a high refractive index having an average particle diameter of 100 nm or less and a matrix binder.

Examples of the high-refractive-index inorganic compound fine particles include inorganic compounds having a refractive index of 1.65 or more, and preferably those having a refractive index of 1.9 or more. Examples thereof include oxides of Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, In and the like, and complex oxides containing these metal atoms.

In order to obtain such ultrafine particles, the surface of the particles should 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). , An anionic compound or an organometallic coupling agent: JP-A-2001-310432, etc.), and a core-shell structure having high refractive index particles as a core (: JP-A-2001-166104 and 2001-310432). Gazette), a specific dispersant combination (eg, JP-A No. 11-153703, US Pat. No. 6,210,858, etc.) and the like.

As the material for forming the matrix, conventionally known thermoplastic resins, curable resin films, etc. may be mentioned.

Furthermore, from a polyfunctional compound-containing composition having at least two radically polymerizable and/or cationically polymerizable polymerizable groups, and a composition containing an organometallic 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 Nos. 2000-47004, 2001-315242, 2001-31871, 2001-296401, etc. may be mentioned.

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 Japanese Patent Laid-Open No. 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, more preferably 10 nm to 1 μm. The refractive index of the medium refractive index layer is adjusted 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, more preferably 10 nm to 1 μm.

(Low refractive index layer)
In the above structure, 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 1.30 to 1.50.

It is preferable to build it as the outermost layer having scratch resistance and antifouling property. As a means for greatly improving the scratch resistance, it is effective to impart slipperiness to the surface, and conventionally known means for forming a thin film layer such as introduction of silicone and introduction of fluorine can be applied.

The refractive index of the fluorine-containing compound is preferably in the range of 1.35 to 1.50. The range is more preferably 1.36 to 1.47. Further, the fluorine-containing compound is preferably a compound containing a fluorine atom in the range of 35 to 80 mass% and having a crosslinkable or polymerizable functional group. For example, paragraph numbers [0018] to [0026] in JP-A-9-222503, paragraph numbers [0019] to [0030] in JP-A No. 11-38202, paragraph numbers in JP-A-2001-40284. The compounds described in [0027] to [0028] and JP-A No. 2000-284102 are mentioned.

The silicone compound is a compound having a polysiloxane structure, and a compound having a curable functional group or a polymerizable functional group in the polymer chain and having a crosslinked structure in the film is preferable. Examples thereof include reactive silicones (eg, Silaplane (manufactured by Chisso Corp.), polysiloxanes containing silanol groups at both ends (JP-A-11-258403, etc.), and the like.

The fluorine-containing and/or siloxane polymer having a crosslinkable or polymerizable group is crosslinked or polymerized at the same time as or after the application of the coating composition for forming the outermost layer containing a polymerization initiator, a sensitizer and the like. It is preferably carried out by irradiation with light or heating.

Also preferred is a sol-gel cured film in which an organometallic 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 presence of a catalyst.

For example, a polyfluoroalkyl group-containing silane compound or a partial hydrolysis-condensation product thereof (JP-A-58-142958, JP-A-58-147483, JP-A-58-147484, JP-A-9-157582 and JP-A-9-157582). -106704, etc.), a silyl compound containing a poly "perfluoroalkyl ether" group, which is a long-chain fluorine-containing group (JP-A-2000-117902, 2001-48590 and 2002-). Compounds described in Japanese Patent No. 53804) and the like.

The low refractive index layer has a primary particle average diameter of 1 to 150 nm as an additive other than the above, such as a filler (eg, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)). A low refractive index inorganic compound, organic fine particles described in paragraph Nos. [0020] to [0038] of JP-A No. 11-3820, etc.), a silane coupling agent, a slipping agent, a surfactant and the like can be contained.

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 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 forward scattering layer, a primer layer, an antistatic layer, an undercoat layer or a protective layer 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 preferably provided between the transparent support and the high refractive index layer. The hard coat layer is preferably formed by a crosslinking 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 organic alkoxysilyl compound.

Specific examples of these compounds include the same as those exemplified for the high refractive index layer. Specific examples of the constituent composition of the hard coat layer include those described in JP-A Nos. 2002-144913, 2000-9908, and WO 00/46617.

The high refractive index layer can double as a hard coat layer. In such a case, it is preferable that fine particles are finely dispersed by using the method described for the high refractive index layer and contained in the hard coat layer.

The hard coat layer can also serve as an antiglare layer (described later) in which particles having an average particle size of 0.2 to 10 μm are contained to impart an antiglare function (antiglare function).

The thickness of the hard coat layer can be designed appropriately according to the application. The thickness of the hard coat layer is preferably in the range of 0.2 to 10 μm, more preferably 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 a pencil hardness test according to JIS K5400. Also, in the Taber test according to JIS K5400, it is preferable that the wear amount 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 with a volume resistivity of 10 ⁻⁸ Ω·cm ⁻³ or less. A volume resistivity of 10 ⁻⁸ Ω·cm ⁻³ can be provided by using hygroscopic substances, water-soluble inorganic salts, certain surfactants, cationic polymers, anionic polymers, colloidal silica, etc. There is a problem that it is highly dependent and sufficient conductivity cannot be ensured at low humidity. Therefore, a metal oxide is preferable as the conductive layer material. It is preferable to use an uncolored metal oxide as the material for the conductive layer because the coloring of the entire film can be suppressed. Zn, Ti, Al, In, Si, Mg, Ba, Mo, W, or V can be given as a metal forming the uncolored metal oxide, and a metal oxide containing this as a main component can be used. preferable. As a specific example, 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 a composite oxide of these is preferable. Particularly, ZnO, TiO ₂ , and SnO ₂ are preferable. Examples of containing different kinds of atoms include, for example, additives such as Al and In for ZnO, addition of Sb, Nb, halogen elements and the like for SnO ₂ , and addition of Nb, TA, etc. for TiO ₂ . Addition is effective. Furthermore, as described in JP-B-59-6235, a material in which the above metal oxide is attached to other crystalline metal particles or fibrous substances (for example, titanium oxide) may be used. Note that the volume resistance value and the surface resistance value are different physical property values and cannot be simply compared, but in order to secure the conductivity of 10 ⁻⁸ Ω·cm ⁻³ or less in terms of the volume resistance value, It suffices that the layer has a surface resistance value of approximately 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 attached for a 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 driving systems such as STN, TN, OCB, HAN, VA (MVA, PVA), IPS, OCB. A VA (MVA, PVA) type liquid crystal display device is preferable.

A liquid crystal display device usually uses two polarizing plates, a polarizing plate on the viewing side and a polarizing plate on the backlight side. However, a polarizing plate provided with the acrylic resin film according to the present invention is used as both polarizing plates. Is also preferable, and 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 visible side that directly contacts the external environment, in which case a retardation film such as a cellulose acylate film is arranged on the liquid crystal cell side. It is preferable.

The polarizing plate on the backlight side may be a polarizing plate that does not include the acrylic resin film according to the present invention. In that case, both surfaces of the polarizer may be coated with, for example, a commercially available cellulose acylate film (for example, Konica Minolta Tuck KC8UX). , KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UA, KC2UAH, KC4UAH, KC6UAH, or Konica Minolta (strain ), Fujitac T40UZ, Fujitac T60UZ, Fujitac T80UZ, Fujitac TD80UL, Fujitac TD60UL, Fujitac TD40UL, Fujitac R02, Fujitac R06, Fujifilm (manufactured by Fuji Film Co., Ltd., etc.) are preferably used.

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 polarizer, and the commercially available cellulose acylate film, polyester film, acrylic film, or polycarbonate film on the opposite side. A laminated 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 for an organic electroluminescence display device as well as a liquid crystal display device. For example, the cyclic polyolefin film of the present invention is stretched obliquely at 45° with respect to the transport direction described above, and is laminated with a polarizer having an absorption axis in the transport direction by roll-to-roll to form a 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.

Also, the acrylic resin film according to the present invention is preferably used as a flexible substrate of an organic electroluminescence element, and in that case, it is preferably applied as a gas barrier film described later.

Regarding the specific layer structure, members, manufacturing method, and the like of the organic EL element, JP 2011-238355 A, JP 2013-077585 A, JP 2013-187090 A, JP 2013-229202 A, See JP-A-2013-232320 and JP-A-2014-026853 for details, which can be referred to.

(4) Gas Barrier Film It is preferred to form a film of an inorganic material or an organic material or a hybrid film of both of them on the surface of the acrylic resin film according to the present invention to use as a gas barrier film.

The gas barrier property is a water vapor permeability (25±0.5° C., relative humidity (90±2)%) of 0.01 g/(m ² ·24 h) measured by a method according to JIS K 7129-1992. The film having the following gas barrier layer is preferable, and further, the oxygen permeability measured by a method according to JIS K 7126-1987 is 1×10 ⁻³ ml/(m ² ·24 h·atm). Hereafter, it is preferable that the film has a high gas barrier property with a water vapor permeability of 1×10 ⁻⁵ g/(m ² ·24 h) or less.

The method for forming the gas barrier layer applicable to the present invention is not particularly limited, but for example, a sputtering method (eg, magnetron cathode sputtering, flat plate magnetron sputtering, 2-pole AC flat plate magnetron sputtering, 2-pole AC rotary magnetron sputtering, etc.). , Evaporation method (eg resistance heating evaporation, electron beam evaporation, ion beam evaporation, plasma assisted evaporation, etc.), thermal CVD method, catalytic chemical vapor deposition method (Cat-CVD), capacitive coupling plasma CVD method (CCP-CVD) Examples include chemical vapor deposition methods such as photo-CVD method, plasma CVD method (PE-CVD), epitaxial growth method, atomic layer growth method, and reactive sputtering method.

Also, 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 formed, for example, by coating an organic monomer or organic 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 crosslinking if necessary. It can also be formed, for example, by depositing an organic monomer or organic oligomer capable of flash evaporation and radiation crosslinking and then forming a polymer from the organic monomer or oligomer. The coating efficiency can be improved by cooling the resin substrate.

Examples of the method for applying the organic monomer or 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 laminates 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.

Furthermore, a method of forming an inorganic gas barrier layer by performing wet coating on a support with a coating solution containing an inorganic precursor such as polysilazane or tetraethyl orthosilicate (TEOS), and then performing modification treatment by irradiating vacuum ultraviolet light or the like. The inorganic gas barrier layer is also formed by a film metallization technique such as metal plating on a resin substrate or bonding a metal foil to a resin substrate.

Further, a method of forming an inorganic gas barrier layer by performing wet coating on a support with a coating solution containing an inorganic precursor such as polysilazane or tetraethyl orthosilicate (TEOS), and then performing modification treatment by irradiating vacuum ultraviolet light or the like. The inorganic gas barrier layer is also formed by a film metallization technique such as metal plating on a resin substrate or bonding a metal foil and a resin substrate.

An example of the inorganic gas barrier layer formed using the plasma CVD method will be described below.

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 it is provided with at least a pair of film forming rollers and a plasma power source, and a pair of forming rollers. It is preferable that the apparatus has a structure capable of discharging between the film rollers. For example, when the manufacturing apparatus shown in FIG. 41 is used, the manufacturing is performed by the roll-to-roll method while using the 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. 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, transport rollers C33, C34, C35 and C36, film forming rollers C39 and C40, a gas supply pipe C41, a plasma generating power source C42, and a film forming roller. The magnetic field generator C43 and C44 installed inside C39 and C40, and the winding roller C45 are provided.

Further, in such a manufacturing apparatus C31, at least the film forming rollers C39 and C40, the gas supply pipe C41, the plasma generating power source C42, and the magnetic field generating apparatuses 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 inside the vacuum chamber can be appropriately adjusted by the vacuum pump.

In such a manufacturing apparatus C31, each film forming roller is connected to the plasma generating power source C42 so that the pair of film forming rollers (film forming rollers C39 and C40) can function as a pair of opposing electrodes. It is connected. Therefore, in such a manufacturing apparatus C31, by supplying electric power from the plasma generation power source C42, it is possible to discharge into the space between the film forming roller C39 and the film forming roller C40, and thereby, Plasma can be generated in the space between the film roller C39 and the film formation roller C40.

When the film-forming roller C39 and the film-forming roller C40 are also used as electrodes in this way, the material and design 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 such that their central axes are substantially parallel on the same plane. By thus disposing the pair of film forming rollers (film forming rollers C39 and C40), 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. Since it is possible to deposit the inorganic gas barrier layer component on the surface of C2 and further deposit the inorganic gas barrier layer component on the surface of the resin substrate C2 also on the film forming roller C40, it is possible to deposit the inorganic gas barrier layer component 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, which are fixed so as not to rotate even if the film forming rollers rotate, are provided, respectively.

The magnetic field generators C43 and C44 provided on the film forming rollers C39 and C40 respectively include a magnetic field generator C43 provided on one film forming roller C39 and a magnetic field generator C44 provided on the other film forming roller C40. It is preferable to arrange the magnetic poles so that the magnetic lines of force do not cross each other 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 the lines of magnetic force swell near the opposing surfaces of the film forming rollers C39 and C40, and the plasma is converged on the swelling portion. Since it becomes easier, it is excellent in that the film forming efficiency can be improved.

The magnetic field generators C43 and C44 provided on the film forming rollers C39 and C40, respectively, are provided with racetrack-shaped magnetic poles that are long in the roller axis direction, and one magnetic field generator C43 and the other magnetic field generator C44 are separated 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 do not straddle the magnetic field generators on the roller side where the lines of magnetic force face each other, and the opposing space is provided along the length direction of the roller shaft. A racetrack-shaped magnetic field can be easily formed near the roller surface facing the (discharge area), and the plasma can be converged to the magnetic field, so that a wide resin wrapped along the roller width direction. It is excellent in that the inorganic gas barrier layer C4, which is a vapor deposition film, can be efficiently formed using the substrate C2.

As the film forming rollers C39 and C40, known rollers can be appropriately used. It is preferable to use the film forming rollers C39 and C40 having the same diameter from the viewpoint that a thin film can be formed more efficiently.

The diameters of the film forming rollers C39 and C40 are preferably in the range of 300 to 1000 mmφ, and particularly preferably 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, the productivity is not deteriorated, and it is possible to avoid that the total heat of plasma discharge is applied to the resin substrate C2 in a short time. This is preferable because damage to the substrate C2 can be reduced. On the other hand, if the diameter of the film forming roller is 1000 mmφ or less, it is preferable because the practicality can be maintained in the device design including the uniformity of the plasma discharge space.

In such a manufacturing apparatus C31, the resin substrate C2 is arranged on the pair of film forming rollers (film forming rollers C39 and C40) such 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 the discharge is generated in the facing space between the film-forming roller C39 and the film-forming roller C40 to generate plasma. It is possible to simultaneously form films on the respective surfaces of the substrate C2.

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 further the inorganic gas barrier layer component is 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 feed roller C32 and the transport rollers C33 to C36 used in such a manufacturing apparatus C31, known rollers can be appropriately used. Further, the winding roller C45 is not particularly limited as long as it can wind up the sealing substrate C1 in which the inorganic gas barrier layer C4 is formed on the resin substrate C2, 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 area; film formation zone) between the film formation roller C39 and the film formation roller C40. The pump is preferably provided in the other of the facing spaces. By disposing the gas supply pipe C41 which is the gas supply means and the vacuum pump which is the vacuum exhaustion means in this way, the film formation gas is efficiently supplied to the facing space between the film formation roller C39 and the film formation roller C40. And is excellent in that the film formation efficiency can be improved.

Further, as the plasma generation power source C42, a power source of a known plasma generator can be appropriately used. The plasma generating power source C42 as described above supplies electric power to the film forming roller C39 and the film forming roller C40 connected thereto, and makes it possible to use these as a counter electrode for discharging. As such a plasma generation power supply C42, a power supply capable of alternately reversing the polarities of the pair of film forming rollers (such as an AC power supply) because plasma CVD can be performed more efficiently. It is preferable to use.

Further, as the plasma generating power source C42, it is possible to more efficiently perform plasma CVD, so that the applied power can be within the range of 100 W to 10 kW and the frequency of the alternating current is 50 Hz. It is more preferable that the frequency can be set to ˜500 kHz.

Also, as the magnetic field generators C43 and C44, a known magnetic field generator can be appropriately used. Further, as the resin substrate C2, in addition to the resin substrate used in the present invention, a substrate on which an inorganic gas barrier layer C4 is previously formed can be used. As described above, by using the resin substrate C2 on which the inorganic gas barrier layer C4 is formed in advance, it is possible to increase the thickness of the inorganic gas barrier layer C4.

Using such a 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, using the manufacturing apparatus C31 shown in FIG. 41, while supplying a film forming gas (raw material gas or the like) into the vacuum chamber, a discharge is generated between the pair of film forming rollers C39 and C40, thereby forming the film forming gas. (Raw material gas and the like) is decomposed by the plasma, and the inorganic gas barrier layer C4 is formed by the plasma CVD method 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. It 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 axes of the film forming rollers C39 and C40, and the plasma is converged on the magnetic field. During such film formation, the resin substrate C2 is delivered by the delivery roller C32, the film formation roller C39, or the like, which enables a continuous film formation process of a roll-to-roll system, and The inorganic gas barrier layer C4 is formed on the surface.

As the film forming gas (raw material gas, etc.) 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 kinds. 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 source gas, for example, an organic silicon compound containing silicon or an organic compound gas containing carbon can be used. Examples of such an organosilicon compound include hexamethyldisiloxane (HMDSO), hexamethyldisilane (HMDS), 1,1,3,3-tetramethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, and hexamethyldisilane. , Methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane (TMOS), 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 viewpoints of handling properties of the compound and gas barrier properties of the obtained inorganic gas barrier layer C4. .. These organosilicon compounds may be used alone or in combination of two or more. In addition, examples of the carbon-containing organic compound gas include methane, ethane, ethylene, and acetylene. For these organic silicon compound gas and organic compound gas, appropriate source gases are 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 source gas. As such a reaction gas, a gas which 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 kinds. For example, when forming an oxynitride, for forming a reaction gas for forming an oxide and a nitride. Can be used in combination.

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 plasma discharge. As such carrier gas and discharge gas, known gases can be used as appropriate, and for example, rare gas such as helium, argon, neon, xenon, or hydrogen can be used.

When such a film-forming gas contains a source gas and a reaction gas, the ratio of the source gas and the reaction gas is the reaction theoretically required to completely react the source gas and the reaction gas. It is preferable not to make the ratio of the reaction gas too much over the ratio of the amount of gas. When the ratio of the reaction gas is not excessive, the formed inorganic gas barrier layer C4 is excellent in that excellent gas barrier properties and bending resistance can be obtained. Further, when the film forming gas contains an organosilicon compound and oxygen, it is preferably equal to or less than the theoretical oxygen amount necessary for completely oxidizing the total 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 source gas, as a film forming gas, Regarding the preferred ratio of the source gas to the reaction gas in the film forming gas, taking as an example the case of producing a silicon-oxygen thin film by using a gas containing oxygen (O ₂ ) as the reaction gas , Will be described in more detail.

A film formation gas containing hexamethyldisiloxane (HMDSO, (CH ₃ ) ₆ Si ₂ O) as a source gas and oxygen (O ₂ ) as a reaction gas is reacted by plasma CVD to produce a silicon-oxygen system. In the case of producing the thin film, the film forming gas causes a reaction represented by the following reaction formula (1) to generate silicon dioxide.

Reaction formula (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 moles or more of oxygen is contained in 1 mole of hexamethyldisiloxane in the deposition 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, a stoichiometric amount of oxygen is added to 1 mol of hexamethyldisiloxane so that the reaction of the reaction formula (1) does not proceed completely. It is preferable that the ratio is less than 12 mol.

In the actual reaction in the plasma CVD chamber, since hexamethyldisiloxane as a raw material and oxygen as a reaction gas are supplied to the film formation region from the gas supply unit to form a film, the molar amount of oxygen in the reaction gas is Even if the (flow rate) is 12 times the molar amount (flow rate) of the hexamethyldisiloxane as the raw material, the reaction cannot be completely progressed in reality and the oxygen content is It is considered that the reaction is completed only when a large excess is supplied compared to the stoichiometric ratio (for example, in order to completely oxidize by CVD to obtain silicon oxide, the molar amount of oxygen (flow rate) is set to hexamethyldiamine as a raw material). 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) which is a 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 taken into the inorganic gas barrier layer, and the resulting sealing substrate is It is possible to exhibit excellent gas barrier properties and flex resistance.

From the viewpoint of use as a flexible substrate for devices that require transparency, such as organic EL elements and solar cells, the molar amount of oxygen relative 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 of hexamethyldisiloxane (flow rate), and more preferably more than 0.5 times.

The pressure (vacuum degree) in the vacuum chamber can be appropriately adjusted according to the type of raw material gas, etc., but is preferably in the range of 0.5 to 50 Pa.

Further, in such a plasma CVD method, an electrode drum (installed on the film forming rollers C39 and C40) connected to a plasma generating power source C42 in order to discharge between the film forming roller C39 and the film forming roller C40. The electric power to be applied to the electric power source) can be appropriately adjusted according to the type of raw material gas, the pressure in the vacuum chamber, etc., but it cannot be said unequivocally, but it should be within the range of 0.1 to 10 kW. Is preferred. When the applied power is 0.1 kW or more, the generation of particles can be sufficiently suppressed, and when the applied power is 10 kW or less, the amount of heat generated during film formation can be suppressed and the film formation during film formation can be suppressed. It is possible to prevent the temperature of the surface of the resin substrate from rising. 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 the source gas, the pressure in the vacuum chamber, etc., but is preferably in the range of 0.25 to 100 m/min, More preferably, it is within 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 on the resin substrate due to heat. On the other hand, when it is 100 m/min or less, it is excellent in that a layer thickness sufficient as an inorganic gas barrier layer can be secured without impairing productivity.

As described above, in a more preferable aspect of the present embodiment, the inorganic gas barrier layer used in the present invention is a 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 it is mass-produced by using a plasma CVD device (roll-to-roll method) having a facing roller electrode, and has mechanical strength, particularly, roll-to-roll transfer. This is because it is possible to efficiently produce an inorganic gas barrier layer that has both durability at time and gas barrier performance. Such a manufacturing apparatus is also excellent in that it is possible to mass-produce the sealing substrate, which is used in a solar cell, an electronic component, and the like, and which is required to have durability against temperature changes, at low cost and easily.

Next, the inorganic gas barrier layer formed by modifying 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, such as SiO ₂ , Si ₃ N having a bond such as Si—N, Si—H, N—H. ₄ , and both intermediate solid solutions are ceramic precursor inorganic polymers such as SiO _x N _y , and preferably have a structure represented by the following general formula (P).

General formula (P)
-[-Si(R ₁ )(R ₂ )-N(R ₃ )-] _n-
In formula (P), R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group or an alkoxy group. R ₁ , R ₂ and R ₃ may be the same or different from each other.

In the general formula (P), n is an integer, and it is preferable that the polysilazane having the structure represented by the general formula (P) is determined so as 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 resulting inorganic gas barrier layer as a film.

It is estimated that perhydropolysilazane has a linear structure and a ring structure centered on a 6- or 8-membered ring. Its molecular weight is about 600 to 2000 (in terms of polystyrene) in terms of number average molecular weight (Mn), it is a liquid or solid substance, and it varies depending on the molecular weight.

Polysilazane is marketed as a solution dissolved in an organic solvent, and a commercially available product can be used as it is as a coating solution for forming a polysilazane layer. Commercial products of the polysilazane solution include NN120-10, NN120-20, NAX120-20, NN110, NN310, NN320, NL110A, NL120A, NL120-20, NL150A, NP110, NP140, SP140 and the like manufactured by AZ Electronic Materials Co., Ltd. Are listed.

The solvent for preparing a coating solution containing polysilazane (hereinafter also simply referred to as a polysilazane-containing coating solution) is not particularly limited as long as it can dissolve polysilazane, but water and water which easily react with polysilazane An organic solvent that does not contain a reactive group (for example, a hydroxy group, an amine group, or the like) and is inert to polysilazane is preferable, and an aprotic organic solvent is more preferable.

Specifically, as the solvent for preparing the polysilazane-containing coating solution, an aprotic solvent, for example, pentane, hexane, cyclohexane, toluene, xylene, sorbesso, aliphatic hydrocarbons such as turbene, alicyclic hydrocarbons , Hydrocarbon solvents such as aromatic hydrocarbons, halogenated hydrocarbon solvents such as methylene chloride and trichloroethane, esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, aliphatic compounds such as dibutyl ether, dioxane and tetrahydrofuran Ethers such as ethers and alicyclic ethers (eg, tetrahydrofuran, dibutyl ether, mono- and polyalkylene glycol dialkyl ethers (diglymes)) and the like can be mentioned. The above-mentioned solvent is selected depending on 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 the polysilazane in the polysilazane-containing coating solution is not particularly limited and varies depending on the layer thickness of the desired inorganic gas barrier layer and the pot life of the coating solution, but is preferably within the range of 0.1 to 30 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 accelerate the modification into silicon oxynitride. The catalyst applicable to the present invention is preferably a basic catalyst, and particularly 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 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, further preferably 0.5, based on polysilazane. It is in the range of up to 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, decrease in film density, increase in film defects, and the like.

The following additives 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, polymerized resins, etc.), condensation Resins (for example, aminoplast, particularly urea resin, melamine formaldehyde resin, alkyd resin, acrylic resin, polyester or modified polyester, epoxide, polyisocyanate or blocked polyisocyanate, polysiloxane, etc.).

As a method of 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 casting film forming method, a bar coating method, and a gravure printing method. To be

The coating thickness can be set appropriately according to the purpose. For example, the coating thickness after drying is preferably about 10 nm to 10 μm, more preferably 15 nm to 1 μm, and further preferably 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 coating properties can be obtained when forming the polysilazane layer and high light transmittance can be realized. ..

“Reforming treatment” means a reaction in which a part or all of a polysilazane compound is converted into silicon oxide or silicon oxynitride.

As a result, it is possible to form an inorganic thin film at a level at which the inorganic gas barrier layer can contribute to exhibiting a gas barrier property (water vapor permeability of 1×10 ⁻³ g/(m ² ·day) or less) as a whole.

Specifically, heat treatment, plasma treatment, active energy ray irradiation treatment, etc. can be mentioned. Among them, the treatment by irradiation with active energy rays is preferable from the viewpoint of being capable of being reformed at a low temperature and having a high degree of freedom in selecting the type of base material.

(Heat treatment)
As the method of heat treatment, for example, a method of heating the coating film by heat conduction by contacting the substrate with a heating element such as a heat block, a method of heating the environment in which the coating film is placed by an external heater such as a resistance wire, Examples thereof include a method using light in the infrared region such as an IR heater, but are not limited thereto. When performing the heat treatment, 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, more preferably 30 seconds to 5 minutes.

(Plasma treatment)
In the present invention, as the plasma treatment that can be used as the modifying treatment, a known method can be used, but preferably atmospheric pressure plasma treatment or the like can be mentioned. Compared with the plasma CVD method under vacuum, the atmospheric pressure plasma CVD method, which performs plasma CVD processing in the vicinity of atmospheric pressure, does not need to be decompressed and has high productivity. Since the mean free path of the gas is very short under a high pressure condition of atmospheric pressure as compared with the conditions of the usual CVD method, the film is extremely homogeneous as compared with the conditions of the ordinary CVD method.

In the case of atmospheric pressure plasma treatment, nitrogen gas or a Group 18 atom of the long periodic table, specifically, helium, neon, argon, krypton, xenon, radon, etc., 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 ray, 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 rays 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 a high oxidizing ability, and can form a gas barrier layer having a high density and an insulating property at a low temperature.

In the ultraviolet irradiation treatment, it is possible to use any of the commonly used ultraviolet ray generators.

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 a treatment by irradiation with ultraviolet light. Ozone and active oxygen atoms generated by ultraviolet rays have a high oxidizing ability, and it is possible to form a silicon oxide film or a silicon oxynitride film having a high density and an insulating property at a low temperature.

By this ultraviolet light irradiation, O ₂ and H ₂ O that contribute to ceramization, the ultraviolet absorber, and polysilazane itself are excited and activated. Then, the excited polysilazane is promoted to be ceramic, and the obtained ceramic film becomes dense. Irradiation with ultraviolet light is effective at any time after the coating film is formed.

For the vacuum ultraviolet light irradiation treatment in the present invention, any commonly used ultraviolet ray generator can be used. The ultraviolet light referred to in the present invention is generally referred to as vacuum ultraviolet light, which is ultraviolet light containing electromagnetic waves having a wavelength of 10 to 200 nm.

It is preferable to set the irradiation intensity and irradiation time of the vacuum ultraviolet light irradiation within a range in which the resin substrate supporting the layer containing the polysilazane compound before modification is not damaged.

For example, a 2 kW (80 W/cm×25 cm) lamp is used, and 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 , and the base material-ultraviolet rays. By setting the distance between the irradiation lamps, irradiation can be performed for 0.1 seconds to 10 minutes.

In general, when the temperature of the support during the UV irradiation treatment is 150° C. or higher, in the case of a resin film or the like, the properties of the support may be impaired such as the support being deformed or its strength being deteriorated. Become. However, in the case of a film having a high heat resistance such as an acrylic resin, 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 this ultraviolet irradiation, and those skilled in the art can set it appropriately depending on the type of the resin substrate. Further, the ultraviolet irradiation atmosphere is not particularly limited and may be carried out in the air.

Examples of such ultraviolet ray generating means 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, and UV light lasers. Further, when irradiating the polysilazane layer before modification with the generated ultraviolet rays, from the viewpoint of achieving efficiency improvement and uniform irradiation, the polysilazane before modification after reflecting the ultraviolet rays from the generation source with a reflecting plate. It is desirable to irradiate the layer.

UV irradiation can be applied to both batch processing and continuous processing, and can be appropriately selected according to the shape of the resin substrate used. When the resin substrate having a coating layer containing a polysilazane compound is in the form of a long film, it is made into ceramics by continuously irradiating it with ultraviolet rays in a drying zone equipped with the above-mentioned ultraviolet ray source while transporting the resin substrate. can do. The time required for UV irradiation depends on the composition and concentration of the resin substrate used and the coating layer containing the polysilazane compound, but it is generally 0.1 second to 10 minutes, preferably 0.5 second 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 vacuum ultraviolet light (VUV) irradiation is performed, it is preferable to use a dry inert gas as a gas other than oxygen, and it is particularly preferable to use dry nitrogen gas from the viewpoint of cost. The oxygen concentration can be adjusted by measuring the flow rates of oxygen gas and inert gas introduced into the irradiation chamber and changing the flow rate ratio.

Specifically, the method of modifying the layer containing the polysilazane compound before modification in the present invention is a treatment by vacuum ultraviolet light irradiation. 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 bonding of atoms is called a photon process called a photon process. This is a method of forming a silicon oxide film at a relatively low temperature by advancing an oxidation reaction by active oxygen or ozone while directly cutting by the action of only. A rare gas excimer lamp is preferably used as the vacuum ultraviolet light source required for this.

Note that atoms of a rare gas such as Xe, Kr, Ar, and Ne do not chemically bond to form a molecule, and are called inert gases. However, the atoms of the rare gas (excited atoms) that have gained energy by discharge or the like can combine with other atoms to form molecules. If the noble gas is xenon,
e+Xe→e+Xe ^*
Xe ^* +Xe+Xe→Xe ₂ ^* +Xe
Xe ₂ ^* →Xe+Xe+hν (172 nm)
Then, when the excited excimer molecule Xe ₂ ^* transits to the ground state, it emits excimer light (vacuum ultraviolet light) of 172 nm.

　The characteristic of the excimer lamp is that the radiation is concentrated in one wavelength and almost no radiation other than the necessary light is emitted, resulting in high efficiency. Moreover, since the excess 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/blink instantaneously.

In the vacuum ultraviolet ray irradiation step, the illuminance of vacuum ultraviolet rays on the surface of the coating film which the coating film containing the polysilazane compound receives is preferably in the range of 1 mW/cm ² to 10 W/cm ² , and in the range of 30 to 200 mW/cm ² . Is more preferable, 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, if it is 10 W/cm ² or less, abrasion of the coating film is unlikely to occur and the resin substrate is less likely to be damaged.

The irradiation energy of vacuum ultraviolet rays in the layer containing the polysilazane compound is preferably in the range of 10 to 10000 mJ/cm ² , more preferably in the range of 100 to 8000 mJ/cm ² , and more preferably 200 to 6000 mJ/cm ² . More preferably, it is particularly preferably 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.

The oxygen concentration during irradiation with vacuum ultraviolet light (VUV) is preferably in the range of 300 to 10000 volume ppm (1 volume %), and more preferably 500 to 5000 volume ppm. By adjusting the oxygen concentration within such a range, it is possible to prevent the formation of an excessive oxygen-containing inorganic gas barrier layer and prevent the deterioration of the gas barrier property.

A method using dielectric barrier discharge is known to obtain excimer light emission. Dielectric barrier discharge is a lightning generated in a gas space by arranging a gas space between both electrodes via a dielectric (transparent quartz in the case of an excimer lamp) and applying a high frequency high voltage of several 10 kHz to the electrodes. It is a very similar micro discharge called discharge.

In addition to the dielectric barrier discharge, electrodeless electric field discharge is also known as a method of efficiently obtaining excimer light emission. Electrodeless electric field discharge is discharge by capacitive coupling, and is also called RF discharge. The lamp, the electrode, and the arrangement thereof may be basically the same as the dielectric barrier discharge, but the high frequency applied between both electrodes is turned on at several MHz. In this manner, the electrodeless electric field discharge can obtain a uniform discharge spatially and temporally.

The Xe excimer lamp has excellent emission efficiency because it emits a short wavelength of 172 nm ultraviolet light at a single wavelength. Since this light has a large absorption coefficient of oxygen, it is possible to generate radical oxygen atomic species and ozone at a high concentration with a small amount of oxygen. Further, it is known that the energy of light having a short wavelength of 172 nm that dissociates the bond of an organic substance is high. Due to the high energy of the active oxygen and ozone and the ultraviolet radiation, the coating layer containing the polysilazane compound can be modified in a short time. Therefore, compared with low-pressure mercury lamps with wavelengths of 185 nm and 254 nm and plasma cleaning, process time is shortened due to high throughput, equipment area is reduced, and irradiation of organic materials, plastic substrates, resin films, etc., which are easily damaged by heat, is performed. It is possible.

Also, since the excimer lamp has a high light generation efficiency, it can be turned on with low power input. In addition, since light with 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 irradiation target is suppressed from rising. Therefore, it is suitable for irradiation of a sealing substrate having a base material of a resin film such as polyethylene terephthalate, which is considered to be easily affected by heat.

The layer formed by the above coating has a composition of SiO _x N _y C _z as a whole layer by modifying at least a part of polysilazane in the step of irradiating a coating film containing a polysilazane compound with vacuum ultraviolet rays. A silicon-containing film containing the indicated silicon oxynitride is formed.

The film 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 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 can be improved to prevent deterioration of the gas barrier property and deterioration of the film under high temperature and high humidity conditions.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, “parts” or “%” is used, but unless otherwise specified, “parts by mass” or “% by mass” is shown.

[Example 1]
<Preparation of rubber particles B-1>
Into a reactor with a reflux condenser having an internal volume of 60 liters, 38.2 liters of ion-exchanged water and 111.6 g of sodium dioctylsulfosuccinate were charged, and the temperature was raised to 75° C. under a nitrogen atmosphere while stirring at a rotation speed of 250 rpm. , So that the effect of oxygen is virtually eliminated. 0.36 g of ammonium persulfate (APS) was added, and after stirring for 5 minutes, 1657 g of methyl methacrylate (MMA), 21.6 g of butyl acrylate (BA), and 1.68 g of allyl methacrylate (ALMA) (c1). ) Was added all at once, and after the exothermic peak was detected, it was held for another 20 minutes to complete the polymerization of the innermost hard layer.

Next, 3.48 g of ammonium persulfate (APS) was charged, and after stirring for 5 minutes, 1961 g of butyl acrylate (BA), 346 g of methyl methacrylate (MMA), and 264.0 g of allyl methacrylate (ALMA) (a monomer mixture ( a1) (BA/MMA=85/15 mass ratio) was continuously added over 120 minutes, and after the addition was completed, the mixture was kept for another 120 minutes 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. After completion of the addition, the polymerization was continued for 20 minutes to complete the polymerization of the hard layer 1.

Next, 1.32 g of ammonium persulfate (APS) was added, and after 5 minutes, 3148 g of methyl methacrylate (MMA), 201.6 g of butyl acrylate (BA), and 10.1 g of n-octyl mercaptan (n-OM) were added. The monomer mixture (b2) was continuously added over 20 minutes, and the addition was continued for 20 minutes after the addition was completed. Then, the temperature was raised to 95° C. and kept for 60 minutes to complete the polymerization of the hard layer 2.

A small amount of the obtained polymer latex was sampled, and the average particle size was determined by the absorbance method. The average particle size was 0.10 μm. The remaining latex was put into a 3% by mass aqueous solution of sodium sulfate, salted out and coagulated, and then dehydration/washing was repeated, followed by drying, and 4-layer structure acrylic particles (rubber particles B-1). Got The obtained rubber particles B-1 had an average particle diameter of 200 nm and a glass transition temperature (Tg) of -30°C.

<Production 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 were mixed by stirring with a dissolver for 50 minutes, and then dispersed under a 1500 rpm condition using a Milder disperser (manufactured by Taiheiyo Kiko Co., Ltd.). Then, a rubber particle dispersion liquid was obtained. After that, the rubber particle dispersion was stagnated in the storage tank for 6 hours, and was constantly stirred during storage.

(Preparation of dope)
Then, a dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Next, the acrylic resin (A-1) shown in Table II below was put into the pressure dissolution tank while stirring. Next, the above-prepared rubber particle dispersion liquid was added, and this was heated to 60° C. and completely dissolved while stirring. The heating temperature was increased from room temperature at 5°C/min, dissolved in 30 minutes, and then lowered at 3°C/min. The obtained solution was filtered with a filter having a filtration accuracy of 30 μm to obtain a dope.

(Dope composition)
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 casting device, the dope was uniformly cast on a stainless belt support at a temperature of 31° C. and a width of 1800 mm. The temperature of the stainless belt was controlled at 28°C. The transport speed of the stainless belt was 20 m/min.

On a stainless belt support, the solvent was evaporated until the residual solvent amount in the cast film was 30%. Then, it was peeled from the stainless belt support with a peeling tension of 128 N/m. While the peeled film was conveyed by a large number of rollers, the obtained film-like product was stretched 1.2 times in the width direction with a tenter at (Tg+10)° C. (120° C. in this example). Then, it was further dried while being conveyed by a roll, and the end portion sandwiched by 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.

<Production 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 Tables II and III were changed.

<Evaluation of optical film>
The following measurements and evaluations were performed on the optical films 101 to 112.
<Transparency>
It was measured using an image clarity measuring device ICM-1T manufactured by Suga Test Instruments Co., Ltd. The transmission measurement, which is normally performed at an incident angle of 0 degree, was performed as a transmission measurement at an incident angle of 75 degrees. The sample was set so that the flow direction of the film and the direction of the optical comb tooth were parallel. The width (pitch) of the optical comb teeth was 0.125 mm.
In addition, by moving the optical comb orthogonal to the optical axis of the transmitted light of the test piece, the light amount (M) when the comb transmitting portion is on the optical axis and the light amount (m) when the comb light shielding portion is present on the optical axis are obtained. The ratio (C value (%)) of the difference (M−m) between the two and the sum (M+m) is a measure of the image definition.
The C value is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more.

<Measurement of the number of foreign substances>
The film was placed on a horizontal table, the light of a fluorescent lamp was reflected, and foreign matter was visually observed.
◯: The number of foreign matters is 3/m ² or less.
Δ: The number of foreign matters is more than 3/m ² and 6/m ² or less.
X: The number of foreign matters is more than 6/m ² .

<Bendability>
The frequency at which the obtained optical film was broken when folded in two was evaluated. ○ and △ are set to levels at which there is no practical problem.
◯: Does not break at all Δ: May break once every several times ×: Always breaks

The production requirements and evaluation results of the acrylic resin film described above are summarized in Tables II and III.

As is clear from the results shown in Table III, it is clear that the acrylic resin film produced by the production method of the present invention has excellent transmission imageability, has few foreign matters, and is excellent in bendability.

[Example 2]
<Preparation of organic matting agent 1>
(Preparation of seed particles)
A polymerization vessel equipped with a stirrer and a thermometer was charged with 1000 g of deionized water, charged with 50 g of methyl methacrylate and 6 g of t-dodecyl mercaptan, and heated to 70° C. under nitrogen with 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 polymerization was carried out for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

(Preparation of polymer particles)
A polymerization vessel equipped with a stirrer and a thermometer was charged with 800 g of deionized water in which 2.4 g of sodium lauryl sulfate was dissolved as a gelation inhibitor, and 66 g of methyl methacrylate, 20 g of styrene and ethylene glycol were added as a monomer mixture. A mixed solution of 64 g of dimethacrylate and 1 g of azobisisobutyronitrile as a polymerization initiator was added. Then, the mixed solution was mixed with T. The dispersion was obtained by stirring with a K homomixer (made by Tokushu Kika Kogyo Co., Ltd.).

To the obtained dispersion liquid, 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. Then, the absorbed monomer mixture is heated under a nitrogen stream at 50° C. for 5 hours for polymerization, and then cooled to room temperature (about 25° C.) to obtain polymer fine particles 1 (organic fine particles 1). A slurry of Complex 1 containing sodium laurate (gelling inhibitor) attached to its surface 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 system, 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 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 the organic matting agent 1 and 400 parts by mass of methylene chloride were mixed by stirring with a dissolver for 50 minutes, and then dispersed under a 1500 rpm condition using a Milder disperser (manufactured by Taiheiyo Kiko Co., Ltd.). Thus, an organic matting agent dispersion liquid was obtained.

<Production of optical film 201>
A dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Next, the acrylic resin (A-1) was put into the pressure dissolution tank while stirring. Next, the above-prepared rubber particle dispersion liquid and an organic matting agent dispersion liquid containing the following exemplary compound 176 as an additive 1 and the organic matting agent 1 as an additive 3 are charged and heated to 60° C., It was completely dissolved with stirring. The heating temperature was increased from room temperature at 5°C/min, dissolved in 30 minutes, and then lowered at 3°C/min. The obtained solution was filtered with a filter having a filtration accuracy of 30 μm to obtain a dope.

(Dope composition)
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, an optical film 201 having a thickness of 40 μm was obtained using the obtained dope in the same manner as the film formation in the production of the optical film 101.

<Production of optical films 202 to 211>
Optical films 202 to 211 were prepared in the same manner as in the production of the optical film 201 except that the types and amounts of the additives 1 to 3 were changed as shown in Table IV below.

Note that each compound shown in Table IV is as follows.

RZ-2: C ₁₂ H ₂₅ O-P(=O)-(OK) ₂
RZ-10: C ₁₂ H ₂₅ OSO ₃ Na

<Evaluation of concave deformation>
Among the obtained film surfaces, the surface in contact with the metal belt was observed in 20 fields of view with a laser microscope field of view of 2 mm×2.7 mm, and the number of concave shapes of 10 μm or more was counted. ○ and △ are set to levels at which there is no practical problem.
○: 0 to 1 △: 2 to 5 ×: 6 or more

<Evaluation of storability>
The film was cut into a 1 cm square, a 5 mm cut was made with a razor in parallel with the tenter stretching direction, and the glass plate was pasted with a double-sided tape. The film together with the glass plate was stored in a constant temperature bath under the conditions of cycle of 60° C. 90% RH and 20° C. 90% RH for 2 hours. After 100 cycles, the cut state was observed under a microscope. ○ and △ are set to levels at which there is no practical problem. ◯: No change Δ: Incision progressed in a range of less than 1 mm ×: Incision progressed 1 mm or more, or a crack was generated in a direction different from the incision

[Example 3]
<Production of optical films 301 to 303>
In the preparation of the rubber particle dispersion in the production of the optical film 101, “prescription of dispersion (rubber particles, addition amount of methylene chloride and presence/absence of methanol)”, “mixing/dispersing machine and its conditions”, Optical films 301 to 303 were produced in the same manner except that "storage/addition and conditions thereof" 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 (retardation film) and sandwiching it with two glass plates having a thickness of 1.3 mm (MICRO SLIDE GLASS product number S9213, manufactured by MATSUNAMI) from both sides. The value (%) obtained by subtracting the haze measured with a few drops of glycerin dropped between two glass plates 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 uniform dry air was blown to the wet casting film immediately after casting.
The wind speed at the belt was adjusted to be Table VI. Further, the casting film at the place 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 deviation in the width direction was measured by scanning with a laser film thickness meter at a pitch of 0.5 mm and a width of 500 mm. 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 with each other.

As can be seen from Table VI above, by controlling the wind speed to 0.2 m/sec or less, the film thickness fluctuation in the 30 to 50 mm cycle was significantly suppressed.

[Example 5] IR heater (full width)
During the production of the optical film 101, the IR heater was irradiated over the entire width at the stage of peeling from the stainless belt support. After the irradiation, an optical film 501 was prepared through a tenter like the optical film 101.
As the IR heater, a line-focusing type, water-cooling type, and mid-infrared radiation type (energy density 7 W/mm, focal length 20 mm, emission wavelength approximately 1 to 10 μm) manufactured by Hibeck Co. was selected. The irradiation surface of the film was 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 obtained optical films 501 and 101 was measured. It was confirmed that the optical film 501 had less curl and less edge at the edge of the film. Further, the solvent (methylene chloride and ethanol) contained in each film was quantified immediately before the introduction of the tenter during the production to calculate the residual rate.

<Measuring method of curl value>
From the created optical film, cut out squares of 4 cm square parallel to the MD and TD directions, adjust the humidity overnight in an environment of 23°C and 20%, and stand up at four corners when placed flat on a horizontal desk. Was averaged to obtain a curl value.
<Scratch evaluation method>
The produced 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 observing under a fluorescent lamp.
Solvent residual rate (%)=mass of quantified solvent/mass of absolutely dried film×100
The film was dried at 120° C. for 60 minutes.

[Example 6] IR heater (only at the end)
During the production of the optical film 101, at the stage of peeling from the stainless belt support, the IR heater was irradiated only to the width of 50 mm at both ends of the film. The irradiation conditions were the same as 101. After the irradiation, an optical film 601 was prepared through a tenter in the same manner as 101.
With the obtained optical films 601 and 101, the film thickness deviation in the width direction was measured.

<Method of measuring film thickness deviation>
The film width was divided into 10 parts, the film thickness was measured in the vicinity of the center of each section, and the standard deviation value of 10-point data was taken as the film thickness deviation.

[Example 7]
The

optical films

101, 106, 107, 110 to 112 of the present invention produced in Example 1 were used as the base film (support) of the gas barrier film.

<Production of gas barrier film 1001>
(Support)
As the resin film support, the optical film (acrylic resin film) 101 manufactured in Example 1 was used.

The gas barrier film was produced by transporting the support at a speed of 20 m/min, forming a bleed-out prevention layer on one side and a smooth layer on the opposite side by the following forming method, and then applying an adhesive protective film. A bonded roll-shaped gas barrier film was obtained.

(Formation of bleed-out prevention layer)
UV curable organic/inorganic hybrid hard coat material OPSTAR Z7535 manufactured by JSR Corporation is applied to one surface of the support, and a wire bar is applied so that the film thickness after drying 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)
Then, on the opposite surface of the support, UV curing type organic/inorganic hybrid hard coat material OPSTAR Z7501 manufactured by JSR Co., Ltd. was applied and then applied with a wire bar so that the film thickness after drying was 4 μm, and then at 80° C. After drying for 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 sectional height Rt(p) at this time was 18 nm. The maximum cross-section height Rt(p) is calculated from the cross-sectional curve of the unevenness continuously measured by a detector having a probe with a minimum tip radius with an AFM (atomic force microscope). This is the average roughness of the amplitude of the fine irregularities, which was measured many times in the section where the measurement direction was 30 μm.

(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, and the temperature was adjusted to 23° C. and 50% RH environment. After coating below, it was dried at 80° C. for 1 minute (the atmosphere in 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, AZ Electronic Materials Co., Ltd., 20 mass% dibutyl ether solution)
(Reforming treatment A)
The coating sample was subjected to a modification treatment under the following conditions to form a first gas barrier layer. The dew point temperature during the modification treatment was -8°C.

(Reformer)
Eximer irradiation device MODEL: MECL-M-1-200, wavelength 172 nm, lamp-filled gas manufactured by M.D.COM Co., Ltd. A sample fixed on the Xe operating stage was subjected to a modification treatment under the following conditions.

(Reforming treatment conditions)
Excimer light intensity 120 mW/cm ² (172 nm)
Distance between sample and light source 3 mm
Stage heating temperature 25℃
Oxygen concentration in irradiation device 1000ppm (0.1%)
Actual excimer irradiation time: 5 seconds Further, the concentration of the polysilazane compound coating solution was adjusted by diluting the polysilazane compound coating solution with dehydrated dibutyl ether, followed by coating in an environment of 23° C. and 50% RH, and then at 80° C. for 1 minute (in the process The atmosphere was adjusted to a dew point temperature of 10° C.) and dried to form a polysilazane layer so that the film thickness after drying was 90 nm.

(Reforming treatment B)
The sample coated with the second coating layer was subjected to a modification treatment at an integrated light amount of 500 mJ/cm ² and a stage heating temperature (substrate temperature during VUV irradiation) of 25° C. to form a second gas barrier layer. The dew point temperature during the modification treatment was -8° C. to obtain a gas barrier film 1001.

(Reformer)
Same as modification treatment A.

(Reforming treatment conditions)
Excimer light intensity 120 mW/cm ² (172 nm)
Distance between sample and light source 3 mm
Oxygen concentration in irradiation device 1000ppm (0.1%)
Stage movement speed 10 mm/sec. Reciprocating sample

<Preparation of Gas Barrier Films 1002 to 1006>
Gas barrier films 1002 to 1006 were produced in the same manner as in the production of the gas barrier films 1001 except that the supports were changed to the

optical films

106, 107 and 110 to 112, respectively.

<<Evaluation of gas barrier film>>
(Measurement of water vapor transmission rate)
<Measurement device for water vapor transmission rate>
Vapor deposition equipment: JEOL vacuum deposition equipment JEE-400
Constant temperature and constant humidity oven: Yamato Humidic Chamber IG47M
(raw materials)
Metals that react with water and corrode: 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 (JEE-400 vacuum vapor deposition device manufactured by JEOL Ltd.), mask the gas barrier films 1001 to 1006 before attaching the transparent conductive film, except for the portions to be vapor deposited (12 mm x 12 mm at 9 locations). , Metal calcium was deposited.
Then, the mask was removed in a vacuum state, and aluminum was vapor-deposited from another metal vapor deposition source on the entire surface of one side of the sheet. After sealing with aluminum, the vacuum state is released, and immediately in a dry nitrogen gas atmosphere, quartz glass with a thickness of 0.2 mm is faced to the aluminum-sealed side via a sealing UV-curable resin (made by Nagase Chemtex). Then, the evaluation cell was produced by irradiating with ultraviolet rays.
The obtained sealed sample on both sides was stored under a high temperature and high humidity condition of 60° C. and 90% RH, and based on the method described in JP-A-2005-283561, moisture permeated into the cell from the corrosive amount of metallic calcium. The amount was calculated.

(Rank evaluation)
5:1×10 ⁻⁴ g/m ² /day or less 4:1×10 ⁻⁴ g/m ² /day or more, 1×10 ⁻³ g/m ² /day or less 3:1×10 ⁻³ g/ m ² /day or more and less than 1×10 ⁻² g/m ² /day 2:1×10 ⁻² g/m ² /day or more, less than 1×10 ⁻¹ g/m ² /day 1:1×10 ⁻¹ g/m ² /day or higher In the rank evaluation, the practical range is rank 3 or higher.

(Heat resistance test of gas barrier film)
Immediately after production, the gas barrier films 1001 to 1006 were stored in an environment of 85° C. for 7 days, and the water vapor transmission rate was measured in the same manner as above to evaluate deterioration by heat (durability).

(Durability test of gas barrier film)
The deterioration (durability) of the gas barrier property after repeating 100 times bending of the gas barrier films 1001 to 1006 immediately after production at an angle of 180 degrees so as to have a radius of curvature of 10 mm is the same as above. The water vapor transmission rate was evaluated.
As a result of the above evaluations, it was confirmed that the optical film of the present invention has a rank of 3 or higher for all evaluation items and is a support for an excellent gas barrier film.

[Example 8]
The

optical films

101, 106, 107, 110 to 112 of the present invention produced in Example 1 were used as a base film (support) for a touch panel.

(Preparation of transparent substrate)
The following coating solution for hard coat layer was applied to both surfaces of the

optical films

101, 106, 107, 110 to 112 by a die coater to form a coating film to be a hard coat layer. The coating film was dried at 70° C., and while purging with nitrogen so that the oxygen concentration was 1.0 vol% or less, an ultraviolet lamp was used and the illuminance of the irradiation part 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-treatment zone to produce transparent substrates 1101 to 1106. The thickness of the hard coat layer after curing was 5 μm.

(Preparation of coating liquid for hard coat layer)
The following constituent materials were 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 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 0.47-0) .61 μm, manufactured by Nippon Shokubai 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

(Preparation of conductive film 1101)
On one surface of the transparent substrate 1101, an intermediate layer (film thickness 25 nm) was formed by using the following compound 1 by a vapor deposition method, and subsequently an electrode layer (film thickness 8 nm) made of silver (Ag) was formed by a vapor deposition method. did. Further subsequently, a surface protective layer (thickness 30 nm) made of titanium oxide (TiO ₂ ) was formed by vapor deposition. Thus, a conductive film 1101 having a transparent electrode having a three-layer structure including the intermediate layer, the transparent conductive layer, and the surface protective layer was produced.

At this time, first, the transparent substrate 1101 was fixed to a base material holder of a commercially available vacuum vapor deposition device. Further, the above compound 1 was put in a tantalum resistance heating boat. These substrate holder and heating boat were attached to the first vacuum tank of the vacuum vapor deposition apparatus. Further, silver (Ag) was put into a resistance heating boat made of tungsten, and the boat was mounted in the second vacuum tank. Further, titanium oxide (TiO ₂ ) was put into a resistance heating boat made of tantalum and mounted in the third vacuum tank.

Next, after depressurizing the first vacuum chamber to 4×10 ⁻⁴ Pa, electricity is applied to the heating boat containing each compound to heat it, and the transparent substrate 1101 is vapor-deposited at a deposition rate of 0.1 to 0.2 nm/sec. An intermediate layer having a film thickness of 25 nm was provided.

Next, the transparent substrate 1101 on which the intermediate layer is formed is transferred to a second vacuum tank while keeping the vacuum, the pressure in the second vacuum tank is reduced to 4×10 ⁻⁴ Pa, and then a heating boat containing silver is energized and heated. did. Thus, a transparent conductive layer made of silver and 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 are formed is transferred to a third vacuum tank while keeping the vacuum, the pressure in the third vacuum tank is reduced to 4×10 ⁻⁴ Pa, and then titanium oxide (TiO ₂ ) is 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 above this, and a surface protective layer was obtained.

Note that the vapor deposition film thickness is J. A. Woollam Co. Inc. VB-250 type VASE ellipsometer manufactured by K.K.

(Production of Conductive Films 1102-1106)
In the same manner as the conductive film 1101, the conductive films 1102 to 1106 were produced by using the

optical films

106, 107 and 110 to 112, respectively.

<<Evaluation of each sample>>
With respect to the produced conductive films 1101 to 1106, flex resistance, unevenness of interference, and deterioration in specific resistance after wet heat durability were measured.

(Flex resistance)
The bending resistance of the produced conductive film was evaluated according to the method specified in JIS K5400. A stainless rod having a diameter of 10 mm was used for winding the conductive film sample for the evaluation of flex resistance.
The rank of the electrode layer was evaluated as follows.
⊚: No change ○: Slightly deformed, but practically no problem △: Microcracks in electrode layer ×: Cracks in electrode layer

(Color unevenness)
The touch panel of the iPad (registered trademark) (a 9.7-inch IPS liquid crystal tablet computer made by Apple Inc.) was removed, and the produced conductive film was put through a 25 μm double-sided adhesive tape (Lintec substrateless tape MO-3005C). , And the conductive layer was attached so that the conductive layer faced 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, rank evaluation was performed as follows.
⊚: No color unevenness was observed at all ◯: Slight color unevenness was observed, but there was no problem in practical use Δ: Color unevenness was observed ×: Very dark rainbow-like color unevenness was observed

(Surface resistance deterioration due to wet heat durability)
After leaving the sample whose surface resistivity was measured for 300 hours in an environment of a temperature of 60° C. and a relative humidity of 90% RH, surface specific resistance values at arbitrary 10 points were measured, and an average value was measured after the sample was subjected to wet heat durability. The surface resistivity was used.
As a result of the test, rank evaluation was performed as follows.
When [surface resistance deterioration]=[(surface resistance after wet heat durability)-(surface resistance before wet heat durability)]/[surface resistance before wet heat durability],
⊚: Surface resistance deterioration is less than ±10% ○: Surface resistance deterioration is ±10% or more and less than ±20% △: Surface resistance deterioration is ±20% or more and less than ±30% × : Deterioration of surface resistance is ±30%. When the above evaluations were carried out, all evaluations using the optical film of the present invention were ◯ or more, and a support of an excellent conductive film for a touch panel. Was confirmed.

[Example 9]
Each of the

optical films

101, 106, 107, and 110 to 112 of the present invention produced in Example 1 was used as a substrate film (support) for a flexible organic electroluminescence element.

Transparent conductive films 1201 to 1206 were produced by forming thin films of clear hard coat layer (both sides), moisture-proof film (both sides) and transparent conductive film (one side) on the above film in this order.

<Preparation of clear hard coat layer>
The following hard coat layer coating composition was coated on the optical film 101 with an extrusion coater so that the film thickness was 3 μm, and then dried for 1 minute in a drying section set at 80° C., and then irradiated with ultraviolet rays at 120 mW/cm ^2. It was formed by doing.

(Clear hard coat layer coating composition)
Dipentaerythritol hexaatalylate monomer: 60 parts by mass Dipentaerythritol hexaatalylate dimer: 20 parts by mass Dipentaerythritol hexaatalylate trimer or more components: 20 parts by mass Dimethoxybenzophenone: 4 parts by mass Ethyl acetate: 50 parts by mass Ethynoleethyl ketone: 50 parts by mass Isopropyl alcohol: 50 parts by mass

<Preparation of moisture-proof film>
As a 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 materials were used as the electrodes. A 200 mm x 200 mm x 2 mm stainless steel plate was coated with a high-density, highly-adhesive alumina sprayed film, and then a solution of tetramethoxysilane diluted with ethyl acetate was applied and dried, and then cured by ultraviolet irradiation to perform sealing treatment. Further, the dielectric surface coated in this way was polished, smoothed, and processed to have a surface roughness Ra of 5 μm. The electrode was prepared in this manner and grounded. On the other hand, as the applying electrodes, a plurality of hollow rectangular pure titanium pipes coated with the same dielectric material as the above under the same conditions were prepared to form opposing electrode groups.

Further, the power source used for plasma generation was a high frequency power source JRF-10000 manufactured by JEOL Ltd. at a frequency of 13.56 MHz and a power of 5 W/cm ² and a mixed gas of 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 carried out under the above reaction gas and reaction conditions to prepare a silicon oxide film having a thickness of 18 nm as a moisture-proof film.

<Preparation of transparent conductive film>
A transparent conductive film was prepared by flowing a mixed gas having the following composition under the same atmospheric pressure plasma condition as that for forming 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
On the silicon oxide layer of the optical film 101 provided with the clear hard coat layer and the silicon oxide layer, atmospheric pressure plasma treatment is performed under 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) to obtain a transparent conductive film 1201.

<Transparent conductive film 1202-1206>
Similarly to the transparent conductive film 1201, transparent conductive films 1202 to 1206 were produced using the

optical film films

106, 107 and 110 to 112.
The following evaluations were performed on the transparent conductive films 1201 to 1206 thus obtained.

<<Evaluation>>
(Transmittance)
It was measured with TURBIDITY METER T2600DA manufactured by Tokyo Denshoku.

(Water vapor permeability evaluation)
The water vapor permeability was measured under the conditions (40° C., 90% RH) described in JIS Z-0208.

Also, measurements were performed after performing a series of 10 cooling-maturation cycles of heating at 180°C for 1 hour and then allowing to cool at room temperature for 1 hour.

(Specific resistance)
It was determined by the four-terminal method according to JIS R-1637. For the measurement, Mitsubishi Chemical Lorester cyclic polyolefin film GP, MCP-T600 was used.

After conducting the above evaluation, it was confirmed that the optical film of the present invention is an excellent conductive film support.

<Method of manufacturing organic EL element>
The transparent conductive film was used as the transparent conductive film, and a transparent conductive film (positive electrode) was patterned on the transparent conductive film. After that, ultrasonic cleaning was performed using a neutral detergent, acetone, and ethanol, and then the product was taken out from boiling ethanol and dried. Then, after ultrasonically cleaning the surface of the transparent conductive film, N,N-diphenyl-m-tolyl-4,4′-diamine-1,1′-biphenyl (TPD) was deposited at a deposition rate of 0.2 nm/in a vacuum deposition apparatus. It was vapor-deposited with a thickness of 55 nm in sec to form a hole injecting and transporting layer.

Further, Alq ₃ :tris(8-quinolinolato)aluminum was vapor-deposited at a vapor deposition rate of 0.2 nm/sec to a thickness of 50 nm to form an electron injection/transport light emitting layer. Then, a negative electrode was formed into a film with a thickness of 200 nm by a DC sputtering method using a sputtering apparatus with an Al.Su alloy (Su: 10 at%) as a target. Ar was used as the sputtering 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 applied power was 1.2 W/cm ² .
Finally, SiO ₂ was sputtered to a thickness of 200 nm as a protective layer to obtain an organic EL light emitting device. In this organic EL light-emitting element, two parallel stripe negative electrodes and eight parallel stripe negative electrodes are orthogonal to each other, and 2×2 mm vertical and horizontal element single elements (pixels) are arranged at an interval of 2 mm. , A 16-pixel element.

When the organic EL device thus obtained was driven at 9 V, the transparent conductive films 1201 to 1206 using the optical film of the present invention provided 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 an organic EL display having a high glass transition temperature and a low coefficient of linear expansion or a touch panel.

[Example 10]
The

optical films

101, 106, 107, 110 to 112 of the present invention produced in Example 1 were used as a base film (support) for nanoimprint.

(Mold fabrication by laser interference exposure)
A resist is spin-coated on a quartz glass substrate (thickness: 1.2 mm, 70 mm square). 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 beams with 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. Exposure. "MBD266 manufactured by Coherent Co." is used as the laser light source. Next, the quartz glass substrate is rotated by 90 degrees to form second interference fringes orthogonal to the first interference fringes, and second exposure is performed. In the first exposure and the second exposure, development is performed so that only the portions where the bright portions of the interference fringes cross each other remain. Through the above process, a resist in which holes having a pitch of 300 nm and a depth of 150 nm were regularly arranged was formed on the quartz glass substrate. A fine hole structure (pitch: 300 nm, depth: 150 nm) having a drawing size of 50 mm square was formed on the quartz glass by dry etching.

(Releasing process of quartz glass substrate)
Chlorinated fluororesin-containing silane coupling agent tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane [CF ₃ -(CF ₂ ) ₅ -CH ₂ -CH ₂ SiCl ₃ ] made of quartz glass The mold was surface-treated to form a fluororesin chemisorption film on the surface of the fine shape.

(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 1/20 (5%).

(Application of liquid composition)
The liquid crystal composition was applied to a quartz glass substrate with a wet film thickness of 80 μm using a wire bar.

(Lamination of film)
Within 5 seconds after applying the liquid composition, the

optical films

101, 106, 107, and 110 to 112 were adhered to and adhered to the applied liquid composition, respectively.

(Dry)
The quartz glass substrate coated with the liquid composition and the optical film were bonded together and dried at room temperature for 55 seconds.

(Release)
When the film was released from the mold after drying, 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 the pitch and height.

From the above, the

optical films

101, 106, 107, 110 to 112 of the present invention produced in Example 1 are excellent in being used as a base film (support) for nanoimprint.

[Example 11]
The

optical films

101, 106, 107, 110 to 112 of the present invention produced in Example 1 were used as a base film (support) for flexible electronic circuits.

(Preparation of substrate 1 with anchor layer)
<Synthesis of Polymerizable Compound 1 Having Ethylenically Unsaturated Group>
According to the following procedure, a polymerizable compound 1 having an ethylenically unsaturated group as a polymerizable group was synthesized.
To a 500 ml three-necked flask, 20 ml of ethylene glycol diacetate, 7.43 g of hydroxyethyl acrylate and 32.08 g of cyanoethyl acrylate were added, and after heating to 80° C., an oil-soluble azo polymerization initiator was added thereto. As a mixture of V-601 (dimethyl-2,2'-azobis(2-methylisopropionate)) (0.737 g) and ethylene glycol diacetate (20 ml) was added dropwise over 4 hours. Reacted for hours.

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 Karens AOI (acryloxyethyl isocyanate, Showa 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 liquid, and the reaction was further performed for 1.5 hours. After completion of the reaction, reprecipitation was carried out with water and the solid substance was taken out to obtain a polymerizable compound 1 having a nitrile group as an interactive group.

The polymerizable compound 1 was a repeating unit containing a polymerizable group (ethylenically unsaturated group):a repeating unit containing a nitrile group=22:78 (molar ratio). Moreover, 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 manufactured in Example 1 is used as a substrate, the surface thereof is subjected to oxygen plasma treatment, and then the anchor layer coating liquid 1 is applied by a spin coating method so that the film thickness after drying is 1.0 μm. And dried at 80° C. for 30 minutes.

<Curing treatment of anchor layer 1>
Then, using a UV irradiation lamp (model number: UVF-502S, lamp: UXM-501MD) manufactured by Sanei Denki, an irradiation power of 1.5 mW/cm2 (ultraviolet integrated light meter UIT150 manufactured by USHIO INC.-light receiving sensor UVD-S254) is used. The irradiation power was measured), and the anchor layer 1 was cured by irradiating ultraviolet rays under the condition that the integrated light amount was 500 mJ/cm ² . This curing condition is called condition A.

After the anchor layer 1 cured under the above condition A was isolated and subjected to extraction treatment in an acetone solution at 25° C. for 12 hours, the mass of the anchor layer before treatment was W1 (g), and the anchor layer after extraction with acetone. The gel fraction was calculated by the following equation, where W2 (g) was the mass of As a result of the measurement, the gel fraction of the anchor layer 1 was 93%.
Gel fraction (%)=(W2/W1)×100

<<Fabrication of metal pattern>>
[Fabrication of Metal Pattern 1]
Using the above-prepared substrate 1 with an anchor layer, a metal pattern 1 was prepared according to the following metal pattern forming step.

(Metal pattern forming process)
1: Catalyst ink applying step 2: Drying step 3: Surface treatment step 4: Activation step 5: Electroless plating step 6: Electroplating step

(1: step of applying catalyst ink)
<Preparation of catalyst ink 1>
Catalyst ink 1 was prepared by mixing the following additives.
Electroless plating catalyst precursor: Palladium acetate: 0.05% by mass
Diethylene acetate: 79.95% by mass
t-Butyl alcohol: 20% by mass

<Applying catalyst ink 1>
Using the ink jet recording head, the catalyst ink 1 prepared above was drawn on the anchor layer of the formed substrate 1 with an anchor layer by pattern drawing of lines and spaces of 75 μm, 100 μm, 150 μm, and 200 μm to prepare Sample 1 Was produced.
As the inkjet recording head used, a 512S head manufactured by Konica Minolta Co., Ltd. capable of ejecting ink droplets of 4 pl size by a piezo method was used.

(2: Drying process)
After applying the catalyst ink 1, warm air at 50° C. was blown onto the catalyst ink application surface for 10 minutes to dry the surface.

(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 mass% solution of a plating conditioner (trade name: PC-321, manufactured by Meltac Co.) containing a nonionic surfactant at 60° C. for 5 minutes to perform surface treatment.
As a result of measuring the contact angle 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 process)
Then, the surface-treated sample 1 was immersed in the following activation liquid at 35° C. for 10 minutes to perform the activation treatment.

<Activation liquid>
"Measure by photographing either the reflected light or the transmitted light emitted from the opposite surface.
Alcup MRD2-A (manufactured by Uemura Industry Co., Ltd.): 18 ml
Alcup MRD2-C (made by Uemura Industries): 60 ml
It was made up to 1000 ml with pure water.

(5: Electroless plating process)
After adjusting the pH of the electroless copper plating solution described below to 13.0 with sodium hydroxide, the electroless plating process was performed on the sample 1 subjected to the 5: activation process at a temperature of 50° C. to about 0. A copper plating layer having a thickness of 0.2 μm was formed.

<Electroless copper plating solution>
Melplate CU-5100A (Meltex): 60 ml
Melplate CU-5100B (manufactured by Meltex): 55 ml
Melplate CU-5100C (Meltex): 20 ml
Melplate CU-5100M (Meltex): 40 ml
It was made up to 1000 ml with pure water.

The above 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 above electroless plating treatment is immersed in an electroplating bath, a copper plate is used as an anode, and electroplating is performed at a current density of 1.5 A/dm ² to form a copper film of about 15 μm, and a metal pattern is formed. 1 was produced.

<Preparation of electroplating bath>
Copper sulfate pentahydrate: 60 g
Sulfuric acid: 190 g
Chloride ion: 50mg
Copper Gleam PCM (Meltex): 5 ml
It was made up to 1000 ml with pure water.

Similar to the above steps, the

optical films

106, 107, 110 to 112 were used as base films (supports) for flexible electronic circuits.

<<Evaluation of metal pattern>>
The following respective evaluations were performed on each of the metal patterns produced above.

[Evaluation of plating quality]
The line and space patterns of 75 μm, 100 μm, 150 μm, and 200 μm drawn on the sample processed to the electroless plating step of each metal pattern were visually observed, and the image quality was evaluated according to the following criteria.

◯: In the line & space pattern after completion of electroless plating, there is no abnormal deposition outside the printed area, and there is no deterioration in plating gloss or cracks, which is of good quality. Δ: Line & space after completion of electroless plating In the space pattern, a slight amount of abnormal deposition occurs outside the printed area, but no reduction in gloss or cracks of the plating is observed. ×: In the line & space pattern after completion of electroless plating, abnormal deposition outside the printed area One of the following is the decrease in the gloss of the plating and the occurrence of cracks.

[Evaluation of durability (adhesion resistance) under high temperature and high humidity environment]
Each of the metal patterns prepared above was stored in a high temperature and high humidity environment of 80° C. and 90% RH for 7 days, and then immediately subjected to heat treatment on a hot plate of 240° C. and 260° C. to obtain a substrate and a copper plating pattern. Adhesion between them (whether or not blister was generated) was visually observed, and 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 blisters are observed, but some blisters are observed when heated at 260°C. x: Blistering is clearly observed between the substrate and the copper plating pattern when heated to 240°C on a hot plate. When the above-mentioned evaluation is performed, all the samples in which the metal patterns are produced using the

optical films

101, 106, 107, 110 to 112 of the present invention are evaluated as Δ to ◯, and are excellent for flexible electronic circuits. It was found to be a base film (support).

[Example 12]
The

optical films

101, 106, 107, 110 to 112 of the present invention produced in Example 1 were used as the base film (support) of the anti-counterfeit 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 coating liquid AL-1 for 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 an alignment layer coating liquid AL-2.

<Alignment layer coating liquid AL-2 composition>
Liquid crystal aligning agent (AL-1-1): 1.0% by mass
Tetrahydrofuran: 99.0 mass%

(Preparation of coating liquid LC-1 for optically anisotropic layer)
After the following composition was prepared, 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 the two reactive groups is an acrylic group which is a radical reactive group, and the other is an oxetane group which is a cationic reactive group. is there.

<Coating liquid composition for optically anisotropic layer>
Polymerizable liquid crystal compound (LC-1-1): 32.88% by mass
Horizontal aligning agent (LC-1-2): 0.05% by mass
Cationic photopolymerization initiator (CPI100-P, manufactured by San-Apro Ltd.): 0.66% by mass
Polymerization control agent (IRGANOX 1076, manufactured by BASF Japan Ltd.): 0.07% by mass
Methyl ethyl ketone: 46.34 mass%
Cyclohexanone: 20.00 mass%

(Preparation of coating liquid LC-2 for optically anisotropic layer)
After the following composition was prepared, 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 (Paliocolor 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 (Megaface F-176PF (trade name, manufactured by DIC Corporation)): 0.15% by mass
Methyl ethyl ketone: 67.00 mass%

(Preparation of additive layer OC-1)
After the following composition was prepared, 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 mass%

(Preparation of birefringence pattern builder P-1)
Aluminum having a thickness of 60 nm was vapor-deposited on the optical film 101 to prepare a support with a reflective layer. The coating liquid AL-1 for alignment layer was applied to the aluminum-deposited surface using a wire bar and dried. The dry film thickness was 0.5 μm. After rubbing the alignment layer, a coating liquid LC-1 for an optically anisotropic layer is applied using a wire bar and dried at a film surface temperature of 90° C. for 2 minutes to be in a liquid crystal phase state. /Cm of an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) was used to irradiate with ultraviolet rays to fix the orientation state to form an optically anisotropic layer having a thickness of 4.5 μm. The illuminance of the ultraviolet ray used at this time was 500 mW/cm ^{2 in} the UV-A region (accumulation of wavelength 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 additive layer coating liquid OC-1 was applied onto the optically anisotropic layer and dried to form an additive layer having a thickness of 0.8 μm, whereby a birefringence pattern builder P-1 was prepared.

(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 Was used for pattern exposure by roll-to-roll. 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 did. Then, using a far-infrared heater continuous furnace, the film was heated for 20 minutes by a roll-to-roll method so that the film surface temperature was 210° C., to prepare an article P-2 having a birefringence pattern. When a polarizing plate (HLC-5618, manufactured by Sanritz Co., Ltd.) is held over the article P-2, the birefringence pattern applied to the article P-2 can be confirmed when held in a predetermined direction. It was An enlarged view of the pattern observed on the article P-2 through the polarizing plate is shown in FIG. In the figure, a two-color pattern is observed in which the ground aluminum foil is silvery, while the lattice is dark blue or light blue and the shaded area is yellow or orange.

(Anti-counterfeit medium B:: Optical axis patterned birefringence pattern)
60 nm of aluminum was vapor-deposited on the optical film 101. Then, the coating liquid AL-2 for alignment layer was applied onto aluminum using a wire bar and dried. The dry film thickness was 0.1 μm.

The photomask A shown in FIG. 44 is arranged on the obtained organic film, and the light emitted from the ultraviolet light emitted from the ultraviolet irradiator (manufactured by HOYACANDEO OPTRONICS, trade name: EXECURE3000) is converted into a linear polarizing plate. The substrate was irradiated through the substrate at an intensity of 100 mW/cm ² (365 nm) for 1 second from the direction perpendicular to the substrate. 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 sequentially changed to B, C, and D shown in FIG. 44 so that the absorption axes of the linear polarization plates are 45°, 90°, and 135° with respect to the long sides of the photomask, respectively. After arranging, was similarly irradiated with ultraviolet rays.

Then, the coating liquid LC-2 for an optically anisotropic layer is applied using a wire bar, dried at a film surface temperature of 105° C. for 2 minutes to be in a liquid crystal phase state, and then air-cooled at 160 mW/cm ² under air. An optically anisotropic layer having a thickness of 0.9 μm is obtained by irradiating ultraviolet rays having an illuminance of 400 mW/cm ² and an irradiation amount of 400 mJ/cm ² using a metal halide lamp (manufactured by Eye Graphics Co., Ltd.) to fix the alignment state. By forming, the 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 the background 215 of the anti-counterfeit medium B were 0°, 45°, 90°, and 135° with respect to the long sides, respectively. In addition, the retardation in each of these regions was 135 nm (λ/4).

(Production Example 1)
The anti-counterfeit medium A was treated with a surface modification device MEIR-5-600 (manufactured by MD Excimer). After that, letters and patterns were relief-printed using UV161 black ink, red, indigo, and yellow (manufactured by T&K). After that, dry lamination was performed using Suncut PL Shin 7LK (manufactured by Lintec Co., Ltd., front retardation=5 nm, film thickness 50 μm), and an anti-counterfeit medium of Production Example 1 was produced.

(Production Example 2)
An anti-counterfeit medium of Production Example 2 was produced in the same manner as in Production Example 1 except that anti-counterfeit medium A was changed to anti-counterfeit medium B.

(Production Example 3)
Forgery prevention medium of Production Example 3 is the same as Production Example 1 except that a sun blasted PLSIN 7LK (manufactured by Lintec Co., Ltd., front retardation=5 nm, film thickness 50 μm) whose surface is sandblasted is used as the laminate film. Was produced.

(Production Example 4)
Variable information was printed on the anti-counterfeit medium of Production Example 1 with KI ink using LUXEL JET UV250GT (manufactured by FUJIFILM Corporation). In this way, the anti-counterfeit medium of Production Example 4 was produced.

(Production Example 5)
The anti-counterfeit medium A was treated with a surface modification device MEIR-5-600 (manufactured by MD Excimer). Then, printing was performed with KI ink using LUXEL JET UV250GT (manufactured by FUJIFILM Corporation). After that, dry lamination was performed using a sun cut PL Shin 7LK (manufactured by Lintec Co., Ltd., front retardation=5 nm, film thickness 50 μm) to prepare a forgery prevention medium of Production Example 5.

(Production Example 6)
The anti-counterfeit medium A was treated with a surface modification device MEIR-5-600 (manufactured by MD Excimer). Thereafter, letters and patterns were letterpress-printed using UV flexo 500 ink, red, indigo, and yellow (manufactured by T&K). After that, dry lamination was performed using a sun cut PL Shin 7LK (manufactured by Lintec Co., Ltd., front retardation=5 nm, film thickness 50 μm) to manufacture a forgery prevention medium of Production Example 6.

(Production Example 7)
The anti-counterfeit medium A was treated with a surface modification device MEIR-5-600 (manufactured by MD Excimer). After that, characters and designs were screen printed. After that, dry lamination was performed using a sun cut PL Shin 7LK (manufactured by Lintec Co., Ltd., front retardation=5 nm, film thickness 50 μm) to manufacture a forgery prevention medium of Production Example 6.

(Production Example 8)
An anti-counterfeit medium of Production Example 8 was produced in the same manner as in Production Example 1 except that KES25N Matt PL Shin 7LK (manufactured by Lintec Corporation, front retardation=33 nm, film thickness 25 μm) was used as the laminate film.

(Production Example 9)
As a laminate film, triacetyl cellulose (trade name: TDP, manufactured by FUJIFILM Corporation, front retardation = 1 nm, film thickness 60 μm) is pasted with an adhesive (trade name: Z2-25, manufactured by Panac Co., Ltd.) An anti-counterfeit medium of Production Example 9 was produced in the same manner as in Production Example 1 except for using the above.

Similarly, the

optical films

106, 107, 110 to 112 were used as the base film (support) of the anti-counterfeit medium.

Each of the anti-counterfeit media of Production Examples 1 to 9 was excellent in latent image visibility, and was excellent in durability because the print did not peel off by the tape adhesion test and the scratch resistance test. Therefore, it was found that the optical film of the present invention can be preferably used as a base film (support) of a medium for preventing forgery.

The present invention can be used for a method for producing a highly durable, tough and homogeneous acrylic resin film that does not cause optical disorder on the surface and inside.

DESCRIPTION OF SYMBOLS 1 Melting kettle 2

Pumps

3, 6, 12, 15

Filtration machine

4, 13

Stock tank

5, 14

Liquid sending pump

8, 16 Conduit 10 Ultraviolet absorber charging pot 20 Combiner 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 Stocking pot 42 Stock tank 43 Pump 44 Filter 100 Main filtering device 102 Ultrafiltration device 103 Stationary tank (stock tank)
104 Dope flow pipe (flow pipe)
105 Pump 106 Diluting Solvent Tank 107 Solvent Injecting Pipe 108 Piping 110 Casting Die 111 Endless Support 112 Peeling Roll 113 Opening Valve 114 Opening Valve 115 Opening Valve 116 Opening Valve 117 Opening Valve 118 Solvent Discharge Pipe 119 Solvent Reuse Return Pipe 212 Letter A
213 letter B
214 letter C
215 Background 372 Decanter 381 Crude hydrophilic solvent tank 382 Crude hydrophobic

solvent tank

383, 385 Distillation column 384 Hydrophilic solvent tank 386 Hydrophobic solvent tank

Claims

Acrylic resin, a method for producing an acrylic resin film containing 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 4,000,000 and rubber particles having a core-shell structure; ,
Preparing a dope by filtering the dope with a filter having a filtration accuracy within the range of 5 to 100 μm;
A step of casting the dope after filtration on a support and peeling the web,
And a step of drying the web, and
An acrylic resin having a transmission image clarity C value within a range of 80 to 100% when measured under the condition that a parallel light ray is incident on the acrylic resin film at an angle of 75 degrees and an optical comb width is 0.125 mm. Film manufacturing method.
The method for producing an acrylic resin film according to claim 1, wherein the content of the rubber particles having the core-shell structure is within 5 to 20 mass% with respect to the acrylic resin film.