KR101381530B1 - Method for producing optical film, optical film, polarizing plate and display - Google Patents

Abstract

It aims at providing the manufacturing method of the optical film which is excellent in productivity, suppresses generation | occurrence | production of the interference fringe between the hard-coat layer, and the layer which contact | connects the base material side of a hard-coat layer, and is excellent in visibility. A process for preparing a light-transmissive base material, the first resin and the first solvent, the low refractive index component is not included or the low refractive index component is 5.0% by mass or less with respect to the mass of the first resin, the viscosity μ1 is 3mPa. A process for preparing a second composition comprising a first composition having a s or more, and a low refractive index component, a second resin, and a second solvent, wherein the viscosity has a mu m of 5 mPa · s or more and a difference between mu 2 and mu 1 is 30 mPa · s or less, a light transmissive substrate At least one of the first composition and the second composition adjacent to one surface side of the light transmissive substrate side and simultaneously coating the coating film, and drying the coating film, followed by curing with light irradiation or heating. It is a manufacturing method of the optical film characterized by not pre-curing before drying.

Description

Method for manufacturing optical film, optical film, polarizer and display {METHOD FOR PRODUCING OPTICAL FILM, OPTICAL FILM, POLARIZING PLATE AND DISPLAY}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an optical film provided on a front surface of a display (image display device) such as a liquid crystal display (LCD), a cathode ray tube display (CRT), or a plasma display (PDP), a manufacturing method thereof, and a polarizing plate and a display using the same. will be.

In such a display, in order to improve the visibility of the display surface, it is required that the reflection of the light beam irradiated from an external light source such as a fluorescent lamp or sunlight is required to be small. As a method of suppressing reflection of external light, the method of using the antireflection film which provided the low refractive index layer in the outermost surface of functional layers, such as a hard-coat layer, is known (for example, patent document 1).

However, as in the invention of Patent Literature 1, the composition for forming a functional layer is applied, semi-cured with ionizing radiation to form a functional layer, and the composition for forming a low refractive index layer is completely cured by applying a composition on the semi-cured functional layer. In order to apply | coat a composition (semi-curing system) and the conventional middle layer coating system which apply | coats a composition for each conventional layer, and to fully harden, since a several application | coating process and a hardening process are performed, productivity is not good.

On the other hand, in patent document 2, two or more functional layers can be apply | coated at the same time, and high productivity is obtained, adhesiveness between layers is high, and the manufacturing method of the optical film which does not interfere with the functional separation in each layer. A layer and a B layer which contain an ionizing radiation curable resin are apply | coated at the same time, respectively, carrying out the 1st ionizing radiation irradiation (preliminary hardening), and then drying, and carrying out the 2nd ionizing irradiation The manufacturing method of the optical film which performs and hardens | cures (complete hardening) is proposed.

However, in addition to the high adhesion between the layers coated with the middle layer, a high adhesion between the layer coated with the layer and the substrate or the layer in contact with the substrate side is also required. In patent document 2, although the adhesiveness between layers was high and the function between each layer was isolate | separated, the layer interface existed between A layer (hard coat layer or anti-glare layer) and B layer (refractive-index control layer) which were apply | coated simultaneously. .

In addition, although the patent document 1 contains low refractive index microparticles | fine-particles, such as a hollow particle, intention to reduce the refractive index of a low refractive index layer, when the low refractive index microparticles are contained in a low refractive index layer in this way, the refractive index of a low refractive index layer will reduce, Since the functional layer in contact with the substrate side of the low refractive index layer has a higher refractive index than the low refractive index layer, there is a difference in refractive index between the low refractive index fine particles of the low refractive index layer and the functional layer at the interface (interface) of the low refractive index layer and the functional layer. If thickness control is not performed, interference fringes will generate | occur | produce, and there existed a problem that the visibility of the display surface of the display using an antireflection film falls.

Japanese Patent Publication No. 2009-053691 Japanese Patent Application Laid-Open No. 2008-250267

The present invention has been made to solve the above problems, and the first object of the present invention is to have a reflection preventing function by performing simultaneous coating (layer coating), while maintaining a surface shape without haze, total light transmittance, and stripes, By reducing the coating step and curing step, the productivity is improved, and by eliminating the interface between the layers due to the sequential coating, the generation of interference fringes between the layers is suppressed and the adhesion is improved. By increasing the ratio of the hard coat composition having a refractive index, it is possible to provide an optical film and a method for producing the same, which suppress the occurrence of interference fringes between the hard coat layer and the substrate and are excellent in adhesion.

The 2nd object of this invention is to provide the polarizing plate provided with the said optical film.

A third object of the present invention is to provide a display provided with the optical film.

As a result of earnestly examining by the present inventors, even if it does not contain the low refractive index microparticles | fine-particles and low refractive index resin, or contains the low refractive index resin, it is less than 5 mass% with respect to the mass of curable resin containing a photocurable resin and a thermosetting resin, A first composition having a specific viscosity and a second composition containing low refractive index fine particles and having a specific viscosity are formed on the substrate or on a layer formed on the substrate by adjoining the first composition and the second composition from the substrate side. By applying simultaneously, drying without pre-curing before drying, and subsequently curing with light irradiation or heating, the low refractive index fine particles in the film thickness direction of the HC layer are larger than the substrate side on the interface side opposite to the substrate of the HC layer. Distribution on the substrate side, that is, the amount of low refractive index fine particles is smaller, that is, the system on the side opposite to the substrate. The low refractive index microparticles | fine-particles are gradually taken over from the side to the base material side, and it is the same as the case where the conventional low refractive index layer and HC layer were formed by sequential intermediate | middle application, or when they were formed by simultaneous coating like patent document 2 It does not exhibit a clear layer interface and has an antireflection function, while maintaining the surface shape without haze, total light transmittance, and stripe, while suppressing the generation of interference fringes between layers by eliminating the interface between layers by sequential coating, In the vicinity of the substrate, by increasing the ratio of the hard coat composition having the same refractive index as that of the substrate, the occurrence of interference fringes between the hard coat layer and the substrate is suppressed, and the optical film having excellent adhesion is high. It discovered that it is obtained by productivity, and came to complete this invention.

That is, the manufacturing method of the optical film which concerns on this invention contains the process of (i) preparing a light transmissive base material, (ii) the 1st resin and the 1st solvent which have reactivity, and also the low refractive index microparticle and the low refractive index resin Curable resin composition for a first hard coat layer having a viscosity of not more than 5.0 mass% or less with respect to the mass of the first resin and a viscosity μ1 of 3 mPa · s or more, and a low refractive index having an average particle diameter of 10 to 300 nm One or more low refractive index components selected from the group consisting of fine particles and low refractive index resins, a second resin having a reactivity, and a second solvent, and having a viscosity of? 2 of 5 mPa · s or more, A step of preparing a curable resin composition for a second hard coat layer of 30 mPa · s or less, (iii) at least on the first transparent surface from the light-transmitting substrate side on one side of the light-transmissive substrate. The curable resin composition for a hard-coat layer and the curable resin composition for a 2nd hard-coat layer adjoin and apply | coat simultaneously, and make into a coating film, (iv) Dry the coating film obtained by said (iii) process, and continue light irradiation and / or heating. And a step of curing, and further, preliminary curing is not performed between the step (iii) and the step (iv).

Curable resin composition for 1st HC layer which does not contain low refractive index microparticles | fine-particles and low refractive index resin, or contains low refractive index resin, and is less than 5.0 mass% with respect to the mass of a 1st resin, and has the said specific viscosity (hereinafter, simply It may be called 1 composition), and 1 or more types of low refractive index components chosen from the group which consists of low refractive index microparticles | fine-particles and low refractive index resin, and has the said specific viscosity curable resin composition for 2nd HC layers (it simply follows 2 composition) may be applied from the light-transmitting substrate side at the same time so that the first composition and the second composition are positioned adjacent to each other to form an HC layer and not perform precuring, thereby reducing the low refractive index included in the second composition. The component is a light transmissive substrate on the interface side on the side opposite to the light transmissive substrate of the HC layer in the film thickness direction of the HC layer. It exists more than the side, and it is distributed so that the abundance of low refractive index components may become smaller on the light transmissive base material side, and the said low refractive index component gradually decreases from the interface on the opposite side to a light transmissive base material to the light transmissive base material side, and in HC layer The optical film which suppresses generation | occurrence | production of the interference fringe by the refractive index difference of resin of a low refractive index component and HC layer, and generation | occurrence | production of the interference fringe at the interface of HC layer and a base material, and is excellent in visibility is obtained.

Then, the coating film is dried without preliminary curing, and subsequently the light coating or heating is performed to cure the coating film. Therefore, the coating layer is in contact with the HC layer, the light-transmissive substrate, or the light-transmissive substrate side of the HC layer, as compared with the case of precuring and curing. Adhesion with a layer can be improved. In this invention, precure means light irradiation and / or heating which does not harden a coating film. And this hardening of a coating film dries a coating film, reduces the solvent in a coating film, and the hardened coating film expresses hardness more than "H" by the pencil hardness test (4.9N load) prescribed | regulated to JISK5600-5-4 (1999). It means hardening.

In suitable embodiment of the manufacturing method of the optical film which concerns on this invention, in the said (iii) process, the wet film thickness of the coating film of the curable resin composition for 1st hard-coat layers is made of T1, the curable resin composition for 2nd hard-coat layers. When the wet film thickness of the coating film is T2, the value of T2 divided by T1, that is, T2 / T1 is 0.01 to 1, so that the low refractive index component in the film thickness direction of the hard coat layer is different from that of the light-transmissive substrate of the HC layer. It exists more in the interface side on the opposite side than the light transmissive substrate side, and it is distributed so that the abundance of the low refractive index component may become smaller on the light transmissive substrate side, and the said low refractive index component is spread from the interface on the opposite side to the light transmissive substrate side. This gradually decreases, and in the film thickness direction of the hard coat layer, 70 of the dry film thickness of the hard coat layer from the interface on the side opposite to the light transmissive substrate. It is also possible to obtain the optical film which has a distribution in which 70 to 100% of the total amount of the said low refractive index component exists in the area | region up to%.

Thus, since the low refractive index component is distributed, even if the content of the low refractive index component is reduced, the antireflection performance of the optical film can be sufficiently expressed.

In addition, distribution of the low refractive index microparticles | fine-particles in the film thickness direction of HC layer can be observed with the TEM (transmission electron microscope) photograph of the film thickness direction cross section of HC layer.

The distribution of the low refractive index resin in the film thickness direction of the HC layer is, for example, an optical film is embedded using a thermosetting resin, and from the embedded optical film, an ultra-thin slice having a thickness of 80 nm using an ultra microtome manufactured by Leica (LEICA). It can be measured by producing a film, followed by vapor phase staining using RuO 4, and observing by TEM.

In a preferred embodiment of the method for producing an optical film according to the present invention, the viscosity μ1 of the curable resin composition for the first hard coat layer is 3 to 95 mPa · s, and the viscosity μ2 of the curable resin composition for the second hard coat layer is 5 to 5. It is preferable that it is 100 mPa · s because the HC layer having the distribution of the specific low refractive index component is easily obtained.

The optical film which concerns on this invention is an optical film obtained by the manufacturing method of the said optical film.

In suitable embodiment of the optical film which concerns on this invention, it is an optical film in which the hard-coat layer was formed in the one surface side of a transparent base material, and low refractive index microparticles | fine-particles are the opposite side to the said transparent base material in the film thickness direction of the said hard-coat layer. The amount of the low refractive index fine particles is smaller on the interface side than on the light transmissive substrate side, and on the light transmissive substrate side, the amount of the low refractive index fine particles is smaller, and the low refractive index component is spread from the interface on the opposite side to the light transmissive substrate. It gradually decreases, and there is no layer interface in the said hard-coat layer, and it is also possible to make the adhesiveness of the board | substrate graduation adhesion test with respect to the said light-transmissive base material of the said hard-coat layer into 90 to 100%.

Here, the adhesion rate of the checkerboard scale adhesiveness test puts a total of 100 checkerboard scales in the square of 1 mm on one side to the HC layer side surface of an optical film, and is 24 mm in width | variety adhesive tape (for example, Nichiban Co., Ltd. product made). It is the ratio of the scale which remained without peeling computed based on the following reference | standard by performing 5 times continuous peeling tests using industrial cello tape (trademark).

Adhesion rate (%) = (number of scales not peeled off / total number of scales 100) × 100

In a preferred embodiment of the optical film according to the present invention, in the film thickness direction of the hard coat layer, in the region from the interface on the side opposite to the light transmissive substrate to 70% of the dry film thickness of the hard coat layer, the low It is also possible that 70 to 100% of the total amount of the refractive index fine particles is present.

The polarizing plate which concerns on this invention is provided with the polarizer in the light transmissive base material side opposite to the said hard-coat layer of any one of said optical films, It is characterized by the above-mentioned.

The display according to the present invention is characterized in that a display panel is arranged on the light transmissive substrate side opposite to the hard coat layer of any one of the above optical films.

The first composition having the specific amount, the first composition having the specific viscosity, and the low refractive index fine particles and / or the low refractive index resin even when the low refractive index fine particles and the low refractive index resin are not included or the low refractive index resin is included, and the specific viscosity is included. By simultaneously applying a second composition having a composition so that the first composition and the second composition are adjacent to each other from the light-transmissive substrate side, drying the coating film without preliminary curing, and subsequently performing light irradiation or heating to form the HC layer, The low refractive index microparticles | fine-particles and / or low refractive index resin which are contained in a 2nd composition exist in the film thickness direction of HC layer more in the interface side on the opposite side to the light transmissive base material of HC layer than the light transmissive base material side, and are also light transmissive. It is distributed so that the abundance amount becomes smaller as the base material side, and it is a light transmissive base material from the interface on the opposite side to a light transmissive base material. The low-refractive index component is distributed gradually to decrease, has an antireflection function, improves productivity by reducing the coating process and the curing process while maintaining the surface shape without haze, total light transmittance, and streaks, and also sequentially applying By eliminating the interface between the layers, the occurrence of interference fringes between the layers can be suppressed, the adhesion can be improved, and in the vicinity of the substrate, the ratio of the hard coat composition having the same refractive index as that of the substrate is increased so as to increase the The optical film which suppresses generation | occurrence | production of the interference fringe between them and is excellent in adhesiveness is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The cross-sectional schematic diagram which shows an example of distribution of the low refractive index microparticles | fine-particles in HC layer of the optical film obtained by the manufacturing method of this invention.
FIG. 2 is a cross-sectional schematic diagram showing an example of distribution of low refractive index fine particles in a low refractive index layer of an antireflection film obtained by a conventional sequential multilayer coating method. FIG.
It is a schematic diagram which shows an example of the process of simultaneously apply | coating the curable resin composition for 1st and 2nd HC layers in the manufacturing method of the optical film which concerns on this invention.
It is a schematic diagram which shows an example of the laminated constitution of the 2nd optical film of this invention.
It is a schematic diagram which shows another example of the laminated constitution of the 2nd optical film of this invention.
6 is a schematic diagram showing an example of a layer structure of a polarizing plate of the present invention.
7 is a cross-sectional view of the optical film of Example 1. FIG.
8 is an enlarged cross-sectional view of an interface portion on the side opposite to the light transmissive substrate of the hard coat layer of the optical film of Example 1. FIG.
9 is a sectional view of an optical film of Comparative Example 3. FIG.

Hereinafter, the manufacturing method of the optical film which concerns on this invention is demonstrated first, and the said optical film is demonstrated subsequently.

In the present invention, (meth) acrylate represents acrylate and / or methacrylate.

In addition, the light of the present invention includes not only electromagnetic waves of wavelengths in the visible and invisible regions, but also particle beams such as electron beams and radiation or ionizing radiation which collectively refer to electromagnetic waves and particle beams.

In this invention, unless otherwise indicated, a film thickness means the film thickness at the time of drying (dry film thickness).

In the present invention, the "hard coat layer" refers to a hardness of "H" or more in a pencil hardness test (4.9 N load) defined in JIS K5600-5-4 (1999).

In addition, in the definition of film and sheet in JIS-K6900, a sheet refers to a flat product which is thin and generally whose thickness is smaller than the length and width, and the film is extremely small compared to the length and width, and the maximum thickness is arbitrarily defined. It is a thin flat product, usually referred to as supplied in the form of a roll. Therefore, although the thickness is especially thin among sheets, since the boundary of a sheet | seat and a film is not clear, and it is difficult to distinguish clearly, in this invention, both the thickness and the thin meaning include " Film ”.

In this invention, resin is a concept containing a polymer other than a monomer and an oligomer, and means the component used as a matrix of HC layer and another functional layer after hardening.

In the present invention, the molecular weight means a weight average molecular weight which is a polystyrene conversion value measured by gel permeation chromatography (GPC) in a THF solvent when it has a molecular weight distribution, and the compound itself when it does not have a molecular weight distribution. It means the molecular weight of.

In the present invention, the average particle diameter of the low refractive index fine particles means that in the case of the fine particles in the composition, the particles in the solution are measured by a dynamic light scattering method, and the particle size distribution including the primary particle size and the secondary particle size is represented by a cumulative distribution. It means the 50% particle diameter (d50 median diameter) at the time, and can measure it using the Microtrac particle size analyzer made by Nikkiso Corporation. In the case of microparticles | fine-particles in HC layer, the mean value of 20 particle | grains observed by the TEM photograph of the cross section of HC layer is meant.

(Method for producing optical film)

The manufacturing method of the optical film which concerns on this invention contains the process of (i) preparing an optically transparent base material, (ii) the 1st resin and the 1st solvent which have reactivity, and do not contain low refractive index microparticles | fine-particles and low refractive index resin. Or a low refractive index resin, the curable resin composition for a first hard coat layer having a viscosity of not more than 5.0% by mass with respect to the mass of the first resin and having a viscosity μ1 of 3 mPa · s or more, low refractive index fine particles having an average particle diameter of 10 to 300 nm, and 30 mPa * including the 1 or more low-refractive-index components selected from the group which consists of low refractive index resins, the 2nd resin which has reactivity, and a 2nd solvent, and subtracting the said μ1 from the said μ2 with a viscosity (micro) 2 of 5 mPa * s or more. Process of preparing curable resin composition for 2nd hard-coat layers which are s or less, (iii) On the one surface side of the said transparent base material, From the said transparent base side at least from said 1st lower A step of coating the curable resin composition for the coat layer and the curable resin composition for the second hard coat layer adjacent to each other to form a coating film, and (iv) drying the coating film obtained in the step (iii), followed by light irradiation and / or heating. A step of hardening is included, and precure is not performed between the step (iii) and the step (iv).

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows an example of distribution of the low refractive index microparticles | fine-particles in HC layer of the optical film obtained by the manufacturing method of this invention.

In the optical film 1, the HC layer 20 is formed on one surface side of the light transmissive substrate 10, and the low refractive index fine particles 30 in the HC layer are disposed on the interface side opposite to the light transmissive substrate of the HC layer. It exists more than the light transmissive base material side, and has a distribution in which the quantity of abundance is small, that is, the said low refractive index component gradually decreases from the interface on the opposite side to a light transmissive base material from the light transmissive base material side.

It is a cross-sectional schematic diagram which shows an example of distribution of the low refractive index microparticles | fine-particles in the low refractive index layer of the antireflection film by the conventional sequential middle layer coating method.

In the antireflection film 100, the HC layer 110 and the low refractive index layer 120 are formed on one surface side of the light transmissive substrate 10 from the light transmissive substrate side, and the low refractive index fine particles 30 are formed in the low refractive index layer. Is uniformly distributed, but since the low refractive index layer is formed after the HC layer is completely cured, the low refractive index fine particles are not present in the HC layer, and the difference in refractive index is large at the interface between the low refractive index layer and the HC layer, resulting in interference fringes. I did it. In addition, the interface between the HC layer and the low refractive index layer can also be clearly identified. In addition, when a low refractive index layer having a thick film thickness about the same as the thickness of the region in which the low refractive index microparticles | fine-particles of FIG. 1 exist is formed with the conventional antireflection film, interference fringes generate | occur | produced.

Thus, in the conventional sequential middle layer coating method, when the upper layer (low refractive index layer) of the same thickness as the thickness in which the low refractive index microparticles | fine-particles obtained by the coating method of this invention is distributed is formed, the hardened part of the composition used as a lower layer, and An interface was generated in the cured portion of the upper layer composition, and the interference fringes occurred because the difference in refractive index between the low refractive index fine particles contained in the upper layer composition at the interface portion and the resin contained in the lower layer composition was large.

On the other hand, in the manufacturing method of the optical film which concerns on this invention, even if it does not contain low refractive index microparticles | fine-particles and low refractive index resin, or contains low refractive index resin, it is 5.0 mass% or less with respect to the mass of a 1st resin, The said specific viscosity And a first composition having a low refractive index component, and a second composition having the specific viscosity, being co-coated so that the first composition and the second composition are positioned adjacent to each other from the light transmissive substrate side to form an HC layer and preliminarily. By not hardening, as shown in FIG. 1, the low-refractive-index component contained in a 2nd composition is a light transmissive base material side on the interface side opposite to the light transmissive base material of HC layer in the film thickness direction of HC layer. More present and the light transmissive substrate side has a smaller amount of low refractive index fine particles, i.e., an interface side opposite to the light transmissive substrate. From the light transmissive substrate side, the low refractive index component is gradually decreased, and the generation of interference fringes caused by the difference in refractive index between the low refractive index component and the resin of the HC layer in the HC layer and the interface between the HC layer and the substrate The generation of interference fringes is suppressed, and the optical film which is excellent in visibility and excellent in the adhesiveness of HC layer and the layer which contact | connects a light transmissive base material or the light transmissive base material side is obtained.

Moreover, since it is not necessary to precure, it is excellent also in productivity compared with the case where it hardens by performing 2 times light irradiation of precure and this hardening.

Moreover, when HC layer containing low refractive index microparticles | fine-particles as a low refractive index component is formed by simultaneous application | coating on a transparent base material, the reason why the adhesiveness of the said HC layer and the said transparent base material is good is not clear, but the following reasons I guess. That is, when the resin contained in the first composition is in contact with the light transmissive substrate, the resin penetrates into the light transmissive substrate and chemical and / or physical bonds occur, which is supposed to improve the adhesion between the HC layer and the light transmissive substrate. do. On the other hand, when the low refractive index microparticles | fine-particles contained in HC layer are disperse | distributed uniformly in HC layer, without taking the distribution that the amount of abundance is less in the light transmissive substrate side as mentioned above, in the interface of the light transmissive substrate side in HC layer, As much as the portion occupied by the low refractive index fine particles, it is estimated that the chemical and / or physical bonding between the resin and the substrate due to the penetration of the resin does not occur, and the adhesion does not increase.

In addition, if precuring is carried out immediately after simultaneously applying a 1st composition and a 2nd composition on a light transmissive base material, superposition | polymerization or crosslinking will start before resin infiltrates a light transmissive base material in presence of a solvent, and the molecular weight of resin will become large and resin It is guessed that adhesiveness does not increase even if it does not penetrate into a light transmissive base material, and even if it irradiates or heats after drying.

In this respect, when the first composition and the second composition are simultaneously applied on the light-transmissive substrate to form the HC layer of the present invention having the above-described distribution of the specific low refractive index fine particles, it is assumed that the adhesion to the light-transmissive substrate is excellent. do.

It is a schematic diagram which shows an example of the process of simultaneously apply | coating the curable resin composition for 1st and 2nd HC layers in the manufacturing method of the optical film which concerns on this invention.

The curable resin composition 60 for the first hard coat layer and the curable resin composition 70 for the second hard coat layer were respectively formed from the slits 51 and 52 of the die coater head 40 on the light transmissive substrate 10. Simultaneously apply | coat the intermediate | middle layer application so that the curable resin composition for hard coat layers may be located in the side, and let it be the coating film 61 of the curable resin composition for hard coat layers, and the coating film 71 of the curable resin composition for hard coat layers. In FIG. 3, the curable resin composition for the first hard coat layer and the curable resin composition for the second hard coat layer are integrally formed to form a hard coat layer. However, the two kinds of compositions or the coating films thereof are used for simplicity of explanation. Color classification is described.

Hereinafter, the light transmissive substrate and the first composition and the second composition prepared in the steps (i) and (ii) will be described.

(Light-transmitting substrate)

The light transmissive base material of the present invention is not particularly limited as long as it satisfies the physical properties that can be used as the light transmissive base material of the optical film. The triacetyl cellulose, polyethylene terephthalate, or cycloolefin used in conventionally known hard coat films and optical films is not limited. A polymer etc. can be selected suitably and used.

The average light transmittance of the light-transmitting base material in the visible light region of 380 to 780 nm is preferably 50% or more, more preferably 70% or more, particularly preferably 85% or more. In addition, the measurement of the light transmittance uses the value measured in room temperature and air | atmosphere using the ultraviolet visible spectrophotometer (for example, UV-3100PC by Shimadzu Corporation).

Moreover, surface treatment, such as forming a saponification process and a primer layer, may be given to a transparent base material. In addition, additives, such as an antistatic agent, may be added to a light transmissive base material.

The thickness of a light transmissive base material is not specifically limited, Usually, it is about 20 micrometers-300 micrometers, Preferably it is 40 micrometers-200 micrometers.

(Curable resin composition for first hard coat layer)

The curable resin composition for a 1st hard-coat layer contains the 1st resin and 1st solvent which have reactivity, and also contains the low refractive index microparticles | fine-particles and low refractive index resin, or contains the low refractive index resin, and the mass of the said 1st resin It is 5.0 mass% or less with respect to, and a viscosity micrometer 1 is 5 mPa * s or more.

Even if the first composition does not contain the low refractive index fine particles and the low refractive index resin or contains the low refractive index resin, the second composition having 5.0 mass% or less, the specific viscosity, and will be described later is low relative to the mass of the first resin. The first composition and the second composition are cured by simultaneously applying the two kinds of compositions adjacent to each other such that the refractive index component is included, and the first composition is positioned on the light transmissive substrate side rather than the second composition. In forming the layer, in the film thickness direction of the HC layer, a low refractive index component is gradually decreased from the interface side opposite to the light transmissive substrate to the light transmissive substrate side, and the low refractive index component is a low refractive index fine particle. In the case of, low refractive index fine particles are distributed as shown in FIG. 1.

The viscosity mu 1 of a 1st composition is 3 mPa * s or more and 10 mPa * s or more from the point which suppresses mixing with the 2nd composition mentioned later suitably. 95 mPa * s or less are preferable, as for the said viscosity (micrometer), from a viewpoint of improving coating property, 50 mPa * s or less are more preferable, 30 mPa * s or less are especially preferable. The value obtained by subtracting μ1 from the viscosity μ2 of the second composition (hereinafter may be simply referred to as "viscosity difference") is 30 mPa · s or less. It is preferable that it is 15 mPa * s or less from a viewpoint of the suppression of mixing and the planar shape formed, and, as for the difference of viscosity, it is more preferable that it is 10 mPa * s or less. In addition, it is preferable that (micro) 2 is larger than (micro) 1 from the viewpoint of applicability | paintability as for the viscosity (micro) 1 of a 1st composition, and the viscosity (micro2) of a 2nd composition.

In addition, the viscosity of a 1st composition and the 2nd composition mentioned later uses the brand name MCR301 made from Anton Paar, for example, a measurement jig is PP50, a measurement temperature is 25 degreeC, and a shear rate is 10000 [ The composition to be measured can be added dropwise to the appropriate amount stages under the conditions of 1 / s] and measured.

Even if the 1st composition does not contain low refractive index microparticles | fine-particles and low refractive index resin, or contains low refractive index resin, it is 5.0 mass% or less with respect to the mass of the said 1st resin. It is preferable that such a low refractive index component exist only at the interface on the side opposite to the light transmissive substrate of the HC layer and in the vicinity thereof from the viewpoint of exhibiting antireflection performance. If the low refractive index component exists uniformly in the whole HC layer, there exists a possibility that the antireflection performance of an optical film may not fully be expressed, and the hardness of HC layer may not be fully expressed. On the other hand, the 2nd composition mentioned later has a function which distributes a low refractive index component in the said interface and the area | region near it. Even if the low refractive index resin is contained in a 1st composition, sufficient antireflection performance will be acquired in an optical film as it is said quantity. It is preferable that the quantity of the low refractive index resin contained in a 1st composition is 1 mass% or less with respect to the mass of a 1st resin.

(First resin)

1st resin is a component which has reactivity, hardens | cures, and turns into a matrix of HC layer. 1st resin has superposition | polymerization thru | or crosslinking reactivity with 1st resins and 2nd resin mentioned later by light irradiation or a heating. The first resin may be a photocurable resin that is cured by light irradiation such as ultraviolet rays, or may be a thermosetting resin that is cured by heating.

When 1st resin is photocurable resin, it is preferable that 1st resin has a polymerizable unsaturated group, and it is more preferable to have an ionizing radiation curable unsaturated group. As the specific example, ethylenically unsaturated bonds, such as a (meth) acryloyl group, a vinyl group, an allyl group, an epoxy group, etc. are mentioned.

When 1st resin is thermosetting resin, what has a hydroxyl group, a carboxyl group, an amino group, an epoxy group, glycidyl group, an isocyanate group, an alkoxyl group etc. is mentioned as 1st resin, for example.

It is preferable to have 2 or more reactive groups in 1 molecule, and, as for 1st resin, to increase the hardness of HC layer by crosslinking reaction, it is more preferable to have 3 or more.

As the first resin as the photocurable resin, a photocurable resin that is a matrix of a conventionally known HC layer may be used. For example, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and the like. Polyfunctional monomers of are preferably used.

As a 1st resin as a thermosetting resin, the compound which has an epoxy group, and the binder epoxy compound of Unexamined-Japanese-Patent No. 2006-106503 can be used, for example. Moreover, the thermosetting resin of Unexamined-Japanese-Patent No. 2008-165041 can be used.

From the viewpoint of easily adjusting the viscosity μ1 of the first composition, the molecular weight of the first resin is preferably 500 or more, and more preferably greater than 1000. In addition, it is preferable that the upper limit of the molecular weight of 1st resin is 150000 or less, It is more preferable that it is 50000 or less, It is especially preferable that it is 20000 or less from a viewpoint which is easy to adjust the viscosity (micro) 1 of a 1st composition. When the molecular weight of the first resin is within this range, the low refractive index fine particles and the low refractive index resin contained in the second composition described later are suppressed from being uniformly dispersed in the entire HC layer, and the opposite side to the light transmissive substrate of the HC layer It is easy to exist much in an interface side.

As resin with a molecular weight larger than 1000, for example, the polyalkylene oxide chain containing polymer D of patent document 1, and brand name beam set DK1 of Arakawa Chemical Industries, Ltd. make, Shin-Nakamura Chemical Industries, Ltd. make The brand name NH oligo U-15HA which is a UV curable urethane acrylate oligomer, and the brand name UV-1700B by Nippon Kosei Chemical Industries, Ltd. are mentioned preferably.

It is preferable to contain resin whose molecular weight is 1000 or less in a 1st resin from a viewpoint of suppressing generation | occurrence | production of the interference fringe at the interface of HC layer and a base material. As such a resin with a molecular weight of 1000 or less, the above-mentioned PETA and DPHA are mentioned preferably.

When using together resin whose molecular weight is 1000 or less and resin other than it, ie, resin whose molecular weight is larger than 1000, as 1st resin, content of resin of molecular weight 1000 or less should just be adjusted suitably according to desired viscosity, etc. It is preferable that content of resin is 50-100 mass% with respect to the total mass of 1st resin.

In addition, it is preferable that the molecular weight of 1st resin is 5000 or less from a viewpoint of the hardness of HC layer.

In addition, as 1st resin, you may use the binder C of patent document 1, for example. As a commercial item of the said binder C, the brand name AH-600, AT-600, UA-306H by Kyoesha Chemical Co., Ltd. which is a commercial item of the urethane acrylate which has a weight average molecular weight less than 10000 and has two or more polymerizable unsaturated groups Nippon Kosei Kagaku Kogyo Co., Ltd. product name UV-3000B, UV-3200B, UV-6300B, UV-6330B, UV-7000B including UA-306T, UA-306I, etc. Product name M-6 made by beam set 500 series (502H, 504H, 550B, etc.), brand name U-6HA, UA-32P, U-324A, product made by Shin-Nakamura Kagaku Kogyo Co., Ltd. 9050 etc. are mentioned.

What is necessary is just to adjust content of 1st resin suitably, and 40-90 mass% is preferable with respect to the total solid of a 1st composition, More preferably, it is 50-80 mass%.

1st resin may be used individually by 1 type, and may be used in combination of 2 or more type. In addition, 1st resin may be same or different from 2nd resin contained in the 2nd composition mentioned later, a basic skeleton, the kind of functional group, the number of functional groups, or molecular weight.

(First solvent)

The first solvent has the function of adjusting the viscosity by dissolving or dispersing the same solid content as the first resin in the first composition.

As a 1st solvent, 1 type, or 2 or more types can be used from the solvent conventionally used for the composition for hard-coat layers. For example, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), toluene and the like, alcohols, ketones, esters, halogenated hydrocarbons, aromatic hydrocarbons, and the like described in JP-A-2005-316428 Ethers; and the like. As the first solvent, for example, ethers such as tetrahydrofuran, 1,4-dioxane, dioxolane and diisopropyl ether and glycols such as methyl glycol, propylene glycol monomethyl ether (PGME) and methyl glycol acetate And the like can be used.

From the viewpoint of adjusting (highing) the viscosity of the first composition, the first solvent is preferably high in viscosity, preferably 1 mP · s or more, and more preferably 2 mP · s or more. As a solvent for raising the viscosity of such a 1st composition, propylene glycol monomethyl ether (PGME) etc. are preferable, for example.

Further, by appropriately selecting the kind of the first solvent and the kind of the light transmissive substrate, the first solvent also has an effect of infiltrating a part of the first resin into the light transmissive substrate.

In the present invention, by using (or using in combination) a solvent (penetrating solvent) that is permeable to the light transmissive substrate, the first resin easily penetrates into the substrate and suppresses the occurrence of interference fringes, and the adhesiveness can also be enhanced.

In addition, in this invention, permeability means the meaning including the concept which swells or wets a transparent base material other than the property which permeates with respect to a transparent base material.

Specific examples of the permeable solvent include ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as methyl acetate, ethyl acetate and butyl acetate, halogenated hydrocarbons and phenols.

The solvent used when a light transmissive base material is triacetyl cellulose (TAC), and the solvent used when a light transmissive base material is polyethylene terephthalate (PET) can mention the solvent of Unexamined-Japanese-Patent No. 2005-316428. have.

In particular, the solvent used when the light transmissive substrate is triacetyl cellulose (TAC) is preferably methyl acetate, ethyl acetate, butyl acetate and methyl ethyl ketone.

The first solvent may be the same as or different from the second solvent contained in the second composition described later.

In a 1st composition, it is preferable that the ratio of the mass of 1st resin with respect to the mass of a 1st solvent is 100-400 mass% in the point which distributes many low refractive index components in the HC layer on the opposite side to a light transmissive base material. . In addition, at this time, in the 2nd composition mentioned later, the ratio of the total mass of the low refractive index component and 2nd resin with respect to the mass of a 2nd solvent is 100-400 mass%.

(Other components of curable resin composition for 1st hard-coat layer)

In addition to the above components, the first composition may further include a polymerization initiator, an antistatic agent, a thickener, a reactive or non-reactive leveling agent, and the like for the purpose of providing functionality.

(Polymerization initiator)

You may use suitably selecting a radical, a cationic polymerization initiator, etc. as needed. These polymerization initiators are decomposed by light irradiation and / or heating to generate radicals or cations to advance radical polymerization and cationic polymerization. For example, Irgacure 184 (1-hydroxy cyclohexyl phenyl- ketone) by Ciba Japan Co., Ltd. is mentioned as a radical polymerization initiator.

When using photocationic polymerizable 1st resin like 1st resin containing an epoxy group, the cation polymerization initiator of Unexamined-Japanese-Patent No. 2010-107823 can be used as needed, for example.

When using a polymerization initiator, it is preferable to use that content at 1-10 mass% with respect to the total solid of a 1st composition.

(Antistatic agent)

As the antistatic agent, a conventionally known antistatic agent can be used, and for example, fine particles such as cationic antistatic agents such as quaternary ammonium salts described in JP-A-2007-264221 and fine particles such as tin-doped indium oxide (ITO) Can be used.

When using an antistatic agent, it is preferable to use the content at 30-60 mass% with respect to the total solid of a 1st composition.

(Thickener)

A thickener may be contained in the 1st composition for the purpose of adjustment of a viscosity.

As the thickener, a conventionally known thickener can be used, and for example, a polyetherdialkyl such as protein-based such as casein and casein salt, polyvinyl alcohol, aliphatic amide, acrylic copolymer, polyvinylpyrrolidone, sodium polyacrylate, etc. Organic thickeners such as esters, partial esters of vinyl methyl ether-maleic anhydride copolymers, and acetylene glycols; In addition, inorganic thickeners, such as micro silica, kaolin bentonite, and talc, are mentioned.

The organic thickener and the inorganic thickener may be used alone, or may be used in combination of two or more thereof.

When using a thickener, it is preferable to use the content at 0.1-10 mass% with respect to the total solid of a 1st composition.

(Leveling agent)

The leveling agent has an action of imparting coating stability, slipperiness, antifouling or scratch resistance to the HC surface.

As a leveling agent, leveling agents, such as a fluorine type, a silicone type, and an acryl type, which are used for the conventionally well-known antireflection film, can be used. For example, a fluorine-based leveling agent that does not have an ionizing radiation curable group such as DIC Corporation Megapack series (MCF350-5), and an ionizing radiation curable group such as X22-163A manufactured by Shin-Etsu Chemical Co., Ltd. All the silicone leveling agent which has can be used.

As content in the case of using a leveling agent, when it is a fluorine-type leveling agent, it is preferable to use at 5.0 mass% or less with respect to the mass of 1st resin, and to use it at 0.1-3.0 mass%, and when it is a leveling agent other than fluorine-type, It is preferable to use at 0.5-10 mass% with respect to the mass of 1st resin.

Moreover, it is preferable that content of a leveling agent is 5.0 mass% or less with respect to the total mass of solid content of a 1st composition and a 2nd composition from a viewpoint of the hardness of HC layer.

A 1st composition is normally manufactured by mixing and disperse | distributing a polymerization initiator etc. which are contained as needed in a 1st solvent other than a 1st resin according to a general manufacturing method. A paint shaker, a bead mill, etc. can be used for mixed dispersion.

(Curable resin composition for second hard coat layer)

The curable resin composition for 2nd hard-coat layers used in the manufacturing method of the optical film which concerns on this invention is 1 or more types of low refractive index components chosen from the group which consists of low refractive index microparticles and a low refractive index resin with an average particle diameter of 10-300 nm, and reactivity It contains the 2nd resin which has the 2nd solvent, and the viscosity difference is 5 mPa * s or more, and the difference of viscosity is 30 mPa * s or less.

The second composition includes the low refractive index component, has the specific viscosity, and the two compositions are simultaneously applied simultaneously so that the first composition is located on the light transmissive substrate side rather than the second composition, whereby the first composition and When the second composition is cured to form the HC layer, in the film thickness direction of the HC layer, a distribution in which the low refractive index component gradually decreases from the interface side on the opposite side to the light transmissive substrate to the light transmissive substrate side is taken. When the low refractive index component is low refractive index fine particles, low refractive index fine particles are distributed as shown in FIG. 1.

Viscosity (micro) 2 of the 2nd composition used in the manufacturing method of the optical film which concerns on this invention is 5 mPa * s or more in the point which suppresses mixing with the said 1st composition suitably, It is preferable that it is 10 mPa * s or more. The viscosity µ2 is preferably 100 mPa · s or less, more preferably 50 mPa · s or less, and particularly preferably 30 mPa · s or less from the viewpoint of increasing the coating workability. In addition, it is preferable that (micro) 2 is larger than (micro) 1 from the viewpoint of applicability | paintability as for the viscosity (micro) 1 of a 1st composition, and the viscosity (micro2) of a 2nd composition.

(Low refractive index fine particles)

The low refractive index microparticles | fine-particles used in the manufacturing method of the 1st optical film which concerns on this invention provide antireflective property to the optical film of this invention by existing in many on the interface side on the opposite side to the light transmissive base material of HC layer. In addition to the low refractive index fine particles, the low refractive index resin described later may be used together.

Low refractive index microparticles | fine-particles point out that refractive index is 1.20-1.45.

As the low refractive fine particles, particles which have been used in a conventionally known low refractive index layer can be used. For example, hollow silica fine particles described in Patent Document 2, LiF (refractive index 1.39), MgF ₂ (magnesium fluoride, refractive index 1.38), AlF ₃ (refractive index: 1.38), Na ₃ AlF ₆ may be (cryolite, refractive index 1.33) and ₃ NaMgF the metal fluoride fine particles such as (refractive index 1.36).

Moreover, the low refractive index microparticles | fine-particles may be coat | covered with the organic component which has a polymerizable unsaturated group or a thermosetting group so that the surface may be crosslinked-reacted with a 2nd resin or said 1st resin. As a coating method, the manufacturing method of the reactive inorganic fine particles of Unexamined-Japanese-Patent No. 2008-165040 can be used.

The average particle diameter of low refractive index microparticles | fine-particles is 300 nm or less from the point which prevents haze rise of HC layer. In the case where the low refractive index fine particles are hollow silica fine particles, a void is required so that the average particle size is 10 nm or more from the viewpoint of expressing the effect of lowering the refractive index.

The average particle diameter of the low refractive index fine particles is preferably 10 to 100 nm, more preferably 30 to 100 nm.

What is necessary is just to adjust content of the low refractive index microparticles | fine-particles, and to use, 50-90 mass% is preferable with respect to the total mass with the 2nd resin contained in a 2nd composition, More preferably, it is 65-90 mass%.

(Low refractive index resin)

Low refractive index resin refers to resin whose refractive index after film forming of a coating film is 1.30-1.45. In addition to the low refractive index resin, the low refractive index fine particles may be used together.

In addition, since the low refractive index resin is a component that can become part of the matrix of the HC layer after the film formation of the coating film, the low refractive index resin may also be used as the second resin described later.

As the low refractive index resin, a fluorine-containing resin having a reactive group such as a conventionally known photocurable group or thermosetting group, a fluorine-containing resin not having a reactive group, or the like can be used.

Examples of the fluorine-containing resin having a photocurable group include vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-dioxol, and the like. Fluoroolefins are mentioned.

In addition, as a fluorine-containing resin which has a photocurable group, 2,2,2- trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (purple) Fluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (Meth) acrylate compounds such as (meth) acrylate, α-trifluoromethacrylate methyl, and α-trifluoromethacrylate ethyl; fluorine having 1 to 14 carbon atoms having at least three fluorine atoms in one molecule A fluorine-containing polyfunctional (meth) acrylic acid ester compound etc. which have a fluoroalkyl group, a fluorocycloalkyl group, or a fluoroalkylene group, and at least 2 (meth) acryloyloxy group are mentioned.

As the fluorine-containing resin having a thermosetting group, for example, 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer, fluoroethylene-hydrocarbon-based vinyl ether copolymer and epoxy resin, polyurethane resin, cellulose resin, phenol resin and Fluorine-modified products, such as polyimide resin, etc. can be used.

In addition, you may use the polymer, copolymer, and silicone containing vinylidene fluoride copolymer of the polymeric compound containing the fluorine atom of Unexamined-Japanese-Patent No. 2010-122603.

Although the molecular weight of the low refractive index resin is not particularly limited and can be appropriately selected, 500 to 5000 are preferable from the viewpoint of adjusting the viscosity of the second composition.

Although content of the low refractive index resin contained in a 2nd composition may be adjusted suitably, when low refractive index resin also serves as 2nd resin mentioned later, it is preferable that it is 70-100 mass% with respect to the total solid of a 2nd composition.

(2nd resin)

The second resin is a component that is reactive and cures to form a matrix of the HC layer. 2nd resin has superposition | polymerization thru | or crosslinking reactivity with 2nd resins and said 1st resin by light irradiation or a heating.

The second resin may be a photocurable resin that is cured by light irradiation such as ultraviolet rays, or may be a thermosetting resin that is cured by heating. When 2nd resin is photocurable resin, it is preferable that a 2nd resin has a polymerizable unsaturated group, and it is more preferable to have an ionizing radiation curable unsaturated group. As the specific example, ethylenically unsaturated bonds, such as a (meth) acryloyl group, a vinyl group, an allyl group, an epoxy group, etc. are mentioned.

When 2nd resin is a thermosetting resin, as a thermosetting group which a 2nd resin has, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, glycidyl group, an isocyanate group, an alkoxyl group, etc. are mentioned, for example.

From the viewpoint of increasing the hardness of the HC layer by the crosslinking reaction, the second resin preferably has two or more curable groups in one molecule, and more preferably has three or more.

As 2nd resin, the thing illustrated by the said 1st resin can be used.

What is necessary is just to adjust content of 2nd resin suitably, and 60 mass% or less is preferable with respect to the total solid of a 2nd composition. In addition, when 2nd resin also serves as a low refractive index resin, 100 mass% or less may be sufficient with respect to the total solid of a 2nd composition.

2nd resin may be used individually by 1 type, and may be used in combination of 2 or more type.

(Second solvent)

The second solvent has a function of adjusting the viscosity by dissolving or dispersing solid content such as the low refractive index fine particles and the second resin in the second composition. As a 2nd solvent, the thing illustrated by the said 1st solvent can be used.

(Other components of curable resin composition for 2nd hard-coat layers)

The second composition may further contain a polymerization initiator, an antistatic agent, a thickener, an antifouling agent, a reactive or non-reactive leveling agent, and the like, in addition to the above components for the purpose of imparting functionality.

(Polymerization initiator)

The polymerization initiator can use what was illustrated by the said 1st composition.

When using a polymerization initiator, it is preferable to use the content at 1-5 mass% with respect to the total solid of a 2nd composition.

(Antistatic agent)

The antistatic agent can use what was illustrated by the said 1st composition.

When using an antistatic agent, it is preferable to use the content at 30-60 mass% with respect to the total solid of a 2nd composition.

(Thickener)

Thickeners can be used as exemplified in the first composition.

As content of a thickener, it is preferable to use at 0.1-10 mass% with respect to the total solid of a 2nd composition.

(Antifouling agent)

An antifouling agent may prevent contamination of the outermost surface of the optical film and may impart scratch resistance to the HC layer. The antifouling agent may be included in both the first composition and the second composition. From the viewpoint of effectively expressing the antifouling property at a small content, the antifouling agent is preferably contained only in the second composition.

As the antifouling agent, a conventionally known antifouling agent (antifouling agent) such as a fluorine compound or a silicon compound may be used.

As an antifouling agent, the antifouling agent of Unexamined-Japanese-Patent No. 2007-264279 is mentioned, for example.

It is also preferable to use a commercially available antifouling agent. As such a commercially available antifouling agent (non-reactive), Megapack series manufactured by DIC Corporation, for example, Toshiba Corporation such as trade names MCF350-5, F445, F455, F178, F470, F475, F479, F477, TF1025, F478, and F178K. And TSF series manufactured by Silicon Corporation, X-22 series manufactured by Shin-Etsu Chemical Co., Ltd., KF series, and Silaplane series manufactured by Thixo Corporation.

As a commercially available antifouling agent (reactivity), the brand name SUA1900L10 and brand name SUA1900L6 made by Shin-Nakamura Chemical Industries, Ltd., brand name Ebecryl 350, brand name Ebecryl 1360 and brand name KRM7039, made by Daicel UCB Co., Ltd. UT3971 made by Kagaku Kogyo Co., Ltd. brand name dispenser TF3001, brand name dispenser TF3000 and brand name dispenser TF3028, brand name light pro-coat AFC3000 made by Kyoeisha Chemical Co., Ltd., Shin-Etsu Chemical Co., Ltd. The brand name KNS5300 by the Co., Ltd., brand name UVHC1105 and UVHC8550 by GE Toshiba Silicone Co., Ltd., and the brand name ACS-1122 by Nippon Paint Co., Ltd. are mentioned.

(Leveling agent)

Leveling agents may be used as exemplified in the first composition.

Although a leveling agent may be contained in any of a 1st composition and a 2nd composition, it is preferable to be contained only in a 2nd composition from a viewpoint of expressing the function of a leveling agent efficiently.

As content in the case of using a leveling agent, when it is a fluorine-type leveling agent, it is preferable to use at 5.0 mass% or less with respect to the mass of a 2nd resin, and to use it at 0.1-3.0 mass%, and when it is a leveling agent other than fluorine-type, It is preferable to use at 0.5-10 mass% with respect to the mass of 2nd resin.

The manufacturing method of a 2nd composition can use the method illustrated by the said 1st composition.

(Other Functional Layer Composition)

In the manufacturing method of the optical film which concerns on this invention, what is necessary is just to apply | coat simultaneously at least the said 1st and 2nd composition to one surface side of a light transmissive base material in the said (iii) simultaneous coating process, and the required performance of an optical film In order to form another functional layer at timely, you may prepare another composition for functional layers.

As another functional layer, an antistatic layer and an antifouling layer are mentioned, for example.

In addition, as described later, the other functional layer composition can be appropriately set in accordance with the function as long as the composition is applied adjacently so that the first and second compositions are positioned from the light-transmitting substrate side.

(Iii) In the process of simultaneously applying a 1st composition and a 2nd composition of the manufacturing method of the optical film which concerns on this invention, the method of simultaneously apply | coating the said 1st and 2nd composition will not be restrict | limited especially if it can apply | coat simultaneously. Instead, a conventionally known method can be used. For example, a method using an extruded die coater as shown in FIG. 3 can be mentioned.

(Iii) In the process of simultaneously applying a 1st composition and a 2nd composition of the manufacturing method of an optical film, when the wet film thickness of the coating film of a 1st composition is T1 and the wet film thickness of the coating film of a 2nd composition is T2. , T2 / T1 is 0.01 to 1, in the film thickness direction of the HC layer, more low refractive index components exist on the interface side on the side opposite to the light-transmissive substrate of the HC layer than on the light-transmissive substrate side, and on the light-transmissive substrate It is distributed so that the abundance of the low refractive index component becomes smaller, and the said low refractive index component gradually decreases from the interface on the opposite side to the light transmissive substrate side to the light transmissive substrate side, and the light transmittance in the film thickness direction of the hard coat layer. A distribution in which 70 to 100% of the total amount of the low refractive index component is present in an area from the interface opposite to the substrate to 70% of the dry film thickness of the hard coat layer. Possible, it is efficiently preferable in view to increase the anti-reflective property of the optical film. Here, a wet film thickness is the thickness of the coating film of the state before the solvent in the composition immediately after application | coating volatilizes, and is calculated | required from (volume / coating area of the composition apply | coated on a light transmissive base material).

In addition, when application | coating of a 1st and 2nd composition is performed using the die coater head as shown in FIG. 3, the coater gap 80 which is the distance of the die coater head 40 and the transparent resin base material 10, and When the thickness 90 of the sum total of the coating film of the 1st and 2nd composition when apply | coating multilayered on the transparent resin base material 10 simultaneously is related to the relationship of a coater gap 80 <(double of thickness 90) It is desirable to have. By simultaneously applying the multilayers while maintaining such a relationship, the coating beads formed between the transparent resin substrate 10 and the die coater head 40 are stabilized. In particular, the coating beads tend to become unstable as the layer formed by coating becomes thinner, causing unevenness and streaks on the coated surface, thereby deteriorating the appearance, but maintaining the relationship between the coater gap 80 and the thickness 90. This makes it easy to stabilize the coating beads. In addition, application | coating bead means the liquid pool produced between an application | coating apparatus and a base material.

The said other functional layer composition may be apply | coated simultaneously with a 1st and 2nd composition, and may be apply | coated separately from a 1st and 2nd composition. When apply | coating simultaneously, just apply | coating adjacently so that a 1st and 2nd composition may be located from the light transmissive base material side, a coating position can be suitably set according to the function. For example, when applying the composition for antistatic layers together with a 1st and 2nd composition simultaneously, it is an upstream side of the conveyance direction 140 of a light transmissive base material rather than the slit 51 of the die head of FIG. In the present invention, a third slit (not shown) may be provided on the left side of the slit 51, and the antistatic layer composition and the first and second compositions may be simultaneously applied. In addition, when apply | coating antistatic layer composition, a 1st, 2nd composition, and an antifouling layer composition simultaneously, for example, the 3rd slit for apply | coating the antistatic layer composition to the left side of the slit 51 in FIG. What is necessary is just to provide the 4th slit (not shown) for apply | coating the composition for antifouling layers on the right side of the slit 52 (not shown), and apply | coating the said 4 types of compositions simultaneously.

As a drying method of a (iv) process, the pressure reduction drying or heat drying, the method of combining these drying, etc. are mentioned, for example. Further, in the case of drying at normal pressure, it is preferable to dry at 30 to 110 ° C.

In the present invention, preliminary curing is not performed before the step (iv), that is, before the coating film is dried.

For example, when methyl isobutyl ketone is used as the first or second solvent, usually 20 seconds to 3 minutes at a temperature within the range of room temperature to 80 ° C, preferably 40 ° C to 70 ° C, preferably 30 Drying is performed in a time of about 1 to 1 minute.

In the present invention, the drying of the step (iv) means that the curing of the layer is not sufficient as a product even if the drying is performed (for example, the pencil hardness test specified in JIS K5600-5-4 (1999)). (Meaning less than the hardness "H" at 4.9N load), the heating performed after drying when the first resin or the second resin contains a thermosetting resin, curing the layer by performing the heating It means processing at the temperature of the grade (hardness "H" or more by the said pencil hardness test) to become enough as a product.

As the light irradiation method of the step (iv), ultraviolet rays, visible light, electron beams or ionizing radiation are mainly used. In the case of ultraviolet curing, ultraviolet rays emitted from light such as ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc or metal halide lamp are used. The irradiation amount of an energy source is 50-300 mJ / cm <^2> as an integrated exposure amount in an ultraviolet-ray wavelength 365nm.

In this invention, preliminary hardening is not performed but light irradiation and heating which harden | cure a coating film (main hardening) are performed after drying of a coating film. Thereby, in the film thickness direction of HC layer, the low refractive index component contained in a 2nd composition exists more in the interface side on the opposite side to the light transmissive base material of HC layer than the light transmissive base material side, and the light transmissive base material side It is distributed so that the amount of low refractive index component is decreased, and the low refractive index component gradually decreases from the interface on the opposite side to the light transmissive substrate to the light transmissive substrate side, and the refractive index difference between the low refractive index component and the resin of the HC layer in the HC layer. The optical film which suppresses generation | occurrence | production of interference fringes by this, and generation | occurrence | production of interference fringes in the interface of HC layer and a base material, and is excellent in visibility is obtained.

In addition, since the coating film is dried without preliminary curing, and the coating film is cured by subsequent light irradiation or heating, the contact with the HC layer, the light-transmissive substrate, or the light-transmissive substrate side of the HC layer is in comparison with the case of pre-curing and curing. Adhesion with a layer can be improved.

Moreover, since it is not necessary to perform precure, it is excellent also in productivity compared with the case where it performs the 2nd light irradiation of precure and this hardening, and hardens | cures it.

(Optical film)

The optical film which concerns on this invention is obtained by the said manufacturing method, and as shown in FIG. 1, HC layer 20 is formed in at least one surface side of the transparent base material 10. As shown in FIG.

The optical film of this invention is manufactured by the said manufacturing method, and the low refractive index microparticles | fine-particles and / or low refractive index resin which are contained in a 2nd composition are in the film thickness direction of HC layer, on the opposite side to the light transmissive base material of HC layer. It exists more in an interface side than a light transmissive base material side, and it exists so that it exists in the light transmissive base material side so that it may become small, and it exists in the HC layer by the refractive index difference of the low refractive index microparticles | fine-particles and / or low refractive index resin, and resin of HC layer. The optical film which suppresses generation | occurrence | production of interference fringes and generation | occurrence | production of interference fringes at the interface of HC layer and a base material, and is excellent in visibility is obtained.

In addition, since the coating film is dried without preliminary curing and subsequently cured by light irradiation or heating, the conventional low refractive index layer and the conventional low refractive index layer are compared with the case of preliminary curing, followed by drying, light irradiation or heating. The surface does not exhibit the clear layer interface as in the case where the HC layer is formed by sequential middle layer coating or the case of simultaneous coating as in Patent Document 2, and also has an antireflection function, and has no haze, total light transmittance and streaks Interference between the hard coat layer and the base material is maintained by suppressing the occurrence of interference fringes between the layers while maintaining the shape, improving the adhesion, and increasing the ratio of the hard coat composition having the same refractive index as that of the base material in the vicinity of the base material. It suppresses generation | occurrence | production of a streak and is excellent in adhesiveness.

The optical film of this invention may apply | coat another composition for functional layers, and may form another functional layer as demonstrated in the said manufacturing method, For example, the composition for antistatic layers is provided to the light transmissive base material side of a 1st composition. When apply | coating and forming an antistatic layer, it becomes a layer structure called antistatic layer 140 and HC layer 20 from the light transmissive base material 10 side as shown in FIG.

In addition, as shown in FIG. 5, you may form the antifouling layer 150 in the surface on the opposite side to the light transmissive base material of HC layer.

The dry film thickness (henceforth simply called "film thickness") of HC layer can be adjusted suitably according to the performance calculated | required, for example, it is preferable that it is 1-20 micrometers in film thickness.

What is necessary is just to adjust the film thickness of another functional layer suitably, for example, the film thickness of an antistatic layer is preferable 0.05-5 micrometers, and the film thickness of an antifouling layer is preferable 0.01-10 nm.

The optical film of the present invention can adjust the reflectance by appropriately adjusting the type and content of the low refractive index fine particles and the low refractive index resin of the second composition according to the required performance, but the reflectance is preferably 1 to 3.75 with respect to the incident light. And it is more preferable that it is 1-3.4.

The reflectance was measured by using the Nippon Bunko Co., Ltd. product name V7100 ultraviolet visible spectrophotometer and the Nippon Bunco Co. product name VAR-7010 absolute reflectance measuring device, the angle of incidence was 5 °, the polarizer was N-polarized, and the wavelength range was measured. A black tape is bonded to the TAC base material side of an optical film as 380-780 nm, it is installed in an apparatus, and it measures. In addition, let the reflectance be the average value of the measurement result calculated | required in the measurement wavelength range.

Although the haze of the optical film of this invention can be suitably adjusted according to the performance calculated | required, it is preferable that it is 0.1 to 1.0%, and it is more preferable that it is 0.1 to 0.4%.

The haze value can be measured by a reflection / transmittance meter HM-150 (manufactured by Murakami Shikisai Kijutsu Co., Ltd.) in accordance with JIS K7136.

In suitable embodiment of the optical film which concerns on this invention, it is an optical film in which the hard-coat layer was formed in the one surface side of a transparent base material, and low refractive index microparticles | fine-particles are a side opposite to the said transparent base material in the film thickness direction of the said hard-coat layer. The amount of the low refractive index fine particles is smaller on the interface side of the light transmissive substrate side than on the light transmissive substrate side, and the low refractive index component is spread from the interface on the opposite side to the light transmissive substrate to the light transmissive substrate side. This gradually decreases, there is no layer interface in the hard coat layer, and the adhesion rate of the checkerboard scale adhesion test with respect to the light transmissive substrate of the hard coat layer may be set to 90 to 100%.

As shown in Fig. 1, by distributing such low refractive index fine particles in the HC layer, it has an antireflection function and suppresses generation of interference fringes between layers while maintaining a haze, total light transmittance, and a surface shape without streaks. In order to improve the adhesiveness and increase the ratio of the hard coat composition having the same refractive index as that of the base material in the vicinity of the base material, the occurrence of interference fringes between the hard coat layer and the base material can be suppressed and the optical film excellent in the adhesiveness Is obtained.

The layer interface in a hard-coat layer means that an interface (boundary) arises in the hardened part of a composition in a layer, as shown in FIG. As a specific example of a layer interface, the boundary of the hardened part of 2 types of compositions shown in FIG. 9 mentioned later is mentioned.

In a preferred embodiment of the optical film according to the present invention, in the film thickness direction of the hard coat layer, in the region from the interface on the side opposite to the light transmissive substrate to 70% of the dry film thickness of the hard coat layer, the low It is also possible that 70 to 100% of the total amount of the refractive index fine particles is present. Thereby, the antireflection property of an optical film can be raised efficiently.

90% or more is preferable and, as for the total light transmittance (tau t) of the optical film of this invention, 92% or more is more preferable.

The total light transmittance of an optical film can be measured with the same measuring device as a haze value according to JISK7361.

(Polarizer)

The polarizing plate which concerns on this invention is provided with the polarizer in the light transmissive base material side opposite to the said hard-coat layer of the said optical film, It is characterized by the above-mentioned.

It is a schematic diagram which shows an example of the laminated constitution of the polarizing plate which concerns on this invention. The polarizing plate 2 illustrated in FIG. 6 includes a polarizer 180 in which the optical film 1 having the HC layer 20 is formed on the transparent substrate 10, the protective film 160, and the polarizing layer 170 are laminated. It has, and the polarizer 180 is provided in the light transmissive base material 10 side opposite to HC layer 20 of the optical film 1.

In addition, the fact that a polarizer is arrange | positioned at the light transmissive base material side opposite to the hard-coat layer of an optical film is not only the case where an optical film and a polarizer are formed separately, but the member which comprises an optical film comprises the polarizer. It also includes the case where it also serves as.

In addition, when using the polarizing plate which concerns on this invention for a display panel, a display panel is normally arrange | positioned at the polarizer side.

In addition, since the optical film mentioned above should be used about an optical film, the description here is abbreviate | omitted. Hereinafter, the other structure in the polarizing plate which concerns on this invention is demonstrated.

(Polarizer)

As a polarizer used for this invention, if it has a predetermined polarization characteristic, it will not specifically limit, Generally, the polarizer used for a liquid crystal display device can be used.

A polarizer will not be specifically limited if it is a form which can maintain predetermined | prescribed polarization characteristic for a long time, For example, it may be comprised only with a polarizing layer, and the thing which the protective film and the polarizing layer were bonded may be sufficient. When the protective film and the polarizing layer are bonded, the protective film may be formed only on one side of the polarizing layer, or the protective film may be formed on both surfaces of the polarizing layer.

As a polarizing layer, the thing which formed the complex of polyvinyl alcohol and iodine is usually used by impregnating iodine in the film which consists of polyvinyl alcohol, and uniaxially stretching this.

Moreover, as a protective film, if the said polarizing layer can be protected and it has desired light transmittance, it will not specifically limit.

As light transmittance of a protective film, it is preferable that the transmittance | permeability in a visible light region is 80% or more, and it is more preferable that it is 90% or more.

In addition, the transmittance | permeability of the said protective film can be measured by JISK7361-1 (test method of the total light transmittance of a plastics-transparent material).

Examples of the resin constituting the protective film include a cellulose derivative, a cycloolefin resin, polymethyl methacrylate, polyvinyl alcohol, polyimide, polyarylate, and polyethylene terephthalate. Among them, it is preferable to use a cellulose derivative or a cycloolefin-based resin.

The protective film may consist of a single layer or may be a laminate of a plurality of layers. In addition, when a protective film is what laminated | stacked several layers, the some layer of the same composition may be laminated | stacked, and the some layer which has another composition may be laminated | stacked.

The thickness of the protective film is not particularly limited as long as the flexibility of the polarizing plate of the present invention can be within a desired range, and the dimensional change of the polarizer can be within a predetermined range by bonding with the polarizing layer. It is preferable to exist in the range of -200 micrometers, It is preferable to exist in the range of 15-150 micrometers especially, and also to exist in the range which is 30-100 micrometers further. When the said thickness is thinner than 5 micrometers, there exists a possibility that the dimensional change of the polarizing plate of this invention may become large. Moreover, when the said thickness is thicker than 200 micrometers, when cutting the polarizing plate of this invention, for example, there exists a possibility that processing waste may increase or abrasion of a cutting blade may accelerate.

The protective film may have a retardation. By using the protective film which has retardation, there exists an advantage that the polarizing plate of this invention can be made to have the viewing angle compensation function of a display panel.

It will not specifically limit, if the protective film is a form which can express desired retardation as a form which has retardation. As such an aspect, the protective film has a structure which consists of a single layer, for example, and contains refractive index anisotropy on the aspect which has retardation by containing the optical characteristic expression agent which expresses retardation, and the protective film which consists of resin mentioned above When the retardation layer containing the compound which has a compound is laminated | stacked, the aspect which has retardation is mentioned. In this invention, any of these forms can be used suitably.

(display)

The display which concerns on this invention is arrange | positioned at the light transmissive base material side opposite to the said hard-coat layer of the said optical film, It is characterized by the above-mentioned.

Examples of the display include LCD, PDP, ELD (organic EL, inorganic EL), CRT, and the like.

The display consists of a display panel of a viewer side member of the display and a back side member including a drive unit. When explaining a liquid crystal display as an example, a display panel is a member which consists of two glass plates (for example, a color filter board | substrate and an array board | substrate), a polarizing plate, the optical film of this invention, etc. which trapped the liquid crystal material. Taking a liquid crystal display as an example, the back side member is a member including a light source called a backlight, a driving circuit for controlling the LCD, a circuit for controlling the light source, a chassis, and the like. As an example of the layer structure of a liquid crystal display in this case, there exists a backlight part containing a light guide plate, a diffusion film, etc., and is laminated | stacked on the viewer side in order of a polarizing plate, an array substrate, a liquid crystal layer, a color filter substrate, a polarizing plate, and an optical film. .

The PDP which is another example of the said display is provided with the surface glass substrate and the back glass substrate in which discharge gas was enclosed and arrange | positioned facing the said surface glass substrate. When the display is a PDP, the optical film may be provided on the surface of the surface glass substrate or on the front surface plate thereof (glass substrate or film substrate).

The display includes a light emitting element such as zinc sulfide or a diamine material that emits light when a voltage is applied to a glass substrate, and converts an ELD device or an electrical signal that displays the light by controlling the voltage applied to the substrate to light, thereby making the image visible to the human eye. It may be a display such as a CRT that generates. In this case, the optical film is provided on the outermost surface of the ELD device or the CRT or on the surface of the front face plate.

<Examples>

Hereinafter, the present invention will be described more specifically by way of examples. The present invention is not limited by these descriptions.

As low refractive index microparticles | fine-particles, the hollow silica microparticles (brand name through rear DAS (average particle diameter 50nm, MIBK dispersion liquid, 20% of solid content)) by the Nikki Shokubai Kasei Co., Ltd. were used.

The brand name beam set DK1 (weight average molecular weight 20000, 75% of solid content, MIBK solvent) by Arakawa Chemical Industries, Ltd. was used as 1st resin (1).

Nippon Kayaku Co., Ltd. pentaerythritol triacrylate was used as 1st resin (2).

LINC-3A (triacryloyl-heptadecafluorononenyl-pentaerythritol (main component) represented by the following formula (1)) manufactured by Kyoeisha Chemical Co., Ltd. as a low refractive index resin serving as the first resin; A mixture of pentaerythritol triacrylate).

(1)

As a polymerization initiator, the brand name Irgacure (Irg) 184 by Ciba Japan Co., Ltd. was used.

The brand name MCF350-5 (solid content 5%) by DIC Corporation was used as a leveling agent.

MIBK was used as a solvent.

As a light-transmissive base material, the TAC base material and brand name TD80UL (80 micrometers in thickness) made from Fujifilm Co., Ltd. were used.

In addition, the viscosity of a 1st composition and a 2nd composition uses MCR301 made from Anton Parsa, the measurement jig is PP50, the measurement temperature is 25 degreeC, and the shear rate is the composition of a measurement object on 10000 [1 / s] conditions. (Ink) was dripped at the appropriate amount stage and it measured.

The dry film thickness was measured by placing a sample to be measured on glass using a Mitsutoyo trade name DIGIMATIC INDICATOR CODE215-403.

The abbreviations of the respective compounds are as follows.

PETA: pentaerythritol triacrylate

MIBK: methyl isobutyl ketone

IPA: isopropanol

TAC: triacetylcellulose

(Manufacture of curable resin composition for 1st hard-coat layer)

The components of the composition shown below were respectively mix | blended and the curable resin composition 1 and 2 for 1st hard-coat layer, and curable resin composition 1 for 2nd hard-coat layer were manufactured.

(Curable resin composition 1 for 1st hard-coat layer)

Beam set DK1: 64.72 parts by mass (48.54 parts by mass in terms of solids)

Irg184: 1.94 parts by mass

MCF350-5: 0.97 parts by mass (0.05 parts by mass of solid content)

MIBK: 32.36 parts by mass

(Curable resin composition 2 for 1st hard-coat layer)

PETA: 75.49 parts by mass (56.62 parts by mass in terms of solids)

Irg184: 3.02 parts by mass

MCF350-5: 3.02 parts by mass (solid content of 0.15 parts by mass)

MIBK: 18.47 parts by mass

(Curable resin composition 1 for 2nd hard-coat layers)

Through rear DAS: 75.81 (15.16 parts by weight of solids)

Beam set DK1: 13.48 parts by mass (10.11 parts by mass in terms of solid content)

Irg184: 0.61 parts by mass

MCF350-5: 10.11 parts by mass (0.51 parts by mass in terms of solid content)

(Curable resin composition 2 for 2nd hard-coat layers)

Through rear DAS: 83.12 (16.62 parts by weight of solid content)

Beam set DK1: 15.83 parts by mass (solid equivalents 11.87 parts by mass)

Irg184: 0.48 parts by mass

MCF350-5: 0.57 parts by mass (solid content of 0.03 parts by mass)

(Curable resin composition 3 for 2nd hard-coat layers)

Through rear DAS: 73.95 (14.79 parts by mass of solid content)

Beam set DK1: 24.65 parts by mass (18.49 parts by mass in terms of solid content)

Irg184: 0.74 mass parts

MCF350-5: 0.67 parts by mass (solid content of 0.03 parts by mass)

(Curable resin composition 4 for 2nd hard-coat layers)

LINC-3A: 78.63

Irg184: 3.15 parts by mass

MCF350-5: 15.73 parts by mass (0.79 parts by mass in terms of solids)

MIBK: 2.49 parts by mass

(Production of optical film)

(Example 1)

The solvent was distilled off using the said curable resin composition 1 for 1st hard-coat layers, and the curable resin composition 1 for 2nd hard-coat layers using an evaporator, and the viscosity was adjusted to 30 mPa * s, respectively. Subsequently, on a TAC base material (TD80UL) conveyed at the speed of 1 m / min, 2 layer simultaneous application | coating is apply | coated so that curable resin composition 1 for 1st hard-coat layers and curable resin composition 1 for 2nd hard-coat layers may be located from a TAC base material side. It was done. At this time, the wet film thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 1 for 2nd hard-coat layers was 20 micrometers and 10 micrometers, respectively.

Subsequently, the coating film of two-layer co-application is dried at 70 degreeC for 60 second, and a hard-coat layer with a dry film thickness of 10 micrometers is formed by irradiating an ultraviolet-ray to a accumulated light amount of 120 mJ / cm <^2> in nitrogen atmosphere, and hardening a coating film. The optical film was produced.

(Comparative Example 1)

In Example 1, only the curable resin composition 1 for 1st hard-coat layer was apply | coated to 20 micrometers of wet film thickness, and the hard coat layer of 9 micrometers of dry film thickness was formed, without using curable resin composition 1 for 2nd hard-coat layers. Except having done, the optical film was produced like Example 1.

(Comparative Example 2)

In Example 1, only curable resin composition 1 for 2nd hard-coat layers is apply | coated to 20 micrometers of wet film thicknesses, and the hard coat layer of 10 micrometers of dry film thicknesses is formed, without using curable resin composition 1 for 1st hard-coat layers. Except having done, the optical film was produced like Example 1.

(Comparative Example 3)

In Example 1, only the curable resin composition 1 for the first hard coat layer was applied at a wet film thickness of 20 μm, the coating film was dried at 70 ° C. for 60 seconds, and the amount of ultraviolet light accumulated in a nitrogen atmosphere was 120 mJ / cm ² . Irradiate, harden a coating film, and apply | coating only the curable resin composition 1 for 2nd hard-coat layers at 10 micrometers of wet film thickness on this cured film, and drying this coating film at 70 degreeC for 60 second, and integrating an ultraviolet-ray under nitrogen atmosphere. The optical film was produced like Example 1 except having irradiated so that light quantity might be 120mJ / cm <^2> and hardening a coating film and forming the hard-coat layer of 10 micrometers of total dry film thicknesses.

(Example 2)

The said curable resin composition 1 for hard coat layers, and the curable resin composition 2 for 2nd hard coat layers were adjusted to viscosity 10 mPa * s, respectively. Subsequently, on the TAC base material (TD80UL) conveyed at the speed of 20 m / min, 2 layer simultaneous application | coating is apply | coated so that curable resin composition 1 for 1st hard-coat layers and curable resin composition 2 for 2nd hard-coat layers may be located from a TAC base material side. It was done. At this time, the wet film thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 2 for 2nd hard-coat layers was set to 25 micrometers and 5 micrometers, respectively.

Subsequently, the coating film of two-layer co-application is dried at 70 degreeC for 60 second, and a hard-coat layer with a dry film thickness of 11 micrometers is formed by irradiating an ultraviolet-ray to a accumulated light amount of 120 mJ / cm <^2> in nitrogen atmosphere, and hardening a coating film. The optical film was produced.

(Example 3)

In Example 2, the wet-coat thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 2 for 2nd hard-coat layers is set to 25 micrometers and 1 micrometer, respectively, and the hard-coat layer of 8 micrometers of dry film thicknesses Except for forming a film, an optical film was produced in the same manner as in Example 2.

(Example 4)

In Example 2, the wet-coat thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 2 for 2nd hard-coat layers was 18.75 micrometers, 3.75 micrometers, respectively, and the hard-coat layer of 6 micrometers of dry film thicknesses Except for forming a film, an optical film was produced in the same manner as in Example 2.

(Comparative Example 4)

In Example 2, only curable resin composition 1 for 1st hard-coat layer is apply | coated to 20 micrometers of wet film thickness, without using curable resin composition 2 for 2nd hard-coat layer, and the hard-coat layer of 11 micrometers of dry film thickness is formed. Except having done, the optical film was produced similarly to Example 2.

(Comparative Example 5)

In Example 2, only curable resin composition 2 for 2nd hard-coat layers was apply | coated to 10 micrometers of wet film thicknesses, without using the curable resin composition 1 for 1st hard-coat layer, and the hard-coat layer of 5 micrometers of dry film thicknesses was formed. Except having done, the optical film was produced similarly to Example 2.

(Comparative Example 6)

In Example 2, after simultaneous application | coating of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 2 for 2nd hard-coat layers, before drying, ultraviolet-ray is irradiated so that accumulated light amount may be 50 mJ / cm <^2> (preliminary | preliminary). Except having hardened), it carried out similarly to Example 2, and produced the optical film.

(Example 5)

The said curable resin composition 1 for hard coat layers, and the curable resin composition 3 for 2nd hard coat layers were adjusted to viscosity 10 mPa * s, respectively. Subsequently, on the TAC base material (TD80UL) conveyed at the speed of 20 m / min, 2 layer simultaneous application | coating is applied so that the curable resin composition 1 for 1st hard-coat layers and curable resin composition 3 for 2nd hard-coat layers may be located from a TAC base material side. It was done. At this time, the wet film thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 3 for 2nd hard-coat layers was 25 micrometers and 5 micrometers, respectively.

Subsequently, the coating film of two-layer co-application is dried at 70 degreeC for 60 second, and a hard coat layer with a dry film thickness of 9 micrometers is formed by irradiating an ultraviolet-ray to a accumulated light amount of 120 mJ / cm <^2> in nitrogen atmosphere, and hardening a coating film. The optical film was produced.

(Example 6)

In Example 5, the wet-coat thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 3 for 2nd hard-coat layers is set to 25 micrometers and 1 micrometer, respectively, and the hard coat layer of 8 micrometers of dry film thicknesses Except for forming a film, an optical film was produced in the same manner as in Example 5.

(Example 7)

In Example 5, the wet-coat thickness of the coating film of curable resin composition 1 for 1st hard-coat layers, and curable resin composition 3 for 2nd hard-coat layers was 18.75 micrometers and 3.75 micrometers, respectively, and the hard-coat layer of 5 micrometers of dry film thicknesses Except for forming a film, an optical film was produced in the same manner as in Example 5.

(Comparative Example 7)

In Example 5, only the curable resin composition 3 for 2nd hard-coat layers was apply | coated to 10 micrometers of wet film thicknesses, without using the curable resin composition 1 for 1st hard-coat layers, and the hard-coat layer of 5 micrometers of dry film thicknesses was formed. Except having done, the optical film was produced similarly to Example 5.

(Example 8)

The said curable resin composition 2 for 1st hard-coat layers, and the curable resin composition 4 for 2nd hard-coat layers were adjusted to viscosity 30 mPa * s, respectively. Subsequently, on the TAC base material (TD80UL) conveyed at the speed of 1 m / min, two-layer simultaneous application | coating is applied so that the curable resin composition 2 for 1st hard-coat layers and curable resin composition 4 for 2nd hard-coat layers may be located from a TAC base material side. It was done. At this time, the wet film thickness of the coating film of curable resin composition 2 for 1st hard-coat layers, and curable resin composition 4 for 2nd hard-coat layers was 20 micrometers and 10 micrometers, respectively.

Subsequently, the coating film of the two-layer co-application is dried at 25 degreeC for 60 second, and a hard-coat layer with a dry film thickness of 14 micrometers is formed by irradiating an ultraviolet-ray to a accumulated light amount of 120 mJ / cm <^2> in nitrogen atmosphere, and hardening a coating film. And the optical film was produced.

(Example 9)

In Example 8, an optical film was produced in the same manner as in Example 8 except that the drying temperature of the coating film of the two-layer co-application was set to 50 ° C.

(Example 10)

In Example 8, the optical film was produced like Example 8 except having made the drying temperature of the coating film of two layer simultaneous coating into 70 degreeC.

(Example 11)

In Example 8, an optical film was produced in the same manner as in Example 8 except that the drying temperature of the coating film of the two-layer simultaneous coating was set to 100 ° C.

(Example 12)

In Example 10, it carried out similarly to Example 10 except having set the wet film thickness of the coating film of curable resin composition 2 for 1st hard-coat layers, and curable resin composition 4 for 2nd hard-coat layers, respectively to 25 micrometers and 5 micrometers. A film was produced.

(Comparative Example 8)

In Example 10, only the curable resin composition 2 for 1st hard-coat layers was apply | coated to 20 micrometers of wet film thicknesses, without using the curable resin composition 4 for 2nd hard-coat layers, and the hard-coat layer of 9 micrometers of dry film thicknesses was formed. Except what was done, the optical film was produced like Example 10.

(Comparative Example 9)

In Example 10, only the curable resin composition 4 for 2nd hard-coat layers was apply | coated to 10 micrometers of wet film thicknesses, without using the curable resin composition 2 for 1st hard-coat layers, and the hard-coat layer with a dry film thickness of 8 micrometers was formed. Except what was done, the optical film was produced like Example 10.

(Example 13)

In Example 1, the viscosity of curable resin composition 1 for 1st hard-coat layers and curable resin composition 1 for 2nd hard-coat layers is adjusted to 90 mPa * s, respectively, and curable resin composition 1 for 1st hard-coat layers at the time of simultaneous application | coating And the wet film thickness of the coating film of the curable resin composition 3 for 2nd hard-coat layers were set to 25 micrometers and 5 micrometers, respectively, and the optical film was carried out similarly to Example 1 except having formed the hard-coat layer with a dry film thickness of 18 micrometers. Produced.

(Comparative Example 10)

In Example 1, the viscosity of the curable resin composition 1 for 1st hard-coat layers, and the curable resin composition 1 for 2nd hard-coat layers were adjusted to be 4 mPa * s, respectively, and the hard-coat layer with a dry film thickness of 5 micrometers was formed. In the same manner as in Example 1 except for the above, an optical film was produced.

(Comparative Example 11)

In Example 1, the viscosity of the curable resin composition 1 for the first hard coat layer and the curable resin composition 1 for the second hard coat layer was adjusted to 10 mPa · s and 4 mPa · s, respectively, and the hard coat layer having a dry film thickness of 9 μm. Except for forming a film, an optical film was produced in the same manner as in Example 1.

(Comparative Example 12)

In Example 1, the viscosity of the curable resin composition 1 for the first hard coat layer and the curable resin composition 1 for the second hard coat layer was adjusted to be 62 mPa · s and 10 mPa · s, respectively, and the hard coat layer having a dry film thickness of 17 μm. Except for forming a film, an optical film was produced in the same manner as in Example 1.

(Comparative Example 13)

In Example 1, the viscosity of curable resin composition 1 for 1st hard-coat layer, and curable resin composition 1 for 2nd hard-coat layer was adjusted so that it might be set to 10 mPa * s, respectively, and the adjusted two compositions were used in Example 1, The same amount was mixed and the mixed composition was applied on a TAC substrate. At this time, the wet film thickness of the coating film of this mixed composition was 30 micrometers.

Subsequently, the coating film was dried and irradiated with light in the same manner as in Example 1 to form a hard coat layer having a dry film thickness of 10 μm, thereby producing an optical film.

Table 1 shows the types of compositions used in the examples and comparative examples, the wet film thickness, the coating method, the dry film thickness and the drying conditions, and the conveyance speed of the TAC substrate.

(Evaluation of optical film)

About the optical film of the said Example and a comparative example, as shown below, it measured about reflectance, haze (Hz), and total light transmittance. Moreover, about the optical film of the said Example and a comparative example, as shown below, interference fringe was evaluated, respectively. The results are shown in Table 2.

In addition, the cross-sectional photograph of the optical film of Example 1 is shown to FIG. 7 and 8, and the cross-sectional photograph of the optical film of the comparative example 3 is shown in FIG. In addition, the cross-sectional photograph of FIG. 8 enlarges the interface side on the opposite side to the TAC base material of HC layer in the photograph of FIG.

(Measurement of reflectance)

The reflectance was measured using a Nippon Bunko Co., Ltd. brand name V7100 ultraviolet visible spectrophotometer and a Nippon Bunko Co., Ltd. brand name VAR-7010 absolute reflectance measuring device, at an angle of incidence of 5 ° and polarized light with N polarization. The black tape was bonded to the TAC base material side of an optical film with the wavelength range 380-780 nm, it was installed in the apparatus, and it measured. In addition, the average value of the measurement result calculated | required in the measurement wavelength range was made into the reflectance.

(Measurement of haze and total light transmittance)

Haze and total light transmittance were measured with the reflection and transmittance meter HM-150 (made by Murakami Shikisai Kijutsu Co., Ltd.) based on JISK-7136 and JISK7361, respectively.

(Evaluation of interference stripes)

Visual inspection was performed using an interference striation test lamp (Na lamp) manufactured by Funatech Co., Ltd., and evaluated according to the following criteria.

○: almost no generation of interference stripes

(Triangle | delta): What interference fringes looked blurry

×: interference fringes clearly visible

(Evaluation of adhesion)

About the optical film of the said Example and a comparative example, the adhesion rate of the checkerboard scale adhesion test shown below was measured, respectively.

In addition, about the comparative example 12, surface shape was bad and it could not measure.

(Checker scale adhesion test)

A checkerboard scale of 100 divisions was put in a square of 1 mm on one side of the HC layer side surface of the optical film, and five consecutive peel tests were performed using an industrial 24mm cello tape (registered trademark) manufactured by Nichiban Co., Ltd. The ratio of the scale which remained without peeling computed based on was calculated | required.

Adhesion rate (%) = (number of scales not peeled off / total number of scales 100) × 100

(Evaluation of surface shape)

The surface shape (with or without coating streak) of the external appearance of the optical film was evaluated visually.

○: no coating streaks

△: coating coating streaked faintly

×: coating coating streaked clearly

(Summary of results)

In Example 2 from Table 2, both reflectance and haze were low. In the Example, the total light transmittance was a high value of 91.5% or more. Moreover, in the Example, generation | occurrence | production of the interference fringe was suppressed all. Moreover, adhesiveness and surface shape were also favorable in the Example. In particular, the surface shape of Example 1 and Example 2 was favorable.

7 and 8 which are sectional views of the optical film of Example 1, it turns out that hollow silica microparticles | fine-particles take the distribution which becomes smaller from the opposite side (upper layer side) to the TAC base material side of HC layer, and FIG. 8 It turns out that most of the hollow silica fine particles are distributed from the interface on the side opposite to the TAC substrate of the HC layer to 5 µm.

7 to 9, it can be seen that in Example 1, the boundary between the cured portion of the first composition and the cured portion of the second composition is not as clear as in Comparative Example 3.

However, in the comparative example 1 which corresponds to the case where there is no 2nd composition in Example 1, since the hollow silica microparticles were not contained, it became the same reflectance only as a general hard coat layer.

In the comparative example 2 which corresponded to the case where there is no 1st composition in Example 1, interference fringes generate | occur | produced and the adhesiveness rate was also low. It is assumed that the interference fringes are caused by the fact that the hollow silica fine particles contained in the second composition are uniformly distributed in the HC layer and located at the TAC substrate side interface of the HC layer, whereby the refractive index difference between the TAC substrate and the hollow silica fine particles is increased. Moreover, when hollow silica microparticles | fine-particles are located in the TAC base material side interface of HC layer in this way, it is estimated that the area which resin of a HC layer penetrates and hardens | cures and the adhesiveness fell.

In the comparative example 3 which corresponded to the case where application was carried out instead of simultaneous application in Example 1, the interference fringe was observed faintly. As shown in the cross-sectional photograph of FIG. 9, the boundary between the cured portion of the first composition and the cured portion of the second composition is clearly distinguished, and it is presumed that interference fringes are caused by the refractive index difference of the boundary portion.

In the comparative example 4 which corresponds to the case where there is no 2nd composition in Example 2, similarly to the comparative example 1, reflectance became the reflectance similar to only the general hard-coat layer.

In the comparative example 5 which corresponds to the case where there is no 1st composition in Example 2, interference fringes generate | occur | produced similarly to the comparative example 2, and the adhesiveness rate was also low.

In Comparative Example 6 corresponding to the case where preliminary curing was performed before drying in Example 2, the adhesion rate was low. This is because the curing of the first composition and the second composition (polymerization or crosslinking of the resin) proceeds by preliminary curing, and the first resin contained in the first composition on the TAC base material side does not sufficiently penetrate into the TAC base material. It is assumed.

In Comparative Example 7, which corresponds to the case where there was no first composition in Example 5, an interference fringe was generated similarly to Comparative Example 2, and the adhesion rate was also low.

In the comparative example 8 which corresponds to the case where there is no 2nd composition in Example 10, it became the same reflectance only as the general hard-coat layer like the comparative example 1.

In the comparative example 9 which corresponds to the case where there is no 1st composition in Example 10, interference fringes generate | occur | produced similarly to the comparative example 2, and the adhesiveness rate was also low.

In Comparative Example 10, in which the viscosity of both the first composition and the second composition in Example 1 was small, the reflectance was lower than that of Comparative Example 1 and higher than that of Example 1. This is presumably because the mixing of the two compositions proceeds due to the low viscosity of the two compositions, and the hollow silica fine particles present on the opposite side (upper layer side) of the HC layer is reduced, and the reflectance is increased.

In Example 1, when the viscosity of the 2nd composition on the upper layer side of HC layer was small, the surface shape was not good.

In Comparative Example 12, which corresponds to the case where the viscosity difference between the first composition and the second composition in Example 1 is large, streaks on the surface of the HC layer are generated in a large amount, the surface is not smooth, and light scatters, thereby reflecting, Haze and total light transmittance could not be measured.

In Comparative Example 13 corresponding to the case where a mixture of the first composition and the second composition was uniformly applied in Example 1, the reflectance became equivalent to Comparative Example 10. FIG. In addition, interference fringes occurred and the adhesion rate was low. It is estimated that this is because the hollow silica fine particles existing on the side opposite to the TAC substrate of the HC layer was reduced and the reflectance was increased by uniformly mixing and applying the two compositions. In addition, as in Comparative Example 2, it is estimated that the interference fringes are generated by the presence of hollow silica fine particles located at the TAC substrate side interface of the HC layer, and the adhesion rate is lowered.

1: Optical film
2: polarizer
10: light transmissive substrate
20: hard coat layer
30: low refractive index fine particle
40: die head
51, 52: slit
60: curable resin composition for 1st hard-coat layer
61: Coating film of curable resin composition for 1st hard-coat layer
70: curable resin composition for a second hard coat layer
71: coating film of curable resin composition for 2nd hard-coat layers
80: coater gap
90: total wet film thickness of the first and second compositions
100: conventional antireflection film
110: conventional hard coat layer
120: low refractive index layer
130: conveyance direction of the light transmissive substrate
140: antistatic layer
150: antifouling layer
160: protective film
170: polarizing layer
180: polarizer

Claims (9)

(i) preparing a light-transmitting substrate,
(ii) 5.0 mass% or less with respect to the mass of the said 1st resin, even if it contains the 1st resin and 1st solvent which have reactivity, and it does not contain low refractive index microparticles | fine-particles and low refractive index resin, or contains low refractive index resin, At least one low refractive index component selected from the group consisting of a curable resin composition for a hard coat layer having a viscosity μ1 of 3 mPa · s or more, a low refractive index fine particle having an average particle diameter of 10 to 300 nm, and a low refractive index resin, and a second resin having reactivity And a second solvent, wherein the step of preparing a curable resin composition for a second hard coat layer having a viscosity of 2 m or more and 5 mPa · s or less and the value of 1 µm or less is 30 mPa · s or less;
(iii) at least one curable resin composition for the first hard coat layer and the curable resin composition for the second hard coat layer adjacent to one surface side of the light transmissive substrate from the light transmissive substrate side to be coated simultaneously to form a coating film;
(iv) drying the coating film obtained in the step (iii), followed by curing by light irradiation, heating or both, and further preliminary curing between the step (iii) and the step (iv). The manufacturing method of the optical film characterized by not performing. The wet film thickness of the coating film of the curable resin composition for hard coat layers of T1 and the wet film thickness of the coating film of the curable resin composition for hard coat layers of 2nd said T3 in the said (iii) process of Claim 1, And T2 / T1 is 0.01-1, The manufacturing method of the optical film characterized by the above-mentioned. 3. The wet film thickness of the coating film of the curable resin composition for a second hard coat layer according to claim 2, wherein in the step (iii), the wet film thickness T1 of the coating film of the curable resin composition for a first hard coat layer is 18.75 to 25 µm. The manufacturing method of the optical film whose T2 is 1-10 micrometers, and the film thickness of the hard-coat layer after the said (iv) process is 5-18 micrometers. The viscosity μ1 of the curable resin composition for a first hard coat layer is 3 to 95 mPa · s, and the viscosity μ2 of the curable resin composition for the second hard coat layer is 5 to 100 mPa · s. Method for producing a film. The optical film obtained by the manufacturing method in any one of Claims 1-4. 6. The method of claim 5,
In the film thickness direction of the hard coat layer, more low refractive index fine particles exist on the interface side opposite to the light transmissive substrate than on the light transmissive substrate side, and the amount of the low refractive index fine particles is greater on the light transmissive substrate side. And the low refractive index component gradually decreases from the interface on the opposite side to the light-transmissive substrate to the light-transmissive substrate side,
There is no layer interface in the hard coat layer,
The adhesion rate of the checkerboard scale adhesion test with respect to the said light transmissive base material of the said hard-coat layer is 90 to 100%, The optical film characterized by the above-mentioned. The total amount of the said low refractive index microparticles | fine-particles of Claim 5 in the film thickness direction of the said hard-coat layer in the area | region from the interface on the opposite side to the said light transmissive base material to 70% of the dry film thickness of the said hard-coat layer. 70 to 100% of the optical film is present. The polarizer is provided in the light transmissive base material on the opposite side to the said hard-coat layer side of the optical film of Claim 5, The polarizing plate characterized by the above-mentioned. The display panel is arrange | positioned at the light transmissive base material on the opposite side to the said hard-coat layer side of the optical film of Claim 5, The display characterized by the above-mentioned.

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