JP2013071314A - Acrylic resin film, method of producing the same, and polarizing plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acrylic resin film which prevents cracks even when a heat cycle test is executed in the case where surface treatment such as a glare-proof layer and a hard coat layer is applied and which is attached to a polarizing film to form a polarizing plate hard to be peeled off from a glass substrate in a high temperature environment when the polarizing plate is attached to the glass substrate, a method of producing the acrylic resin film, and the polarizing plate formed by attaching the acrylic resin film to the polarizing film.SOLUTION: The acrylic resin film 12 is formed by melting and kneading acrylic resin, extruding a film-shaped object 10 from a T die 2, molding a film-shaped molded body 11 by sandwiching the film-shaped object 10 between a first cooling roll 3 and a second cooling roll 4, and cutting a side end of the film-shaped molded body 11. Thickness accuracy of the acrylic resin film 12 in the flowing direction is within 3%, and thickness accuracy in the direction orthogonal to the flowing direction is within 2%.

Description

  The present invention relates to an acrylic resin film obtained by melt-extruding an acrylic resin, a method for producing the same, and a polarizing plate using the acrylic resin film.

  A film made of a thermoplastic resin is used as a light diffusion film, a protective film for protecting the surface of a component of the flat panel display, or the like in a flat panel display such as a liquid crystal display device or a plasma display. In addition, an antiglare layer, a hard coat layer, or the like may be provided on the surface of the thermoplastic resin film used in the flat panel display.

  For example, a polarizing plate used for a liquid crystal panel incorporated in a liquid crystal display device is usually configured by laminating a protective film on one surface of a polyvinyl alcohol polarizing film. The polarizing plate is used in a state where a glass substrate is bonded to the surface on the polarizing film side in a liquid crystal panel. Conventionally, a triacetyl cellulose film has been used as a protective film for a polyvinyl alcohol polarizing film constituting such a polarizing plate.

  The triacetyl cellulose film is suitably used as a protective film for a polarizing film because it has excellent transparency and low optical anisotropy.

However, a triacetyl cellulose film is usually formed by a cast casting method, but since an organic solvent is used in such a forming method, the environmental load is large.
Therefore, there is a demand for a thermoplastic resin film that has a low environmental load during molding and has excellent transparency and low optical anisotropy.

  As a method for producing a thermoplastic resin film, there are an inflation method, a calendar method, a T-die method, and the like.

  In the T-die method, a molten thermoplastic resin is extruded into a sheet or film form from a die having a slit-like lip, and the extruded molten thermoplastic resin is sandwiched between two metal rolls and cooled and solidified at the same time. This is a method for producing a resin film (see Patent Document 1, etc.). Such a T-die method can produce a resin film with good thickness accuracy as compared with other resin film production methods, and further eliminates the need for using an organic solvent and has a low environmental impact. Widely adopted as a method for producing resin films.

  An acrylic resin is known as a thermoplastic resin having excellent transparency and low optical anisotropy. Patent Document 2 discloses an acrylic resin manufactured by a T-die method using an acrylic resin. A film is disclosed.

JP 2011-089027 A JP 2009-160891 A

  However, as in Patent Document 2, an antiglare layer is formed on one surface of an acrylic resin film manufactured by the T-die method using an acrylic resin, and left in a high temperature environment and in a low temperature environment. When the heat cycle test was repeated, cracks might occur in the antiglare layer. Furthermore, assuming use in a liquid crystal panel, an acrylic resin film surface having an antiglare layer formed on one surface is bonded to a polarizing film to produce a polarizing plate, When the polarizing film surface in a polarizing plate was bonded to the glass substrate, the polarizing plate might peel from the glass substrate in a high temperature environment.

  Therefore, the problem of the present invention is that when surface treatment such as an antiglare layer or a hard coat layer is applied, cracks are hardly generated even when a heat cycle test is performed, and the polarizing plate is bonded to a polarizing film. Furthermore, when the polarizing plate is bonded to a glass substrate, an acrylic resin film that can be a polarizing plate that is difficult to peel from the glass substrate in a high temperature environment, a method for producing the same, and the acrylic resin film is a polarizing film It is providing the polarizing plate bonded by this.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

That is, this invention consists of the following structures.
(1) Melting and kneading an acrylic resin, extruding a film-like material from a T-die, sandwiching the film-like material between a first cooling roll and a second cooling roll to form a film-shaped molded article, An acrylic resin film obtained by cutting the side end of the film-shaped molded body,
The acrylic resin film, wherein the acrylic resin film has a thickness accuracy of 3% or less in the flow direction and a thickness accuracy of 2% or less in a direction perpendicular to the flow direction.
(2) The film-shaped molded body width (W _f ) in the direction orthogonal to the flow direction of the film-shaped molded body and the die width (W _d ) of the T die are 0.85 ≦ W _f / W _d ≦ The acrylic resin film according to (1), which satisfies a relationship of 0.95.
(3) An acrylic resin film width (W) in a direction perpendicular to the flow direction of the acrylic resin film and a film-like molded body width (W _f ) in a direction perpendicular to the flow direction of the film-like molded body. The acrylic resin film according to (1) or (2), which satisfies a relationship of 0.70 ≦ W / W _f ≦ 0.90.
(4) The acrylic resin film according to any one of (1) to (3), wherein the acrylic resin contains rubber particles.
(5) A polarizing plate obtained by bonding the acrylic resin film according to any one of (1) to (4) to a polarizing film.
(6) Melting and kneading the acrylic resin, extruding the film-like material from the T-die, sandwiching the film-like material between the first cooling roll and the second cooling roll to form a film-like molded product, A method for producing an acrylic resin film by cutting a side end portion of a film-shaped molded body, wherein the die width (W _d ) of the T die and a direction orthogonal to the flow direction of the film-shaped molded body A method for producing an acrylic resin film, wherein the width of the film-like formed body (W _f ) satisfies a relationship of 0.85 ≦ W _f / W _d ≦ 0.95.
(7) The film-shaped molded body width (W _f ) in the direction orthogonal to the flow direction of the film-shaped molded body and the acrylic resin film width (W) in the direction orthogonal to the flow direction of the acrylic resin film. The manufacturing method according to (6), wherein a relationship of 0.70 ≦ W / W _f ≦ 0.90 is satisfied.

  According to the acrylic resin film of the present invention, when surface treatment such as an antiglare layer or a hard coat layer is applied, generation of cracks in a high temperature environment is suppressed, and the polarizing plate is bonded to a polarizing film. Furthermore, when the polarizing plate is bonded to a glass substrate, peeling of the polarizing plate from the glass substrate in a high temperature environment can be suppressed. In addition, a polarizing plate using an acrylic resin film can be suitably used in a liquid crystal display device in which the inside of the device may be in a high temperature environment because peeling from the glass substrate is suppressed.

It is a schematic explanatory drawing which shows one Embodiment of the manufacturing method of the acrylic resin film of this invention.

  The acrylic resin film of the present invention is obtained by melt-extruding an acrylic resin and molding with a cooling roll. The thickness accuracy in the flow direction of the film is 3% or less and the direction orthogonal to the flow direction (hereinafter referred to as width). The thickness accuracy is sometimes within 2%.

(Acrylic resin)
For example, methacrylic resin is used as the acrylic resin. The methacrylic resin is a polymer mainly composed of a methacrylic acid ester, and may be a homopolymer of the methacrylic acid ester. A copolymer may also be used. Here, as the methacrylic acid ester, an alkyl ester of methacrylic acid is usually used.

  The preferred monomer composition of the methacrylic resin is 50 to 100% by weight of alkyl methacrylate, 0 to 50% by weight of alkyl acrylate, and 0 to 49% by weight of other monomers based on all monomers. More preferably, the alkyl methacrylate is 50 to 99.9% by weight, the alkyl acrylate is 0.1 to 50% by weight, and other monomers are 0 to 49% by weight.

  Examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and the like, and the alkyl group usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. Of these, methyl methacrylate is preferred.

  Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. The alkyl group usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms.

The monomer other than alkyl methacrylate and alkyl acrylate may be, for example, a monofunctional monomer, that is, a compound having one polymerizable carbon-carbon double bond in the molecule, or polyfunctional. Although it may be a monomer, that is, a compound having at least two polymerizable carbon-carbon double bonds in the molecule, a monofunctional monomer is particularly preferable.
Examples of the monofunctional monomer include styrene monomers such as styrene, α-methylstyrene, and vinyl toluene; alkenyl cyanide such as acrylonitrile and methacrylonitrile; acrylic acid; methacrylic acid; maleic anhydride; N -Substituted maleimide and the like.
Examples of the polyfunctional monomer include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate; allyl acrylate, allyl methacrylate, cinnamon Alkenyl esters of unsaturated carboxylic acids such as allyl acids; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate; aromatic polyalkenyl compounds such as divinylbenzene Can be mentioned.

  In addition, as for said alkyl methacrylate, alkyl acrylate, and monomers other than these, respectively, you may use those 2 or more types as needed.

  From the viewpoint of heat resistance, the methacrylic resin preferably has a glass transition temperature of 70 ° C. or higher, more preferably 80 ° C. or higher, and further preferably 90 ° C. or higher. This glass transition temperature can be appropriately set by adjusting the type of monomer and the ratio thereof.

  The methacrylic resin can be prepared by polymerizing the monomer component by a method such as suspension polymerization, emulsion polymerization, or bulk polymerization. At that time, it is preferable to use an appropriate chain transfer agent at the time of polymerization in order to obtain a suitable glass transition temperature or to obtain a melt viscosity showing the moldability of a suitable acrylic resin film. What is necessary is just to determine the addition amount of a chain transfer agent suitably according to the kind of monomer component, its ratio, etc.

(Rubber particles)
The acrylic resin may contain rubber particles. Here, examples of the rubber particles include acrylic rubber particles, butadiene rubber particles, styrene-butadiene rubber particles, and among them, acrylic rubber particles are preferable from the viewpoint of weather resistance and durability.

The acrylic rubber particle is a particle containing an elastic polymer mainly composed of an acrylate ester as a rubber component, and may be a particle having a single layer structure made of only this elastic polymer. Particles having a multilayer structure having a layer and a polymer layer mainly composed of a methacrylic acid ester may be used, but among these, particles having a multilayer structure are preferable from the viewpoint of the surface hardness of the acrylic resin film.
The elastic polymer may be a homopolymer of an acrylate ester or a copolymer of 50% by weight or more of an acrylate ester and 50% by weight or less of other monomers. . Here, as the acrylic ester, an alkyl ester of acrylic acid is usually used.

  A preferable monomer composition of the elastic polymer mainly composed of an acrylate ester is 50 to 99.9% by weight of alkyl acrylate, 0 to 49.9% by weight of alkyl methacrylate, based on all monomers, The monofunctional monomer other than these is 0 to 49.9% by weight, and the polyfunctional monomer is 0.1 to 10% by weight.

Examples of the alkyl acrylate used for forming the elastic polymer are the same as those of the alkyl acrylate described above as the monomer component of the methacrylic resin, and the alkyl group usually has 1 carbon atom. -8, preferably 4-8.
The alkyl methacrylate used when forming the elastic polymer is, for example, the same as the examples of alkyl methacrylate previously mentioned as the monomer component of the methacrylic resin, and the carbon number of the alkyl group is Usually, 1 to 8, preferably 1 to 4.

  Examples of monofunctional monomers other than alkyl acrylate and alkyl methacrylate used in forming the elastic polymer include, for example, other than alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of methacrylic resin. It is the same as that of the example of the monofunctional monomer which is an example of this monomer. Of these, styrene monomers such as styrene, α-methylstyrene and vinyltoluene are preferable.

  The polyfunctional monomer used when forming the elastic polymer is, for example, a polyfunctional monomer that is an example of a monomer other than the alkyl methacrylate and alkyl acrylate listed above as the monomer component of the methacrylic resin. It is the same as that of the example of a functional monomer, Especially, the alkenyl ester of unsaturated carboxylic acid and the polyalkenyl ester of polybasic acid are preferable.

  Alkyl acrylate, alkyl methacrylate, monofunctional monomer other than these, and polyfunctional monomer used when forming the elastic polymer, respectively, use two or more of them as necessary. Also good.

When the acrylic rubber particles having a multilayer structure are used, a preferred example thereof is a polymer layer mainly composed of methacrylic acid ester outside the above-mentioned elastic polymer layer mainly composed of acrylate ester. That is, the above-mentioned elastic polymer mainly composed of an acrylic ester is used as an inner layer, and the polymer mainly composed of a methacrylic ester is used as an outer layer. Here, as the methacrylic acid ester which is a monomer component of the polymer in the outer layer, alkyl methacrylate is usually used.
The outer layer polymer is usually formed at a ratio of 10 to 400 parts by weight, preferably 20 to 200 parts by weight with respect to 100 parts by weight of the inner layer elastic polymer. By setting the polymer of the outer layer to 10 parts by weight or more with respect to 100 parts by weight of the elastic polymer of the inner layer, aggregation of the elastic polymer is difficult to occur, and the transparency of the resulting acrylic resin film is improved.

  The preferred monomer composition of the polymer of the outer layer is based on all monomers, the alkyl methacrylate is 50 to 100% by weight, the alkyl acrylate is 0 to 50% by weight, and other monomers are 0 to 0% by weight. 50% by weight, and 0 to 10% by weight of the polyfunctional monomer.

  Examples of the alkyl methacrylate used when forming the polymer of the outer layer are the same as those of the alkyl methacrylate described above as the monomer component of the methacrylic resin, and the carbon number of the alkyl group is usually 1-8, preferably 1-4. Of these, methyl methacrylate is preferred.

  Examples of the alkyl acrylate used when forming the polymer of the outer layer are the same as those of the alkyl acrylate mentioned above as the monomer component of the methacrylic resin, and the carbon number of the alkyl group is usually 1-8, preferably 1-4.

  As monomers other than alkyl methacrylate and alkyl acrylate used when forming the polymer of the outer layer, for example, other than alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of methacrylic resin It is the same as that of the example of the monofunctional monomer which is an example of a monomer.

  The polyfunctional monomer used when forming the polymer of the outer layer is, for example, an example of monomers other than the alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of the methacrylic resin. This is the same as the example of the polyfunctional monomer.

  In addition, the alkyl methacrylate, the alkyl acrylate, the monomer other than these, and the polyfunctional monomer used when forming the polymer of the outer layer, respectively, use two or more of them as necessary. May be.

  Further, as another preferred example of the acrylic rubber particles having a multilayer structure, inside the elastic polymer layer mainly composed of the above-mentioned acrylic ester which is the inner layer of the above-mentioned two-layer structure, a methacrylate ester is mainly contained. A polymer layer mainly composed of the methacrylic acid ester as an inner layer, an elastic polymer mainly composed of the above acrylate ester as an intermediate layer, and the methacrylic acid ester as a main component. Examples thereof include those having at least a three-layer structure in which the polymer to be used is an outer layer. Here, as a methacrylic acid ester which is a monomer component of the polymer of the inner layer, alkyl methacrylate is usually used. The polymer of the inner layer is usually formed at a ratio of 10 to 400 parts by weight, preferably 20 to 200 parts by weight, with respect to 100 parts by weight of the elastic polymer of the intermediate layer.

  A preferable monomer composition of the polymer of the inner layer is 70 to 100% by weight of alkyl methacrylate, 0 to 30% by weight of alkyl acrylate, and 0 to 30% of other monomers based on all monomers. 30% by weight, and 0 to 10% by weight of the polyfunctional monomer.

  Examples of the alkyl methacrylate used when forming the polymer of the inner layer are the same as the examples of the alkyl methacrylate previously mentioned as the monomer component of the methacrylic resin, and the carbon number of the alkyl group is usually 1-8, preferably 1-4. Of these, methyl methacrylate is preferred.

  The alkyl acrylate used when forming the polymer of the inner layer is, for example, the same as the examples of alkyl acrylate previously mentioned as the monomer component of the methacrylic resin, and the carbon number of the alkyl group is usually 1-8, preferably 1-4.

  As monomers other than alkyl methacrylate and alkyl acrylate used when forming the polymer of the inner layer, for example, other than alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of methacrylic resin It is the same as that of the example of the monofunctional monomer which is an example of a monomer.

  As an example of the polyfunctional monomer used when forming the polymer of the inner layer, it is an example of a monomer other than the alkyl methacrylate and the alkyl acrylate mentioned above as the monomer component of the methacrylic resin. This is the same as the example of the polyfunctional monomer.

  In addition, the alkyl methacrylate used when forming the polymer of the said inner layer, an alkyl acrylate, a monomer other than these, and a polyfunctional monomer respectively use those 2 or more types as needed. Also good.

The acrylic rubber particles can be prepared by polymerizing the monomer component of the elastic polymer mainly composed of the above-described acrylic ester by at least one reaction by an emulsion polymerization method or the like.
At this time, as described above, when a polymer layer mainly composed of methacrylic acid ester is formed outside the elastic polymer layer, the monomer component of the outer layer polymer is added to the elastic polymer layer. What is necessary is just to graft to the said elastic polymer by making it superpose | polymerize by reaction of at least 1 step | paragraph by emulsion polymerization method etc. in presence of a polymer.
Further, as described above, when a polymer layer mainly composed of methacrylic acid ester is formed inside the elastic polymer layer, first, the monomer component of the polymer in the inner layer is Polymerization is performed by at least one stage reaction by an emulsion polymerization method or the like, and then the monomer component of the elastic polymer is polymerized by at least one stage reaction by an emulsion polymerization method or the like in the presence of the resulting polymer. In the presence of the resulting elastic polymer, the monomer component of the outer layer polymer is polymerized in an at least one-stage reaction by an emulsion polymerization method or the like. To be grafted to the elastic polymer. When the polymerization of each layer is performed in two or more stages, it is sufficient that the monomer composition as a whole is within a predetermined range, not the monomer composition of each stage.

  As for the particle size of the acrylic rubber particles, the average particle size of the elastic polymer layer mainly composed of acrylic acid ester in the rubber particles is preferably 0.01 to 0.4 μm, 0.05 to More preferably, it is 0.3 micrometer, and it is still more preferable that it is 0.07-0.25 micrometer. If the average particle diameter of the elastic polymer layer is larger than 0.4 μm, the transparency of the resulting acrylic resin film is lowered, leading to a decrease in transmittance, which is not preferable. Further, if the average particle size of the elastic polymer layer is smaller than 0.01 μm, the surface hardness of the resulting acrylic resin film is lowered and is easily damaged.

In addition, the average particle diameter is a portion obtained by mixing acrylic rubber particles with a methacrylic resin to form a film, dyeing the elastic polymer layer with ruthenium oxide in the cross section, and observing with an electron microscope. It can be calculated from the diameter.
That is, when acrylic rubber particles are mixed with methacrylic resin and the cross section thereof is dyed with ruthenium oxide, the methacrylic resin of the parent phase is not dyed, and the polymer mainly composed of methacrylic acid ester on the outer side of the elastic polymer layer. In this case, the outer layer polymer is not dyed, and only the elastic polymer layer is dyed, so that the dye is dyed in this way, and from the diameter of the portion observed in an approximately circular shape by an electron microscope, The particle diameter can be determined. When a polymer layer mainly composed of methacrylic acid ester is present inside the elastic polymer layer, the polymer of the inner layer is not dyed and the outer elastic polymer layer is dyed 2 In this case, the outer diameter of the two-layer structure, that is, the outer diameter of the elastic polymer layer may be considered.

  The content of the rubber particles contained in the acrylic resin is preferably 10 to 50 parts by weight and more preferably 12 to 40 parts by weight with respect to a total of 100 parts by weight of the acrylic resin and the rubber particles. It is preferably 15 to 30 parts by weight. If the rubber particle content is less than 10 parts by weight, the impact resistance may not be sufficiently improved. If the rubber particle content exceeds 50 parts by weight, the surface hardness of the acrylic resin film May decrease.

(Any component of acrylic resin)
The acrylic resin can contain various additives as required.
Examples of additives include ultraviolet absorbers, organic dyes, inorganic dyes, pigments, antioxidants, antistatic agents, surfactants, lubricants, flame retardants such as silicone compounds, fillers, glass fibers, and impact resistance. Property modifiers and the like. In addition, these additives preferably have a melting point of 180 ° C. or higher in order to evaporate as a volatile component when the acrylic resin is discharged from the die and prevent contamination of the roll or the like.

Examples of the UV absorber include commonly used benzotriazole UV absorbers, 2-hydroxybenzophenone UV absorbers, and salicylic acid phenyl ester UV absorbers.
Examples of the benzotriazole ultraviolet absorber include 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2 -(5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di -Tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-butyl -2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) ben And zotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, and the like.
Examples of the 2-hydroxybenzophenone-based ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-. Examples include chlorobenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.
Examples of the salicylic acid phenyl ester ultraviolet absorber include p-tert-butylphenyl salicylic acid ester and p-octylphenyl salicylic acid ester.

  These ultraviolet absorbers can be used alone or in admixture of two or more. The content of the ultraviolet absorber is appropriately set depending on the thickness of the desired acrylic resin film, preferably 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, and 5 weights. Part or less.

[Method for producing acrylic resin film]
In the method for producing an acrylic resin film of the present invention, the above-described acrylic resin is melt-kneaded, a film-like material is extruded from a T die, and the film-like material is sandwiched between a first cooling roll and a second cooling roll. Is a method for producing an acrylic resin film having excellent thickness accuracy by forming a predetermined film-like molded body and cutting the side end portion of the film-like molded body.
The acrylic resin film may have a single layer configuration made of only an acrylic resin, or may have a multilayer configuration made of a resin layer having a composition different from that of the acrylic resin layer. As a resin layer having a different composition, the resin type constituting the layer may be different from that of the acrylic resin, and even if the resin type is the same acrylic resin, the type and addition of additives to be added The amount should be different.

Hereinafter, an embodiment of a method for producing an acrylic resin film of the present invention will be described in detail with reference to FIG.
As shown in FIG. 1, the acrylic resin charged into the extruder 1 is melt-kneaded, supplied to the T die 2, and then extruded as a film-like object 10 from the tip of the T die 2.

  What is necessary is just to use what has 1 or 2 screws as the extruder 1, and should just select suitably according to the form of resin thrown into an extruder. Moreover, what is necessary is just to add an extruder according to the number of the resin, when an acrylic resin film is a multilayer structure manufactured by melt-coextrusion of 2 or more types of resin.

The T die 2 may be a single layer die that extrudes one type of resin as a single layer, or two types that are independently pumped from the extruder 1 such as a feed block die and a multi-manifold die. It may be a multilayer die in which the above resins are laminated and coextruded.
When the resulting acrylic resin film has a single-layer configuration, a single-layer die may be used, and when it has a multilayer configuration, a multilayer die such as a feed block die or a multi-manifold die may be used.

The die width (W _d ) of the T die 2 may be appropriately adjusted in consideration of the desired length in the width direction of the acrylic resin film 12. At that time, the length (W _f ) in the width direction of the film-shaped molded body 11 and the die width (W _d ) of the T die 2 satisfy the relationship of 0.85 ≦ W _f / W _d ≦ 0.95. It is preferable to satisfy the relationship of 0.90 ≦ W _f / W _d ≦ 0.95. By setting W _f / W _d within the above range, an acrylic resin film having a desired thickness accuracy can be obtained.
In addition, the length ( _Wf ) of the width direction of the film-form molded object 11 can be measured like the evaluation method as described in an Example.

  The lip opening of the T die 2 can be adjusted by opening / closing choke bar bolts arranged in the width direction of the T die so that the thickness of the acrylic resin film 12 is within the range described later. The thickness of the film-like molded body 11 is preferably adjusted to 1.01 to 10 times, more preferably 1.1 to 5 times. The lip opening may be uniform from one end to the other, but may be distributed over the width direction. For example, if the lip opening at both ends is narrower than the lip opening at the center, the draw resonance phenomenon can be more effectively suppressed.

  The T-die 2 includes a screen mesh for filtering and removing relatively large foreign substances contained in the resin supplied from the extruder 1, and a polymer for filtering and removing relatively small foreign substances and gels. A filter may be provided, or a gear pump for stably quantifying the amount of resin to be extruded may be provided.

  The film-like object 10 pushed out from the T die 2 is sandwiched between the first cooling roll 3 and the second cooling roll 4 that are arranged to face each other in a substantially horizontal direction.

  The first cooling roll 3 and the second cooling roll 4 are preferably a metal roll, a metal elastic roll, or a rubber roll. The 1st cooling roll 3 and the 2nd cooling roll 4 may be comprised from the same roll, and may be comprised from a different roll.

  Examples of the metal roll include a drilled roll from which a metal lump has been cut out; a metal roll that can control the temperature of the roll surface through a fluid, steam, or the like inside a roll such as a spiral roll having a hollow structure. The outer peripheral surfaces of these metal rolls may be polished and plated, or may have a desired uneven shape formed by sandblasting or engraving.

  The metal elastic roll is one in which the inside of the roll is made of rubber, or a fluid is injected into the inside of the roll, and the outer peripheral part is made of a metal thin film having flexibility. It is what. Specifically, examples of the metal elastic roll in which the inside of the roll is made of rubber include a silicone rubber roll coated with a cylindrical stainless steel thin film having a thickness of about 0.2 to 1 mm. As a metal elastic roll into which a fluid such as water or oil is injected, a cylindrical thin film made of stainless steel with a thickness of about 2 to 5 mm is fixed at the end of the roll, and the fluid is sealed inside Is mentioned.

  Examples of the rubber roll include a silicone rubber roll and a fluorine rubber roll, and sand rubber may be mixed to improve releasability. The hardness of the rubber roll is preferably in the range of A70 ° to A90 ° measured according to JIS K6253. The hardness of the rubber roll can be arbitrarily set, for example, by adjusting the degree of crosslinking and composition of the rubber constituting the rubber roll.

Thereafter, the film-like object 10 sandwiched between the first cooling roll 3 and the second cooling roll 4 is wound around the second cooling roll 4 as shown in FIG. The film is passed between the three cooling rolls 5, further wound around the third cooling roll 5, and formed into a film-like molded body 11.
Thus, by providing the 3rd cooling roll 5 after the 2nd cooling roll 4, since the film-like thing 10 is cooled slowly, the optical distortion of the film-form molded object 11 obtained can be made small.

A predetermined gap is provided between the second cooling roll 4 and the third cooling roll 5, and when the film-like object 10 is passed between the second cooling roll 4 and the third cooling roll 5, the film It may be in a so-called released state in which the sheet-like object 10 does not receive pressure from the second cooling roll 4 and the third cooling roll 5, or the film-like object 10 receives pressure from the second cooling roll 4 and the third cooling roll 5. May be sandwiched between both rolls.
In addition, in order to cool the film-like object 10 more gently, the 4th, 5th,... And a plurality of cooling rolls are provided after the third cooling roll 5, and the film wound around the third cooling roll 5. You may install so that the shape 10 may be wound around the next cooling roll sequentially.
Moreover, in this invention, the structure of a cooling roll may be only the 1st cooling roll 3 and the 2nd cooling roll 4 which excluded the 3rd cooling roll 5 or later.

  The obtained film-like molded body 11 is cut by the cutting unit 6 to obtain an acrylic resin film 12. In addition, although the cutting | disconnection of an edge part is normally made | formed about the both ends of the film-form molded object 11, only one edge part may be cut | disconnected.

The cutting unit 6 usually includes an upper round blade 6a and a lower round blade 6b.
The upper round blade 6a and the lower round blade 6b have substantially the same diameter, and are arranged in a pair of upper and lower sides so that the blade edges are in sliding contact with each other. Each of the upper round blade 6a and the lower round blade 6b is connected to rotation driving means such as an electric motor so that the upper round blade 6a and the lower round blade 6b can independently rotate at a predetermined peripheral speed. It is configured. Therefore, if each of the upper round blade 6a and the lower round blade 6b is rotated, and the film-shaped molded body 11 is passed between the upper round blade 6a and the lower round blade 6b in the rotated state, the film-shaped molded body 11 is used. The acrylic resin film 12 with the side edges cut can be obtained.

The side edge to be cut, that is, the distance (L) from the side edge of the film-shaped molded body 11 toward the inside of the film, the length (W _f ) in the width direction of the film-shaped molded body 11, and the desired acrylic resin What is necessary is just to set suitably from the length (W) of the width direction of the film 12. FIG.
At this time, W _f and W preferably satisfy the relationship of 0.70 ≦ W / W _f ≦ 0.90, and more preferably satisfy the relationship of 0.80 ≦ W / W _f ≦ 0.90. preferable. W / W _f being 0.70 or more means that the acrylic resin film 12 is obtained with a yield of 70% or more with respect to the film-shaped molded body 11, and has high thickness accuracy. In addition, it has high productivity. When W / W _f is less than 0.70, the yield of acrylic resin film 12 is lower relative to the film-like molded body 11, the W / W _f is more than 0.90, the acrylic to the film-like molded body 11 Although the yield of the resin resin film 12 is high, the thickness accuracy of the acrylic resin film 12 may be reduced.

<Acrylic resin film>
Thus, the acrylic resin film 12 having excellent thickness accuracy is obtained.
The acrylic resin film 12 has a thickness accuracy of 3% or less in the flow direction of the acrylic resin film 12 and a thickness accuracy of 2% or less in the width direction. In particular, the thickness accuracy in the flow direction is 2% or less. And the thickness accuracy in the width direction is preferably within 2%.
If the thickness accuracy is within the predetermined range, an acrylic resin film is bonded to a polarizing film to form a polarizing plate, and when the polarizing plate and a glass substrate are further bonded, in a high temperature environment of 50 ° C. or higher. In, peeling of the polarizing plate from the glass substrate can be suppressed. That is, the acrylic resin film of the present invention is suitably used as a protective film for a polarizing plate in a liquid crystal panel.
In addition, when the thickness accuracy is within the predetermined range, when an acrylic resin film is used as an optical film, on the surface of the acrylic resin film, for example, an antiglare layer, an antireflection layer, an antiblocking layer, a hard coat layer Surface treatment such as coating is provided by coating, etc., but at this time, the thickness of the coating layer can be uniformly applied, and the optical characteristics of the acrylic resin film as an optical film can be made uniform. However, even when the heat cycle test is performed in which the optical film is left in a high temperature environment of, for example, 70 ° C. for 1 hour and then left in a low temperature environment of −35 ° C. for 1 hour, cracks are hardly generated.

In order to make the thickness accuracy in the flow direction of the acrylic resin film 12 within the predetermined range, for example, the amount of discharge from the T-die is adjusted so that the discharge amount per time becomes a constant amount, or a melt-extruded film shape What is necessary is just to adjust so that the space | interval (roll gap) between the two cooling rolls which pinch | interpose the thing 10 may become a fixed space | interval.
Further, in order to make the thickness accuracy in the width direction of the acrylic resin film within the predetermined range, for example, the opening degree of the lip of the T die or the temperature of the die may be adjusted.
In particular, a factor that greatly affects the thickness accuracy in the flow direction and the thickness accuracy in the width direction is the fluctuation of the discharge amount at the end of the T die, that is, the occurrence of a so-called draw resonance phenomenon. The die width (W _d ) of the die and the length (W _f ) in the width direction of the film-shaped molded body 11 are adjusted so as to satisfy the relationship of 0.85 ≦ W _f / W _d ≦ 0.95. It is good to do. At this time, it is preferable that the length (W) in the width direction of the acrylic resin film and the length (W _f ) in the width direction of the film-shaped molded body satisfy the predetermined relationship.

Here, the thickness accuracy in the flow direction of the acrylic resin film is indicated by the thickness accuracy at the side end portion of the film. For example, the film is divided into 10 equal parts in the width direction, and any one of the first to third rows is arranged. The thickness of 24 points was measured with a micrometer at intervals of 50 mm in the flow direction, and the maximum value, the minimum value, and the average value of the measured 24 points were calculated by the following formulas (A) and (B). Of the calculated values, the larger value is indicated. The side edge of the film was evaluated because the thickness of the side edge in the width direction of the acrylic resin film tends to be thicker than the thickness of the center, and the side edge from the center in the width direction of the acrylic resin film. This is because the thickness accuracy in the flow direction of the acrylic resin film tends to decrease.
[(Maximum value−average value) / average value] × 100 (A)
[(Average value−minimum value) / average value] × 100 (B)
The thickness accuracy in the width direction of the acrylic resin film is to cut out a strip-shaped sample having a length in the flow direction of 50 mm, and the sample has 20 points or more, preferably 30 points or more at equal intervals in the width direction. The thickness is measured with a micrometer, and the larger one of the values calculated by the above formulas (A) and (B) from the maximum value, the minimum value, and the average value of the measurement points. In addition, what is necessary is just to set a measurement space | interval so that it may become about 1-2% with respect to the length in the width direction of an acrylic resin film, for example, the length in the width direction of an acrylic resin film shall be 1330 mm, and is measured. When the number of points is 54, the measurement interval may be 25 mm.

  The acrylic resin film preferably has a thickness of 30 to 200 μm, more preferably 50 to 150 μm, and still more preferably 60 to 100 μm.

  The length in the width direction of the acrylic resin film is preferably 100 to 1800 mm, more preferably 300 to 1600 mm, and further preferably 500 to 1400 mm. If the length in the width direction exceeds 1800 mm, the material strength and processing accuracy of the roll will be low, and the roll gap cannot be maintained uniformly, resulting in a decrease in thickness accuracy in the flow direction and a slit in the T die. The material strength and processing accuracy of the lip-shaped lip are likely to be low, and it is difficult to adjust the lip opening, so that the thickness accuracy in the width direction of the acrylic resin film 12 is likely to be low. On the other hand, if the length in the width direction is less than 100 mm, the production efficiency is low.

[Functions that can be arbitrarily added to the acrylic resin film]
The acrylic resin film may be subjected to surface treatment such as hard coat treatment, antistatic treatment, antireflection treatment, antifouling treatment, and antiglare treatment.

(Hard coat layer of acrylic resin film)
The hard coat layer has a function of increasing the surface hardness of the acrylic resin film, and is provided, for example, for the purpose of preventing scratches on the surface in the assembly process of the liquid crystal module. The hard coat layer is a pencil hardness test defined in JIS K 5600-5-4: 1999 “Paint General Test Method—Part 5: Mechanical Properties of Coating Film—Section 4: Scratch Hardness (Pencil Method)” It is preferable that the optical film on which the hard coat layer is formed is placed on a glass plate and measured) to show a value of 2H or harder.

  Examples of the material for forming the hard coat layer include photocurable resins, thermosetting resins, electron beam curable resins, inorganic materials such as silicon dioxide, among others, productivity and hardness of the coating film to be obtained. From such viewpoints, a photocurable resin is preferred.

(Photo-curing resin used for hard coat treatment of acrylic resin film)
As photocurable resin, for example, polyfunctional acrylate; polyfunctional urethanized acrylate, polyol (meth) acrylate, and photocurable containing (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups as required. A mixture etc. are mentioned. Especially, since the adhesive force with respect to the acrylic resin film of a base material is favorable and it is excellent in productivity, a photocurable mixture is preferable.

  Examples of the polyfunctional acrylate include dimethyl or tri-acrylate of trimethylolpropane, tri- or tetra-acrylate of pentaerythritol, polyfunctional which is a reaction product of acrylate having at least one hydroxyl group in the molecule and diisocyanate. Examples thereof include urethanized acrylate. These polyfunctional acrylates can be used alone or in combination of two or more as required.

As a polyfunctional urethanized acrylate used when forming the said photocurable mixture, it manufactures using (meth) acrylic acid and / or (meth) acrylic acid ester, a polyol, and diisocyanate, for example. Specifically, by preparing hydroxy (meth) acrylate having at least one hydroxyl group in the molecule from (meth) acrylic acid and / or (meth) acrylic acid ester and polyol, and reacting it with diisocyanate, Multifunctional urethanized acrylates can be produced.
The polyfunctional urethanized acrylate thus produced has a function as the above-described photocurable resin. In the production thereof, (meth) acrylic acid and / or (meth) acrylic acid ester may be used singly or in combination of two or more, respectively, and polyol and diisocyanate are similarly used. One type may be used, or two or more types may be used in combination.

  As the (meth) acrylic acid ester used for forming the polyfunctional urethanized acrylate, a linear or cyclic alkyl ester of (meth) acrylic acid can be used, and specific examples thereof include methyl (meth) acrylate. And alkyl (meth) acrylates such as ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) acrylate; cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate, and the like.

  The polyol used for forming the polyfunctional urethanized acrylate is a compound having at least two hydroxyl groups in the molecule, and specific examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, diethylene glycol, and diethylene glycol. Propylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl- 1,3-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol ester of hydroxypivalic acid, cyclohexane dimethylol, 1,4-cyclohexane diol, spiro glycol, tricyclodecane dimethylol, hydrogenated bisphenol , Ethylene oxide-added bisphenol A, propylene oxide-added bisphenol A, trimethylolethane, trimethylolpropane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, etc. Is mentioned.

  The diisocyanate used in forming the polyfunctional urethanized acrylate is a compound having two isocyanato groups (—NCO) in the molecule, and various aromatic, aliphatic or alicyclic diisocyanates can be used. Specific examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4, Examples thereof include 4'-diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and a nuclear hydrogenated diisocyanate having an aromatic ring among these.

  The polyol (meth) acrylate used for forming the photocurable mixture is a (meth) acrylate of a compound having at least two hydroxyl groups in the molecule (that is, polyol). Examples include erythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and the like. These polyol (meth) acrylates may be used alone or in combination, and preferably contain pentaerythritol triacrylate and / or pentaerythritol tetraacrylate.

  The (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups used in forming the photocurable mixture has an alkyl group containing two or more hydroxyl groups in one structural unit, Specific examples include a polymer containing 2,3-dihydroxypropyl (meth) acrylate as a constituent unit, a polymer containing 2-hydroxyethyl (meth) acrylate as a constituent unit together with 2,3-dihydroxypropyl (meth) acrylate, and the like. Is mentioned.

  As described above, by using the acrylic photo-curing resin as exemplified, the hard coat can improve the adhesion with the acrylic resin film, improve the mechanical strength, and effectively prevent the surface from being scratched. A layer can be obtained.

(Photopolymerization initiator compounded in the photocurable resin composition used for hard coat treatment of acrylic resin film)
Such a photocurable resin is combined with a photopolymerization initiator to form a photocurable resin composition.
Examples of the photopolymerization initiator include acetophenone series, benzophenone series, benzoin ether series, amine series, and phosphine oxide series.

Examples of the acetophenone photopolymerization initiator include 2,2-dimethoxy-2-phenylacetophenone (also known as benzyldimethyl ketal), 2,2-diethoxyacetophenone, and 1- (4-isopropylphenyl) -2-hydroxy-2. -Methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one and the like.
Examples of the benzophenone photopolymerization initiator include benzophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, and the like.
Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether and benzoin propyl ether.
Examples of the amine photopolymerization initiator include N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone (also known as Michler's ketone).
Examples of the phosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
In addition, xanthone compounds and thioxant compounds can also be used as photopolymerization initiators.

  Examples of commercially available photopolymerization initiators include “Irgacure 907” and “Irgacure 184” sold by Ciba, Switzerland, “Lucirin TP0” sold by BASF, Germany, and the like. .

(Other components blended in the photocurable resin composition used for hard coat treatment of acrylic resin film)
If necessary, the photo-curable resin composition may be added with a solvent to form a coating solution, or may contain a leveling agent or the like.
Examples of the solvent include any organic solvent that can dissolve each component constituting the photocurable resin composition, such as ethyl acetate and butyl acetate, and a mixture of two or more organic solvents may be used. it can.

Examples of the leveling agent include a fluorine-based or silicone-based leveling agent.
Examples of the silicone-based leveling agent include reactive silicone; polydimethylsiloxane, polyether-modified polydimethylsiloxane, polymethylalkylsiloxane, and the like, among which reactive silicone and siloxane-based leveling agent are preferable.
When a leveling agent made of reactive silicone is used, the surface of the hard coat layer is provided with slipperiness, and excellent scratch resistance can be maintained for a long period of time. Further, if a siloxane leveling agent is used, film formability can be improved.

The method for forming the hard coat layer may be appropriately selected depending on the material for forming the hard coat layer. For example, when a material that is cured by light is included, a coating solution containing the material is immersed in the surface of the acrylic resin film. After being attached by a method such as spraying, coating, etc., a method in which the material is crosslinked and cured by irradiating it with an active energy ray such as ultraviolet ray or electron beam; Examples of the method include a method in which the coating liquid is attached to the surface of the acrylic resin film by a method such as dipping, spraying, or coating, and then heated to crosslink and cure to coat.
The thickness of the hard coat layer is usually about 0.1 to 30 μm.

  The hard coat layer contains various fillers for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage, and improving heat resistance, antistatic properties, antiglare properties, etc., if desired. can do. The hard coat layer can also contain additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a leveling agent, and an antifoaming agent.

(Antistatic layer of acrylic resin film)
The antistatic layer is provided for the purpose of imparting conductivity to the surface of the acrylic resin film and suppressing the influence of static electricity.
In particular, when using the acrylic resin film of the present invention as a protective film for a polarizing film and forming a polarizing plate, the antistatic function can be imparted by subjecting the above acrylic resin film to surface treatment, It can also be applied to other portions of the polarizing plate in which this acrylic resin film is incorporated, such as an adhesive layer.
Examples of the material for forming the antistatic layer include cationic antistatic agents such as quaternary ammonium salt type and phosphonium salt type, anionic antistatic agents such as carboxylic acid type and sulfonate type, sulfobetaine type, and alkyl group. Ionic antistatic agent such as amphoteric ionic antistatic agent such as betaine type; conductive polymer such as polyaniline, polythiophene, polypyrrole, polyquinoxaline; various surfactants (cationic, anionic and amphoteric surfactants) , Metals and metal oxides.
Examples of the method for forming the antistatic layer include a method of applying a resin composition containing the material for forming the antistatic layer described above. Specifically, the material for forming the hardcoat layer described above is used. A method of coating the coating solution containing the above-described material for forming the antistatic agent may be used. Thereby, an antistatic hard coat layer can be formed.

(Anti-reflective layer of acrylic resin film)
The antireflection layer is provided for the purpose of preventing reflection of outside light from being prevented.
It is provided directly on the surface (surface exposed to the outside) of the acrylic resin film or via another layer such as a hard coat layer or an antiglare layer. The acrylic resin film provided with the antireflection layer preferably has a reflectance of 2% or less at an incident angle of 5 ° with respect to light having a wavelength of 430 to 700 nm, and in particular, at the same incident angle with respect to light having a wavelength of 550 nm. The reflectance is preferably 1% or less.

The thickness of the antireflection layer can be about 0.01 to 1 μm, and more preferably in the range of 0.02 to 0.5 μm.
The antireflective layer has a refractive index smaller than the refractive index of the surface material (acrylic resin film, hard coat layer, etc.) on which the antireflective layer is provided, specifically a refractive index of 1.30 to 1.45. And a thin film made of an inorganic compound, and a thin film made of an inorganic compound and a plurality of high refractive index layers laminated alternately.

  The material used for forming the low refractive index layer is not particularly limited as long as it has a low refractive index. For example, a resin material such as an ultraviolet curable acrylic resin; an inorganic material such as colloidal silica in the resin; Examples include a hybrid material in which fine particles are dispersed; a sol-gel material containing alkoxysilane; a sol material in which inorganic compound fine particles are dispersed in an alcohol solvent.

  As a method for forming such a low refractive index layer, for example, a method of applying a polymerized polymer of the above material; applying in the state of a monomer or oligomer that becomes a precursor of the polymer as the above material, and then polymerizing and curing The method etc. are mentioned. Moreover, it is preferable that each material contains the compound which has a fluorine atom in a molecule | numerator, in order to provide antifouling property.

Examples of the sol-gel material used for forming the low refractive index layer include those having fluorine atoms in the molecule such as polyfluoroalkylalkoxysilane.
Polyfluoroalkylalkoxysilanes can be represented, for example, by the formula:
CF ₃ (CF ₂ ) _n CH ₂ CH ₂ Si (OR) ₃
Wherein R represents an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 12, and among them, n in the above formula is 2 to 6 Compounds are preferred.

  Specific examples of the polyfluoroalkylalkoxysilane include 3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,4,4,5,5,6,6. , 7,7,8,8,8-tridecafluorooctyltrimethoxysilane, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltri Ethoxysilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltrimethoxysilane, 3,3,4 4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltriethoxysilane.

The low refractive index layer can also be composed of a cured product of a thermosetting fluorine-containing compound or an ionizing radiation-curable fluorine-containing compound.
The cured product preferably has a dynamic friction coefficient in the range of 0.03 to 0.15, and preferably has a contact angle with water in the range of 90 to 120-.
Examples of the curable fluorine-containing compound include a polyfluoroalkyl group-containing silane compound (for example, the above-mentioned 3,3,4,4,5,5,6,6,7,7,8,8,9,9, 10,10,10-heptadecafluorodecyltriethoxysilane, etc.) and fluorine-containing polymers having a crosslinkable functional group.

  The fluorine-containing polymer having a crosslinkable functional group is obtained by copolymerizing a fluorine-containing monomer and a monomer having a crosslinkable functional group, or by copolymerizing a fluorine-containing monomer and a monomer having a functional group, and then polymer. It can be produced by a method of adding a compound having a crosslinkable functional group to the functional group therein.

  Examples of the fluorine-containing monomer used here include fluoroolefins such as fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, and (meth) acrylic. Examples include acid partial or fully fluorinated alkyl ester derivatives, fully or partially fluorinated vinyl ethers, and the like.

  As a monomer having a crosslinkable functional group or a compound having a crosslinkable functional group, for example, a monomer having a glycidyl group such as glycidyl acrylate or glycidyl methacrylate; a monomer having a carboxyl group such as acrylic acid or methacrylic acid; Monomers having a hydroxyl group such as hydroxyalkyl methacrylate; monomers having an alkenyl group such as allyl acrylate and allyl methacrylate; monomers having an amino group; monomers having a sulfonic acid group.

Examples of the sol material in which inorganic compound fine particles are dispersed in an alcohol solvent include a material containing a sol in which inorganic compound fine particles such as silica, alumina, titania, zirconia, and magnesium fluoride are dispersed in an alcohol solvent. By using the sol material, a low refractive index layer having excellent scratch resistance can be obtained.
The inorganic compound fine particles used for this purpose are preferably those having a smaller refractive index from the viewpoint of antireflection properties. Such inorganic compound fine particles may have voids, and silica hollow fine particles are particularly preferable. The average particle size of the hollow fine particles is preferably in the range of 5 to 2,000 nm, and more preferably in the range of 20 to 100 nm. The average particle diameter here is a number average particle diameter obtained by observation with a transmission electron microscope.

(Anti-fouling layer of acrylic resin film)
The antifouling layer is provided for the purpose of imparting water repellency, oil repellency, sweat resistance, antifouling properties and the like.
Suitable materials for forming the antifouling layer include, for example, fluorine-containing organic compounds such as fluorocarbon, perfluorosilane, and high molecular compounds thereof.
The method for forming the antifouling layer may be appropriately selected according to the material for forming the antifouling layer. For example, physical vapor deposition such as vapor deposition or sputtering; chemical vapor deposition; wet coating Law.
The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

(Anti-glare layer of acrylic resin film)
The antiglare layer is provided for the purpose of improving visibility, preventing reflection of external light, and reducing moire due to interference between the prism sheet and the color filter.
The acrylic resin film of the present invention can be formed as an antiglare film by forming an antiglare layer on the surface thereof. That is, the antiglare film is composed of an acrylic resin film and an antiglare layer having fine surface irregularities formed on the surface thereof. The antiglare layer is a layer having a fine uneven shape on the surface, and is preferably formed from the hard coat material described above.

  As a method for forming an antiglare layer having a fine unevenness on the surface of an acrylic resin film, for example, an organic fine particle or an inorganic fine particle is contained in a coating liquid containing a material for forming the hard coat layer described above, and an acrylic resin film is formed. A method of forming a coating film by coating on the surface of a resin film, and providing irregularities based on the fine particles (hereinafter, sometimes referred to as a fine particle irregularity forming method); Alternatively, the coating liquid containing the material for forming the hard coat layer described above is applied to the surface of the acrylic resin film to form a coating film, and then pressed against a roll having an uneven shape on the surface to transfer the uneven shape. And a method (also called an embossing method).

(Fine particles used for anti-glare treatment of acrylic resin film)
When blending fine particles to form an antiglare layer, the fine particles have an average particle size of 0.5 to 5 μm and a difference in refractive index from the material forming the hard coat layer of 0.02 to 0.2. It is preferable to use a certain one. By using fine particles having an average particle size and a refractive index difference from the material forming the hard coat layer in this range, haze can be effectively expressed. The average particle diameter of the fine particles can be obtained by a dynamic light scattering method or the like. As the average particle size of the fine particles, values obtained from Sekisui Plastics Co., Ltd., Soken Chemical Co., Ltd. and the like were used as they were. This average particle size is the weight average particle size.

Examples of the inorganic fine particles used when forming the antiglare layer include silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate, and the like. .
As the organic fine particles used for forming the antiglare layer, resin particles are generally used. For example, crosslinked polyacrylic acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, and crosslinked polymethyl are used. Examples include methacrylate particles, silicone resin particles, and polyimide particles.

  On the other hand, when forming an antiglare layer having a fine uneven shape on the surface by an embossing method, the mold shape is formed on an acrylic resin film using a mold having a fine uneven shape. It may be transferred to the resin layer. When a fine uneven shape is formed on the surface by an embossing method, the resin layer to which the uneven shape is transferred may or may not contain inorganic or organic fine particles. As a method for transferring the concavo-convex shape by the embossing method, a UV embossing method using an ultraviolet curable resin is preferable.

In the UV embossing method, a UV curable resin layer is formed on the surface of an acrylic resin film, and the UV curable resin layer is cured while being pressed against the rugged surface of the mold. Transferred to the resin layer. Specifically, the ultraviolet curable resin of the acrylic resin film is applied in a state where the ultraviolet curable resin is applied onto the acrylic resin film and the coated ultraviolet curable resin is adhered to the uneven surface of the mold. The ultraviolet curable resin is cured by irradiating ultraviolet rays from the uncoated surface side, and then the acrylic resin film on which the cured ultraviolet curable resin layer is formed is peeled off from the mold. The shape of the mold is transferred to an ultraviolet curable resin.
The ultraviolet curable resin used in the UV embossing method is not particularly limited. For example, one or more polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, and “Irgacure 907”, “ And mixtures with photopolymerization initiators such as “Irgacure 184” (manufactured by Ciba Specialty Chemicals) and “Lucirin TPO” (manufactured by BASF). Further, instead of the ultraviolet curable resin, a visible light curable resin that can be cured with visible light having a wavelength longer than that of ultraviolet light by appropriately selecting a photopolymerization initiator may be used.

  The thickness of the antiglare layer is not particularly limited, and is generally 2 μm or more and 30 μm or less, preferably 3 μm or more, and preferably 20 μm or less. If the thickness of the antiglare layer is thinner than 2 μm, sufficient hardness cannot be obtained and the surface tends to be easily damaged. If it is thicker than 30 μm, it is easy to break or is prevented by the shrinkage of the antiglare layer due to hardening. There is a tendency that the dazzling film curls and the productivity decreases.

  As described above, the antiglare film is provided with haze by the antiglare layer. The haze value is preferably in the range of 1 to 50%. When the haze value is less than 1%, sufficient antiglare performance cannot be obtained, and external light tends to be reflected on the screen. On the other hand, if the haze value exceeds 50%, the reflection of external light can be reduced, but the black display screen is reduced. The haze value is a ratio of diffuse transmittance to total light transmittance, and is measured according to JIS K 7136: 2000 “How to determine haze of plastic-transparent material”.

[Polarizing plate and anti-glare polarizing plate]
The above-described acrylic resin film or the antiglare film provided with the antiglare layer on the acrylic resin film can be bonded to a polarizing film as a protective film to form a polarizing plate.
When bonding an anti-glare film to a polarizing film, a polarizing film is bonded to the surface on the opposite side to the surface where the anti-glare layer was provided. The acrylic resin film or antiglare film of the present invention can be bonded to one surface of the polarizing film, and a protective film made of another resin can be bonded to the other surface of the polarizing film.
Hereinafter, the acrylic resin film or the antiglare film of the present invention may be described as an “optical film”.

(Polarizing film)
The polarizing film is obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based resin film so as to obtain predetermined polarizing characteristics.
As the dichroic dye, for example, iodine or a dichroic organic dye is used. Such polarizing films include an iodine polarizing film in which iodine is adsorbed and oriented on a polyvinyl alcohol resin film, and a dye polarizing film in which a dichroic organic dye is adsorbed and oriented on a polyvinyl alcohol resin film. .

The polyvinyl alcohol resin constituting the polarizing film may be obtained by saponifying a polyvinyl acetate resin and may be modified.
Examples of the polyvinyl acetate resin used for forming the polyvinyl alcohol resin include, for example, polyvinyl acetate, which is a homopolymer of vinyl acetate, and vinyl acetate and other monomers copolymerizable therewith. A copolymer etc. are mentioned.
Examples of other monomers copolymerizable with vinyl acetate used in forming the polyvinyl acetate resin include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, and the like.
Examples of the modified polyvinyl alcohol-based resin include polyvinyl formal resins modified with aldehydes, polyvinyl acetal resins, and polyvinyl butyral resins.

[Production method of polarizing plate]
A polarizing plate is usually manufactured through the following steps.
(i) Humidity adjustment process for adjusting the moisture content of the polyvinyl alcohol resin film
(ii) Stretching process for uniaxially stretching a polyvinyl alcohol-based resin film
(iii) Dyeing process of dyeing polyvinyl alcohol resin film with dichroic dye and adsorbing the dichroic dye
(iv) A boric acid treatment step of treating a polyvinyl alcohol resin film adsorbed and oriented with a dichroic dye with an aqueous solution containing boric acid
(v) After boric acid treatment, washing process to wash off free boric acid adhering to the surface
(vi) Bonding step of bonding the optical film described above as a protective film to a polarizing film on which the steps (i) to (v) are applied and the dichroic dye is adsorbed and oriented. It may be performed during the treatment step, may be performed during the boric acid treatment step, or may be performed during the plurality of steps.

(Humidity adjustment process in the manufacturing method of polarizing plate)
The moisture adjustment of the polyvinyl alcohol resin film is performed, for example, by passing the polyvinyl alcohol resin film through a water tank.

(Drawing process in the manufacturing method of a polarizing plate)
Uniaxial stretching may be performed between rolls having different peripheral speeds, or may be performed using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 4 to 8 times.

(Dyeing process in the manufacturing method of polarizing plate)
The dyeing process is performed, for example, by immersing the polyvinyl alcohol resin film in a dyeing bath containing a dichroic dye.
As the dyeing bath, when iodine is used as a dichroic dye, an aqueous solution containing iodine and potassium iodide is usually used. When a dichroic organic dye is used as a dichroic dye, for example, C . I. Examples include disazo compounds such as DIRECT RED 39; aqueous solutions containing dichroic organic dyes such as trisazo and tetrakisazo compounds.
In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process. Further, the aqueous solution containing the dichroic organic dye may contain an inorganic salt such as sodium sulfate as a dyeing aid.

(Boric acid treatment process in the manufacturing method of a polarizing plate)
The boric acid treatment step is performed by immersing a polyvinyl alcohol-based resin film dyed with a dichroic dye in a boric acid-containing aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

(Washing process in the manufacturing method of a polarizing plate)
In the washing step, the polyvinyl alcohol-based resin film that has undergone the boric acid treatment step described above is washed with water, for example, by immersing it in water, and then dried to obtain a polarizing film.
Examples of the drying method include a method using a hot air dryer, a far infrared heater, and the like.
Although the thickness of the polyvinyl alcohol-type polarizing film which passed through the said process (i)-(v) can be about 1-50 micrometers, for example, Preferably it is about 10-35 micrometers.

(Lamination process in the manufacturing method of a polarizing plate)
Next, the bonding method of the polarizing film subjected to the above steps (i) to (v) and the optical film will be described.
An adhesive is generally used for laminating the polarizing film and the optical film.

Examples of adhesives include solvent-free or solvent-type adhesives that include epoxy resins, urethane resins, cyanoacrylate resins, acrylamide resins, and the like as an adhesive component. The adhesive is preferred.
Solventless adhesives do not contain a significant amount of solvent, and are curable compounds (monomers or oligomers) that are reactively cured by heating or irradiation with active energy rays (for example, ultraviolet rays, visible light, electron beams, X-rays, etc.). The adhesive layer is formed by curing of the curable compound, and typically comprises a curable compound that is reactively cured by heating or irradiation of active energy rays, and a polymerization initiator. The
The solvent-type adhesive contains a significant amount of a solvent such as water, and forms an adhesive layer by heating, for example.

(Solvent-free adhesive used for polarizing film and optical film)
Solventless adhesives include, for example, epoxy adhesives, one-component urethane adhesives, etc. Among them, those that are cured by cationic polymerization are preferable from the viewpoint of reactivity. A solventless epoxy adhesive used as a curable compound is preferably used because it is excellent in adhesiveness between a polarizing film and an optical film made of an acrylic resin or other resin film.

As the epoxy compound that is a curable compound contained in the solvent-free epoxy adhesive, one that is cured by cationic polymerization is preferable. For example, an epoxy compound containing an aromatic ring in the molecule, an aromatic ring contained in the molecule In particular, from the viewpoint of weather resistance, refractive index, etc., it is more preferable to use an epoxy compound that does not contain an aromatic ring in the molecule.
Examples of the epoxy compound containing an aromatic ring in the molecule include an aromatic epoxy compound.
As an epoxy compound which does not contain an aromatic ring in a molecule | numerator, the hydride of an aromatic epoxy compound, an alicyclic epoxy compound, an aliphatic epoxy compound etc. are mentioned, for example.
In addition, the epoxy compound that is a curable compound usually has two or more epoxy groups in the molecule.

  Examples of the aromatic epoxy compound that is an example of an epoxy compound containing an aromatic ring in the molecule include bisphenol type epoxy compounds such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S. ; Novolak type epoxy resin such as phenol novolac epoxy resin, cresol novolac epoxy resin, hydroxybenzaldehyde phenol novolak epoxy resin; Multifunctional type such as glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, epoxidized polyvinylphenol An epoxy resin etc. are mentioned.

A hydride of an aromatic epoxy compound that is an example of an epoxy compound that does not contain an aromatic ring in the molecule will be described.
The hydride of an aromatic epoxy compound is, for example, a nuclear hydrogenated polyhydroxy compound obtained by selectively hydrogenating an aromatic polyhydroxy compound to an aromatic ring in the presence of a catalyst and under pressure, It can be obtained by a method of reacting with epichlorohydrin to glycidyl etherification.
Examples of the aromatic polyhydroxy compound include bisphenols such as bisphenol A, bisphenol F, and bisphenol S; novolac resins such as phenol novolac resin, cresol novolac resin, and hydroxybenzaldehyde phenol novolac resin; tetrahydroxydiphenylmethane, tetrahydroxy Examples include polyfunctional compounds such as benzophenone and polyvinylphenol, and bisphenol A is preferred.

An alicyclic epoxy compound that is an example of an epoxy compound that does not contain an aromatic ring in the molecule will be described.
The alicyclic epoxy compound is an epoxy compound having at least one epoxy group bonded to the alicyclic ring in the molecule, and “having at least one epoxy group bonded to the alicyclic ring in the molecule” Means having a structure represented by the following formula. In formula, m is an integer of 2-5.

Therefore, the alicyclic epoxy compound is a compound having at least one structure represented by the above formula in the molecule and a total of two or more epoxy groups in the molecule including the structure. More specifically, a compound in which one or a plurality of hydrogen atoms in (CH ₂ ) _m in the above formula are bonded to another chemical structure can be an alicyclic epoxy compound. One or more hydrogen atoms in (CH ₂ ) _m may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group. Among such alicyclic epoxy compounds, an epoxy compound having an epoxycyclopentane ring (m = 3 in the above formula) or an epoxycyclohexane ring (m = 4 in the above formula) has high adhesion strength. Since an excellent adhesive is obtained, it is more preferably used.

  Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxyl. Rate, ethylene bis (3,4-epoxycyclohexanecarboxylate), bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, diethylene glycol bis (3,4 Epoxy cyclohexyl methyl ether), ethylene glycol bis (3,4-epoxy cyclohexyl methyl ether), 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispiro- [5.2.2. 5.2 2] Henicosane (This compound is also named 3,4-epoxycyclohexanespiro-2 ′, 6′-dioxanespiro-3 ″, 5 ″ -dioxanespiro-3 ′ ″, 4 ′ ″-epoxycyclohexane. 3- (3,4-epoxycyclohexyl) -8,9-epoxy-1,5-dioxaspiro [5.5] undecane, 4-vinylcyclohexene dioxide, bis-2,3-epoxycyclopentyl ether, di And cyclopentadiene dioxide.

As an aliphatic epoxy compound which is an example of the epoxy compound which does not contain an aromatic ring in a molecule | numerator, the polyglycidyl ether of an aliphatic polyhydric alcohol or its alkylene oxide adduct etc. are mentioned, for example.
Examples of the polyglycidyl ether include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, and polyethylene glycol diglycidyl. Polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide or propylene oxide) to ethers, diglycidyl ethers of propylene glycol, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin And polyglycidyl ether.

  The epoxy compound demonstrated above may be used individually by 1 type, and may be used in combination of 2 or more type.

  The epoxy equivalent of the epoxy compound contained in the solventless epoxy adhesive is usually 30 to 3,000 g / equivalent, preferably 50 to 1,500 g / equivalent. When the epoxy equivalent is less than 30 g / equivalent, the flexibility of the optical film after the adhesive layer is cured may be reduced, or the adhesive strength may be reduced. On the other hand, if the epoxy equivalent exceeds 3,000 g / equivalent, the compatibility with other components contained in the epoxy adhesive may be lowered.

The solventless epoxy adhesive usually contains a cationic polymerization initiator in order to cause the epoxy compound to undergo cationic polymerization.
The cationic polymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, electron beams, or heating, and initiates an epoxy group polymerization reaction. Any of these types of cationic polymerization initiators may be used, but it is preferable from the viewpoint of workability that the potential is imparted.
Hereinafter, a cationic polymerization initiator that initiates an epoxy group polymerization reaction upon irradiation with active energy rays is also referred to as a photocationic polymerization initiator, and a cationic polymerization initiator that initiates an epoxy group polymerization reaction by heating is subjected to thermal cationic polymerization. Also called an initiator.

  Examples of the photocationic polymerization initiator that is an example of a cationic polymerization initiator include aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; iron-allene complexes. These cationic photopolymerization initiators may be used alone or in combination of two or more. Among these, aromatic sulfonium salts are particularly preferable because they have ultraviolet absorption characteristics even in a wavelength region of 300 nm or more, and thus can provide a cured product having excellent curability and good mechanical strength and adhesive strength. Used.

  When the cationic photopolymerization initiator is used, the adhesive component can be cured at room temperature, so there is no need to always consider the heat resistance of the polarizing film or the distortion due to expansion. Can be formed. In addition, when a cationic photopolymerization initiator is used, it acts catalytically by light, so that it is excellent in storage stability and workability even when mixed with an epoxy adhesive.

  As commercial products of these photocationic polymerization initiators, for example, “Kayarad PCI-220” and “Kayarad PCI-620” and Union Carbide, both sold under the trade name, Nippon Kayaku Co., Ltd. "UVI-6990" sold by ADEKA Corporation, "Adekaoptomer SP-150" and "Adekaoptomer SP-170" sold by ADEKA, "CI" sold by Nippon Soda Co., Ltd. -5102 "," CIT-1370 "," CIT-1682 "," CIP-1866S "," CIP-2048S "and" CIP-2064S "," DPI-101 "sold by Midori Chemical Co., Ltd. "DPI-102", "DPI-103", "DPI-105", "MPI-103", "MPI-105", "BBI-101", "BBI-102", "BBI-10 "," BBI-105 "," TPS-101 "," TPS-102 "," TPS-103 "," TPS-105 "," MDS-103 "," MDS-105 "," DTS-102 "and “DTS-103”, “PI-2074” sold by Rhodia, and the like.

  The compounding quantity of a photocationic polymerization initiator is 0.5-20 weight part normally with respect to 100 weight part of epoxy compounds, Preferably it is 1 weight part or more, Preferably it is 15 weight part or less.

The solventless epoxy adhesive can contain a photosensitizer as necessary in addition to the photocationic polymerization initiator. By using a photosensitizer, the reactivity is improved and the mechanical strength and adhesive strength of the cured product can be improved.
Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreductive dyes. When mix | blending a photosensitizer, the quantity is about 0.1-20 weight part with respect to 100 weight part of epoxy compounds.

  Examples of the thermal cationic polymerization initiator that is an example of the cationic polymerization initiator include benzylsulfonium salt, thiophenium salt, thiolanium salt, benzylammonium salt, pyridinium salt, hydrazinium salt, carboxylic acid ester, sulfonic acid ester, and amine imide. It is done.

  Examples of commercial products of these thermal cationic polymerization initiators are “Adeka Opton CP77” and “Adeka Opton CP66” sold by ADEKA Co., Ltd., and Nippon Soda Co., Ltd. “CI-2639” and “CI-2624”, “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L” and the like sold by Sanshin Chemical Industry Co., Ltd. can be mentioned. These thermal cationic polymerization initiators may be used alone or in combination of two or more. Moreover, a photocationic polymerization initiator and a thermal cationic polymerization initiator can be used in combination.

  The solventless epoxy adhesive may further contain a compound that promotes cationic polymerization, such as oxetanes and polyols.

(Bonding method of polarizing film and optical film using solventless adhesive)
When a solventless epoxy adhesive is used, the polarizing film and the optical film can be bonded by applying the adhesive to the adhesive surface of the optical film and / or the polarizing film and bonding them together. .
The method for applying a solventless epoxy adhesive to the polarizing film and / or optical film is not particularly limited, and various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater are available. Construction method can be used. Moreover, since each coating method has an optimum viscosity range, the viscosity may be adjusted using a small amount of solvent. The solvent used for this is not particularly limited as long as it can dissolve the epoxy adhesive well without degrading the optical performance of the polarizing film. For example, hydrocarbons such as toluene, esters such as ethyl acetate, etc. Organic solvents can be used.

After bonding the optical film to the polarizing film through an adhesive layer made of an uncured epoxy adhesive, the adhesive layer is cured by irradiating active energy rays or heating, and optical The film is fixed on the polarizing film. In the case of curing by irradiation with active energy rays, ultraviolet rays are preferably used.
Examples of the ultraviolet light source include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a black light lamp, and a metal halide lamp.
The irradiation intensity and irradiation amount of active energy rays such as ultraviolet rays are appropriately selected so as to sufficiently activate the cationic photopolymerization initiator and not adversely affect the cured adhesive layer, polarizing film, and optical film. . Further, when cured by heating, it can be heated by a generally known method, and the temperature and time at that time sufficiently activate the thermal cationic polymerization initiator, and the cured adhesive layer In addition, it is appropriately selected so as not to adversely affect the polarizing film and the optical film.

  The thickness of the adhesive layer made of the epoxy adhesive after curing obtained as described above can usually be in the range of about 0.1 to 50 μm, preferably 1.0 μm or more. Moreover, it is more preferable that it exists in the range of 1.0-20 micrometers, and it is further more preferable that it exists in the range of 1.0-10 micrometers.

  The solvent-free epoxy adhesive described above is bonded between an optical film made of an acrylic resin and a polarizing film, or bonded between an optical film made of a resin film other than an acrylic resin and a polarizing film, or these It can use preferably for pasting of both.

(Solvent adhesive used for bonding of polarizing film and optical film)
Examples of the solvent-type adhesive include water-based adhesives.
Examples of the water-based adhesive include those obtained by dissolving an adhesive component in water, or those obtained by dispersing this in water. When a water-based adhesive is used, the thickness of the adhesive layer can be further reduced.
Examples of the adhesive component of the water-based adhesive include a water-soluble crosslinkable epoxy resin and a hydrophilic urethane resin.

Examples of water-soluble crosslinkable epoxy resins that are examples of water-based adhesives include, for example, polychloropolyamines obtained by reaction of polyalkylenepolyamines such as diethylenetriamine and triethylenetetramine with dicarboxylic acids such as adipic acid, and epichlorohydride. Examples thereof include polyamide epoxy resins obtained by reacting phosphorus.
Examples of such a commercially available product of polyamide epoxy resin include “Smileys Resin 650” and “Smileys Resin 675” sold by Sumika Chemtex Co., Ltd., all of which are trade names.

  When a water-soluble crosslinkable epoxy resin is used as the adhesive component, it is preferable to mix other water-soluble resins such as a polyvinyl alcohol-based resin in order to further improve coatability and adhesiveness.

  Examples of polyvinyl alcohol resins include partially saponified polyvinyl alcohol; completely saponified polyvinyl alcohol; carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol. Among them, a saponified product of a copolymer of vinyl acetate and an unsaturated carboxylic acid or a salt thereof, that is, a carboxyl group-modified polyvinyl alcohol is preferably used. Here, the “carboxyl group” is a concept including —COOH and a salt thereof.

  As commercial products of carboxyl group-modified polyvinyl alcohol, all are trade names, and “Kuraraypoval KL-506”, “Kuraraypoval KL-318” and “Kuraraypoval KL-118” sold by Kuraray Co., Ltd., "GOHSENAL T-330" and "GOHSENAL T-350" sold by Nippon Synthetic Chemical Industry Co., Ltd., "DR-0415" sold by Denki Kagaku Kogyo Co., Ltd. "AF-17", "AT-17", and "AP-17" sold by the company).

  The adhesive containing a water-soluble crosslinkable epoxy resin can be prepared as an aqueous adhesive solution by dissolving the above epoxy resin and other water-soluble resin such as a polyvinyl alcohol resin added as necessary in water. In this case, the concentration of the water-soluble crosslinkable epoxy resin is preferably about 0.2 to 2 parts by weight with respect to 100 parts by weight of water. Moreover, when mix | blending polyvinyl alcohol-type resin, the quantity is about 1-10 weight part with respect to 100 weight part of water, Furthermore, it is preferable to set it as about 1-5 weight part.

On the other hand, examples of hydrophilic urethane resins that are examples of water-based adhesives include ionomer-type urethane resins. Among these, polyester ionomer-type urethane resins are preferable. Here, the ionomer type is obtained by introducing a small amount of an ionic component (that is, a hydrophilic component) into a urethane resin constituting the skeleton. The polyester ionomer type urethane resin is a urethane resin having a polyester skeleton, in which a small amount of an ionic component (hydrophilic component) is introduced, and directly in water without using an emulsifier. Since it is emulsified into an emulsion, it is suitably used as an aqueous adhesive.
Examples of commercially available polyester-based ionomer-type urethane resins include “Hydran AP-20” and “Hydran APX-101H” sold by DIC Corporation under the trade name. Available in form.

  When an ionomer type urethane resin is used as the adhesive component, it is preferable to further blend an isocyanate-based crosslinking agent.

The isocyanate-based crosslinking agent is a compound having at least two isocyanato groups (—NCO) in the molecule. For example, 2,4-tolylene diisocyanate, phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,6-hexa Polyisocyanate monomers such as methylene diisocyanate and isophorone diisocyanate; Adducts in which multiple molecules of polyisocyanate monomers are added to polyhydric alcohols such as trimethylolpropane; Trifunctional isocyanurate having a nurate ring; modified polyisocyanate such as a buret formed by hydration and decarboxylation of three diisocyanate molecules at each isocyanato group. It is.
As a commercial item of an isocyanate type crosslinking agent, what is marketed by the brand name of "Hydran Assister C-1" from DIC Corporation is mentioned, for example.

  When an aqueous adhesive containing an ionomer type urethane resin is used, the concentration of the urethane resin is about 10 to 70% by weight, further 20% by weight or more, and 50% by weight or less from the viewpoint of viscosity and adhesiveness. Thus, those dissolved or dispersed in water are preferred. When the isocyanate crosslinking agent is blended, the blending amount is appropriately selected so that the isocyanate crosslinking agent is about 5 to 100 parts by weight with respect to 100 parts by weight of the urethane resin.

(Paste method of polarizing film and optical film using solvent type adhesive)
When such a water-based adhesive is used, the polarizing film and the optical film can be adhered by applying the adhesive to the adhesive surface of the optical film and / or the polarizing film and bonding them together. More specifically, a water-based adhesive is uniformly applied to a polarizing film and / or an optical film by, for example, a coating method such as a doctor blade, a wire bar, a die coater, a comma coater, or a gravure coater. The other film is stacked and bonded with a roll or the like and dried.
Drying can be performed at a temperature of about 60 to 100 ° C., for example. In order to further improve the adhesiveness, it is preferable to cure for about 1 to 10 days after drying at a temperature slightly higher than room temperature, for example, a temperature of about 30 to 50 ° C.

  These water-based adhesives are bonded to an optical film made of an acrylic resin and a polarizing film, or polarized with an optical film made of a resin other than an acrylic resin, like the solventless epoxy adhesive described above. It can use preferably for pasting with a film, or pasting of both of these. When an optical film made of an acrylic resin is laminated on both surfaces of a polarizing film, an optical film made of an acrylic resin is laminated on one surface of the polarizing film, and an optical film made of a resin other than an acrylic resin is laminated on the other surface In any case of laminating a film (including the case of being a retardation film such as a wave plate or a viewing angle compensation film, the same applies hereinafter), the same adhesive is used for adhering films laminated on both sides of the polarizing film. Alternatively, different adhesives may be used, but it is preferable to use the same adhesive in order to simplify the manufacturing process and reduce the number of constituent members of the polarizing plate.

(Surface treatment when laminating polarizing film and optical film)
In the production of the polarizing plate, it is preferable to perform corona discharge treatment on the surface of the optical film made of acrylic resin and the optical film made of resin other than acrylic resin that is bonded to the polarizing film. By performing the corona discharge treatment, the adhesive force between these films and the polarizing film can be increased. The corona discharge treatment is a treatment for activating the resin film disposed between the electrodes by discharging by applying a high voltage between the electrodes. The effect of the corona discharge treatment varies depending on the type of electrode, electrode interval, voltage, humidity, type of resin film used, etc., for example, the electrode interval is set to 1 to 5 mm, and the moving speed is set to about 3 to 20 m / min. It is preferable to do this. After the corona discharge treatment, a polarizing film is bonded to the treated surface via the adhesive as described above.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited by these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified.

The structure of the extrusion apparatus used in the following examples and comparative examples is as follows.
Extruder 1: Vented screw diameter 130 mmφ uniaxial extruder T die 2: T die with a die width of 1650 mm Cutting unit 6: Upper round blade 6a and lower round blade 6b each having a diameter of 150 mm

  The extruder 1, the T die 2, the first to third cooling rolls 3 to 5, and the cutting unit 6 are arranged as shown in FIG. 1, and the cooling rolls 3 to 5 are configured as follows.

<Roll configuration>
The 1st-3rd cooling rolls 3-5 were comprised as follows.
First cooling roll 3: A 2 mm thick stainless steel thin film with one side mirrored so as to cover the outer periphery of the shaft roll made of stainless steel is arranged so that the mirror-finished surface becomes the roll outer surface, and the shaft roll Metal elastic roll in which a fluid made of heat transfer oil is sealed between a metal thin film and a second thin film roll. A metal roll made of stainless steel with a mirror-finished surface. A third cooling roll 5: a shaft roll made of stainless steel. A stainless steel thin film with a thickness of 2 mm with one side mirrored so as to cover the outer peripheral portion is arranged so that the mirror-finished surface is the outer surface of the roll, and is composed of a heat transfer oil between the shaft roll and the metallic thin film. Metal elastic roll filled with fluid

Example 1
<Production of acrylic resin>
As the methacrylic resin, pellets of a thermoplastic polymer (glass transition temperature 104 ° C.) polymerized using methyl methacrylate and a small amount of methyl acrylate were used.
Acrylic rubber particles produced according to Example 3 of JP-B-55-27576, the innermost layer being a hard polymer polymerized using methyl methacrylate and a small amount of allyl methacrylate, and the intermediate layer being acrylic acid Spherical three-layer structure consisting of butyl as a main component and further polymerized with styrene and a small amount of allyl methacrylate, and outermost layer composed of a hard polymer polymerized with methyl methacrylate and a small amount of methyl acrylate The average particle diameter was 0.22 μm. In addition, the average particle diameter of the acrylic rubber particles is obtained by mixing the acrylic rubber particles with a methacrylic resin to form a film, staining the elastic polymer (intermediate layer) with ruthenium oxide in the cross section, and observing with an electron microscope. It calculated | required from the diameter of the dye | stained part.
70 parts of thermoplastic polymer pellets and 30 parts of acrylic rubber particles were mixed with a super mixer, melt-kneaded with a twin screw extruder to form pellets, and this was used as an acrylic resin.

<Production of acrylic resin film>
The acrylic resin obtained above is melt-kneaded by a 130 mmφ single screw extruder 1, the sheet-like material 10 is extruded from the T-die 2, and the sheet-like material 10 is placed between the first cooling roll 3 and the second cooling roll 4. The film-shaped molded body 11 was obtained by being sandwiched and wound around the third cooling roll 5. When the length of the obtained film-shaped molded object 11 in the width direction was measured, it was 1540 mm at the maximum and 1520 mm at the minimum.
Next, both end portions of the film-shaped molded body 11 are formed so that the length in the width direction becomes 1330 mm by the upper and lower round blades 6a and 6b arranged in a pair of upper and lower ends on both side ends of the film-shaped molded body 11. Was cut to obtain an acrylic resin film 12. When the thickness of this acrylic resin film 12 was measured, it was 80 μm.

<Preparation of antiglare film>
Contains 60 parts of pentaerythritol triacrylate and 40 parts of polyfunctional urethanized acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) and dissolves ethyl acetate so that the total concentration of both is 60% Then, a leveling agent was further blended to prepare a photocurable resin composition. Hereinafter, the pentaerythritol triacrylate and the polyfunctional urethanized acrylate constituting the photocurable resin composition are collectively referred to as “curable acrylate”.
To 100 parts of the curable acrylate in the photocurable resin composition, 5 parts of methyl methacrylate / styrene copolymer resin particles having an average particle size of 2.7 μm are added and dispersed. Further, the curable acrylate and the resin particles are dispersed. Diluted with ethyl acetate to a total concentration of 30%. Thereafter, 1 part of “Irgacure 184” (manufactured by Ciba) as a photopolymerization initiator was added to 100 parts of the curable acrylate in the liquid to prepare a coating liquid for forming an antiglare layer.

  The resin obtained by adding the above photopolymerization initiator to the photocurable resin composition used here to form a film and cured by irradiation with ultraviolet rays has a refractive index of 1.53, while the above methyl methacrylate / The refractive index of the styrene copolymer resin particles was 1.49. Therefore, the refractive index difference between the two was 0.04.

In the drier set to 60 ° C., the coating solution for forming the antiglare layer prepared above was applied to one surface of the acrylic resin film 12 so that the coating thickness after drying was 3.4 μm. Held for 3 minutes to dry the coating. After drying, the surface on which the coating film of the acrylic resin film 12 is formed is irradiated with light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² so that the amount of light converted to h-ray is 200 mJ / cm ^2. The coating layer of the composition was cured to obtain an antiglare film in which an antiglare layer having irregularities was formed on the surface of the acrylic resin film. The obtained antiglare film was wound up on a 6-inch diameter core.
When the haze value of the antiglare film was measured using a haze meter, the haze value was 11.5%.

<Preparation of polarizing plate>
The antiglare film obtained above is applied to one surface of a polarizing film having a thickness of about 30 μm in which iodine is adsorbed and oriented on polyvinyl alcohol, and an adhesive (Toagosei ( Pasted through “Aronix” manufactured by Co., Ltd.), and a cycloolefin-based resin film on the other surface of the polarizing film, via an adhesive (“Adekaoptomer KR Series” manufactured by ADEKA) Bonding was performed to obtain a polarizing plate.

<Manufacture of an adhesive composition>
In a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer, 81.8 parts of ethyl acetate, 78.8 parts of butyl acrylate, 20 parts of methyl acrylate, 1.0 part of 2-hydroxyethyl acrylate and A mixed solution of 0.2 part of acrylic acid was charged, and the internal temperature was raised to 55 ° C. while replacing the air in the apparatus with nitrogen gas so as not to contain oxygen. Thereafter, a total amount of a solution prepared by dissolving 0.14 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. One hour after adding the initiator, while adding ethyl acetate continuously into the reaction vessel at an addition rate of 17.3 parts / hour so that the concentration of the acrylic resin excluding the monomer was 35%, the internal temperature The mixture was kept at 54 to 56 ° C. for 12 hours, and finally ethyl acetate was added to adjust the concentration of the acrylic resin to 20%. The obtained acrylic resin had a weight average molecular weight (Mw) in terms of polyethylene by gel permeation chromatography (GPC) of 1,512,000.
With respect to 100 parts of the solid content of the obtained acrylic resin, 3.0 parts of the ionic compound, 0.5 part of the silane compound, and 0.6 part of the crosslinking agent are mixed, and the solid content concentration is 13%. Ethyl acetate was added so that an adhesive composition was obtained.

架橋剤：ヘキサメチレンジイソシアネートのイソシアヌレート体（日本ポリウレタン（株）製の「コロネート ＨＸＲ」）
シラン系化合物：グリシドキシプロピルトリメトキシシラン（液体）（信越化学工業（株）製の「ＫＢＲ−４０３」） In addition, said ionic compound, a crosslinking agent, and a silane type compound are as follows.
Ionic compound: N-octyl-4-methylpyridinium hexafluorophosphate (melting point: 44 ° C., see chemical formula below)

Cross-linking agent: Isocyanurate of hexamethylene diisocyanate ("Coronate HXR" manufactured by Nippon Polyurethane Co., Ltd.)
Silane compound: Glycidoxypropyltrimethoxysilane (liquid) (“KBR-403” manufactured by Shin-Etsu Chemical Co., Ltd.)

<Preparation of sample for evaluation>
After drying the pressure-sensitive adhesive composition obtained above on the release treatment surface of a release-treated polyethylene terephthalate film ("PLR382051" manufactured by Lintec Corporation, hereinafter sometimes referred to as a separator) using an applicator Was applied at a thickness of 20 μm and dried at 100 ° C. for 1 minute to obtain a sheet-like pressure-sensitive adhesive having a pressure-sensitive adhesive layer on one side of the separator. Next, after laminating the sheet-like pressure-sensitive adhesive on the cycloolefin-based resin film surface of the polarizing plate obtained above so that the pressure-sensitive adhesive layer surface becomes the bonding surface, the temperature is 23 ° C. and the relative humidity is 65%. The film was cured under conditions for 7 days to obtain a polarizing plate with an adhesive.
Next, the obtained polarizing plate with the pressure-sensitive adhesive was cut into a size of the length in the width direction × the length in the flow direction = 250 mm × 300 mm, and the separator was peeled off from the cut out polarizing plate with the pressure-sensitive adhesive layer, It was made to be the outermost surface. Next, as a surface for bonding the adhesive layer in the cut polarizing plate with the adhesive to a glass plate having a size in the width direction × length in the flow direction × thickness = 270 mm × 320 mm × 0.8 mm. In combination, a sample for evaluation was produced.

(Example 2)
Acrylic resin film was obtained in the same manner as in Example 1 except that the extrusion apparatus and the like were adjusted so that the length in the width direction of the film-shaped molded product was 1540 mm at the maximum and 1505 mm at the minimum. A polarizing plate and a sample for evaluation were obtained in the same manner as in Example 1 using a resin film.

(Example 3)
Acrylic resin film was obtained in the same manner as in Example 1 except that the extrusion device and the like were adjusted so that the length in the width direction of the film-shaped molded body was 1565 mm at the maximum and 1445 mm at the minimum. A polarizing plate and a sample for evaluation were obtained in the same manner as in Example 1 using a resin film.

(Comparative Example 1)
Acrylic resin film was obtained in the same manner as in Example 1 except that the extrusion apparatus and the like were adjusted so that the length in the width direction of the film-shaped molded product was 1580 mm at the maximum and 1390 mm at the minimum. A polarizing plate and a sample for evaluation were obtained in the same manner as in Example 1 using a resin film.

(Comparative Example 2)
Acrylic resin film was obtained in the same manner as in Example 1 except that the extrusion apparatus and the like were adjusted so that the length in the width direction of the film-shaped molded product was 1585 mm at the maximum and 1390 mm at the minimum, and the obtained acrylic resin was obtained. A polarizing plate and a sample for evaluation were obtained in the same manner as in Example 1 using a resin film.

(Comparative Example 3)
Acrylic resin film was obtained in the same manner as in Example 1 except that the extrusion apparatus and the like were adjusted so that the length in the width direction of the film-shaped molded product was 1580 mm at the maximum and 1385 mm at the minimum. A polarizing plate and a sample for evaluation were obtained in the same manner as in Example 1 using a resin film.

  The following evaluation was performed about each obtained film. The results are shown in Table 2.

<Length in the direction (width direction) orthogonal to the flow direction of the film-like molded body>
After being wound around the third cooling roll 5, during film formation before the film-shaped molded body is trimmed by the cutting unit 6, measurement is performed 10 times every 10 seconds with a measuring tool, and out of 10 times measured The maximum and minimum values were obtained.

<Thickness of acrylic resin film>
The acrylic resin film was divided into 10 equal parts in the width direction and further divided into 6 equal parts in the flow direction, the thickness of the central part of the square was measured with a micrometer, and the average value of the measured 60 points was calculated.

<Thickness accuracy of acrylic resin film>
(Film flow direction)
The obtained acrylic resin film (length in the flow direction × length in the width direction = 1500 mm × 1330 mm) was equally divided into 10 in the width direction, and the first, fifth, and tenth rows were measured samples (flow). The length in the direction × the length in the width direction = 1500 mm × 133 mm). The measurement sample was measured at 24 points at intervals of 50 mm in the flow direction using a micrometer. The measurement results are shown in Table 1. Of the values calculated by the following formulas (A) and (B) from the maximum and minimum values of the measured thickness and the measured average thickness of 24 points, the larger value is the thickness accuracy in the flow direction. did.
[(Maximum value−average value) / average value] × 100 (A)
[(Average value−minimum value) / average value] × 100 (B)

(Film width direction)
From the obtained resin film (length in the flow direction × length in the width direction = 1500 mm × 1330 mm), a strip-shaped sample having a length in the flow direction of 50 mm (length in the flow direction × length in the width direction = 50 mm) × 1330 mm) was cut out. Using a micrometer, the thickness of the strip-shaped sample was measured at 54 points at intervals of 25 mm in the width direction. The results are shown in Table 1. In addition, it was set as the larger value among the values calculated by the said (A) type | formula or (B) type | formula from the measured maximum value and minimum value, and the average value of 54 points | pieces measured.

<Crack resistance>
A heat cycle test was performed in which a heat cycle in which the sample for evaluation was left in a 70 ° C. environment for 1 hour and then left in a −35 ° C. environment for 1 hour was repeated 120 times.
After the heat cycle test, the evaluation sample was visually observed, and the evaluation sample in which generation of cracks was not confirmed was evaluated as “◯”. When the occurrence of cracks is confirmed in the evaluation sample, the light from the fluorescent lamp is irradiated with crossed Nicols using the evaluation sample in which the occurrence of cracks is confirmed and the evaluation sample not subjected to the heat cycle test. If there is no light leakage, that is, if it can be confirmed that fine cracks are generated in the evaluation sample subjected to the heat cycle test, “△”, if light leakage is observed, that is, the evaluation sample. When it was confirmed that remarkable cracks were generated, the evaluation sample was evaluated as “×”.

<Adhesiveness>
The sample for evaluation was left in an oven set at 80 ° C. for 1500 hours. Next, after the temperature in the oven was brought to room temperature, the evaluation sample was taken out of the oven. When the sample for evaluation after taking out from the oven is visually observed, the case where the polarizing plate peels 3 mm or more from the edge of the glass plate is “x”, and the case where the polarizing plate peels 1 mm or more and less than 3 mm from the edge of the glass plate “Δ” was evaluated as “◯” when the polarizing plate was peeled off from the edge of the glass plate by more than 0 mm and less than 1 mm, and “◎” when the polarizing plate was not peeled off from the edge of the glass plate.

As shown in Table 1, in Examples 1 to 3, the thickness accuracy of the acrylic resin film in the flow direction is within 3% even at the side edges in the width direction (measurement samples in the first and tenth rows). In addition, since the thickness accuracy in the width direction was within 2%, the thickness accuracy was high in both the flow direction and the width direction. On the other hand, in Comparative Examples 1 and 3, the side end portions in the width direction (measurement samples in the first and tenth rows) were within 3%, but the thickness accuracy in the width direction was 2% or more. In Comparative Example 2, even the central portion (measurement sample in the fifth row) in the width direction was 3% or more, but the thickness accuracy in the width direction was 2% or less, so the flow direction or width direction The thickness accuracy of was low.
Moreover, as shown in Table 2, Examples 1-3 were excellent in the crack resistance of a polarizing plate, and the adhesiveness of the sample for evaluation.

DESCRIPTION OF SYMBOLS 1 Extruder 2 T die 3 1st cooling roll 4 2nd cooling roll 5 3rd cooling roll 6 Cutting unit 6a Upper round blade 6b Lower round blade 10 Film-like thing 11 Film-like molded object 12 Acrylic resin film

Claims (7)

Acrylic resin is melt-kneaded, a film-like product is extruded from a T-die, and the film-like product is sandwiched between a first cooling roll and a second cooling roll to form a film-like molded product, and the film-like molding An acrylic resin film obtained by cutting the side end of the body,
The acrylic resin film, wherein the acrylic resin film has a thickness accuracy of 3% or less in the flow direction and a thickness accuracy of 2% or less in a direction perpendicular to the flow direction. The width of the film-shaped molded body (W _f ) in the direction orthogonal to the flow direction of the film-shaped molded body and the die width (W _d ) of the T die are 0.85 ≦ W _f / W _d ≦ 0.95. The acrylic resin film according to claim 1 satisfying the relationship: The acrylic resin film width (W) in the direction perpendicular to the flow direction of the acrylic resin film and the film-like molded body width (W _f ) in the direction perpendicular to the flow direction of the film-like molded body are 0. acrylic resin film according to claim 1 or 2 satisfying the relation of _{70 ≦ W / W f ≦ 0.90} .   The acrylic resin film according to claim 1, wherein the acrylic resin contains rubber particles.   A polarizing plate comprising the acrylic resin film according to claim 1 bonded to a polarizing film. Acrylic resin is melt-kneaded, a film-like product is extruded from a T-die, and the film-like product is sandwiched between a first cooling roll and a second cooling roll to form a film-like molded product, and the film-like molding A method for producing an acrylic resin film by cutting a side end of a body,
The die width (W _d ) of the T die and the film-like formed body width (W _f ) in the direction orthogonal to the flow direction of the film-like formed body are 0.85 ≦ W _f / W _d ≦ 0. 95. A method for producing an acrylic resin film, wherein the relationship of 95 is satisfied. The film-shaped molded body width (W _f ) in the direction orthogonal to the flow direction of the film-shaped molded body and the acrylic resin film width (W) in the direction orthogonal to the flow direction of the acrylic resin film are 0.00. the process according to claim 6 satisfying the relation of _{70 ≦ W / W f ≦ 0.90} .

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