JP2018013583A - Optical film having separator film laminate adhesive layer - Google Patents

Abstract

An object of the present invention is to provide an optical film with a separator film laminate pressure-sensitive adhesive layer, which is less likely to cause streak-like wrinkles in the separator film and the pressure-sensitive adhesive layer under the chip when cut into chips. To do. An optical film with a separator film laminated pressure-sensitive adhesive layer comprising a separator film (C) laminated on at least one surface of an optical film (A) via a pressure-sensitive adhesive layer (B), the separator film An optical film with a separator film laminate pressure-sensitive adhesive layer, wherein the film thickness of (C) is 45 μm or more and the creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is 3N or more. [Selection figure] None

Description

  The present invention relates to an optical film with a separator film laminated adhesive layer obtained by laminating a separator film on an optical film with an adhesive layer.

  An optical film typified by a polarizing plate obtained by laminating and laminating a transparent resin film on one or both surfaces of a polarizer is widely used as an optical member constituting an image display device such as a liquid crystal display device. In many cases, an optical film such as a polarizing plate or a retardation plate is configured as an optical film with an adhesive layer in which an adhesive layer is provided on one surface, and a liquid crystal cell or an organic film is formed through the adhesive layer. It is often used by being bonded to a display element such as an EL display element. In such an optical film with an adhesive layer, in order to protect the adhesive layer before being bonded to the display element, usually, the adhesive layer is left on the optical film side when the adhesive layer is used. A separator film is laminated (Patent Document 1).

International Publication No. 2009/069799 Pamphlet

  In recent years, there has been a tendency to reduce the thickness of image display devices. For this reason, a thinner optical film is desired, such as 100 μm or less. In such an optical film with a separator film laminated adhesive layer in which an adhesive layer is provided on a thin optical film and a separator film is laminated thereon, when the film is cut into, for example, a rectangular chip, Very small streak-like wrinkles may occur in the separator film and the pressure-sensitive adhesive layer therebelow. The streak-like wrinkles generated in this way may move to the inside (center part) of the chip. In this way, when extremely small streak-like wrinkles gather at the center, they become conspicuous as defects.

  Accordingly, an object of the present invention is to provide an optical film with a separator film laminated pressure-sensitive adhesive layer in which very small wrinkles are not easily generated in the separator film and the pressure-sensitive adhesive layer below the chip when cut into chips. And

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the present invention includes the following preferred modes [1] to [4].
[1] An optical film with a separator film laminated pressure-sensitive adhesive layer comprising a separator film (C) laminated on at least one surface of the optical film (A) via a pressure-sensitive adhesive layer (B),
An optical film with a separator film laminated pressure-sensitive adhesive layer, wherein the separator film (C) has a film thickness of 45 μm or more, and a creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is 3N or more.
[2] The optical film with the separator film laminated pressure-sensitive adhesive layer according to [1], wherein the bending stiffness of the separator film (C) is 1 mg or more.
[3] The optical film with a separator film laminated pressure-sensitive adhesive layer according to [1] or [2], wherein the optical film (A) has a water absorption rate of 2.0% or more.
[4] The optical film with a separator film laminated pressure-sensitive adhesive layer according to any one of [1] to [3], wherein the optical film (A) has a thickness of 100 μm or less.

  ADVANTAGE OF THE INVENTION According to this invention, when cut out to a chip | tip etc., the separator film and the optical film with a separator film lamination adhesive layer which cannot produce a wrinkle-like wrinkle easily in an adhesive layer under it can be provided.

FIG. 1 is a schematic sectional view showing an example of an optical film with a separator film laminated pressure-sensitive adhesive layer according to the present invention. FIG. 2 is a schematic cross-sectional view showing an example of an optical film with a separator film laminated pressure-sensitive adhesive layer according to the present invention. FIG. 3 is a schematic top view and a schematic cross-sectional view of a sample for measuring the creep force of an optical film with a separator film laminated pressure-sensitive adhesive layer.

<Optical film with separator film laminated adhesive layer>
The separator film laminated optical film with a pressure-sensitive adhesive layer of the present invention is an optical film (A) and a separator film (C) laminated on at least one surface of the optical film (A) via a pressure-sensitive adhesive layer (B). including.

  In the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention, the film thickness of the separator film (C) is 45 μm or more. When the film thickness of the separator film is less than 45 μm, extremely small stripes and wrinkles are likely to occur in the separator film and the pressure-sensitive adhesive layer therebelow. In the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention, the thickness of the separator film (C) is preferably 47 μm or more. Although the upper limit of the film thickness of a separator film (C) is not specifically limited, Usually, it is 200 micrometers or less, and since it is easy to raise when peeling a separator film from an adhesive layer, for example, It is preferably 150 μm or less, and more preferably 100 μm or less.

  In the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention, the creep force (also referred to as creep force) at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is 3N or more. If the creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is less than 3N, the pressure-sensitive adhesive force between the separator film (C) and the pressure-sensitive adhesive layer (B) is weak, and the optical film is cut into chips. When this happens, very small streak-like wrinkles are likely to occur from the end. In addition, since a gap is easily formed between the separator film and the pressure-sensitive adhesive layer, the separator film easily slips from the pressure-sensitive adhesive layer, and accordingly, streaks are likely to advance into the chip. In the optical film with a separator film laminated pressure-sensitive adhesive layer of the present invention, the creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is preferably 4N or more. The upper limit of the creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is not particularly limited, but is usually 15 N or less, and is caused when the separator film is peeled off from the pressure-sensitive adhesive layer. For example, it is preferably 12N or less, and more preferably 10N or less from the viewpoint of facilitating the process. The creep force is a value measured according to the method described in the examples.

  The creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) can be controlled to a desired value by, for example, the peeling force of the separator film with respect to the pressure-sensitive adhesive layer, the elastic modulus of the peeling layer, or the like. Specifically, for example, the creep force can be increased by increasing the peeling force or the elastic modulus of the peeling layer.

  Here, in the present invention, the optical film refers to a film that functions for image display (display screen or the like) (for example, a film that functions to improve the visibility of an image), such as a liquid crystal display device. It means a film having various optical properties that can be incorporated into an image display device. For example, a single layer structure (for example, a polarizer, a retardation film, a brightness enhancement film, an antiglare film, an antireflection film, a diffusion film, a light collecting film) Etc.) or a multilayer structure (for example, a polarizing plate, a phase difference plate, etc.). When the optical film has a multilayer structure, a layer (for example, a protective film) finally peeled and removed when the optical film is incorporated into an optical laminate or a display device is used in the present invention. ) Is not considered.

  The separator film laminated optical film with a pressure-sensitive adhesive layer of the present invention is an optical film (A) and a separator film (C) laminated on at least one surface of the optical film (A) via a pressure-sensitive adhesive layer (B). As long as the optical film is configured to have a function normally included as an optical film, the configuration is not limited. As the optical film, a polarizing plate, a polarizer, a retardation plate or a retardation film is preferable, and a polarizing plate or a polarizer is particularly preferable.

  For example, the configuration in one preferred embodiment of the present invention will be described with reference to FIG. 1 and FIG. 2. An optical film 1 with a separator film laminated adhesive layer shown in FIG. 1 includes an optical film 10 and the optical film. The separator film 30 is laminated on one side with the adhesive layer 20 interposed therebetween. Further, the optical film 10 is formed by laminating resin films 3 and 4 on both sides of the polarizer 2, and protects the surface of the resin film 4 on the opposite side of the resin film 4 having the adhesive layer 20 on the surface not in contact with the polarizer 2. A film 5 is laminated. Moreover, the optical film 1 with a separator film lamination adhesive layer shown by FIG. 2 is comprised from the optical film 10 and the separator film 30 laminated | stacked through the adhesive layer 20 on the single side | surface of this optical film. The resin film 3 and 4 are laminated | stacked on both sides of the polarizer 2, and the hard-coat layer 6 is provided in the surface which does not touch the polarizer 2 of the resin film 4 on the opposite side to the resin film which has the adhesive layer 20. FIG. ing. Further, a protective film 5 is laminated on the hard coat layer 6. In addition, the resin films 3 and 4 can be bonded to the polarizer 2 through an adhesive layer or an adhesive layer (not shown).

  Each layer (member) which comprises the optical film with a separator film laminated adhesive layer of this invention is not specifically limited, What is necessary is just to determine suitably according to the characteristic etc. of the desired optical film. Hereinafter, the suitable aspect is demonstrated in detail about each structural component of the optical film with a separator film lamination adhesive layer of the present invention.

[1] Optical film (A)
[1-1] Polarizing plate In the present specification, the polarizing plate means that a resin film or a resin layer is laminated on at least one surface of a polarizer. A polarizer is a film having the property of absorbing linearly polarized light having a vibration plane parallel to its absorption axis and transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis (parallel to the transmission axis). A film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film can be used. Examples of the dichroic dye include iodine and dichroic organic dyes.

  The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate which is a homopolymer of vinyl acetate, and a monomer copolymerizable with vinyl acetate (for example, unsaturated carboxylic acid, olefin, vinyl ether, unsaturated sulfonic acid, ammonium group). (Meth) acrylamide etc.) and vinyl acetate.

  The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1000 to 10000, preferably 1500 to 5000. The average degree of polymerization of the polyvinyl alcohol resin can be determined according to JIS K 6726.

  Usually, what formed the polyvinyl alcohol-type resin into a film can be used as a raw film of a polarizer. A polyvinyl alcohol-type resin can be formed into a film by a well-known method. The thickness of the raw film is usually 1 to 150 μm, and preferably 10 μm or more in consideration of easiness of stretching.

  The polarizer is, for example, a step of uniaxially stretching the original film, a step of dyeing the film with a dichroic dye to adsorb the dichroic dye, a step of treating the film with an aqueous boric acid solution, and A step of washing the film with water is performed, and finally the film is dried and manufactured. In the present invention, the thickness of the polarizer is usually 1 to 50 μm, and is preferably 30 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less from the viewpoint of thinning the optical film.

  A polarizer obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol resin film is as follows: 1) A single film of a polyvinyl alcohol resin film is used as a raw film, and this film is uniaxially stretched and a dichroic dye. 2) After applying a coating liquid (aqueous solution, etc.) containing a polyvinyl alcohol resin to the base film and drying to obtain a base film having a polyvinyl alcohol resin layer This can also be obtained by uniaxially stretching the whole base film, subjecting the stretched polyvinyl alcohol resin layer to a dichroic dyeing process, and then peeling and removing the base film. As a base film, the film which consists of a thermoplastic resin similar to the thermoplastic resin which can comprise the resin film mentioned later can be used. A film made of a polyester resin such as polyethylene terephthalate, a polycarbonate resin, a cellulose resin such as triacetyl cellulose, a cyclic polyolefin resin such as a norbornene resin, or a polystyrene resin is preferable. By using the method 2), it is easy to produce a thin film polarizer, for example, it is easy to produce a polarizer having a thickness of 7 μm or less.

  The resin film has a light transmitting property, preferably an optically transparent thermoplastic resin, such as a chain polyolefin resin (polyethylene resin, polypropylene resin, etc.), a cyclic polyolefin resin (norbornene resin, etc.), etc. Polyolefin resin; Cellulosic resin (cellulose ester resin, etc.); Polyester resin (polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc.); Polycarbonate resin (for example, 2,2-bis (4-hydroxyphenyl) propane (Meth) acrylic resin; polystyrene resin; polyetheretherketone resin; polysulfone resin, or a mixture or copolymer thereof, etc. It may be. Among them, the resin film is preferably a film composed of a cyclic polyolefin resin, a polycarbonate resin, a cellulose resin, a polyester resin, a (meth) acrylic resin, and the like, and in particular, a cellulose resin and a cyclic polyolefin resin. A film made of a resin or the like is preferable.

  Examples of the chain polyolefin resin include a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, and a copolymer composed of two or more chain olefins.

  Cyclic polyolefin resin is a general term for resins containing, as polymerized units, cyclic olefins such as norbornene, tetracyclododecene (also known as dimethanooctahydronaphthalene) or their derivatives. Cyclic polyolefin-based resins include cyclic olefin ring-opening (co) polymers and hydrogenated products thereof, cyclic olefin addition polymers, cyclic olefins and chain olefins such as ethylene and propylene, and aromatic compounds having a vinyl group And a modified (co) polymer obtained by modifying these with an unsaturated carboxylic acid or a derivative thereof. Among these, norbornene resins using norbornene monomers such as norbornene and polycyclic norbornene monomers as cyclic olefins are preferred.

  The cellulose-based resin is preferably a cellulose ester-based resin, that is, a cellulose partial or completely esterified product, and examples thereof include cellulose acetate ester, propionate ester, butyrate ester, and mixed ester thereof. Of these, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like are preferable.

  The polyester-based resin is a resin other than the cellulose ester-based resin having an ester bond, and is generally made of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, and polycyclohexanedimethyl naphthalate.

  The polycarbonate resin is a polyester formed from carbonic acid and glycol or bisphenol. Of these, aromatic polycarbonates having a diphenylalkane in the molecular chain are preferred from the viewpoints of heat resistance, weather resistance and acid resistance. Examples of the polycarbonate include 2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A), 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) cyclohexane, , 1-bis (4-hydroxyphenyl) isobutane, polycarbonate derived from bisphenols such as 1,1-bis (4-hydroxyphenyl) ethane, and the like.

The (meth) acrylic resin capable of constituting the resin film can be a polymer mainly composed of a structural unit derived from a methacrylic acid ester (for example, containing 50% by weight or more), and other copolymer components. It is preferable that is a copolymer in which is copolymerized. The (meth) acrylic resin may contain two or more types of structural units derived from methacrylic acid esters. Methacrylic acid esters, for example, C ₁ -C ₄ alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, butyl methacrylate.

Examples of the copolymer component that can be copolymerized with the methacrylic acid ester include acrylic acid esters. The acrylic acid ester is preferably a C ₁ -C ₈ alkyl ester of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and the like. Specific examples of other copolymer components include unsaturated acids such as (meth) acrylic acid; aromatic vinyl compounds such as styrene, halogenated styrene, α-methylstyrene, and vinyl toluene; vinylcyan such as (meth) acrylonitrile. Compound; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; unsaturated imides such as phenylmaleimide and cyclohexylmaleimide, etc. other than acrylic acid ester having one polymerizable carbon-carbon double bond in the molecule These compounds are mentioned. A compound having two or more polymerizable carbon-carbon double bonds in the molecule may be used as a copolymerization component. A copolymerization component can be used individually or in combination of 2 or more types.

  The (meth) acrylic resin may have a ring structure in the polymer main chain in that the durability of the film can be improved. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic imide structure, or a lactone ring structure. Specific examples of the cyclic acid anhydride structure include a glutaric anhydride structure and a succinic anhydride structure, and specific examples of the cyclic imide structure include a glutarimide structure and a succinimide structure. Examples include butyrolactone ring structure and valerolactone ring structure.

The (meth) acrylic resin may contain acrylic rubber particles from the viewpoints of film-formability on the film and impact resistance of the film. Acrylic rubber particles are particles having an elastic polymer mainly composed of an acrylate ester as an essential component. The acrylic rubber particles have a single-layer structure consisting essentially of this elastic polymer, or an elastic polymer in one layer. And a multilayer structure having Examples of the elastic polymer include a crosslinked elastic copolymer obtained by copolymerizing an alkyl acrylate as a main component with another vinyl monomer and a crosslinkable monomer copolymerizable therewith. The alkyl acrylate as a main component of the elastomeric polymer, for example, methyl acrylate, ethyl acrylate, butyl acrylate, C ₁ -C ₈ alkyl esters of acrylic acid such as 2-ethylhexyl acrylate and the like. The number of carbon atoms of the alkyl group is preferably 4 or more.

  Examples of other vinyl monomers copolymerizable with alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, and more specifically, methacrylic acid such as methyl methacrylate. Examples thereof include aromatic vinyl compounds such as esters and styrene, vinylcyan compounds such as (meth) acrylonitrile, and the like. Examples of the crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule, and more specifically, ethylene glycol di (meth) acrylate, butanediol di ( Examples include (meth) acrylates of polyhydric alcohols such as (meth) acrylate, alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate, and divinylbenzene.

  The content of the acrylic rubber particles is preferably 5 parts by mass or more, more preferably 10 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic resin. When the content of the acrylic rubber particles is excessively large, the surface hardness of the film is lowered, and when the film is subjected to a surface treatment, the solvent resistance against the organic solvent in the surface treatment agent can be lowered. Accordingly, the content of the acrylic rubber particles is usually 80 parts by mass or less, preferably 60 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic resin.

  The resin film can contain usual additives in the technical field of the present invention. Examples of the additive include an ultraviolet absorber, an infrared absorber, an organic dye, a pigment, an inorganic dye, an antioxidant, an antistatic agent, a surfactant, a lubricant, a dispersant, and a heat stabilizer. Examples of the ultraviolet absorber include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, triazine compounds, cyano (meth) acrylate compounds, nickel complex salts, and the like.

  The resin film may be an unstretched film or a uniaxial or biaxially stretched film. The resin film may be a protective film that plays a role of protecting the polarizer, or may be a protective film having an optical function such as a retardation film described later. In addition, when a polarizing plate contains two or more resin films, those resin films may be the same or different films.

  The resin film has a surface treatment layer such as a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, an antistatic layer, an antifouling layer and a conductive layer on the outer surface (the surface opposite to the polarizer). (Coating layer) may be provided. The thickness of the resin film is usually 1 to 50 μm, preferably 5 to 50 μm, and further 30 μm or less.

  The resin film can be bonded to the polarizer via an adhesive layer or a pressure-sensitive adhesive layer. As an adhesive forming the adhesive layer, a water-based adhesive or an active energy ray-curable adhesive can be used.

  As the water-based adhesive, a conventional water-based adhesive (for example, an adhesive comprising a polyvinyl alcohol resin aqueous solution, an aqueous two-component urethane emulsion adhesive, an aldehyde compound, an epoxy compound, a melamine compound, a methylol compound, an isocyanate compound, And crosslinking agents such as amine compounds and polyvalent metal salts). Among these, a water-based adhesive made of a polyvinyl alcohol-based resin aqueous solution can be suitably used. In addition, when using a water-based adhesive, after bonding a polarizer and a resin film, it is preferable to implement the process dried in order to remove the water contained in a water-based adhesive. After the drying process, for example, a curing process for curing at a temperature of about 20 to 45 ° C. may be provided.

  The active energy ray-curable adhesive refers to an adhesive that cures when irradiated with active energy rays such as ultraviolet rays and electron beams. For example, a curable composition containing a polymerizable compound and a photopolymerization initiator, light Examples thereof include a curable composition containing a reactive resin, a curable composition containing a binder resin and a photoreactive cross-linking agent, and preferably an ultraviolet curable adhesive.

  When using an active energy ray-curable adhesive, after bonding the polarizer and the resin film, if necessary, a drying step is performed, and then the active energy ray-curable adhesive is irradiated by irradiating active energy rays. A curing step for curing is performed. The light source of the active energy ray is not particularly limited, but ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable.

  Examples of the method of bonding the polarizer and the resin film include a method of subjecting at least one of these bonding surfaces to a surface activation treatment such as a saponification treatment, a corona treatment, and a plasma treatment. When a resin film is bonded to both surfaces of the polarizer, the adhesive for bonding these resin films may be the same type of adhesive or a different type of adhesive.

  Other films or layers may be further laminated on the polarizing plate. Specific examples thereof include a retardation film described later, a brightness enhancement film, an antiglare film, an antireflection film, a diffusion film, a condensing film, an adhesive layer other than the adhesive layer (B), a coating layer, a protective film, and the like. It is. A protective film is a film used for the purpose of protecting the surface of an optical film such as a polarizing plate from scratches and dirt, and is peeled off after an optical film with an adhesive layer is bonded onto, for example, a metal layer or a substrate. It is customary.

  The protective film is usually composed of a base film and an adhesive layer laminated thereon. The base film is composed of a thermoplastic resin, for example, a polyolefin resin such as polyethylene resin or polypropylene resin; a polyester resin such as polyethylene terephthalate or polyethylene naphthalate; a polycarbonate resin; a (meth) acrylic resin, or the like. be able to.

[1-2] Retardation plate In this specification, a retardation plate means that a resin film or a resin layer is laminated on at least one surface of a retardation film. The retardation film contained in the retardation plate is an optical film exhibiting optical anisotropy. In addition to the thermoplastic resin exemplified above as a resin film, for example, a polyvinyl alcohol resin, a polyarylate Resin film made of resin, polyimide resin, polyethersulfone resin, polyvinylidene fluoride / polymethyl methacrylate resin, liquid crystal polyester resin, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride resin, etc. It can be a stretched film obtained by stretching about 1.01 to 6 times. Among these, a polycarbonate film, a cyclic olefin resin film, a (meth) acrylic resin film or a cellulose resin film is preferably a uniaxially stretched or biaxially stretched film. In the present specification, a zero retardation film is also included in the retardation film (however, it can also be used as a protective film). In addition, a film called a uniaxial retardation film, a wide viewing angle retardation film, a low photoelastic modulus retardation film, or the like is also applicable as the retardation film.

The zero Letters retardation film in-plane retardation value _{R e} and the thickness direction retardation _{R th} means a film are both -15～15Nm. This retardation film is suitably used for an IPS mode liquid crystal display device. Plane retardation value _{R e} and the thickness direction retardation _{R th} are preferably both -10～10Nm, more preferably both -5～5Nm. The in-plane retardation value _Re and the thickness direction retardation value _Rth here are values at a wavelength of 590 nm.

The in-plane retardation value R _e and the thickness direction retardation value R _th are respectively represented by the following formulas:
_{R e = (n x -n y} ) × d
_Rth = [( _nx + _ny ) / 2- _nz ] * d
Defined by Wherein, n _x is a refractive index in a slow axis direction (x-axis direction) in the film plane, n _y is the fast axis direction in the film plane of the (y-axis direction orthogonal to the x-axis in a plane) It is a refractive index, _nz is the refractive index in the film thickness direction (z-axis direction perpendicular to the film surface), and d is the thickness of the film.

  As the zero retardation film, for example, a polyolefin resin such as a cellulose resin, a chain polyolefin resin and a cyclic polyolefin resin, a resin film made of a polyethylene terephthalate resin or a (meth) acrylic resin, or the like can be used. In particular, since the retardation value is easily controlled and easily available, a cellulose resin, a polyolefin resin, or a (meth) acrylic resin is preferably used.

  Moreover, the film which expressed optical anisotropy by application | coating and orientation of a liquid crystalline compound, and the film which expressed optical anisotropy by application | coating of an inorganic layered compound can also be used as retardation film. In such a retardation film, a so-called temperature compensation type retardation film, and a rod-like liquid crystal sold under the trade name “NH film” from JX Nippon Mining & Energy Co., Ltd. are tilted. Film, a film with a disc-shaped liquid crystal sold under the trade name “WV film” from FUJIFILM Corporation, and a complete biaxial film sold under the trade name “VAC film” from Sumitomo Chemical Co., Ltd. Examples of the orientation type film include a biaxial orientation type film sold by Sumitomo Chemical Co., Ltd. under the trade name “new VAC film”. In addition, the resin film laminated | stacked on the at least one surface of retardation film can be the above-mentioned protective film, for example.

  Generally, when the film thickness of the optical film (A) constituting the optical film with the separator film laminated pressure-sensitive adhesive layer is thin, the separator film and the pressure-sensitive adhesive layer thereunder are extremely small, specifically 1 mm in length. Wrinkles having a depth of about 0.1 μm to 1 μm are easily generated at a width of about 30 mm and a width of about 0.5 mm to 2 mm. Such streak-like wrinkles may move over time from the cut surface side toward the center when cut into chips. Such wrinkles are more likely to occur as the optical film (A) is thinner. For this reason, the suppression effect of the said wrinkle generation | occurrence | production can be exhibited more, so that the thickness of the optical film (A) which comprises an optical film with a separator film lamination adhesive layer is thin. Therefore, the thickness of the optical film (A) constituting the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention is usually 100 μm or less, preferably 80 μm or less, more preferably 70 μm or less. The lower limit of the film thickness of the optical film (A) is usually 5 μm or more, and is preferably 10 μm or more, for example, from the viewpoint of easy handling of the optical film (A), that is, handling, 15 μm or more. It is more preferable that

  Here, in the present invention, the “film thickness of the optical film (A)” means the thickness of a single layer when the optical film has a single layer structure, and the multilayer when the optical film has a multilayer structure. It means the sum of the thicknesses of all layers constituting the structure. When the optical film has a multilayer structure, a layer (for example, a protective film) finally peeled and removed when the optical film is incorporated into an optical laminate or a display device constitutes the optical film (A). It is not regarded as a layer to be used, and is not taken into consideration in the calculation of the film thickness of the optical film (A). Therefore, for example, in the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention shown in FIG. 1, the film thickness of the optical film (A) is the total of the polarizer 2, the first resin film 3, and the second resin film 4. It becomes thickness. Further, in the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention shown in FIG. 2, the optical film (A) has a film thickness of the polarizer 2, the first resin film 3, the second resin film 4, and the hard coat layer 6. The total thickness of

In the present invention, by balancing the film thickness of the separator film (C) and the film thickness of the optical film (A), the effect of suppressing the generation of such extremely small wrinkles can also be enhanced. it can. For example, the ratio of the optical film thickness T _{A to} the separator film thickness T _C (T _C / T _A ) is, for example, preferably 0.4 or more, more preferably 0.6 or more, and 0.7 More preferably, it is the above. The ratio _(T C / T _A) is usually 4 or less.

  In general, if the optical film (A) constituting the optical film with the separator film laminated pressure-sensitive adhesive layer has a high water absorption rate, a very small wrinkle-like wrinkle is likely to occur with the dimensional change of the optical film (A) accompanying water absorption. There is a tendency. Since such wrinkles can be suppressed, the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention is highly effective in suppressing such wrinkles. Even if the water absorption rate of the film (A) is, for example, 2.0% or more, further 3.0% or more, the generation of the wrinkles can be effectively suppressed. In addition, the water absorption rate of an optical film (A) can be measured according to the method described in an Example, for example, and is 10% or less normally.

  The water absorption rate of the optical film (A) varies depending on, for example, each film constituting the optical film (A). For example, when the optical film is a polarizing plate, depending on the material and thickness of the polarizer constituting the optical film, and the material and thickness of the resin film bonded to the polarizer, for example, when the polarizer is a polyvinyl alcohol resin The water absorption rate tends to increase as the thickness increases. For example, when a cellulose resin film is used as the resin film, the water absorption rate tends to increase as the thickness increases. Therefore, the water absorption rate of the optical film (A) can be controlled by the type and thickness of the materials constituting the various films.

[2] Adhesive layer (B)
As a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (B) (the pressure-sensitive adhesive layer 20 in FIGS. 1 and 2) laminated on at least one surface of the optical film (A) of the present invention, a conventionally known pressure-sensitive adhesive is particularly used. For example, an adhesive having a base polymer such as acrylic, rubber, urethane, silicone, or polyvinyl ether can be used. Further, an energy ray curable pressure sensitive adhesive, a thermosetting pressure sensitive adhesive, or the like may be used. Among these, an adhesive having a base polymer of an acrylic resin that is excellent in transparency, adhesive strength, reworkability, weather resistance, heat resistance, and the like is preferable. In a preferred embodiment of the present invention, the pressure-sensitive adhesive layer (B) is obtained from a reaction product of a pressure-sensitive adhesive composition containing a (meth) acrylic resin (a), a crosslinking agent (b), and a silane compound (c). Composed.

[2-1] (Meth) acrylic resin (a)
In the present invention, the (meth) acrylic resin (a) that can be contained in the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer (B) is derived from a (meth) acrylic acid alkyl ester represented by the following formula (I). A polymer having a structural unit (hereinafter also referred to as “structural unit (I)”) as a main component (for example, containing 50% by weight or more) (hereinafter also referred to as “(meth) acrylic acid ester polymer”). Preferably

(In the formula, R ¹⁰ represents a hydrogen atom or a methyl group, R ²⁰ represents an alkyl group having 1 to 20 carbon atoms, and the alkyl group has a linear, branched, or cyclic structure. The hydrogen atom of the alkyl group may be replaced with an alkoxy group having 1 to 10 carbon atoms.)
In the present specification, “(meth) acrylic acid” means either acrylic acid or methacrylic acid, and “(meth)” such as (meth) acrylate has the same meaning.

As the (meth) acrylic acid ester represented by the formula (I), for example,
Methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, i-hexyl acrylate, n-heptyl acrylate, n- Octyl acrylate, i-octyl acrylate, 2-ethylhexyl acrylate, n- and i-nonyl acrylate, n-decyl acrylate, i-decyl acrylate, n-dodecyl acrylate, cyclohexyl acrylate, isobornyl acrylate, stearyl acrylate, t -Butyl acrylate etc. are mentioned. Specific examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl acrylate and ethoxymethyl acrylate.

  The (meth) acrylic acid ester polymer may contain two or more kinds of structural units (I). In addition, from the viewpoint of achieving both cohesion and durability, the copolymer may include a structural unit having a glass transition temperature Tg of a homopolymer of 0 ° C. or more and a structural unit having a Tg of the homopolymer of less than 0 ° C. preferable. Examples of the structural unit having a glass transition temperature (Tg) of the homopolymer of 0 ° C. or higher include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate and the like, and include methyl acrylate or isobornyl acrylate from the viewpoint of durability. Is more preferable. The structural unit whose Tg of the homopolymer is less than 0 ° C. includes ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, i -Hexyl acrylate, n-heptyl acrylate, n-octyl acrylate i-octyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, i-nonyl acrylate, n-decyl acrylate, i-decyl acrylate, n-dodecyl acrylate Among them, n-butyl acrylate or 2-ethylhexyl acrylate is preferably included, and n-butyl acrylate is particularly preferable.

  The (meth) acrylic acid ester polymer may contain a structural unit derived from a monomer other than the structural unit (I). One type of structural unit derived from another monomer may be used, or two or more types may be used. Specific examples of other monomers that the (meth) acrylic acid ester polymer may contain are shown below.

1) Monomer having a polar functional group The (meth) acrylic acid ester polymer may contain a structural unit derived from a monomer having a polar functional group. Examples of the monomer having a polar functional group include (meth) acrylates having a polar functional group. Examples of the polar functional group include a hydroxy group, a carboxyl group, a substituted amino group, and an unsubstituted amino group. Examples of polar functional groups include heterocyclic groups such as epoxy groups. Specific examples of the (meth) acrylate having such a polar functional group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth ) Hydroxy such as 2- (2-hydroxyethoxy) ethyl acrylate, 2-chloro-2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, etc. Monomers having a group: acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth) acryl Monomer having a heterocyclic group such as glycidyl (meth) acrylate, 2,5-dihydrofuran; aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) ) Monomers having a substituted or unsubstituted amino group such as acrylate; monomers having a carboxyl group such as (meth) acrylic acid and carboxyethyl (meth) acrylate. Especially, the monomer which has a hydroxyl group is preferable, and the (meth) acrylate which has a hydroxyl group is more preferable at the reactive point of (meth) acrylic-type resin (a) and a crosslinking agent.

  The (meth) acrylic acid ester polymer may contain a monomer having the other polar functional group in combination with the (meth) acrylate having a hydroxy group, but is laminated on the outer surface of the pressure-sensitive adhesive layer. It is preferable that the monomer which has an amino group is substantially not included from a viewpoint of preventing the peeling force increase of the separator film which can be manufactured. Here, “substantially free” means that it is 1.0 part by mass or less in 100 parts by mass of all the structural units constituting the (meth) acrylic resin (a). Moreover, it is preferable that the monomer which has a carboxyl group is not included substantially from a viewpoint of improving the corrosion resistance with respect to transparent electrodes, such as ITO. Here, “substantially free” means that it is 2.0 parts by mass or less in 100 parts by mass of all the structural units constituting the (meth) acrylic resin (a).

  The content of the structural unit derived from the monomer having a polar functional group in the (meth) acrylic acid ester polymer is preferably 20 with respect to 100 parts by mass of all structural units of the (meth) acrylic acid ester polymer. It is not more than 0.1 parts by mass, more preferably not less than 0.1 parts by mass and not more than 20 parts by mass, still more preferably not less than 0.1 parts by mass and not more than 10 parts by mass, and particularly preferably not less than 0.5 parts by mass and not more than 10 parts by mass.

2) A monomer having an aromatic group The (meth) acrylic acid ester polymer may contain a structural unit derived from a monomer having an aromatic group. The monomer having an aromatic group has one (meth) acryloyl group and one or more aromatic rings (for example, a benzene ring, a naphthalene ring, etc.) in the molecule, a phenyl group, a phenoxyethyl group, Or the (meth) acrylic acid ester which has a benzyl group is mentioned. By including these structural units, the white spot phenomenon of the polarizing plate during the durability test can be suppressed.

  Examples of the (meth) acrylic acid ester having a phenoxyethyl group include 2-methoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, and ethylene oxide modification of (meth) acrylic acid. Nonylphenol ester, 2- (o-phenylphenoxy) ethyl (meth) acrylate, and the like can be mentioned. Examples of the structural unit having a benzyl group include benzyl acrylate. Of these, 2-methoxyethyl (meth) acrylate and 2- (2-phenoxyethoxy) ethyl (meth) acrylate are preferable from the viewpoint of suppressing white spots.

  The content of the structural unit derived from the monomer having an aromatic group in the (meth) acrylic acid ester polymer is preferably 50 with respect to 100 parts by mass of the total structural unit of the (meth) acrylic acid ester polymer. It is 4 parts by mass or more, more preferably 4 parts by mass or more and 50 parts by mass or less, and further preferably 4 parts by mass or more and 25 parts by mass or less.

3) The acrylamide monomer (meth) acrylate polymer may contain a structural unit derived from a monomer having an acrylamide group. Examples of the monomer having an acrylamide group include N-methylolacrylamide, N- (2-hydroxyethyl) acrylamide, N- (3-hydroxypropyl) acrylamide, N- (4-hydroxybutyl) acrylamide, and N- ( 5-hydroxypentyl) acrylamide, N- (6-hydroxyhexyl) acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-isopropylacrylamide, N- (3-dimethylaminopropyl) acrylamide, N- ( 1,1-dimethyl-3-oxobutyl) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl] acrylamide, 2-acryloylamino-2-methyl-1-propanesulfonic acid, N- (methoxymethyl) Acry Amide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (1-methylethoxymethyl) acrylamide, N- (1-methylpropoxymethyl) acrylamide, N- (2-methylpropoxymethyl) acrylamide [Alias: N- (isobutoxymethyl) acrylamide], N- (butoxymethyl) acrylamide, N- (1,1-dimethylethoxymethyl) acrylamide, N- (2-methoxyethyl) acrylamide, N- (2-ethoxy Ethyl) acrylamide, N- (2-propoxyethyl) acrylamide, N- [2- (1-methylethoxy) ethyl] acrylamide, N- [2- (1-methylpropoxy) ethyl] acrylamide, N- [2- ( 2-methylpropoxy) ethyl] Ruamido [alias: N- (2-isobutoxy-ethyl) acrylamide], N- (2-butoxyethyl) acrylamide, such as N- [2- (1,1-dimethylethoxy) ethyl] acrylamide. By including these structural units, bleeding out of additives such as an antistatic agent can be suppressed. Among these, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, N- (2-methylpropoxymethyl) acrylamide and the like are preferable.

  Furthermore, as the structural unit derived from other monomers other than the structural unit (I), a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer, and a plurality of ( Examples also include structural units derived from monomers having a (meth) acryloyl group.

  Examples of the styrenic monomer include styrene; alkyl styrene such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, octyl styrene; fluoro Halogenated styrene such as styrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene.

  Examples of vinyl monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate and vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride And vinylidene halides such as vinyl pyridine, vinyl pyrrolidone and vinyl carbazole; conjugated dienes such as butadiene, isoprene and chloroprene; and unsaturated nitriles such as acrylonitrile and methacrylonitrile.

  Examples of the monomer having a plurality of (meth) acryloyl groups in the molecule include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol. 2 (meth) acryloyl in the molecule such as di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate Monomer having a group; a monomer having three (meth) acryloyl groups in the molecule such as trimethylolpropane tri (meth) acrylate.

  The weight average molecular weight (Mw) of the (meth) acrylic resin (a) is preferably 500,000 to 2,500,000. When the weight average molecular weight is 500,000 or more, the durability of the pressure-sensitive adhesive layer in a high-humidity heat environment can be improved. When the weight average molecular weight is 2.5 million or less, the handling property when the pressure-sensitive adhesive solution is applied becomes good. The molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is usually 2-10. The weight average molecular weight can be analyzed by gel permeation chromatography and is a value in terms of standard polystyrene.

  When the (meth) acrylic resin (a) is dissolved in ethyl acetate to give a solution having a concentration of 20% by weight, the viscosity at 25 ° C. is preferably 20 Pa · s or less, preferably 0.1 to 15 Pa · s. It is more preferable that The viscosity in such a range is advantageous for improving the durability of the optical film with the pressure-sensitive adhesive layer and the optical laminate including the same, and for reworkability of the optical film with the pressure-sensitive adhesive layer. The viscosity can be measured with a Brookfield viscometer.

  From the viewpoint of achieving both tackiness and durability, the glass transition temperature of the (meth) acrylic resin (a) is preferably −10 ° C. to −60 ° C. The glass transition temperature can be measured with a differential scanning calorimeter (DSC).

  The (meth) acrylic resin (a) can be usually produced by a known polymerization method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, or an emulsion polymerization method. In the production of the (meth) acrylic resin (a), polymerization is usually performed in the presence of a polymerization initiator. The usage-amount of a polymerization initiator is 0.001-5 mass parts normally with respect to a total of 100 mass parts of all the monomers which comprise (meth) acrylic-type resin (a). The (meth) acrylic resin (a) can also be produced by a method of polymerizing with active energy rays such as ultraviolet rays.

  Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone. As thermal polymerization initiators, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2 , 2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) Azo compounds such as 2,2′-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxide Oxydicarbonate, dipropylperoxydicarbonate, tert-butyl Organic peroxides such as oxyneodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, hydrogen peroxide Is mentioned. Moreover, the redox initiator which used the peroxide and the reducing agent together can also be used as a polymerization initiator.

  The (meth) acrylic resin (a) is preferably produced by a solution polymerization method. Specifically, a desired monomer and an organic solvent are mixed, and a thermal polymerization initiator is added to the obtained solution under a nitrogen atmosphere. A (meth) acrylic acid ester polymer can be obtained by stirring the resulting mixture at about 40 ° C. to 90 ° C., preferably about 60 ° C. to 80 ° C. for about 3 to 10 hours. In order to control the polymerization reaction, a monomer, a thermal polymerization initiator or both are added to the reaction system continuously or intermittently during the polymerization reaction, or in a state dissolved in an organic solvent. Also good. Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; aliphatic alcohol solvents such as propyl alcohol and isopropyl alcohol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Can be mentioned.

  The (meth) acrylic resin (a) may contain two or more (meth) acrylic acid ester polymers. As such (meth) acrylic acid ester polymer, for example, the main component is the structural unit (I) derived from the (meth) acrylic acid ester, and the weight average molecular weight is 50,000 to 300,000. (Meth) acrylic acid ester polymer having a relatively low molecular weight as in the range of

[2-2] Crosslinking agent (b)
It is preferable that the adhesive composition which forms an adhesive layer (B) contains a crosslinking agent (b). Examples of the crosslinking agent (b) include conventional crosslinking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.), particularly with the pot life of the pressure-sensitive adhesive composition and the pressure-sensitive adhesive layer. From the viewpoint of the durability of the optical film, the crosslinking rate, etc., an isocyanate compound is preferable.

  As the isocyanate compound, a compound having at least two isocyanato groups (—NCO) in the molecule is preferable. For example, an aliphatic isocyanate compound (for example, hexamethylene diisocyanate), an alicyclic isocyanate compound (for example, isophorone diisocyanate). ), Aromatic isocyanate compounds (for example, tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). The crosslinking agent (b) is an adduct (adduct) of the isocyanate compound with a polyhydric alcohol compound [for example, an adduct with glycerol, trimethylolpropane or the like], an isocyanurate, a burette type compound, a polyether polyol, or a polyester. It may be a derivative such as a urethane prepolymer type isocyanate compound obtained by addition reaction with a polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol or the like. A crosslinking agent (b) can be used individually or in combination of 2 or more types. Of these, tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate and their polyhydric alcohol compounds or their isocyanurates are preferred from the viewpoint of durability.

  The ratio of the crosslinking agent (b) is, for example, 0.01 to 10 parts by mass (for example, 0.05 to 5 parts by mass), preferably 0.1 with respect to 100 parts by mass of the (meth) acrylic resin (a). -3 mass parts (for example, 0.1-2 mass parts), More preferably, 0.1-1 mass parts (for example, 0.1-0.8 mass parts) may be sufficient. When it is at most the upper limit value, it is advantageous for improving durability (peeling resistance), and when it is at least the lower limit value, it is advantageous for improving foam resistance and reworkability.

[2-3] Silane compound (c)
The pressure-sensitive adhesive composition contains a silane compound (c). Thereby, the adhesiveness of an adhesive layer and a glass substrate etc. can be improved. Two or more silane compounds (c) may be used.

  Examples of the silane compound (c) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3 -Glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, Examples include 3-methacryloyloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

  The silane compound (c) can include a silicone oligomer type. A specific example of the silicone oligomer is expressed in the form of a combination of monomers as follows.

  3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane Mercaptopropyl group-containing oligomers such as oligomers; mercaptomethyltrimethoxysilane-tetramethoxysilane oligomers, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomers, mercaptomethyltriethoxysilane-tetramethoxysilane oligomers, mercaptomethyltriethoxysilane-tetraethoxy Mercaptomethyl group-containing oligomers such as silane oligomers; 3-glycidoxypropyl Limethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetra Ethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyl group-containing copolymers such as 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; Cypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxy Silane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxy Propylmethyldiethoxysilane-tetraethoxysilane oligomer, etc. Methacryloyloxypropyl group-containing oligomers of: 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxy Silane-tetramethoxysilane oligomer, 3-acryloyloxypropylme Acrylyloxypropyl group-containing oligomer such as rudiethoxysilane-tetraethoxysilane oligomer; vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxy Silane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, vinylmethyldiethoxysilane-tetraethoxysilane oligomer, etc. Vinyl group-containing oligomer; 3-aminopropyltrimethoxysilane-tetramethoxysilane Limer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetra Amino group-containing compounds such as methoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer, etc. Copolymer etc.

  Content of the silane compound (c) in an adhesive composition is 0.01-10 mass parts normally with respect to 100 mass parts of (meth) acrylic-type resin (a), Preferably it is 0.03-5 mass. Part, more preferably 0.05 to 2 parts by mass, still more preferably 0.1 to 1 part by mass. When the content of the silane compound (c) is 0.01 parts by mass or more, an effect of improving the adhesion between the pressure-sensitive adhesive layer and the substrate (glass or transparent electrode) is easily obtained. Moreover, the bleeding out of the silane compound (c) from an adhesive layer can be suppressed as content is 10 mass parts or less.

[2-4] Antistatic agent The adhesive composition which forms an adhesive layer (B) may further contain an antistatic agent. By including an antistatic agent, the antistatic property of the optical film with the separator film laminated adhesive layer can be improved. For example, when the separator film is peeled off, a protective film or the like is further bonded to the optical film side. In the case of being peeled off, it is possible to suppress problems caused by static electricity that occur when peeling it off.

Examples of the antistatic agent include conventional ones, and ionic antistatic agents are preferred. Examples of the cation component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of the organic cation include a pyridinium cation, an imidazolium cation, an ammonium cation, a pyrrolidinium cation, a piperidinium cation, a sulfonium cation, and a phosphonium cation. Examples of the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. The anionic component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, but an anionic component containing a fluorine atom is preferred from the viewpoint of excellent antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion (PF _6- ), bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N-], bis (fluorosulfonyl) imide anion [(FSO ₂ ) ₂ N-], tetra (pentafluorophenyl) borate anion [(C ₆ F ₅ ) ₄ B-] and the like. These antistatic agents can be used alone or in combination of two or more.

  An ionic antistatic agent that is solid at room temperature is particularly preferred in that the antistatic performance of the pressure-sensitive adhesive composition is excellent over time. The ratio of the antistatic agent is, for example, 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, and more preferably 0.5 to 100 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin (a). It may be 4 weights.

[2-5] Other components The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer (B) is composed of a solvent, a crosslinking catalyst, an ultraviolet absorber, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, and an inorganic material. Additives such as fillers, light-scattering fine particles, and rust inhibitors can be used alone or in combination of two or more. It is also useful to blend an ultraviolet curable compound into the pressure-sensitive adhesive composition and form a pressure-sensitive adhesive layer and then cure it by irradiating with ultraviolet rays to form a harder pressure-sensitive adhesive layer.

  The thickness of the pressure-sensitive adhesive layer is usually 2 to 40 μm. The durability of the optical film with a separator film laminated pressure-sensitive adhesive layer and the separator film are peeled off, and the optical film is attached to a liquid crystal cell or the like with the exposed pressure-sensitive adhesive layer. Later, when the optical film is peeled off from the liquid crystal cell for any reason, the optical film with the pressure-sensitive adhesive layer can be peeled off with a light force during an operation called so-called rework, and the pressure-sensitive adhesive remains on the liquid crystal cell side. It is preferably 5 to 30 μm, more preferably 10 to 25 μm, in that a phenomenon called so-called adhesive residue hardly occurs and reworking is easy. The durability of the optical film with the pressure-sensitive adhesive layer is good when it is not more than the above upper limit value, and the reworkability is good when it is not less than the lower limit value.

  [3] Separator film (C)

  The separator film (C) constituting the optical film with the separator film laminated pressure-sensitive adhesive layer of the present invention preferably has a bending stiffness of 1 mg or more. When the bending stiffness is 1 mg or more, generation of extremely small streak-like wrinkles can be more effectively suppressed. In the present invention, the bending stiffness of the separator film (C) is more preferably 1.5 mg or more. The upper limit of the bending stiffness of the separator film (C) is usually 100 mg or less, preferably 50 mg or less, and more preferably 50 mg or less because the separator film can be easily raised when the separator film is peeled from the adhesive layer. Is 30 mg or less. The bending stiffness is a value measured according to the method described in the examples.

  The bending stiffness of the separator film (C) can be controlled within a desired range depending on, for example, the thickness of the plastic film constituting the separator film, film forming conditions (particularly stretching conditions), and the like. Specifically, for example, the bending stiffness can be increased by increasing the thickness of the base material or increasing the tensile elastic modulus of the base material.

  In the present invention, the separator film (C) is preferably composed of a plastic film and a release layer. As a plastic film, polyolefin films, such as polyester films, such as a polyethylene terephthalate film, a polybutylene terephthalate film, and a polyethylene naphthalate film, and a polypropylene film, are mentioned, for example. Among them, a polyethylene terephthalate film is preferable from the viewpoint of optical characteristics and quality, and a biaxially stretched polyethylene terephthalate film is preferable because of excellent dimensional stability. Further, the release layer can be formed from, for example, a release layer forming composition, and the main component (resin) constituting the release layer forming composition is not particularly limited, and examples thereof include silicone resins and alkyd resins. , Acrylic resins, and long-chain alkyl resins. Of these, silicone resins are preferred.

  Examples of the silicone resin include silicone resins having dimethylpolysiloxane as a basic skeleton. Examples of the silicone resin include addition reaction type, condensation reaction type, ultraviolet curable type, and electron beam curable type. Among these, addition-reactive silicone resins are preferably used because they have high reactivity and excellent productivity, and have advantages such as less change in peel strength after production and no cure shrinkage compared to the condensation reaction type.

  Specific examples of the addition reaction type silicone resin include organos having two or more alkenyl groups having 2 to 10 carbon atoms such as vinyl group, allyl group, propenyl group and hexenyl group at the terminal and / or side chain of the molecule. Polysiloxane etc. are mentioned. When such an addition reaction type silicone resin is used, it is preferable to use a crosslinking agent and a catalyst in combination.

  Examples of the crosslinking agent include, for example, organopolysiloxane having hydrogen atoms bonded to at least two silicon atoms in one molecule, specifically, a dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer. , Trimethylsiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped methylhydrogenpolysiloxane, poly (hydrogensilsesquioxane), and the like.

  Examples of the catalyst include fine platinum particles, fine platinum particles adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, white metal compounds such as palladium and rhodium, and the like. Can be mentioned. By using such a catalyst, the curing reaction of the composition for forming a release layer can be advanced more efficiently.

When a silicone resin is used for the release layer forming composition, it is preferable to add a release adjusting agent such as MQ resin.
Moreover, you may mix | blend an additive suitably with the composition for peeling layer formation. Examples of the additive include a catalyst, a dye, and a dispersant. Further, the composition for forming a release layer may appropriately contain a dispersion medium or a solvent in order to bring the viscosity at the time of coating into an appropriate range.
Examples of the dispersion medium or solvent include aromatic solvents such as toluene, fatty acid esters such as ethyl acetate, ketones such as methyl ethyl ketone, and organic solvents such as aliphatic hydrocarbons such as hexane and heptane.

The separator film (C) can be produced, for example, by applying a release layer-forming composition diluted in a solvent to one surface of a plastic film by the following method. Examples include gravure coating, bar coating, spray coating, spin coating, air knife coating, roll coating, blade coating, gate roll coating, and die coating. Among these, the gravure coating method and the bar coating method are preferable, and the gravure coating method is more preferable.
Moreover, as a heating / drying method of the composition for forming a release layer, for example, a method of heat drying in a hot air drying furnace or the like can be mentioned. The drying temperature is, for example, 50 ° C. or higher and 150 ° C. or lower. Moreover, it is preferable that drying time is 10 second-5 minutes, for example.

  The film thickness of the separator film (C) can be controlled by the thickness of the plastic film and the thickness of the release layer. Above all, the thickness of the plastic film is dominant and can be controlled by selecting a polyester film having a target thickness. The thickness of the plastic film is preferably 45 μm or more, more preferably 47 μm or more, and further preferably 50 μm or more. The upper limit of the film thickness of the plastic film is not particularly limited, but is usually 200 μm or less, and is preferably 150 μm or less, for example, because it is easy to cause the separator film to peel off, More preferably, it is 100 μm or less. The thickness (when dried) of the release layer is preferably 40 to 300 nm, more preferably 50 to 200 nm, and further preferably 80 to 150 nm. By setting the thickness of the release layer to 40 nm or more, it is possible to suppress variations in the peel force due to fluctuations in the coating amount, and by setting the thickness to 300 nm or less, blocking can be suppressed.

  In this invention, the peeling force with respect to a separator film (C) and an adhesive layer (B) may be 0.01-0.10N / 25mm, for example, and it is preferable that it is 0.02-0.08N / 25mm. When the peeling force of the separator film (C) is within the above range, the interfacial creep force with the pressure-sensitive adhesive layer (B) increases, and the generation and progression of streak-like wrinkles such as when the optical film is cut into chips The suppression effect can be enhanced. The peeling force of the separator film can be controlled by, for example, the polarity and elastic modulus of the release layer surface. Specifically, for example, as a heavy release adjusting agent, silicone resin or silica can be added to the release layer forming composition. It can be controlled by adding silicone oil or the like as a light release modifier to the release layer forming composition. In addition, the said peeling force was based on JIS-Z0237, the optical film with a separator film lamination adhesive layer was cut | judged to width 25mm and length 200mm, and the optical film with an adhesive layer was fixed using the tensile tester. In this state, it can be measured by pulling the separator film in the 180 ° direction at a speed of 300 mm / min.

  Moreover, the elasticity modulus of the peeling layer of a separator film (C) may be 0.3-15.0 MPa, for example, and it is preferable that it is 0.5-7.0 MPa. When the elastic modulus of the release layer of the separator film (C) is in the above range, the creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is increased, and the optical film is cut into chips. The effect of suppressing the generation and progression of streak-like wrinkles can be enhanced. The elastic modulus of the release layer can be controlled, for example, by increasing the amount of vinyl groups used in the silicone resin or by adding an additive such as silicone resin or silica to the release layer forming composition. In addition, the said elasticity modulus can be measured by DMA (23 degreeC) using the silicone block produced by casting the composition for peeling layer formation.

[4] Configuration and production method of optical film with separator film laminated pressure-sensitive adhesive layer For example, as shown in FIG. 1, the optical film 1 with separator film laminated pressure-sensitive adhesive layer is laminated on at least one surface of the optical film 10. The separator film 30 is laminated on the outer surface of the pressure-sensitive adhesive layer 20. An adhesive layer 20 is laminated on one side of the optical film 10. When laminating the pressure-sensitive adhesive layer 20 on the surface of the optical film 10, a primer layer is formed on the bonding surface of the optical film 10 and / or the bonding surface of the pressure-sensitive adhesive layer 20, or surface activation treatment (for example, (Plasma treatment, corona treatment, etc.) are preferable, and corona treatment is particularly preferable.

  A separate antistatic layer may be provided between the optical film 10 and the pressure-sensitive adhesive layer 20. As the antistatic layer, silicon materials such as polysiloxane, inorganic metal materials such as tin-doped indium oxide and tin-doped antimony oxide, and organic polymer materials such as polythiophene, polystyrene sulfonic acid, and polyaniline can be used.

  In the separator film laminated pressure-sensitive adhesive layer-attached optical film 1, for example, each component constituting the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer (B) is dissolved or dispersed in a solvent to obtain a solvent-containing pressure-sensitive adhesive composition. It can be obtained by applying and drying this to the release treatment surface of the separator film 30 to form the pressure-sensitive adhesive layer 20 and laminating (transferring) the pressure-sensitive adhesive layer 20 on the surface of the optical film 10.

  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. Hereinafter, the parts and% representing the amount used and the content are based on mass unless otherwise specified.

1. Separator film (1) Preparation of separator film (i-1) Preparation of release layer forming composition (a)
Organopolysiloxane with vinyl group and organopolysiloxane with hydrosilyl group, and silicone resin solution containing heavy release additive (trade name: BY24-571, solid content 30% by mass, manufactured by Toray Dow Corning) Was diluted with a solvent of 30 parts by mass in terms of solid content and toluene / MEK = 1/1 so that the solid content concentration was 1.0% by mass. 2 parts by mass of a platinum catalyst (trade name: SRX-212, solid content: 100% by mass) manufactured by Toray Dow Corning Co., Ltd. was added to this solution to prepare a release layer forming composition (a).

(I-2) Preparation of composition for forming release layer (b)
Organopolysiloxane with vinyl group and organopolysiloxane with hydrosilyl group, and silicone resin solution containing heavy release additive (trade name: BY24-561, solid content 30% by mass, manufactured by Toray Dow Corning) Was diluted with a solvent of 30 parts by mass in terms of solid content and toluene / MEK = 1/1 so that the solid content concentration was 1.0% by mass. 2 parts by mass of a platinum-based catalyst (trade name: SRX-212, solid content: 100% by mass) manufactured by Toray Dow Corning Co., Ltd. was added to this solution to prepare a release layer forming composition (b).

(Ii) Production of Separator 1 A biaxially stretched polyethylene terephthalate (PET) film A (Mitsubishi Resin PET50T-193) having a thickness of 50 μm, an end orientation angle of 8 degrees, and a haze of 3% was prepared. Next, on one surface of the biaxially stretched PET film A, the release layer forming composition (a) obtained above was applied with a bar coater so that the thickness after drying was 0.1 μm. A release layer was formed by drying at 120 ° C. for 1 minute to obtain a separator film 1 (separator 1). The bending stiffness of the separator 1 measured according to the method described later was 1.73 mg.

(Iii) Production of Separator 2 A biaxially stretched polyethylene terephthalate (PET) film B (PET38R-64 manufactured by Toray) having a thickness of 38 μm, an end orientation angle of 6 degrees, and a haze of 10% was prepared. Next, on one surface of the biaxially stretched PET film A, the release layer forming composition (a) obtained above was applied with a bar coater so that the thickness after drying was 0.1 μm. A release layer was formed by drying at 120 ° C. for 1 minute to obtain a separator film 2 (separator 2). The bending stiffness of the separator 2 measured according to the method described later was 0.53 mg.

(Iv) Production of Separator 3 A biaxially stretched polyethylene terephthalate (PET) film A (Mitsubishi Resin PET50T-193) having a thickness of 50 μm, an end orientation angle of 8 degrees, and a haze of 3% was prepared. Next, on one surface of the biaxially stretched PET film A, the release layer forming composition (b) obtained above was applied with a bar coater so that the thickness after drying was 0.1 μm. A release layer was formed by drying at 120 ° C. for 1 minute to obtain a separator film 3 (separator 3). The bending stiffness of the separator 3 is equivalent to that of the separator 1 (about 1.73 mg).

(V) Preparation of Separator 4 A biaxially stretched polyethylene terephthalate (PET) film B (PET38R-64 manufactured by Toray) having a thickness of 38 μm, an end orientation angle of 6 degrees, and a haze of 10% was prepared. Next, on one surface of the biaxially stretched PET film A, the release layer forming composition (b) obtained above was applied with a bar coater so that the thickness after drying was 0.1 μm. A release layer was formed by drying at 120 ° C. for 1 minute to obtain a separator film 4 (separator 4). The bending stiffness of the separator 4 is equivalent to that of the separator 2 (about 0.53 mg).

(2) Physical property measurement of separator film (i) Bending stiffness <Preparation for measurement>
After the separators 1 to 4 prepared above were cut into test pieces each having a size of 25.4 mm × 25.4 mm, one end of the test piece was connected to a Gurley type tester (Gurley Tefness Tester (electric type) 2094-M: (Made by Kumagai Riki Kogyo Co., Ltd.) The chuck is fixed at a position of 1 inch (25.4 mm) on the movable arm A, and the test piece is moved away from the apex of the pendulum B. Next, a 5 g weight was attached to the position of the lower load attachment hole a (1 inch) from the fulcrum of the pendulum B to make it vertical without vibration.

<Measurement operation>
The movable arm was moved at a constant speed to the right or left at a speed of 2 times / minute. The scale R when the lower part of the test piece was in contact with the pendulum B and moved away from the pendulum B was read and applied to the following conversion formula to calculate the bending stiffness.
S = ((aWa + bWb + cWc) / 5) × (l ² /b)×11.1×R (mg)
S: Stiffness of bending (mg)
a, b, c: Distance between load mounting hole and pendulum fulcrum (inch)
Wa, Wb, Wc: Weight of weight attached to load attachment hole (g)
l: Total length of test specimen -1/2 "(inch)
b: Specimen width (inch)
R: Scale reading

2. Preparation of optical film and optical film with separator film laminated pressure-sensitive adhesive layer (1) Preparation of (meth) acrylic resin for pressure-sensitive adhesive layer In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device and nitrogen introduction tube, N-butyl acrylate 87.5 parts by weight, methyl acrylate 5 parts by weight, 2-phenylethyl acrylate 5 parts by weight, 2-hydroxyethyl acrylate 2.5 parts by weight, ethyl acetate 200 parts by weight, and 2,2 0.08 part by mass of '-azobisisobutyronitrile was charged, and the air in the reaction vessel was replaced with nitrogen gas. While stirring in this nitrogen atmosphere, the reaction solution was heated to 60 ° C., reacted for 16 hours, and then cooled to room temperature. Here, a molecular weight of a part of the obtained solution was measured by a method described later, and production of a (meth) acrylic acid ester polymer having a weight average molecular weight of 2 million was confirmed.

The weight average molecular weight (Mw) of the (meth) acrylic resin is a polystyrene equivalent weight average molecular weight measured under the following conditions using gel permeation chromatography (GPC).
〔Measurement condition〕
GPC measurement device: manufactured by Tosoh Corporation, HLC-8020
GPC column (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (× 2)
TSK gel G2000HXL
・ Measurement solvent: Tetrahydrofuran ・ Measurement temperature: 40 ° C.

(2) Preparation of pressure-sensitive adhesive layer (a) Preparation of pressure-sensitive adhesive composition (a) Preparation of pressure-sensitive adhesive composition 100 parts by mass of the (meth) acrylic acid ester polymer obtained in the above step (1) (in terms of solid content) Value; the same applies hereinafter) and 0.20 parts by mass of trimethylolpropane-modified xylylene diisocyanate (trade name “Takenate D110N” manufactured by Mitsui Takeda Chemical Co., Ltd.) as the isocyanate-based crosslinking agent (B), and a silane coupling agent (C ), 0.30 parts by mass of a co-condensate of 3-mercaptopropyltrimethoxysilane and methyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X41-1810”), sufficiently stirred, By diluting with ethyl acetate, a coating solution of the adhesive composition was obtained.

(B1) Production of pressure-sensitive adhesive layer 1 (pressure-sensitive adhesive sheet 1) The above-described (a) is such that the release-treated surface (peeling layer surface) of the separator 1 obtained above is 20 μm after drying by an applicator. After the pressure-sensitive adhesive composition prepared in Step 1 was applied, the pressure-sensitive adhesive layer 1 was obtained as the pressure-sensitive adhesive sheet 1 by drying at 100 ° C. for 1 minute.

(B2) Preparation of pressure-sensitive adhesive layer 2 (pressure-sensitive adhesive sheet 2) The pressure-sensitive adhesive sheet 2 was operated in the same manner as the pressure-sensitive adhesive layer 1 except that the separator 2 obtained above was used instead of the separator 1. Layer 2 was obtained.

(B3) Preparation of pressure-sensitive adhesive layer 3 (pressure-sensitive adhesive sheet 3) The pressure-sensitive adhesive sheet 3 was operated in the same manner as the pressure-sensitive adhesive layer 1 except that the separator 3 obtained above was used instead of the separator 1. Layer 3 was obtained.

(B4) Preparation of pressure-sensitive adhesive layer 4 (pressure-sensitive adhesive sheet 4) The pressure-sensitive adhesive sheet 4 was used as a pressure-sensitive adhesive sheet 4 except that the separator 4 obtained above was used instead of the separator 1. Layer 4 was obtained.

(3) Production of optical film with separator film laminated pressure-sensitive adhesive layer (I) Example 1: Optical film A with separator film laminated pressure-sensitive adhesive layer
(I) Preparation of Polarizing Film (Polarizer) A Polyvinyl alcohol film (“Kuraray Poval Film VF-PE # 3000” having an average polymerization degree of about 2400, a saponification degree of 99.9 mol% and a thickness of 30 μm, Kuraray Co., Ltd. The product was immersed in pure water at 37 ° C., and then immersed in an aqueous solution containing iodine and potassium iodide (iodine / potassium iodide / water (weight ratio) = 0.04 / 1.5 / 100) at 30 ° C. Soaked. Then, it was immersed at 56.5 ° C. in an aqueous solution containing potassium iodide and boric acid (potassium iodide / boric acid / water (weight ratio) = 12 / 3.6 / 100). Next, the film was washed with pure water at 10 ° C. and then dried at 85 ° C. to obtain a polarizing film A having a thickness of about 12 μm in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.

(Ii) Preparation of optical film A Transparent protective film (“25KCHCN-TC”, letterpress printing) obtained by applying a 7 μm hard coat layer to a 25 μm thick triacetylcellulose film on one side of the obtained polarizing film (Made by Co., Ltd.) is bonded through an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin, and a cycloolefin-based resin film (“ZF14-023” having a thickness of 23 μm on the surface opposite to the transparent protective film, Japan An optical film A (polarizing plate, thickness: 67 μm) was prepared by pasting together.

The water absorption rate of the obtained optical film A was measured by the following method. The water absorption rate of the optical film A was 3.15%.
(Measurement method of water absorption)
After cutting the optical film into a size of 80 mm × 80 mm, the cut out test pieces are put together and put into a constant temperature and humidity chamber at a temperature of 23 ° C. and a relative humidity of 90% RH. Take out and measure the total weight (W _A ) of 5 test pieces. Next, the five test pieces after the weight measurement are put into an oven at a temperature of 95 ° C. in a dry atmosphere, taken out from the oven after 2 hours, and the total weight (W _B ) of the five test pieces is measured. From W _A and _{W B,} we obtain the water absorption by the following equation.
Water absorption rate = (W _A −W _B ) / W _B × 100 (%)

(Iii) Production of optical film (polarizing plate) on which pressure-sensitive adhesive layer is formed Separator of pressure-sensitive adhesive sheet 1 produced in (b1) above on the surface obtained by laminating the cycloolefin-based resin film of optical film A thus obtained. The opposite surface (adhesive layer surface) is pasted with a laminator, and then cured for 7 days at a temperature of 23 ° C. and a relative humidity of 65%. The adhesive layer and separator on one side of the optical film A (polarizing plate) Thus, an optical film A1 (a polarizing plate) with a separator film laminated pressure-sensitive adhesive layer having a structure in which 1 and 1 were laminated in this order was obtained.

Comparative Example 1
Instead of the pressure-sensitive adhesive sheet 1, the pressure-sensitive adhesive layer and the separator 2 are formed on one side of the optical film A (polarizing plate) in the same manner as in Example 1 except that the pressure-sensitive adhesive sheet 2 obtained in (b2) above was used. An optical film A2 (polarizing plate) with a separator film laminated pressure-sensitive adhesive layer having a constitution laminated in this order was obtained.

Comparative Example 2
Instead of the pressure-sensitive adhesive sheet 1, the pressure-sensitive adhesive layer and the separator 3 are formed on one side of the optical film A (polarizing plate) in the same manner as in Example 1 except that the pressure-sensitive adhesive sheet 3 obtained in (b3) above was used. Optical film A3 (polarizing plate) with a separator film laminated pressure-sensitive adhesive layer having a constitution laminated in this order was obtained.

Comparative Example 3
Instead of the pressure-sensitive adhesive sheet 1, the pressure-sensitive adhesive layer and the separator 4 are formed on one side of the optical film A (polarizing plate) in the same manner as in Example 1 except that the pressure-sensitive adhesive sheet 4 obtained in (b4) above was used. An optical film A4 (polarizing plate) with a separator film laminated pressure-sensitive adhesive layer having a constitution laminated in this order was obtained.

(4) Creep force at the interface between the separator film and the pressure-sensitive adhesive layer Each of the optical films A1 to A4 with the separator film laminated pressure-sensitive adhesive layer produced above was cut into a size of 110 mm × 15 mm, and cut out according to FIG. The separator film was cut on the left side of 7.5 mm from the center of the sample, and the optical film with the adhesive layer was cut on the right side of 7.5 mm from the center of the cut sample. One end of the long side of the test piece was attached to the upper chucking of a tensile tester (Autograph AG-1S MO (floor) type, manufactured by Shimadzu Corporation) so that the test piece was vertical. Furthermore, one end opposite to the side attached by upper chucking is attached to the lower chucking, and the lower chucking is moved downward at a moving speed of 1 mm / min until the moving distance becomes 5 mm. The maximum value of the required force was measured as the creep force.
The results are shown in Table 1.

3. Appearance evaluation of optical film with separator film laminated pressure-sensitive adhesive layer According to the following method, the appearance of the optical film with pressure-sensitive adhesive layer was evaluated according to the following method.
Each of the optical films A1 to A4 with the separator film laminated pressure-sensitive adhesive layer produced above was made into a size of 60 mm × 100 mm by a continuous automatic cutting machine “Super Cutter” (model number PN1-600) (pressing type) manufactured by Sugano Seiki Co., Ltd. A test piece was cut out and placed in a high-temperature and high-humidity tank having a temperature of 23 ° C. and a humidity of 65% RH for 144 hours (one week), and then the test piece was irradiated with fluorescent lamp light of 1200 lux or more from the separator film side. A visual inspection with reflected light was performed from a distance of about 300 mm to 500 mm away from the piece, and the presence or absence of extremely small streak-like wrinkles was confirmed. The results are shown in Table 1.

Appearance evaluation standard x: Generation of streak-like wrinkles having a width of about 0.5 mm to 2 mm and a depth of about 0.1 μm to 1 μm was confirmed.
◯: Generation of the above-mentioned streak-like wrinkles was not confirmed.

  In the optical film with the separator film laminated pressure-sensitive adhesive layer of Example 1 in which the separator film has a film thickness of 45 μm or more and the creep force at the interface between the separator film and the pressure-sensitive adhesive layer is 3 N or more, extremely small wrinkles Did not occur, and appearance did not deteriorate. On the other hand, in the optical film with the separator film laminated pressure-sensitive adhesive layer of Comparative Example 1 in which the film thickness of the separator film is less than 45 μm, even when the creep force is 3N or more, streaky wrinkles are generated and the appearance is poor. occured. Moreover, even if the film thickness of the separator film is 45 μm or more, the optical film with the separator film laminated pressure-sensitive adhesive layer of Comparative Example 2 in which the creep force is less than 3N causes streak-like wrinkles, resulting in poor appearance. . Furthermore, even in the optical film with the separator film laminated pressure-sensitive adhesive layer of Comparative Example 3 in which the film thickness of the separator film was less than 45 μm and the creep force was less than 3 N, streaky wrinkles were generated, resulting in poor appearance.

  1: optical film with separator film laminated pressure-sensitive adhesive layer, 2: polarizer, 3: (first) resin film, 4: (second) resin film, 5: protective film, 6: hard coat layer, 10: optical film , 20: adhesive layer, 30: separator film

Claims (4)

An optical film with a separator film laminated pressure-sensitive adhesive layer comprising a separator film (C) laminated on at least one surface of the optical film (A) via a pressure-sensitive adhesive layer (B),
An optical film with a separator film laminated pressure-sensitive adhesive layer, wherein the separator film (C) has a film thickness of 45 μm or more, and a creep force at the interface between the separator film (C) and the pressure-sensitive adhesive layer (B) is 3N or more.   The optical film with the separator film lamination adhesive layer according to claim 1 whose bending stiffness of a separator film (C) is 1 mg or more.   The optical film with a separator film laminated pressure-sensitive adhesive layer according to claim 1 or 2, wherein the water absorption of the optical film (A) is 2.0% or more.   The optical film with a separator film laminated adhesive layer according to any one of claims 1 to 3, wherein the film thickness of the optical film (A) is 100 µm or less.