TWI752054B - Optical film with pressure-sensitive adhesive layer laminated with separator film - Google Patents

Abstract

An object of the present invention is to provide an optical film with pressure-sensitive adhesive layer laminated with separator film, in which streak-like wrinkle is less likely to occur in a separator film and a pressure-sensitive adhesive layer under the separator film when being cut into chips or the like.

The optical film with pressure-sensitive adhesive layer laminated with separator film comprises a separator film (C) laminated on at least one side of an optical film (A) via a pressure-sensitive adhesive layer (B), wherein the film thickness of the separator film (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 3 N or more.

Description

Optical film with adhesive layer of laminated separation film

The present invention relates to an optical film with an adhesive layer on which a separation film is laminated, which is obtained by laminating a separation film on the optical film with an adhesive layer.

Optical films typified by polarizers in which a transparent resin film is laminated on one side or both sides of a polarizer are widely used as optical members constituting image display devices such as liquid crystal display devices. Optical films such as polarizers and retardation plates are, in most cases, constituted in the form of an "adhesive layer-attached optical film" with an adhesive layer on one side. It is used by being bonded to display elements such as liquid crystal cells and organic EL display elements. For such an optical film with an adhesive layer, in order to protect the adhesive layer before being attached to a display element, a separator film is usually laminated, and when the adhesive layer is used, the adhesive remains on the optical film. However, the separation membrane is peeled off and removed (Patent Document 1).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2009/069799

In recent years, there is a tendency for image display devices to be thinned, and therefore, optical films are expected to be thinner, for example, 100 μm or less. When an adhesive layer is provided on such a thin optical film and a separation film is laminated thereon to produce an "optical film with an adhesive layer laminated with a separation film", when the film is cut into, for example, a rectangular chip etc., there are cases in which extremely small streak-like wrinkles are generated in both the separation film and the adhesive layer below from the end of the small piece. The streak-like wrinkles generated in this way may move toward the inside (center part) of the small piece. In this way, when extremely small striated wrinkles are gathered in the central portion, the defects will become conspicuous.

Therefore, the object of the present invention is to provide an optical film with an adhesive layer attached to a layered separation film, which makes it difficult for the separation film and the adhesive layer below to produce extremely small striped wrinkles when cut into small pieces.

The inventors of the present invention have completed the present invention as a result of intensive examination in order to solve the above-mentioned problems.

That is, the present invention includes the following preferred aspects [1] to [4].

[1] An optical film to which an adhesive layer of a separation film is laminated, comprising: a separation film (C) laminated on at least one surface of an optical film (A) via an adhesive layer (B); wherein the separation film The film thickness of (C) is 45 μm or more, and the creep force at the interface between the separation membrane (C) and the adhesive layer (B) is: 3N or more.

[2] The optical film to which the adhesive layer of the separation membrane is laminated according to [1], wherein the flexural rigidity of the separation membrane (C) is 1 mg or more.

[3] The optical film to which the adhesive layer of the separation membrane is laminated according to [1] or [2], wherein the optical film (A) has a water absorption rate of 2.0% or more.

[4] The optical film to which the adhesive layer of the separation film is laminated according to any one of [1] to [3], wherein the optical film (A) has a film thickness of 100 μm or less.

According to the present invention, it is possible to provide an optical film with an adhesive layer of a layered separation film, which prevents the separation film and the adhesive layer thereunder from generating streak-like wrinkles when it is cut into small pieces or the like.

1‧‧‧Optical film with adhesive layer of laminated separation film

2‧‧‧Polarizer

3‧‧‧(1st) Resin film

4‧‧‧(2nd) Resin film

5‧‧‧Protective film

6‧‧‧Hard coating

10‧‧‧Optical Film

20‧‧‧Adhesive layer

30‧‧‧Separation membrane

Fig. 1 is a schematic cross-sectional view showing an example of an optical film to which the adhesive layer of the laminated separation film of the present invention is adhered.

Fig. 2 is a schematic cross-sectional view showing an example of an optical film to which an adhesive layer of the separation film of the present invention is adhered.

FIG. 3 is a schematic plan view and a schematic cross-sectional view showing a sample for creep force measurement of an optical film with an adhesive layer of a laminated separation membrane.

<Optical film with adhesive layer via laminated separation film>

The adhesive layer-adhered optical film of the layered separation film of the present invention comprises: an optical film (A); and a separation film (C) laminated on at least one surface of the optical film (A) via an adhesive layer (B) ).

In the adhesive layer-adhered optical film of the layered separation membrane of the present invention, the thickness of the separation membrane (C) is 45 μm or more. When the film thickness of the separation membrane (C) is less than 45 μm, extremely small streaks and wrinkles are likely to occur between the separation membrane and the adhesive layer below it. In the adhesive layer-adhered optical film of the layered separation membrane of the present invention, the thickness of the separation membrane (C) is preferably 47 μm or more. The upper limit of the film thickness of the separation membrane (C) is not particularly limited, but is usually 200 μm or less, and is preferably 150 μm or less, for example, from the viewpoint of making it easier to peel off the separation membrane from the adhesive layer. Preferably it is 100 micrometers or less.

In the adhesive layer-attached optical film of the laminated separation membrane of the present invention, the creep force (also referred to as creep force) of the interface between the separation membrane (C) and the adhesive layer (B) is 3N above. When the creep force of the interface between the separation film (C) and the adhesive layer (B) is less than 3N, the adhesive force between the separation film (C) and the adhesive layer (B) is weak, and when the optical film is cut into small pieces etc., it becomes easy to produce extremely small streak-like wrinkles from its ends. In addition, gaps tend to be formed between the separation membrane and the adhesive layer, so that the separation membrane tends to slip off from the adhesive layer, and streaks tend to progress toward the inside of the small pieces. In the adhesive layer-attached optical film of the layered separation membrane of the present invention, the creep force of the interface between the separation membrane (C) and the adhesive layer (B) is preferably 4N or more. The upper limit of the creep force at the interface between the separation membrane (C) and the adhesive layer (B) is not particularly limited, but is usually 15 N or less. If the separation membrane is to be easily peeled off from the adhesive layer, the For example, 12N or less is preferable, and 10N or less is more preferable. In addition, the said creep force is the value measured by the method described in the Example.

The creep force of the interface between the separation membrane (C) and the adhesive layer (B) can be determined by, for example, the peeling force of the separation membrane to the adhesive layer, or the The elastic modulus of the separation layer is controlled to a desired value. 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 term "optical film" refers to a film that functions for image display (display screen etc.) (for example, a film that functions to improve image visibility), and means that a liquid crystal can be incorporated Films with various optical properties of image display devices such as display devices, such as single-layer structures (polarizer, retardation film, brightness enhancement film, anti-glare film, anti-reflection film, diffusion film, condensing film and other optical functions film, etc.), or a multilayer structure (for example, a polarizing plate, a retardation plate, etc.). Furthermore, when the optical film has a multilayer structure, the layer (such as a protective film, etc.) that is finally peeled off when the optical film is incorporated into an optical laminate or a display device, etc., is not considered to constitute an optical film ( A) layer.

As long as the optical film with the adhesive layer attached to the laminated separation film of the present invention includes the optical film (A) and the separation film (C) laminated on at least one side of the optical film (A) via the adhesive layer (B), In addition, the structure is not limited as long as the structure can have the functions generally possessed by optical films. The optical film is preferably a polarizer, a polarizer, a retardation plate or a retardation film, and particularly preferably a polarizer or a polarizer.

For example, when the configuration of a preferred embodiment of the present invention is described with reference to FIGS. 1 and 2, the optical film 1 shown in FIG. The film 10 and the separation film 30 laminated on one side of the optical film via the adhesive layer 20 are constituted. Furthermore, in the optical film 10, the resin films 3 and 4 are laminated on both sides of the polarizer 2, Furthermore, the protective film 5 is layered on the area of the resin film 4 on the opposite side to the resin film having the adhesive layer 20 which is not in contact with the polarizer 2 . Furthermore, the optical film 1 with the adhesive layer on which the separation film is laminated as shown in FIG. 2 is composed of the optical film 10 and the separation film 30 laminated on one side of the optical film via the adhesive layer 20. In the film 10, the resin films 3 and 4 are laminated on both sides of the polarizer 2, and a hard coat layer is layered on the area of the resin film 4 on the opposite side to the resin film having the adhesive layer 20 that is not in contact with the polarizer 2 6. Furthermore, the 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 via an adhesive layer or an adhesive layer not shown.

Each layer (member) constituting the "optical film with an adhesive layer via a laminated separation membrane" of the present invention is not particularly limited, and can be appropriately determined in accordance with desired properties of the optical film. Hereinafter, with respect to each constituent component of the "optical film with an adhesive layer via a laminated separation membrane" of the present invention, a preferred aspect thereof will be described in detail.

[1] Optical film (A)

[1-1] Polarizing plate

In this specification, the so-called polarizing plate refers to a resin film or a resin layer layered on at least one area of a polarizer. A polarizer refers to 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 perpendicular to its absorption axis (parallel to the transmission axis). , for example, a film obtained by adsorbing and aligning a dichroic dye to a polyvinyl alcohol-based resin film can be used. As a dichroic dye, iodine, a dichroic organic dye, etc. are mentioned, for example.

Polyvinyl alcohol-based resin, usually by polyvinyl acetate It is obtained by saponification of alkenyl resin. The polyvinyl acetate-based resins include, for example, polyvinyl acetate which is a homopolymer of vinyl acetate; monomers copolymerizable with vinyl acetate (for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acid, (meth)acrylamide having an ammonium group, etc.) and a copolymer of vinyl acetate, etc.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 to 100 mol %, preferably 98 mol % or more. The polyvinyl alcohol-based resin may be modified, for example, aldehyde-modified polyvinyl formal (polyvinyl formal) or polyvinyl acetal (polyvinyl acetal). The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably about 1,500 to 5,000. In addition, the average degree of polymerization of polyvinyl alcohol-type resin can be calculated|required based on JISK6726.

Usually, a film formed by forming a polyvinyl alcohol-based resin into a film can be used as a raw material film of a polarizer. The polyvinyl alcohol-based resin can be formed into a film by a known method. The thickness of the raw material film is usually 1 to 150 μm, and is preferably 10 μm or more in consideration of ease of stretching and the like.

The polarizer includes, for example, a step of uniaxially extending a raw material 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 solution of boric acid, and a step of washing the film with water, and finally. It is made by drying it. In the present invention, the thickness of the polarizer is usually 1 to 50 μm, and from the viewpoint of thinning the optical film, preferably 30 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less.

A polarizer obtained by adsorbing and aligning a dichroic dye on a polyvinyl alcohol-based resin film can be obtained by the method of the following 1). It can be obtained by the method of the following 2): 1) a method in which a single film of a polyvinyl alcohol-based resin film is used as a raw material film, and the film is subjected to a uniaxial stretching treatment and a dyeing treatment of a dichroic dye; 2) a base The material film is coated with a coating solution (aqueous solution, etc.) containing a polyvinyl alcohol-based resin, and then dried to obtain a base film having a polyvinyl alcohol-based resin layer, and then uniaxially stretched together with the base film, and the stretched The method of peeling and removing the base film after performing the dyeing process of the dichroic dye on the polyvinyl alcohol-type resin layer after that. As the base film, a film made of the same thermoplastic resin as the thermoplastic resin that can be used as the resin film described later can be used. Preferably, it is a film composed of the following resins: polyester-based resins such as polyethylene terephthalate, polycarbonate-based resins, cellulose-based resins such as triacetyl cellulose, and norbornene-based resins Cyclic polyolefin-based resins, polystyrene-based resins, etc. When the method of the above-mentioned 2) is used, the production of the polarizer of the thin film can be facilitated, for example, the production of the polarizer with a thickness of 7 μm or less can also be facilitated.

The resin film may be, for example, a film composed of a thermoplastic resin having translucency (preferably optically transparent), such as a chain polyolefin-based resin (polyethylene-based resin, polypropylene-based resin, etc.), Polyolefin-based resins such as cyclic polyolefin-based resins (norbornene-based resins, etc.); fiber-based resins (cellulose ester-based resins, etc.); polyester-based resins (polyethylene terephthalate, polyethylene naphthalate, etc.) ethylene glycol, polybutylene terephthalate, etc.); polycarbonate resins (for example, polycarbonates derived from bisphenols such as 2,2-bis(4-hydroxyphenyl)propane, etc.); base) acrylic resin; styrene resin; polyether ether ketone resin; polysilicon resin, or mixtures, copolymers and the like of these. Among them, the resin film is preferably made of a cyclic polyolefin-based resin, a polycarbonate-based resin, a fiber-based resin, a polyester-based resin, a (meth)acrylic-based resin, or the like. The formed film is particularly preferably a film formed of a fiber-based resin, a cyclic polyolefin-based resin, or the like.

The chain polyolefin-based resin includes, for example, a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, or a copolymer composed of two or more kinds of chain olefins.

Cyclic polyolefin-based resins are resins containing, as polymerized units, cyclic olefins represented by norbornene, tetracyclododecane (alias: dimethanooctahydronaphthalene), or derivatives thereof. general term. Cyclic polyolefin-based resins include, for example, ring-opening (co)polymers of cyclic olefins and hydrogenated products thereof, addition polymers of cyclic olefins, cyclic olefins and chain olefins such as ethylene and propylene, or those containing ethylene. Copolymers of aromatic compounds based on unsaturated carboxylic acids, modified (co)polymers modified with unsaturated carboxylic acids or derivatives thereof, and the like. Among these, norbornene-based resins using norbornene-based monomers such as norbornene and polycyclic norbornene-based monomers as cyclic olefins are preferred.

Cellulose-based resin, preferably cellulose ester-based resin, that is, a partial or complete esterified product of cellulose, etc., for example, cellulose acetate, propionate, butyrate, mixed esters of these, and the like are exemplified . Among these, triacetoxycellulose, diacetoxycellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like are more preferred.

The polyester-based resin is a resin other than the above-mentioned cellulose ester-based resin having an ester bond, and is generally composed of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. Polyester-based resins include, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene terephthalate Butylene naphthalate, polypropylene terephthalate, polypropylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate, etc.

The polycarbonate resin is a polyester formed of carbonic acid and diol or bisphenol. Among these, from the viewpoint of heat resistance, weather resistance, and acid resistance, an aromatic polycarbonate having a diphenylalkane in a molecular chain is preferred. Polycarbonates include, for example, 2,2-bis(4-hydroxyphenyl)propane (alias: bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl) Polycarbonates derived from bisphenols such as -hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane, and 1,1-bis(4-hydroxyphenyl)ethane.

The (meth)acrylic resin that can constitute the resin film may be a polymer mainly composed of a structural unit derived from methacrylate (for example, 50% by weight or more), and is preferably copolymerized with other copolymerization components. formed copolymer. The (meth)acrylic resin may contain two or more methacrylate-derived structural units. _{The methacrylates include, for example, C 1} to C ₄ alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

As a copolymerization component which can be copolymerized with methacrylate, acrylate is mentioned, for example. _{The acrylate is preferably a C 1} to C ₈ alkyl ester of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Specific examples of other copolymerization components include unsaturated carboxylic acids such as (meth)acrylic acid; aromatic vinyl compounds such as styrene, halogenated styrene, α-methylstyrene, and vinyltoluene; (methyl) ) vinyl cyanide such as acrylonitrile; unsaturated carboxylic acid anhydrides such as maleic anhydride and methyl maleic anhydride; unsaturated carboxylic acid anhydrides such as phenylmaleimide and cyclohexylmaleimide Compounds other than acrylates having one polymerizable carbon-carbon double bond in the molecule, such as imide. 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 from the viewpoint of improving the durability of the film. 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, for example, a glutaric anhydride structure, a succinic anhydride structure, and the like; As a specific example, a butyrolactone ring structure, a valerolactone ring structure, etc. are mentioned.

The (meth)acrylic resin may contain acrylic rubber particles from the viewpoints of film formability to a film, impact resistance of the film, and the like. The so-called acrylic rubber particles refer to particles that have an elastic polymer mainly composed of acrylic ester as an essential component, for example, a single-layer structure composed of substantially only the elastic polymer, or an elastic polymer A multi-layer constructor that makes 1 layer. Examples of the elastic polymer include, for example, a cross-linked elastic copolymer containing an alkyl acrylate as a main component and copolymerized with other vinyl-based monomers and cross-linkable monomers that can be copolymerized therewith. _{Examples of the alkyl acrylate to be the main component of the elastic polymer include C 1} to C ₈ alkyl acrylates of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The number of carbon atoms in the alkyl group is preferably 4 or more.

As for other vinyl monomers that can be copolymerized with acrylates, for example, compounds having one polymerizable carbon-carbon double bond in the molecule can be mentioned, More specifically, methacrylates, such as methyl methacrylate, aromatic vinyl compounds, such as styrene, vinyl cyanide, such as (meth)acrylonitrile, etc. are mentioned, for example. The crosslinkable monomer includes, for example, a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule, more specifically, ethylene glycol di(meth)acrylate, butanediol Polyol (meth)acrylate such as di(meth)acrylate, allyl (meth)acrylate such as allyl (meth)acrylate, divinylbenzene, and the like.

The content of the acrylic rubber particles is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of the (meth)acrylic resin. When the content of the acrylic rubber particles is too large, the surface hardness of the film decreases, and when the film is subjected to surface treatment, the solvent resistance to the organic solvent in the surface treatment agent may decrease. Therefore, 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 may contain usual additives in the technical field of the present invention. Examples of additives include ultraviolet absorbers, infrared absorbers, organic dyes, pigments, inorganic dyes, antioxidants, antistatic agents, surfactants, lubricants, dispersants, thermal stabilizers, and the like. As an ultraviolet absorber, a salicylate compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyano (meth)acrylate compound, a nickel zirconium salt etc. are mentioned, for example.

The resin film may be an unstretched film, or a monoaxially or biaxially stretched film. The resin film may be a protective film responsible for protecting the polarizer, or may be a protective film having an optical function such as a retardation film described later. Again Alternatively, when the polarizing plate includes a plurality of resin films, the resin films may be the same or different films.

Furthermore, the resin film may have surface treatment layers such as a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, an antistatic layer, an antifouling layer, a conductive layer, etc. on the outer surface (the surface opposite to the polarizer) ( coating layer). The thickness of the resin film is usually 1 to 70 μm, preferably 5 to 50 μm, and may be 30 μm or less.

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

Examples of the water-based adhesive include conventional water-based adhesives (for example, adhesives composed of a polyvinyl alcohol-based resin aqueous solution, water-based two-component urethane-based emulsion adhesives, aldehyde compounds, epoxy compounds, and melamine-based adhesives). compounds, methylol compounds, isocyanate compounds, amine compounds, cross-linking agents such as polyvalent metal salts, etc.). Among these, a water-based adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin can be suitably used. Furthermore, when an aqueous adhesive is used, after bonding the polarizer and the resin film, it is preferable to perform a drying step in order to remove the water contained in the aqueous adhesive. After the drying step, for example, an aging step of aging at a temperature of about 20 to 45° C. can be provided.

The above-mentioned active energy ray-curable adhesive refers to an adhesive that is cured by irradiating an active energy ray such as ultraviolet rays or electron beams, and examples thereof include a curable composition containing a polymerizable compound and a photopolymerization initiator, a photoreaction Curable composition of resin, including binder resin and light The curable composition of the reactive crosslinking agent, etc., is preferably an ultraviolet curable adhesive.

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

The method of bonding a polarizer and a resin film together, for example, the method of performing surface activation treatment, such as saponification treatment, corona treatment, and plasma treatment, on the bonding surface of at least one of these, etc. are mentioned. When bonding resin films on both sides of the polarizer, the adhesive for bonding these resin films may be the same type of adhesive or different types of adhesive.

For the polarizing plate, other films or layers may be further laminated. Specific examples thereof include, in addition to the retardation film described later, a brightness enhancement film, an anti-glare film, an anti-reflection film, a diffusion film, a light-converging film, and an adhesive layer other than the adhesive layer (B), a coating layer, and a protective layer. film etc. The protective film is a film used for the purpose of protecting the surface of an optical film such as a polarizing plate from damage and contamination. Generally, the optical film with an adhesive layer is attached to, for example, a metal layer or a substrate, and then peeled off and removed. Of.

The protective film is usually composed of a base film and an adhesive layer laminated thereon. The base film can be made of thermoplastic resins (for example, polyolefin-based resins such as polyethylene-based resins and polypropylene-based resins; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate-based resins). resin; (meth)acrylic resin, etc.).

[1-2] Phase difference plate

In this specification, the so-called retardation plate refers to a resin film or a resin layer layered on at least one area of a retardation film. The retardation film included in the retardation plate is an optical film showing optical anisotropy, which can be a stretched film obtained by extending a resin film composed of the following resins to about 1.01 to 6 times: In addition to the thermoplastic resins exemplified above in the case of resin films, for example, polyvinyl alcohol-based resins, polyarylate-based resins, polyimide-based resins, polyether-based resins, polyvinylidene fluoride/polyethylene Methyl methacrylate resin, liquid crystal polyester resin, ethylene-vinyl acetate copolymer saponification, polyvinyl chloride resin, etc. Among these, a polycarbonate-based resin film, a cyclic olefin-based resin film, a (meth)acrylic-based resin film, or a cellulose-based resin film is preferably stretched uniaxially or biaxially stretched. Moreover, in this specification, a zero retardation film (zero retardation film) is also included in retardation film (only can 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 can also be applied as a retardation film.

Called zero retardation film, retardation value R _e and R _th retardation value in the thickness direction are both within -15 to 15nm mean film plane. This retardation film is suitable for use in an IPS mode liquid crystal display device. R _e in-plane retardation value and the thickness direction retardation value R _th line are all preferably 10 to 10nm, more preferably 5 to 5nm. Here, the in-plane retardation value Re and the thickness direction retardation value R _th refer to values at a wavelength of 590 nm.

In-plane retardation and thickness direction retardation R _e and R _th value defined by the following formula _{based: R e = (n x -n} y) × d

R _th =[(n _x + _ny )/2-n _z ]×d In the formula, n _x is the refractive index in the slow axis direction (x-axis direction) in the _{film plane, and ny} is the fast axis in the film plane The refractive index in the direction (y-axis direction perpendicular to the x-axis in the plane), n _z 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.

For the zero retardation film, polyolefin resins such as cellulose-based resins, linear polyolefin-based resins, and cyclic polyolefin-based resins, polyethylene terephthalate-based resins, or (meth)acrylic-based resins can be used. Resin film, etc. made of resin. In particular, since the retardation value can be easily controlled and obtained, it is preferable to use a cellulose-based resin, a polyolefin-based resin, or a (meth)acrylic-based resin.

Furthermore, a film expressing optical anisotropy by coating and alignment of a liquid crystalline compound, or a film expressing optical anisotropy by coating an inorganic layered compound can also be used as a retardation film. Such retardation films are called temperature-compensated retardation films, and there are also films with oblique alignment of rod-shaped liquid crystals sold by JX Nippon Mining & Energy Co., Ltd. under the trade name "NH FILM". Disk-shaped liquid crystal tilt-aligned films sold under the trade name "WV FILM" by Fuji Film Co., Ltd., and fully biaxially oriented films sold under the trade name "VAC FILM" by Sumitomo Chemical Co., Ltd. A film, a biaxially oriented film, etc., also sold by Sumitomo Chemical Co., Ltd. under the trade name of "new VAC FILM". Furthermore, the resin film laminated on at least one side of the retardation film may be, for example, the above-mentioned protective film.

In general, when the film thickness of the optical film (A) constituting the "optical film with an adhesive layer through which a separation film is laminated" is thin, the separation film and the adhesive layer below it are likely to have extremely small streak-like wrinkles. Specifically, it is a wrinkle having a length of about 1 mm to 30 mm, a width of about 0.5 mm to 2 mm, and a depth of about 0.1 μm to 1 μm. In addition, when such a striped wrinkle is cut into a small piece, it may move from the cut surface side to the center portion over time. Such wrinkles are more likely to occur when the thickness of the optical film (A) is thinner. Therefore, the thinner the film thickness of the optical film (A) constituting the "optical film with an adhesive layer on which the separation film is laminated" is, the more the effect of suppressing the occurrence of the aforementioned wrinkles can be exhibited. Therefore, the thickness of the optical film (A) constituting the "optical film with an adhesive layer through a laminated separation film" of the present invention is usually 100 μm or less, preferably 80 μm or less, and more preferably 70 μm or less. Furthermore, the lower limit of the thickness of the optical film (A) is usually 5 μm or more, and from the viewpoint of the handleability (that is, ease of handling) of the optical film (A), for example, it is preferably 10 μm or more, and more preferably 15 μm or more.

Here, in the present invention, the so-called "film thickness of the optical film (A)" refers to the thickness of the single layer when the optical film has a single-layer structure, and refers to the thickness of the single layer when the optical film has a multilayer structure. The sum of the thicknesses of all layers. Furthermore, when the optical film has a multilayer structure, when the optical film is incorporated into an optical laminate or a display device, etc., the layer (such as a protective film, etc.) that is finally peeled off is not regarded as constituting the optical film (A). ) is not considered when calculating the film thickness of the optical film (A). Therefore, for example, in the optical film with the adhesive layer of the separation film laminated as 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 thickness. and, In the optical film with the adhesive layer of the laminated separation film shown in Fig. 2, the film thickness of the optical film (A) is the polarizer 2, the first resin film 3, the second resin film 4 and the hard coat layer 6. total thickness.

In this invention, the effect of suppressing generation|occurrence|production of the said extremely small wrinkle can also be heightened by balancing the film thickness of the separation film (C) and the film thickness of the optical film (A). For example, than the thickness T _A T _C of the optical film thickness of the separation membrane (T _C / T _A), it is preferably 0.4 or more, more preferably 0.6 or more, and particularly preferably 0.7 or more. The ratio (T _C / T _A) is generally 4 or less.

In general, when the water absorption rate of the optical film (A) constituting the "optical film with an adhesive layer through a laminated separation film" is high, the dimensional change of the optical film (A) due to water absorption is likely to occur. Propensity for extremely small streaks. Since such wrinkles can be suppressed, the effect of suppressing such wrinkles is high in the "optical film with an adhesive layer through a laminated separation film" of the present invention, and the optical film constituting the "optical film with an adhesive layer through a laminated separation film" The water absorption of the film (A) is, for example, 2.0% or more, and even if it is 3.0% or more, the occurrence of the aforementioned wrinkles can be effectively suppressed. In addition, the water absorption rate of an optical film (A) can be measured by the method described in the Example, for example, and it is 10 % or less normally.

The water absorption rate of the optical film (A) varies, for example, with each film constituting the optical film (A). For example, when the optical film is a polarizing plate, it depends on the material and thickness of the polarizer constituting it, and the material and thickness of the resin film attached thereon. For example, when the polarizer is a polyvinyl alcohol-based resin, the thickness of the polarizer is greater The thicker the film, the larger the water absorption rate. For example, when a cellulose-based resin film is used as the resin film, the thicker the thickness, the larger the water absorption rate is. Therefore, the water absorption rate of the optical film (A) can be determined by the materials and thicknesses constituting the various films. control.

[2] Adhesive layer (B)

The adhesive constituting the "adhesive layer (B) laminated on at least one side of the optical film (A) of the present invention (the adhesive layer 20 in Figs. 1 and 2)" can be conventionally used without particular limitation. As known adhesives, for example, adhesives having matrix polymers such as acrylic, rubber, urethane, polysilicone, and polyvinyl ether can be used. Moreover, an energy ray hardening type adhesive agent, a thermosetting type adhesive agent, etc. may be sufficient. Among these, the adhesive which uses an acrylic resin which is excellent in transparency, adhesive force, reworkability, weather resistance, heat resistance, etc. as a matrix polymer is suitable. In a preferred embodiment of the present invention, the adhesive layer (B) is composed of an adhesive composition comprising a (meth)acrylic resin (a), a crosslinking agent (b), and a silane compound (c). composed of reaction products.

[2-1] (Meth)acrylic resin (a)

(式中，R¹⁰表示氫原子或甲基，R²⁰表示碳數1至20的烷基，該烷基可具有直鏈狀、分支狀或環狀的任一構造，該烷基 的氫原子可被碳數1至10的烷氧基取代)。 In the present invention, the (meth)acrylic resin (a) that may be contained in the adhesive composition constituting the adhesive layer (B) is preferably derived from (a) represented by the following formula (I). A polymer (hereinafter also referred to as "(meth)acrylate polymer") containing a structural unit of alkyl) acrylate (hereinafter also referred to as structural unit (I)) as a main component (for example, containing 50% by weight or more thereof) :

(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 may have any structure of linear, branched or cyclic, and the hydrogen atom of the alkyl group may be substituted by an alkoxy group having 1 to 10 carbon atoms).

In addition, in this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid, and "(meth)", such as (meth)acrylate, also means the same.

The (meth)acrylate represented by the formula (I) includes, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, n-hexyl acrylate, isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, n- and iso-nonyl acrylate, n-decyl acrylate, isodecyl acrylate, n-dodecyl acrylate, cyclohexyl acrylate, isobornyl acrylate, stearyl acrylate, 3rd butyl acrylate, etc. Examples of the alkoxy-containing alkyl acrylate include, for example, 2-methoxyethyl acrylate, ethoxymethyl acrylate, and the like.

The (meth)acrylate polymer may contain two or more structural units (I). Furthermore, from the viewpoint of achieving both adhesiveness and durability, it is preferable to include a structural unit having a glass transition temperature Tg of the homopolymer of 0°C or higher and a structure having a glass transition temperature Tg of the homopolymer of less than 0°C unit of copolymers. The structural unit whose glass transition temperature (Tg) of the homopolymer is 0° C. or higher includes, for example, methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, and the like. From the viewpoint of durability, methyl acrylate is preferably included. ester or isobornyl acrylate. The structural unit whose glass transition temperature Tg of the homopolymer is less than 0°C includes, for example, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, and n-hexyl acrylate. ester, isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, propylene Isooctyl enoate, 2-ethylhexyl acrylate, n-nonyl acrylate, isononyl acrylate, n-decyl acrylate, isodecyl acrylate, n-dodecyl acrylate, etc., preferably n-butyl acrylate ester or 2-ethylhexyl acrylate, particularly preferred ones include n-butyl acrylate.

The (meth)acrylate polymer may contain structural units derived from other monomers other than the structural unit (I). The structural units derived from other monomers may be one type or two or more types. Specific examples of other monomers that the (meth)acrylate polymer may contain are shown below.

1) Monomers with polar functional groups

The (meth)acrylate polymer may contain a structural unit derived from a monomer having a polar functional group. As a monomer which has a polar functional group, the (meth)acrylate which has a polar functional group is mentioned, for example. As a polar functional group, a hydroxyl group, a carboxyl group, a substituted amine group, an unsubstituted amine group, etc. are mentioned, for example. As a polar functional group, heterocyclic groups, such as an epoxy group, etc. are mentioned, for example. Specific examples of the (meth)acrylate having such a polar functional group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxy (meth)acrylate. Butyl ester, 2-(2-hydroxyethoxy)ethyl (meth)acrylate, 2-chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate , Diethylene glycol mono(meth)acrylate and other monomers with hydroxyl groups; Acryloyl morpholine, vinyl caprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, (methyl) Tetrahydrofuran methyl acrylate, caprolactone-modified tetrahydrofuran methyl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran, etc. Monomers with heterocyclic groups; (meth)acrylic acid aminoethyl ester, (meth)acrylic acid N,N-dimethylaminoethyl ester, (meth) Monomers with substituted or unsubstituted amine groups such as dimethylaminopropyl acrylate; monomers with carboxyl groups such as (meth)acrylic acid and carboxyethyl (meth)acrylate. Among them, a monomer having a hydroxyl group is preferred, and a (meth)acrylate having a hydroxyl group is more preferred from the viewpoint of the reactivity of the (meth)acrylic resin (a) and the crosslinking agent.

The (meth)acrylate polymer may contain the above-mentioned other monomers having a polar functional group in total with the (meth)acrylate having a hydroxyl group. From the viewpoint of enhancing the peeling force, it is preferable that the monomer having an amine group is not substantially contained. Here, "substantially not included" means 1.0 part by mass or less in 100 parts by mass of all the constituent units constituting the (meth)acrylic resin (a). Furthermore, from the viewpoint of improving the corrosion resistance to transparent electrodes such as ITO, it is preferable that the monomer having a carboxyl group is not substantially contained. Here, "substantially not contained" means 2.0 parts by mass or less in 100 parts by mass of all the constituent 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)acrylate polymer is preferably 20 parts by mass or less with respect to 100 parts by mass of the total structural units of the (meth)acrylate polymer, It is more preferably 0.1 part by mass or more and 20 parts by mass or less, still more preferably 0.1 part by mass or more and 10 parts by mass or less, and particularly preferably 0.5 part by mass or more and 10 parts by mass or less.

2) Monomers with aromatic groups

The (meth)acrylate polymer may contain a structural unit derived from a monomer having an aromatic group. Monomers having an aromatic group, such as intramolecular A (meth)acrylate having one (meth)acryloyl group and one or more aromatic rings (eg, a benzene ring, a naphthalene ring, etc.) and having a phenyl group, a phenoxyethyl group, or a benzyl group. By including these structural units, the white spot phenomenon of the polarizing plate during the durability test can be suppressed.

The (meth)acrylate having a phenoxyethyl group includes, for example, 2-phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, Ethylene oxide-modified nonylphenol ester of (meth)acrylic acid, 2-(o-phenylphenoxy)ethyl (meth)acrylate, and the like. As a structural unit which has a benzyl group, benzyl acrylate etc. are mentioned, for example. Among them, 2-phenoxyethyl (meth)acrylate and 2-(2-phenoxyethoxy)ethyl (meth)acrylate are preferred from the viewpoint of vitiligo suppression.

The content of the structural unit derived from the monomer having an aromatic group in the (meth)acrylate polymer is preferably 50 parts by mass or less with respect to 100 parts by mass of all the structural units of the (meth)acrylate polymer, More preferably, it is 4 parts by mass or more and 50 parts by mass or less, and still more preferably 4 parts by mass or more and 25 parts by mass or less.

3) Acrylamide monomers

The (meth)acrylate polymer may contain a structural unit derived from a monomer having an acrylamide group. Examples of monomers having an acrylamide group include N-methylol acrylamide, N-(2-hydroxyethyl) acrylamide, N-(3-hydroxypropyl) acrylamide, N-( 4-Hydroxybutyl) acrylamide, 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) Acrylonitrile Amine, N-[2-(2-Oxy-1-imidazolidinyl)ethyl]acrylamido, 2-acrylamido-2-methyl-1-propanesulfonic acid, N-(methyl) Oxymethyl) acrylamide, N-(ethoxymethyl) acrylamide, N-(propoxymethyl) acrylamide, N-(1-methylethoxymethyl) acrylamide Amine, N-(1-methylpropoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide [alias: N-(isobutylmethyl)acrylamide], N-(Butoxymethyl)acrylamide, N-(1,1-dimethylethoxymethyl)acrylamide, N-(2-methoxyethyl)acrylamide, N- (2-ethoxyethyl) acrylamide, N-(2-propoxyethyl) acrylamide, N-[2-(1-methylethoxy)ethyl] acrylamide, N- -[2-(1-Methylpropoxy)ethyl]acrylamide, N-[2-(2-methylpropoxy)ethyl]acrylamide [alias: N-(isobutoxy) ethyl) acrylamide], N-(2-butoxyethyl) acrylamide, N-[2-(1,1-dimethylethoxy)ethyl] acrylamide and the like. By including these structural units, bleeding of additives such as antistatic agents can be suppressed. Among them, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(butoxymethyl)acrylamide are preferably used. methyl) acrylamide, N-(2-methylpropoxymethyl) acrylamide and the like.

In addition, structural units derived from other monomers other than the structural unit (I) include, for example, structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, and structural units derived from having a plurality of (methyl) groups in the molecule. Structural unit of acrylyl monomer, etc.

Styrenic monomers, for example: styrene; such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene Styrene, butyl styrene, hexyl styrene, heptyl styrene, octyl styrene and other alkyl styrenes; such as Halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene, etc.; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene, etc.

Examples of vinyl monomers include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, and other fatty acid vinyl esters; halogenated vinyl chloride, vinyl bromide, and the like Ethylene; halogenated vinylidene such as vinylidene chloride; nitrogen-containing heteroaromatic ethylene such as vinylpyridine, vinylpyrrolidone, vinylcarbazole; conjugated dienes such as butadiene, isoprene, chloroprene, etc. ; and unsaturated nitriles such as acrylonitrile and methacrylonitrile.

Examples of monomers having a plurality of (meth)acryloyl groups in the molecule include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-Nanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, Monomers with 2 (meth)acryloyl groups in the molecule such as tripropylene glycol di(meth)acrylate; 3 (meth)acryloyl groups in the molecule such as trimethylolpropane tri(meth)acrylate base monomers, etc.

The weight average molecular weight (Mw) of the (meth)acrylic resin (a) is preferably from 500,000 to 2,500,000. When the weight average molecular weight is 500,000 or more, the durability of the adhesive layer in a high humidity and heat environment can be improved. When the weight average molecular weight is 2,500,000 or less, the handleability at the time of applying the adhesive solution is improved. The molecular weight distribution (Mw/Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 2 to 10. The weight average molecular weight can be analyzed by gel permeation chromatography (GPC), which is a Calculate the value for standard polystyrene.

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

The glass transition temperature of the (meth)acrylic resin (a) is preferably from -10°C to -60°C from the viewpoint of achieving both adhesiveness and durability. In addition, glass transition temperature can be measured by a differential scanning calorimeter (DSC).

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

As a polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, etc. are mentioned, for example. As a photopolymerization initiator, 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-propyl) ketone etc. are mentioned, for example. Thermal polymerization initiator, for example: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane Alkane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2 -Hydroxymethylpropionitrile) and other azo compounds; such as lauryl peroxide, 3rd butyl peroxide, benzyl peroxide, 3rd butyl peroxide benzoate, cumene hydroperoxide, Diisopropyl peroxydicarbonate, Dipropyl peroxydicarbonate, 3rd butyl peroxyneodecanoate, 3rd butyl peroxypivalate, (3,5,5-trimethylhexanyl peroxide) base) and other organic peroxides; such as potassium persulfate, ammonium persulfate, hydrogen peroxide and other inorganic peroxides. Furthermore, a redox-based initiator or the like in which a peroxide and a reducing agent are used in combination 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 in a nitrogen atmosphere. By stirring the obtained mixture at about 40 to 90° C. (preferably about 60 to 80° C.) for about 3 to 10 hours, a (meth)acrylate polymer can be obtained. In order to control the polymerization reaction, the monomer, the thermal polymerization initiator, or both may be added to the reaction system continuously or intermittently during the polymerization reaction, or may be added in a state of being dissolved in an organic solvent. Examples of organic solvents include: aromatic hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; aliphatic alcohol solvents such as propanol and isopropanol; acetone, methyl ethyl ketone, Ketone solvents such as methyl isobutyl ketone.

The (meth)acrylic resin (a) may contain two or more (meth)acrylate polymers. As such a (meth)acrylate polymer, for example, the structural unit (I) derived from the (meth)acrylate as the main component and the weight average molecular weight of the lower molecular weight in the range of 50,000 to 300,000 can be mentioned. (Meth)acrylate polymers.

[2-2] Cross-linking agent (b)

The adhesive composition for forming the adhesive layer (B) preferably contains a crosslinking agent (b). The cross-linking agent (b) can be, for example, conventional cross-linking agents (such as isocyanate compounds, epoxy compounds, aziridine compounds, metal chelates, peroxides, etc.), especially from adhesive compositions. From the viewpoints of the pot life and the durability of the optical film to which the pressure-sensitive adhesive layer is attached, the crosslinking speed, and the like, an isocyanate-based compound is preferred.

The isocyanate-based compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, such as aliphatic isocyanate-based compounds (such as hexamethylene diisocyanate), alicyclic isocyanate-based compounds (such as Isophorone diisocyanate), aromatic isocyanate-based compounds (such as tolylylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene base diisocyanate, triphenylmethane triisocyanate, etc.) and the like. Further, the crosslinking agent (b) may be an adduct (adduct) of the polyol compound of the above-mentioned isocyanate compound [for example, an adduct of glycerol, trimethylolpropane, etc.], an isocyanurate (isocyanurate) Compounds, biuret-type compounds; amines obtained by addition reaction with polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc. Derivatives such as ester prepolymer type isocyanate compounds. The crosslinking agent (b) may be used alone or in combination of two or more. Among them, from the viewpoint of durability, tolylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and polyolization of these are preferred compounds or these trimeric isocyanate compounds.

The ratio of the crosslinking agent (b) may be, for example, 0.01 to 10 parts by mass (for example, 0.05 to 5 parts by mass), preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin (a). (for example, 0.1 to 2 parts by mass), more preferably 0.1 to 1 part by mass (for example, 0.1 to 0.8 parts by mass). When it is below the upper limit value, it contributes to the improvement of durability (peeling resistance), and when it is more than the lower limit value, it contributes to the improvement of foaming resistance and heavy workability.

[2-3] Silane compound (c)

The adhesive composition contains the silane compound (c). Thereby, the adhesiveness of an adhesive bond layer and a glass substrate etc. can be improved. Two or more types of silane compounds (c) may also be used.

Silane compound (c), for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane Silane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethyl Silane, 2-(3,4-Epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methylpropene Oxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc.

The silane compound (c) may contain a polysiloxane oligomer type. Specific examples of polysiloxane oligomers, when expressed in the form of a combination of monomers, are as follows: 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3- mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer and other oligomers containing mercaptopropyl; mercaptomethyl Trimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer Methyltriethoxysilane-tetraethoxysilane oligomer and other oligomers containing mercaptomethyl group; 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3- Glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxy Propyltriethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyl Methyldimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyl Copolymers containing 3-glycidoxypropyl such as methyldiethoxysilane-tetraethoxysilane copolymer; 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer polymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane Silane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane- Tetramethoxysilane oligomers, 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomers and other oligomers containing methacryloyloxypropyl groups; 3-Propenyloxy Propyltrimethoxysilane-tetramethoxysilane oligomer, 3-propenyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-propenyloxypropyltriethoxy Silane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane- Tetramethoxysilane oligomer, 3-propenyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-propenyloxypropylmethyldiethoxysilane- Oligomers containing acryloxypropyl groups such as tetramethoxysilane oligomers, 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomers; vinyltrimethoxysilane Silane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane Silane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, Vinylmethyldiethoxysilane-tetramethoxysilane oligomer, vinylmethyldiethoxysilane-tetraethoxysilane oligomer and other vinyl-containing oligomers; 3-amino group Propyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane Silane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyl Propylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldiethyl Amino group-containing copolymers such as oxysilane-tetraethoxysilane copolymers, etc.

the content of the silane compound (c) in the adhesive composition, With respect to 100 parts by mass of (meth)acrylic resin (a), it is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and still more preferably 0.1 to 1 part by mass share. When the content of the silane compound (c) is 0.01 part by mass or more, the effect of improving the adhesion between the adhesive layer and the substrate (glass or transparent electrode) is easily obtained. Furthermore, when the content is 10 parts by mass or less, oozing of the silane compound (c) from the adhesive layer can be suppressed.

[2-4] Antistatic agent

The adhesive composition forming the adhesive layer (B) may further contain an antistatic agent. By including an antistatic agent, the antistatic properties of the optical film to which the adhesive layer of the separation film is laminated can be improved, for example, when the separation film is peeled off, or a protective film can be prevented from being further adhered to the optical film side. Defects due to static electricity generated during peeling, etc.

As the antistatic agent, for example, those conventionally used may be mentioned, and an ionic antistatic agent is preferred. As a cationic component which comprises an ionic antistatic agent, an organic cation, an inorganic cation, etc. are mentioned, for example. The organic cations include, for example, pyridinium cations, imidazolium cations, ammonium cations, pyrrolidinium cations, piperidinium cations, pernium cations, phosphonium cations, and the like. Examples of inorganic cations include alkali metal cations such as lithium cations, potassium cations, sodium cations, and cesium cations; and alkaline earth metal cations such as magnesium cations and calcium cations. The anion component constituting the ionic antistatic agent may be either an organic anion or an inorganic anion, but is preferably an anion component containing a fluorine atom from the viewpoint of good antistatic function. 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) Acyl) imide anion [(FSO ₂ ) ₂ N ^- ], tetrakis (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.

From the viewpoint of good temporal stability of the antistatic function of the adhesive composition, an ionic antistatic agent that is solid at room temperature is preferred. 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 4 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin (a).

[2-5] Other ingredients

The adhesive composition forming the adhesive layer (B) may contain one or more of solvents, cross-linking catalysts, ultraviolet absorbers, weather stabilizers, tackifiers, plasticizers, softeners, dyes, Additives such as pigments, inorganic fillers, light-scattering fine particles, and rust inhibitors. Furthermore, an ultraviolet curable compound is prepared in an adhesive composition, and after forming an adhesive layer, it is useful to irradiate an ultraviolet-ray to harden it, and it is useful for making a harder adhesive layer.

The thickness of the adhesive layer is usually 2 to 40 μm, which is determined from “durability of the optical film to which the adhesive layer of the separation film is laminated”, or “the optical film is attached to the adhesive layer exposed by peeling the separation film”. After fitting into the liquid crystal cell, etc., in the so-called rework operation in which the optical film is peeled off from the liquid crystal cell for some reason, the optical film with the adhesive layer can be peeled off from the liquid crystal cell with a slight force, and it is not easy to occur. From the viewpoint of the so-called "residual glue" phenomenon in which the adhesive remains on the liquid crystal cell side, rework becomes easy", it is preferably 5 to 30 μm, more preferably 10 to 25 μm. When it is below the said upper limit value, the durability of the optical film with an adhesive bond layer becomes favorable, and when it is more than the lower limit value, reworkability becomes favorable.

[3] Separation membrane (C)

It is preferable that the separation membrane (C) constituting the "optical film with an adhesive layer through which the separation membrane is laminated" of the present invention has a bending stiffness of 1 mg or more. When the bending stiffness is 1 mg or more, the generation of extremely small striae wrinkles can be suppressed more effectively. In the present invention, the flexural rigidity of the separation membrane (C) is more preferably 1.5 mg or more. The upper limit of the flexural rigidity of the separation membrane (C) is usually 100 mg or less, preferably 50 mg or less, and more preferably 30 mg or less, in order to facilitate the peeling of the separation membrane when the separation membrane is peeled off. In addition, the said bending rigidity is the value measured by the method described in the Example.

The flexural rigidity of the separation membrane (C) can be controlled to a desired range by, for example, the thickness of the plastic membrane constituting the separation membrane, or the film-forming conditions (especially the stretching conditions). Specifically, for example, the flexural rigidity can be increased by increasing the thickness of the base material or increasing the tensile modulus of elasticity of the base material.

In the present invention, the separation membrane (C) is preferably composed of a plastic film and a peeling layer. Examples of the plastic film include polyester films such as polyethylene terephthalate films, polybutylene terephthalate films, and polyethylene naphthalate films, and polyolefin films such as polypropylene films. Among them, polyethylene terephthalate films are preferred from the viewpoints of optical properties and quality, and polyethylene terephthalate films biaxially stretched are preferred because of their excellent dimensional stability. membrane. In addition, the release layer can be formed from, for example, a composition for forming a release layer, and the main component (resin) constituting the composition for forming a release layer is not particularly limited, and examples thereof include silicone resin, alkyd resin, and acrylic resin. And long-chain alkyl resins, etc. Among them, the polysiloxane resin is preferable.

Silicone resin, for example, with dimethylpolysiloxane A polysiloxane resin with alkane as the basic skeleton. Furthermore, polysiloxane resins include addition reaction type, condensation reaction type, ultraviolet curing type, electron beam curing type, and the like. Among them, the addition reaction type polysiloxane resin has the advantages of "high reactivity and good productivity, and when compared with the condensation reaction type, the change in the peeling force after manufacture is small, and there is no hardening shrinkage" and other advantages, so is better.

Specific examples of the above-mentioned addition reaction type polysiloxane resins include those having 2 to 10 carbon atoms such as vinyl groups, allyl groups, propenyl groups, hexenyl groups, etc., at the terminal and/or side chain of the molecule, for example. Alkenyl-based organopolysiloxanes, etc. When such an addition reaction type polysiloxane resin is used, it is preferable to use a crosslinking agent and a catalyst together.

The above-mentioned crosslinking agent includes, for example, an organopolysiloxane having at least two hydrogen atoms bonded to a silicon atom in one molecule, and specifically, for example, a dimethylhydrosiloxy terminal-blocked dimethyl Siloxane-methylhydrosiloxane copolymer, trimethylsiloxy-terminated dimethylsiloxane-methylhydrosiloxane copolymer, trimethylsiloxy-terminated methylhydrogen Polysiloxane, poly(hydrosilsesquioxane), etc.

The above catalysts include, for example, particulate platinum, particulate platinum adsorbed on carbon powder carriers, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, rhodium and other platinum metal compounds, etc. By using such a catalyst, the hardening reaction of the composition for forming a peeling layer can be performed more efficiently.

When a silicone resin is used in the composition for forming a peeling layer, it is preferable to add a peeling modifier such as MQ resin.

Moreover, in the composition for peeling layer formation, you may mix|blend suitably the additive Additives. The additives include, for example, catalysts, dyes, dispersants, and the like. In addition, in order to make the viscosity at the time of application|coating into an appropriate range in the composition for peeling layer formation, you may contain a dispersion medium or a solvent suitably.

Examples of the dispersion medium or solvent include aromatic hydrocarbons 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 separation film (C) can be produced by, for example, applying the composition for forming a release layer diluted in a solvent to one side of a plastic film by the following method. For example, a gravure coating method, a bar coating method, a spray coating method, a spin coating method, an air knife coating method, a roll coating method, a blade coating method, a gate roll coating method, and a die coating method can be mentioned. coating method, etc. Among these, a gravure coating method and a bar coating method are preferable, and a gravure coating method is more preferable.

Moreover, the heating and drying method of the composition for peeling layer formation is mentioned, for example, the method of heat-drying by a hot air drying furnace etc. is mentioned. The drying temperature is, for example, 50°C or higher and 150°C or lower. Also, the drying time is, for example, preferably 10 seconds to 5 minutes.

The film thickness of the separation film (C) can be controlled by the thickness of the plastic film and the thickness of the peeling layer. Among them, the thickness of the plastic film is the main one, which can be controlled by selecting a polyester film with a target thickness. The thickness of the plastic film is preferably 45 μm or more, more preferably 47 μm or more, and still more preferably 50 μm or more. Although the upper limit of the film thickness of the plastic film is not particularly limited, it is usually 200 μm or less. From the viewpoint of facilitating peeling when peeling the separation film, for example, it is preferably 150 μm or less, more preferably 100 μm or less. The thickness (dry) of the peeling layer is preferably 40 to 300 nm, more preferably 50 to 200 nm, Still more preferably, it is 80 to 150 nm. By making the thickness of the peeling layer 40 nm or more, unevenness of the peeling force due to variation in the coating amount can be suppressed, and by making it 300 nm or less, blocking can be suppressed.

In the present invention, the peeling force of the separation membrane (C) with respect to the adhesive layer (B) may be, for example, 0.01 to 0.10 N/25 mm, preferably 0.02 to 0.08 N/25 mm. When the peeling force of the separation film (C) is within the above-mentioned range, the creep force at the interface with the adhesive layer (B) becomes high, and the effect of suppressing the occurrence and progression of striae wrinkles when the optical film is cut into small pieces can be improved. . The peeling force of the separation film can be controlled, for example, by the polarity and elastic modulus of the surface of the peeling layer. Specifically, for example, polysiloxane or silicon oxide can be added to the peeling layer forming composition as a heavy peeling regulator. , or add polysiloxane oil or the like to the peeling layer forming composition as a light peeling regulator to control. Furthermore, the aforementioned peeling force is based on JIS-Z0237, cutting the optical film with the adhesive layer of the laminated separation film into a width of 25 mm and a length of 200 mm, and using a tensile tester to test the adhesion of the laminated separation film. The measurement was performed by stretching the separation film in the direction of 180° at a speed of 300 mm/min in a state where the optical film of the agent layer was fixed.

Moreover, the elastic modulus of the peeling layer of the separation membrane (C) may be, for example, 0.3 to 15.0 MPa, or preferably 0.5 to 7.0 MPa. When the elastic modulus of the peeling layer of the separation film (C) is within the above-mentioned range, the creep force at the interface between the separation film (C) and the adhesive layer (B) becomes high, which can improve the elasticity when cutting the optical film into small pieces. The effect of suppressing the occurrence and progression of striae wrinkles. The elastic modulus of the peeling layer can be added by, for example, increasing the amount of vinyl groups used in the polysiloxane resin, or adding polysiloxane resin or silicon oxide to the composition for forming the peeling layer. agent to control. In addition, the said elastic modulus can be measured by DMA (23 degreeC) using the polysiloxane block produced by casting (cast) the peeling layer forming composition.

[4] Composition and manufacturing method of an optical film with an adhesive layer through a laminated separation film

For example, as shown in FIG. 1, the optical film 1 having the adhesive layer of the separation film laminated includes the optical film 10 and the adhesive layer 20 laminated on at least one side of the optical film 10, and the adhesive layer 20 The outer surface area of the separation membrane 30 is layered. The adhesive layer 20 is layered on a single area of the optical film 10 . When laminating the adhesive layer 20 on the surface of the optical film 10, it is preferable to form a primer layer on the bonding surface of the optical film 10 and/or the bonding surface of the adhesive layer 20, or perform surface activation treatment (for example, Plasma treatment, corona treatment, etc.), particularly preferably corona treatment.

Between the optical film 10 and the adhesive layer 20, an antistatic layer may be additionally disposed. For the antistatic layer, silicon-based materials such as polysiloxane can be used; inorganic metal-based materials such as tin-doped indium oxide and tin-doped antimony oxide; polythiophene, polystyrene sulfonic acid, polyaniline, etc. Organic polymer materials.

The optical film 1 to which the adhesive layer of the separation film is laminated can be obtained, for example, by the following process: Dissolving or dispersing each component of the adhesive composition forming the adhesive layer (B) in a solvent to prepare a composition containing A solvent-based adhesive composition is then applied to the release-treated surface of the separation film 30, dried to form an adhesive layer 20, and the adhesive layer 20 is laminated (transferred) on the surface of the optical film 10. .

[Example]

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these examples. Hereinafter, the parts and % indicating the usage amount and content are based on the quality unless otherwise specified.

1. Separation membrane

(1) Production of separation membrane

(i-1) Preparation of the composition (a) for forming a peeling layer

Organopolysiloxane with vinyl group, organopolysiloxane with hydrosilyl group, and polysiloxane resin solution containing heavy release additive (Toray Dow Corning Corporation, trade name: BY24-571, solid Part 30 mass %) was converted into 30 mass parts in solid content, diluted and mixed with the solvent of toluene/MEK=1/1, and made the solid content concentration 1.0 mass %. To this solution, 2 parts by mass of a platinum-based catalyst (manufactured by Toray Dow Corning, trade name: SRX-212, solid content 100% by mass) was added to prepare a composition (a) for forming a peeling layer.

(i-2) Preparation of the release layer forming composition (b)

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

(ii) Production of Separation Membrane 1

Prepare a biaxial extension with a thickness of 50 μm, an end azimuth angle of 8 degrees, and a haze of 3%. Stretched polyethylene terephthalate (PET) film A (PET50T-193 manufactured by Mitsubishi Plastics Corporation). Next, on one side of the biaxially stretched PET film A, the above-obtained composition (a) for forming a release layer was applied with a bar coater to a thickness of 0.1 μm after drying, and dried at 120° C. for 1 minute to form a release layer. layer to obtain separation membrane 1. The bending stiffness of the separation membrane 1 measured by the method described later was 1.73 mg.

(iii) Fabrication of Separation Membrane 2

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

(iv) Production of separation membrane 3

A biaxially stretched polyethylene terephthalate (PET) film A (PET50T-193 manufactured by Mitsubishi Plastics Corporation) having a thickness of 50 μm, an end azimuth angle of 8 degrees, and a haze of 3% was prepared. Then, on one side of the biaxially stretched PET film A, the above-obtained composition (b) for forming a release layer was applied with a bar coater so that the thickness after drying was 0.1 μm, and dried at 120° C. for 1 minute to form a The layer was peeled off to obtain a separation membrane 3 . The bending stiffness of the separation membrane 3 measured by the method described later was equivalent to that of the separation membrane 1 (about 1.73 mg).

(v) Preparation of separation membrane 4

Prepare two axes with a thickness of 38 μm, an end azimuth angle of 6 degrees, and a haze of 10% Stretched polyethylene terephthalate (PET) film B (PET38R-64 manufactured by Toray Corporation). Then, on one side of the biaxially stretched PET film B, the above-obtained release layer forming composition (b) was applied with a bar coater so that the thickness after drying was 0.1 μm, and dried at 120° C. for 1 minute to form a release layer. layer to obtain separation membrane 4 . The bending stiffness of the separation membrane 4 measured by the method described later was equivalent to that of the separation membrane 2 (about 0.53 mg).

(2) Measurement of physical properties of separation membrane

(i) Bending stiffness

<Measurement preparation>

The separation membranes 1 to 4 prepared above were cut into test pieces of 25.4 mm × 25.4 mm, respectively, and then one end of the test pieces was mounted on a Gurley type tester (Gurley stiffness tester (electric type) 2094- M: A collet for a movable arm of Kumagai Riki Co., Ltd.). Align the 1-inch (25.4mm) scale on the movable arm A and fix the chuck, so that the test piece is moved to the position away from the apex of the pendulum B first. Then, a 5g weighing weight is installed at the position of the load mounting hole a (1 inch) below the fulcrum of the pendulum B, so that it is in a vertical state without vibration.

<Measurement operation>

Move the movable arm to the right or left at a constant speed 2 times/min. The lower part of the test piece was in contact with the pendulum B, and the scale R when it moved away from the pendulum B was read, and the bending stiffness was calculated by applying the following conversion formula.

S=((aWa+bWb+cWc)/5)×(l ² /b)×11.1×R (mg)

S: Bending stiffness (mg)

a,b,c: Distance between the load mounting hole and the fulcrum of the pendulum (inches)

Wa,Wb,Wc: The mass of the weighing scale installed in the load mounting hole

l: Full length of test piece - 1/2" (inch)

b: Width of the test piece (inches)

R: the reading of the scale

2. Production of optical film and optical film with adhesive layer attached to the laminated separation film

(1) Preparation of (meth)acrylic resin for adhesive layer

In a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dripping device, and a nitrogen gas introduction pipe, 87.5 parts by mass of n-butyl acrylate, 5 parts by mass of methyl acrylate, 5 parts by mass of 2-phenylethyl acrylate, 2.5 parts by mass of 2-hydroxyethyl acrylate, 200 parts by mass of ethyl acetate, and 0.08 part by mass of 2,2'-azobisisobutyronitrile, and the air in the reaction container was replaced with nitrogen gas. The reaction solution was heated to 60° C. with stirring in this nitrogen atmosphere, and allowed to react for 16 hours, and then cooled to room temperature. Here, the molecular weight of a part of the obtained solution was measured by the method mentioned later, and it was confirmed that a (meth)acrylate polymer having a weight average molecular weight of 2 million was produced.

The weight-average molecular weight (Mw) of the above-mentioned (meth)acrylate polymer is the weight-average molecular weight in terms of polystyrene measured under the following conditions using a gel permeation chromatography (GPC).

[Measurement conditions]

‧GPC measurement device: HLC-8020 manufactured by Tosoh Corporation

‧GPC column (through the following sequence): manufactured by Tosoh Corporation

TSK guard column HXL-H

TSK gel GMHXL (x2)

TSk gel G2000HXL

‧Measurement solvent: tetrahydrofuran

‧Measurement temperature: 40℃

(2) Production of adhesive layer

(a) Preparation of adhesive composition

100 parts by mass of the (meth)acrylate polymer (meth)acrylate polymer obtained in the above step (1) (converted value of solid content; the same below), as the isocyanate-based crosslinking agent (B), the trimethylolpropane-modified ethylene glycol 0.20 parts by mass of tolyl diisocyanate (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name "TAKENATE D-110N"), 3-mercaptopropyltrimethoxysilane and methyltriethoxysilane as silane coupling agents (C) 0.30 parts by mass of the co-condensate (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X41-1810") was mixed, stirred well, and diluted with ethyl acetate to obtain a coating solution of the adhesive composition.

(b1) Production of adhesive layer 1 (adhesive sheet 1)

The adhesive composition prepared in the above (a) was applied with an applicator so that the thickness after drying might be 20 μm on the release-treated surface (peeling layer) of the separation membrane 1 obtained above, and then dried at 100° C. In 1 minute, the adhesive layer 1 was obtained as the adhesive sheet 1 .

(b2) Production of adhesive layer 2 (adhesive sheet 2)

The adhesive layer 2 was obtained as the adhesive sheet 2 in the same manner as in the production of the adhesive layer 1 except that the separation membrane 2 obtained above was used instead of the separation membrane 1 .

(b3) Production of adhesive layer 3 (adhesive sheet 3)

The adhesive layer 3 was obtained in the same manner as in the production of the adhesive layer 1 except that the separation membrane 3 obtained above was used in place of the separation membrane 1, as Adhesive Sheet 3.

(b4) Production of adhesive layer 4 (adhesive sheet 4)

The adhesive layer 4 was obtained as the adhesive sheet 4 in the same manner as in the production of the adhesive layer 1 except that the separation membrane 4 obtained above was used instead of the separation membrane 1 .

(3) Production of an optical film with an adhesive layer of a laminated separation film

(I) Example 1: Optical Film A with Adhesive Layer of Laminated Separation Membrane

(i) Modulation of polarizing film (polarizer) A

A polyvinyl alcohol film ("Kuraray Poval Film VF-PE#3000", manufactured by Kuraray Co., Ltd.) having an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol%, and a thickness of 30 μm was immersed in pure water at 37°C Then, it was immersed in the aqueous solution (iodine/potassium iodide/water (weight ratio)=0.04/1.5/100) containing iodine and potassium iodide at 30 degreeC. Then, it was immersed in the aqueous solution (potassium iodide/boric acid/water (weight ratio)=12/3.6/100) containing potassium iodide and boric acid at 56.5 degreeC. 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 aligned to polyvinyl alcohol. The extension was mainly carried out in the steps of iodine dyeing and boric acid treatment, and the total extension magnification was 5.3 times.

(ii) Modulation of Optical Film A

On one side of the obtained polarizing film, a transparent protective film (" 25KCHCN-TC", manufactured by Toppan Printing Co., Ltd.), and a 23-μm-thick cyclic olefin-based film is attached to the opposite side of the transparent protective film. Resin film ("ZF14-023", manufactured by Japan ZEON Co., Ltd.), and optical film A (polarizing plate, thickness 67 μm) was produced.

The water absorption 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 rate)

After the optical film was cut into a size of 80mm×80mm, the cut test pieces were used as an aggregate, and they were put into a constant temperature and humidity tank with a temperature of 23°C and a relative humidity of 90%RH. The tank was taken out, and the total weight (W _A ) of the five test pieces was measured. Then, the five measurement test pieces after the weight measurement were put into an oven in a dry environment at a temperature of 95°C, taken out from the oven 2 hours later, and the total weight (W _B ) of the five test pieces was measured. From W _A and W _B , the water absorption rate was calculated|required by the following formula.

Water absorption rate=(W _A -W _B )/W _B ×100(%)

(iii) Optical film with adhesive layer of lamination separation film

Production of (polarizing plate)

The surface (adhesive layer layer) of the adhesive sheet 1 produced in the above (b1) on the opposite side to the separation membrane was bonded to the surface of the obtained optical film A to which the cyclic olefin-based resin film was bonded by a laminator. After that, it was aged for 7 days under the conditions of a temperature of 23° C. and a relative humidity of 65% to obtain the adhesive layer of the optical film A (polarizing plate) by laminating the adhesive layer and the separation film 1 in sequence on one side. The optical film A1 (polarizing plate) of the agent layer.

Comparative Example 1

Except using the adhesive sheet 2 obtained in the above (b2) instead of the adhesive sheet 1, the same procedure as in Example 1 was carried out to obtain the optical film A (polarized light). The optical film A2 (polarizing plate) in which the pressure-sensitive adhesive layer and the separation film 2 are sequentially laminated on one side of the plate) and the pressure-sensitive adhesive layer of the separation film is laminated.

Comparative Example 2

In the same manner as in Example 1, except that the adhesive sheet 3 obtained in the above (b3) was used instead of the adhesive sheet 1, the adhesive layer and the separation film 3 were sequentially laminated on one side of the optical film A (polarizing plate). The optical film A3 (polarizing plate) composed of the adhesive layer of the laminated separation film.

Comparative Example 3

In the same manner as in Example 1, except that the adhesive sheet 4 obtained in the above (b4) was used instead of the adhesive sheet 1, the adhesive layer and the separation film 4 were sequentially laminated on one side of the optical film A (polarizing plate). The optical film A4 (polarizing plate) composed of the adhesive layer of the laminated separation film.

(4) Creep force at the interface between the separation membrane and the adhesive layer

After the optical films A1 to A4 with the adhesive layer of the laminated separation film produced above were cut into a size of 110 mm × 15 mm, respectively, according to FIG. The separation film was cut at mm, and the optical film with the adhesive layer was cut at 7.5 mm from the center portion of the cut sample to the right side surface side and from the protective film side. One end of the long side of the test piece was attached to the upper chuck of a tensile tester (Autograph AG-1S MO (landscape) type, manufactured by Shimadzu Corporation) so that the test piece was vertical. Then, the end on the opposite side of the upper chuck mounting side was attached to the lower chuck, and the lower chuck was moved downward at a moving speed of 1 mm/min until the moving distance became 5 mm, and the required movement during this period was measured. The maximum value of the force, as the creep force. The results are shown in Table 1.

3. Appearance evaluation of the optical film with the adhesive layer of the laminated separation film

The appearance of the optical film with the adhesive layer was evaluated according to the following method.

The above-produced optical films A1 to A4 with the adhesive layer of the laminated separation film were cut by a continuous automatic cutting machine "super cutter" (model PN1-600) (press-cut type) manufactured by Ogino Seiki Seiki Co., Ltd. The size of 60mm × 100mm was used as a test piece, and after 144 hours (1 week), it was put into a high temperature and high humidity tank with a temperature of 23°C and a humidity of 65%RH. While irradiated with fluorescent light, the test piece was visually inspected with reflected light from a distance of about 300 mm to 500 mm, and it was confirmed whether or not minute streak-like wrinkles were generated. The results are shown in Table 1.

Appearance Evaluation Criteria

×: It was confirmed that streak-like wrinkles having a length of about 1 mm to 30 mm, a width of about 0.5 mm to 2 mm, and a depth of about 0.1 μm to 1 μm were generated.

(circle) : The generation|occurrence|production of the said streak-like wrinkles was not recognized.

The film thickness of the separation membrane is 45 μm or more and the creep force of the interface between the separation membrane and the adhesive layer is 3N or more. The optical film of Example 1 with the adhesive layer of the laminated separation membrane does not produce extremely small streaks. No appearance defect. On the other hand, the optical film of Comparative Example 1 with the adhesive layer of the separation film laminated in the film thickness of the separation film was less than 45 μm, even if the creep force was 3N or more, streak-like wrinkles occurred, resulting in poor appearance. Moreover, even if the film thickness of the separation film was 45 μm or more, the optical film of Comparative Example 2 with a creep force of less than 3N and the adhesive layer of the laminated separation film had a streak-like wrinkle, resulting in poor appearance. In addition, the optical film of Comparative Example 3 with the film thickness of the separation film less than 45 μm and the creep force of less than 3N having the adhesive layer of the laminated separation film had a streak-like wrinkle and a poor appearance.

Since the figure in this case also includes the content that is not defined in the invention claimed in the scope of the patent application in this case, and is not a representative figure in this case, there is no designated representative figure in this case.

Claims (5)

An optical film to which an adhesive layer of a separation film is laminated, comprising: a separation film (C) laminated via an adhesive layer (B) on at least one side of the optical film (A); wherein the separation film (C) It is composed of a plastic film and a peeling layer; the peeling layer is formed from a composition for forming a peeling layer containing a polysiloxane resin; so that the elastic modulus of the peeling layer is 0.3 to 15.0 MPa and the separation film (C) For the peeling force of the adhesive layer (B) of 0.01 to 0.10 N/25mm, polysiloxane or silicon oxide is added to the peeling layer forming composition as a heavy peeling adjuster; the film of the aforementioned separation film (C) The thickness is 45 μm or more, and the creep force at the interface of 15 mm×15 mm between the separation membrane (C) and the adhesive layer (B) is 3N or more and 15N or less. The optical film to which the adhesive layer of the separation membrane is laminated according to claim 1, wherein the separation membrane (C) has a bending stiffness of 1 mg or more. The optical film with the adhesive layer of the laminated separation membrane as described in claim 1 or 2, wherein the optical film (A) has a water absorption rate of 2.0% or more. The optical film with the adhesive layer of the laminated separation film as described in claim 1 or 2, wherein the optical film (A) has a film thickness of 100 μm or less. The film thickness of the said optical film (A) is 100 micrometers or less, The optical film by which the adhesive bond layer of a laminated separation film was laminated|stacked as described in Claim 3.

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