CN107589481A - Band is laminated with the optical film of the adhesive phase of barrier film - Google Patents

Abstract

An optical film with an adhesive layer laminated with a separator. An object of the present invention is to provide an optical film with a pressure-sensitive adhesive layer which exhibits less sagging under pressure and is particularly effective in preventing damage or dents caused by foreign matter during storage, transportation, and handling. An optical film with an adhesive layer laminated with a separator, comprising a separator laminated via an adhesive layer (B) on at least one side of the optical film (A), wherein the film thickness of the separator (C) is 45 μm As mentioned above, the film thickness of the said optical film (A) is 100 micrometers or less.

Description

Optical film with adhesive layer laminated with separator

technical field

The present invention relates to an optical film having an adhesive layer laminated with a separator.

Background technique

An optical film represented by a polarizing plate obtained by laminating a transparent resin film on one or both sides of a polarizing plate is widely used as an optical member constituting an image display device such as a liquid crystal display device. An optical film such as a polarizing plate or a phase difference plate is often constituted as an optical film with an adhesive layer provided on one side thereof, and is often bonded to a liquid crystal through the adhesive layer. Cells, organic EL display elements and other display elements. In order to protect the pressure-sensitive adhesive layer before bonding to the display element, a separator that is peeled and removed during use of the pressure-sensitive adhesive layer is usually laminated on such an optical film with a pressure-sensitive adhesive layer (Patent Document 1).

prior art literature

patent documents

Patent Document 1: International Publication No. 2009/069799

Contents of the invention

The problem to be solved by the invention

In recent years, there is a tendency for image display devices to be thinner, and therefore, thinner optical films such as 100 μm or less are desired as optical films. An adhesive layer is provided on such a thin optical film and a separator is laminated on the adhesive layer (an optical film with an adhesive layer laminated with a separator) is often wound into a Storage, transport or handling in roll form. At this time, if the optical film on which the adhesive layer of the separator is laminated is wound up in a state in which foreign matter such as dust adheres to the outer surface of the separator, it will be damaged during storage, transportation, and handling due to the pressure of the wound films. Pressing foreign matter to the optical film will leave damage or scratches caused by the foreign matter on the optical film even after depressurization. In addition, an optical film with an adhesive layer laminated with a separator may be cut into a size corresponding to the size of a display element to which the optical film is to be bonded, and stored and transported after stacking. Even in this case, if a foreign substance is present between the overlapping optical films with the separator-laminated pressure-sensitive adhesive layer, damage or scratches due to the foreign substance will remain on the optical film. Such damage or scratches caused by foreign matter will cause defects in the optical properties of the optical film. Therefore, an adhesive film laminated with a separator that is highly effective in preventing damage or scratches to the optical film caused by foreign matter is required. Mixture layer of optical film.

Therefore, the object of the present invention is to provide an adhesive layer with a separator laminated thereon, which has less dent under pressure and is excellent in preventing damage or dents caused by foreign matter during storage, transportation, and handling. optical film.

means to solve the problem

The inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and as a result, completed the present invention.

That is, the present invention includes the following preferred aspects [1] to [3].

[1] An optical film with an adhesive layer laminated with a separator, comprising a separator (C) laminated via an adhesive layer (B) on at least one side of the optical film (A),

The film thickness of the said separator (C) is 45 micrometers or more, and the film thickness of the said optical film (A) is 100 micrometers or less.

[2] The optical film with an adhesive layer laminated with a separator according to [1] above, wherein the separator (C) has a Vickers hardness of 15 or more on its surface.

[3] The optical film having an adhesive layer laminated with a separator according to the above [1] or [2], wherein the separator (C) has a bending stiffness of 1 mg or more.

[4] The optical film with an adhesive layer laminated with a separator according to any one of the above [1] to [3], wherein the storage elastic modulus at 25° C. of the adhesive layer (B) is G' is 0.4 MPa or less.

Invention effect

According to the present invention, it is possible to provide an optical film with an adhesive layer laminated with a separator, which exhibits less sag under pressure and is excellent in preventing damage or dents caused by foreign matter during storage, transportation, and handling.

Description of drawings

FIG. 1 is a schematic cross-sectional view showing an example of an optical film having a separator-laminated pressure-sensitive adhesive layer of the present invention.

Fig. 2 is a schematic cross-sectional view showing an example of an optical film having a separator-laminated pressure-sensitive adhesive layer of the present invention.

detailed description

<Optical film with adhesive layer laminated with separator>

The optical film with a separator-laminated adhesive layer of the present invention includes an optical film (A) and a separator (C) laminated on at least one surface of the optical film (A) via an adhesive layer (B).

In the optical film with the pressure-sensitive adhesive layer laminated with the separator of the present invention, the film thickness of the separator (C) is 45 μm or more. If the film thickness of the separator is less than 45 μm, dents caused by foreign matter adhering to the surface of the separator tend to reach the adhesive layer, making it difficult to sufficiently ensure the effect of preventing damage or scratches on the optical film. In the optical film with a separator-laminated pressure-sensitive adhesive layer of the present invention, the film thickness of the separator (C) is preferably 45 μm or more, more preferably 47 μm or more, still more preferably 50 μm or more. The upper limit of the film thickness of the separator (C) is not particularly limited, but is usually 200 μm or less, and is preferably 150 μm or less, more preferably 100 μm or less, since the separator is easily pulled up when the separator is peeled off.

In the optical film with the pressure-sensitive adhesive layer laminated with the separator of the present invention, the film thickness of the optical film (A) is 100 μm or less. In the optical film with a separator-laminated pressure-sensitive adhesive layer of the present invention, the film thickness of the optical film (A) is preferably 80 μm or less, more preferably 70 μm or less. The lower limit of the film thickness of the optical film (A) is usually 5 μm or more, for example, preferably 10 μm or more, more preferably 15 μm or more, from the viewpoint of easy handling.

Here, in the present invention, the optical film is a film that functions for image display (display screen, etc.) (for example, a film that functions for improving the visibility of images), and it means Films with various optical properties of image display devices, such as single-layer structures (such as polarizers, retardation films, brightness enhancement films, anti-glare films, anti-reflection films, diffusion films, light-concentrating films, etc.) film, etc.), or a multilayer structure (such as a polarizing plate, a retardation plate, etc.).

In the present invention, the "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. Refers to the total thickness of all the layers making up the multilayer structure. It should be noted that 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 is not considered to constitute the optical film (A) The layers are not considered when calculating the film thickness of the optical film (A). Therefore, for example, in the optical film with the pressure-sensitive adhesive layer laminated with the separator of the present invention shown in FIG. total thickness. Moreover, in the optical film with the adhesive layer laminated|stacked with the separator of this invention shown in FIG. The total thickness of the hard coat 6.

In the present invention, the thicker the film thickness of the separator (C), the higher the effect of preventing damage or dents caused by foreign matter, etc., is. The film thickness is balanced, so that the effect of preventing optical film damage or scratches caused by foreign matter can be more effectively improved. For example, the ratio (T _C / _TA ) of the thickness t _C of the separator to the thickness t _A of the optical film is, for example, preferably 0.4 or more, more preferably 0.5 or more, and still more preferably 0.6 or more. This ratio (T _C /T _A ) is usually 4 or less.

The optical film with an adhesive layer laminated with a separator according to the present invention is as long as it includes an optical film (A) and a separator (C) laminated on at least one side of the optical film (A) via an adhesive layer (B). ) and have the optical film generally have the function that the optical film has, the structure is not limited. As the optical film, a polarizing plate, a polarizing plate, a retardation plate, or a retardation film is preferable, and a polarizing plate or a polarizing plate is particularly preferable.

For example, if the configuration of a suitable embodiment of the present invention is described based on FIGS. 1 and 2 , the optical film 1 shown in FIG. The separator 30 is laminated via the adhesive layer 20 on one side. Furthermore, in the optical film 10, resin films 3 and 4 are laminated on both sides of the polarizer 2, and a protective film is laminated on the surface of the resin film 4 on the opposite side to the resin film having the adhesive layer 20 that does not contact the polarizer 2. 5. In addition, the optical film 1 shown in FIG. 2 with an adhesive layer laminated with a separator is composed of an optical film 10 and a separator 30 laminated via an adhesive layer 20 on one side of the optical film, and the optical film 10 is polarized. Resin films 3 and 4 are laminated on both sides of the sheet 2 , and a hard coat layer 6 is provided on the surface of the resin film 4 on the opposite side to the resin film having the adhesive layer 20 that does not contact the polarizing plate 2 . Furthermore, a protective film 5 is laminated on the hard coat layer 6 . In addition, the resin films 3 and 4 can be bonded to the polarizing plate 2 via the adhesive layer or adhesive layer which are not shown in figure.

Each layer (member) constituting the optical film with a separator-laminated pressure-sensitive adhesive layer of the present invention is not particularly limited, and may be appropriately determined according to desired properties of the optical film. Hereinafter, about each constituent component of the optical film with the pressure-sensitive adhesive layer laminated|stacked with the separator of this invention, the suitable aspect is demonstrated in detail.

[1] Optical film (A)

[1-1] Polarizing plate

In this specification, a polarizing plate refers to a member in which a resin film or a resin layer is laminated on at least one surface of a polarizing plate. The polarizer is a film that absorbs linearly polarized light having a vibration plane parallel to its absorption axis and transmits linearly polarized light having a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). A film in which a dichroic dye is adsorbed and oriented on a vinyl alcohol-based resin film. As a dichroic dye, iodine, a dichroic organic dye, etc. are mentioned, for example.

The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. Examples of polyvinyl acetate-based resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and monomers that can be copolymerized with vinyl acetate (such as unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, etc.) acid, (meth)acrylamide having an ammonium group, etc.) and a copolymer of vinyl acetate, etc.

The saponification degree of polyvinyl alcohol-type resin is 85-100 mol% normally, Preferably it is 98 mol% or more. The polyvinyl alcohol-based resin may be modified, for example, it may be polyvinyl formal or polyvinyl acetal modified with aldehydes. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000. In addition, the average degree of polymerization of a polyvinyl-alcohol-type resin can be calculated|required according to JISK6726.

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

The polarizing plate is produced by, for example, a step of uniaxially stretching a raw film, a step of dyeing the film with a dichroic dye to adsorb the dichroic dye, a step of treating the film with a boric acid aqueous solution, and A process of washing the film with water and finally drying it. In the present invention, the thickness of the polarizing plate is usually 1 to 50 μm, preferably 30 μm or less, more preferably 15 μm or less, particularly preferably 10 μm or less from the viewpoint of thinning the optical film.

A polarizing plate in which a polyvinyl alcohol-based resin film is adsorbed and oriented with a dichroic dye can also be obtained by the following method: 1) Using a single film of a polyvinyl alcohol-based resin film as a raw material film, and subjecting the film to uniaxial The method of stretching treatment and dyeing treatment of dichroic dye; and 2) coating liquid (aqueous solution, etc.) A method of uniaxially stretching the base film together with the base film, dyeing the stretched polyvinyl alcohol-based resin layer with a dichroic dye, and then peeling off the base film. As the base film, a film containing the same thermoplastic resin as the thermoplastic resin that can constitute the resin film described later can be used. Polyester-based resins such as polyethylene terephthalate, polycarbonate-based resins, cellulose-based resins such as triacetyl cellulose, cyclic polyolefin-based resins such as norbornene-based resins, polyphenylene resins, etc. Films such as vinyl resins. According to the above-mentioned method 2), it is easy to produce a thin-film polarizing plate, and it is also easy to produce a polarizing plate having a thickness of, for example, 7 μm or less.

The resin film may be made of a thermoplastic resin having light transmission, preferably optical transparency, such as chain polyolefin resins (polyethylene resins, polypropylene resins, etc.), cyclic polyolefin resins (norbornene resins, etc.), ) and other polyolefin-based resins; cellulose-based resins (cellulose ester-based resins, etc.); polyester-based resins (polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate Glycol esters, etc.); polycarbonate-based resins (such as polycarbonates derived from bisphenols such as 2,2-bis(4-hydroxyphenyl)propane); (meth)acrylic resins; polystyrene-based resins Resin; polyether ether ketone resin; polysulfone resin, or a film of their mixture, copolymer, or the like. Among them, the resin film is preferably a film made of cyclic polyolefin-based resin, polycarbonate-based resin, cellulose-based resin, polyester-based resin, and (meth)acrylic resin, and is particularly preferably made of cellulose-based resin. and films made of cyclic polyolefin-based resins, etc.

Examples of chain polyolefin-based resins include homopolymers of chain olefins such as polyethylene resins and polypropylene resins; copolymers containing two or more chain olefins; and the like.

The cyclic polyolefin-based resin is a general term for resins including cyclic olefins typified by norbornene, tetracyclododecene (another name: dimethyloctahydronaphthalene) or derivatives thereof as polymerized units. Examples of cyclic polyolefin-based resins include ring-opening (copolymerization) polymers of cyclic olefins and their hydrogenated products; addition polymers of cyclic olefins; chain olefins such as cyclic olefins and ethylene, propylene, or Copolymers of aromatic compounds based on bases; and modified (copolymerized) polymers modified with unsaturated carboxylic acids or their derivatives, etc. Among them, norbornene-based resins using norbornene-based monomers such as norbornene and polycyclic norbornene-based monomers as cyclic olefins are preferable.

The cellulose-based resin is preferably a cellulose ester-based resin, that is, a partially or completely esterified product of cellulose, and examples thereof include cellulose acetate, propionate, butyrate, and mixed esters thereof. Among them, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like are preferable.

The polyester-based resin is a resin other than the aforementioned cellulose ester-based resins having an ester bond, and is usually a resin formed of a polycondensate of a polycarboxylic acid or a derivative thereof and a polyhydric alcohol. Examples of polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate, Trimethylene phthalate, polytrimethylene naphthalate, polycyclohexanedimethylene terephthalate, polycyclohexanedimethylene naphthalate, and the like.

Polycarbonate-based resins are polyesters composed of carbonic acid and diols or bisphenols. Among these, aromatic polycarbonates having diphenylalkane in their molecular chains are preferable from the viewpoint of heat resistance, weather resistance, and acid resistance. Examples of polycarbonates include 2,2-bis(4-hydroxyphenyl)propane (alias: bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1- Bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane, 1,1-bis(4-hydroxyphenyl)ethane and other bisphenol-derived polycarbonates Wait.

The (meth)acrylic resin that can constitute the resin film can be a polymer mainly composed of a structural unit derived from methacrylate (for example, containing 50% by weight or more of the structural unit), and it is preferable that the structural unit is copolymerized with other A copolymer formed by copolymerization of components. The (meth)acrylic resin may contain two or more kinds of structural units derived from methacrylate esters. Examples of the methacrylate include C ₁ -C ₄ alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

Acrylic ester is mentioned as a copolymerization component which can be copolymerized with methacrylate. The acrylate is preferably a C ₁ -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 acids such as (meth)acrylic acid; aromatic vinyl compounds such as styrene, halogenated styrene, α-methylstyrene, and vinyl toluene; (methyl) ) vinyl cyanide compounds such as acrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; Compounds other than acrylates with permanent carbon-carbon double bonds. A compound having two or more polymerizable carbon-carbon double bonds in the molecule can also be used as a copolymerization component. A copolymerization component can be used individually or in combination of 2 or more types.

The (meth)acrylic resin may have a ring structure in the polymer main chain 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, and a lactone ring structure. Specific examples of the cyclic acid anhydride structure include a glutaric anhydride structure and a succinic anhydride structure, and specific examples of the cyclic imide structure include a glutarimide structure and a succinimide structure. etc. Specific examples of the lactone ring structure include a butyrolactone ring structure, a valerolactone ring structure, and the like.

The (meth)acrylic resin may contain acrylic rubber particles from the viewpoints of film forming property of a film, impact resistance of a film, and the like. The acrylic rubber particle refers to a particle containing an elastic polymer mainly composed of acrylate as an essential component, and examples include acrylic rubber particles having a single-layer structure substantially composed only of the elastic polymer. Layers of acrylic rubber particles in a multilayer structure. Examples of the elastic polymer include a crosslinked elastic copolymer obtained by copolymerizing an alkyl acrylate as a main component and other vinyl monomers and crosslinkable monomers that can be copolymerized therewith. Examples of the alkyl acrylate used as the main component of the elastic polymer include C ₁ -C ₈ alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The carbon number of the alkyl group is preferably 4 or more.

Examples of other vinyl monomers that can be copolymerized with alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, more specifically, methyl methacrylate and the like. Aromatic vinyl compounds such as methacrylate and styrene, vinyl cyanide compounds such as (meth)acrylonitrile, and the like. Examples of the crosslinkable monomer include crosslinkable compounds having at least two polymerizable carbon-carbon double bonds in the molecule, more specifically, ethylene glycol di(meth)acrylate, butyl Polyol (meth)acrylates such as diol di(meth)acrylate; alkenyl (meth)acrylates such as allyl (meth)acrylate; divinylbenzene, etc.

The content of the acrylic rubber particles is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, based on 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 decreases. Therefore, the content of the acrylic rubber particles is usually 80 parts by mass or less, preferably 60 parts by mass or less, based on 100 parts by mass of the (meth)acrylic resin.

Common additives in the technical field of the present invention may be contained in the resin film. Examples of additives include ultraviolet absorbers, infrared absorbers, organic dyes, pigments, inorganic colorants, antioxidants, antistatic agents, surfactants, lubricants, dispersants, heat stabilizers and the like. Examples of the ultraviolet absorber include salicylate compounds, benzophenone compounds, benzotriazole compounds, triazine compounds, cyano(meth)acrylate compounds, nickel complex salts, and the like.

The resin film may be either an unstretched film or a uniaxially stretched or biaxially stretched film. The resin film may be a protective film serving to protect the polarizer, or may be a protective film having an optical function such as a retardation film described later. In addition, when a polarizing plate contains several types of resin films, these resin films may be the same or different films.

In addition, the resin film may be provided with a surface treatment layer such as a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, an antistatic layer, an antifouling layer, and a conductive layer on the outer surface (the surface opposite to the polarizer). (coating). 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 bonded to a polarizing plate 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 containing aqueous solutions of polyvinyl alcohol-based resins, water-based two-component urethane-based emulsion adhesives, aldehyde compounds, epoxy compounds, Melamine-based compounds, methylol compounds, isocyanate compounds, amine compounds, crosslinking agents such as polyvalent metal salts, etc.). Among them, a water-based adhesive containing an aqueous solution of a polyvinyl alcohol-based resin can be suitably used. In addition, when using a water-based adhesive, it is preferable to carry out the drying process of drying in order to remove the water contained in a water-based adhesive after bonding a polarizing plate and a resin film together. For example, a curing step of curing at a temperature of about 20 to 45° C. may be provided after the drying step.

The above-mentioned active energy ray-curable adhesive refers to an adhesive that is cured by irradiating active energy rays such as ultraviolet rays and electron beams, and examples thereof include curable compositions containing polymerizable compounds and photopolymerization initiators, photopolymerizable compositions containing A curable composition of a reactive resin, a curable composition containing a binder resin and a photoreactive crosslinking agent, etc. are preferably ultraviolet curable adhesives.

In the case of using an active energy ray-curable adhesive, after bonding the polarizer and the resin film together, a drying process is performed as necessary, and then the active energy ray-curable adhesive is cured by irradiating active energy rays. curing process. The light source of active energy rays is not particularly limited, but ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable.

As a method of bonding a polarizing plate and a resin film together, the method of giving surface activation treatments, such as a saponification process, a corona process, a plasma process, etc. to the bonding surface of any one of these at least, is mentioned. When bonding resin films to both surfaces of a polarizing plate, the adhesives used for bonding these resin films may be the same type of adhesives or different types of adhesives.

Another film or layer may be further laminated on the polarizing plate. Specific examples thereof include a brightness enhancing film, an antiglare film, an antireflection film, a diffusion film, a light concentrating film, an adhesive layer other than the adhesive layer (B) in addition to the retardation film described later, Coatings, protective films, etc. A protective film is a film used for the purpose of protecting the surface of an optical film such as a polarizing plate from damage or dirt, and it is customary to attach an optical film with an adhesive layer to, for example, a metal layer or a substrate. Peel off.

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

[1-2] Phase difference plate

In this specification, a retardation plate refers to a member in which a resin film or a resin layer is laminated on at least one surface of a retardation film. The phase difference film contained in the phase difference plate is an optical film showing optical anisotropy, and may be a stretched film obtained by stretching a resin film to about 1.01 to 6 times. The resin of the resin film includes, for example, polyvinyl alcohol-based resins, polyarylate-based resins, polyimide-based resins, polyethersulfone-based resins, polyvinylidene fluoride/poly Methyl methacrylate resin, liquid crystal polyester resin, ethylene-vinyl acetate copolymer saponified product, polyvinyl chloride resin, etc. Among them, a stretched film obtained by uniaxially stretching or biaxially stretching a polycarbonate-based resin film, a cyclic olefin-based resin film, a (meth)acrylic-based resin film, or a cellulose-based resin film is preferable. In addition, in this specification, a zero-retardation film is also included in a retardation film (and can also be used as a protective film). In addition, a film called a uniaxial retardation film, a wide viewing angle retardation film, a low photoelastic modulus retardation film, etc. can also be used as a retardation film.

The zero-retardation film refers to a film in which both the in-plane retardation value _Re and the thickness direction retardation value R _th are -15 to 15 nm. This retardation film is suitably used for the liquid crystal display device of IPS mode. Both the in-plane retardation value R _e and the thickness direction retardation value R _th are preferably -10 to 10 nm, more preferably -5 to 5 nm. The in-plane retardation value _Re and the thickness direction retardation value _Rth referred to here are values at a wavelength of 590 nm.

The in-plane retardation value R _e and the thickness direction retardation value R _th are defined by the following equations, respectively.

R _e =(n _x -n _y )×d

R _th = [(n _x +n _y )/2-n _z ]×d

In the formula, n _x is the refractive index of the slow axis direction (x-axis direction) in the film plane, and n _y is the refractive index of the fast axis direction (the y-axis direction orthogonal to the x axis in the plane) of the film plane, n _z is the refractive index in the film thickness direction (z-axis direction perpendicular to the film surface), and d is the film thickness.

For the zero-retardation film, polyolefin-based resins such as cellulose-based resins, chain polyolefin-based resins, and cyclic polyolefin-based resins, polyethylene terephthalate-based resins, or (meth)acrylic resins can be used. Resin-based resin films, etc. In particular, cellulose-based resins, polyolefin-based resins, or (meth)acrylic-based resins are preferably used from the viewpoints of easy control of the retardation value and easy availability.

In addition, a film exhibiting optical anisotropy by coating and orientation of a liquid crystalline compound, and a film exhibiting optical anisotropy by coating an inorganic layered compound can also be used as a retardation film. Such a retardation film includes: a retardation film called a temperature compensation type retardation film, and a film in which rod-shaped liquid crystals are obliquely oriented sold under the trade name "NH Film" by JX Nippon Mining Nippon Energy Co., Ltd. A film in which discotic liquid crystals are obliquely oriented sold under the trade name "WV Film" by Fujifilm Co., Ltd., a fully biaxially oriented film sold under the trade name "VAC Film" by Sumitomo Chemical Co., Ltd., also sold by Sumitomo Chemical Co., Ltd. A biaxially oriented film sold by Chemical Co., Ltd. under the trade name "New VAC Film" and the like. In addition, the resin film laminated|stacked on at least one surface of a retardation film can be the above-mentioned protective film, for example.

[2] Adhesive layer (B)

As the adhesive constituting the adhesive layer (B) (adhesive layer 20 in FIGS. 1 and 2 ) laminated on at least one side of the optical film (A) of the present invention, existing As known adhesives, adhesives having a base polymer such as acrylic, rubber, polyurethane, silicone, polyvinyl ether, etc. can be used. In addition, an energy ray-curable adhesive, a thermosetting adhesive, or the like may be used. Among them, an adhesive having an acrylic resin excellent in transparency, adhesive force, reworkability, weather resistance, heat resistance, etc. as a base polymer is suitable. In a suitable embodiment of the present invention, the adhesive layer (B) is made of an adhesive composition comprising a (meth)acrylic resin (a), a crosslinking agent (b), and a silane compound (c). The reaction product constitutes.

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

In the present invention, the (meth)acrylic resin (a) that can be contained in the adhesive composition constituting the adhesive layer (B) is preferably derived from (meth)acrylic resin represented by the following formula (I). ) A polymer (hereinafter also referred to as "(meth)acrylic acid) having a structural unit of alkyl acrylate (hereinafter also referred to as "structural unit (I)") as the main component (for example, containing 50% by weight or more of the structural unit) ester polymers").

【Chemical 1】

(In the formula, R ¹⁰ represents a hydrogen atom or a methyl group, R ²⁰ represents an alkyl group with 1 to 20 carbons, the alkyl group can have any structure in straight chain, branched chain or ring, the alkyl group A hydrogen atom may be substituted by an alkoxy group having 1 to 10 carbons.)

In addition, in this specification, "(meth)acryl" means either acryl or methacryl, and "(meth)" of (meth)acrylate etc. has the same meaning.

Examples of the (meth)acrylate represented by the formula (I) include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, ester, n-hexyl acrylate, isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, isononyl acrylate, n-decyl acrylate, iso-octyl acrylate Decyl acrylate, n-dodecyl acrylate, cyclohexyl acrylate, isobornyl acrylate, stearyl acrylate, tert-butyl acrylate, etc. Specific examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl acrylate, ethoxymethyl acrylate, and the like.

A (meth)acrylate polymer may contain 2 or more types of structural units (I). In addition, from the viewpoint of achieving both adhesiveness and durability, it is preferably a copolymer comprising a structural unit having a homopolymer glass transition temperature Tg of 0°C or higher and a structural unit having a homopolymer Tg of less than 0°C. Examples of structural units having a homopolymer having a glass transition temperature (Tg) of 0° C. or higher include methyl acrylate, cyclohexyl acrylate, and isobornyl acrylate. From the viewpoint of durability, it is more preferable to include methyl acrylate. ester or isobornyl acrylate. Examples of structural units having a homopolymer Tg of less than 0°C include ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, acrylic acid Isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, isononyl acrylate, n-decyl acrylate, isodecyl acrylate, n-dodecyl acrylate Among them, alkyl esters and the like preferably contain n-butyl acrylate or 2-ethylhexyl acrylate, and particularly preferably contain n-butyl acrylate.

The (meth)acrylate polymer may contain structural units derived from other monomers other than the structural unit (I). The structural unit derived from another monomer may be 1 type, or may be 2 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 also 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. As a polar functional group, a hydroxyl group, a carboxyl group, a substituted amino group, an unsubstituted amino group etc. are mentioned. Heterocyclic groups, such as an epoxy group, etc. are also mentioned as a polar functional group. Specific examples of (meth)acrylates having such a polar functional group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, -4-hydroxybutyl ester, 2-(2-hydroxyethoxy)ethyl (meth)acrylate, 2-chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-(meth)acrylate -Hydroxypropyl ester, diethylene glycol mono(meth)acrylate and other monomers with hydroxyl groups; acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, (meth)acrylic acid Tetrahydrofurfuryl ester, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran, etc. Heterocyclic monomers; aminoethyl (meth)acrylate, N, N-dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, etc. have substituted or unsubstituted amino groups monomers; monomers with carboxyl groups such as (meth)acrylic acid, carboxyethyl (meth)acrylate, etc. Among them, a monomer having a hydroxyl group is preferable, and a (meth)acrylate having a hydroxyl group is more preferable from the viewpoint of reactivity between the (meth)acrylic resin (a) and the crosslinking agent.

The (meth)acrylate polymer may contain (meth)acrylate having a hydroxyl group, and also contain the above-mentioned other monomers having polar functional groups, so as to prevent the separator from being laminated on the outer surface of the adhesive layer. From the viewpoint of enhancing the peeling force of , it is preferable not to contain a monomer having an amino group substantially. Here, not containing substantially means that it is 1.0 mass parts or less in 100 mass parts of all structural units which comprise (meth)acrylic-type resin (a). Moreover, from a viewpoint of improving the corrosion resistance with respect to transparent electrodes, such as ITO, it is preferable not to contain the monomer which has a carboxyl group substantially. Here, not containing substantially means that it is 2.0 parts by weight or less in 100 parts by weight of all structural units constituting the (meth)acrylic resin (a).

The content of the structural unit derived from a monomer having a polar functional group in the (meth)acrylate polymer is preferably 20 parts by mass or less, more preferably 100 parts by mass of all structural units of the (meth)acrylate polymer. It is 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, particularly preferably 0.5 to 10 parts by mass.

2) Monomers with aromatic groups

The (meth)acrylate polymer may contain a structural unit derived from a monomer having an aromatic group. Examples of monomers having an aromatic group include one (meth)acryloyl group and one or more aromatic rings (such as benzene rings, naphthalene rings, etc.) Benzyl (meth)acrylate. By containing these structural units, the whitening phenomenon of the polarizing plate at the time of a durability test can be suppressed.

Examples of (meth)acrylates having a phenoxyethyl group include 2-phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, ester, oxirane-modified nonylphenol ester of (meth)acrylic acid, 2-(o-phenylphenoxy)ethyl (meth)acrylate, etc. As a structural unit which has a benzyl group, benzyl acrylate etc. are mentioned. Among these, 2-phenoxyethyl (meth)acrylate and 2-(2-phenoxyethoxy)ethyl (meth)acrylate are preferable from the viewpoint of suppressing whitening.

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

3) Acrylamide monomer

The (meth)acrylate polymer may contain a structural unit derived from a monomer having an acrylamide group. As a monomer having an acrylamide group, for example, N-methylolacrylamide, 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)acrylamide, N-[2-( 2-oxo-1-imidazolinyl)ethyl]acrylamide, 2-acryloylamino-2-methyl-1-propanesulfonic acid, N-(methoxymethyl)acrylamide, N-(ethyl Oxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(1-methylethoxymethyl)acrylamide, N-(1-methylpropoxymethyl)acrylamide Amide, N-(2-methylpropoxymethyl)acrylamide [alias: N-(isobutoxymethyl)acrylamide], N-(butoxymethyl)acrylamide, N-(1 , 1-Dimethylethoxymethyl)acrylamide, N-(2-methoxyethyl)acrylamide, N-(2-ethoxyethyl)acrylamide, N-(2-propoxy Ethyl)acrylamide, N-[2-(1-methylethoxy)ethyl]acrylamide, N-[2-(1-methylpropoxy)ethyl]acrylamide, N-[ 2-(2-methylpropoxy)ethyl]acrylamide [alias: N-(2-isobutoxyethyl)acrylamide], N-(2-butoxyethyl)acrylamide, N -[2-(1,1-Dimethylethoxy)ethyl]acrylamide and the like. Bleeding out of additives such as antistatic agents can be suppressed by including these structural units. Among them, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide are preferred , N-(2-methylpropoxymethyl)acrylamide, etc.

Furthermore, as structural units derived from other monomers other than the structural unit (I), structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, structural units derived from molecular Structural units of monomers having multiple (meth)acryloyl groups in them, etc.

Examples of styrene-based monomers include styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, acrylic Alkylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene and other alkylstyrenes; fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene and other halogenated substituted styrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene, etc.

Examples of vinyl-based monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl chloride, vinyl bromide, etc. Vinyl halides; vinylidene halides such as vinylidene chloride; nitrogen-containing heterocyclic aromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; butadiene, isoprene, chloroprene, etc. Conjugated dienes; 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)acrylic acid ester, 1,9-nonanediol 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; Trimethylolpropane tri(meth)acrylate, etc., have 3 (meth)acrylic acid groups in the molecule Acyl monomers, etc.

The (meth)acrylic resin (a) preferably has a weight average molecular weight (Mw) of 500,000 to 2,500,000. When the weight average molecular weight is 500,000 or more, the durability of the pressure-sensitive adhesive layer in a high-humidity heat environment can be improved. When the weight average molecular weight is 2,500,000 or less, the workability at the time of applying the binder solution becomes favorable. The molecular weight distribution (Mw/Mn) represented by the ratio of a weight average molecular weight (Mw) and a number average molecular weight (Mn) is 2-10 normally. The weight average molecular weight can be analyzed by gel permeation chromatography, and is a value in terms of standard polystyrene.

When the (meth)acrylic resin (a) is dissolved in ethyl acetate to 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 this range is advantageous for the improvement of the durability of the optical film with an adhesive layer and the optical laminate containing the optical film, and the reworkability of the optical film with an adhesive layer. The above viscosity can be measured with a Brookfield viscometer.

It is preferable that the glass transition temperature of (meth)acrylic-type resin (a) is -10 degreeC - -60 degreeC from a viewpoint of making adhesiveness and durability compatible. In addition, glass transition temperature can be measured with a differential scanning calorimeter (DSC).

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

As a polymerization initiator, a thermal polymerization initiator and a photopolymerization initiator are mentioned. As a photoinitiator, 4-(2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone is mentioned. Examples of thermal polymerization initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane -1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxypentane Nitrile), dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-hydroxymethylpropionitrile) and other azo compounds; lauryl peroxide tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, neodecyl peroxide Organic peroxides such as tert-butyl peroxypivalate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, hydrogen peroxide, etc. oxide. In addition, a redox-based initiator 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 is mixed with an organic solvent, and a thermal polymerization initiator is added to the resulting solution under a nitrogen atmosphere. A (meth)acrylate polymer can be obtained by stirring the obtained mixture at about 40°C to 90°C, preferably at about 60°C to 80°C for about 3 to 10 hours. In order to control the polymerization reaction, the monomer, the thermal polymerization initiator, or both may be continuously or intermittently added to the reaction system during the polymerization reaction, or may be added in a state 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, methyl isobutyl Ketone and other ketone solvents.

The (meth)acrylic resin (a) may contain two or more types of (meth)acrylate polymers. Examples of such (meth)acrylate polymers include, for example, polymers having a weight average molecular weight in the range of 50,000 to 300,000, mainly composed of the structural unit (I) derived from the above-mentioned (meth)acrylate. Low (meth)acrylate polymer.

[2-2] Crosslinking agent (b)

The adhesive composition forming the adhesive layer (B) preferably contains a crosslinking agent (b). As the crosslinking agent (b), conventional crosslinking agents (such as isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.) From the viewpoints of pot life, durability of the optical film with an adhesive layer, and crosslinking speed, the isocyanate-based compound is preferable.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, and examples include aliphatic isocyanate compounds (such as hexamethylene diisocyanate, etc.), alicyclic isocyanate compounds ( such as isophorone diisocyanate), aromatic isocyanate compounds (such as toluene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, isocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.), etc. In addition, the crosslinking agent (b) may be an adduct (adduct) of the above-mentioned isocyanate compound based on a polyol compound [for example, an adduct based on glycerin, trimethylolpropane, etc.], isocyanuric acid Esterified products, biuret-type compounds, and those obtained by addition reaction of the above-mentioned isocyanate compounds with polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc. Derivatives such as urethane prepolymer type isocyanate compounds. The crosslinking agent (b) can be used individually or in combination of 2 or more types. Among these, toluene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, polyol compounds thereof, or isocyanurate compounds thereof are preferable from the viewpoint of durability.

The ratio of the crosslinking agent (b) to 100 parts by mass of the (meth)acrylic resin (a) 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 (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, it is advantageous for the improvement of durability (peeling resistance), and when it is more than the lower limit, it is advantageous for the improvement of foaming resistance or reworkability.

[2-3] Silane compound (c)

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

Examples of the silane compound (c) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyl Trimethoxysilane, 3-Glycidoxypropyltriethoxysilane, 3-Glycidoxypropylmethyldimethoxysilane, 3-Glycidoxypropylethoxydi Methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methyl Acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc.

The silane compound (c) may contain a silicone oligomer type silane compound. Specific examples of silicone oligomers are shown below in terms of combinations of monomers.

3-Mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane Methoxysilane oligomers, 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomers and other mercaptopropyl-containing oligomers; mercaptomethyltrimethoxysilane-tetramethoxysilane Oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, mercaptomethyltriethoxysilane-tetraethoxysilane Oligomers containing mercaptomethyl groups such as oxysilane oligomers; 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxy Silane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetraethyl Oxysilane Copolymer, 3-Glycidoxypropylmethyldimethoxysilane-Tetramethoxysilane Copolymer, 3-Glycidoxypropylmethyldimethoxysilane-Tetraethyl Oxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane Copolymers containing 3-glycidoxypropyl group such as oxysilane copolymer; 3-methacryloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyl Oxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloxy propyltriethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methylpropene Acyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3 -Oligomers containing methacryloxypropyl groups such as methacryloxypropylmethyldiethoxysilane-tetraethoxysilane oligomers; 3-acryloxypropyltrimethoxy 3-Acryloxypropyltrimethoxysilane Oligomer, 3-Acryloxypropyltrimethoxysilane-Tetraethoxysilane Oligomer, 3-Acryloxypropyltriethoxysilane-Tetramethoxysilane Oxysilane Oligomer, 3-Acryloxypropyltriethoxysilane-Tetraethoxysilane Oligomer, 3-Acryloxypropylmethyldimethoxysilane-Tetramethoxy Silane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxy Silane oligomers, 3-acryloxypropylmethyldiethoxysilane-tetraethoxysilane oligomers and other acryloxypropyl-containing oligomers; vinyltrimethoxysilane-tetraethoxysilane Methoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane Ethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane Alkane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, vinylmethyldiethoxysilane Vinyl silane-tetraethoxysilane oligomers and other vinyl-containing oligomers; 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethyl Oxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethylsilane Dimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetraethoxysilane Amino group-containing copolymers such as methoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer, etc.

The content of the silane compound (c) in the adhesive composition is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 100 parts by mass of the (meth)acrylic resin (a). 2 parts by mass, more preferably 0.1 to 1 part by mass. When content of a silane compound (c) is 0.01 mass part or more, the effect of improving the adhesiveness of an adhesive layer and a board|substrate (glass electrode or transparent electrode) will be acquired easily. Moreover, when content is 10 mass parts or less, bleed-out of a silane compound (c) from an 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 an optical film with an adhesive layer laminated with a separator can be improved, and for example, problems caused by static electricity generated when a separator or a protective film is peeled off can be suppressed.

As an antistatic agent, a usual antistatic agent is mentioned, Preferably it is an ionic antistatic agent. As a cationic component which comprises an ionic antistatic agent, an organic cation, an inorganic cation, etc. are mentioned. Examples of organic cations include pyridinium cations, imidazolium cations, ammonium cations, pyrrolidinium cations, piperidinium cations, sulfonium 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; alkaline earth metal cations such as magnesium cations and calcium cations; and the like. The anion component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, and an anion component containing a fluorine atom is preferable from the viewpoint of improving antistatic performance. Examples of anion components containing fluorine atoms include hexafluorophosphate anion (PF ₆ -), bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N-], bis(fluorine Sulfonyl)imide anion [(FSO ₂ ) ₂ N-], tetrakis(pentafluorophenyl) borate anion [(C ₆ F ₅ ) ₄ B-], etc. These antistatic agents can be used individually or in combination of 2 or more types.

An ionic antistatic agent that is solid at room temperature is particularly preferable in terms of improving the temporal stability of the antistatic performance of the pressure-sensitive adhesive composition. The ratio of an antistatic agent can be 0.01-10 mass parts with respect to 100 mass parts of (meth)acrylic resin (a), for example, Preferably it is 0.1-5 mass parts, More preferably, it can be 0.5-4 mass parts.

[2-5] Other ingredients

The adhesive composition forming the adhesive layer (B) may contain a solvent, a crosslinking catalyst, an ultraviolet absorber, a weather stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment alone or in combination of two or more , inorganic fillers, light-scattering particles, rust inhibitors and other additives. In addition, it is also useful to obtain a harder pressure-sensitive adhesive layer by mixing an ultraviolet-curable compound in the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer and then irradiating it with ultraviolet rays to cure the pressure-sensitive adhesive layer.

The thickness of the pressure-sensitive adhesive layer is usually 2 to 40 μm, preferably 5 to 30 μm, more preferably 10 to 25 μm, from the viewpoint of durability and reworkability of the optical film with the separator-laminated pressure-sensitive adhesive layer. The rework property of the optical film with an adhesive layer becomes favorable that it is below an upper limit, and durability becomes favorable when it is more than a minimum.

Regarding the storage modulus of the adhesive layer (B), the storage modulus G' at 25°C is preferably 0.4 MPa or less, more preferably 0.3 MPa or less, and preferably 0.01 MPa or more. When it is 0.4 MPa or less, the stress relaxation property of an adhesive becomes favorable, and the warping (cell bending) of a liquid crystal panel accompanying shrinkage of a polarizing plate can be relaxed. On the other hand, if the storage elastic modulus G' becomes low (for example, 0.4 MPa or less), there is a tendency that scratches caused by foreign matter will easily occur. According to the present invention that controls the film thickness of the separator (C), even in When using an adhesive layer with a low storage elastic modulus, an optical film with an adhesive layer in which a separator is laminated can be provided which is excellent in an anti-marking effect.

The storage modulus G' at 25°C of the adhesive layer (B) can be measured, for example, by the method described in Examples.

The storage modulus G' of the adhesive layer (B) can be determined, for example, by the blending ((meth)acrylic resin, crosslinking agent, multifunctional active energy, etc.) of the adhesive composition constituting the adhesive layer (B). type/amount of radiation-curable compound) to control.

[3] Diaphragm (C)

The separator (C) constituting the optical film with a separator-laminated pressure-sensitive adhesive layer of the present invention preferably has a surface hardness of 15 or more in Vickers hardness. When the Vickers hardness is 15 or more, the separator (C) has a high surface hardness, and even if it is pressed with foreign matter attached to its surface, it is not easy to cause dents, preventing the optical film from cracking. Excellent effect on damage or scratches caused by foreign matter. In the present invention, the Vickers hardness of the surface of the separator (C) is more preferably 15 or more, still more preferably 17 or more, particularly preferably 19 or more. When the Vickers hardness of the separator (C) is high, the separator (C) is easily broken, so it is usually 200 or less, preferably 150 or less. In addition, Vickers hardness can be measured according to the method described in an Example, for example.

The surface hardness of the separator (C) can be controlled within a desired range by, for example, selecting a plastic film constituting the separator. Specifically, for example, by increasing the stretch ratio when the film is formed into a film to increase the film strength, or slowly cooling the film during film formation to increase the crystal particle size, or increasing the molecular weight of the resin used, etc., Thereby, the surface hardness can be improved.

The separator (C) constituting the optical film with a separator-laminated adhesive layer of the present invention preferably has a bending rigidity of 1 mg or more. Curl|curl of an optical film can be suppressed that bending rigidity is more than the said value. In the present invention, the above-mentioned bending stiffness of the separator (C) is more preferably 1.5 mg or more. The upper limit of the bending stiffness of the separator (C) is usually 100 mg or less, preferably 50 mg or less, more preferably 30 mg or less, from the viewpoint that the separator is easily pulled up when the separator is peeled off. In addition, the said bending stiffness is the value measured by the method described in an Example.

The bending stiffness of the separator (C) can be adjusted to a desired range by, for example, controlling the thickness of the plastic film constituting the separator, film forming conditions (especially stretching conditions), and the like. Specifically, for example, by increasing the thickness of the base material or increasing the tensile modulus of the base material, the bending rigidity can be increased.

In the present invention, the separator (C) is preferably composed of a plastic film and a release layer. Examples of plastic films include polyester films such as polyethylene terephthalate films, polybutylene terephthalate films, and polyethylene naphthalate films; polyester films such as polypropylene films; Olefin film. Among them, a polyethylene terephthalate film is preferable from the viewpoint of optical characteristics and quality, and a biaxially stretched polyethylene terephthalate film is preferable from the viewpoint of making the dimensional stability more excellent. . In addition, the release layer can be formed of, 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 resins, alkyd resins, and acrylic resins. And long-chain alkyl resins, etc. Among them, silicone resins are preferable.

Examples of the silicone resin include those having dimethylpolysiloxane as a basic skeleton. In addition, the silicone resin includes addition reaction type, condensation reaction type, ultraviolet curing type, electron beam curing type, and the like. Among them, the addition reaction type silicone resin has the following advantages: high reactivity, excellent productivity, and compared with the condensation reaction type, the change in peeling force after production is small, and there is no cure shrinkage, so it is preferably used.

Specific examples of the above-mentioned addition reaction type silicone resin include, for example, vinyl, allyl, propenyl, hexenyl, etc. having 2 to 10 carbon atoms at the terminal and/or side chain of the molecule. alkenyl organopolysiloxane, etc. When using such an addition reaction type silicone resin, it is preferable to use a crosslinking agent and a catalyst together.

Examples of the above-mentioned crosslinking agent include organopolysiloxanes having at least two hydrogen atoms bonded to silicon atoms in one molecule, specifically, dimethylhydrogensiloxy-terminated bismuth Methylsiloxane-Methylhydrogensiloxane Copolymer, Trimethylsiloxy-blocked Dimethicone-Methylhydrogensiloxane Copolymer, Trimethylsiloxy-blocked Methylsiloxane Hydrogen polysiloxane, poly (hydrogen silsesquioxane), etc.

Examples of the catalyst include platinum metals such as particulate platinum, particulate platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, and rhodium. Department of compounds, etc. By using such a catalyst, the hardening reaction of the composition for peeling layer formation can be advanced more efficiently.

When using a silicone resin in the composition for peeling layer formation, it is preferable to add a peeling regulator, such as MQ resin.

In addition, additives may be appropriately blended in the composition for peeling layer formation. As an additive, a catalyst, a dye, a dispersing agent, etc. are mentioned. Furthermore, in order to make the viscosity at the time of coating into an appropriate range, you may contain a dispersion medium or a solvent suitably in the composition for peeling layer formation.

Examples of the dispersion medium or solvent include organic solvents such as aromatic hydrocarbons such as toluene, fatty acid esters such as ethyl acetate, ketones such as methyl ethyl ketone (MEK), and aliphatic hydrocarbons such as hexane and heptane.

The separator (C) can be produced, for example, by applying a composition for forming a release layer diluted in a solvent to one side of a plastic film by the following method. Examples thereof include gravure coating, bar coating, spray coating, spin coating, air knife coating, roll coating, doctor blade coating, gate roll coating, and die coating. Among them, the gravure coating method and the bar coating method are preferable, and the gravure coating method is more preferable.

Moreover, as a method of heating and drying the composition for peeling layer formation, the method of heat-drying with a hot-air drying oven etc. is mentioned, for example. The drying temperature is, for example, not less than 50°C and not more than 150°C. In addition, the drying time is preferably, for example, 10 seconds to 5 minutes.

The film thickness of the separator (C) can be controlled by the thickness of the plastic film and the thickness of the release layer. Among them, the thickness of the plastic film plays a dominant role, and can be controlled by selecting a polyester film having a target thickness. The thickness of the plastic film is preferably 45 μm or more, more preferably 47 μm or more, and still more preferably 50 μm or more. The upper limit of the film thickness of the plastic film is not particularly limited, but is usually 200 μm or less, and is preferably 150 μm or less, more preferably 100 μm or less, since the separator is easily pulled up when the separator is peeled off. The thickness of the release layer (when dry) is preferably 40 to 300 nm, more preferably 50 to 200 nm, and still more preferably 80 to 150 nm. By setting the thickness of the peeling layer to 40 nm or more, it is possible to suppress uneven peeling force due to variations in the coating amount, and to make the thickness of the peeling layer 300 nm or less, so that blocking can be suppressed.

[4] Configuration and manufacturing method of an optical film with an adhesive layer laminated with a separator

For example, as shown in FIG. 1 , an optical film 1 with an adhesive layer laminated with a separator includes an optical film 10 and an adhesive layer 20 laminated on at least one side thereof, and is laminated on the outer surface of the adhesive layer 20. Diaphragm 30. An adhesive layer 20 is laminated on one surface 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 implement a surface activation treatment (for example, plasma treatment, corona treatment, etc.), corona treatment is particularly preferred.

An antistatic layer may be provided separately between the optical film 10 and the pressure-sensitive adhesive layer 20 . As the antistatic layer, silicon-based materials such as polysiloxane; inorganic metal-based materials such as tin-doped indium oxide and tin-doped antimony oxide; organic polymers such as polythiophene, polystyrene sulfonic acid, and polyaniline, etc. Molecular materials.

The optical film 1 with an adhesive layer laminated with a separator can be obtained, for example, by dissolving or dispersing the components constituting the adhesive composition for forming the adhesive layer (B) in a solvent to obtain a composition containing A solvent-based adhesive composition is then applied to the release-treated surface of the separator 30 and dried to form the adhesive layer 20, and the adhesive layer 20 is laminated (transferred) on the optical film 10 surfaces.

The optical film with the separator-laminated adhesive layer of the present invention preferably has a surface hardness of 15 or more in Vickers hardness. When the Vickers hardness is 15 or more, the optical film with an adhesive layer has a high surface hardness, and even if it is pressed with foreign matter attached to its surface, it is less likely to be dented, preventing The optical film is excellent in the effect of the damage|wound or scratch by a foreign object. In the present invention, the Vickers hardness of the surface of the optical film with the pressure-sensitive adhesive layer laminated with the separator is more preferably 17 or more, and still more preferably 19 or more. If the Vickers hardness is high, the optical film with the separator-laminated pressure-sensitive adhesive layer is likely to be broken, so the upper limit of the Vickers hardness of the optical film with the separator-laminated pressure-sensitive adhesive layer is usually 200 or less, preferably 150 or less. In addition, Vickers hardness can be measured according to the method described in an Example, for example.

The surface hardness of the optical film with the separator-laminated pressure-sensitive adhesive layer can be controlled within a desired range by, for example, selecting a plastic film constituting the separator. Specifically, for example, the strength of the film is increased by increasing the stretch ratio when the film is formed, or the crystal grain size is increased by slowly cooling the film during film formation, or the molecular weight of the resin used is increased. , which can increase the surface hardness.

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, "part" and "%" which show the usage-amount and content are mass basis unless otherwise indicated.

1. Diaphragm

(1) Fabrication of diaphragm

(i) Preparation of composition for peeling layer formation

Silicone resin solution (manufactured by Toray-Dow Corning Co., trade name: BY24-571, solid content 30% by mass) was diluted and mixed with a solvent of toluene/MEK=1/1 so as to be 30 parts by mass in terms of solid content and to have a solid content concentration of 1.0 mass%. 2 parts by mass of a platinum-based catalyst (manufactured by Toray Dow Corning Corporation, trade name: SRX-212, solid content: 100% by mass) was added to this solution to prepare a composition for peeling layer formation.

(ii) Fabrication of Spacer 1

A biaxially stretched polyethylene terephthalate (PET) film A (PET50T-193 manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 50 μm, an end orientation angle of 8 degrees, and a haze of 5% was prepared. Next, on one side of the biaxially stretched PET film A, the composition for forming a peeling layer obtained above was coated with a bar coater so that the thickness after drying became 0.1 μm, and dried at 120° C. for 1 minute to form a peeling layer. Separator 1 (Spacer 1) was obtained.

(iii) Fabrication of Spacer 2

A biaxially stretched polyethylene terephthalate (PET) film B (PET38R-64 manufactured by Toray Corporation) having a thickness of 38 μm, an end orientation angle of 6 degrees, and a haze of 10% was prepared. Next, on one side of the biaxially stretched PET film A, the composition for forming a peeling layer obtained above was coated with a bar coater so that the thickness after drying became 0.1 μm, and dried at 120° C. for 1 minute to form a peeling layer. Separator 2 (Spacer 2) was obtained.

(2) Determination of physical properties of the diaphragm

(i) Surface hardness

Separator 1 and separator 2 prepared above were cut into 40mm×40mm, respectively, and the release-treated surface (peeling surface) of the separator was bonded to 40mm×40mm glass via an adhesive layer with a film thickness of 20 μm. Next, in an atmosphere of 23°C and 55%, a load is applied to the evaluation sample bonded to the glass at a pressing speed of 0.1N/5s using an ultra-micro hardness tester (FISCHERSCOPEHM2000: manufactured by Fisher Instruments Co., Ltd.). , the Vickers hardness was measured while maintaining a load of 0.1 N for 5 seconds. The results are shown in Table 1.

(ii) Bending stiffness

<measurement preparation>

After the diaphragm 1 and diaphragm 2 produced above were cut into test pieces with a size of 25.4 mm×25.4 mm, one end of the test piece was mounted on a Gurley type testing machine (Gurley hardness tester (Gurley stiffness Tester) ( Electric type) 2094-M: Manufactured by Kumagai Riki Kogyo Co., Ltd.) on the chuck of the movable arm. The chuck is fixed in alignment with the position of 1 inch (25.4 mm) of the scale on the movable arm A, and the test piece is moved to a position away from the apex of the vibrator B in advance. Next, attach a 5g weight to the position of the load mounting hole a (1 inch) located below the fulcrum of the vibrator B so that it is in a vertical state without vibration.

<measurement operation>

Make the movable arm move right or left at a constant speed at 2 times/min. Read the scale R when the lower part of the test piece comes into contact with the vibrator B and is separated from the vibrator B, and substitute it into the following conversion formula to calculate the bending stiffness. The results are shown in Table 1.

S=((aWa+bWb+cWc)/5)×(1 ² /b)×11.1×R(mg)

S: bending stiffness (mg)

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

Wa, Wb, Wc: Mass of the weight installed in the load mounting hole (g)

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

b: Width of test piece (inches)

R: Scale reading value

【Table 1】

2. Production of optical film and optical film with adhesive layer laminated with separator

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

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 - 2.5 parts by mass of hydroxyethyl ester, 200 parts by mass of ethyl acetate, and 0.08 parts by mass of 2,2'-azobisisobutyronitrile, and the air in the reaction container was replaced with nitrogen. The reaction solution was heated up to 60 degreeC, stirring in this nitrogen atmosphere, it was made to react for 16 hours, and it cooled to room temperature. Here, the molecular weight was measured by the method mentioned later about a part of the obtained solution, and it confirmed that the (meth)acrylate polymer with a weight average molecular weight of 2 million was produced|generated.

The weight average molecular weight (Mw) of the said (meth)acrylic resin is the weight average molecular weight of polystyrene conversion measured on the following conditions using gel permeation chromatography (GPC).

〔Measurement conditions〕

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

・GPC column (passed in the following order): manufactured by Tosoh Corporation

TSK guard column HXL-H

TSK gel GMHXL (×2)

TSK gel G2000HXL

·Measurement solvent: tetrahydrofuran

·Measurement temperature: 40℃

(2) Preparation of adhesive layer

(a) Preparation of Adhesive Composition (A)

100 parts by mass of the (meth)acrylate polymer obtained in the above step (1) (value in terms of solid content; the same applies hereinafter), trimethylolpropane-modified phthalide as the isocyanate-based crosslinking agent (B) 0.20 parts by mass of methyl diisocyanate (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name "Takenate D110N") and 3-mercaptopropyltrimethoxysilane as a silane coupling agent (C) and methyltriethoxysilane A coating solution of an adhesive composition (A) was obtained by mixing 0.30 parts by mass of a condensate (manufactured by Shin-Etsu Chemical Co., Ltd., brand name "X41-1810"), fully stirring, and diluting with ethyl acetate.

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

After coating the adhesive composition (A) prepared in (a) above with an applicator on the release-treated surface (peeling surface) of the spacer 1 obtained above so that the thickness after drying becomes 20 μm, heat it at 100° C. Drying was carried out for 1 minute to obtain an adhesive layer 1 as an adhesive sheet 1 .

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

The pressure-sensitive adhesive layer 2 as the pressure-sensitive adhesive sheet 2 was obtained in the same manner as the preparation of the pressure-sensitive adhesive layer 1 except that the spacer 2 obtained above was used instead of the spacer 1 .

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

(1) Example 1: Optical Film A1 with an Adhesive Layer Laminated with a Separator

(i) Preparation of polarizing film (polarizer) A

A polyvinyl alcohol film ("Kuraray Poval Film VF-PS#7500", produced by Kuraray Co., Ltd.) with an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol%, and a thickness of 75 μm was immersed in pure water at 37°C, and then heated at 30°C. It was immersed in an aqueous solution (iodine/potassium iodide/water (weight ratio)=0.04/1.5/100) containing iodine and potassium iodide at °C. Then, it 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. Next, the film was washed with pure water at 10° C., and then dried at 85° C. to obtain a polarizing film having a thickness of about 28 μm in which polyvinyl alcohol was adsorbed and oriented with iodine. Stretching is mainly carried out in the process of iodine dyeing and boric acid treatment, and the total stretching ratio is 5.3 times.

(ii) Preparation of Optical Film A

A transparent protective film made of a triacetyl cellulose film with a thickness of 40 μm ("KC4UYW", Konica Minolta Opto Co., Ltd. ), a cycloolefin-based resin film ("ZF14-023", manufactured by Japan ZEON Co., Ltd.) with a thickness of 23 μm was attached to the surface of the obtained polarizing film A opposite to the above-mentioned transparent protective film, and an optical film A (polarizing plate ). The thickness of this optical film A was about 91 μm.

(iii) Production of Optical Film A1 (Polarizing Plate) with PSA Layer Laminated with Separator

The surface (adhesive layer layer) of the adhesive sheet 1 produced in the above (b1) opposite to the spacer 1 is bonded to the obtained optical film A with a bonded cycloolefin-based resin film using a laminator. After that, it was cured for 7 days at a temperature of 23° C. and a relative humidity of 65%, to obtain an optical film A1 (polarizing plate) with an adhesive layer laminated with a separator having the layer constitution shown in Table 2. The surface hardness (Vickers hardness) of the optical film A1 with the pressure-sensitive adhesive layer in which the separator was laminated was 20.4.

(II) Comparative Example 1: Optical Film A2 with PSA Layer Laminated with Separator

Except for using the adhesive sheet 2 produced in the above (b2) instead of the adhesive sheet 1, similar to the production of the optical film A1 with an adhesive layer laminated with a separator, the optical film A1 having the properties shown in Table 2 was obtained. The optical film A2 with the adhesive layer laminated|stacked with the separator in layers. The surface hardness (Vickers hardness) of the optical film A2 with the pressure-sensitive adhesive layer laminated with the separator was 13.5.

(III) Example 2: Optical Film B1 with an Adhesive Layer Laminated with a Separator

(i) Preparation of polarizing film (polarizer) B

A polyvinyl alcohol film ["Kuraray Poval Film VF-PE#3000", produced by Kuraray Co., Ltd.] with 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, and then heated at 30°C. It was immersed in an aqueous solution (iodine/potassium iodide/water (weight ratio)=0.04/1.5/100) containing iodine and potassium iodide at °C. Then, it 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. Next, the film was washed with pure water at 10° C., and then dried at 85° C. to obtain a polarizing film B having a thickness of about 12 μm in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching is mainly carried out in the process of iodine dyeing and boric acid treatment, and the total stretching ratio is 5.3 times.

(ii) Preparation of Optical Film B

A transparent protective film ("25KCHCN-TC") obtained by applying a hard coat layer of 7 μm to a triacetyl cellulose film with a thickness of 25 μm was attached to one side of the obtained polarizing film B via an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin. ", Toppan Printing Co., Ltd.), a cycloolefin-based resin film with a thickness of 23 μm ("ZF14-023", manufactured by Nippon ZEON Co., Ltd.) was bonded to the surface of the obtained polarizing film B opposite to the above-mentioned transparent protective film, and produced Form an optical film B (polarizing plate). The thickness of this optical film B was about 67 μm.

(iii) Production of Optical Film B1 (Polarizing Plate) with PSA Layer Laminated with Separator

The surface (adhesive layer layer) of the adhesive sheet 1 prepared in (b) above which is opposite to the spacer 1 is bonded to the obtained optical film B with a cycloolefin-based resin film bonded by a laminator. After that, it was cured for 7 days under the conditions of a temperature of 23° C. and a relative humidity of 65%, to obtain an optical film B1 (polarizing plate) with an adhesive layer laminated with a separator having the layer constitution shown in Table 2. The surface hardness (Vickers hardness) of the optical film B1 with the pressure-sensitive adhesive layer laminated with the separator was 18.7.

(IV) Comparative Example 2: Optical Film B2 with an Adhesive Layer Laminated with a Separator

Except for using the adhesive sheet 2 produced in the above (b2) instead of the adhesive sheet 1, the optical film B1 with the adhesive layer laminated with the separator was obtained in the same manner as the preparation of the optical film B1 with the adhesive layer shown in Table 2. An optical film B2 composed of an adhesive layer laminated with a separator. The surface hardness (Vickers hardness) of the optical film B2 with the pressure-sensitive adhesive layer laminated with the separator was 12.7.

(V) Reference Example 1: Optical Film C1 with an Adhesive Layer Laminated with a Separator

(i) Preparation of polarizing film (polarizer) C

After immersing a polyvinyl alcohol film ("Kuraray Poval Film VF-PS#7500", manufactured by Kuraray Co., Ltd.) with an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol%, and a thickness of 75 μm in pure water at 37° C. It was immersed in an aqueous solution (iodine/potassium iodide/water (weight ratio)=0.04/1.5/100) containing iodine and potassium iodide at °C. Then, it 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. Next, the film was washed with pure water at 10° C., and then dried at 85° C. to obtain a polarizing film C having a thickness of about 28 μm in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching is mainly carried out in the process of iodine dyeing and boric acid treatment, and the total stretching ratio is 5.3 times.

(ii) Preparation of Optical Film C

A transparent protective film ("KC6UAW", manufactured by Konica Minolta Opto Co., Ltd. ), a cycloolefin-based resin film ("ZB12-050135", manufactured by Japan ZEON Co., Ltd.) with a thickness of 50 μm was bonded to the surface opposite to the above-mentioned transparent protective film of the obtained polarizing film to prepare an optical film C (polarizing plate). The thickness of this optical film C is about 138 μm.

(iii) Production of Optical Film C1 (Polarizing Plate) with PSA Layer Laminated with Separator

The surface (adhesive layer layer) of the adhesive sheet 1 prepared in (b) above which is opposite to the spacer 1 is bonded to the obtained optical film C with a bonded cycloolefin-based resin film using a laminator. Then, it was cured for 7 days at a temperature of 23° C. and a relative humidity of 65%, to obtain an optical film C1 (polarizing plate) with an adhesive layer laminated with a separator having the layer composition shown in Table 2.

(VI) Reference Example 2: Optical Film C2 with an Adhesive Layer Laminated with a Separator

Except for using the adhesive sheet 2 produced in the above (b2) instead of the adhesive sheet 1, the optical film C1 with the adhesive layer laminated with the separator was obtained in the same manner as the preparation of the optical film C1 with the adhesive layer shown in Table 2. The optical film C2 with the adhesive layer laminated|stacked with a separator was composed of layers.

The surface hardness of the optical films A1, A2, B1, B2, C1, and C2 with the adhesive layer laminated with the separator produced above is as follows: After each film was cut into a size of 40 mm x 40 mm, it was laminated with the separator. The opposite surface of one side is bonded to 40 mm × 40 mm glass through an adhesive layer with a film thickness of 20 μm, and an ultra-micro hardness tester (FISCHERSCOPE HM2000: manufactured by Fisher Instruments Co., Ltd.) is used in an atmosphere of 23° C. and 55%. ) After applying a load to the evaluation sample bonded to glass at a pressurization rate of 0.1N/5 seconds, the obtained Vickers hardness was measured by maintaining a load of 0.1N for 5 seconds.

【Table 2】

3. Evaluation of the effect of preventing damage/marking of the optical film with the adhesive layer laminated with the separator

The effect of preventing optical film damage/marking with the separator-laminated pressure-sensitive adhesive layer was evaluated according to the following method.

Optical films A1 (Example 1), B1 (Example 2), A2 (Comparative Example 1), B2 (Comparative Example 2), C1 (Reference Example 1) and C2 ( Reference example 2) Each polarizing plate was cut into a size of 120 mm×75 mm so that the direction of the stretching axis of the polarizing plate was the long side, and the surface of the separator was placed on a hard and flat surface. The indentation resistance test was performed on the separator surface of the provided optical film with the pressure-sensitive adhesive layer on which the separator was laminated using a scratch-type hardness tester (hardness test pencil model 318/318S of Erichsen Corporation). This test is a test to check whether or not a dent occurs when a hemispherical tungsten carbide chip (with a radius of about 0.75 mm) is pressed against an arbitrary position on the surface of the diaphragm with a predetermined constant force.

After the scratch hardness tester was pressed against the surface of the diaphragm with a pressure of 0.1 N for 5 seconds, the scratch hardness tester was released from the surface of the diaphragm. This operation was carried out at five locations of the optical film with the adhesive layer on which the separator was laminated, so that five scratches were formed on the surface of the separator. Immediately after the tester was detached from the surface of the separator (initial) and 24 hours later, the state of the depression remaining on the surface of the separator was visually confirmed, and it was judged as "not disappearing" when the depression remained, and judged when the depression did not remain. for "disappear". Table 3 shows the "Number of Undisappeared" at each time.

【table 3】

In the optical films with an adhesive layer of Examples 1 and 2 in which the film thickness of the separator is 45 μm or more and the film thickness of the polarizing plate (optical film) is 100 μm or less, the scratch hardness tester was detached from the surface of the separator for 24 hours After that, one punching mark (dent) did not remain. In contrast, in the optical films with pressure-sensitive adhesive layers of Comparative Examples 1 and 2 in which the film thickness of the separator was less than 45 μm, scratches remained even after 24 hours had elapsed since the scratch hardness tester was detached from the surface of the separator. In particular, in Comparative Example 2, all scratch marks remained even after 24 hours. In addition, in the optical film having a thickness exceeding 100 μm (Reference Examples 1 and 2), since the film thickness of the optical film itself (138 μm) is relatively thick, it is difficult to cause dents, regardless of the thickness of the separator, scratches after 24 hours Both disappear.

<Measurement of storage modulus>

A plurality of pressure-sensitive adhesive layers were laminated so as to have a thickness of 0.6 mm. A cylinder having a diameter of 8 mm (height: 0.6 mm) was punched out from the obtained pressure-sensitive adhesive layer, and this was used as a sample for measurement of the storage elastic modulus G'.

About the said sample, the storage modulus (MPa) was measured on the following conditions by the torsional shear method using the viscoelasticity measuring apparatus (made by Physica Corporation, MCR300) based on JISK7244-6.

〔Measurement conditions〕

Measurement frequency: 1Hz

Measuring temperature: 25°C

The storage elastic modulus of the adhesive layer formed from the above adhesive composition (A) was 0.085 MPa.

(VII) Example 3: Optical Film A3 with Adhesive Layer Laminated with Separator

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

94 parts by mass of n-butyl acrylate, 5.0 parts by mass of 2-hydroxyethyl acrylate, 1.0 parts by mass of acrylic acid, and 200 parts by mass of ethyl acetate were put into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen gas introduction pipe. and 0.08 parts by mass of 2,2'-azobisisobutyronitrile, and the air in the reaction container was replaced with nitrogen. The reaction solution was heated up to 60 degreeC, stirring in this nitrogen atmosphere, it was made to react for 16 hours, and it cooled to room temperature. Here, the molecular weight was measured by the method of the said description about a part of the obtained solution, and it confirmed that the (meth)acrylate polymer with a weight average molecular weight of 2 million was produced|generated.

(2) Preparation of Adhesive Composition (B)

100 parts by mass of the (meth)acrylate polymer obtained in the above step (1) (value in terms of solid content; the same applies below), trimethylolpropane-modified toluene diisocyanate as the isocyanate-based crosslinking agent (B) [Soken Chemical Co., Ltd., product name "L-45"] 1.0 parts by mass of γ-glycidoxypropyltrimethoxysilane [Shin-Etsu Chemical Co., Ltd. "KBM-403] as a silane coupling agent (C) ”] 0.20 parts by mass, 10 parts by mass of tris(acryloyloxyethyl) isocyanurate [manufactured by Toagosei Co., Ltd., product name “M-315”] as a polyfunctional active energy ray-curable compound, and 1 part by mass of 1-hydroxycyclohexyl phenyl ketone [manufactured by Ciba Specialty Chemicals, product name "Irgacure 184"] as an initiator was mixed and well stirred, and diluted with ethyl acetate to obtain an adhesive composition (B) coating solution.

(3) Preparation of adhesive layer (adhesive sheet 3)

After applying the adhesive composition (B) prepared in (a2) above to the release-treated surface (peeling layer) of the spacer 1 obtained above using a coating machine so that the thickness after drying becomes 20 μm, It dried for 1 minute at ℃, and the adhesive layer 3 which is the adhesive sheet 3 was obtained. The pressure-sensitive adhesive sheet 3 was produced by irradiating ultraviolet rays (UV) from the release sheet side under the following conditions.

<UV irradiation conditions>

· Electrodeless lamps manufactured by Fusion use H valves

·Illuminance 600mW/cm ² , light intensity 150mJ/cm ²

As the UV illuminance and light quantity meter, "UVPF-36" manufactured by EYE GRAPHICS Co., Ltd. was used.

<Measurement of storage modulus>

The storage elastic modulus at 25° C. of the adhesive layer formed from the adhesive composition (B) was measured by the same method as the above-mentioned measurement method in the adhesive composition (A). The storage modulus at 25° C. of the adhesive layer formed from the adhesive composition (B) was 0.55 MPa.

(4) Preparation of optical film A3 (polarizing plate) with adhesive layer laminated with separator

The surface (adhesive layer layer) of the adhesive sheet 3 produced in the above (3) opposite to the spacer 1 is bonded to the surface of the optical film B on which the cycloolefin-based resin film is bonded using a laminator. , was cured for 7 days under conditions of a temperature of 23° C. and a relative humidity of 65%, to obtain an optical film A3 (polarizing plate) with a separator-laminated adhesive layer having the layer configuration shown in Table 4.

The same method as in Example 1 was used to evaluate the effect of preventing scratches/marks on the optical film A3 with the separator-laminated pressure-sensitive adhesive layer. The results are shown in Table 4.

【Table 4】

Symbol Description

1: Optical film with adhesive layer laminated with separator, 2: Polarizer, 3: (First) resin film, 4: (Second) resin film, 5: Protective film, 6: Hard coat layer, 10 : Optical film, 20: Adhesive layer, 30: Separator.

Claims (4)

1. An optical film with an adhesive layer laminated with a separator, comprising a separator (C) laminated via an adhesive layer (B) on at least one side of the optical film (A), The film thickness of the separator (C) is 45 μm or more, and the film thickness of the optical film (A) is 100 μm or less. 2 . The optical film with an adhesive layer in which a separator is laminated according to claim 1 , wherein the separator (C) has a Vickers hardness of 15 or more on its surface. 3 . 3 . The optical film with a separator-laminated adhesive layer according to claim 1 , wherein the separator (C) has a bending stiffness of 1 mg or more. 4 . 4. The optical film with a separator-laminated adhesive layer according to any one of claims 1 to 3, wherein the adhesive layer (B) has a storage modulus G' at 25° C. of 0.4 Below MPa.