JP2016101716A - Optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical laminate having excellent durability between an adhesive layer and a transparent electrode.SOLUTION: An optical laminate 1A comprises an optical film, an adhesive layer 10 and a transparent electrode 20 laminated in the stated order, where the adhesive layer 10 is formed from a composition comprising a (meth) acrylic acid ester polymer, a crosslinking agent and a compound represented by formula (I) (A is a C1-20 alkanediyl group or the like; Ris a C1-5 alkyl group; R-Rindependently represent a C1-5 alkyl group or alkoxy group).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical laminate.

  An optical laminate represented by a polarizing plate is widely used as a member constituting a liquid crystal display device. The optical laminate is usually distributed on one side with a pressure-sensitive adhesive layer, and a release film is stuck on the pressure-sensitive adhesive layer. After peeling off the release film, the exposed pressure-sensitive adhesive layer is removed. It is bonded to the liquid crystal cell.

In a liquid crystal display device, the dimensional change of the optical laminate as a constituent member occurs under high-temperature or high-humidity heat conditions or under repeated heating and cooling, and foaming of the adhesive layer or the optical laminate and the adhesive layer And / or between the pressure-sensitive adhesive layer and the liquid crystal cell.
As a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer having good adhesion, heat resistance and moisture resistance to a glass substrate, for example, Patent Document 1 discloses 3-glycidoxypropyltrimethoxysilane as a silane coupling agent. A pressure-sensitive adhesive composition containing only a silane compound having an epoxy group such as the above is disclosed.
On the other hand, in recent years, liquid crystal display devices have been developed for mobile devices having a touch panel function such as smartphones, tablets, and in-car car navigation systems. In such liquid crystal display devices, the adhesive layer is transparent. In many cases, the structure is arranged so as to be in direct contact with the electrode, and adhesion and durability between the transparent electrode and the pressure-sensitive adhesive layer are particularly important. However, the durability between the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition containing only the silane compound having an epoxy group as the silane coupling agent and the transparent electrode is not sufficient, and improvement is desired. It was.

JP-A-4-223403

  This invention provides the optical laminated body with favorable durability between an adhesive layer and a transparent electrode.

（式中、Ａは、炭素数１〜２０のアルカンジイル基または炭素数３〜２０の二価の脂環式炭化水素基を表し、該アルカンジイル基および該脂環式炭化水素基を構成する−ＣＨ_２−は、−Ｏ−または−ＣＯ−に置き換わっていてもよく、Ｒ^１は、炭素数１〜５のアルキル基を表し、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立して、炭素数１〜５のアルキル基または炭素数１〜５のアルコキシ基を表す。）
で示されるシラン化合物とを含有し、（メタ）アクリル酸エステル重合体中のカルボキシル基を有する単量体に由来する構造単位の含有量が、（メタ）アクリル酸エステル重合体の全構造単位１００質量部に対して、２質量部未満である粘着剤組成物から形成される光学積層体。
［２］式（Ｉ）で示されるシラン化合物が、式（ＩＩ）：

（式中、Ｒ^１、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ上記と同一の意味を表し、Ｒ^７は、炭素数１〜５のアルキル基を表し、ｍは、１〜２０の整数を表す。）
で示されるシラン化合物である［１］に記載の光学積層体。
［３］式（ＩＩ）中、ｍが４〜２０の整数である［２］に記載の光学積層体。
［４］粘着剤組成物中の式（Ｉ）で示されるシラン化合物の含有量が、（メタ）アクリル酸エステル重合体１００重量部に対して、０．０１質量部〜１０質量部である［１］〜［３］のいずれかに光学積層体。
［５］（メタ）アクリル酸エステル重合体が、ヒドロキシ基を有する単量体に由来する構造単位を含む［１］〜［４］のいずれかに記載の光学積層体。
［６］（メタ）アクリル酸エステル重合体が、芳香族基を有する単量体に由来する構造単位を含む［１］〜［５］のいずれかに記載の光学積層体。
［７］（メタ）アクリル酸エステル重合体が、ホモポリマーのガラス転移温度が０℃以上の（メタ）アクリル酸エステルに由来する構造単位と、ホモポリマーのガラス転移温度が０℃以下の（メタ）アクリル酸エステルに由来する構造単位とを含む［１］〜［６］のいずれかに記載の光学積層体。
［８］（メタ）アクリル酸エステル重合体の重量平均分子量が、５０万〜２５０万である［１］〜［７］のいずれかに記載の光学積層体。
［９］架橋剤が、イソシアネート化合物である［１］〜［８］のいずれかに記載の光学積層体。
［１０］粘着剤組成物が、帯電防止剤をさらに含有する［１］〜［９］のいずれかに記載の光学積層体。
［１１］［１］〜［１０］のいずれかに記載の光学積層体を含む液晶表示装置。
［１２］（メタ）アクリル酸エステル重合体と架橋剤と式（Ｉ）：

（式中、Ａは、炭素数１〜２０のアルカンジイル基または炭素数３〜２０の二価の脂環式炭化水素基を表し、該アルカンジイル基および該脂環式炭化水素基を構成する−ＣＨ_２−は、−Ｏ−または−ＣＯ−に置き換わっていてもよく、Ｒ^１は、炭素数１〜５のアルキル基を表し、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立して、炭素数１〜５のアルキル基または炭素数１〜５のアルコキシ基を表す。）
で示されるシラン化合物とを含有し、（メタ）アクリル酸エステル重合体中のカルボキシル基を有する単量体に由来する構造単位の含有量が、（メタ）アクリル酸エステル重合体の全構造単位１００質量部に対して、２質量部未満である、透明電極用粘着剤組成物。 The present invention includes the following.
[1] An optical laminate in which an optical film, a pressure-sensitive adhesive layer, and a transparent electrode are laminated in this order, and the pressure-sensitive adhesive layer comprises a (meth) acrylate polymer, a crosslinking agent, and a formula (I):

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the alkanediyl group and the alicyclic hydrocarbon group. —CH ₂ — may be replaced by —O— or —CO—, R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are And each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)
The content of structural units derived from the monomer having a carboxyl group in the (meth) acrylic acid ester polymer is 100% of all structural units of the (meth) acrylic acid ester polymer. The optical laminated body formed from the adhesive composition which is less than 2 mass parts with respect to a mass part.
[2] The silane compound represented by the formula (I) is represented by the formula (II):

(Wherein R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ each have the same meaning as described above, R ⁷ represents an alkyl group having 1 to 5 carbon atoms, and m represents 1 to 20) Represents an integer.)
The optical laminate according to [1], which is a silane compound represented by
[3] The optical layered body according to [2], wherein m is an integer of 4 to 20 in formula (II).
[4] The content of the silane compound represented by the formula (I) in the pressure-sensitive adhesive composition is 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer. The optical laminate according to any one of [1] to [3].
[5] The optical laminate according to any one of [1] to [4], wherein the (meth) acrylic acid ester polymer includes a structural unit derived from a monomer having a hydroxy group.
[6] The optical laminate according to any one of [1] to [5], wherein the (meth) acrylic acid ester polymer includes a structural unit derived from a monomer having an aromatic group.
[7] A (meth) acrylic acid ester polymer is a structural unit derived from a (meth) acrylic acid ester having a homopolymer glass transition temperature of 0 ° C. or higher, and a homopolymer glass transition temperature of 0 ° C. or lower (meta The optical laminated body in any one of [1]-[6] containing the structural unit derived from acrylate ester.
[8] The optical laminate according to any one of [1] to [7], wherein the (meth) acrylic acid ester polymer has a weight average molecular weight of 500,000 to 2,500,000.
[9] The optical laminate according to any one of [1] to [8], wherein the crosslinking agent is an isocyanate compound.
[10] The optical laminate according to any one of [1] to [9], wherein the pressure-sensitive adhesive composition further contains an antistatic agent.
[11] A liquid crystal display device comprising the optical laminate according to any one of [1] to [10].
[12] (Meth) acrylic acid ester polymer, crosslinking agent and formula (I):

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the alkanediyl group and the alicyclic hydrocarbon group. —CH ₂ — may be replaced by —O— or —CO—, R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are And each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)
The content of structural units derived from the monomer having a carboxyl group in the (meth) acrylic acid ester polymer is 100% of all structural units of the (meth) acrylic acid ester polymer. The adhesive composition for transparent electrodes which is less than 2 mass parts with respect to mass parts.

  According to the present invention, an optical laminate having good durability can be provided.

It is a cross-sectional schematic diagram which shows an example of the layer structure of the optical laminated body of this invention. It is a cross-sectional schematic diagram which shows an example of another layer structure of the optical laminated body of this invention. It is a cross-sectional schematic diagram which shows an example of another layer structure of the optical laminated body of this invention.

  The optical laminate of the present invention is an optical laminate in which an optical film, an adhesive layer and a transparent electrode are laminated in this order.

[Optical film]
The optical film means a film having optical properties such as a polarizing plate and a retardation plate, and the film may be a single layer or may have two or more layers.

<Polarizing plate>
A polarizing plate contains a polarizing film, Preferably, the protective film is laminated | stacked on the single side | surface or both surfaces of the polarizing film.
A polarizing film is a film having a function of extracting linearly polarized light from incident natural light. For example, a polarizing film in which a dichroic dye such as iodine or a dichroic organic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film. Is mentioned. The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and a copolymer of vinyl acetate and a monomer copolymerizable with vinyl acetate. Examples of the monomer copolymerizable with vinyl acetate include unsaturated carboxylic acid, olefin, vinyl ether, unsaturated sulfonic acid, acrylamide having an ammonium group, and the like.

  The saponification degree of the polyvinyl alcohol resin is usually 85 mol% to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with an aldehyde. The degree of polymerization of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

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

  The polarizing film is, for example, a step of uniaxially stretching the original film, a step of dyeing the film with a dichroic dye and adsorbing the dichroic dye, a step of treating the film with an aqueous boric acid solution, and A step of washing the film with water is performed, and finally the film is dried and manufactured. The film thickness of a polarizing film is 1-30 micrometers normally.

  A transparent resin film is mentioned as a protective film laminated | stacked on the single side | surface or both surfaces of a polarizing film. Examples of the transparent resin include cellulose resins, acrylic resins, polyester resins, polyolefin resins, polycarbonate resins, polyether ether ketone resins, polysulfone resins, and the like, and cellulose resins and acrylic resins are preferable. The protective film is a conventional additive in the technical field of the present invention (for example, an ultraviolet absorber, an infrared absorber, an organic dye, a pigment, an inorganic dye, an antioxidant, an antistatic agent, a surfactant, a lubricant, a dispersion). In particular, UV rays such as salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, triazine compounds, cyanoacrylate compounds, nickel complex salts are included in order to increase the weather resistance of the polarizing plate. Absorbents are preferred.

  Examples of the cellulose resin include cellulose acetate ester, propionate ester, butyrate ester, and mixed ester thereof. Of these, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate and cellulose acetate butyrate are preferable. Examples of the commercially available cellulose resin film include “Fujitac TD” (trade name, sold by Fuji Film Co., Ltd.) and “Konica Minolta TAC Film KC” (trade name, sold by Konica Minolta Opto).

  The acrylic resin film is a film formed from an acrylic resin obtained by mixing and melting and kneading a methacrylic resin and additives added as necessary. Methacrylic resin is a polymer mainly composed of methacrylic acid ester. The methacrylic resin may be a homopolymer of one type of methacrylic acid ester, a copolymer of two or more types of methacrylic acid ester, or a copolymer of methacrylic acid ester and acrylic acid ester. It may be a polymer. Examples of the methacrylic acid esters include C1-C4 alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate. As the acrylic ester that can be copolymerized with the methacrylic ester, an alkyl ester of acrylic acid having 1 to 8 carbon atoms is preferable. Specifically, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl acrylate Examples include hexyl. Further, it may be a copolymer with a compound having at least one polymerizable carbon-carbon double bond in the molecule (for example, an aromatic vinyl compound such as styrene or a vinylcyan compound such as acrylonitrile).

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

  The acrylic resin film preferably contains acrylic rubber particles from the viewpoint of impact resistance and film-forming property of the film. The content of the acrylic rubber particles is preferably 5% by mass or more, more preferably 10% by mass or more with respect to 100% by mass of the acrylic resin. When the content of acrylic rubber particles is too large, the surface hardness of the film is lowered, and when the film is subjected to surface treatment, the solvent resistance to the organic solvent in the surface treatment agent is lowered. Content of an acrylic rubber particle is 80 mass% or less, Preferably it is 60 mass% or less.

  If necessary, the protective film may be provided with one or more surface treatment layers on the opposite side of the surface in contact with the polarizing film. As the surface treatment layer, a hard coat layer, an antiglare layer, an antireflection layer are provided. And an antistatic layer.

  The protective film may be provided with a film having optical characteristics such as a brightness enhancement film, a light collecting film, and a diffusion film on the opposite side of the surface in contact with the polarizing film.

<Phase difference plate>
The retardation plate includes a retardation film, and the protective film is laminated as necessary. The retardation film is an optical film showing optical anisotropy, for example, polyvinyl alcohol resin, polycarbonate resin, polyester resin, polyarylate resin, polyimide resin, olefin resin, cycloolefin resin, Styrene resin, sulfone resin such as polysulfone and polyethersulfone, polyvinylidene fluoride / polymethyl methacrylate, liquid crystal polyester resin, cellulose resin containing triacetyl cellulose, saponified ethylene-vinyl acetate copolymer, polychlorinated Examples include a stretched film obtained by stretching a resin film made of a vinyl resin, an acrylic resin, or the like to about 1.01 to 6 times. Among these, a resin film obtained by uniaxially or biaxially stretching a cycloolefin-based resin film, a cellulose-based resin film, a polyester-based resin film, and a polycarbonate film is preferable. In the present specification, the retardation film includes a zero retardation film, and also includes a film called a uniaxial retardation film, a low photoelasticity retardation film, a wide viewing angle retardation film, or the like.

  Examples of the cycloolefin resin include thermoplastic resins having a cycloolefin monomer unit such as norbornene, tetracyclododecene, or derivatives thereof. Cycloolefin ring-opening polymers and two or more kinds of cycloolefin resins can be used. It may be a hydrogenated product of a ring-opening copolymer, or an addition copolymer of a cycloolefin and a chain olefin or an aromatic compound having a vinyl group, and a polar group is introduced. May be.

  Commercially available thermoplastic cycloolefin resins are, for example, produced by TOPAS ADVANCED POLYMERS GmbH, Germany, and sold by "TOPAS" and JSR, which are sold by Polyplastics in Japan. “ARTON (registered trademark)”, “ZEONEX (registered trademark)” and “ZEONOR (registered trademark)” sold by Nippon Zeon Co., Ltd., “Apel (registered trademark)” sold by Mitsui Chemicals, Inc. ".

  Examples of a method for obtaining a film by forming a cycloolefin-based resin include known film-forming methods such as a solvent casting method and a melt extrusion method. A cycloolefin-based resin film or a film is further stretched to give a phase difference. Cycloolefin resin films are also commercially available. Specifically, “ARTON (registered trademark) (Arton) film” sold by JSR Corporation, “ZEONOR (registered trademark) (ZEONOR) film” sold by Nippon Zeon Corporation, Sekisui Chemical Examples include “Essina (registered trademark)” and “SCA40” (trade name) sold by Kogyo Co., Ltd.

  The cellulose resin film is a film made of a cellulose part or a completely esterified product. Examples thereof include films made of cellulose acetate, propionate, butyrate, mixed esters thereof, and the like. Of these, triacetyl cellulose film, diacetyl cellulose film, cellulose acetate propionate film and cellulose acetate butyrate film are preferable. Examples of commercially available cellulose resin films include “Fujitac TD” sold by Fuji Film Co., Ltd. and “Konica Minolta TAC Film KC” sold by Konica Minolta Opto.

  The polyester-based resin is a polymer obtained by condensation polymerization of a dibasic acid and a dihydric alcohol, and examples thereof include polyethylene terephthalate. The polycarbonate-based resin is a polymer having a carbonate bond (—O—CO—O—) in the main chain, and examples thereof include those obtained by condensation polymerization of bisphenol A and phosgene.

The zero Letters retardation film, and the retardation R _th for the front retardation R _e and the thickness direction, both a -15～15Nm, refers to isotropic film optically. Examples of the zero retardation film include a resin film made of a cellulose resin, a polyolefin resin (a chain polyolefin resin, a polycycloolefin resin, etc.) or a polyethylene terephthalate resin, and the retardation value can be easily controlled and obtained. Cellulose resin or polyolefin resin is preferable because it is easy. The zero retardation film can also be used as a protective film. Zero retardation films include “Z-TAC” (trade name) sold by FUJIFILM Corporation, “Zero Tac (registered trademark)” sold by Konica Minolta Opto, and ZEON Corporation. "ZF-14" (trade name) sold by

  As a method of obtaining a film by forming a cellulose-based resin or a polyolefin-based resin, a solvent casting method in which a resin dissolved in a solvent is cast onto a metal band or drum, and the solvent is removed by drying to obtain a film. Examples thereof include a melt extrusion method in which a film is obtained by heating a resin above its melting temperature, kneading and extruding from a die, and cooling with a cooling drum. Of these, the melt extrusion method is suitable for polyolefin resins from the viewpoint of productivity, and the solvent cast method is suitable for cellulose resins.

  Examples of the retardation film include a film that exhibits optical anisotropy by applying and orienting a liquid crystalline compound, and a film that exhibits optical anisotropy by applying an inorganic layered compound. Examples of such a film include a film referred to as a temperature compensation type retardation film, “NH film” (trade name; a film in which rod-shaped liquid crystal is tilted and aligned) sold by JX Nippon Mining & Energy Co., Ltd., Fuji “WV film” (trade name; film with disc-shaped liquid crystal tilted) sold by Film Co., Ltd. “VAC film” (trade name; fully biaxially oriented type) sold by Sumitomo Chemical Co., Ltd. And “new VAC film” (trade name: biaxially oriented film) sold by Sumitomo Chemical Co., Ltd.

（式中、Ａは、炭素数１〜２０のアルカンジイル基または炭素数３〜２０の二価の脂環式炭化水素基を表し、該アルカンジイル基および該脂環式炭化水素基を構成する−ＣＨ_２−は、−Ｏ−または−ＣＯ−に置き換わっていてもよく、Ｒ^１は、炭素数１〜５のアルキル基を表し、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立して、炭素数１〜５のアルキル基または炭素数１〜５のアルコキシ基を表す。）
で示されるシラン化合物とを含有する粘着剤組成物から形成され、該粘着剤組成物に含まれる（メタ）アクリル酸エステル重合体中のカルボキシル基含有モノマーに由来する構造単位の含有量は、（メタ）アクリル酸エステル重合体の全構造単位１００質量部に対して、２質量部未満である。
かかる粘着剤組成物は、透明電極と光学フィルム等の他の部材とを貼り合わせるための、透明電極用粘着剤組成物として有用である。 [Adhesive layer]
The pressure-sensitive adhesive layer in the optical laminate of the present invention comprises a (meth) acrylic acid ester polymer, a crosslinking agent, and a formula (I):

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the alkanediyl group and the alicyclic hydrocarbon group. —CH ₂ — may be replaced by —O— or —CO—, R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are And each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)
The content of the structural unit derived from the carboxyl group-containing monomer in the (meth) acrylic acid ester polymer contained in the pressure-sensitive adhesive composition is formed from a pressure-sensitive adhesive composition containing It is less than 2 mass parts with respect to 100 mass parts of all the structural units of a methacrylic acid ester polymer.
This pressure-sensitive adhesive composition is useful as a pressure-sensitive adhesive composition for transparent electrodes for bonding a transparent electrode and another member such as an optical film.

  The thickness of the pressure-sensitive adhesive layer is usually 10 μm or more and 30 μm or less, preferably 10 μm or more and 20 μm or less. When the thickness of the pressure-sensitive adhesive layer is 30 μm or less, the adhesiveness in a humid heat environment is further improved, and the possibility of occurrence of floating or peeling between the transparent electrode and the pressure-sensitive adhesive layer tends to be low. In addition, the reworkability tends to be improved. When the thickness is 10 μm or more, even if the dimensions of the optical film change, the pressure-sensitive adhesive layer tends to follow and change due to the dimensional change. Therefore, the liquid crystal display device including the optical laminate of the present invention has white spots and colors. Unevenness tends to be suppressed. For example, the thickness of the pressure-sensitive adhesive layer bonded to the liquid crystal cell is generally 25 μm, but in the optical layered body of the present invention, the pressure-sensitive adhesive layer has a thickness of 20 μm or less. Demonstrate sufficient performance as a layer.

（式中、Ｒ^1０は、水素原子またはメチル基を表し、Ｒ^2０は、炭素数１〜１４のアルキル基または炭素数７〜２０のアラルキル基を表し、該アルキル基または該アラルキル基の水素原子は、炭素数１〜１０のアルコキシ基で置き換わっていてもよい。）
で示される（メタ）アクリル酸エステルが挙げられる。
なお、本明細書において、「（メタ）アクリル酸」とは、アクリル酸またはメタクリル酸のいずれでもよいことを意味し、（メタ）アクリレートなどの「（メタ）」も同様の意味である。 <(Meth) acrylic acid ester polymer>
A (meth) acrylic acid ester polymer means a polymer whose main component is a structural unit derived from a (meth) acrylic acid ester. The (meth) acrylic acid ester polymer may include a structural unit derived from a monomer other than one or more (meth) acrylic acid esters (for example, a structural unit derived from a monomer having a polar functional group). .
As the (meth) acrylic acid ester, the following formula (III)

(In the formula, R ¹⁰ represents a hydrogen atom or a methyl group, R ²⁰ represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and a hydrogen atom of the alkyl group or the aralkyl group. May be replaced by an alkoxy group having 1 to 10 carbon atoms.)
The (meth) acrylic acid ester shown by these is mentioned.
In the present specification, “(meth) acrylic acid” means either acrylic acid or methacrylic acid, and “(meth)” such as (meth) acrylate has the same meaning.

In the formula (III), R ²⁰ is preferably an alkyl group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms.

As (meth) acrylic acid ester,
Linear alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, lauryl acrylate;
Branched alkyl esters of acrylic acid such as isobutyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate;
Linear alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, lauryl methacrylate;
Branched alkyl esters of methacrylic acid such as isobutyl methacrylate, 2-ethylhexyl methacrylate, isooctyl methacrylate;
Alkoxyalkyl esters of (meth) acrylic acid such as 2-methoxyethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, ethoxymethyl methacrylate; and (meth) acrylic acid such as benzyl acrylate and benzyl methacrylate Aralkyl ester is mentioned.

The (meth) acrylic acid ester polymer may contain structural units derived from two or more kinds of (meth) acrylic acid esters, and the homopolymer has a glass transition temperature (Tg) of 0 ° C. or lower. It is preferable to include a structural unit derived from an ester and a structural unit derived from a (meth) acrylic acid ester having a Tg of a homopolymer of 0 ° C. or higher.
As the (meth) acrylic acid ester having a Tg of 0 ° C. or lower, n-butyl acrylate is preferable. As the (meth) acrylic acid ester having a Tg of 0 ° C. or higher, methyl acrylate is preferable.

As a structural unit derived from a monomer other than (meth) acrylic acid ester, a structural unit derived from a monomer having a polar functional group is preferable, and a structure derived from (meth) acrylic acid ester having a polar functional group Units are more preferred. Examples of polar functional groups include hydroxy groups, substituted or unsubstituted amino groups, and heterocyclic groups such as epoxy groups.
As monomers other than (meth) acrylic acid ester,
(Meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 4-hydroxybutyl, (meth) acrylic acid 2- (2-hydroxyethoxy) ethyl, (meth) acrylic acid Monomers having a hydroxy group such as 2-chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate;
Acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, A monomer having a heterocyclic group such as 2,5-dihydrofuran;
Examples thereof include monomers having a substituted or unsubstituted amino group such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylate. Especially, the monomer which has a hydroxyl group is preferable, and the (meth) acrylic acid ester which has a hydroxyl group is more preferable at the reactive point of a (meth) acrylic acid ester polymer and a crosslinking agent.

  The content of the structural unit derived from the monomer having a polar functional group in the (meth) acrylic acid ester polymer is preferably 10 with respect to 100 parts by mass of all structural units of the (meth) acrylic acid ester polymer. It is 0.5 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, further preferably 0.5 parts by mass or more and 5 parts by mass or less, particularly preferably 1 part by mass or more and 5 parts by mass or less.

  Monomers other than (meth) acrylic acid esters include monomers having a carboxyl group as a polar functional group (for example, acrylic acid, methacrylic acid, etc.), but carboxyls in (meth) acrylic acid ester polymers The content of the structural unit derived from the monomer having a group is less than 2 parts by mass with respect to 100 parts by mass of all structural units of the (meth) acrylic acid ester polymer. Corrosion of the electrode can be suppressed.

The (meth) acrylic acid ester polymer may contain a structural unit derived from a monomer having an aromatic group. As a monomer having an aromatic group, a monomer having one olefinic double bond and one or more aromatic rings (for example, a benzene ring, a naphthalene ring, etc.) in the molecule and having no polar functional group. A monomer is preferable, and a (meth) acrylic acid ester having a phenoxyethyl group is more preferable.
Examples of (meth) acrylic acid ester having a phenoxyethyl group include 2-phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, and ethylene oxide-modified nonylphenol ester of (meth) acrylic acid. , (Meth) acrylic acid 2- (o-phenylphenoxy) ethyl and the like. Of these, 2-methoxyethyl (meth) acrylate and 2- (2-phenoxyethoxy) ethyl (meth) acrylate are preferable.

  The content of the structural unit derived from the monomer having an aromatic group in the (meth) acrylic acid ester polymer is preferably 20 with respect to 100 parts by mass of all structural units of the (meth) acrylic acid ester polymer. It is 4 parts by mass or more, more preferably 4 parts by mass or more and 20 parts by mass or less, and further preferably 4 parts by mass or more and 16 parts by mass or less.

  As structural units derived from monomers other than (meth) acrylic acid esters, structural units derived from (meth) acrylic acid esters having an alicyclic structure, structural units derived from styrene monomers, vinyl-based units Examples include a structural unit derived from a monomer, a structural unit derived from a monomer having a plurality of (meth) acryloyl groups in the molecule, and a structural unit derived from a (meth) acrylamide monomer.

  Examples of the alicyclic structure include a cycloparaffin structure having 5 or more carbon atoms, preferably 5 to 7 carbon atoms. Examples of (meth) acrylic acid esters having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methyl cyclohexyl acrylate, trimethyl cyclohexyl acrylate, and tert-butyl acrylate. Cyclohexyl, α-ethoxy acrylate, cyclohexyl phenyl acrylate, isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methyl cyclohexyl methacrylate, trimethyl cyclohexyl methacrylate, tert-butyl cyclohexyl methacrylate And cyclohexyl phenyl methacrylate.

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

  Examples of vinyl monomers include: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, etc .; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride, etc. Examples thereof include vinylidene halides; nitrogen-containing heteroaromatic vinyls such as vinylpyridine, vinylpyrrolidone and vinylcarbazole; conjugated dienes such as butadiene, isoprene and chloroprene; and unsaturated nitriles such as acrylonitrile and methacrylonitrile.

  As monomers having a plurality of (meth) acryloyl groups in the molecule, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di ( Two (meth) acryloyl groups in the molecule such as (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate A monomer having three (meth) acryloyl groups in the molecule such as trimethylolpropane tri (meth) acrylate.

  (Meth) acrylamide monomers include N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (4- Hydroxybutyl) (meth) acrylamide, N- (5-hydroxypentyl) (meth) acrylamide, N- (6-hydroxyhexyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl ( (Meth) acrylamide, N-isopropyl (meth) acrylamide, N- (3-dimethylaminopropyl) (meth) acrylamide, N- (1,1-dimethyl-3-oxobutyl) (meth) acrylamide, N- [2- ( 2-oxo-1-imidazolidinyl) ethyl] (meth) acrylamide, -Acryloylamino-2-methyl-1-propanesulfonic acid, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) (meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (1-methyl) Ethoxymethyl) (meth) acrylamide, N- (1-methylpropoxymethyl) (meth) acrylamide, N- (2-methylpropoxymethyl) (meth) acrylamide, N- (butoxymethyl) (meth) acrylamide, N- ( 1,1-dimethylethoxymethyl) (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N- (2-ethoxyethyl) (meth) acrylamide, N- (2-propoxyethyl) (meth) Acrylamide, N- [2- (1-methylethoxy) ethyl] ( T) acrylamide, N- [2- (1-methylpropoxy) ethyl] (meth) acrylamide, N- [2- (2-methylpropoxy) ethyl] (meth) acrylamide, N- (2-butoxyethyl) (meth) ) Acrylamide, N- [2- (1,1-dimethylethoxy) ethyl] (meth) acrylamide, and the like. Of these, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide and N- (2-methylpropoxymethyl) acrylamide are preferable.

  The (meth) acrylic acid ester polymer is preferably a monomer having a hydroxy group (preferably a (meth) acrylic acid ester having a hydroxy group) in addition to a structural unit derived from a (meth) acrylic acid ester. And structural units derived from monomers having aromatic groups (preferably one olefinic double bond and one or more aromatic rings in the molecule (for example, benzene ring, naphthalene ring, etc. And at least one structural unit selected from the group consisting of monomers derived from a monomer having no polar functional group.

  The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer is preferably 500,000 to 2.5 million. When the weight average molecular weight is 500,000 or more, the adhesive property of the pressure-sensitive adhesive layer in a high-humidity heat environment is improved, and the possibility of floating or peeling between the transparent electrode and the pressure-sensitive adhesive layer tends to be reduced. And reworkability tends to be improved. When the weight average molecular weight is 2.5 million or less, even if the dimensions of the optical film are changed, the pressure-sensitive adhesive layer is likely to follow and change due to the change in the dimensions. Therefore, the liquid crystal display device including the optical laminate of the present invention is white. There is a tendency for missing and uneven color to be suppressed. The molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 2-10. The weight average molecular weight can be analyzed by gel permeation chromatography and is a value in terms of standard polystyrene.

  The pressure-sensitive adhesive composition may contain two or more kinds of (meth) acrylic acid ester polymers, for example, a structural unit derived from a (meth) acrylic acid ester represented by the formula (III) as a main component, and a weight Examples thereof include polymers having an average molecular weight of 50,000 to 300,000.

  When a (meth) acrylic acid ester polymer is dissolved in ethyl acetate to prepare a polymer solution having a concentration of 20% by weight, the viscosity of the polymer solution at 25 ° C. is 20 Pa · s or less (meta ) Acrylic acid ester polymer is preferable, and a (meth) acrylic acid ester polymer of 0.1 to 7 Pa · s is more preferable. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition containing the (meth) acrylic acid ester polymer having a viscosity of 20 Pa · s or less at this time has improved adhesion in a high-humidity heat environment, and is a transparent electrode. There is a tendency that the possibility of floating or peeling between the adhesive layer and the pressure-sensitive adhesive layer tends to be low, and the reworkability tends to be improved. The viscosity can be measured with a Brookfield viscometer.

  From the viewpoint of adhesiveness, the glass transition temperature of the (meth) acrylic acid ester polymer is preferably −10 ° C. to −60 ° C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

  The (meth) acrylic acid ester polymer 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 a (meth) acrylic acid ester polymer, polymerization is usually carried out in the presence of a polymerization initiator. The usage-amount of a polymerization initiator is 0.001-5 mass parts normally with respect to a total of 100 mass parts of all the monomers which comprise a (meth) acrylic acid ester polymer. The (meth) acrylic acid ester polymer can also be produced by a method of polymerizing with active energy rays such as ultraviolet rays.

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

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

<Crosslinking agent>
The pressure-sensitive adhesive composition contains a crosslinking agent. Examples of the crosslinking agent include isocyanate compounds, epoxy compounds, aziridine compounds, and metal chelate compounds.

  The isocyanate compound is a compound having at least two isocyanato groups (—NCO) in the molecule. Specific examples include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like. In addition, adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolprone, and dimers and trimers of these isocyanate compounds are also included. Two or more isocyanate compounds may be combined.

  The epoxy compound is a compound having at least two epoxy groups in the molecule. Specifically, bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether N, N-diglycidylaniline, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane and the like. Two or more epoxy compounds may be combined.

  An aziridine compound is a compound having an ethyleneimine skeleton, that is, a skeleton having a three-membered ring composed of one nitrogen atom and two carbon atoms in the molecule. Specifically, diphenylmethane-4,4′-bis (1-aziridinecarboxamide), toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1- (2-methylaziridine) ), Tris-1-aziridinylphosphine oxide, hexamethylene-1,6-bis (1-aziridinecarboxamide), trimethylolpropane-tris-β-aziridinylpropionate, tetramethylolmethane-tris-β- Examples thereof include aziridinyl propionate.

  Examples of the metal chelate compound include compounds in which acetylacetone or ethyl acetoacetate is coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium.

  Of these, isocyanate compounds are preferred, tolylene diisocyanate, adducts obtained by reacting tolylene diisocyanate and polyol, tolylene dimer dimer, tolylene diisocyanate trimer, xylylene diisocyanate, xylylene diisocyanate. Adducts obtained by reacting styrene and polyol, dimer of xylylene diisocyanate, trimer of xylylene diisocyanate, hexamethylene diisocyanate, adduct obtained by reacting hexamethylene diisocyanate and polyol, hexamethylene diisocyanate More preferred are dimers of the above, trimers of hexamethylene diisocyanate, and mixtures thereof.

  Content of the crosslinking agent in an adhesive composition is 0.1-1 mass part normally with respect to 100 mass parts of (meth) acrylic acid ester polymers. When the amount of the crosslinking agent is 0.1 parts by mass or more, the durability of the pressure-sensitive adhesive layer tends to be improved, and when it is 1 part by mass or less, the optical laminate of the present invention is applied to a liquid crystal display device. The white spots are not noticeable.

（式中、Ａは、炭素数１〜２０のアルカンジイル基または炭素数３〜２０の二価の脂環式炭化水素基を表し、該アルカンジイル基および該脂環式炭化水素基を構成する−ＣＨ_２−は、−Ｏ−または−ＣＯ−に置き換わっていてもよく、Ｒ^１は、炭素数１〜５のアルキル基を表し、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立して、炭素数１〜５のアルキル基または炭素数１〜５のアルコキシ基を表す。）
で示されるシラン化合物を含有する。これにより、本発明の光学積層体において、粘着剤層と透明電極との密着性が向上する。 <Silane compound>
The pressure-sensitive adhesive composition has the formula (I):

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the alkanediyl group and the alicyclic hydrocarbon group. —CH ₂ — may be replaced by —O— or —CO—, R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are And each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)
The silane compound shown by these is contained. Thereby, in the optical laminated body of this invention, the adhesiveness of an adhesive layer and a transparent electrode improves.

Examples of the alkanediyl group having 1 to 20 carbon atoms include methylene group, 1,2-ethanediyl group, 1,3-propanediyl group, 1,4-butanediyl group, 1,5-pentanediyl group, and 1,6-hexanediyl group. Group, 1,7-heptanediyl group, 1,8-octanediyl group, 1,9-nonanediyl group, 1,10-decandiyl group, 1,12-dodecandiyl group, 1,14-tetradecandiyl group, 1,16- Examples include a hexadecandiyl group, a 1,18-octadecandiyl group, and a 1,20-icosanediyl group. Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include a 1,3-cyclopentanediyl group and a 1,4-cyclohexanediyl group. Examples of the group in which —CH ₂ — constituting the alkanediyl group and the alicyclic hydrocarbon group are replaced by —O— or —CO— include —CH ₂ CH ₂ —O—CH ₂ CH ₂ —, —CH ₂ CH ₂ —O—CH ₂ CH ₂ —O—CH ₂ CH ₂ —, —CH ₂ CH ₂ —O—CH ₂ CH ₂ —O—CH ₂ CH ₂ —O—CH ₂ CH ₂ —, —CH _{2 CH 2 -CO-O-CH 2} CH 2 -, - CH 2 CH 2 -O-CH 2 CH 2 -CO-O-CH 2 CH 2 -, - CH 2 CH 2 CH 2 CH 2 -O-CH 2 CH ₂ - and _{-CH 2 CH 2 CH 2 CH 2} -O-CH 2 CH 2 CH 2 CH 2 - and the like.

  Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, and a pentyl group. Methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, tert-butoxy group and pentyloxy group.

As the silane compound represented by the formula (I),
Bis (trimethoxysilyl) methane,
Bis (triethoxysilyl) methane,
Bis (tripropoxysilyl) methane,
Bis (tributoxysilyl) methane,
Bis (tripentyloxysilyl) methane,
Bis (dimethoxymethylsilyl) methane,
Bis (dimethoxyethylsilyl) methane,
Bis (dimethoxypropylsilyl) methane,
Bis (dimethoxyethylsilyl) methane,
Bis (dimethoxypropylsilyl) methane,
Bis (diethoxymethylsilyl) methane,
Bis (dipropoxymethylsilyl) methane,
Bis (methoxydimethylsilyl) methane,
1- (trimethylsilyl) -1- (methoxydimethylsilyl) methane 1- (trimethylsilyl) -1- (dimethoxymethylsilyl) methane 1- (trimethoxysilyl) -1- (triethoxysilyl) methanebis (dimethoxyethoxysilyl) methane 1,2-bis (trimethoxysilyl) ethane,
1,2-bis (triethoxysilyl) ethane,
1,2-bis (tripropoxysilyl) ethane,
1,2-bis (tributoxysilyl) ethane,
1,2-bis (tripentyloxysilyl) ethane,
1,2-bis (dimethoxymethylsilyl) ethane,
1,2-bis (dimethoxyethylsilyl) ethane,
1,2-bis (dimethoxypropylsilyl) ethane,
1,2-bis (dimethoxyethylsilyl) ethane,
1,2-bis (dimethoxypropylsilyl) ethane,
1,2-bis (diethoxymethylsilyl) ethane,
1,2-bis (dipropoxymethylsilyl) ethane,
1,2-bis (methoxydimethylsilyl) ethane,
1- (trimethylsilyl) -2- (methoxydimethylsilyl) ethane 1- (trimethylsilyl) -2- (dimethoxymethylsilyl) ethane 1- (trimethoxysilyl) -2- (triethoxysilyl) ethane 1,2-bis ( Dimethoxyethoxysilyl) ethane 1,3-bis (trimethoxysilyl) propane,
1,3-bis (triethoxysilyl) propane,
1,3-bis (tripropoxysilyl) propane,
1,4-bis (trimethoxysilyl) butane,
1,4-bis (triethoxysilyl) butane,
1,4-bis (tripropoxysilyl) butane,
1,4-bis (tributoxysilyl) butane,
1,4-bis (tripentyloxysilyl) butane,
1,4-bis (dimethoxymethylsilyl) butane,
1,4-bis (dimethoxyethylsilyl) butane,
1,4-bis (dimethoxypropylsilyl) butane,
1,4-bis (dimethoxyethylsilyl) butane,
1,4-bis (dimethoxypropylsilyl) butane,
1,4-bis (diethoxymethylsilyl) butane,
1,4-bis (dipropoxymethylsilyl) butane,
1,4-bis (methoxydimethylsilyl) butane,
1- (trimethylsilyl) -4- (methoxydimethylsilyl) butane 1- (trimethylsilyl) -4- (dimethoxymethylsilyl) butane 1- (trimethoxysilyl) -4- (triethoxysilyl) butane 1,4-bis ( Dimethoxyethoxysilyl) butane 1,5-bis (trimethoxysilyl) pentane,
1,5-bis (triethoxysilyl) pentane,
1,5-bis (tripropoxysilyl) pentane,
1,6-bis (trimethoxysilyl) hexane,
1,6-bis (triethoxysilyl) hexane,
1,6-bis (tripropoxysilyl) hexane,
1,6-bis (tributoxysilyl) hexane,
1,6-bis (tripentyloxysilyl) hexane,
1,6-bis (dimethoxymethylsilyl) hexane,
1,6-bis (dimethoxyethylsilyl) hexane,
1,6-bis (dimethoxypropylsilyl) hexane,
1,6-bis (dimethoxyethylsilyl) hexane,
1,6-bis (dimethoxypropylsilyl) hexane,
1,6-bis (diethoxymethylsilyl) hexane,
1,6-bis (dipropoxymethylsilyl) hexane,
1,6-bis (methoxydimethylsilyl) hexane,
1- (trimethylsilyl) -6- (methoxydimethylsilyl) hexane 1- (trimethylsilyl) -6- (dimethoxymethylsilyl) hexane 1- (trimethoxysilyl) -6- (triethoxysilyl) hexane 1,6-bis ( Dimethoxyethoxysilyl) hexane 1,8-bis (trimethoxysilyl) octane,
1,8-bis (triethoxysilyl) octane,
1,8-bis (tripropoxysilyl) octane,
1,8-bis (tributoxysilyl) octane,
1,8-bis (tripentyloxysilyl) octane,
1,8-bis (dimethoxymethylsilyl) octane,
1,8-bis (dimethoxyethylsilyl) octane,
1,8-bis (dimethoxypropylsilyl) octane,
1,8-bis (dimethoxyethylsilyl) octane,
1,8-bis (dimethoxypropylsilyl) octane,
1,8-bis (diethoxymethylsilyl) octane,
1,8-bis (dipropoxymethylsilyl) octane,
1,8-bis (methoxydimethylsilyl) octane,
1- (trimethylsilyl) -8- (methoxydimethylsilyl) octane 1- (trimethylsilyl) -8- (dimethoxymethylsilyl) octane 1- (trimethoxysilyl) -8- (triethoxysilyl) octane 1,8-bis ( Dimethoxyethoxysilyl) octane 1,10-bis (trimethoxysilyl) decane,
1,12-bis (trimethoxysilyl) dodecane,
1,14-bis (trimethoxysilyl) tetradecane,
1,16-bis (trimethoxysilyl) hexadecane,
Examples include 1,18-bis (trimethoxysilyl) octadecane and 1,20-bis (trimethoxysilyl) icosane.

（式中、Ｒ^１、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ上記と同一の意味を表し、Ｒ^７は、炭素数１〜５のアルキル基を表し、ｍは、１〜２０の整数を表す。）
で示されるシラン化合物が好ましく、ｍが４〜２０の整数である式（ＩＩ）で示されるシラン化合物がより好ましい。 Among them, the formula (II):

(Wherein R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ each have the same meaning as described above, R ⁷ represents an alkyl group having 1 to 5 carbon atoms, and m represents 1 to 20) Represents an integer.)
The silane compound shown by Formula (II) whose m is an integer of 4-20 is more preferable.

  The pressure-sensitive adhesive composition may contain other known silane coupling agents and silicone oligomers in addition to the silane compound represented by the formula (I) as long as the performance is not impaired. Other silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3- Glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc. are mentioned.

Specific examples of the silicone oligomer are shown below. In the following specific examples, the silicone oligomer is expressed in the form of a combination of monomers.
3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane Mercaptopropyl group-containing oligomers such as oligomers;

  Mercaptomethyl group-containing oligomers such as mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, mercaptomethyltriethoxysilane-tetraethoxysilane oligomer ;

  3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane -Tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3 -Methacryloyloxypropylmethyldiethoxysilane-tetraeth Methacryloyloxypropyl group-containing oligomers such silane oligomer;

  3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane -Tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3 -Acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligo Acryloyloxypropyl group-containing oligomers over like;

  Vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, Vinyl group-containing oligomers such as vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, and vinylmethyldiethoxysilane-tetraethoxysilane oligomer.

  Content of the silane compound shown by Formula (I) in an adhesive composition is 0.01 mass part-10 mass parts normally with respect to 100 mass parts of (meth) acrylic acid ester polymers, Preferably 0.01 parts by mass to 2 parts by mass, more preferably 0.03 parts by mass to 2 parts by mass, and particularly preferably 0.03 parts by mass to 1 part by mass. When the content of the silane compound represented by the formula (I) is 0.01 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic acid ester polymer, the adhesion between the pressure-sensitive adhesive layer and the transparent electrode is improved. When the content is 10 parts by mass or less, bleeding out of the silane compound represented by the formula (I) from the pressure-sensitive adhesive layer tends to be suppressed.

<Antistatic agent>
The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include known ones, and an ionic antistatic agent is preferable. Examples of the cation component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of the organic cation include a pyridinium cation, an imidazolium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation. Examples of the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. The anionic component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, but an anionic component containing a fluorine atom is preferred from the viewpoint of excellent antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion (PF ₆ ⁻ ), bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ], bis (fluorosulfonyl) imide anion [(FSO ₂ ) ₂ N ⁻ ] anion.
An ionic antistatic agent that is solid at room temperature is preferable in that the antistatic performance of the pressure-sensitive adhesive composition is excellent over time.

<Other ingredients>
The pressure-sensitive adhesive composition may further contain a crosslinking catalyst, a weather resistance stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, and the like.

<Transparent electrode>
Examples of the transparent electrode include those composed of tin oxide, indium oxide, zinc oxide, gallium oxide, aluminum oxide, and mixtures thereof. In terms of conductivity and visible light transmittance, indium oxide (ITO) to which tin oxide is added is preferable.
When the transparent electrode is disposed on the surface of the glass substrate of the liquid crystal cell, the transparent electrode may be disposed on the entire surface of the glass substrate or may be disposed on a part thereof. When a transparent electrode is disposed on a part of the glass substrate, a part of the pressure-sensitive adhesive layer is in direct contact with the glass substrate, but the pressure-sensitive adhesive layer in the optical laminate of the present invention has an adhesive property with glass. The liquid crystal display device provided with the optical laminate of the present invention is also excellent in durability.
<Optical laminate>
The optical layered body of the present invention can be prepared by, for example, forming an adhesive layer on an optical film and then bonding the adhesive layer and a transparent electrode.
As a method for forming the pressure-sensitive adhesive layer on the optical film, for example, the pressure-sensitive adhesive composition is applied on a suitable substrate and dried to form a pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive of the formed pressure-sensitive adhesive sheet Examples include a method of laminating the optical film on the layer surface, and then peeling the substrate, and a method of applying the pressure-sensitive adhesive composition on the optical film.
As the substrate, a plastic film is suitable, and specifically, a release film that has been subjected to a mold release treatment can be mentioned. Examples of the release film include those obtained by performing release treatment such as silicone treatment on one surface of a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate and the like. For temporary protection of the pressure-sensitive adhesive layer surface of the pressure-sensitive adhesive sheet, a release film may be attached to the pressure-sensitive adhesive layer surface.

  After sticking the optical film on which the pressure-sensitive adhesive layer is formed and the transparent electrode to prepare an optical laminate, if there is any defect, the optical film is peeled from the transparent electrode, and another pressure-sensitive adhesive layer A so-called rework operation may be required to re-attach the formed optical film to the transparent electrode, but in the rework operation, the pressure-sensitive adhesive layer is peeled off from the transparent electrode together with the optical film, Almost no adhesive residue is generated. Therefore, the optical film on which the pressure-sensitive adhesive layer is formed can be easily re-attached to the transparent electrode after peeling, and the optical laminate of the present invention is excellent in terms of reworkability.

The cross-sectional schematic diagram of an example of the layer structure of the optical laminated body of this invention was shown in FIGS.
An optical laminate 1A shown in FIG. 1 has a configuration in which a polarizing plate 5, which is one of optical films, an adhesive layer 10, and a transparent electrode 20 are laminated in this order, and the transparent electrode 20 of the optical laminate 1A. In addition, a liquid crystal cell 50 is further laminated. As for the polarizing plate 5, the protective film 3 which has the surface treatment layer 4 on the single side | surface of the polarizing film 2 is affixed on the surface on the opposite side to the surface treatment layer 4 of the protective film 3. FIG.

An optical laminate 1B shown in FIG. 2 has a configuration in which a composite polarizing plate 7, which is one of optical films, an adhesive layer 10, and a transparent electrode 20 are laminated in this order, and the transparent electrode of the optical laminate 1B is provided. 20, a liquid crystal cell 50 is further laminated. In the composite polarizing plate 7, the protective film 3 having the surface treatment layer 4 is attached to one surface of the polarizing film 2 on the surface opposite to the surface treatment layer 4 of the protective film 3, and the other surface is attached. The retardation film 6 is stuck.
A preferable example of the retardation film 6 is a quarter wavelength plate, and the absorption axis of the polarizing film 2 and the slow axis of the retardation film 6 that is a quarter wavelength plate intersect at about 45 °. However, depending on the characteristics of the liquid crystal cell 50, the crossing angle can be shifted from 45 ° to some extent.
In addition, for the purpose of retardation compensation and viewing angle compensation of the liquid crystal cell 50, a retardation film having an appropriate retardation according to the characteristics of the liquid crystal cell 50 can be used as the retardation film 6. In this case, it is common to arrange the polarizing film 2 and the retardation film 6 so that the absorption axis and the slow axis of the retardation film 6 are substantially orthogonal or substantially parallel.

  An optical laminate 1C shown in FIG. 3 has a configuration in which a composite polarizing plate 9, which is one of optical films, an adhesive layer 10, and a transparent electrode 20 are laminated in this order, and the transparent electrode of the optical laminate 1C is provided. 20, a liquid crystal cell 50 is further laminated. In the composite polarizing plate 9, the protective film 3 having the surface treatment layer 4 is attached to one surface of the polarizing film 2 on the surface opposite to the surface treatment layer 4 of the protective film 3, and the other surface is attached. The retardation film 6 is adhered, and the second retardation film 6 ′ is laminated on the other surface of the retardation film 6 via the interlayer adhesive layer 8. The interlayer pressure-sensitive adhesive layer 8 is usually formed of a general acrylic pressure-sensitive adhesive.

  In these examples, the adhesion between the protective film 3 and the polarizing film 2 and the adhesion between the polarizing film 2 and the retardation film 6 are performed by, for example, an aqueous adhesive or an ultraviolet curable adhesive.

  The optical laminated body shown in FIGS. 1 to 3 is an example assuming the arrangement on the viewing side of the liquid crystal cell 50, but the optical laminated body of the present invention is disposed on the back side (backlight side) of the liquid crystal cell. It can also be arranged. When arrange | positioning the optical laminated body of this invention in the back surface side of the liquid crystal cell 50, it replaces with the protective film 3 which has the surface treatment layer 4, for example, and sticks the protective film which does not have a surface treatment layer to the polarizing film 2. Except for the above, the configuration may be the same as in FIGS. 1 to 3, and on the back side of a known liquid crystal cell such as a brightness enhancement film, a light collecting film, a diffusion film, etc. You may provide the film arrange | positioned.

  The optical layered body of the present invention can be suitably used for a liquid crystal display device. Such liquid crystal display devices include various mobile devices such as smartphones and tablet terminals; notebook computers, desktop computers, personal computers including PDAs (Personal Digital Assistants), etc .; televisions; in-vehicle displays; electronic dictionaries; digital cameras; It is suitable as a liquid crystal display device for video cameras; electronic desk calculators;

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, the parts and% representing the amount used and the content are based on mass unless otherwise specified.

A weight average molecular weight is the value (standard polystyrene conversion) measured on the following conditions with the gel permeation chromatography apparatus.
Column: Four “TSKgel XL” (manufactured by Tosoh Corporation) and one “Shodex GPC KF-802” (manufactured by Showa Denko KK) connected in series Eluent: Tetrahydrofuran Sample concentration: 5 mg / mL
Sample introduction amount: 100 μL
Temperature: 40 ° C
Flow rate: 1 mL / min

[Synthesis of (meth) acrylic acid ester polymer]
A (meth) acrylic acid ester polymer was synthesized using the following monomers.
M1: butyl acrylate M2: methyl acrylate M3: 2-phenoxyethyl acrylate M4: 2-hydroxyethyl acrylate M5: acrylic acid

[Polymerization Example 1]
A reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer was charged with a solution obtained by mixing 81.8 parts of ethyl acetate with a monomer having the composition shown in “Polymerization Example 1” in Table 1. It is. After the air in the reaction vessel was replaced with nitrogen gas, the internal temperature was set to 60 ° C. Thereafter, a solution in which 0.14 part of azobisisobutyronitrile was dissolved in 10 parts of ethyl acetate was added. After maintaining at the same temperature for 1 hour, while maintaining the internal temperature at 54 ° C. to 56 ° C., ethyl acetate was added into the reaction vessel at an addition rate of 17.3 parts / hr so that the concentration of the polymer was approximately 35%. Added continuously. The internal temperature is maintained at 54 ° C. to 56 ° C. until 12 hours have elapsed from the start of the addition of ethyl acetate, and then ethyl acetate is added to adjust the polymer concentration to 20%. A solution was obtained. The weight average molecular weight (Mw) of the obtained polymer was 1.39 million, and Mw / Mn was 5.32. This is polymer A.

[Polymerization Example 2]
A polymer was obtained in the same manner as in Polymerization Example 1 except that the composition of the monomer used in Polymerization Example 1 was changed to the composition described in “Polymerization Example 2” in Table 1. Mw of the obtained polymer was 1.48 million and Mw / Mn was 5.20. This is polymer B.

[Polymerization Example 3]
A polymer was obtained in the same manner as in Polymerization Example 1 except that the composition of the monomer used in Polymerization Example 1 was changed to the composition described in “Polymerization Example 3” in Table 1. The obtained polymer had Mw of 14.1 million and Mw / Mn of 4.71. This is polymer C.

[Preparation of pressure-sensitive adhesive composition]
The used crosslinking agent, silane compound and antistatic agent are as follows.
<Crosslinking agent>
D1: Takenate (registered trademark) D-110N [ethyl acetate solution of trimethylolpropane adduct of xylylene diisocyanate (solid content concentration 75%)] Obtained from Mitsui Chemicals, Inc.
<Silane compound>
S1: Bis (triethoxysilyl) ethane S2: Bis (trimethoxysilyl) hexane S3: Bis (triethoxysilyl) octane S4: Glycidoxypropyltrimethoxysilane S5: Glycidoxypropyltriethoxysilane S6: Glycidoxy Propyldimethoxymethylsilane S7: Glycidoxypropyldiethoxymethylsilane S8: Glycidoxyoctyltrimethoxysilane S9: X-12-981 [epoxy group-containing silicone oligomer]
S10: X-12-987 [Thioester group-containing silane coupling agent]
S11: X-12-989 [urea group-containing silane coupling agent]
S12: X-12-1016M [thiourea group-containing silane coupling agent]
S13: Tris (trimethoxysilyl) isocyanurate S14: Tris (triethoxysilyl) isocyanurate S15: Bis (trimethoxysilylpropyl) amine S16: X-41-1818 [mercapto group-containing silicone oligomer]
S17: X-41-1810 [mercapto group-containing silicone oligomer]
S18: X-41-1059A [epoxy group-containing silicone oligomer]
S19: X-41-1056 [epoxy group-containing silicone oligomer]
S20: X-24-9451 [triazine thiol group-containing silicone oligomer]
All the silane compounds were obtained from Shin-Etsu Chemical Co., Ltd.

<Antistatic agent>
AS1: N-octyl-4-methylpyridinium hexafluorophosphate (melting point: 44 ° C.)

[Examples 1-6 and Comparative Examples 1-20]
(A) Preparation of pressure-sensitive adhesive composition Table 2 shows the ethyl acetate solutions (polymer concentration: 20%) of the polymers obtained in Polymerization Examples 1, 2, and 3 with respect to 100 parts of the solid content of the solution. Thus, after mix | blending a crosslinking agent, a silane compound, and an antistatic agent, ethyl acetate was added so that solid content concentration might be 14%, and the adhesive composition was obtained.

(B) Production of pressure-sensitive adhesive sheet The pressure-sensitive adhesive composition prepared in (a) above was subjected to a release treatment, and a polyethylene terephthalate film [trade name “PLR-382051” obtained from Lintec Co., Ltd., hereinafter, a separator Was applied to the release-treated surface of the mold by an applicator so that the thickness after drying was 20 μm, and then dried at 100 ° C. for 1 minute to obtain an adhesive sheet.

(C) Preparation of polarizing plate on which pressure-sensitive adhesive layer was formed Polyvinyl alcohol film having an average polymerization degree of about 2400, a saponification degree of 99.9 mol%, and a thickness of 60 μm [trade name “Kuraray Vinylon VF- manufactured by Kuraray Co., Ltd.” PE # 6000 ″] is immersed in pure water at 37 ° C., and is then added to an aqueous solution containing iodine and potassium iodide (iodine / potassium iodide / water (weight ratio) = 0.04 / 1.5 / 100). It was immersed at 30 ° C. Then, it was immersed at 56.5 ° C. in an aqueous solution containing potassium iodide and boric acid (potassium iodide / boric acid / water (weight ratio) = 12 / 3.6 / 100). 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 23 μm in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.
A transparent protective film (trade name “KC2UA” of Konica Minolta Opto Co., Ltd.) made of a 25 μm thick triacetyl cellulose film is placed on both sides of the obtained polarizing film with an adhesive made of an aqueous solution of a polyvinyl alcohol resin. To form a polarizing plate. Next, the surface (adhesive layer surface) opposite to the separator of the pressure-sensitive adhesive sheet prepared in (b) above was bonded to one side of the polarizing plate with a laminator, and then the temperature was 23 ° C. and the relative humidity was 65%. Curing was performed for 7 days to obtain a polarizing plate on which an adhesive layer was formed.

(D) Production of optical layered product The separator is peeled off from the polarizing plate on which the pressure-sensitive adhesive layer obtained in (c) is formed, and the pressure-sensitive adhesive surface is placed on the ITO surface of the glass substrate for a liquid crystal cell having an ITO layer on one side. The optical laminate was obtained by pasting. As a glass substrate having an ITO layer, a non-alkali glass manufactured by Corning [trade name “Eagle XG”] having an ITO layer of 30 nm formed by ITO deposition was used.

[Durability evaluation of optical laminates]
The produced optical laminate was stored for 750 hours under dry conditions at a temperature of 85 ° C. The optical layered body after storage was visually observed for appearance changes such as lifting, peeling and foaming of the pressure-sensitive adhesive layer, and evaluated according to the following evaluation criteria. The results are shown in Table 3.
<Durability evaluation criteria>
(Double-circle): It is an optical laminated body which does not have appearance changes, such as a float, peeling, and foaming, and has very favorable durability.
◯: An optical laminate having good durability with hardly any change in appearance such as floating, peeling or foaming.
(Triangle | delta): The external appearance changes, such as a float, peeling, and foaming, are somewhat conspicuous, and the durability of an optical laminated body is unsatisfactory.
X: Appearance changes such as floating, peeling and foaming are remarkably observed, and the durability of the optical laminate is extremely poor.

[Evaluation of reworkability of optical laminates]
The polarizing plate on which the pressure-sensitive adhesive layer prepared in (c) was formed was cut into a test piece having a size of 25 mm × 150 mm. The separator was peeled off from the test piece, and the pressure-sensitive adhesive surface was attached to a glass substrate with an ITO layer by a sticking device [trade name “Lamipacker” manufactured by Fuji Plastics Co., Ltd.]. The test piece on which the obtained glass substrate with an ITO layer was affixed (an optical laminate on which the glass substrate was affixed) was placed in an autoclave at a temperature of 50 ° C. and a pressure of 5 kg / cm ² (490.3 kPa) for 20 minutes. Pressurized. Next, after heat-treating at 70 ° C. for 2 hours, it was stored in an oven at 50 ° C. for 48 hours. Further, in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, the polarizing plate was removed from the test piece together with the adhesive layer by 300 mm. The film peeled in the direction of 180 ° at a speed of / min. The surface state of the ITO layer was observed and evaluated according to the following criteria. The results are shown in Table 3.

<Evaluation criteria for reworkability>
(Double-circle): It is an optical laminated body which has very good rework property without cloudiness etc. being recognized on the surface of an ITO layer at all.
A: The optical layered body has good reworkability with almost no clouding or the like observed on the surface of the ITO layer.
(Triangle | delta): Cloudiness etc. are recognized on the surface of an ITO layer, and the rework property of an optical laminated body is unsatisfactory.
X: The remainder of an adhesive layer is recognized on the surface of an ITO layer, and the rework property of an optical laminated body is very bad.

[Evaluation of ITO corrosivity of optical laminates]
The surface resistance (surface resistance value before the test) of the ITO layer of the glass substrate with the ITO layer was measured with a low resistivity meter (trade name “Loresta-AX” manufactured by Mitsubishi Chemical Analytech Co., Ltd.). Next, the polarizing plate on which the pressure-sensitive adhesive layer prepared in the above (c) is formed is cut into a test piece having a size of 20 mm × 40 mm, and attached to the ITO layer side of the glass substrate via the pressure-sensitive adhesive layer. did. The obtained optical laminate was stored in an oven at a temperature of 60 ° C. and a relative humidity of 90% for 72 hours, and then peeled between the ITO layer and the adhesive layer in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. did. The surface resistance (surface resistance value after test) of the ITO layer after peeling was measured. The rate of change in resistance before and after the test was calculated by the following formula and evaluated according to the following criteria. The smaller the rate of resistance change, the lower the ITO corrosivity. The results are shown in Table 3.
Resistance change rate (%) = [(surface resistance value after test) − (surface resistance value before test)] / [surface resistance value before test] × 100

<Evaluation criteria for ITO corrosivity>
◯: An optical laminate having a resistance change rate of less than 30% and good ITO corrosivity.
(Triangle | delta): Resistance change rate is 30% or more and less than 100%, and ITO corrosivity of an optical laminated body is unsatisfactory.
X: The resistance change rate is 100% or more, and the ITO corrosiveness of the optical laminate is extremely poor.

  The optical layered body of the present invention is suitable for a liquid crystal display device in the durability test because the pressure-sensitive adhesive layer does not float or peel off, has excellent durability, and does not corrode the transparent electrode.

1A, 1B, 1C Optical laminate 2 Polarizing film 3 Protective film 4 Surface treatment layer 5 Polarizing plate 6 Retardation film 7, 9 Composite polarizing plate 8 Interlayer adhesive 10 Adhesive layer 20 Transparent electrode 50 Liquid crystal cell

Claims (12)

An optical film, an adhesive layer and a transparent electrode are laminated in this order, and the adhesive layer comprises a (meth) acrylic acid ester polymer, a crosslinking agent, and a formula (I):

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the alkanediyl group and the alicyclic hydrocarbon group. —CH ₂ — may be replaced by —O— or —CO—, R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are And each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)
The content of structural units derived from the monomer having a carboxyl group in the (meth) acrylic acid ester polymer is 100% of all structural units of the (meth) acrylic acid ester polymer. The optical laminated body formed from the adhesive composition which is less than 2 mass parts with respect to a mass part. The silane compound represented by formula (I) is represented by formula (II):

(Wherein R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ each have the same meaning as described above, R ⁷ represents an alkyl group having 1 to 5 carbon atoms, and m represents 1 to 20) Represents an integer.)
The optical laminate according to claim 1, which is a silane compound represented by the formula:   The optical laminate according to claim 2, wherein m is an integer of 4 to 20 in formula (II).   The content of the silane compound represented by the formula (I) in the pressure-sensitive adhesive composition is 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer. 3 is an optical laminate.   The optical laminate according to any one of claims 1 to 4, wherein the (meth) acrylic acid ester polymer includes a structural unit derived from a monomer having a hydroxy group.   The optical laminate according to any one of claims 1 to 5, wherein the (meth) acrylic acid ester polymer includes a structural unit derived from a monomer having an aromatic group.   The (meth) acrylic acid ester polymer is a structural unit derived from a (meth) acrylic acid ester having a homopolymer glass transition temperature of 0 ° C. or higher, and (meth) acrylic acid having a homopolymer glass transition temperature of 0 ° C. or lower. The optical laminate according to claim 1, comprising a structural unit derived from an ester.   The optical layered product according to any one of claims 1 to 7, wherein the (meth) acrylic acid ester polymer has a weight average molecular weight of 500,000 to 2,500,000.   The optical laminate according to any one of claims 1 to 8, wherein the crosslinking agent is an isocyanate compound.   The optical laminate according to claim 1, wherein the pressure-sensitive adhesive composition further contains an antistatic agent.   The liquid crystal display device containing the optical laminated body in any one of Claims 1-10. (Meth) acrylate polymer, crosslinking agent and formula (I):

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the alkanediyl group and the alicyclic hydrocarbon group. —CH ₂ — may be replaced by —O— or —CO—, R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are And each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)
The content of the structural unit derived from the carboxyl group-containing monomer in the (meth) acrylic acid ester polymer is 100 parts by mass of the total structural unit of the (meth) acrylic acid ester polymer. On the other hand, the adhesive composition for transparent electrodes which is less than 2 mass parts.

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