JP6920825B2 - Adhesive composition - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive composition useful as an optical member used in a liquid crystal display device or the like, a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition, an optical film with a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive. The present invention relates to an optical laminate including a layered optical film.

An optical film represented by a polarizing plate formed by laminating and laminating a transparent resin film on one side or both sides of a polarizer 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 is often used by being bonded to another member (for example, a liquid crystal cell in a liquid crystal display device) via an adhesive layer (see Patent Document 1). Therefore, as an optical film, an optical film with an adhesive layer in which an adhesive layer is previously provided on one surface thereof is known.

Japanese Unexamined Patent Publication No. 2010-229321

In recent years, liquid crystal display devices have been developed for mobile device applications such as smartphones and tablet terminals and for in-vehicle devices such as car navigation systems. In such an application, since there is a possibility of being exposed to a harsher environment as compared with the conventional indoor TV application, improvement of the durability of the device is an issue.

Similarly, the optical film with an adhesive layer that constitutes a liquid crystal display device or the like is also required to have durability. That is, the adhesive layer incorporated in the liquid crystal display device or the like may be placed in a high temperature or high temperature and high humidity environment, or may be placed in an environment where high temperature and low temperature are repeated, but the adhesive layer is attached. The optical film is required to be able to suppress problems such as floating and peeling at the interface between the pressure-sensitive adhesive layer and the optical member to which the pressure-sensitive adhesive layer is attached, and foaming of the pressure-sensitive adhesive layer even in these environments. It is also required that the optical characteristics do not deteriorate. In particular, when the optical film is a polarizing plate, the pressure-sensitive adhesive layer is required to have higher durability than a general optical film due to strong shrinkage stress in a high temperature environment. Due to the increasing demand for improving the durability of the liquid crystal display device described above, the durability required for the pressure-sensitive adhesive layer has recently become extremely strict.

Therefore, an object of the present invention is a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer exhibiting good durability even under such harsh durability conditions, a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition, and the pressure-sensitive adhesive. It is an object of the present invention to provide an optical film with a pressure-sensitive adhesive layer containing a layer, and an optical laminate containing the optical film with a pressure-sensitive adhesive layer.

（式中、ｎは１〜４の整数を示し、Ａ^１は水素原子又はアルキル基を示し、Ｘ^１は置換基を有していてもよいメチレン基を示し、ｎが２以上のとき、前記置換基は同一又は異なっていてもよい）
で表されるヒドロキシ基含有（メタ）アクリレート（ｂ１）由来の構成単位、下記式（ｂ２）

（式中、ｍは５以上の整数を示し、Ａ^２は水素原子又はアルキル基を示し、Ｘ^２は置換基を有していてもよいメチレン基を示し、前記置換基は同一又は異なっていてもよい）
で表されるヒドロキシ基含有（メタ）アクリレート（ｂ２）由来の構成単位、及びアセトアセチル基含有（メタ）アクリレート（ｂ３）由来の構成単位から選択される少なくとも１種を含む、［１］〜［６］のいずれかに記載の粘着剤組成物。
［８］（メタ）アクリル系樹脂（Ｂ）は、ヒドロキシ基含有（メタ）アクリレート（ｂ１）由来の構成単位と、ヒドロキシ基含有（メタ）アクリレート（ｂ２）由来の構成単位又はアセトアセチル基含有（メタ）アクリレート（ｂ３）由来の構成単位とを含む、［７］に記載の粘着剤組成物。
［９］ヒドロキシ基含有（メタ）アクリレート（ｂ１）由来の構成単位と、ヒドロキシ基含有（メタ）アクリレート（ｂ２）由来の構成単位又はアセトアセチル基含有（メタ）アクリレート（ｂ３）由来の構成単位との質量比（ｂ１）／（ｂ２又はｂ３）は１４〜１である、［８］に記載の粘着剤組成物。
［１０］（メタ）アクリル系樹脂（Ｂ）は、ホモポリマーのガラス転移温度が０℃未満のアルキルアクリレート（ｂ４）由来の構成単位と、ホモポリマーのガラス転移温度が０℃以上のアルキルアクリレート（ｂ５）由来の構成単位とを含む、［５］〜［９］のいずれかに記載の粘着剤組成物。
［１１］ホモポリマーのガラス転移温度が０℃未満のアルキルアクリレート（ｂ４）由来の構成単位と、ホモポリマーのガラス転移温度が０℃以上のアルキルアクリレート（ｂ５）由来の構成単位との質量比（ｂ４）／（ｂ５）は０．１〜１０である、［１０］に記載の粘着剤組成物。
［１２］（メタ）アクリル系樹脂（Ｂ）に含まれるカルボキシル基含有（メタ）アクリレート由来の構成単位の割合は、（メタ）アクリル系樹脂（Ｂ）を構成する全構成単位１００質量部に対して１．０質量部以下である、［５］〜［１１］のいずれかに記載の粘着剤組成物。
［１３］架橋剤（Ｃ）はイソシアネート系化合物である、［５］〜［１２］のいずれかに記載の粘着剤組成物。
［１４］架橋剤（Ｃ）の割合は、（メタ）アクリル系樹脂（Ｂ）１００質量部に対して、０．０１〜１０質量部である、［５］〜［１３］のいずれかに記載の粘着剤組成物。
［１５］シラン化合物（Ｄ）は、下記式（ｄ１）

（式中、Ｂは、炭素数１〜２０のアルカンジイル基又は炭素数３〜２０の二価の脂環式炭化水素基を示し、前記アルカンジイル基及び前記脂環式炭化水素基を構成する−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置換されてもよく、Ｒ^７は炭素数１〜５のアルキル基を示し、Ｒ^８、Ｒ^９、Ｒ^１０、Ｒ^１１及びＲ^１２はそれぞれ独立して、炭素数１〜５のアルキル基又は炭素数１〜５のアルコキシ基を示す）
で表されるシラン化合物である、［５］〜［１４］のいずれかに記載の粘着剤組成物。
［１６］シラン化合物（Ｄ）の割合は、（メタ）アクリル系樹脂（Ｂ）１００質量部に対して、０．０１〜１０質量部である、［５］〜［１５］のいずれかに記載の粘着剤組成物。
［１７］光重合開始剤及びその分解物を実質的に含有しない、［１］〜［１６］のいずれかに記載の粘着剤組成物。
［１８］［１］〜［１７］のいずれかに記載の粘着剤組成物からなる粘着剤層。
［１９］前記粘着剤層のゲル分率が７０〜９０％である、［１８］に記載の粘着剤層。
［２０］光学フィルムと、該光学フィルムの少なくとも一方の面に積層された粘着剤層とを含む粘着剤層付光学フィルムであって、該粘着剤層は、［１８］又は［１９］に記載の粘着剤層である、粘着剤層付光学フィルム。
［２１］［２０］に記載の粘着剤層付光学フィルムと、該粘着剤層付光学フィルムの粘着剤層側に積層された基材とを含む、光学積層体。 The present inventor has completed the present invention as a result of diligent studies to solve the above problems.
That is, the present invention includes the following.
[1] A pressure-sensitive adhesive composition containing a silane compound (A) containing a Si—Si bond.
[2] The pressure-sensitive adhesive composition according to [1], wherein the silane compound (A) is a silane compound having a weight average molecular weight of 300 or more.
[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the silane compound (A) is a polysilane compound having a crosslinked structure in the molecule.
[4] The pressure-sensitive adhesive composition according to any one of [1] to [3], wherein the silane compound (A) is a compound having a hydroxy group.
[5] The adhesion according to any one of [1] to [4], which further contains a (meth) acrylic resin (B), a cross-linking agent (C), and a silane compound (D) containing no Si—Si bond. Agent composition.
[6] The pressure-sensitive adhesive composition according to any one of [1] to [5], wherein the (meth) acrylic resin (B) has a weight average molecular weight of 1 million or more in terms of polystyrene.
[7]
The (meth) acrylic resin (B) has the following formula (b1).

(In the formula, n represents an integer of 1 to 4, A ¹ represents a hydrogen atom or an alkyl group, X ¹ represents a methylene group which may have a substituent, and when n is 2 or more, the above. Substituents may be the same or different)
A structural unit derived from the hydroxy group-containing (meth) acrylate (b1) represented by the following formula (b2).

(In the formula, m represents an integer of 5 or more, A ² represents a hydrogen atom or an alkyl group, X ² represents a methylene group which may have a substituent, and the substituents are the same or different. May be good)
[1]-[ 6] The pressure-sensitive adhesive composition according to any one of.
[8] The (meth) acrylic resin (B) contains a hydroxy group-containing (meth) acrylate (b1) -derived structural unit and a hydroxy group-containing (meth) acrylate (b2) -derived structural unit or an acetoacetyl group-containing (meth) acrylic resin (B). The pressure-sensitive adhesive composition according to [7], which comprises a structural unit derived from a meta) acrylate (b3).
[9] A structural unit derived from a hydroxy group-containing (meth) acrylate (b1), a structural unit derived from a hydroxy group-containing (meth) acrylate (b2), or a structural unit derived from an acetoacetyl group-containing (meth) acrylate (b3). The pressure-sensitive adhesive composition according to [8], wherein the mass ratio (b1) / (b2 or b3) of the above is 14 to 1.
[10] The (meth) acrylic resin (B) is a structural unit derived from an alkyl acrylate (b4) having a homopolymer glass transition temperature of less than 0 ° C. and an alkyl acrylate having a homopolymer glass transition temperature of 0 ° C. or higher. The pressure-sensitive adhesive composition according to any one of [5] to [9], which comprises a structural unit derived from b5).
[11] Mass ratio of a structural unit derived from an alkyl acrylate (b4) having a glass transition temperature of less than 0 ° C. of a homopolymer and a structural unit derived from an alkyl acrylate (b5) having a glass transition temperature of a homopolymer having a glass transition temperature of 0 ° C. or higher ( The pressure-sensitive adhesive composition according to [10], wherein b4) / (b5) is 0.1 to 10.
[12] The proportion of the structural unit derived from the carboxyl group-containing (meth) acrylate contained in the (meth) acrylic resin (B) is 100 parts by mass of all the structural units constituting the (meth) acrylic resin (B). The pressure-sensitive adhesive composition according to any one of [5] to [11], which is 1.0 part by mass or less.
[13] The pressure-sensitive adhesive composition according to any one of [5] to [12], wherein the cross-linking agent (C) is an isocyanate compound.
[14] The ratio of the cross-linking agent (C) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin (B), as described in any of [5] to [13]. Adhesive composition.
[15] The silane compound (D) has the following formula (d1).

(In the formula, B 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 7} represents an alkyl group having 1 to 5 carbon ^{atoms, R 8, R 9, R} 10, R 11 and ^{R 12} are each Independently, it indicates an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms).
The pressure-sensitive adhesive composition according to any one of [5] to [14], which is a silane compound represented by.
[16] The ratio of the silane compound (D) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin (B), as described in any of [5] to [15]. Adhesive composition.
[17] The pressure-sensitive adhesive composition according to any one of [1] to [16], which does not substantially contain a photopolymerization initiator and a decomposition product thereof.
[18] A pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to any one of [1] to [17].
[19] The pressure-sensitive adhesive layer according to [18], wherein the gel content of the pressure-sensitive adhesive layer is 70 to 90%.
[20] An optical film with an adhesive layer including an optical film and an adhesive layer laminated on at least one surface of the optical film, wherein the adhesive layer is described in [18] or [19]. An optical film with an adhesive layer, which is an adhesive layer of.
[21] An optical laminate comprising the optical film with an adhesive layer according to [20] and a base material laminated on the adhesive layer side of the optical film with an adhesive layer.

The pressure-sensitive adhesive composition of the present invention can form a pressure-sensitive adhesive layer having good durability even under harsh durability conditions.

It is schematic cross-sectional view which shows an example of the optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition which concerns on this invention. FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of the polarizing plate. FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate. FIG. 4 is a schematic cross-sectional view showing an example of an optical laminate including an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention. FIG. 5 is a schematic cross-sectional view showing another example of an optical laminate containing an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention. FIG. 6 is a schematic cross-sectional view showing still another example of an optical laminate containing an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention. FIG. 7 is a schematic cross-sectional view showing another example of an optical laminate containing an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention. FIG. 8 is a schematic cross-sectional view showing still another example of an optical laminate containing an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention.

[1] Adhesive Composition The adhesive composition of the present invention contains a silane compound (A) containing a Si—Si bond.

[1-1] Silane compound (A) containing a Si—Si bond
The silane compound (A) is a silane compound containing a Si (silicon atom) -Si (silicon atom) bond. From the viewpoint of the durability of the pressure-sensitive adhesive layer, the silane compound (A) is preferably a polysilane compound containing two or more Si—Si bonds. The Si-Si bond may be in the main chain or the side chain, and usually has a Si-Si bond in the main chain. The structural form of the silane compound (A) is not particularly limited, and may be, for example, a linear chain, a branched chain, a cyclic structure, a crosslinked structure or the like. Among these, a polysilane compound having a branched chain structure, particularly a crosslinked structure in the molecule, is preferable, and when the polysilane compound is contained in the pressure-sensitive adhesive composition, the durability of the pressure-sensitive adhesive layer can be effectively improved. More preferably, it is a network-like (or network-like) polysilane compound, and when the polysilane compound is contained in the pressure-sensitive adhesive composition, the durability of the pressure-sensitive adhesive layer can be further improved. Here, the network-like (or network-like) means a structure in which a plurality of silicon atoms are bonded to each other and connected in a three-dimensional network. The number of networks in the network structure is not particularly limited, but a structure having two or more networks is usually referred to as a network (or network). When a substituent is bonded to the silicon atom contained in the silane compound (A), the silicon atom and a part of the substituents may form a network structure.

（式中、Ｒ^１〜Ｒ^６はそれぞれ独立して水素原子、アルキル基、シクロアルキル基、アリール基、アラルキル基、アルコキシ基、ヒドロキシ基、アミノ基、置換アミノ基を示す） In a preferred embodiment, the silane compound (A) is a polysilane compound having at least one structural unit represented by the following formulas (a1) to (a4).

(In the formula, R ^{1 to} R ⁶ independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxy group, an amino group, and a substituted amino group).

^{In R 1 to} R ⁶ of the formulas (a1) to (a4), examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group and the like. The linear or branched C _1-10 alkyl group is preferably a linear or branched C _1-6 alkyl group, and more preferably a linear or branched C _1-4. It is an alkyl group. _{Examples of the cycloalkyl group include a C 5-8} cycloalkyl group such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group include a phenyl group, alkylphenyl group (methylphenyl (tolyl) group, dimethylphenyl (xylyl) group, etc.), biphenyl groups include C _6-12 aryl groups such as naphthyl group, preferably a C _{6- It is a 10} aryl group. Examples of the aralkyl group include a benzyl group and a C _7-14 aralkyl group such as a phenethyl group. _{Examples of the alkoxy group include a linear or branched C 1-10} alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, and a t-butoxy group. It is preferably a linear or branched C _1-6 alkoxy group, and is preferably a linear or branched C _1-4 alkoxy group. Examples of the substituted amino group include the N-mono or di-substituted amino group substituted with the alkyl group, cycloalkyl group, aryl group, aralkyl group, acyl group and the like. Among these substituents, an alkyl group, an aryl group, an alkoxy group, a hydroxy group and the like are preferable from the viewpoint of improving the durability of the pressure-sensitive adhesive composition. Further, if the silane compound (A) contains a polar group (particularly a hydroxy group) such as an alkoxy group or a hydroxy group, a crosslinked structure optimal for exhibiting good durability can be formed, so that a highly durable adhesive layer can be formed. Obtainable.

The structural units (a1) to (a4) constituting the silane compound (A) can be appropriately selected according to the shape of the silane compound (A), and the silane compound (A) may be used alone or in combination of two or more types (a1). ~ (A4) may be included. For example, when the structure of the silane compound (A) is linear, the silane compound (A) contains a structural unit represented by the above formula (a2) and has a structure in which silicon atoms are linearly bonded. In the case of a cyclic structure, the silane compound (A) contains three or more structural units (a2) and has a structure in which silicon atoms are cyclically bonded. In the case of a network (or network), the silane compound (A) contains a structural unit (a3) and / or (a4), and has a structure in which silicon atoms are bonded in a network.

The number of repeating units of the structural units (a1) to (a4) can be appropriately selected according to the shape and molecular weight of the polysilane compound, and the total number of repeating units of the structural units (a1) to (a4) is preferably 2 to 200. , More preferably 3 to 150, still more preferably 5 to 120, and particularly preferably 7 to 100. When the number of repeating units of each structural unit is 2 or more, ^{the types of substituents (R 1 to} R ⁶ ) may be the same or different among the structural units.

In a preferred embodiment, the silane compound (A) is a network-like polysilane compound mainly composed of the structural unit (a3) from the viewpoint of the durability of the pressure-sensitive adhesive layer. In this silane compound (A), the ratio of the structural unit (a3) is preferably 70 mol% or more, more preferably 80 mol% or more, based on the total number of moles of all the structural units contained in the silane compound (A). , More preferably 90 mol% or more. When the ratio of the structural unit (a3) is not more than the lower limit value, the silane compound (A) can form a three-dimensional network structure which is advantageous for durability.

In a more preferred embodiment, the silane compound (A) has a network having a structural unit (a3) and a structural unit (a1) and / or a structural unit (a2), more preferably a structural unit (a3) and a structural unit (a2). It is a polysilane compound. In this aspect, the pressure-sensitive adhesive layer can exhibit good durability even in a high temperature environment.

In the polysilane compound having the structural unit (a3) and the structural unit (a2), the molar ratio (a3) / (a2) of the structural unit (a3) and the structural unit (a2) is preferably 1 to 20, more preferably. Is 3 to 15. When the molar ratio is in this range, the durability in a high temperature environment can be further improved.

In the network polysilane compound having a structural unit (a3) and a structural unit (a2), from the viewpoint of improving durability, R ⁴ and R ⁵ of the structural unit (a2) are preferably alkyl groups (preferably C _{1), respectively. -4} Alkyl group), aryl group (preferably C _6-10 aryl group) and hydroxy group, and R ⁶ of the structural unit (a3) is preferably an alkyl group (preferably C _{1-), respectively. 4} Alkyl group), aryl group (preferably C _6-10 aryl group) and hydroxy group. The molar ratio (aryl group / alkyl group) of the aryl group to the alkyl group contained in the network polysilane compound is preferably 1 to 15, more preferably 1.5 to 12, and even more preferably 2 to 11. When the molar ratio is in the above range, the durability of the pressure-sensitive adhesive layer can be further improved.

As a typical example of the silane compound (A) (preferably the network-like silane compound (A)), a polysilane compound having a structural unit (a3) in which ^{R 6} is an alkyl group, for example, a structural unit in which ^{R 6 is a methyl group (} A polysilane compound having a structural unit (a3) in which a3) and R ⁶ are ethyl groups; a polysilane compound having a structural unit (a3) in which R ⁶ is an aryl group (particularly a phenyl group); R ⁶ is an alkyl group (particularly methyl). polysilane compound structural unit (a3) and R ⁶ is a group) has a structural unit is an aryl group (especially phenyl group) (a3); R ⁴ is an alkyl group (especially methyl) and R ⁵ is an aryl group (especially and the structural unit is a phenyl group) (a2), a polysilane compound wherein R ⁶ including the structural unit (a3) and an aryl group (especially phenyl group); R ⁴ is an alkyl group (especially methyl) and R ⁵ is aryl A polysilane compound having a structural unit (a2) that is a group (particularly a phenyl group) and a structural unit (a3) in which R ⁶ is an alkyl group (particularly a methyl group) or an aryl group (particularly a phenyl group); R ⁴ and R ^{A polysilane compound having a structural unit (a2) in which 5} is an alkyl group (particularly a methyl group) and a structural unit (a3) in which R ⁶ is an alkyl group (particularly a methyl group) or an aryl group (particularly a phenyl group); A ^{structural unit (a2) in which R 4} and R ⁵ are aryl groups (particularly phenyl groups), respectively, and a structural unit (a 3) in which R ⁶ is an alkyl group (particularly methyl group) or an aryl group (particularly phenyl group). Polysilane compound having; In the above-mentioned network-like silane compound (A), ^{a silane compound in which a part of R 4 to} R ⁶ is substituted with a hydroxy group and the like can be mentioned. Among these, from the viewpoint of the durability of the pressure-sensitive adhesive layer, a polysilane compound having the above-exemplified structural unit (a2) and structural unit (a3) is preferable. These silane compounds (A) can be used alone or in combination of two or more.

The lower limit of the weight average molecular weight (Mw) of the silane compound (A) is preferably 300 or more, more preferably 500 or more, still more preferably 700 or more, particularly preferably 700 or more, in terms of standard polystyrene by gel permeation chromatography GPC. It is 1000 or more. The upper limit of the weight average molecular weight (Mw) of the silane compound (A) is preferably 100,000 or less, more preferably 50,000 or less, still more preferably 30,000 or less, and particularly preferably 20,000 or less. Further, the weight average molecular weight (Mw) of the silane compound (A) may be any combination of the above upper limit value and the above lower limit value, preferably 300 to 100,000, more preferably 500 to 50,000, still more preferably 700. It is ~ 30,000, particularly preferably 1000 ~ 20000. When Mw is in the above range, good durability can be exhibited even in a high temperature environment (for example, an environment of 100 ° C. or higher). The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is usually 1.0 to 10.0, preferably 1.0 to 5.0, and more preferably 1. It is 0 to 2.0.

Examples of the method for producing the silane compound (A) include a conventional method, a method of dehalogenating condensation polymerization of halosilanes corresponding to each constituent unit in the presence of an alkali metal, and the like. Examples of commercially available products of the silane compound (A) include Ogsol SI-10-10, SI-10-20, SI-20-10, and SI-30-10 manufactured by Osaka Gas Chemical Co., Ltd. Be done.

The ratio of the silane compound (A) is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, still more preferably 0, based on 100% by mass of the total solid content of the pressure-sensitive adhesive composition. .5 to 3% by mass, particularly preferably 0.7 to 2% by mass. When the ratio of the silane compound (A) is in the above range, it is advantageous for improving the durability of the pressure-sensitive adhesive layer.

The proportion of the silane compound (A) is such that when the pressure-sensitive adhesive composition contains a polymer (for example, the (meth) acrylic resin (B) described later), the polymer (for example, the (meth) acrylic resin (B) described later)). With respect to 100 parts by mass, preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, still more preferably 0.5 to 3 parts by mass, and particularly preferably 0.7 to 2 parts by mass. be. When the ratio of the silane compound (A) is in the above range, it is advantageous for improving the durability of the pressure-sensitive adhesive layer.

Since the pressure-sensitive adhesive composition of the present invention contains the silane compound (A) containing a Si—Si bond, the pressure-sensitive adhesive composed of the pressure-sensitive adhesive composition even in a high-temperature environment (for example, a high-temperature environment of 100 ° C. or higher). The durability of the layer can be improved, and peeling (or floating), foaming and cohesive failure of the interface can be effectively suppressed. It is presumed that this is because the silane compound (A) can improve the cohesive force of the components contained in the pressure-sensitive adhesive composition (for example, the polymer such as the (meth) acrylic resin (B) described later).

In the present specification, the term "durability" means, for example, in a high temperature environment, a high temperature and high humidity environment, an environment in which high temperature and low temperature are repeated, and the like at the interface between the pressure-sensitive adhesive layer and an optical member adjacent thereto. It refers to a property that can suppress floating and peeling (sometimes referred to as peeling resistance) and a property that can suppress defects such as foaming of the adhesive layer (sometimes referred to as foam resistance). Further, in the present specification, the coagulation fracture resistance refers to a property capable of suppressing coagulation failure (or tearing) of the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive composition of the present invention can further contain a (meth) acrylic resin (B), a cross-linking agent (C), and a silane compound (D) that does not contain a Si—Si bond.

[1-2] (Meta) Acrylic resin (B)
The (meth) acrylic resin (B) contains 100% by mass of all the constituent units constituting the (meth) acrylic resin (B), preferably 50 constituent units derived from the (meth) acrylic monomer. It is a polymer or copolymer containing by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more. In the present specification, "(meth) acrylic" means acrylic or methacrylic, and similarly, "(meth) acrylate" and "(meth) acryloyl" are also referred to as acrylate or methacrylate, acryloyl or methacrylic, respectively. means.

The (meth) acrylic resin (B) is, for example, a constituent unit derived from a polar group-containing (meth) acrylate, a constituent unit derived from a (meth) acrylamide-based monomer, a constituent unit derived from a styrene-based monomer, and a vinyl-based constituent unit. Monomer-derived structural unit, monomer-derived structural unit having a plurality of (meth) acryloyl groups in the molecule, aryl acrylate-derived structural unit, alkyl acrylate-derived structural unit, substituent-containing alkyl acrylate-derived composition It may include a unit or the like. These structural units can be used alone or in combination of two or more.

Examples of the polar group-containing (meth) acrylate include a hydroxy group-containing (meth) acrylate, a heterocyclic group-containing (meth) acrylate such as an epoxy group, a substituted or unsubstituted amino group-containing (meth) acrylate, and a carboxyl group-containing (meth). Examples thereof include acrylates and acetacetyl group-containing (meth) acrylates.

（式中、ｎは１〜４の整数を示し、Ａ^１は水素原子又はアルキル基を示し、Ｘ^１は置換基を有していてもよいメチレン基を示し、ｎが２以上のとき、前記置換基は同一又は異なっていてもよい）

（式中、ｍは５以上の整数を示し、Ａ^２は水素原子又はアルキル基を示し、Ｘ^２は置換基を有していてもよいメチレン基を示し、前記置換基は同一又は異なっていてもよい） The hydroxy group-containing (meth) acrylate preferably includes a hydroxy group-containing (meth) acrylate represented by the following formula (b1) or (b2).

(In the formula, n represents an integer of 1 to 4, A ¹ represents a hydrogen atom or an alkyl group, X ¹ represents a methylene group which may have a substituent, and when n is 2 or more, the above. Substituents may be the same or different)

(In the formula, m represents an integer of 5 or more, A ² represents a hydrogen atom or an alkyl group, X ² represents a methylene group which may have a substituent, and the substituents are the same or different. May be good)

In formulas (b1) and (b2), X ¹ and X ² represent methylene groups that may have substituents. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom) and an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, s-butyl group, t- _{C 1-10} alkyl groups such as butyl group, pentyl group, hexyl group, preferably C _1-6 alkyl group, more preferably C _1-3 alkyl group, cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.) _{C 5-8} cycloalkyl group), an aryl group [for example, an alkyl phenyl group (tolyl group, xylyl group), _{C 6-12} aryl groups such as phenyl] _{C 7 - 14,} such as an aralkyl group (e.g. benzyl Aralkyl group), alkoxy group (eg, C _1-4 alkoxy group such as methoxy group, ethoxy group), polyoxyalkylene group (eg, dioxyethylene group), cycloalkoxy group (eg, cyclohexyloxy group, etc.) _5-10 cycloalkyloxy group), an aryloxy group (e.g., _{C 6-12} aryloxy groups such as phenoxy group), aralkyloxy group (e.g., _{C 7 - 14} aralkyloxy group such as benzyloxy group), an alkylthio group _{(For example, C 1-4} alkylthio group such as methylthio group, ethylthio group), cycloalkylthio group (for example, C _5-8 cycloalkylthio group such as cyclohexylthio group), arylthio group (for example, C such as thiophenoxy group). _6-12 arylthio group), aralkylthio group (e.g., _{C 7 - 14} aralkylthio group) such as benzylthio group, an acyl group (e.g., _{C 2-7} acyl group), a nitro group such as an acetyl group, a cyano group Can be mentioned. Of these, a halogen atom, an alkyl group, an alkoxy group, and an aryloxy group are preferable, and an alkyl group is more preferable.

A ¹ and A ² represent a hydrogen atom or an alkyl group, respectively, and the alkyl group is ^{an alkyl group exemplified by X 1} and X ² , preferably a methyl group.
In the formula (b1), n represents an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2. Further, in the equation (b2), m represents an integer of 5 or more. m is usually an integer of 5 to 20, preferably 5 to 15, more preferably an integer of 5 to 11, still more preferably an integer of 5 to 9, and even more preferably 5 to 7. It is an integer of, and is particularly preferably 5.

Specific examples of the hydroxy group-containing (meth) acrylate (b1) include 1-hydroxymethyl (meth) acrylate, 1-hydroxyethyl (meth) acrylate, 1-hydroxyheptyl (meth) acrylate, and (meth) acrylic. 1-Hydroxybutyl acid, 1-hydroxypentyl (meth) acrylate, 1-hydroxy C _1-8 alkyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate 2-Hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, 2-hydroxyhexyl (meth) acrylate, etc. 2-hydroxy C _2-9 alkyl (meth) acrylate; (meth) acrylic (Meta) such as 3-hydroxypropyl acid, 3-hydroxybutyl (meth) acrylate, 3-hydroxypentyl (meth) acrylate, 3-hydroxyhexyl (meth) acrylate, 3-hydroxyheptyl (meth) acrylate, etc. 3-Hydroxy C _3-10 alkyl acrylate; 4-hydroxybutyl (meth) acrylate, 4-hydroxypentyl (meth) acrylate, 4-hydroxyhexyl (meth) acrylate, 4-hydroxyheptyl (meth) acrylate , (Meta) 4-hydroxyoctyl acrylate, etc. (meth) 4-hydroxy C _4-11 alkyl acrylate; 2-chloro-2-hydroxypropyl (meth) acrylate, 3-chloro-2 (meth) acrylate -Hydroxypropyl, 2-hydroxy-3-phenoxypropyl (meth) acrylate and the like can be mentioned. Of these, from the viewpoint of durability, a hydroxy group-containing (meth) acrylate having n of 2 such as 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. A hydroxy group-containing (meth) acrylate having n of 3, such as 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 3-hydroxypentyl (meth) acrylate, is preferable. In particular, a hydroxy group-containing (meth) acrylate having n of 2 is preferable, and 2-hydroxyethyl (meth) acrylate is more preferable.

Specific examples of the hydroxy group-containing (meth) acrylate (b2) include 5-hydroxypentyl (meth) acrylate, 5-hydroxyhexyl (meth) acrylate, 5-hydroxyheptyl (meth) acrylate, and (meth) acrylic. acid 5-hydroxy-octyl, (meth) acrylic acid 5-hydroxy-nonyl (meth) acrylic acid 5-hydroxy _{C 5-12} alkyl; (meth) acrylic acid 6-hydroxyhexyl, (meth) acrylic acid 6-hydroxy-heptyl , (Meta) Acrylic Acid 6-Hydroxyoctyl, (Meta) Acrylic Acid 6-Hydroxynonyl, (Meta) Acrylic Acid 6-Hydroxydecyl, etc. (Meta) Acrylic Acid 6-Hydroxy C _6-13 Alkyl; (Meta) Acrylic (Meta) such as 7-hydroxyheptyl acid, 7-hydroxyoctyl (meth) acrylate, 7-hydroxynonyl (meth) acrylate, 7-hydroxydecyl (meth) acrylate, 7-hydroxyundecyl (meth) acrylate. ) Acrylic acid 7-hydroxy C _7-14 alkyl; (meth) acrylic acid 8-hydroxyoctyl, (meth) acrylic acid 8-hydroxynonyl, (meth) acrylic acid 8-hydroxydecyl, (meth) acrylic acid 8-hydroxy _{(Meta) Acrylic Acid 8-Hydroxy C 8-15} Alkyl, such as Undecyl, (Meta) Acrylic Acid 8-Hydroxydodecyl; (Meta) Acrylic Acid 9-Hydroxynonyl, (Meta) Acrylic Acid 9-Hydroxydecyl, (Meta) ) 9-Hydroxyundecyl acrylate, 9-hydroxydodecyl (meth) acrylate, 9-hydroxytridecyl (meth) acrylate and the like 9-hydroxy C _9-16 alkyl (meth) acrylate; (meth) acrylate (Meta) acrylics such as 10-hydroxydecyl, 10-hydroxyundecyl (meth) acrylate, 10-hydroxydodecyl (meth) acrylate, 10-hydroxytridecyl acrylate, 10-hydroxytetradecyl (meth) acrylate. Acid 10-Hydroxy C _10-17 Alkyl; (meth) acrylate 11-hydroxyundecyl, (meth) acrylate 11-hydroxydodecyl, (meth) acrylate 11-hydroxytridecyl, (meth) acrylate 11-hydroxy _{(Meta) Acrylic Acid 10-Hydroxy C 11-18} Alkyl such as Tetradecyl, (Meta) Acrylic Acid 11-Hydroxypentadecyl; (Meta) Acrylic Acid 12-Hydroxy Dodecyl, 12-hydroxytridecyl (meth) acrylate, 12-hydroxytetradecyl (meth) acrylate, etc. 12-hydroxy C _12-19 alkyl (meth) acrylate; 13-hydroxypenta (meth) acrylate decyl, (meth) acrylic acid 13-hydroxy-tetradecyl, (meth) acrylic acid 13-hydroxy-pentadecyl (meth) acrylic acid 13-hydroxy _{C 13-20} alkyl; (meth) acrylic acid 14-hydroxy-tetradecyl, _{14-HydroxyC 14-21} alkyl (meth) acrylate, such as 14-hydroxypentadecyl (meth) acrylate; 15-hydroxypentadecyl (meth) acrylate, 15-hydroxyheptadecyl (meth) acrylate, etc. Meta) Acrylic acid 15-hydroxy C _15-22 alkyl and the like can be mentioned. Of these, from the viewpoint of durability, 5-hydroxypentyl (meth) acrylate, 5-hydroxyhexyl (meth) acrylate, 5-hydroxyheptyl (meth) acrylate, 5-hydroxyoctyl (meth) acrylate, A hydroxy group-containing (meth) acrylic rate having an m of 5, such as 5-hydroxynonyl (meth) acrylate, is preferable, and 5-hydroxypentyl (meth) acrylate is more preferable.

The acetoacetyl group-containing (meth) acrylate (b3) may contain a substituent other than the acetoacetyl group, and examples of the substituent include a cyano group and the like. _{Specific examples of the acetoacetyl group-containing (meth) acrylate (b3) include acetoacetoxy C 2-10} alkyl (acetoacetoxy C 2-10 alkyl) such as acetoacetoxyethyl (meth) acrylate, acetoacetoxypropyl (meth) acrylate, and acetoacetoxybutyl (meth) acrylate. Meta) Acrylate; _Examples thereof include cyanoacetoacetoxy C 2-10 alkyl (meth) acrylate such as 2-cyanoacetoacetoxyethyl (meth) acrylate. Of these, from the viewpoint of the durability of the pressure-sensitive adhesive layer, acetoacetoxyethyl (meth) acrylate, acetoacetoxypropyl (meth) acrylate, and acetoacetoxybutyl (meth) acrylate are preferable, and 2-acetacetoxyethyl (meth) acrylate is preferable. ) It is more preferable that it is acrylate. These acetoacetyl group-containing (meth) acrylates (b3) can be used alone or in combination of two or more.

When the (meth) acrylic resin (B) contains a structural unit derived from a polar group-containing (meth) acrylate, even when the pressure-sensitive adhesive composition is applied to a transparent electrode such as ITO (tin-doped indium oxide). It can show good durability in a high temperature environment. This is because when such a (meth) acrylic resin (B) is contained in the pressure-sensitive adhesive composition, it has an optimum cross-linking structure and cross-linking density for exhibiting good durability due to the influence of highly reactive polar groups. It is presumed that this is because the pressure-sensitive adhesive layer can be formed.

In a preferred embodiment, the (meth) acrylic resin (B) is a structural unit derived from a hydroxy group-containing (meth) acrylate represented by the formula (b1), and a hydroxy group-containing (meth) represented by the formula (b2). ) Containing at least one selected from acrylate-derived structural units and acetoacetyl group-containing (meth) acrylate (b3) -derived structural units. In this aspect, the durability of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be further improved. In a particularly preferred embodiment, the (meth) acrylic resin (B) comprises a hydroxy group-containing (meth) acrylate (b1) -derived structural unit and a hydroxy group-containing (meth) acrylate (b2) -derived structural unit or an acetoacetyl group. Contains structural units derived from the contained (meth) acrylate (b3). In this embodiment, the (meth) acrylic resin has a hydroxyalkyl group having a different carbon chain length (n and m) or a hydroxyalkyl group and an acetoacetyl group in the side chain, which is advantageous for forming an optimum crosslinked structure. Therefore, it is possible to more effectively suppress peeling (or floating) of the interface, coagulation fracture and foaming in a high temperature environment, and it is possible to further improve the durability of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. ..

The ratio of the structural units derived from the hydroxy group-containing (meth) acrylate represented by the formula (b1) is preferably 1.5 to 10 with respect to 100 parts by mass of all the structural units constituting the (meth) acrylic resin. It is by mass, more preferably 2 to 8 parts by mass.
The proportion of the constituent units derived from the hydroxy group-containing (meth) acrylate or the acetacetyl group-containing (meth) acrylate represented by the formula (b2) is 100 parts by mass of all the constituent units constituting the (meth) acrylic resin. On the other hand, it is preferably 0.1 to 8 parts by mass, and more preferably 0.25 to 3 parts by mass.
A structural unit derived from a hydroxy group-containing (meth) acrylate represented by the formula (b1) and a structural unit derived from a hydroxy group-containing (meth) acrylate represented by the formula (b2) or an acetoacetyl group-containing (meth) acrylate (meth). The ratio (mass ratio) with the constituent unit derived from b3) is not particularly limited as long as it is in the above range, but is preferably (b1) / (b2 or b3) = 14 to 1, more preferably 13 to 1, and even more preferably. Is 11 to 1, especially 9 to 1. Within the above range, the durability of the pressure-sensitive adhesive layer can be further improved.

Examples of the heterocyclic group-containing (meth) acrylate include acryloylmorpholine, vinylcaprolactone, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, and 3,4-epoxycyclohexylmethyl. Examples thereof include (meth) acrylate, glycidyl (meth) acrylate, and 2,5-dihydrofuran. Examples of the substituted or unsubstituted amino group-containing (meth) acrylate include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylate. Examples of the carboxyl group-containing (meth) acrylate include (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and carboxyalkyl (meth) acrylate (for example, carboxyethyl (meth) acrylate and carboxypentyl (meth)). Acrylate) and the like. These (meth) acrylates can be used alone or in combination of two or more. From the viewpoint of preventing a decrease in the peelability of the separate film that can be laminated on the pressure-sensitive adhesive layer, it is preferable that the constituent unit derived from the monomer having an amino group is substantially not contained. The term "substantially free" means that the amount is less than 1.0 part by mass with respect to 100 parts by mass of all the constituent units constituting the (meth) acrylic resin (B).

When the pressure-sensitive adhesive composition contains a structural unit derived from a carboxyl group-containing (meth) acrylate, it exhibits good durability, but it is considered that it increases the corrosion of transparent electrodes such as ITO. The pressure-sensitive adhesive composition of the present invention can further improve durability by containing only a small amount of a structural unit derived from a carboxyl group-containing (meth) acrylate to the extent that a transparent electrode such as ITO is not corroded. Therefore, by incorporating a small amount of a structural unit derived from a carboxyl group-containing (meth) acrylate into the pressure-sensitive adhesive composition of the present invention, it is possible to achieve both durability and transparency electrode corrosion resistance (ITO corrosion resistance). It is possible.

The ratio of the structural unit derived from the carboxyl group-containing (meth) acrylate is 1.0 part by mass or less with respect to 100 parts by mass of all the structural units constituting the (meth) acrylic resin. The upper limit of the proportion of the structural unit derived from the carboxyl group-containing (meth) acrylate is preferably 0.5 parts by mass, more preferably 0.3 parts by mass, still more preferably 0.2 parts by mass, and particularly preferably 0.15 parts. It is a mass part. The lower limit of the proportion of the structural unit derived from the carboxyl group-containing (meth) acrylate is preferably 0 parts by mass, more preferably 0.001 parts by mass, still more preferably 0.005 parts by mass, and particularly preferably 0.01 parts by mass. In particular, it is 0.05 parts by mass. The proportion of the structural unit derived from the carboxyl group-containing (meth) acrylate may be any combination of the upper limit value and the lower limit value, for example, 0 to 1 part by mass, preferably 0 to 0.8 part by mass, more preferably. Is 0.001 to 0.5 parts by mass, more preferably 0.005 to 0.3 parts by mass, particularly preferably 0.01 to 0.2 parts by mass, and particularly preferably 0.05 to 0.15 parts by mass. be. When the proportion of the structural unit derived from the carboxyl group-containing (meth) acrylate is not more than the upper limit value, the corrosion of the transparent electrode can be suppressed, and when it is more than the lower limit value, the durability can be improved.

Examples of the (meth) acrylamide-based monomer include N-methylol acrylamide, N- (2-hydroxyethyl) acrylamide, N- (3-hydroxypropyl) acrylamide, N- (4-hydroxybutyl) acrylamide, and N- (5). -Hydroxypentyl) acrylamide, N- (6-hydroxyhexyl) acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-isopropylacrylamide, N- (3-dimethylaminopropyl) acrylamide, N- (1) , 1-Dimethyl-3-oxobutyl) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl] acrylamide, 2-acrylloylamino-2-methyl-1-propanesulfonic acid, N- (methoxymethyl) Acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (1-methylethoxymethyl) acrylamide, N- (1-methylpropoxymethyl) acrylamide, N- (2-methylpropoxymethyl) acrylamide [Also known as: N- (isobutoxymethyl) acrylamide], N- (butoxymethyl) acrylamide, N- (1,1-dimethylethoxymethyl) acrylamide, N- (2-methoxyethyl) acrylamide, N- (2-ethoxy) Ethyl) acrylamide, N- (2-propoxyethyl) acrylamide, N- [2- (1-methylethoxy) ethyl] acrylamide, N- [2- (1-methylpropoxy) ethyl] acrylamide, N- [2-( 2-Methylpropoxy) ethyl] acrylamide [also known as N- (2-isobutoxyethyl) acrylamide], N- (2-butoxyethyl) acrylamide, N- [2- (1,1-dimethylethoxy) ethyl] acrylamide, etc. Can be mentioned. The durability of the pressure-sensitive adhesive layer can be further improved by containing a structural unit derived from a (meth) acrylamide-based monomer. In particular, among these, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, and N- (2-methylpropoxymethyl) acrylamide. Is preferable.

The ratio of the constituent units derived from the (meth) acrylamide-based monomer is preferably 5 parts by mass or less with respect to 100 parts by mass of all the constituent units constituting the (meth) acrylic resin. The upper limit of the ratio of the constituent units derived from the (meth) acrylamide-based monomer is preferably 3 parts by mass, more preferably 2 parts by mass, and further preferably 1 part by mass. The lower limit of the proportion of the constituent units derived from the (meth) acrylamide-based monomer is preferably 0 parts by mass, more preferably 0.001 parts by mass, still more preferably 0.01 parts by mass, and particularly preferably 0.1 parts by mass. It is a department. The ratio of the constituent units derived from the (meth) acrylamide-based monomer may be any combination of these upper limit values and lower limit values, for example, 0 to 5 parts by mass, preferably 0.001 to 3 parts by mass, and more. It is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 1 part by mass. When the ratio of the constituent units derived from the (meth) acrylamide-based monomer is within the above range, the durability of the pressure-sensitive adhesive layer can be further improved. Further, when it is not more than the above upper limit value, the storage stability of the (meth) acrylic resin (B) can be improved.

Examples of styrene-based monomers include styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene and other alkylstyrenes; fluorostyrene, Examples thereof include halogenated styrene such as chlorostyrene, bromostyrene, dibromostyrene and iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; divinylbenzene and the like.

Examples of the vinyl-based monomer include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride and the like. Vinylidene halide; nitrogen-containing aromatic vinyl such as vinylpyridine, vinylpyrrolidone and vinylcarbazole; conjugated diene monomers such as butadiene, isoprene and chloroprene; unsaturated nitriles such as acrylonitrile and methacrylonitrile may be mentioned.

Examples of the monomer having a plurality of (meth) acryloyl groups in the molecule include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di ( Two (meth) acryloyl groups in molecules such as meta) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate. Monomer having; Examples thereof include a monomer having three (meth) acryloyl groups in the molecule such as trimethyl propantri (meth) acrylate.

Examples of the aryl acrylate include _C6-12 aryl acrylate such as phenyl acrylate and naphthyl acrylate.

Examples of the alkyl acrylate include an alkyl acrylate (b4) in which the glass transition temperature (Tg) of the homopolymer is less than 0 ° C., an alkyl acrylate (b5) in which the Tg of the homopolymer is 0 ° C. or higher.

Alkyl acrylates (b4) having a homopolymer glass transition temperature (Tg) of less than 0 ° C. include ethyl acrylates, n- and i-propyl acrylates, n- and i-butyl acrylates, n-pentyl acrylates, n- and i. Alkyl groups such as −hexyl acrylate, n-heptyl acrylate, n- and i-octyl acrylate, 2-ethylhexyl acrylate, n- and i-nonyl acrylate, n- and i-decyl acrylate, n-dodecyl acrylate. Examples thereof include linear or branched alkyl acrylates having about 2 to 12 carbon atoms. The alkyl acrylate (b4) may be an alkyl acrylate (cycloalkyl acrylate) having an alicyclic structure, but from the viewpoint of flexibility and adhesiveness to an optical film, it may be linear or branched with 2 to 10 carbon atoms. A chain alkyl acrylate is preferable, a linear or branched alkyl acrylate having 3 to 8 carbon atoms is more preferable, and a linear or branched alkyl acrylate having 4 to 6 carbon atoms is used. Is more preferable, and n-butylalkyl acrylate is particularly preferable. When n-butylalkyl acrylate is used, the followability can be improved, which is advantageous for, for example, peeling resistance. These alkyl acrylates (b4) can be used alone or in combination of two or more.

Examples of the alkyl acrylate (b5) in which the Tg of the homopolymer is 0 ° C. or higher include methyl acrylate, cycloalkyl acrylate (for example, cyclohexyl acrylate, isobolonyl acrylate), stearyl acrylate, t-butyl acrylate, and the like. It is particularly preferable to have. When methyl acrylate is used, the strength can be increased, which is advantageous for, for example, cohesive failure. These alkyl acrylates (b5) can be used alone or in combination of two or more. For the Tg of the homopolymer of the alkyl acrylate, reference values such as POLYMER HANDBOOK (Wiley-Interscience) can be referred to.

From the viewpoint of improving the durability of the pressure-sensitive adhesive layer, the (meth) acrylic resin (B) contains a structural unit derived from an alkyl acrylate (b4) having a homopolymer glass transition temperature of less than 0 ° C. and a homopolymer glass transition temperature. It is preferable to contain a structural unit derived from an alkyl acrylate (b5) having a temperature of 0 ° C. or higher. When an alkyl acrylate having a homopolymer Tg of less than 0 ° C. and an alkyl acrylate having a homopolymer Tg of 0 ° C. or higher are used in combination, both coagulation fracture resistance, foaming resistance and peeling resistance can be achieved, and an optical film (for example, polarized light) can be obtained. Durability against dimensional changes of the plate) can be improved.

The ratio of the constituent units derived from alkyl acrylate in the (meth) acrylic resin (B) is 100 mass by mass of all the constituent units constituting the (meth) acrylic resin (B) from the viewpoint of durability and reworkability of the pressure-sensitive adhesive layer. For example, 40 parts by mass or more (for example, 50 to 98 parts by mass), preferably 60 parts by mass or more (for example, 70 to 95 parts by mass), and more preferably 70 parts by mass or more (for example, 80 parts by mass). ~ 90 parts by mass).

Mass ratio (b4) / (b5) of a structural unit derived from an alkyl acrylate (b4) having a glass transition temperature of less than 0 ° C. and a structural unit derived from an alkyl acrylate (b5) having a glass transition temperature of 0 ° C. or higher. Is preferably 0.1 to 10, more preferably 0.2 to 5, and even more preferably 0.3 to 3.5. Within the above range, durability can be further improved. The larger the proportion of the structural unit derived from the alkyl acrylate (b4) having a glass transition temperature of less than 0 ° C., the better the followability. The larger the proportion of the constituent units derived from the alkyl acrylate (b5) having a glass transition temperature of 0 ° C. or higher, the better the coagulation fracture resistance.

Examples of the substituent-containing alkyl acrylate include an alkyl acrylate in which the hydrogen atom of the alkyl group in the alkyl acrylate is substituted with a substituent. Examples of the substituent include an aryl group (phenyl group and the like), an aryloxy group (phenoxy group), an alkoxy group (for example, a methoxy group, an ethoxy group and the like) and the like. Examples of the substituent-containing alkyl acrylate include alkoxyalkyl acrylate (for example, 2-methoxyethyl acrylate, ethoxymethyl acrylate, etc.), arylalkyl acrylate (for example, benzyl acrylate, etc.), aryloxyalkyl acrylate (for example, phenoxyethyl acrylate, etc.), and aryloxypoly. Examples thereof include alkylene glycol monoacrylate and polyalkylene glycol monoacrylate. These alkyl acrylates can be used alone or in combination of two or more. By containing an alkyl acrylate containing an aromatic ring such as an aryl group, a benzyl group, or an aryloxy group, it is possible to improve the white spotting of the polarizing plate during the durability test. Further, by containing an alkoxy group, an aryloxy group, or the like, the antistatic property when an antistatic agent is added to the pressure-sensitive adhesive layer can be improved. The alkylene group of the aryloxypolyalkylene glycol monoacrylate and the polyalkylene glycol monoacrylate may be, for example, a C _1-6 alkylene group (preferably an ethylene group or the like) such as a methylene group, an ethylene group or a propylene group, and may be an oxy. The repeating unit of the alkylene group is, for example, 1 to 7, preferably 1 to 5 (particularly 1 to 2), from the viewpoint of the balance between the durability and the antistatic property of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. Specific examples thereof include phenoxydi to hepta C _1-3 alkylene glycol acrylate such as phenoxydiethylene glycol acrylate, and di to hepta C _1-3 alkylene monoacrylate such as diethylene glycol monoacrylate. As the substituent-containing alkyl acrylate used in the present invention, phenoxyethyl acrylate and phenoxydiethylene glycol acrylate are particularly preferable from the viewpoint of the balance between durability, white spot resistance and antistatic property.

The ratio of the structural unit derived from the substituent-containing alkyl acrylate is, for example, 0 to 30 parts by mass, preferably 1 to 25 parts by mass, based on 100 parts by mass of all the structural units constituting the (meth) acrylic resin (B). It is more preferably 3 to 20 parts by mass, still more preferably 5 to 15 parts by mass.

The weight average molecular weight (Mw) of the (meth) acrylic resin (B) in terms of standard polystyrene by gel permeation chromatography GPC is preferably 1 million or more in order to further enhance the durability of the pressure-sensitive adhesive layer. .. The lower limit of Mw is more preferably 1.1 million, still more preferably 1.2 million, and particularly preferably 1.25 million. The upper limit of Mw is not particularly limited, but is preferably 2.5 million, more preferably 2.2 million, from the viewpoint of coatability when the pressure-sensitive adhesive composition is processed into, for example, a sheet (coating on a base material). , More preferably 2 million. Mw may be any combination of these upper and lower limit values, and may be, for example, 1 to 2.5 million, more preferably 1.1 million to 2.2 million, and even more preferably 125 to 2 million. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is usually 2 to 10, preferably 3 to 8, and more preferably 3 to 6.

Further, (meth) acrylic resin (B) preferably has a single peak in Mw of 1.0 × ¹⁰ 3 ~2.5 × ^{10 6} range on discharge curve in GPC. The use of the (meth) acrylic resin (B) having the number of peaks of 1 is advantageous for improving the durability of the pressure-sensitive adhesive layer.

The resulting "having a single peak" in the range of the discharge curve, which means that with only one maximum in Mw1.0 × 10 ³ ~2.5 × 10 ⁶ range. In the present specification, the peak has an S / N ratio of 30 or more in the GPC emission curve. The number of peaks on the GPC emission curve and Mw and Mn of the (meth) acrylic resin (B) can be determined by the GPC measurement conditions described in the section of Examples.

When the (meth) acrylic resin (B) is dissolved in ethyl acetate to prepare a solution having a concentration of 20% by mass, the viscosity at 25 ° C. is preferably 20 Pa · s or less, preferably 0.1 to 15 Pa · s. Is more preferable. A viscosity in this range is advantageous from the viewpoint of coatability when the pressure-sensitive adhesive composition is applied to the substrate. The viscosity can be measured with a Brookfield viscometer.

The glass transition temperature (Tg) of the (meth) acrylic resin (B) is, for example, -60 to 10 ° C, preferably -50 to 5 ° C, more preferably -40 to -5 ° C, and particularly -40 to -10 ° C. It may be. When Tg is not more than the upper limit value, it is advantageous to improve the wettability of the pressure-sensitive adhesive layer with respect to the adherend base material, and when it is not more than the lower limit value, it is advantageous to improve the durability of the pressure-sensitive adhesive layer. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

The (meth) acrylic resin (B) can be produced by a known method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, or an emulsion polymerization method, and the solution polymerization method is particularly preferable. As a solution polymerization method, for example, a monomer and an organic solvent are mixed, a thermal polymerization initiator is added under a nitrogen atmosphere, and a temperature condition of 40 to 90 ° C., preferably about 50 to 80 ° C. is 3 to 15 A method of stirring for about an hour can be mentioned. In order to control the reaction, a monomer or a thermal polymerization initiator may be added continuously or intermittently during the polymerization. The monomer and the heat initiator may be in a state of being added to an organic solvent.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator and the like are used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone. Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), and 2 , 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis (2-methylpropionate) ), 2,2'-Azobis (2-hydroxymethylpropionitrile) and other azo compounds; lauryl peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, Organic peroxides such as diisopropylperoxydicarbonate, dipropylperoxydicarbonate, t-butylperoxyneodecanoate, t-butylperoxypivalate, (3,5,5-trimethylhexanoyl) peroxide ; Examples include inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. In addition, a redox-based initiator in which a peroxide and a reducing agent are used in combination can also be used.

The ratio of the polymerization initiator is about 0.001 to 5 parts by mass with respect to 100 parts by mass of the total amount of the monomers constituting the (meth) acrylic resin. For the polymerization of the (meth) acrylic resin, a polymerization method using active energy rays (for example, ultraviolet rays) may be used.

Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone. Can be mentioned.

[1-3] Crosslinking agent (C)
The pressure-sensitive adhesive composition can contain a cross-linking agent (C). The cross-linking agent (C) reacts with a polar group (for example, a hydroxy group, an acetoacetyl group, an amino group, a carboxyl group, etc.) in the (meth) acrylic resin (B). The cross-linking agent (C) forms a cross-linked structure with a (meth) acrylic resin or the like, and forms a cross-linked structure advantageous in durability and reworkability.

Examples of the cross-linking agent (C) include conventional cross-linking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.), and particularly for the pot life of the pressure-sensitive adhesive composition and the pressure-sensitive adhesive layer. From the viewpoint of durability, cross-linking rate and the like, an isocyanate compound is preferable.

As the isocyanate-based compound, a compound having at least two isocyanato groups (-NCO) in the molecule is preferable, and for example, an aliphatic isocyanate-based compound (for example, hexamethylene diisocyanate) and an alicyclic isocyanate-based compound (for example, isophorone diisocyanate) are preferable. , Hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate-based compounds (for example, tolylene diisocyanate, xylylene diisocyanate diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.) and the like. The cross-linking agent (C) is an adduct (adduct) of the isocyanate compound made of a polyhydric alcohol compound [for example, an adduct made of glycerol, trimethylolpropane, etc.], an isocyanurate, a burette-type compound, a polyether polyol, or a polyester. It may be a derivative such as a urethane prepolymer type isocyanate compound which has been subjected to an addition reaction with a polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, or the like. The cross-linking agent (C) can be used alone or in combination of two or more. Of these, typically aromatic isocyanate compounds (eg, tolylene diisocyanate, xylylene diisocyanate), aliphatic isocyanate compounds (eg, hexamethylene diisocyanate) or their polyhydric alcohol compounds (eg, glycerol, trimethylolpropane). ), Or isocyanurates. If the cross-linking agent (C) is an aromatic isocyanate compound and / or an adduct of these polyhydric alcohol compounds or an isocyanurate compound, it is advantageous for forming an optimum cross-linking density (or cross-linking structure). The durability of the adhesive layer can be improved. In particular, an adduct made of a tolylene diisocyanate compound and / or a polyhydric alcohol compound thereof can improve durability even when, for example, a pressure-sensitive adhesive layer is applied to a transparent electrode.

The ratio of the cross-linking agent (C) is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 with respect to 100 parts by mass of the (meth) acrylic resin (B). It is ~ 3 parts by mass, more preferably 0.1 to 2 parts by mass, particularly preferably 0.2 to 1 part by mass, and particularly preferably 0.25 to 0.8 parts by mass. If it is not more than the upper limit value, it is advantageous to improve the followability (or peeling resistance), and if it is more than the lower limit value, it is advantageous to improve the foaming resistance and the rework resistance.

[1-4] Silane compound (D) containing no Si—Si bond
The pressure-sensitive adhesive composition can contain a silane compound (D) that does not contain a Si—Si bond. By containing the silane compound (D) in the pressure-sensitive adhesive composition, the adhesion (or adhesiveness) between the pressure-sensitive adhesive layer and the metal layer, the transparent electrode, the glass substrate and the like can be improved. The silane compound (D) may be any silane compound capable of binding to a polar group (for example, hydroxy group, acetoacetyl group, amino group, carboxyl group, etc.) of the (meth) acrylic resin (B), and is preferably a molecule. It is a silane compound having at least one alkoxy group in it. _{Examples of the alkoxy group include C 1-6} alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an s-butoxy group, and a t-butoxy group. From the viewpoint of adhesion, it is preferably a methoxy group and an ethoxy group.

Examples of the silane compound (D) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glyci. Sidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3- Examples thereof include methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 1,3-bis (3'-trimethoxypropyl) urea.

Further, the silane compound (D) may be a silicone oligomer type compound, and when the silicone oligomer is represented by a combination of monomers, for example, 3-mercaptopropyldi or trimethoxysilane-tetramethoxysilane oligomer, 3 -Mercaptoalkyl group-containing oligomers such as mercaptomethyldi or trimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyldi or triethoxysilane-tetramethoxysilane oligomer, 3-mercaptomethyldi or triethoxysilane-tetraethoxysilane oligomer Examples thereof include oligomers in which the mercaptoalkyl group of the mercaptoalkyl group-containing oligomer is replaced with another substituent [3-glycidoxypropyl group, (meth) cryloyloxypropyl group, vinyl group, amino group, etc.]. ..

The silane compound (D) may preferably be a silane compound represented by the following formula (d1). When the pressure-sensitive adhesive composition contains a silane compound represented by the following formula (d1), the adhesiveness (or adhesiveness) can be further improved, so that a pressure-sensitive adhesive layer having good peeling resistance can be formed. In particular, even when the pressure-sensitive adhesive layer is applied (or laminated) to the transparent electrode in a high-temperature environment, the adhesiveness (or adhesiveness) can be maintained and high durability can be exhibited.

（式中、Ｂは、炭素数１〜２０のアルカンジイル基又は炭素数３〜２０の二価の脂環式炭化水素基を示し、前記アルカンジイル基及び前記脂環式炭化水素基を構成する−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置換されてもよく、Ｒ^７は炭素数１〜５のアルキル基を示し、Ｒ^８、Ｒ^９、Ｒ¹⁰、Ｒ¹¹及びＲ¹²はそれぞれ独立して、炭素数１〜５のアルキル基又は炭素数１〜５のアルコキシ基を示す）

(In the formula, B 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 7} represents an alkyl group having 1 to 5 carbon ^{atoms, R 8, R 9, R} 10, R 11 and R ¹² are each Independently, it indicates an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms).

In the formula (d1), B is an alkandiyl group having 1 to 20 carbon atoms such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, a heptamethylene group and an octamethylene group; a cyclobutylene group (for example, a cyclobutylene group). 1,2-Cyclobutylene group), cyclopentylene group (eg 1,2-cyclopentylene group), cyclohexylene group (eg 1,2-cyclohexylene group), cyclooctylene group (eg 1,2-cyclobutylene group) A divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms such as a cyclooctylene group), or an alcandiyl group thereof and −CH ₂₋ constituting the alicyclic hydrocarbon group is −O− or Indicates a group substituted with −CO−. Preferred B is an alkanediyl group having 1 to 10 carbon atoms. R ⁷ represents an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an s-butyl group, a t-butyl group, and a pentyl group, and R ⁸ , R ⁹ , R ^10, R ¹¹ and R ¹² are each independently the R ⁷ illustrative of the alkyl group having 1 to 5 carbon atoms, or a methoxy group, an ethoxy group, a propoxy group, i- propoxy, butoxy, s- butoxy group , T-Butoxy group and other alkoxy groups having 1 to 5 carbon atoms. Preferred R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are independently alkoxy groups having 1 to 5 carbon atoms. These silane compounds (D) can be used alone or in combination of two or more.

Specific examples of the silane compound represented by the above formula (d1) include (trimethoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, and the like. 1,3-bis (trimethoxysilyl) propane, 1,3-bis (triethoxysilyl) propane, 1,4-bis (trimethoxysilyl) butane, 1,4-bis (triethoxysilyl) butane, 1, 5-bis (trimethoxysilyl) pentane, 1,5-bis (triethoxysilyl) pentane, 1,6-bis (trimethoxysilyl) hexane, 1,6-bis (triethoxysilyl) hexane, 1,6- Bis (tripropoxysilyl) hexane, 1,8-bis (trimethoxysilyl) octane, 1,8-bis (triethoxysilyl) octane, 1,8-bis (tripropoxysilyl) octane and other bis (tri-C _{1) -5} alkoxysilyl) C _1-10 alkane; bis (dimethoxymethylsilyl) methane, 1,2-bis (dimethoxymethylsilyl) ethane, 1,2-bis (dimethoxyethylsilyl) ethane, 1,4-bis (dimethoxy) Methylsilyl) butane, 1,4-bis (dimethoxyethylsilyl) butane, 1,6-bis (dimethoxymethylsilyl) hexane, 1,6-bis (dimethoxyethylsilyl) hexane, 1,8-bis (dimethoxymethylsilyl) hexane _{) Octane, bis (diC 1-5} alkoxy C _1-5 alkylsilyl) C _1-10 alkanes such as 1,8-bis (dimethoxyethylsilyl) octane; 1,6-bis (methoxydimethylsilyl) hexane, 1 , 8-Bis (methoxydimethylsilyl) octane and other bis (mono C _1-5 alkoxy-di C _1-5 alkylsilyl) C _1-10 alkanes and the like. Of these, 1,2-bis (trimethoxysilyl) ethane, 1,3-bis (trimethoxysilyl) propane, 1,4-bis (trimethoxysilyl) butane, 1,5-bis (trimethoxysilyl) _{Bis (tri-C 1-3} alkoxysilyl) C _1-10 alkanes such as pentane, 1,6-bis (trimethoxysilyl) hexane and 1,8-bis (trimethoxysilyl) octane are preferred, especially 1,6. -Bis (trimethoxysilyl) hexane and 1,8-bis (trimethoxysilyl) octane are preferable.

The ratio of the silane compound (D) is, for example, 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, and more preferably 0.05 with respect to 100 parts by mass of the (meth) acrylic resin (B). ~ 3 parts by mass, more preferably 0.1 to 1 part by mass, particularly 0.2 to 0.5 parts by mass. When it is not more than the above upper limit value, it is advantageous to suppress bleed-out of the silane compound (D) from the pressure-sensitive adhesive layer, and when it is more than the above lower limit value, the pressure-sensitive adhesive layer is adhered to a metal layer, a glass substrate or the like. It becomes easy to improve the property (or adhesiveness), which is advantageous for improving the peeling resistance and the like.

[1-5] Antistatic agent (E)
The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include surfactants, siloxane compounds, conductive polymers, ionic compounds and the like. An ionic compound is preferable because it can improve the antistatic property of the pressure-sensitive adhesive (for example, suppress defects caused by static electricity when the release film, protective film, etc. are peeled off). Examples of the ionic compound include conventional ones. Examples of the cation component constituting the ionic compound include organic cations and inorganic cations. Examples of the organic cation include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, phosphonium cation and the like. 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 anion component constituting the ionic compound may be either an inorganic anion or an organic anion, but an anion component containing a fluorine atom is preferable from the viewpoint of 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-], and bis (fluorosulfonyl) imide anion [(FSO). ₂ ) ₂ N-], tetra (pentafluorophenyl) borate anion [(C ₆ F ₅ ) ₄ B-] and the like. These ionic compounds can be used alone or in combination of two or more. In particular, bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N-], bis (fluorosulfonyl) imide anion [(FSO ₂ ) ₂ N-], tetra (pentafluorophenyl) borate anion [(C) ₆ F ₅ ) ₄ B-] is preferable.
An ionic compound that is solid at room temperature is preferable in terms of stability over time in the antistatic performance of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

The ratio of the antistatic agent is, for example, 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, and more preferably 1 to 3 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin (B). Is.
It is generally known that the inclusion of an antistatic agent in a pressure-sensitive adhesive reduces the durability of the pressure-sensitive adhesive layer, but the pressure-sensitive adhesive composition of the present invention is in a high-temperature environment even if the pressure-sensitive adhesive is contained. Shows good durability underneath. Therefore, both good durability and antistatic performance can be achieved at the same time.

[1-6] Other Ingredients The pressure-sensitive adhesive composition contains a solvent, a cross-linking catalyst, an ultraviolet absorber, a weather-resistant stabilizer, a tack fire, a plasticizer, a softening agent, a dye, a pigment, an inorganic filler, light-scattering fine particles, and the like. The agent may be used alone or in combination of two or more. It is also useful to add an ultraviolet curable compound to the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer and then irradiate the pressure-sensitive adhesive composition with ultraviolet rays to cure the pressure-sensitive adhesive layer to obtain a harder pressure-sensitive adhesive layer. Examples of the cross-linking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin and melamine resin.

The pressure-sensitive adhesive composition may contain a rust preventive from the viewpoint of enhancing the metal corrosion resistance of the pressure-sensitive adhesive layer. Examples of the rust preventive agent include triazole compounds such as benzotriazole compounds; thiazole compounds such as benzothiazole compounds; imidazole compounds such as benzylimidazole compounds; imidazoline compounds; quinoline compounds; pyridine compounds; pyrimidines. Examples thereof include compounds; indol compounds; amine compounds; urea compounds; sodium benzoate; benzyl mercapto compounds; di-sec-butyl sulfide; and diphenyl sulfoxides.

In a preferred embodiment, the pressure-sensitive adhesive composition of the present invention is substantially free of a photopolymerization initiator and its degradation products. This is because the photopolymerization initiator and its decomposition products in the pressure-sensitive adhesive composition may inhibit the formation of the pressure-sensitive adhesive layer showing good durability. Here, substantially not contained means 1.0 part by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive composition, preferably 0.1 part by mass or less, and more preferably 0.01. It is most preferably parts by mass or less, more preferably 0.001 part by mass or less, and particularly preferably 0 parts by mass.

[2] Structure of Adhesive Layer and Optical Film with Adhesive Layer and Manufacturing Method The present invention includes an adhesive layer composed of the adhesive composition. The pressure-sensitive adhesive layer is formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to obtain a solvent-containing pressure-sensitive adhesive composition, and then applying and drying the pressure-sensitive adhesive composition on the surface of an optical film or a release film. Can be formed.

The present invention also includes an optical film with an adhesive layer, which includes an optical film and the adhesive layer laminated on at least one surface of the optical film.

Since the pressure-sensitive adhesive layer and the optical film with the pressure-sensitive adhesive layer of the present invention are formed from the pressure-sensitive adhesive composition, they have good durability even under severe durability conditions (for example, durability conditions of 100 ° C. or higher).

FIG. 1 is a schematic cross-sectional view showing an example of an optical film with an adhesive layer of the present invention. The optical film 1 with an adhesive layer shown in FIG. 1 is an optical film in which an optical film 10 and an adhesive layer 20 are laminated on one side of the optical film. The pressure-sensitive adhesive layer 20 is usually laminated directly on the surface of the optical film 10. The pressure-sensitive adhesive layer 20 may be laminated on both sides of the optical film 10.

When the pressure-sensitive adhesive layer 20 is laminated on the surface of the optical film 10, a primer layer is formed on the bonding surface of the optical film 10 and / or the bonding surface of the pressure-sensitive adhesive layer 20, or the surface activation treatment ( For example, plasma treatment, corona treatment, etc.) are preferably performed, and corona treatment is particularly preferable.

When the optical film 10 is a single-sided protective polarizing plate as shown in FIG. 2, the pressure-sensitive adhesive layer 20 is usually laminated on a polarizer surface, that is, a surface of the polarizing element 2 opposite to the first resin film 3. (Preferably directly laminated). When the optical film 10 is a double-sided protective polarizing plate as shown in FIG. 3, the pressure-sensitive adhesive layer 20 may be laminated on any of the outer surfaces of the first and second resin films 3 and 4, and both outer surfaces may be laminated. It may be laminated on.

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

The optical film 1 with an adhesive layer may include a separate film (release film) laminated on the outer surface of the adhesive layer 20. This separate film is usually peeled off and removed when the pressure-sensitive adhesive layer 20 is used (for example, when it is laminated on a transparent conductive electrode or a glass substrate). The separate film is a film in which, for example, the surface on which the pressure-sensitive adhesive layer 20 of a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarate is formed is subjected to a mold release treatment such as silicone treatment. good.

The optical film 1 with a pressure-sensitive adhesive layer dissolves or disperses each component constituting the pressure-sensitive adhesive composition in a solvent to obtain a solvent-containing pressure-sensitive adhesive composition, which is then applied and dried on the surface of the optical film 10. It can be obtained by forming the pressure-sensitive adhesive layer 20. Further, in the optical film 1 with an adhesive layer, an adhesive layer 20 is formed on the release-treated surface of the separate film in the same manner as described above, and the adhesive layer 20 is laminated (transferred) on the surface of the optical film 10. Can also be obtained.

The thickness of the pressure-sensitive adhesive layer is usually 2 to 40 μm, and is preferably 5 to 30 μm, more preferably 10 from the viewpoint of the durability of the optical film with the pressure-sensitive adhesive layer and the reworkability of the optical film with the pressure-sensitive adhesive layer. It is ~ 25 μm. When the thickness of the pressure-sensitive adhesive layer is not more than the above upper limit value, the reworkability is good, and when it is more than the above lower limit value, the durability is good.

The pressure-sensitive adhesive layer preferably exhibits a storage elastic modulus of 0.001 to 10 MPa in a temperature range of 23 to 120 ° C. This makes it possible to more effectively increase the durability of the optical film with the adhesive layer. "Exhibiting a storage elastic modulus of 0.001 to 10 MPa in a temperature range of 23 to 120 ° C." means that the storage elastic modulus is a value within the above range at any temperature in this range. Since the storage elastic modulus usually gradually decreases as the temperature rises, if both the storage elastic modulus at 23 ° C. and 120 ° C. are within the above range, the storage elastic modulus within the above range is shown at the temperature in this range. I can imagine. The storage elastic modulus of the pressure-sensitive adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device “DYNAMIC ANALYZER RDA II” manufactured by REOMETRIC.

The gel fraction can be used as an index of the crosslink density. Since the pressure-sensitive adhesive layer of the present invention has a predetermined crosslink density, it exhibits a predetermined gel fraction. That is, the gel fraction of the pressure-sensitive adhesive layer of the present invention may be, for example, 70 to 90% by mass, preferably 75 to 90% by mass, and more preferably 75 to 85% by mass. When the gel fraction is at least the lower limit value, it is advantageous in foaming resistance and reworkability of the pressure-sensitive adhesive layer, and when the gel fraction is at least the upper limit value, it is advantageous in peeling resistance. The gel fraction can be measured by the method described in the section of Examples.

[2-1] Optical film The optical film 10 constituting the optical film 1 with an adhesive layer may be various optical films (films having optical characteristics) that can be incorporated into an image display device such as a liquid crystal display device. The optical film 10 may have a single-layer structure (for example, an optical functional film such as a polarizer, a retardation film, a brightness improving film, an antiglare film, an antireflection film, a diffusion film, a condenser film, etc.). It may have a multi-layer structure (for example, a polarizing plate, a retardation plate, etc.). The optical film 10 is preferably a polarizing plate, a polarizing element, a retardation plate or a retardation film, and particularly preferably a polarizing plate or a polarizer. In the present specification, the optical film means a film that functions for displaying an image (display screen, etc.) (for example, a film that functions for improving the visibility of an image). Further, in the present specification, the polarizing plate means a resin film or a resin layer laminated on at least one surface of the polarizer, and the retardation plate means a resin film on at least one surface of the retardation film. Alternatively, it means a laminated resin layer.

[2-2] Polarizing Plates FIGS. 2 and 3 are schematic cross-sectional views showing an example of the layer structure of the polarizing plate. The polarizing plate 10a shown in FIG. 2 is a single-sided protective polarizing plate in which a first resin film 3 is laminated (or laminated and bonded) on one surface of a polarizing element 2, and the polarizing plate 10b shown in FIG. 3 is a polarizing plate 10b. This is a double-sided protective polarizing plate in which a second resin film 4 is further laminated (or laminated and bonded) on the other surface of the polarizer 2. The first and second resin films 3 and 4 can be attached to the polarizer 2 via an adhesive layer or an adhesive layer (not shown). The polarizing plates 10a and 10b may include films and layers other than the first and second resin films 3 and 4.

The polarizer 2 is a film having a property of absorbing linearly polarized light having a vibration plane parallel to its absorption axis and transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis (parallel to the transmission axis), for example. , A film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film can be used. Examples of the dichroic dye include iodine and a dichroic organic dye.

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

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

Usually, a film formed of a polyvinyl alcohol-based resin is used as the raw film for the polarizer 2. The polyvinyl alcohol-based resin can be formed into a film by a known method. The thickness of the raw film is usually 1 to 150 μm, and is preferably 10 μm or more in consideration of ease of stretching and the like.

The polarizer 2 is, for example, a step of uniaxially stretching the raw film, a step of dyeing the film with a dichroic dye and adsorbing the dichroic dye, a step of treating the film with a boric acid aqueous solution, and a step of treating the film with a boric acid aqueous solution. , The film is washed with water and finally dried to produce. The thickness of the polarizer 2 is usually 1 to 30 μm, and is preferably 20 μm or less, more preferably 15 μm or less, and particularly 10 μm or less, from the viewpoint of thinning the optical film 1 with the pressure-sensitive adhesive layer.

For the polarizer 2, which is formed by adsorbing and orienting a bicolor dye on a polyvinyl alcohol-based resin film, a single film of the polyvinyl alcohol-based resin film is used as the raw material film, and the film is subjected to uniaxial stretching treatment and bicolor dyeing. In addition to the method of performing dyeing treatment (referred to as method (1)), a coating liquid (aqueous solution, etc.) containing a polyvinyl alcohol-based resin is applied to the substrate film and dried to obtain a substrate having a polyvinyl alcohol-based resin layer. After obtaining a film, this is uniaxially stretched for each base film, the stretched polyvinyl alcohol-based resin layer is dyed with a bicolor dye, and then the base film is peeled off (method (method (method)). It can also be obtained by (2) and). As the base film, a film made of the same thermoplastic resin as the thermoplastic resin that can form the first and second resin films 3 and 4 described later can be used, and a polyester resin such as polyethylene terephthalate is preferable. , Polycarbonate resin, cellulose resin such as triacetyl cellulose, cyclic polyolefin resin such as norbornene resin, polystyrene resin and the like. By using the above method (2), it becomes easy to produce the polarizing element 2 of the thin film, and for example, even the production of the polarizer 2 having a thickness of 7 μm or less can be easily performed.

The first and second resin films 3 and 4 are independently translucent, preferably optically transparent thermoplastic resins such as chain polyolefin resins (eg polyethylene resins, polypropylene resins and the like). ), Polyethylene-based resins such as cyclic polyolefin-based resins (eg, norbornene-based resins, etc.); Cellulos-based resins (eg, cellulose ester-based resins, etc.); Polyester-based resins (eg, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc.); Polycarbonate Based resins (for example, polycarbonates derived from bisphenols such as 2,2-bis (4-hydroxyphenyl) propane); (meth) acrylic resins; polystyrene-based resins; polyether ether ketone-based resins; polysulfone-based resins, Alternatively, it may be a film made of a mixture thereof, a copolymer or the like. Of these, the first and second resin films 3 and 4 are films composed of a cyclic polyolefin resin, a polycarbonate resin, a cellulose resin, a polyester resin, a (meth) acrylic resin, and the like, respectively. Is preferable, and a film composed of a cellulose-based resin, a cyclic polyolefin-based resin, or the like is particularly preferable.

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

Cyclic polyolefin resin is a general term for resins containing norbornene, tetracyclododecene (also known as dimethanooctahydronaphthalene), or a cyclic olefin typified by a derivative thereof as a polymerization unit. Examples of the cyclic polyolefin resin include a ring-opened (co) polymer of a cyclic olefin and a hydrogenated product thereof, an addition polymer of a cyclic olefin, a cyclic olefin and a chain olefin such as ethylene and propylene, or an aromatic compound having a vinyl group. Examples thereof include the copolymers of the above, and modified (co) polymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof. Of these, a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as the cyclic olefin is preferable.

The cellulosic resin is preferably a cellulosic ester resin, that is, a partially or completely esterified product of cellulose, and examples thereof include an acetate ester of cellulose, a propionic acid ester, a butyric acid ester, and a mixed ester thereof. Of these, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like are preferable.

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

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

The (meth) acrylic resin that can form the first and second resin films 3 and 4 can be a polymer containing a constituent unit derived from a methacrylic acid ester as a main component (for example, containing 50% by mass or more thereof). , It is preferable that the copolymer is copolymerized with other copolymerization components. The (meth) acrylic resin may contain two or more kinds of structural units derived from methacrylic acid ester. _{Examples of the methacrylic acid ester include C 1 to} C ₄ alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate and butyl methacrylate.

Examples of the copolymerization component that can be copolymerized with the methacrylic acid ester include acrylic acid ester. _{The acrylic acid ester is preferably a C 1 to} C ₈ alkyl ester of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. Specific examples of other copolymerization components include unsaturated acids such as (meth) acrylic acid; aromatic vinyl compounds such as styrene, styrene halide, α-methylstyrene and vinyltoluene; and vinyl cyanide such as (meth) acrylonitrile. Compounds; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; unsaturated imides such as phenylmaleimide and cyclohexylmaleimide, other than acrylic acid esters having one polymerizable carbon-carbon double bond in the molecule. Compounds include. A compound having two or more polymerizable carbon-carbon double bonds in the molecule may be used as the copolymerization component. The copolymerization component can be used alone or in combination of two or more.

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

The (meth) acrylic resin may contain acrylic rubber particles from the viewpoint of film forming property on the film, impact resistance of the film, and the like. Acrylic rubber particles are particles containing an elastic polymer mainly composed of an acrylic acid ester as an essential component, and have a single-layer structure substantially consisting of only this elastic polymer, or one layer of an elastic polymer. There is a multi-layered structure. Examples of the elastic polymer include a crosslinked elastic copolymer containing an alkyl acrylate as a main component and copolymerizing another copolymerizable vinyl monomer and a crosslinkable monomer. _{Examples of the alkyl acrylate that is the main component of the elastic polymer include C 1 to} C ₈ alkyl esters of acrylic acids such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The alkyl group preferably has 4 or more carbon atoms.

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

The content of the acrylic rubber particles is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic resin. If the content of the acrylic rubber particles is too large, the surface hardness of the film may be lowered, and the solvent resistance to the organic solvent in the surface treatment agent may be lowered when the film is surface-treated. Therefore, the content of the acrylic rubber particles is usually 80 parts by mass or less, preferably 60 parts by mass or less, with respect to 100 parts by mass of the (meth) acrylic resin.

The first and second resin films 3 and 4 can contain conventional additives in the technical field of the present invention. Examples of the additive include an ultraviolet absorber, an infrared absorber, an organic dye, a pigment, an inorganic pigment, an antioxidant, an antistatic agent, a surfactant, a lubricant, a dispersant, a heat stabilizer and the like. Examples of the ultraviolet absorber include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, triazine compounds, cyano (meth) acrylate compounds, nickel complex salts and the like.

The first and second resin films 3 and 4 may be either a non-stretched film or a uniaxially or biaxially stretched film, respectively. The first resin film 3 and / or the second resin film 4 may be a protective film that plays a role of protecting the polarizer 2, or may be a protective film that also has an optical function such as a retardation film described later. good. The first resin film 3 and the second resin film 4 may be the same or different films.

Further, the first resin film 3 and / or the second resin film 4 has a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, and an antistatic layer on the outer surface (the surface opposite to the polarizer 2). , A surface treatment layer (coating layer) such as an antifouling layer and a conductive layer may be provided. The thicknesses of the first resin film 3 and the second resin film 4 are usually 1 to 150 μm, preferably 5 to 100 μm, more preferably 5 to 60 μm, still more preferably 50 μm or less (for example, 1 to 40 μm), in particular. It is 30 μm or less (for example, 5 to 25 μm).

In particular, in polarizing plates for small and medium-sized products such as smartphones and tablet terminals, thin ones having a thickness of 30 μm or less are often used as the first resin film 3 and / or the second resin film 4 due to the demand for thinning. Such a polarizing plate has a weak force for suppressing the contraction force of the polarizer 2, and tends to have insufficient durability. Even when such a polarizing plate is used as the optical film 10, the optical film 1 with an adhesive layer of the present invention has good durability.

The first and second resin films 3 and 4 can be attached to the polarizer 2 via an adhesive layer or an adhesive layer. As the adhesive 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, an adhesive composed of an aqueous polyvinyl alcohol-based resin solution, a water-based two-component urethane-based emulsion adhesive, an aldehyde compound, an epoxy compound, a melamine-based compound, a methylol compound, and an isocyanate compound. (Amine compounds, cross-linking agents such as polyvalent metal salts, etc.) can be mentioned. Of these, a water-based adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin can be preferably used. When a water-based adhesive is used, a step of bonding the polarizer 2 and the first and second resin films 3 and 4 and then drying the water-based adhesive to remove water contained in the water-based adhesive is carried out. It is preferable to do so. After the drying step, a curing step of curing at a temperature of, for example, about 20 to 45 ° C. may be provided.

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

When using an active energy ray-curable adhesive, the polarizer 2 and the first and second resin films 3 and 4 are bonded together, and if necessary, a drying step is performed, and then the active energy ray is irradiated. A curing step is performed to cure the active energy ray-curable adhesive. The light source of the active energy rays is not particularly limited, but ultraviolet rays having an emission distribution having a wavelength of 400 nm or less are preferable.

As a method of bonding the polarizer 2 and the first and second resin films 3 and 4, a surface activation treatment such as a saponification treatment, a corona treatment, or a plasma treatment is applied to at least one of these bonding surfaces. Examples include the method of application. When resin films are bonded to both sides of the polarizer 2, the adhesive for bonding these resin films may be the same type of adhesive or different types of adhesive.

The polarizing plates 10a and 10b may further include other films or layers. Specific examples thereof include, in addition to the retardation film described later, a brightness improving film, an antiglare film, an antireflection film, a diffusion film, a light-collecting film, an adhesive layer other than the adhesive layer 20, a coating layer, a protective film, and the like. .. The protective film is a film used for the purpose of protecting the surface of the optical film 10 such as a polarizing plate from scratches and stains. The optical film 1 with an adhesive layer is attached to, for example, a metal layer or a substrate and then peeled off. It is usually removed.

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

[2-3] Phase Difference Plate The retardation film included in the retardation plate is an optical film exhibiting optical anisotropy as described above, and can be used for the first and second resin films 3 and 4. In addition to the thermoplastic resins exemplified above, for example, polyvinyl alcohol-based resins, polyarylate-based resins, polyimide-based resins, polyether sulfone-based resins, polyvinylidene fluoride / polymethylmethacrylate-based resins, liquid crystal polyester-based resins, It can be a stretched film obtained by stretching a resin film made of an ethylene-vinyl acetate copolymer saponified product, a polyvinyl chloride-based resin, or the like about 1.01 to 6 times. Of these, a stretched film obtained by uniaxially stretching or biaxially stretching a polycarbonate resin film, a cyclic olefin resin film, a (meth) acrylic resin film, or a cellulose resin film is preferable. Further, in the present specification, the zero retardation film is also included in the retardation film. However, a zero retardation film can also be used as a protective film. In addition, films called uniaxial retardation films, wide viewing angle retardation films, low photoelastic modulus retardation films and the like can also be applied as retardation films.

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

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

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

Further, a film in which optical anisotropy is expressed by coating and orientation of a liquid crystal compound and a film in which optical anisotropy is developed by coating an inorganic layered compound can also be used as a retardation film. In such a retardation film, what is called a temperature-compensated retardation film, and a rod-shaped liquid crystal sold by JX Nikko Niseki Energy Co., Ltd. under the trade name of "NH film" are tilt-oriented. Film, a film with tilt-oriented disc-shaped liquid crystal sold under the trade name of "WV film" by Fuji Film Co., Ltd., and a complete biaxial film sold by Sumitomo Chemical Co., Ltd. under the trade name of "VAC film". There are oriented type films, biaxially oriented films also sold by Sumitomo Chemical Co., Ltd. under the trade name of "new VAC film". The resin film laminated on at least one surface of the retardation film may be, for example, the above-mentioned protective film.

[3] Optical Laminated Material The present invention includes an optical laminated body including the optical film with an adhesive layer and a base material laminated on the adhesive layer side of the optical film with an adhesive layer. Since the pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive composition, the optical laminate of the present invention has good durability even under severe durability conditions (for example, durability conditions of 100 ° C. or higher).

Examples of the base material include conventional base materials such as a glass substrate, a transparent electrode, a plastic film, an organic conductive film, a metal layer, and an overcoat resin layer.

4 to 8 are schematic cross-sectional views showing an example of an optical laminate according to the present invention.

In the optical laminate 5 shown in FIG. 4, the electrode layer 30 laminated on the substrate 40 is laminated on the surface of the optical film 1a with an adhesive layer (or the polarizing plate 1a with an adhesive layer) on the adhesive layer side. It is an optical laminate. The optical film 1a with an pressure-sensitive adhesive layer is obtained by laminating the pressure-sensitive adhesive layer 20 on the surface of the polarizing plate 10a on the side of the polarizer 2.

In the optical laminate 6 shown in FIG. 5, the electrode layer 30 laminated on the substrate 40 is laminated on the surface of the optical film 1b with an adhesive layer (or the polarizing plate 1b with an adhesive layer) on the adhesive layer side. It is an optical laminate. The optical film 1b with an adhesive layer is an optical film in which the adhesive layer 20 is laminated on the surface of the polarizing plate 10b on the second resin film 4 side.

The optical laminates 5 and 6 can be obtained by laminating an optical film (1a, 1b) with an adhesive layer on the electrode layer 30 laminated on the substrate 40 via the adhesive layer 20.

Examples of the method for forming the electrode layer 30 on the substrate 40 include a sputtering method, a vacuum vapor deposition method, a sputtering method, an ion plating method, an inkjet printing method, and a gravure printing method. The substrate 40 may be a transparent substrate constituting a liquid crystal cell included in the touch input element, and is preferably a glass substrate. As the material of the glass substrate, soda lime glass, low-alkali glass, non-alkali glass and the like can be used. The electrode layer 30 may be formed on the entire surface of the substrate 40, or may be formed on a part thereof.

The electrode layer 30 contains, for example, at least one metal element selected from an alloy containing aluminum, copper, silver, iron, tin, zinc, nickel, molybdenum, chromium, tungsten, lead and two or more of these metals. It may be a metal layer containing. Of these, from the viewpoint of conductivity, a metal layer containing at least one metal element selected from aluminum, copper, silver and gold is preferable. From the viewpoint of conductivity and cost, a metal layer containing an aluminum element is more preferable, and a metal layer containing an aluminum element as a main component (50% by mass or more of all metal components constituting the metal layer) is more preferable.
The metal layer may be a layer in which a metal mesh in which a thin metal wiring layer is arranged on a substrate, metal nanoparticles, or metal nanowires are added to a binder.

Examples of the electrode layer 30 include those composed of tin oxide, indium oxide, zinc oxide, gallium oxide, aluminum oxide, and a mixture thereof. ITO is preferable in terms of conductivity and visible light transmittance.

The electrode layer 30 is preferably a transparent electrode and a metal layer formed by a sputtering method, an inkjet printing method or a gravure printing method, and more preferably a transparent electrode and a metal layer formed by a sputtering method.
The thickness of the electrode layer 30 is not particularly limited, but is usually 3 μm or less, preferably 1 μm or less, more preferably 0.8 μm or less, and usually 0.01 μm or more. Further, when the electrode layer 30 is a metal wiring layer (for example, a metal mesh), the line width of the metal wiring is usually 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and usually 0.5 μm or more. Is.

The optical laminate 7 shown in FIG. 6 is an optical laminate in which the pressure-sensitive adhesive layer 20 of the optical film 1 with the pressure-sensitive adhesive layer is laminated on the substrate 40.

In the optical laminate 8 shown in FIG. 7, a resin layer 50 further laminated on the surface of the electrode layer 30 laminated on the substrate 40 (on the surface opposite to the substrate 40) is attached with the adhesive layer. It is an optical laminate laminated on the surface of the optical film 1 on the pressure-sensitive adhesive layer 20 side. Examples of the resin forming the resin layer 50 include resins constituting the first or second resin film of the above-exemplified example.

In the optical laminate 9 shown in FIG. 8, a plurality of electrode layers 30 are laminated on the substrate 40 at predetermined intervals in the vertical and horizontal directions, and the electrode layers 30 are located between (or gaps) between the plurality of electrode layers 30 and the electrode layers 30. It is the same as the optical laminate 7 except that the resin layer 50 is formed (or laminated) on the surface (on the surface opposite to the substrate 40). In the form of the optical laminate 9 (the electrode layer 30 is patterned in a predetermined shape), the electrode layer 30 may be, for example, a metal wiring layer of a touch input element included in a touch input type liquid crystal display device. good.

In the optical laminate 9, the plurality of electrode layers 30 may or may not be in contact with the pressure-sensitive adhesive layer 20 in whole or in part. Further, the electrode layer 30 may be a continuous film containing a transparent electrode, a metal or an alloy. The resin layer 50 may be omitted.

[4] Liquid Crystal Display Device The pressure-sensitive adhesive layer, the optical film with the pressure-sensitive adhesive layer, and the optical laminate of the present invention can be used in a liquid crystal display device, and the liquid crystal display device has good durability.

The liquid crystal display device may be a touch input type liquid crystal display device having a touch panel function. The touch input type liquid crystal display device includes a touch input element including a liquid crystal cell and a backlight. The configuration of the touch panel may be a known method (for example, out-cell type, on-cell type, in-cell type, etc.), and the operation method of the touch panel is a known method, for example, a resistive film method or a capacitance method (surface type static). It may be an electrostatic capacity method, a projection type capacitance method) or the like. The optical film with an adhesive layer according to the present invention may be arranged on the visual side of the touch input element (liquid crystal cell), on the backlight side, or on both sides. The drive method of the liquid crystal cell may be any conventionally known method such as a TN method, a VA method, an IPS method, a multi-domain method, and an OCB method. In the liquid crystal display device, the substrate 40 included in the optical laminate may be a substrate (typically a glass substrate) included in the liquid crystal cell.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples. Hereinafter, the amounts used, the parts representing the contents and% are based on mass unless otherwise specified.

<Manufacturing Example 1: Production of (meth) acrylic resin (B-1) for adhesive layer>
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, a monomer having the composition shown in Table 1 (the numerical value in Table 1 is a mass part) is mixed with 81.8 parts of ethyl acetate. The obtained solution was charged. After replacing the air in the reaction vessel with nitrogen gas, the internal temperature was adjusted to 60 ° C. Then, a solution prepared by dissolving 0.12 parts of azobisisobutyronitrile in 10 parts of ethyl acetate was added. After keeping the temperature at the same temperature for 1 hour, while keeping the internal temperature at 54 to 56 ° C., ethyl acetate was continuously 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. After maintaining the internal temperature at 54 to 56 ° C. until 12 hours have passed from the start of addition of ethyl acetate, ethyl acetate was further added to adjust the polymer concentration to 20%, and the (meth) acrylic resin (meth) acrylic resin (meth) An ethyl acetate solution of B-1) was obtained. The weight average molecular weight Mw of the obtained (meth) acrylic resin (B-1) was 1.38 million, and the ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn was 4.8.

<Manufacturing Examples 2 and 3: Production of (meth) acrylic resins (B-2) and (B-3) for the pressure-sensitive adhesive layer>
Ethyl acetate solutions of (meth) acrylic resins (B-2) and (B-3) were obtained in the same manner as in Production Example 1 except that the composition of the monomers was the composition shown in Table 1. (Resin concentration: 20%). The weight average molecular weight Mw of the obtained (meth) acrylic resin (B-2) is 1.42 million, Mw / Mn is 5.2, and the weight average molecular weight Mw of the (meth) acrylic resin (B-3) is It was 1.36 million and Mw / Mn was 4.1.

In the above production example, the weight average molecular weight Mw and the number average molecular weight Mn are four "TSKgel XL" manufactured by Toso Co., Ltd. and "Shodex GPC KF-" manufactured by Showa Denko KK as columns in the GPC apparatus. 802 ”is arranged by connecting a total of 5 pieces in series, using tetrahydrofuran as the eluent, sample concentration 5 mg / mL, sample introduction amount 100 μL, temperature 40 ° C., flow velocity 1 mL / min, standard polystyrene conversion. Measured by The conditions for obtaining the GPC emission curve were the same.

The glass transition temperature Tg was measured using a differential scanning calorimeter (DSC) "EXSTAR DSC6000" manufactured by SII Nanotechnology Co., Ltd. in a nitrogen atmosphere, a measurement temperature range of -80 to 50 ° C, and a temperature rise rate of 10 ° C / min. It was measured under the conditions of.

The composition of the monomers in each production example (the numerical values in Table 1 are parts by mass) is shown in Table 1.

The abbreviations in the "Monomer Composition" column of Table 1 mean the following monomers.
BA: Normal Butyl Acrylate (Homopolymer Glass Transition Temperature: -54 ° C),
MA: Methyl acrylate (glass transition temperature of homopolymer: 10 ° C),
HEA: 2-Hydroxyethyl acrylate.
5HPA: 5-Hydroxypentyl acrylate AAEM: Acetacetoxyethyl methacrylate BMAA: Butoxymethylacrylamide PEA2: Phenoxydiethylene glycol acrylate AA: Acrylic acid

<Examples 1 to 6 and Comparative Examples 1 to 6>
(1) Preparation of Adhesive Composition Table 2 shows in an ethyl acetate solution (resin concentration: 20%) of the (meth) acrylic resin obtained in the above production example with respect to 100 parts of the solid content of the solution. Silane compound (A) containing an amount (part by mass) of Si—Si bond, cross-linking agent (C), silane compound (D) not containing Si—Si bond, Examples 1, 3 and 5, Comparative Example 1, In Nos. 3 and 5, the antistatic agent (E) was further mixed, and then ethyl acetate was added so that the solid content concentration became 14% to obtain a pressure-sensitive adhesive composition. When the product used contains a solvent or the like, the blending amount of each blending component shown in Table 2 is the number of parts by mass as the solid content contained therein.

Details of each compounding ingredient shown by abbreviation in Table 2 are as follows.

(Silane compound (A) containing a Si—Si bond)
A-1: Product name "Ogsol SI-20-10" obtained from Osaka Gas Chemical Co., Ltd. Weight average molecular weight (Mw) is 1600 and number average molecular weight (Mn) is 1000 in terms of standard polystyrene by GPC. A methylphenylpolysilane compound having a hydroxyl group.
(Crosslinking agent (C))
C-1: Ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75%), trade name "Coronate L" obtained from Tosoh Corporation.

(Silane compound (D) containing no Si—Si bond)
D-1: 1,6-bis (trimethoxysilyl) hexane.

(Antistatic agent (E))
E-1: N-decylpyridinium bis (fluorosulfonyl) imide.

(2) Preparation of Adhesive Layer Separate film made of polyethylene terephthalate film that has undergone mold release treatment for each adhesive composition prepared in (1) above [trade name "PLR-382190 obtained from Lintec Co., Ltd." ]] Was applied to the release-treated surface using an applicator so that the thickness after drying was 20 μm, and dried at 100 ° C. for 1 minute to prepare an adhesive layer (adhesive sheet).

(3) Preparation of Optical Film with Adhesive Layer (P-1) Polyvinyl alcohol film with an average degree of polymerization of about 2400, a saponification degree of 99.9 mol%, and a thickness of 60 μm. -PE # 6000 "] is immersed in pure water at 37 ° C., and then an aqueous solution containing iodine and potassium iodide (iodine / potassium iodide / water (mass ratio) = 0.04 / 1.5 / 100). Was immersed in 30 ° C. Then, it was immersed in an aqueous solution containing potassium iodide and boric acid (potassium iodide / boric acid / water (mass ratio) = 12 / 3.6 / 100) at 56.5 ° C. The film was washed with pure water at 10 ° C. and then dried at 85 ° C. to obtain a polarizer having a thickness of about 23 μm in which iodine was adsorbed and oriented on polyvinyl alcohol. The stretching was mainly carried out in the steps of iodine staining and boric acid treatment, and the total stretching ratio was 5.3 times.

A transparent protective film made of a triacetyl cellulose film having a thickness of 40 μm [trade name “KC40A” manufactured by Konica Minolta Opto Co., Ltd.] is applied to one side of the obtained polarizing element via an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin. And pasted together. Next, a zero retardation film made of a cyclic polyolefin resin having a thickness of 23 μm [trade name “ZEONOR” manufactured by Nippon Zeon Corporation] is applied to the surface of the above-mentioned polarizer on the opposite side to the triacetyl cellulose film, and a polyvinyl alcohol-based film is applied. A laminated polarizing plate was produced via an adhesive composed of an aqueous solution of a resin. Next, the surface of the zero retardation film opposite to the surface in contact with the polarizer is subjected to a corona discharge treatment for improving adhesion, and then the surface is opposite to the separate film of the pressure-sensitive adhesive layer produced in (2) above. After laminating the side surface (adhesive layer surface) with a laminator, the film was cured under the conditions of a temperature of 23 ° C. and a relative humidity of 65% for 7 days to obtain an optical film (P-1) with an adhesive layer.

(4) Evaluation of Durability of Optical Film with Adhesive Layer The optical film with adhesive layer (P-1) produced in (3) above is 300 mm × 220 mm so that the stretching axis direction of the polarizing plate is the long side. The separate film was peeled off by cutting into a size, and the exposed pressure-sensitive adhesive layer surface was bonded to a glass substrate or a glass substrate with ITO (tin-doped indium oxide). The obtained test piece to which the glass substrate was attached (optical film with an adhesive layer to which the glass substrate was attached) 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. For the glass substrate, Corning's non-alkali glass product name "Eagle XG" was used. Further, as the glass substrate with ITO, a non-alkali glass [trade name "Eagle XG"] manufactured by Corning Inc. on which an ITO layer of 30 nm was formed by ITO vapor deposition was used.
The following durability test was carried out on the obtained optical laminate.

[Durability test]
-Heat resistance test (glass substrate) that is held for 500 hours under dry conditions at a temperature of 105 ° C.
-Heat resistance test (glass with ITO) that is held for 500 hours under dry conditions at a temperature of 105 ° C.

The optical laminate after each test was visually observed, and the presence or absence of appearance changes such as floating, peeling, and foaming of the adhesive layer was visually observed, and the durability was evaluated according to the following evaluation criteria. The results are shown in Table 3.

5: No change in appearance such as floating, peeling, foaming, etc.
4: There is almost no change in appearance such as floating, peeling, and foaming.
3: Appearance changes such as floating, peeling, and foaming are slightly noticeable.
2: Appearance changes such as floating, peeling, and foaming are noticeable.
1: Appearance changes such as floating, peeling, and foaming are noticeably observed.

(6) Evaluation of antistatic property of optical film with adhesive layer After peeling off the separator of the obtained polarizing film with adhesive layer, the surface resistance value of the adhesive is measured by the surface specific resistance measuring device [Mitsubishi Chemical Co., Ltd.] "High Restor-up MCP-HT450" (trade name)]. The measurement was carried out under the measurement conditions of an applied voltage of 250 V and an applied time of 10 seconds. When the surface resistance value is 1.0 × 10 ¹² Ω / □ or less, good antistatic property can be obtained.

[Gel fraction of adhesive sheet]
The gel fraction evaluation method of the pressure-sensitive adhesive sheet of this invention is shown. The larger the gel fraction, the more cross-linking reactions are proceeding in the pressure-sensitive adhesive, which can be used as a guide for the cross-linking density. The gel fraction is a value measured according to the following (a) to (d).

(A) An adhesive sheet having an area of about 8 cm × about 8 cm and a metal mesh (whose weight is Wm) made of SUS304 having an area of about 10 cm × about 10 cm are bonded together.
(B) The bonded product obtained in (I) above is weighed to a mass of Ws, then folded four times so as to wrap the adhesive sheet, stapled, and then weighed. Let the mass be Wb.
(C) The mesh stapled in (II) above is placed in a glass container, 60 mL of ethyl acetate is added and immersed, and then the glass container is stored at room temperature for 3 days.
(D) The mesh is taken out from the glass container, dried at 120 ° C. for 24 hours, weighed, the mass is Wa, and the gel fraction is calculated based on the following formula.
Gel fraction (mass%) = [{Wa- (Wb-Ws) -Wm} / (Ws-Wm)] x 100

1,1a, 1b ... Optical film with adhesive layer, 2 ... Polarizer, 3 ... First resin film, 4 ... Second resin film, 5,6,7,8,9 ... Optical laminate, 10 ... Optical film 10, a, 10b ... Polarizing plate, 20 ... Adhesive layer, 30 ... Electrode layer, 40 ... Substrate, 50 ... Resin layer.

Claims (20)

(Meth) viewed contains an acrylic resin (B) and Si-Si bonds and containing silane compound (A), the weight average molecular weight of (meth) acrylic resin (B) is an on polystyrene 1 million ,
The silane compound (A) contains the structural unit (a2) and / or the structural unit (a3):

(In the formula, R ^{4 to} R ⁶ each independently represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group or a hydroxy group).
A pressure-sensitive adhesive composition , which is a polysilane compound containing. The pressure-sensitive adhesive composition according to claim 1, wherein the silane compound (A) is a silane compound having a weight average molecular weight of 300 or more. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the silane compound (A) is a polysilane compound having a crosslinked structure in the molecule. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the silane compound (A) is a compound having a hydroxy group. Further, the cross-linking agent (C), and Si-Si bonds was not silane compound containing containing (D), pressure-sensitive adhesive composition according to claim 1. The (meth) acrylic resin (B) has the following formula (b1).

(In the formula, n represents an integer of 1 to 4, A ¹ represents a hydrogen atom or an alkyl group, X ¹ represents a methylene group which may have a substituent, and when n is 2 or more, the above. Substituents may be the same or different)
A structural unit derived from the hydroxy group-containing (meth) acrylate (b1) represented by the following formula (b2).

(In the formula, m represents an integer of 5 or more, A ² represents a hydrogen atom or an alkyl group, X ² represents a methylene group which may have a substituent, and the substituents are the same or different. May be good)
Claims 1 to 5 include at least one selected from the structural unit derived from the hydroxy group-containing (meth) acrylate (b2) represented by and the structural unit derived from the acetacetyl group-containing (meth) acrylate (b3). The pressure-sensitive adhesive composition according to any one of. The (meth) acrylic resin (B) contains a hydroxy group-containing (meth) acrylate (b1) -derived structural unit and a hydroxy group-containing (meth) acrylate (b2) -derived structural unit or an acetoacetyl group-containing (meth) acrylate. The pressure-sensitive adhesive composition according to claim 6 , which comprises a structural unit derived from (b3). Mass ratio of the structural unit derived from the hydroxy group-containing (meth) acrylate (b1) to the structural unit derived from the hydroxy group-containing (meth) acrylate (b2) or the structural unit derived from the acetacetyl group-containing (meth) acrylate (b3). The pressure-sensitive adhesive composition according to claim 7 , wherein (b1) / (b2 or b3) is 14 to 1. The (meth) acrylic resin (B) is derived from a structural unit derived from an alkyl acrylate (b4) having a homopolymer glass transition temperature of less than 0 ° C. and an alkyl acrylate (b5) having a homopolymer glass transition temperature of 0 ° C. or higher. The pressure-sensitive adhesive composition according to any one of claims 1 to 8 , which comprises the constituent unit of the above. Mass ratio (b4) / of the structural unit derived from the alkyl acrylate (b4) whose homopolymer glass transition temperature is less than 0 ° C. and the structural unit derived from the alkyl acrylate (b5) whose homopolymer glass transition temperature is 0 ° C. or higher. The pressure-sensitive adhesive composition according to claim 9 , wherein (b5) is 0.1 to 10. The ratio of the carboxyl group-containing (meth) acrylate-derived constituent units contained in the (meth) acrylic resin (B) to 100 parts by mass of all the constituent units constituting the (meth) acrylic resin (B) is 1. The pressure-sensitive adhesive composition according to any one of claims 1 to 10 , which is 0 parts by mass or less. The pressure-sensitive adhesive composition according to any one of claims 5 to 11 , wherein the cross-linking agent (C) is an isocyanate compound. The pressure-sensitive adhesive composition according to any one of claims 5 to 12 , wherein the ratio of the cross-linking agent (C) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin (B). .. The silane compound (D) has the following formula (d1).

(In the formula, B 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 7} represents an alkyl group having 1 to 5 carbon ^{atoms, R 8, R 9, R} 10, R 11 and ^{R 12} are each Independently, it indicates an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms).
The pressure-sensitive adhesive composition according to any one of claims 5 to 13 , which is a silane compound represented by. The pressure-sensitive adhesive composition according to any one of claims 5 to 14 , wherein the ratio of the silane compound (D) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin (B). .. The pressure-sensitive adhesive composition according to any one of claims 1 to 15 , which does not substantially contain a photopolymerization initiator and a decomposition product thereof. A pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 16. A pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition containing a silane compound (A) containing a Si—Si bond.
The silane compound (A) contains the structural unit (a2) and / or the structural unit (a3):

(In the formula, R ^{4 to} R ⁶ each independently represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group or a hydroxy group).
Is a polysilane compound containing
The gel fraction of the pressure-sensitive adhesive layer is 70% to 90%, viscosity Chakuzaiso. An optical film with an adhesive layer including an optical film and an adhesive layer laminated on at least one surface of the optical film, wherein the adhesive layer is a silane compound (A) containing a Si—Si bond. adhesive layer der including the pressure-sensitive adhesive composition containing a is,
The silane compound (A) contains the structural unit (a2) and / or the structural unit (a3):

(In the formula, R ^{4 to} R ⁶ each independently represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group or a hydroxy group).
An optical film with an adhesive layer, which is a polysilane compound containing. An optical laminate comprising the optical film with an adhesive layer according to claim 19 and a base material laminated on the adhesive layer side of the optical film with an adhesive layer.

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