TW201835272A - Adhesive composition - Google Patents

Abstract

The purpose of present invention is to provide an adhesive composition capable of forming an adhesive layer exhibiting good durability even under severe durability conditions. Provided is an adhesive composition having a silane compound (A) containing a Si - Si bond.

Description

 Adhesive composition  

The present invention relates to a useful adhesive composition for an optical member, an adhesive layer made of the adhesive composition, and an adhesive layer containing the adhesive layer, which is used in a liquid crystal display device or the like. An optical film and an optical layered body containing the optical film to which the adhesive layer is applied.

An optical film which is a polarizing plate formed by laminating a transparent resin film on one surface or both surfaces of a polarizing plate is widely used as an optical member constituting an image display device such as a liquid crystal display device. Many of the optical films of the polarizing plate are used in combination with other members (for example, liquid crystal cells in a liquid crystal display device) via an adhesive layer (refer to Patent Document 1). For this reason, as an optical film, an optical film to which an adhesive layer is provided with an adhesive layer on one surface thereof is known.

 [Previous Technical Literature]    [Patent Literature]  

Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-229321

In recent years, liquid crystal display devices have been developed in mobile device applications represented by smart phones or tablet type terminals or in automotive device applications represented by car navigation systems. In such an application, the durability of the device is an important issue because it may be in an environment that is more severe than the use of television in the home.

In an optical film to which an adhesive layer is formed, such as a liquid crystal display device, durability is also required. That is, the adhesive layer assembled in a liquid crystal display device or the like is placed in an environment of high temperature or high temperature and high humidity, or is placed in an environment of alternating high temperature and low temperature, but an adhesive layer is provided. Even in such an environment, the optical film is required to have an unsuitable phenomenon of suppressing generation of floating or peeling, foaming of the adhesive layer, etc., at the interface between the adhesive layer and the optical member to be bonded thereto. It is also required not to deteriorate the optical characteristics. In particular, in the case where the optical film is a polarizing plate, it is required to have higher durability in the adhesive layer than in a general optical film due to strong shrinkage stress in a high temperature environment. Since the demand for improved durability of the liquid crystal display device described above is highly demanded, the durability required for the adhesive layer has recently become very severe.

Accordingly, it is an object of the present invention to provide an adhesive composition capable of forming an adhesive layer exhibiting good durability, an adhesive layer formed of the adhesive composition, and containing even under such severe durability conditions. An optical film to which an adhesive layer is applied to the adhesive layer, and an optical layered body containing the optical film to which the adhesive layer is applied.

The inventors of the present invention have completed the present invention in order to solve the above problems and have been closely examined.

That is, the present invention encompasses the following invention.

[1] An adhesive composition containing a Si-Si-bonded decane compound (A).

[2] The adhesive composition according to [1], wherein the decane compound (A) is a decane compound having a weight average molecular weight of 300 or more.

[3] The adhesive composition according to [1] or [2], wherein the decane compound (A) is a polydecane compound having a crosslinked structure in a molecule.

[4] The adhesive composition according to any one of [1] to [3] wherein the decane compound (A) is a compound having a hydroxyl group.

[5] The adhesive composition according to any one of [1] to [4] which comprises a (meth)acrylic resin (B), a crosslinking agent (C), and no Si-Si Combined decane compound (D).

[6] The adhesive composition according to any one of [1] to [5] wherein the weight average molecular weight of the (meth)acrylic resin (B) is 1,000,000 or more in terms of polystyrene.

The adhesive composition according to any one of the above aspects, wherein the (meth)acrylic resin (B) contains at least one selected from the group consisting of the following formula (b1) From a structural unit containing a hydroxy (meth) acrylate (b1)

(wherein, 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 aforementioned substituent may be the same or Can be different)

It is derived from a structural unit containing a hydroxy (meth) acrylate (b2) as shown by the following formula (b2)

(wherein m represents an integer of 5 or more, A ² represents a hydrogen atom or an alkyl group, and X ² represents a methylene group which may have a substituent, and the above substituents may be the same or may be different)

And a structural unit derived from an ethyl acetyl (meth) acrylate (b3).

[8] The adhesive composition according to [7], wherein the (meth)acrylic resin (B) contains a structural unit derived from a hydroxyl group (meth) acrylate (b1), and is derived from The structural unit of the hydroxy(meth)acrylate (b2) is derived from a structural unit containing an ethyl acetoxy (meth) acrylate (b3).

[9] The adhesive composition according to [8], which is derived from a structural unit containing a hydroxy (meth) acrylate (b1) and a structure derived from a hydroxy (meth) acrylate (b2)-containing structure The mass ratio (b1) / (b2 or b3) of the unit derived from the structural unit containing ethyl acetoxy (meth) acrylate (b3) is 14 to 1.

[10] The adhesive composition according to any one of [5], wherein the (meth)acrylic resin (B) contains a glass transition temperature derived from a homopolymer of less than 0. The structural unit of the alkyl acrylate (b4) at °C, and the structural unit derived from the alkyl acrylate (b5) having a glass transition temperature of 0 ° C or higher derived from the homopolymer.

[11] The adhesive composition according to [10], wherein the glass transition temperature derived from the homopolymer is a structural unit of the alkyl acrylate (b4) which is less than 0 ° C, and is derived from a homopolymer. The mass ratio (b4)/(b5) of the structural unit of the alkyl acrylate (b5) having a glass transition temperature of 0 ° C or more is 0.1 to 10.

The adhesive composition according to any one of the above aspects, wherein the (meth)acrylic resin (B) is derived from a carboxyl group-containing (meth) acrylate. The ratio of the structural unit is 1.0 part by mass or less based on 100 parts by mass of the total structural unit constituting the (meth)acrylic resin (B).

[13] The adhesive composition according to any one of [12], wherein the crosslinking agent (C) is an isocyanate compound.

The adhesive composition according to any one of the above aspects, wherein the ratio of the crosslinking agent (C) is 100 parts by mass relative to the (meth)acrylic resin (B). 0.01 to 10 parts by mass.

[15] The adhesive composition according to any one of [5], wherein the decane compound (D) is a decane compound represented by the following formula (d1)

(wherein B represents an alkanediyl group having 1 to 20 carbon atoms (i.e., alkylene group) or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and constitutes the aforementioned alkanediyl group and the aforementioned alicyclic ring. The -CH ₂ - of the formula hydrocarbyl group may also be substituted with -O- or -CO-, R ⁷ represents an alkyl group having 1 to 5 carbon atoms, and R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² It is independently an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.

[10] The adhesive composition according to any one of [5], wherein the ratio of the decane compound (D) is 0.01% by mass based on 100 parts by mass of the (meth)acrylic resin (B). Up to 10 parts by mass.

[17] The adhesive composition according to any one of [1] to [16] which is substantially free of a photopolymerization initiator and a decomposition product of a photopolymerization initiator.

[18] An adhesive layer comprising the adhesive composition according to any one of [1] to [17].

[19] The adhesive layer according to [18], wherein the adhesive layer has a gel fraction of 70 to 90%.

[20] An optical film to which an adhesive layer is applied, comprising an optical film and an adhesive layer laminated on at least one side of the optical film, the adhesive layer being as described in [18] or [19] Adhesive layer.

[21] An optical laminate comprising the optical film to which the adhesive layer is described in [20] and a substrate laminated on the side of the adhesive layer of the optical film to which the adhesive layer is applied.

The adhesive composition of the present invention can form an adhesive layer having good durability even under severe durability conditions.

1, 1a, 1b‧‧‧ optical film with adhesive layer

2‧‧‧ polarizer

3‧‧‧1st resin film

4‧‧‧2nd resin film

5, 6, 7, 8, 9‧‧‧ Optical laminates

10‧‧‧Optical film

10a, 10b‧‧‧ polarizing plate

20‧‧‧Adhesive layer

30‧‧‧electrode layer

40‧‧‧Substrate

50‧‧‧ resin layer

Fig. 1 is a schematic cross-sectional view showing an example of an optical film to which an adhesive layer is formed by the adhesive composition of the present invention.

Fig. 2 is a schematic cross-sectional view showing an example of a layer configuration of a polarizing plate.

Fig. 3 is a schematic cross-sectional view showing another example of the layer configuration of the polarizing plate.

Fig. 4 is a schematic cross-sectional view showing an example of an optical layered body containing an adhesive layer optical film formed of the adhesive composition of the present invention.

Fig. 5 is a schematic cross-sectional view showing another example of an optical layered body comprising an adhesive layer optical film formed of the adhesive composition of the present invention.

Fig. 6 is a schematic cross-sectional view showing another example of an optical layered body comprising an adhesive layer optical film formed of the adhesive composition according to the present invention.

Fig. 7 is a schematic cross-sectional view showing still another example of an optical layered body comprising an adhesive layer optical film formed of the adhesive composition according to the present invention.

Fig. 8 is a schematic cross-sectional view showing still another example of an optical layered body comprising an adhesive layer optical film formed of the adhesive composition of the present invention.

 [Best Mode for Carrying Out the Invention]  

[1] Adhesive composition

The adhesive composition of the present invention contains a decane compound (A) having Si-Si bonding.

[1-1] Si-Si-bonded decane compound (A)

The decane compound (A) means a decane compound containing a Si (germanium atom)-Si (germanium atom) bond. The decane compound (A) is preferably a polydecane compound containing two or more Si-Si bonds from the viewpoint of durability of the adhesive layer. The Si-Si bond may be in the main chain or in the side chain, usually with Si-Si bonding in the main chain. The structural form of the decane compound (A) is not particularly limited, and may be, for example, a linear chain, a branched chain, a cyclic, or a crosslinked structure. Among them, a polydecane compound having a crosslinked chain shape, particularly a crosslinked structure in a molecule is preferable, and when the polydecane compound is contained in the adhesive composition, the durability of the adhesive layer can be efficiently improved. More preferably, it is a mesh-like (or network-like) polydecane compound, and when the polydecane compound is contained in the adhesive composition, the durability of the adhesive layer can be further improved. Here, the mesh shape (or the network shape) means that a plurality of erbium atoms are connected to each other and connected to a three-dimensional mesh structure. Further, although the number of meshes in the mesh-like structure is not particularly limited, generally, two or more mesh structures are referred to as mesh shapes (or mesh shapes).

Further, in the case where a substituent is bonded to a ruthenium atom contained in the decane compound (A), a ruthenium atom and a part of the substituent may form a mesh structure.

The decane compound (A) of the ideal aspect has at least one polydecane compound which is a structural unit represented by the following formulas (a1) to (a4).

(wherein R ¹ to R ⁶ are each independently represented by a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyl group, an amine group, or a substituted amine group)

Among R ¹ to R ⁶ in the above formulae (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, and a secondary-butyl group. a linear or branched chain C _1-10 alkyl group such as a tertiary-butyl group, preferably a linear or branched chain C _1-6 alkyl group, more preferably a linear chain or Tiller chain C _1-4 alkyl. Examples of the cycloalkyl group include a C _5-8 cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. Examples of the aryl group include a C _6-12 aryl group such as a phenyl group, an alkylphenyl group (methylbenzene (toluene) group or a dimethylbenzene (xylene) group), a biphenyl group or a naphthyl group. Ideally, C _6-10 aryl. Examples of the aralkyl group include a C _7-14 aralkyl group such as a benzyl group or a phenethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a secondary-butoxy group, a tertiary-butoxy group, and the like. a linear or branched chain C _1-10 alkoxy group, preferably a linear or branched chain C _1-6 alkoxy group, more preferably a linear or branched chain C _{1- 4} alkoxy. Examples of the substituted amino group include an N-mono or disubstituted amino group substituted with the above alkyl group, cycloalkyl group, aryl group, aralkyl group, fluorenyl group or the like. Among these substituents, an alkyl group, an aryl group, an alkoxy group, a hydroxyl group or the like is preferred from the viewpoint of improving the durability of the adhesive composition. Further, when the decane compound (A) contains a polar group (particularly a hydroxyl group) such as an alkoxy group or a hydroxyl group, since an optimum crosslinked structure capable of exhibiting good durability can be formed, an adhesive layer having high durability can be obtained. .

The structural units (a1) to (a4) constituting the decane compound (A) may be appropriately selected depending on the shape of the decane compound (A), and the decane compound (A) may contain the structural unit (a1) alone or in combination of two or more. (a4). For example, when the structure of the decane compound (A) is linear, the decane compound (A) has a structure represented by the above formula (a2), and the ruthenium atoms have a structure in which they are linearly bonded. In the case of a cyclic structure, the decane compound (A) has three or more structural units (a2), and the ruthenium atoms have a structure in which they are bonded in a ring shape. In the case of a mesh (or a network), the decane compound (A) contains a structural unit (a3) and/or (a4), and the ruthenium atoms have a structure in which they are combined into a mesh.

The number of the repeating units of the structural units (a1) to (a4) can be appropriately selected depending on the shape or molecular weight of the polydecane compound, and the number of repeating units of the structural units (a1) to (a4) is preferably 2 to 200. Preferably, it is from 3 to 150, more preferably from 5 to 120, and particularly preferably from 7 to 100. Further, the number of overlapping units of each structural unit is two or more, and the types of the substituents (R ¹ to R ⁶ ) may be the same or different between the structural units.

In a preferred embodiment, the decane compound (A) is a network-like polydecane compound mainly composed of a structural unit (a3) from the viewpoint of durability of the adhesive layer. In the decane compound (A), the ratio of the structural unit (a3) is preferably 70 mol% or more based on the total molar amount of the total constituent unit contained in the decane compound (A), preferably 80% or more, more preferably 90% or more. When the ratio of the structural unit (a3) is at least the lower limit value, the decane compound (A) can form a three-dimensional mesh structure which is advantageous for durability.

In a preferred aspect, the decane compound (A) has a structural unit (a3) and a structural unit (a1) and/or a structural unit (a2), and more preferably has a structural unit (a3) and a structural unit ( A mesh) polyalkylene compound. In this way, the adhesive layer can exhibit good durability even in a high temperature environment.

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

In the mesh-like polydecane compound having the structural unit (a3) and the structural unit (a2), R ⁴ and R ^{5 of the} desired structural unit (a2) are selected from the viewpoint of durability improvement. An alkyl group (ideally a C _1-4 alkyl group), an aryl group (ideally a C _6-10 aryl group), and a hydroxyl group, and R ^{6 of the} desired structural unit (a3) is selected from a respective alkyl group. (ideally, a C _1-4 alkyl group), an aryl group (ideally a C _6-10 aryl group), and a hydroxyl group. The molar ratio of the aryl group to the alkyl group (aryl/alkyl group) contained in the mesh-like polydecane compound is preferably from 1 to 15, more preferably from 1.5 to 12, still more preferably from 2 to 11. . When the molar ratio is in the above range, the durability of the adhesive layer can be further improved.

As a representative example of the decane compound (A) (preferably, the mesh-like decane compound (A)), a polydecane compound in which R ⁶ is a structural unit (a3) of an alkyl group, for example, R may be mentioned. ⁶ is a polydecane compound of a structural unit (a3) wherein a methyl group is a structural unit (a3) wherein R ⁶ is an ethyl group; a polydecane compound having a structural unit (a3) wherein R ⁶ is an aryl group (particularly a phenyl group); a polydecane compound having a structural unit (a3) wherein R ⁶ is an alkyl group (particularly a methyl group) and a structural unit (a3) wherein R ⁶ is an aryl group (particularly a phenyl group); and R ⁴ is an alkyl group (particularly Methyl) and R ⁵ are a structural unit (a2) of an aryl group (particularly a phenyl group), a polydecane compound having a structural unit (a3) wherein R ⁶ is an aryl group (particularly a phenyl group); and R ⁴ is an alkane a structural unit (a2) in which an aryl group (particularly a phenyl group) and R ⁵ are an aryl group (particularly a phenyl group), and a structure in which R ⁶ is an alkyl group (particularly a methyl group) or an aryl group (particularly a phenyl group) a polydecane compound of the unit (a3); a structural unit (a2) wherein R ⁴ and R ⁵ are each an alkyl group (particularly a methyl group), and R ⁶ is an alkyl group (particularly a methyl group) or an aryl group (particularly It is phenyl) structural unit (a3) an alkoxy compound of silicon polyethylene; and R ⁴ have R ⁵ is a structural unit (a2) of an aryl group (particularly a phenyl group), and a polydecane which is 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 compound; in the above-mentioned networked decane compound (A), a part of R ⁴ to R ⁶ is a decane compound substituted with a hydroxyl group or the like. Among them, from the viewpoint of the durability of the adhesive layer, the polyalkylene compound having the structural unit (a2) and the structural unit (a3) exemplified above is preferred. These decane compounds (A) may be used singly or in combination of two or more.

The lower limit of the weight average molecular weight (Mw) of the decane compound (A) is preferably 300 or more, preferably 500 or more, in terms of standard polystyrene by gel permeation chromatography (GPC). More preferably, it is 700 or more, and particularly preferably 1000 or more.

Further, the upper limit of the weight average molecular weight (Mw) of the decane 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 decane compound (A) may be any combination of the above upper limit value and the above lower limit value, and is preferably 300 to 100,000, preferably 500 to 50,000, more preferably 700. To 30,000, the best is 1000 to 20,000. When Mw is in the above range, it can exhibit good durability even in a high-temperature environment (for example, an environment of 100 ° C or higher). Further, 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, more preferably 1.0 to 2.0.

As a method of producing the decane compound (A), a conventional method, a method of dehalogenation polymerization in the presence of an alkali metal, and a halogenated decane corresponding to each structural unit may be mentioned. In addition, as a commercial item of the decane compound (A), for example, Ogssol SI-10-10, SI-10-20, SI-20-10, SI-30- manufactured by Osaka Gas Chemical Co., Ltd. 10 and so on.

The ratio of the decane compound (A) is preferably from 0.01 to 10% by mass, preferably from 0.1 to 5% by mass, more preferably from 0.5 to 3%, based on the total amount of the solid content of the adhesive composition of 100% by mass. The mass %, particularly preferably 0.7 to 2% by mass. When the ratio of the decane compound (A) is within the above range, it is advantageous to improve the durability of the adhesive layer.

The ratio of the decane compound (A) to the case where the adhesive composition contains a polymer (for example, a (meth)acrylic resin (B) to be described later), and the polymer (for example, relative to the (meth)acrylic acid described later) The resin (B)) is 100 parts by mass, preferably 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, particularly preferably 0.7 to 2 parts by mass. When the ratio of the decane compound (A) is in the above range, it is advantageous to improve the durability of the adhesive layer.

Since the adhesive composition of the present invention contains the Si-Si-bonded decane compound (A), the composition of the adhesive can be improved even in a high-temperature environment (for example, a high-temperature environment of 100 ° C or higher). The durability of the adhesive layer can effectively suppress the peeling (or floating) of the interface, foaming and agglutination damage. It is presumed that these are the components of the decane compound (A) contained in the adhesive composition (for example, a polymer such as a (meth)acrylic resin (B) to be described later), and the cohesive force and the like can be improved.

In the present specification, the durability means, for example, in a high-temperature environment, in a high-temperature and high-humidity environment, in an environment of high temperature and low temperature, etc., at the interface between the adhesive layer and the adjacent optical members. It is possible to suppress the characteristics of floating or peeling (there is a case called peeling resistance), and it is possible to suppress unsuitable characteristics such as foaming of the adhesive layer (there is a case called anti-foaming property). Further, in the present specification, the agglomeration resistance is a property of suppressing aggregation failure (or tearing) of the adhesive layer.

The adhesive composition of the present invention may further contain a (meth)acrylic resin (B), a crosslinking agent (C), and a Si-Si-bonded decane compound (D).

[1-2] (meth)acrylic resin (B)

The (meth)acrylic resin (B) is preferably a structural unit derived from a (meth)acrylic monovalent body, based on 100% by mass of the total structural unit constituting the (meth)acrylic resin (B). It is contained in a polymer or a copolymer of 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more. In addition, in the present specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid, and "(meth)acrylate" or "(meth)acryloyl group" means acrylate, respectively. Or methacrylate, acryl thiol or methacryl fluorenyl.

The (meth)acrylic resin (B) may contain, for example, a structural unit derived from a (meth) acrylate containing a polar group, a structural unit derived from a (meth) acrylamide-based monomer, and a source. a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer, a structural unit derived from a plurality of (meth)acryl fluorenyl monomers in a molecule, and a structural unit derived from an aryl acrylate A structural unit derived from an alkyl acrylate, a structural unit derived from an alkyl acrylate containing a substituent, and the like. These structural units may be used singly or in combination of two or more.

Examples of the (meth) acrylate containing a polar group include a (meth) acrylate containing a hydroxyl group, a (meth) acrylate containing a heterocyclic group such as an epoxy group, and a substituted or unsubstituted amine. The (meth) acrylate, the (meth) acrylate containing a carboxyl group, the (meth) acrylate containing an ethyl fluorenyl group, and the like.

The hydroxyl group-containing (meth) acrylate is preferably a hydroxyl group-containing (meth) acrylate represented by the following formula (b1) or (b2).

(wherein, 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 substituent may be the same or Can be different)

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

In the formula (b1) and the formula (b2), X ¹ and X ^{2 each} represent a methylene group which may have a substituent. As the substituent, for example, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom) or an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a secondary group) may be mentioned. a C _1-10 alkyl group of a butyl group, a tertiary butyl group, a pentyl group, a hexyl group or the like, preferably a C _1-6 alkyl group, more preferably a C _1-3 alkyl group, or a cycloalkyl group (for example, a ring) a C _5-8 cycloalkyl group such as a pentyl group or a cyclohexyl group, an aryl group (for example, an alkylphenyl group (tolyl, xylyl group, etc.), a C _6-12 aryl group such as a phenyl group), or an aralkyl group ( For example, a C _7-14 aralkyl group such as a benzyl group, an alkoxy group (for example, a C _1-4 alkoxy group such as a methoxy group or an ethoxy group), or a polyoxyalkylene group (for example, a dioxyethylene group). a cycloalkoxy group (for example, a C _5-10 cycloalkoxy group such as a cyclohexyloxy group), an aryloxy group (for example, a C _6-12 aryloxy group such as a phenoxy group), or an aralkyloxy group ( For example, a C _7-14 aralkyloxy group such as a benzyloxy group, an alkylthio group (for example, a C _1-4 alkylthio group such as a methylthio group or an ethylthio group), a cycloalkylthio group (for example, a ring). a C _5-8 cycloalkylthio group such as a hexylthio group, an arylthio group (for example, a C _6-12 arylthio group such as a thiophenoxy group), an aralkylthio group (for example, a benzylthio group or the like). C _7-14 An aralkylthio group, a fluorenyl group (for example, a C _2-7 fluorenyl group such as an ethenyl group), a nitro group, a cyano group or the like. Among them, a halogen atom, an alkyl group, an alkoxy group, and an aryloxy group are preferred, and an alkyl group is more preferred.

A ¹ and A ² each independently represent a hydrogen atom or an alkyl group, and the alkyl group is an alkyl group exemplified in X ¹ and X ² , and is preferably a methyl group.

In the formula (b1), n represents an integer of 1 to 4, desirably an integer of 1 to 3, more preferably 2. Further, in the formula (b2), m represents an integer of 5 or more. m, usually an integer of 5 to 20, desirably 5 to 15, preferably 5 to 11 integers, more preferably an integer of 5 to 9, more preferably an integer of 5 to 7, particularly preferably It is 5.

Specific examples of the hydroxyl group-containing (meth) acrylate (b1) include 1-hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, and (meth)acrylic acid 1. -Hydroxyheptyl, 1-hydroxybutyl (meth) acrylate, 1-hydroxy C _1-8 alkyl (meth) acrylate such as 1-hydroxypentyl (meth)acrylate; (meth)acrylic acid 2 -hydroxyethyl ester, 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; 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, (A) 3-hydroxy C _3-10 alkyl (meth)acrylate, such as 3-hydroxyhexyl acrylate, 3-hydroxyheptyl (meth)acrylate; 4-hydroxybutyl (meth) acrylate, (methyl) (4-hydroxypentyl acrylate, 4-hydroxyhexyl (meth) acrylate, 4-hydroxyheptyl (meth) acrylate, 4-hydroxyoctyl (meth) acrylate, 4-hydroxy (meth) acrylate C _4-11 alkyl acrylate; (meth) acrylate, 2-chloro-2-hydroxypropyl (meth) acrylate, 3-chloro-2- Group, propyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate and the like. Among them, from the viewpoint of durability, n such as 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, or 2-hydroxybutyl (meth)acrylate is a hydroxyl group-containing (methyl group). Acrylate; 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, etc. n is 3 hydroxyl-containing (meth) acrylate It is better. In particular, a hydroxyl group-containing (meth) acrylate wherein n is 2 is preferable, and 2-hydroxyethyl (meth)acrylate is also more preferable.

Specific examples of the hydroxyl group-containing (meth) acrylate (b2) include 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, and (meth)acrylic acid 5- 5-hydroxy C _5-12 alkyl (meth)acrylate, such as hydroxyheptyl ester, 5-hydroxyoctyl (meth)acrylate, 5-hydroxydecyl (meth)acrylate; 6-hydroxyl (meth)acrylate Hexyl ester, 6-hydroxyheptyl (meth)acrylate, 6-hydroxyoctyl (meth)acrylate, 6-hydroxydecyl (meth)acrylate, 6-hydroxydecyl (meth)acrylate, etc. 6-hydroxy C _6-13 alkyl acrylate; 7-hydroxyheptyl (meth) acrylate, 7-hydroxyoctyl (meth) acrylate, 7-hydroxy decyl (meth) acrylate, (methyl) 7-hydroxy C _7-14 alkyl (meth)acrylate, such as 7-hydroxydecyl acrylate or 7-hydroxyundecyl (meth)acrylate; 8-hydroxyoctyl (meth)acrylate, (methyl) (Methyl hydroxy decyl acrylate, 8-hydroxy decyl (meth) acrylate, 8-hydroxyundecyl (meth) acrylate, 8-hydroxydodecyl (meth) acrylate, etc. (methyl) 8-hydroxy C _8-15 alkyl acrylate; 9-hydroxy decyl (meth) acrylate, (meth) acrylate 9 (meth)acrylic acid such as hydroxy oxime ester, 9-hydroxyundecyl (meth) acrylate, 9-hydroxydodecyl (meth) acrylate, 9-hydroxytridecyl (meth) acrylate 9-hydroxy C _9-16 alkyl ester; 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, acrylic acid 10- 10-hydroxy C _10-17 alkyl (meth)acrylate, such as hydroxytridecyl ester, 10-hydroxytetradecane (meth)acrylate; 11-hydroxyundecyl (meth)acrylate, (methyl) ) 11-hydroxydodecyl acrylate, 11-hydroxytridecyl (meth)acrylate, 11-hydroxytetradecyl (meth)acrylate, 11-hydroxypentadecyl (meth)acrylate, etc. 10-hydroxy C _11-18 alkyl (meth)acrylate; 12-hydroxydodecyl (meth)acrylate, 12-hydroxytridecyl (meth)acrylate, 12-hydroxyl (meth)acrylate 12-hydroxy C _12-19 alkyl (meth) acrylate such as tetraalkyl ester; 13-hydroxypentadecyl (meth)acrylate, 13-hydroxytetradecyl (meth)acrylate, (methyl) ) acrylate, 13-hydroxy esters such as pentadecyl (meth) acrylic acid C _13-20 alkyl esters of 13-hydroxy (Meth) acrylate, 14-hydroxy myristyl (meth) acrylate, 14-hydroxy esters such as pentadecyl (meth) acrylate, 14- hydroxy C _14-21 alkyl acrylate; (meth) acrylate, 15-hydroxy A 15-hydroxy C _15-22 alkyl (meth)acrylate such as pentadecyl ester or 15-hydroxyhexadecane (meth)acrylate. Among them, from the viewpoint of durability, 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, (meth)acrylic acid 5 A (meth) acrylate having a hydroxyl group of m such as hydroxyoctyl ester or 5-hydroxy decyl (meth)acrylate is preferable, and 5-hydroxypentyl (meth)acrylate is more preferable.

The (meth) acrylate (b3) containing an ethyl acetonitrile group may contain a substituent other than the acetamidine group, and examples of the substituent include a cyano group. Specific examples of the (meth) acrylate (b3) containing an ethyl acetonitrile group include acetoxyethyl (meth) acrylate and acetoxypropyl propyl group (A). Ethyl acetoxy C _2-10 alkyl (meth) acrylate such as acrylate, acetamyl butyl methacrylate or the like; 2-cyanoacetoxycarbonyl A cyanoacetoxy C _2-10 alkyl (meth) acrylate such as ethyl (meth) acrylate. Among them, from the viewpoint of the durability of the adhesive layer, acetoxyethyl (meth) acrylate, acetamyl propyl (meth) acrylate, acetonitrile The butyl (meth) acrylate is preferred, and 2-ethyl acetoxyethyl (meth) acrylate is more preferred. These (meth) acrylate (b3) containing an ethyl acetonitrile group may be used alone or in combination of two or more.

When the (meth)acrylic resin (B) contains a structural unit derived from a (meth) acrylate of a polar group, even when an adhesive composition is used for a transparent electrode such as ITO (tin-doped indium oxide), It can show good durability in high temperature environments. When such a (meth)acrylic resin (B) is contained in the adhesive composition, it is estimated that the most suitable crosslinking can be formed in the appearance of good durability by the influence of the highly reactive polar group. Structure or adhesive layer with crosslink density.

In a preferred embodiment, the (meth)acrylic resin (B) is a structural unit selected from the group consisting of a hydroxyl group-containing (meth) acrylate represented by the above formula (b1), and having the above formula ( B2) at least one of a structural unit derived from a hydroxyl group-containing (meth) acrylate and a structural unit derived from an ethyl ketone group-containing (meth) acrylate (b3). In this aspect, the durability of the adhesive layer formed of the adhesive composition can be further improved. In a particularly preferred aspect, the (meth)acrylic resin (B) contains a structural unit derived from a hydroxyl group-containing (meth) acrylate (b1), and is derived from a hydroxyl group-containing (meth)acrylic acid. The structural unit of the ester (b2) is a structural unit derived from a (meth) acrylate (b3) containing an ethyl acetonitrile group.

In this aspect, the (meth)acrylic resin is a hydroxyalkyl group having a chain length (n and m) of a different carbon atom, or a hydroxyalkyl group and an ethyl acetyl group in the side chain, since this is advantageous. The optimum cross-linking structure is formed, so that the peeling (or floating) of the interface, the agglomeration damage, and the blistering can be more effectively suppressed in a high-temperature environment, and the durability of the adhesive layer formed by the adhesive composition may become more For improvement.

The ratio of the structural unit derived from the hydroxyl group-containing (meth) acrylate represented by the above formula (b1) is preferably 1.5 to 10 with respect to 100 parts by mass of the total structural unit constituting the (meth)acrylic resin. The parts by mass are more preferably 2 to 8 parts by mass.

The ratio of the structural unit derived from the hydroxyl group-containing (meth) acrylate or the ethyl methacrylate-containing (meth) acrylate represented by the above formula (b2) to the constituent (methyl) The total structural unit of the acrylic resin is 100 parts by mass, preferably 0.1 to 8 parts by mass, more preferably 0.25 to 3 parts by mass.

The structural unit derived from the hydroxyl group-containing (meth) acrylate represented by the formula (b1) and the structural unit derived from the hydroxyl group-containing (meth) acrylate represented by the formula (b2) or derived from the The ratio (mass ratio) of the structural unit of the (meth) acrylate (b3) of the ethyl acetonitrile group is not particularly limited as long as it is within the above range, but it is preferably (b1)/(b2 or b3). ) = 14 to 1, preferably 13 to 1, more preferably 11 to 1, and particularly preferably 9 to 1. When it is in the above range, the durability of the adhesive layer can be further improved.

Examples of the (meth) acrylate containing a heterocyclic group include acryloyl morpholine, vinyl caprolactam, N-vinyl-2-pyrrolidone, vinyl pyridine, and tetrahydrogen (meth) acrylate. Mercaptoester, caprolactone modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran Wait. Examples of the (meth) acrylate having a substituted or unsubstituted amino group include aminoethyl (meth) acrylate and N,N-dimethylaminoethyl (meth) acrylate. Dimethylaminopropyl (meth)acrylate or the like. Examples of the (meth) acrylate having a carboxyl group include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and carboxyalkyl (meth)acrylate (for example, (A) Base) carboxyethyl acrylate, carboxypentyl (meth) acrylate, and the like. These (meth) acrylates can be used singly or in combination of two or more. Further, from the viewpoint of preventing the peeling property of the separator which may be laminated in the adhesive layer, it is preferable that the monomer structural unit derived from the amine group is not contained. When it is substantially not contained, it is less than 1.0 part by mass based on 100 parts by mass of the total structural unit constituting the (meth)acrylic resin (B).

When the adhesive composition contains a structural unit derived from a carboxyl group-containing (meth) acrylate, it exhibits excellent durability, but is considered to increase corrosion of a transparent electrode such as ITO. The adhesive composition of the present invention can further improve durability as long as it contains a small amount of a structural unit derived from a carboxyl group-containing (meth) acrylate to a degree that does not corrode a transparent electrode such as ITO.

Therefore, in the adhesive composition of the present invention, a small amount of a structural unit derived from a carboxyl group-containing (meth) acrylate may have both durability and resistance to transparent electrode corrosion (ITO corrosion resistance). Opposite characteristics.

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

Examples of the (meth) acrylamide-based monomer include N-methylol acrylamide, N-(2-hydroxyethyl) acrylamide, and N-(3-hydroxypropyl) acrylamide. , N-(4-hydroxybutyl) acrylamide, N-(5-hydroxypentyl) acrylamide, N-(6-hydroxyhexyl) acrylamide, N,N-dimethyl decylamine, N,N-diethyl acrylamide, N-isopropyl acrylamide, N-(3-dimethylaminopropyl) acrylamide, N-(1,1-dimethyl-3- Oxybutyl) acrylamide, N-[2-(2-oxo-1-imidazolidinyl)ethyl]propenylamine, 2-propenylamino-2-methyl-1-propane sulfonic acid, N-(methoxymethyl)propenylamine, N-(ethoxymethyl)propenylamine, N-(propoxymethyl)propenylamine, N-(1-methylethoxymethyl) Acrylamide, N-(1-methylpropoxymethyl)propenylamine, N-(2-methylpropoxymethyl)propenylamine [alias: N-(isobutoxy A) Acrylamide, N-(butoxymethyl)propenylamine, N-(1,1-dimethylethoxymethyl)propenylamine, N-(2-methoxyethyl Acrylamide, N-(2-ethoxyethyl)propenylamine, N-(2-propoxyethyl)propenylamine, N-[2-(1-methyl) Oxy)ethyl]propenylamine, N-[2-(1-methylpropoxy)ethyl]propenylamine, N-[2-(2-methylpropoxy)ethyl]propene oxime Amine [alias: N-(2-isobutoxyethyl) acrylamide], N-(2-butoxyethyl) acrylamide, N-[2-(1,1-dimethyl B) Oxy)ethyl]propenylamine or the like. The durability of the adhesive layer containing the structural unit derived from the (meth)acrylamide monomer can be further enhanced. Particularly, among them, N-(methoxymethyl) acrylamide, N-(ethoxymethyl) acrylamide, N-(propoxymethyl) acrylamide, N-(butoxy Methyl) acrylamide and N-(2-methylpropoxymethyl) acrylamide are preferred.

The ratio of the structural unit derived from the (meth)acrylamide monomer is preferably 5 parts by mass or less based on 100 parts by mass of the total structural unit constituting the (meth)acrylic resin. The upper limit of the ratio of the structural unit derived from the (meth)acrylamide monomer is preferably 3 parts by mass, preferably 2 parts by mass, more preferably 1 part by mass. The lower limit of the ratio of the structural unit derived from the (meth)acrylamide monomer is preferably 0 parts by mass, preferably 0.001 part by mass, more preferably 0.01 part by mass, and particularly preferably 0.1 part by mass. Share. The ratio of the structural unit derived from the (meth)acrylamide monomer may be arbitrarily combined with the upper limit and the lower limit, for example, 0 to 5 parts by mass, preferably 0.001 to 3 parts by mass, preferably It is 0.01 to 2 parts by mass, more preferably 0.1 to 1 part by mass. When the ratio of the structural unit derived from the (meth)acrylamide monomer is within the above range, the durability of the adhesive layer can be further improved. Further, when it is at most the above upper limit value, the storage stability of the (meth)acrylic resin (B) can be improved.

As the styrene monomer, styrene; methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl may be mentioned. Alkyl styrene such as styrene, butyl styrene, hexyl styrene, heptyl styrene or octyl styrene; fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodine styrene, etc. Halogenated styrene; nitrostyrene; ethoxylated styrene; methoxystyrene; divinylbenzene.

Examples of the vinyl monomer include vinyl acetate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, and the like; vinyl chloride; ethylene bromide; Ethylene halide; vinylidene halide such as vinylidene chloride; nitrogen-containing aromatic vinyl such as vinyl pyridine, vinyl pyrrolidone or vinyl carbazole; butadiene, isoprene, chloroprene, etc. Conjugated diene monomer; unsaturated nitrile such as acrylonitrile or methacrylonitrile.

Examples of the monomer having a plurality of (meth) acrylonitrile groups in the molecule include 1,4-butanediol di(meth)acrylate and 1,6-hexanediol di(meth)acrylic acid. Ester, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylic acid a monomer having two (meth) acrylonitrile groups in the molecule such as ester or tripropylene glycol di(meth)acrylate; and three molecules in the molecule such as trimethylolpropane tri(meth)acrylate A monomer of (meth)acrylonitrile group or the like.

Examples of the aryl acrylate include C _6-12 aryl acrylate such as phenyl acrylate or naphthyl acrylate.

As the alkyl acrylate, the glass transition temperature (Tg) of the homopolymer is an alkyl acrylate (b4) of less than 0 ° C, and the Tg of the homopolymer is an alkyl acrylate of 0 ° C or more ( B5) and so on.

The glass transition temperature (Tg) of the homopolymer is an alkyl acrylate (b4) which is less than 0 ° C, and examples thereof include ethyl acrylate, n- and i-propyl acrylate, n- and i-butyl. Acrylate, n-pentyl acrylate, n- and i-hexyl acrylate, n-heptyl acrylate, n- and i-octyl acrylate, 2-ethylhexyl acrylate, n- and i- A linear or branched chain alkyl acrylate having an alkyl group having from 2 to 12 alkyl groups, such as a mercapto acrylate, an n- and i-mercapto acrylate, or an n-dodecyl acrylate. The alkyl acrylate (b4) may have an alicyclic alkyl acrylate (cycloalkyl acrylate), but the number of carbon atoms is from the viewpoint of flexibility or adhesion to an optical film. a linear or branched chain alkyl acrylate of 2 to 10 is preferred, and a linear or branched chain alkyl acrylate having 3 to 8 carbon atoms is preferred, and the number of carbon atoms is 4 to 6. A linear or branched chain alkyl acrylate is more preferred, and n-butyl alkyl acrylate is particularly preferred. When n-butylalkyl acrylate is used, the subsequentity can be improved, for example, it is advantageous for peeling resistance and the like. These alkyl acrylates (b4) can be used individually or in combination of 2 or more types.

Examples of the alkyl acrylate (b5) in which the Tg of the homopolymer is 0 ° C or higher include methacrylate, cycloalkyl acrylate (for example, cyclohexyl acrylate, isobornyl acrylate), and stearin. A acrylate, a tertiary butyl acrylate or the like is particularly preferred as a methacrylate. When methacrylate is used, the strength can be increased, for example, it is advantageous for agglomeration damage. These alkyl acrylates (b5) can be used individually or in combination of 2 or more types. Further, the Tg of the homopolymer of the alkyl acrylate can be referred to, for example, a literature value of a Polymer Handbook (Wiley-Interscience).

The (meth)acrylic resin (B) has a structure derived from an alkyl acrylate (b4) in which the glass transition temperature of the homopolymer is less than 0 ° C from the viewpoint of improving the durability of the adhesive layer. The unit is preferably a structural unit derived from an alkyl acrylate (b5) having a glass transition temperature of 0 ° C or more. The Tg of the homopolymer is an alkyl acrylate of less than 0 ° C, and when the Tg of the homopolymer is 0 ° C or more, the anti-agglomeration, anti-foaming property and peeling resistance can be achieved in parallel. The durability against dimensional changes of an optical film such as a polarizing plate can be improved.

The ratio of the structural unit derived from the alkyl acrylate in the (meth)acrylic resin (B) is relative to the constituent (meth)acrylic resin from the viewpoint of durability and reworkability of the adhesive layer ( 100 parts by mass of the total structural unit of B), for example, 40 parts by mass or more (for example, 50 to 98 parts by mass), desirably 60 parts by mass or more (for example, 70 to 95 parts by mass), more preferably 70 parts by mass. Above (for example 80 to 90 parts by mass).

The glass transition temperature derived from the homopolymer is a structural unit of the alkyl acrylate (b4) which is less than 0 ° C, and the mass ratio of the structural unit derived from the alkyl acrylate (b5) having a glass transition temperature of 0 ° C or higher (b4) / (b5), desirably 0.1 to 10, preferably 0.2 to 5, more preferably 0.3 to 3.5. When it is within the above range, durability can be further improved.

The higher the ratio of the structural unit derived from the alkyl acrylate (b4) having a glass transition temperature of less than 0 ° C, the subsequentity is improved. The larger the ratio of the structural unit derived from the alkyl acrylate (b5) having a glass transition temperature of 0 ° C or higher, the higher the anti-aggregation destructive property.

As the alkyl acrylate having a substituent, in the above alkyl acrylate, the hydrogen atom of the alkyl group is an alkyl acrylate substituted by a substituent. The substituent may, for example, be an aryl group (such as a phenyl group), an aryloxy group (phenoxy group) or an alkoxy group (for example, a methoxy group or an ethoxy group). Examples of the alkyl acrylate having a substituent include an alkoxyalkyl acrylate (for example, 2-methoxyethyl acrylate or ethoxy methacrylate) and an arylalkyl acrylate (for example). For example, benzyl acrylate or the like, aryloxyalkyl acrylate (for example, phenoxyethyl acrylate, etc.), aryloxy polyalkylene glycol monoacrylate, polyalkylene glycol monoacrylate, etc. . These alkyl acrylates can be used singly or in combination of two or more. An aryl group or a benzyl group or an alkyl acrylate having an aromatic ring such as an aryloxy group can improve the white point of the polarizing plate in the durability test. Further, an alkoxy group or an aryloxy group can enhance the antistatic property when an antistatic agent is added to the adhesive layer. The alkylene group of the aryloxy polyalkylene glycol monoacrylate and the polyalkylene glycol monoacrylate may, for example, be a C _1-6 alkylene group such as a methylene group, an ethylene group or a propylene group. The unit of the oxyalkylene group, such as an ethylene group (ideally, an ethylene group or the like), is, for example, 1 to 7, from the viewpoint of the balance between the durability and the antistatic property of the adhesive layer formed of the adhesive composition. Ideally 1 to 5 (especially 1 to 2). Specific examples thereof include phenoxy diethylene glycol acrylate such as phenoxy di- or seven-C _1-3 alkylene glycol acrylate, diethylene glycol monoacrylate, and the like. _1-3 alkylene monoacrylate and the like. As the substituted alkyl acrylate used in the present invention, phenoxyethyl acrylate and phenoxy diethylene glycol acrylate are used from the viewpoint of balance of durability, white spot resistance and antistatic property. It is especially good.

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

The (meth)acrylic resin (B) has a weight average molecular weight (Mw) in terms of standard polystyrene by gel permeation chromatography GPC, and is 1 million in order to improve the durability of the adhesive layer. The above is better. The lower limit of Mw is preferably 1.1 million, more preferably 1.2 million, and particularly good is 1.25 million. In addition, although the upper limit of the Mw is not particularly limited, it is preferably 2.5 million in terms of coatability when the adhesive composition is processed into a film shape (coated on a substrate). The best is 2.2 million, and the better is 2 million. Mw may also be an upper limit and a lower limit of any combination, and may be, for example, 100 to 2.5 million, preferably 1.1 to 2.2 million, more preferably 1 to 2,000,000. Further, 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, more preferably 3 to 6.

Further, the (meth)acrylic resin (B) preferably has a single peak in the range of 1.0 × 10 ³ to 2.5 × 10 ⁶ in the GPC discharge curve. When the (meth)acrylic resin (B) having the number of peaks of 1 is used, it is advantageous to improve the durability of the adhesive layer.

In the above range of the obtained discharge curve, "having a single peak" means that there is only one maximum value in the range of Mw 1.0 × 10 ³ to 2.5 × 10 ⁶ . In the present specification, in the GPC discharge curve, the S/N ratio is defined as a peak of 30 or more. Further, the number of peaks of the GPC discharge curve and the Mw and Mn of the (meth)acrylic resin (B) can be determined by the GPC measurement conditions described in the examples.

(meth)acrylic resin (B) is a viscosity at 25 ° C when it is dissolved in ethyl acetate to prepare a solution having a concentration of 20% by mass, at 20 Pa. The following is better, from 0.1 to 15Pa. s is better. In the viscosity of this range, it is advantageous from the viewpoint of coatability when the adhesive composition is applied to the substrate. Also, the viscosity can be measured by a Brookfield rotary viscometer.

The glass transition temperature (Tg) of the (meth)acrylic resin (B) may be, for example, -60 to 10 ° C, preferably -50 to 5 ° C, preferably -40 to -5 ° C, particularly preferably It is -40 to -10 °C. When Tg is less than the upper limit, it is advantageous for improving the wettability of the substrate to be adhered to the adhesive layer, and when it is at or below the lower limit, it is advantageous for improving the durability of the adhesive layer. Also, the glass transition temperature can be measured by a differential scanning calorimeter (DSC).

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

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like is used. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-propyl) ketone and the like. As the thermal polymerization initiator, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis (ring) Hexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxy An azo compound such as valeronitrile), dimethyl-2,2'-azobis(2-methylpropionate) or 2,2'-azobis(2-hydroxymethylpropionitrile); Laurel, peroxide, tertiary-butyl hydroperoxide, benzammonium peroxide, tertiary butyl peroxybenzoate, cumene hydroperoxide, diisopropylperoxydicarboxylate, Organic esters of dipropyl peroxydicarboxylate, tertiary butyl peroxy neodecanoate, tertiary butyl peroxypivalate, (3,5,5-trimethylhexyl) peroxide Peroxide; inorganic peroxide such as potassium persulfate, ammonium persulfate or hydrogen peroxide. Further, a redox initiator such as a peroxide or a reductant may be used in combination.

The ratio of the polymerization initiator is about 0.001 to 5 parts by mass based on 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 an active energy ray (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; and aliphatic alcohols such as propanol and isopropanol; acetone and methyl ethyl Ketones such as ketones and methyl isobutyl ketones.

[1-3] Crosslinking agent (C)

The adhesive composition may contain a crosslinking agent (C). The crosslinking agent (C) is reacted with a polar group (for example, a hydroxyl group, an ethyl acetyl group, an amine group, a carboxyl group, or the like) in the (meth)acrylic resin (B). The crosslinking agent (C) is a crosslinked structure which forms a crosslinked structure with a (meth)acrylic resin or the like, and is advantageous in forming durability or workability.

Examples of the crosslinking agent (C) include a conventional crosslinking agent (for example, an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, a peroxide, etc.), particularly from an adhesive composition. The isocyanate-based compound is preferred from the viewpoints of the pot life of the adhesive layer, the durability of the adhesive layer, and the crosslinking speed.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, and examples thereof include an aliphatic isocyanate compound (for example, hexamethylene diisocyanate) and an alicyclic isocyanate. a compound (for example, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate) or an aromatic isocyanate compound (for example, toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, Naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). Further, the crosslinking agent (C) may be an adduct with a polyol compound of the above isocyanate compound [for example, by addition of glycerin, trimethylolpropane or the like], an isocyanurate compound. , an amine ester prepolymer type isocyanate compound, a biuret type compound, a polyether polyol, a polyester polyol, a propylene polyol, a polybutadiene polyol, a polyisoprene polyol, or the like Derivatives of etc. The crosslinking agent (C) may be used singly or in combination of two or more. In addition, the representative is exemplified by an aromatic isocyanate compound (for example, toluene diisocyanate, xylylene diisocyanate), an aliphatic isocyanate compound (for example, hexamethylene diisocyanate), or a polyol compound thereof ( For example, an addition of glycerin, trimethylolpropane, or a polyisocyanurate body. When the crosslinking agent (C) is passed through an aromatic isocyanate compound and/or such a polyol compound or an isocyanurate body, it is advantageous to form an optimum crosslinking density (or The crosslinked structure) can improve the durability of the adhesive layer. In particular, when the addition of the toluene diisocyanate compound and/or the polyol compound is performed, for example, the durability can be improved even when the adhesive layer is used in the transparent electrode.

The ratio of the crosslinking agent (C) is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass based on 100 parts by mass of the (meth)acrylic resin (B). It is more preferably 0.1 to 2 parts by mass, particularly preferably 0.2 to 1 part by mass, particularly preferably 0.25 to 0.8 parts by mass. When it is below the upper limit value, it is advantageous for the improvement of the followability (or peeling resistance), and when it is more than the lower limit value, it is advantageous for the anti-foaming property or the improvement of the processing.

[1-4] Si-Si-free decane compound (D)

The adhesive composition may contain a decane compound (D) which is not bonded with Si-Si. The adhesive composition can improve the adhesion (or adhesion) of the adhesive layer to the metal layer, the transparent electrode, the glass substrate, and the like by containing the decane compound (D). As the decane compound (D), a decane compound which may be bonded to a polar group (for example, a hydroxyl group, an ethyl acetyl group, an amine group, a carboxyl group or the like) of the (meth)acrylic resin (B) may be used. A decane compound having at least one alkoxy group in the molecule. Examples of the alkoxy group include C _1-6 such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a secondary-butoxy group, and a tertiary-butoxy group. The alkoxy group is preferably a methoxy group or an ethoxy group from the viewpoint of adhesion to a substrate (for example, a substrate).

As the decane compound (D), there may be mentioned vinyl trimethoxy decane, vinyl triethoxy decane, vinyl ginseng (2-methoxyethoxy) decane, and 3-glycidoxypropyl group. Trimethoxydecane, 3-glycidoxypropyltriethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 3-glycidoxypropylethoxylate Methyl decane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 3-chloropropylmethyldimethoxydecane, 3-chloropropyltrimethoxydecane, 3-methyl Acryloxypropyltrimethoxydecane, 3-mercaptopropyltrimethoxydecane, 1,3-bis(3'-trimethoxypropyl)urea, and the like.

Further, the decane compound (D) may be a ruthenium oligomer type compound, and when the oxime oligomer is represented by a combination of monomers, for example, it may be exemplified by containing 3-mercaptopropyldi or trimethoxy Alkane-tetramethoxynonane oligomer, 3-mercaptomethyldi or trimethoxydecane-tetraethoxydecane oligomer, 3-mercaptopropyldi or triethoxydecane-tetramethyl a mercaptoalkyl group-containing oligopolymer, a 3-decylmethyldi or a triethoxydecane-tetraethoxydecane oligomer, or the like; an oligopolymer containing the mercaptoalkyl group; A mercaptoalkyl group, an oligomer substituted in another substituent [3-glycidoxypropyl group, (meth)acryloxypropyl group, vinyl group, amine group, etc.].

The decane compound (D) may preferably be a decane compound represented by the following formula (d1). When the adhesive composition contains a decane compound represented by the following formula (d1), the adhesion (or adhesion) can be further improved, and an adhesive layer having good peeling resistance can be formed. In particular, in a high-temperature environment, even when an adhesive layer is used in a transparent electrode (or a laminate), adhesion (or adhesion) can be maintained, and high durability can be exhibited.

(wherein, B represents an alkylene group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and the above alkyl group and -CH ₂ - constituting the above alicyclic hydrocarbon group are also It may be substituted with -O- or -CO-, R ⁷ represents an alkyl group having 1 to 5 carbon atoms, and R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently, and represent a carbon number of 1 to 5. Alkyl or alkoxy with 1 to 5 carbon atoms)

In the formula (d1), B represents a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, a hepethylene group, an octamethylene group or the like having 1 to 20 carbon atoms. An alkanediyl group (ie, an alkylene group); a cyclobutylene group (eg, 1,2-cyclobutylene), a cyclopentylene group (eg, a 1,2-cyclopentylene group), a cyclohexylene group (eg, 1,2- a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms such as a cyclohexylene group or a cyclooctylene group (for example, 1,2-cyclooctylene group), or an alkylene group of the above-mentioned alicyclic group The -CH ₂ - group of the hydrocarbon group is a group substituted with -O- or -CO-. Desirable B represents an alkylene group having 1 to 10 carbon atoms (i.e., an alkanediyl group). 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, a secondary-butane group, a tertiary-butyl group or a pentyl group, and R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently, and represent an alkyl group having 1 to 5 carbon atoms exemplified in the above R ⁷ or a methoxy group, an ethoxy group, a propoxy group, or an i- group; An alkoxy group having 1 to 5 carbon atoms such as a propoxy group, a butoxy group, a secondary-butoxy group or a tertiary-butoxy group. Desirable R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently alkoxy groups having 1 to 5 carbon atoms. These decane compounds (D) may be used singly or in combination of two or more.

Specific examples of the decane compound represented by the above formula (d1) include (trimethoxydecylalkyl)methane, 1,2-bis(trimethoxydecylalkyl)ethane, and 1,2-double ( Triethoxynonyl)ethane, 1,3-bis(trimethoxydecyl)propane, 1,3-bis(triethoxydecyl)propane, 1,4-bis(trimethoxydecyl) Butane, 1,4-bis(triethoxydecyl)butane, 1,5-bis(trimethoxydecyl)pentane, 1,5-bis(triethoxydecyl)pentane 1,6-bis(trimethoxydecyl)hexane, 1,6-bis(triethoxydecyl)hexane, 1,6-bis(tripropoxydecyl)hexane, 1, Double (three C) of 8-bis(trimethoxydecyl)octane, 1,8-bis(triethoxydecyl)octane, 1,8-bis(tripropoxydecyl)octane, etc. _1-5 alkoxyalkylalkyl) C _1-10 alkane; bis(dimethoxymethyl decyl)methane, 1,2-bis(dimethoxymethyl decyl)ethane, 1,2- Bis(dimethoxyethyl decyl)ethane, 1,4-bis(dimethoxymethyl decyl) butane, 1,4-bis(dimethoxyethyl decyl) butane, 1,6-bis(dimethoxymethyldecyl)hexane, 1,6-bis (dimethoxy B) Silicon alkyl) hexane, 1,8-bis (dimethoxymethyl silicon alkyl) octane, 1,8-bis (silicon-dimethoxyethyl group) octane such as bis (C _1-5 Alkoxy C _1-5 alkyl fluorenyl) C _1-10 alkane; 1,6-bis(methoxydimethyl decyl) hexane, 1,8-bis(methoxy dimethyl decyl) a bis(mono C _1-5 alkoxy-diC _1-5 alkyl decylalkyl) C _1-10 alkane such as octane. Among them, 1,2-bis(trimethoxydecyl)ethane, 1,3-bis(trimethoxydecyl)propane, 1,4-bis(trimethoxydecyl)butane, 1,5 - bis (tri-C _1-3 ) of bis(trimethoxydecyl)pentane, 1,6-bis(trimethoxydecyl)hexane, 1,8-bis(trimethoxydecyl)octane, etc. Alkoxyalkylene)C _1-10 alkane is preferred, particularly preferably 1,6-bis(trimethoxydecyl)hexane or 1,8-bis(trimethoxydecyl)octane.

The ratio of the decane compound (D) is, for example, 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, preferably 0.05 to 3 parts by mass, per 100 parts by mass of the (meth)acrylic resin (B). More preferably, it is 0.1 to 1 part by mass, and particularly preferably 0.2 to 0.5 part by mass. When it is at most the above upper limit value, it is advantageous for suppressing the outflow of the decane compound (D) from the adhesive layer, and when the lower limit is satisfied, the adhesion of the adhesive layer to the metal layer or the glass substrate can be easily improved. (or follow-up), which is conducive to the improvement of peeling resistance.

[1-5]Antistatic agent (E)

The adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include a surfactant, a siloxane compound, a conductive polymer, and an ionic compound. An ionic compound is preferred from the viewpoint of improving the antistatic property of the adhesive (for example, suppressing an unsuitable phenomenon due to static electricity when peeling off the release film or the protective film). As the ionic compound, a compound which is conventionally used can be cited. Examples of the cationic component constituting the ionic compound include an organic cation, an inorganic cation, and the like. Examples of the organic cation include a pyridinium cation, an imidazolium cation, an ammonium cation, a phosphonium cation, a phosphonium cation, and the like. Examples of the inorganic cation include an alkali metal cation such as a lithium cation, a potassium cation, a sodium cation or a phosphonium cation, an alkaline earth metal cation such as a magnesium cation or a calcium cation, and the like. The anion component constituting the ionic compound may be any one of an inorganic anion and an organic anion. However, in terms of antistatic property, an anion component containing a fluorine atom is preferred. Examples of the anion component of the fluorine atom include a hexafluorophosphate anion (PF ₆ ^- ), a bis(trifluoromethanesulfonyl) quinone imine [(CF ₃ SO ₂ ) ₂ N ^- ], and a double (fluorothiol) quinone imine [(FSO ₂ ) ₂ N ^- ], tetrakis(pentafluorophenyl) borate anion [(C ₆ F ₅ ) ₄ B ^- ], and the like. These ionic compounds may be used singly or in combination of two or more. In particular, bis(trifluoromethanesulfonyl) anthracene anion [(CF ₃ SO ₂ ) ₂ N ^- ], bis(fluorothioindolyl) quinone anion [(FSO ₂ ) ₂ N ^- ], The tetrakis(pentafluorophenyl)borate anion [(C ₆ F ₅ ) ₄ B ^- ] is preferred.

From the viewpoint of stability over time of the antistatic property of the adhesive layer formed of the adhesive composition, a solid ionic compound is preferred at room temperature.

The ratio of the antistatic agent is, for example, 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 1 to 3 parts by mass, per 100 parts by mass of the (meth)acrylic resin (B).

In general, it is known that when an antistatic agent is contained in an adhesive, the durability of the adhesive layer is lowered, but the adhesive composition of the present invention exhibits excellent durability even in a high temperature environment even if it contains an antistatic agent. . Therefore, it is possible to obtain two opposing characteristics which have both good durability and antistatic properties.

[1-6] Other ingredients

The adhesive composition may contain two or more of the following additives: a solvent, a crosslinking catalyst, an ultraviolet absorber, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, An additive such as light-scattering fine particles. Further, an ultraviolet curable compound is blended in the adhesive composition to form an adhesive layer, which is then cured by irradiation with ultraviolet rays, and may be used as a harder adhesive layer. Examples of the cross-linking catalyst include hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, and isophoronediamine. An amine compound such as trimethylene diamine, polyamine resin or melamine resin.

The adhesive composition may contain a rust preventive agent from the viewpoint of improving the metal corrosion resistance of the adhesive layer. Examples of the rust inhibitor include a triazole compound such as a benzotriazole compound; a thiazole compound such as a benzothiazole compound; an imidazole compound such as a benzyl imidazole compound; an imidazoline compound; a porphyrin compound; a pyridine compound; a pyrimidine compound; an anthraquinone compound; an amine compound; a urea compound; a sodium benzoate; a benzyl fluorenyl compound; a di-secondary-butyl sulfide; Wait.

In an ideal aspect, the adhesive composition of the present invention is substantially free of a photopolymerization initiator and a decomposition product thereof. Thus, the photopolymerization initiator and its decomposition product in the adhesive composition may hinder the formation of an adhesive layer showing good durability. In the meantime, the content of the adhesive composition is 1.0 part by mass or less, preferably 0.1 part by mass or less, preferably 0.01 part by mass or less, more preferably 100 parts by mass or less. It is 0.001 parts by mass or less, and particularly preferably 0 parts by mass.

[2] Adhesive layer and optical film with adhesive layer and composition and manufacturing method thereof

The present invention is an adhesive layer comprising the above-described adhesive composition. The adhesive layer, for example, is prepared by dissolving or dispersing the above-mentioned adhesive composition in a solvent to form a solvent-containing adhesive composition, and secondly, by using the solvent-containing adhesive composition in an optical film or The surface of the film can be formed by coating and drying.

Further, the present invention also includes an optical film, and an optical film to which an adhesive layer is applied to the adhesive layer laminated on at least one surface of the optical film.

Since the adhesive layer of the present invention and the optical film to which the adhesive layer is applied are formed of the above-described adhesive composition, they are also durable in severe durability conditions (for example, durability conditions of 100 ° C or more). Sex.

Fig. 1 is a schematic cross-sectional view showing an example of an optical film to which an adhesive layer of the present invention is applied. The optical film 1 to which the adhesive layer is applied as shown in Fig. 1 is an optical film 10 and an optical film in which an adhesive layer 20 is laminated on one surface of the optical film. The adhesive layer 20 is usually laminated directly on the surface of the optical film 10. Further, the adhesive layer 20 may be laminated on both surfaces of the optical film 10.

When the 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 adhesive layer 20, or the surface activation treatment is performed. (e.g., primer layer treatment, corona treatment, etc.) is preferred, especially for those who perform corona treatment.

The optical film 10 is a single-sided protective polarizing plate as shown in FIG. 2, and the adhesive layer 20 is usually on one side of the polarizing film, that is, on the opposite side of the polarizing plate 2 and the first resin film 3. Lamination (ideally direct stacking). The optical film 10 is a case where the polarizing plate is protected on both sides as shown in Fig. 3. The adhesive layer 20 may be in the outer layer of either of the first and second resin films 3 and 4, or may be in two. The outer layer of the square.

Other antistatic layers may be formed between the optical film 10 and the adhesive layer 20. As the antistatic layer, a lanthanoid material such as polysiloxane or a tin-doped indium oxide or tin-doped inorganic metal-based material such as ruthenium oxide, or an organic organic compound such as polythiophene, polystyrenesulfonic acid or polyaniline may be used. Polymer material.

The optical film 1 to which the adhesive layer is applied may have a laminated separation film (release film) on the outer surface of the adhesive layer 20. This separation film is usually removed by peeling off when the adhesive layer 20 is used (for example, when a transparent conductive electrode or a glass substrate is laminated). The separation membrane is formed, for example, by an adhesive layer 20 of a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarboxylate or polyarylate. On the surface, a release processor such as a helium treatment can also be implemented.

The optical film 1 to which the adhesive layer is applied is obtained by dissolving or dispersing the components constituting the above-mentioned adhesive composition in a solvent to form a solvent-containing adhesive composition, and secondly, the solvent-containing adhesive composition is The surface of the optical film 10 is coated and dried, and is obtained by forming the adhesive layer 20. Further, the optical film 1 to which the adhesive layer is applied is formed in the release treatment surface of the separation film in the same manner as described above to form the adhesive layer 20, and the adhesive layer 20 is layered (transferred) on the surface layer of the optical film 10. Can be obtained.

The thickness of the adhesive layer is usually 2 to 40 μm, and is preferably 5 to 30 μm from the viewpoint of the durability of the optical film to which the adhesive layer is applied or the workability of the optical film to which the adhesive layer is applied. The best is 10 to 25 μm. When the thickness of the pressure-sensitive adhesive layer is equal to or less than the above upper limit value, workability is improved, and when it is at least the above lower limit value, durability is improved.

The adhesive layer is preferably in a temperature range of 23 to 120 ° C to exhibit a storage modulus of 0.001 to 10 MPa. Thereby, the durability of the optical film to which the adhesive layer is applied can be more effectively improved. "The storage elastic modulus of 0.001 to 10 MPa in the 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. The storage modulus is generally decreased as the temperature rises. As long as the storage modulus is within any of the above ranges at 23 ° C and 120 ° C, the storage elasticity within the above range can be set. rate. The storage elastic modulus of the adhesive layer can be measured by 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 indicator of the crosslink density. The adhesive layer of the present invention exhibits a predetermined gel fraction because of a certain crosslink density. That is, the gel fraction of the adhesive layer of the present invention is, for example, 70 to 90% by mass, desirably 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 for the antifoaming property or workability of the adhesive layer, and when the gel fraction is at most the upper limit value, it is advantageous for peeling resistance. Further, the gel fraction can be measured by the method described in the item of the examples.

[2-1] Optical film

The optical film 10 constituting the optical film 1 to which the adhesive layer is applied can be incorporated in an image display device such as a liquid crystal display device to obtain various optical films (films having optical characteristics).

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 enhancement film, an antiglare film, an antireflection film, a diffusion film, or a light concentrating film), or may be a plurality of layers. Construction (for example, polarizing plate, phase difference plate, etc.). The optical film 10 is preferably a polarizing plate, a polarizing plate, a phase difference plate or a retardation film, and particularly preferably a polarizing plate or a polarizing plate. In the present specification, the optical film refers to a functional film (for example, a functional film for improving the visibility of an image) for displaying an image (display screen or the like). In the present specification, the polarizing plate means that a resin film or a resin layer is laminated on at least one surface of the polarizing plate, and the phase difference plate means that a resin film or a resin layer is laminated on at least one surface of the retardation film.

[2-2] Polarizer

2 and 3 are schematic cross-sectional views showing an example of a layer structure of a 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) on one surface of the polarizing plate 2, and the polarizing plate 10b shown in Fig. 3 is used. The polarizing plate is further laminated (or laminated) on both surfaces of the polarizer 2 to protect the polarizing plate on both sides of the second resin film 4. The first and second resin films 3 and 4 may be bonded to the polarizer 2 via an adhesive layer or an adhesive layer which is not shown in the drawing. Further, the polarizing plates 10a and 10b may contain other films or layers than the first and second resin films 3 and 4.

The polarizer 2 absorbs linearly polarized light, which is a linearly polarized light having a vibrating surface parallel to the absorption axis, and has a linear polarizing property that transmits a vibrating surface having a vertical absorption axis (parallel to the transmission axis), and can be used, for example, in The polyvinyl alcohol-based resin film absorbs the film of the dichroic dye. Examples of the dichroic dye include iodine or a dichroic organic dye.

The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, for example, a polyvinyl acetate of a single polymer of vinyl acetate, a vinyl acetate, and a monomer which may be copolymerized (for example, an unsaturated carboxylic acid, an olefin, or a vinyl group) may be mentioned. A copolymer of an ether, an unsaturated sulfonic acid, an ammonium group-containing (meth) acrylamide, or the like, and a vinyl acetate.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may also be modified, for example, polyethylene formaldehyde modified with an aldehyde or polyethylene acetal. The average degree of polymerization of the polyvinyl alcohol-based resin is usually from 1,000 to 10,000, preferably from 1,500 to 5,000. Further, the average degree of polymerization of the polyvinyl alcohol-based resin can be determined in accordance with JIS K 6726.

Usually, a film made of a polyvinyl alcohol-based resin is used as a raw material film of the polarizer 2 . A polyvinyl alcohol-based resin can be produced by a known method. The thickness of the raw material film is usually from 1 to 150 μm, and is preferably 10 μm or more in consideration of easiness of elongation and the like.

The polarizer 2 may be, for example, a step of uniaxially stretching the raw material film, a step of absorbing the dichroic dye by the film dyed with the dichroic dye, a step of treating the film with an aqueous boric acid solution, and a step of washing the film with water. And finally dried and manufactured. The thickness of the polarizing plate 2 is usually 1 to 30 μm, and is preferably 20 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less from the viewpoint of thin film formation of the optical film 1 to which the adhesive layer is applied.

In the polarizing plate 2 in which a dichroic dye is adsorbed to a polyvinyl alcohol resin film, a separate film of a polyvinyl alcohol resin film is used as a raw material film, except that the film is subjected to uniaxial stretching treatment and two colors. In addition to the method (1), the coating liquid containing a polyvinyl alcohol-based resin (aqueous solution or the like) may be applied to the base film to obtain a dried polyvinyl alcohol system. After the base film of the resin layer, each base film is uniaxially stretched, and the stretched polyvinyl alcohol-based resin layer is subjected to a dyeing treatment of a dichroic dye. As the base film, a film made of a thermoplastic resin similar to the thermoplastic resin obtained by constituting the first and second resin films 3 and 4 to be described later can be used, and it is preferable to use polyethylene terephthalate. A polyester resin such as an alcohol ester, a polycarboxylate resin, a cellulose resin such as cellulose triacetate, a cyclic polyolefin resin such as a norbornene resin, or a polystyrene resin. The film. In the case of the above method (2), the polarizer 2 of the film can be easily produced, and for example, the polarizer 2 having a thickness of 7 μm or less can be easily produced.

The first and second resin films 3 and 4 are independent of each other and have translucency, and are preferably optically transparent thermoplastic resins. For example, a chain-like polyolefin resin (for example, a polyethylene resin or a poly-polymer) may be used. a polyolefin resin such as a propylene resin or a cyclic polyolefin resin (for example, a norbornene resin); a cellulose resin (for example, a cellulose ester resin); and a polyester resin (for example, a poly pair) Ethylene phthalate, polyethylene naphthalate, polybutylene terephthalate, etc.; polycarboxylate resin (for example, from 2,2-bis(4-hydroxyphenyl) a polycarboxylate derived from a bisphenol such as propane; (meth)acrylic resin; a polystyrene resin; a polyetheretherketone resin; a polyfluorene resin; or a mixture thereof A film made of a polymer or the like. In addition, each of the first and second resin films 3 and 4 is made of a cyclic polyolefin resin, a polycarboxylate resin, a cellulose resin, a polyester resin, a (meth)acrylic resin, or the like. The film to be formed is preferably a film composed of a cellulose resin or a cyclic polyolefin resin.

Examples of the chain-like polyolefin resin include a single polymer of a chain olefin such as a polyethylene resin or a polypropylene resin, and a copolymer of two or more kinds of chain olefins.

The cyclic polyolefin-based resin is a general term for a resin containing a cyclic olefin represented by norbornene or tetracyclododecene (alias: dimethanol octahydronaphthalene) or a derivative thereof as a polymerized unit. Examples of the cyclic polyolefin-based resin include a ring-opened (co)polymer of a cyclic olefin and a hydrogenated product thereof, a polymer to which a cyclic olefin is added, a cyclic olefin, and a chain olefin such as ethylene or propylene. It is also a copolymer of a vinyl aromatic compound, a (co)polymer modified with an unsaturated carboxylic acid or a derivative thereof, and the like. Among them, a norbornene-based resin of a norbornene-based monomer such as a norbornene or a polycyclic norbornene-based monomer which is a cyclic olefin is preferably used.

The cellulose resin is preferably a cellulose ester resin, that is, a part or a complete ester of cellulose, and examples thereof include cellulose acetate, propionate, and tyrosine. Mixed esters and the like. Among them, cellulose triacetate, cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate and the like are preferred.

The polyester resin is ester-bonded, and is a resin other than the cellulose ester-based resin, and is generally a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. Propylene phthalate, propylene naphthalate, dimethyl dimethyl terephthalate, cyclohexane dimethyl phthalate, and the like.

The polycarboxylate resin is a polyester formed of a carboxylic acid and ethylene glycol or bisphenol. Among them, from the viewpoint of heat resistance, weather resistance, and acid resistance, an aromatic polycarboxylate having a diphenyl alkane in a molecular chain is preferred. As the polycarboxylic acid ester, for example, 2,2-bis(4-hydroxyphenyl)propane (alias bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1 may be mentioned. Derived from bisphenols such as bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane and 1,1-bis(4-hydroxyphenyl)ethane Polycarboxylate and the like.

The (meth)acrylic resin obtained by constituting the first and second resin films 3 and 4 may be a polymer obtained from a structural unit derived from methacrylate (for example, containing 50% by mass or more). It is preferred to be a copolymerized copolymer with other copolymerizations.

The (meth)acrylic resin may contain two or more kinds of structural units derived from a methyl adienoate. Examples of the methacrylate include a C ₁ to C ₄ alkyl methacrylate such as methyl methacrylate, ethyl methacrylate or butyl methacrylate.

As a copolymerization component obtained by copolymerization with a methacrylate, an acrylate is mentioned. The acrylate is desirably a C ₁ to C ₈ alkyl acrylate such as methyl acrylate, ethyl acrylate, butyl acrylate or 2-ethylhexyl acrylate. Specific examples of the other copolymerization component include unsaturated acids such as (meth)acrylic acid; aromatic vinyl compounds such as styrene, halogenated styrene, α-methylstyrene, and vinyltoluene; a vinyl cyanide compound such as (meth)acrylonitrile; an unsaturated acid anhydride such as maleic anhydride or citraconic anhydride; an unsaturated quinone imine such as phenyl maleimide or cyclohexylmaleimine; There is one polymerizable carbon atom in the molecule - a double bond of a carbon atom, and a compound other than an acrylate. A compound having two or more polymerizable carbon atom-carbon atom double bonds in the molecule may be used as a copolymerization component. The copolymerization component may be used singly or in combination of two or more.

The (meth)acrylic resin may have a ring structure in the polymer main chain from the viewpoint of obtaining durability of the lift film. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic quinone imine structure or a lactone ring structure. Specific examples of the cyclic acid anhydride structure include a glutaric anhydride structure and a succinic anhydride structure. Specific examples of the cyclic quinone imine structure include a pentaneimine structure and an amber quinone structure. Specific examples of the lactone ring structure include a butyrolactone ring structure and a valerolactone ring structure.

The (meth)acrylic resin may contain acrylic rubber particles from the viewpoints of film forming properties of the film, impact resistance of the film, and the like. The acrylic rubber particles are particles in which an elastomeric polymer having an acrylate as a main component is an essential component, and examples thereof include a single layer structure in which only the elastic polymer is used, or an elastic polymer is formed as 1 The multilayer structure of the layer. Examples of the elastic polymer include a crosslinked elastic copolymer in which an alkyl acrylate is a main component, and other vinyl monomers and a crosslinkable monomer which may be copolymerized are copolymerized. Examples of the alkyl acrylate which is a main component of the elastic polymer include C ₁ to C ₈ alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. . The number of carbon atoms of the alkyl group is preferably 4 or more.

As another vinyl monomer which may be copolymerized with an alkyl acrylate, a compound having one polymerizable carbon atom-carbon atom double bond in the molecule may be mentioned, and more specifically, for example, methacrylic acid An ester methacrylate, an aromatic vinyl compound such as styrene, a vinyl cyanide compound such as (meth)acrylonitrile, or the like. Examples of the crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon atoms and a carbon atom double bond in the molecule, and more specifically, ethylene glycol di(meth)acrylic acid is exemplified. Polyol (meth) acrylate such as ester or butanediol di(meth) acrylate, alkenyl (meth) acrylate such as acryl (meth) acrylate, or divinyl benzene.

The content of the acrylic rubber particles is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more, based on 100 parts by mass of the (meth)acrylic resin. When the content of the acrylic rubber particles is too large, the surface hardness of the film is lowered, and in the case where the surface treatment is performed in the film, the solvent resistance may be lowered for the organic solvent in the surface treatment agent. Therefore, the content of the acrylic rubber particles is usually 80 parts by mass or less, and preferably 60 parts by mass or less, based on 100 parts by mass of the (meth)acrylic resin.

The first and second resin films 3 and 4 may contain additives which are generally used in the technical field of the present invention. Examples of the additives include ultraviolet absorbers, infrared absorbers, organic dyes, pigments, inorganic dyes, antioxidants, antistatic agents, surfactants, slip agents, dispersants, and thermal stabilizers. Examples of the ultraviolet absorber include a salicylate compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyano (meth) acrylate compound, a nickel salt, and the like.

Each of the first and second resin films 3 and 4 may be a film that does not extend, or a uniaxial or biaxially stretched film. The first resin film 3 and/or the second resin film 4 may be a protective film that functions to protect the polarizing film 2, or may be a protective film that also has an optical function as a retardation film to be described later. Further, 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 may have a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, and the like on the outer surface (the surface opposite to the polarizer 2). A surface treatment layer (coating layer) of an antistatic layer, an antifouling layer, a conductive layer, or the like. 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, preferably 5 to 60 μm, and more preferably 50 μm or less (for example, 1 to 40 μm). Specifically, it is 30 μm or less (for example, 5 to 25 μm).

In particular, it is suitable for a small-sized polarizing plate of a smart phone or a lithographic type end, and since it is required to be thinned, many of the first resin film 3 and/or the second resin film 4 have a thickness of 30 μm or less. However, such a polarizing plate suppresses the weakening of the contraction force of the polarizer 2, and the durability tends to be insufficient. Even in the case where such a polarizing plate is used as the optical film 10, the optical film 1 to which the adhesive layer of the present invention is applied has good durability.

The first and second resin films 3 and 4 can be bonded to the polarizer 2 via an adhesive layer or an adhesive layer. As the adhesive for forming the adhesive layer, a water-based adhesive or an active energy ray-curable adhesive can be used.

Examples of the water-based adhesive include a conventional water-based adhesive (for example, an adhesive made of a polyvinyl alcohol-based resin aqueous solution, an aqueous two-liquid amine ester-based latex adhesive, an aldehyde compound, an epoxy compound, or a melamine system). a compound, a methylol compound, an isocyanate compound, an amine compound, a crosslinking agent such as a polyvalent metal salt, or the like). Among them, a water-based adhesive made of a polyvinyl alcohol-based resin aqueous solution can be suitably used. In the case where the water-based adhesive is used, after the polarizer 2 is bonded to the first and second resin films 3 and 4, it is preferred to carry out the drying step in order to remove the water contained in the aqueous adhesive. After the drying step, a health step of, for example, curing at a temperature of about 20 to 45 ° C may also be provided.

The active energy ray-curable adhesive agent is an adhesive which is cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam, and examples thereof include a curable composition containing a polymerizable compound and a photopolymerization initiator, and a light-containing composition. The curable composition of the reactive resin, the curable composition containing the binder resin and the photoreactive crosslinking agent, and the like are preferably an ultraviolet curable adhesive.

In the case of using an active energy ray-curable adhesive, after the polarizer 2 is bonded to the first and second resin films 3 and 4, the drying step is necessary, and then the active energy ray is irradiated to perform the hardening active energy ray. A hardening step of a hardenable adhesive. Although the light source of the active energy ray is not particularly limited, it is preferably an ultraviolet ray having a light-emitting distribution at a wavelength of 400 nm or less.

As a method of bonding the polarizer 2 to the first and second resin films 3 and 4, saponification treatment, corona treatment, and plasma are performed on at least one of the bonding surfaces (plasma is also called plasma). A method of surface activation treatment such as plasma treatment. In the case where the resin film is bonded to both surfaces of the polarizer 2, the adhesive for bonding the resin films may be the same kind of adhesive or a different type of adhesive.

The polarizing plates 10a, 10b may further contain other films or layers. In this specific example, in addition to the retardation film to be described later, an adhesive layer, a coating layer, and a protective layer other than the brightness film, the antiglare film, the antireflection film, the diffusion film, the light concentrating film, and the adhesive layer 20 are provided. Membrane and the like. The protective film is a film which is used for the purpose of protecting the surface of the optical film 10 such as a polarizing plate from scratches or dirt. For example, the optical film 1 to which the adhesive layer is applied is usually laminated on a metal layer or a substrate. After that, it will be stripped and removed.

The protective film is usually composed of a base film and an adhesive layer laminated thereon. As the base film, a thermoplastic resin such as a polyolefin resin such as a polyethylene resin or a polypropylene resin; a polyester such as polyethylene terephthalate or polyethylene naphthalate may be used. A resin; a polycarboxylate resin; a (meth)acrylic resin or the like.

[2-3] phase difference plate

The retardation film contained in the retardation film is an optical film exhibiting optical anisotropy as described above, and can be used as the first and second resin films 3 and 4, except for the thermoplasticity exemplified above. In addition to the resin, for example, a polyvinyl alcohol resin, a polyarylate resin, a polyamidene resin, a polyether oxime resin, a polyvinylidene fluoride/polymethyl methacrylate resin can be used. A resin film obtained by extending a resin film such as a liquid crystal polyester resin, an ethylene-vinyl acetate copolymer saponified product, or a polychlorinated vinyl resin by a stretching film of about 1.01 to 6 times. In particular, a stretched film in which a polycarboxylate resin film, a cyclic olefin resin film, a (meth)acrylic resin film, or a cellulose resin film is uniaxially stretched or biaxially stretched is preferred. Further, in the present specification, the retardation film is also contained in the retardation film. However, a zero-latency film can be used as a protective film. Further, a film called a uniaxial retardation film, a wide viewing angle retardation film, or a low photoelasticity retardation film may be used as the retardation film.

The zero retardation film means that the in-plane phase difference value R _e and the thickness direction phase difference value R _th are both films of -15 to 15 nm. This retardation film is suitable for use in an IPS mode liquid crystal display device. The in-plane phase difference value R _e and the thickness direction phase difference value R _th are desirably -10 to 10 nm, and more preferably -5 to 5 nm. The so-called in-plane phase difference value R _e and the thickness direction phase difference value R _th are values at a wavelength of 590 nm.

The in-plane phase difference value R _e and the thickness direction phase difference value R _th are respectively of the following formula: R _e =(n _x -n _y )×d

R _th =[(n _x +n _y )/2-n _z ]×d is defined. In the formula, n _x is the refractive index in the x-axis direction (x-axis direction) in the film plane, and n _y is the refractive index in the direction of the phase axis in the film plane (in the in-plane perpendicular to the y-axis direction of the x-axis). n _z is a refractive index in the film thickness direction (z-axis direction perpendicular to the film surface), and d is the thickness of the film.

In the zero-latency film, for example, a polyolefin resin such as a cellulose resin, a chain polyolefin resin, or a cyclic polyolefin resin, or a polyethylene terephthalate resin or A resin film made of a (meth)acrylic resin. In particular, it is preferable to use a cellulose resin, a polyolefin resin or a (meth)acrylic resin because it is easy to obtain the phase difference value.

In addition, a film exhibiting optical anisotropy by coating or aligning a liquid crystal compound or a film exhibiting optical anisotropy by application of an inorganic layered compound may be used as a retardation film. In such a retardation film, a temperature-compensated retardation film is used, and a rod-shaped liquid crystal sold under the trade name "NH film" by JX Nippon Mining & Energy Co., Ltd. is a film of oblique alignment. The disc-shaped liquid crystal which is sold under the trade name of "WV film" by Fujifilm Co., Ltd. is a film of oblique alignment, and a completely biaxial alignment type film sold by Sumitomo Chemical Co., Ltd. under the trade name of "VAC film". A biaxial alignment type film sold by Sumitomo Chemical Co., Ltd. under the trade name "new VAC film". Meanwhile, the resin film laminated on at least one surface of the retardation film may be, for example, the above-mentioned protective film.

[3] Optical laminate

The present invention comprises the optical film to which the pressure-sensitive adhesive layer is applied, and an optical layered body comprising a substrate laminated on the side of the adhesive layer to which the optical film of the adhesive layer is applied. In the optical laminate of the present invention, since the adhesive layer is formed of the above-described adhesive composition, it has excellent durability even under severe durability conditions (for example, durability conditions of 100 ° C or more).

The base material is a conventional substrate, and examples thereof include 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 layered body according to the present invention.

The optical layered body 5 shown in Fig. 4 is an electrode layer 30 laminated on a substrate 40, laminated on the optical film 1a to which the adhesive layer is applied (or a polarizing plate 1a to which an adhesive layer is applied) An optical laminate on the side of the adhesive layer. The optical film 1a to which the adhesive layer is applied is one in which the adhesive layer 20 is formed on the side of the polarizer 2 of the polarizing plate 10a.

In the optical layered body 6 shown in Fig. 5, the electrode layer 30 laminated on the substrate 40 is laminated on the optical film 1b to which the adhesive layer is applied (or the polarizing plate 1b to which the adhesive layer is applied). An optical laminate on the side of the layer. The optical film 1b to which the adhesive layer is applied is an optical film of the layer of the adhesive layer 20 on the side of the second resin film 4 of the polarizing plate 10b.

The optical laminates 5 and 6 are obtained by laminating the optical film (1a, 1b) to which the adhesive layer is applied via the adhesive layer 20 in the electrode layer 30 laminated on the substrate 40.

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

The electrode layer 30 may contain, for example, a metal element selected from the group consisting of aluminum, copper, silver, iron, tin, zinc, nickel, molybdenum, chromium, tungsten, lead, and an alloy containing two or more of these metals. The metal layer. Among them, from the viewpoint of conductivity, a metal layer containing a metal element selected from at least one of aluminum, copper, silver, and gold is preferred. From the viewpoint of conductivity and cost, a metal layer containing an aluminum element is preferable, and a metal layer containing an aluminum element as a main component (constituting 50% by mass or more of the total metal component of the metal layer) is preferable. .

Further, the metal layer may be a layer in which a metal wire of a thin wire is disposed on a substrate, a metal nanoparticle or a metal nanowire is added to the adhesive.

The electrode layer 30 may, for example, be composed of a mixture of tin oxide, indium oxide, zinc oxide, gallium oxide, aluminum oxide, or the like. From the viewpoint of conductivity and visible light transmittance, ITO is preferred.

The electrode layer 30 is preferably a metal layer formed by a transparent electrode and a sputtering method, an inkjet printing method or a gravure printing method, and a metal layer formed by a transparent electrode and a sputtering method is more preferable.

The thickness of the electrode layer 30 is not particularly limited, but is usually 3 μm or less, preferably 1 μm or less, 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.

The optical layered body 7 shown in Fig. 6 is an optical layered body in which the adhesive layer 20 of the optical film 1 to which the adhesive layer is applied is laminated on the substrate 40.

In the optical layered body 8 shown in Fig. 7, the surface of the electrode layer 30 laminated on the substrate 40 (the surface on the opposite side to the substrate 40) is laminated, and the resin layer 50 is laminated to provide the adhesion. An optical layered body on the side of the adhesive layer 20 of the optical film 1 of the agent layer. The resin forming the resin layer 50 may, for example, be a resin constituting the first or second resin film exemplified above.

In the optical layered body 9 shown in Fig. 8, a plurality of electrode layers 30 are laminated on the substrate 40 at intervals defined by the longitudinal and lateral directions, and between the plurality of electrode layers 30 (or a gap) and the surface of the electrode layer 30. The upper (surface on the opposite side to the substrate 40) is formed (or laminated) with the resin layer 50, and the rest is the same as the optical laminate 7. In the case of the form of the optical layered body 9 (the shape of the electrode layer 30 is a pattern), the electrode layer 30 may have, for example, a metal wiring layer of a touch input element of a touch input type liquid crystal display device.

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

[4] Liquid crystal display device

The adhesive layer of the present invention, the optical film to which the adhesive layer is applied, and the optical laminate can be used in a liquid crystal display device, and the liquid crystal display device has excellent durability.

The liquid crystal display device may also be a touch input type liquid crystal display device having a touch panel function. The touch input type liquid crystal display device has a touch input element including a liquid crystal unit, and a backlight. The composition of the touch panel may also be in a conventional manner (for example, an external type, an oncell type, an in-line type, etc.), and the touch panel may be operated in a conventional manner, for example, Resistive film method, electrostatic capacity method (surface type electrostatic capacitance method, projection type electrostatic capacitance method), etc. The optical film to which the adhesive layer according to the present invention is applied may be disposed on the viewing side of the control input element (liquid crystal cell), may be disposed on the backlight side, or may be disposed in both. The driving method of the liquid crystal cell may be any conventional method such as a TN method, a VA method, an IPS method, a multi-domain method, or an OCB method. Further, in the liquid crystal display device, the substrate 40 having the optical layered body may include a substrate (typically a glass substrate) in the liquid crystal cell.

 [Examples]  

Hereinafter, the present invention will be specifically described by showing examples and comparative examples, but the present invention is not limited to these examples. Hereinafter, the amount used, the amount of the content, and the % are indicated, and unless otherwise stated, the quality is based on the standard.

<Production Example 1: Production of (meth)acrylic resin (B-1) for adhesive layer>

In a reaction vessel equipped with a condenser, a nitrogen gas introduction tube, a thermometer, and a stirrer, a solution obtained by mixing the constituent monomers shown in Table 1 (the values in Table 1 are parts by mass) with 81.8 parts of ethyl acetate was obtained. put into a. After replacing the air in the reaction vessel with nitrogen, the internal temperature was set at 60 °C. Thereafter, a solution of 0.12 parts of azobisisobutyronitrile dissolved in 10 parts of ethyl acetate was added. After maintaining at the same temperature for 1 hour, the internal temperature was maintained at 54 to 56 ° C while ethyl acetate was added at a rate of 17.3 parts per hour, and the concentration of the polymer was attempted to be continuously added in a manner of almost 35%. Into the reaction vessel. The internal temperature was maintained at 54 to 56 ° C for 12 hours from the start of the addition of ethyl acetate, and the concentration of the polymer was adjusted to 20% by adding ethyl acetate to obtain a (meth)acrylic resin (B-1). Ethyl acetate solution. 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.

<Production Examples 2 and 3: Production of (meth)acrylic resins (B-2) and (B-3) for adhesive layers>

The same procedure as in Production Example 1 was carried out except that the composition of the monomer was changed to the composition shown in Table 1, and acetic acid of (meth)acrylic resin (B-2) and (B-3) was obtained. Ethyl ester solution (resin concentration: 20%). The weight average molecular weight Mw of the obtained (meth)acrylic resin (B-2) was 1.42 million, Mw/Mn was 5.2, and the weight average molecular weight Mw of the (meth)acrylic resin (B-3) was 1.36 million. Mw/Mn is 4.1.

In the above production example, the weight average molecular weight Mw and the number average molecular weight Mn are measured by a GPC apparatus using the following conditions, and the column of the GPC apparatus is four of Tosoh Co., Ltd. "TSO gel XL" and one "Shodex GPC KF-802" manufactured by Showa Denko Co., Ltd., and the total of five columns are arranged in series, and tetrahydrofuran is used as a dissolving solution. The sample concentration is 5 mg/mL. The amount of introduction was 100 μL, the temperature was 40 ° C, and the flow rate was 1 mL/min, which was measured by standard polystyrene conversion. The conditions at which the discharge curve of the GPC is obtained are also the same.

The glass transition temperature Tg is a differential scanning calorimeter (DSC) "EXSTAR DSC 6000" manufactured by SII Nanotechnology Co., Ltd., and the temperature range is -80 to 50 ° C and the temperature rising rate is 10 ° C / min in a nitrogen atmosphere. Determined under conditions.

The monomer composition in each of the production examples (the numerical values in Table 1 are parts by mass) are shown in Table 1.

The abbreviation in the column of "monomer composition" in Table 1 means the following monomers.

BA: n-butyl acrylate (glass transition temperature of homopolymer: -54 ° C).

MA: methacrylate (glass transition temperature of homopolymer: 10 ° C), HEA: 2-hydroxyethyl acrylate.

5HPA: 5-hydroxypentyl acrylate

AAEM: Ethyl ethoxyethyl methacrylate

BMAA: Butoxymethyl propylene amide

PEA2: phenoxy diethylene glycol acrylate

AA: Acrylic

<Examples 1 to 6 and Comparative Examples 1 to 6>

(1) Modulation of adhesive composition

In the ethyl acetate solution (resin concentration: 20%) of the (meth)acrylic resin obtained in the above production example, the amount (parts by mass) shown in Table 2 was contained in 100 parts of the solid content of the solution. Si-Si bonded decane compound (A), crosslinking agent (C), and Si-Si-free decane compound (D), in Examples 1, 3 and 5, Comparative Examples 1, 3 and 5, further The antistatic agent (E) was mixed, and secondly, the solid content concentration was such that 14% of ethyl acetate was added to obtain an adhesive composition. The compounding amount of each component shown in Table 2 is a mass part of the solid content contained herein when the product to be used contains a solvent or the like.

Each of the detailed compounding components shown by the abbreviation in Table 2 is as follows.

(Si-Si-bound decane compound (A))

A-1: A product obtained by Osaka Gas Chemical Co., Ltd., named "OGSOL SI-20-10].

The weight average molecular weight (Mw) was 1600 and the number average molecular weight (Mn) was 1,000 in terms of standard polystyrene by GPC. A methylphenyl polydecane compound having a terminal hydroxyl group.

(crosslinking agent (C))

C-1: Ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid content concentration: 75%), trade name "Coronate L" obtained by Tosoh Corporation.

(Si-Si-free decane compound (D))

D-1:1,6-bis(trimethoxydecyl)hexane.

(antistatic agent (E))

E-1: N-decylpyridinium bis(fluorothioindolyl) imine.

(2) Production of adhesive layer

The separation film formed of the polyethylene terephthalate film subjected to the release treatment by the adhesive composition prepared in the above (1) (trade name "PLR- obtained by Lintec Co., Ltd." On the release-treated surface of 382190", the thickness of the film after drying was attempted to be 20 μm, and the film was applied by an applicator, and dried at 100 ° C for 1 minute to prepare an adhesive layer (adhesive sheet).

(3) Fabrication of an optical film (P-1) having an adhesive layer

A polyvinyl alcohol film (Kuraray Vinylon VF-PE #6000, manufactured by Kuraray Co., Ltd.) having an average polymerization degree of about 2400, a saponification degree of 99.9 mol%, and a thickness of 60 μm, at 37 ° C After immersion in pure water, it was immersed in an aqueous solution containing iodine and potassium iodide (iodine/potassium iodide/water (mass ratio) = 0.04/1.5/100) at 30 °C. Thereafter, 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 in 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 in polyvinyl alcohol. The extension, mainly, was carried out in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times.

A transparent protective film (trade name "KC40A" manufactured by Konica Minolta Optoelectronics Co., Ltd.) made of a cellulose triacetate film having a thickness of 40 μm was placed on one side of the obtained polarizer. An adhesive is formed by bonding an aqueous solution of an alcohol resin. Next, a zero retardation film (trade name "ZEONOR" manufactured by ZEON Co., Ltd., Japan) made of a cyclic polyolefin resin having a thickness of 23 μm is formed on the surface of the polarizer opposite to the cellulose triacetate film. A polarizing plate can be produced by bonding together with an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin. Next, on the side opposite to the surface of the zero retardation film and the polarizer, the surface opposite to the separation film of the adhesive layer prepared in the above (2) is applied after the corona discharge treatment for improving the adhesion ( On the adhesive layer, after laminating by a laminator, the cells were cured at a temperature of 23 ° C and a relative humidity of 65% for 7 days to obtain an optical film (P-1) to which an adhesive layer was applied.

(4) Evaluation of durability of optical film with adhesive layer

The optical film (P-1) to which the adhesive layer is produced in the above (3) is applied, and the direction of the axis of extension of the polarizing plate is cut to a size of 300 mm × 220 mm as a long side, and the separation film is peeled off and exposed. The adhesive layer is applied to a glass substrate to which a glass substrate or ITO (tin is doped with indium oxide) is applied. The obtained glass substrate is a test piece to be attached (the glass substrate is an optical film to which an adhesive layer is applied), and is pressurized in a pressure cooker at a temperature of 50 ° C and a pressure of 5 kg/cm ² (490.3 kPa) for 20 minutes. . The glass substrate was made of an alkali-free glass manufactured by Corning Incorporated under the trade name "Eagle XG". In addition, as a glass substrate to which ITO is added, a 30 nm ITO layer formed by evaporation of ITO in an alkali-free glass (trade name "Eagle XG") manufactured by Corning Incorporated can be used.

With respect to the obtained optical laminate, the following durability test was carried out.

[durability test]

‧ Heat resistance test (glass substrate) maintained at 500 ° C for 500 hours under dry conditions

‧ Heat resistance test for 500 hours under dry conditions at 105 ° C (with ITO glass substrate)

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

5: The appearance change of floating, peeling, foaming, etc. is not seen at all, 4: Appearance change such as floating, peeling, foaming, etc. is hardly observed 3: Appearance of floating, peeling, foaming, etc. is slightly seen Change, 2: Appearance changes such as floating, peeling, foaming, etc., 1: Significant changes in appearance such as floating, peeling, foaming, etc.

(6) Evaluation of antistatic property of optical film with adhesive layer

After the separation film of the obtained adhesive layer polarizing film was peeled off, the surface resistance value of the adhesive was measured by a surface specific resistance measuring device (Hiresta UP MCP-HT450 (trade name) manufactured by Mitsubishi Chemical Corporation). 〕 to determine. It was carried out under the measurement conditions of an applied voltage of 250 V and a demand time of 10 seconds. When the surface resistance value is 1.0 × 10 ¹² Ω/□ or less, good antistatic properties can be obtained.

[Gel fraction of adhesive sheet]

A method of evaluating the gel fraction of the adhesive sheet of the present invention is shown. The larger the gel fraction, the more the crosslinking reaction can be carried out in the adhesive, and it can be the target of the crosslinking 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 was bonded to a metal mesh (having a weight of Wm) of about 10 cm × about 10 cm of SUS 304.

(b) The mass of the composition obtained in the above (I) of the scale, the quality is regarded as Ws, and then the adhesive sheet is stacked four times in a wrapping manner to be scaled by the stapler, and the mass is regarded as Wb.

(c) The above-mentioned (II) stapled web was placed in a glass container, and after immersing in 60 mL of ethyl acetate, the glass container was stored at room temperature for 3 days.

(d) The net was taken out from the glass container, and dried at 120 ° C for 24 hours, and then the mass was weighed. The mass was used as Wa, and the gel fraction was calculated according to the following formula.

Gel fraction (% by mass) = [{Wa-(Wb-Ws)-Wm}/(Ws-Wm)] × 100

Claims (21)

 An adhesive composition comprising a Si-Si-bonded decane compound (A).    The adhesive composition according to claim 1, wherein the decane compound (A) is a decane compound having a weight average molecular weight of 300 or more.    The adhesive composition according to claim 1 or 2, wherein the decane compound (A) is a polydecane compound having a crosslinked structure in a molecule.    The adhesive composition according to any one of claims 1 to 3, wherein the decane compound (A) is a compound having a hydroxyl group.    The adhesive composition according to any one of claims 1 to 4, which further comprises a (meth)acrylic resin (B), a crosslinking agent (C), and a Si-Si-free combination. Decane compound (D).    The adhesive composition according to any one of the first to fifth aspects of the invention, wherein the weight average molecular weight of the (meth)acrylic resin (B) is 1,000,000 or more in terms of polystyrene.   The adhesive composition according to any one of claims 1 to 6, wherein the (meth)acrylic resin (B) contains at least one selected from the group consisting of the following formula (b1) Structural unit from a hydroxyl group-containing (meth) acrylate (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 may be used. a structural unit derived from a hydroxyl group-containing (meth) acrylate (b2) 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, and X ² represents a methylene group which may have a substituent, and the above substituents may be the same or may be different and derived from the presence of B. A structural unit of (meth) acrylate (b3).  The adhesive composition according to claim 7, wherein the (meth)acrylic resin (B) contains a structural unit derived from a hydroxyl group-containing (meth) acrylate (b1), and a source thereof. The structural unit derived from the hydroxyl group-containing (meth) acrylate (b2) or the structural unit derived from the ethyl methacrylate-containing (meth) acrylate (b3).    The adhesive composition according to claim 8, wherein the structural unit derived from the hydroxyl group-containing (meth) acrylate (b1) is derived from the hydroxyl group-containing (meth) acrylate (b2) The mass ratio (b1) / (b2 or b3) of the structural unit or the structural unit derived from the (meth) acrylate (b3) containing an ethyl fluorenyl group is 14 to 1.    The adhesive composition according to any one of claims 5 to 9, wherein the (meth)acrylic resin (B) contains an alkane derived from a homopolymer having a glass transition temperature of less than 0 ° C. The structural unit of the acrylate (b4) and the structural unit derived from the alkyl acrylate (b5) having a glass transition temperature of 0 ° C or higher derived from the homopolymer.    The adhesive composition according to claim 10, wherein the glass transition temperature derived from the homopolymer is a structural unit of an alkyl acrylate (b4) which is less than 0 ° C, and a homopolymer derived from The mass ratio (b4)/(b5) of the structural unit of the alkyl acrylate (b5) having a glass transition temperature of 0 ° C or more is 0.1 to 10.    The adhesive composition according to any one of claims 5 to 11, wherein the (meth)acrylic resin (B) is derived from a substituent-containing (meth) acrylate. The ratio of the structural unit is 1.0 part by mass or less based on 100 parts by mass of all the structural units constituting the (meth)acrylic resin (B).    The adhesive composition according to any one of claims 5 to 12, wherein the crosslinking agent (C) is an isocyanate compound.    The adhesive composition according to any one of claims 5 to 13, wherein the ratio of the crosslinking agent (C) is 0.01% based on 100 parts by mass of the (meth)acrylic resin (B). Up to 10 parts by mass.   The adhesive composition according to any one of claims 5 to 14, wherein the decane compound (D) is a decane compound represented by the following formula (d1) In the formula, B represents an alkylene group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH ₂ - constituting the above alkyl group and the above alicyclic hydrocarbon group may also be used. Substituted as -O- or -CO-, R ⁷ represents an alkyl group having 1 to 5 carbon atoms, and R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently, and represent 1 to 5 carbon atoms. The alkyl group is an alkoxy group having 1 to 5 carbon atoms.  The adhesive composition according to any one of claims 5 to 15, wherein the ratio of the decane compound (D) is 0.01 to 100 parts by mass based on the (meth)acrylic resin (B). 10 parts by mass.    The adhesive composition according to any one of claims 1 to 16, which is substantially free of a photopolymerization initiator and a decomposition product thereof.    An adhesive layer comprising the adhesive composition according to any one of claims 1 to 17.    The adhesive layer as described in claim 18, wherein the adhesive layer has a gel fraction of 70 to 90%.    An optical film provided with an adhesive layer comprising an optical film and an adhesive layer laminated on at least one side of the optical film, the adhesive layer being the adhesive described in claim 18 or 19. Floor.    An optical laminate comprising an optical film to which an adhesive layer according to claim 20 is applied, and a substrate laminated on the side of the adhesive layer of the optical film to which the adhesive layer is applied.