TW201903101A - Adhesive composition - Google Patents

Abstract

The present invention provides an adhesive composition containing a siloxane compound (A) which is a hydrolytic condensate (a) of a hydrolyzable condensable silane compound represented by the following formula (a1). (In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH2- in the alkanediyl group and the alicyclic hydrocarbon group may be replaced by -O- or -CO-, R1 and R2 each independently represents an alkyl group having 1 to 5 carbon atoms, R3, R4, R5 and R6 each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms).

Description

   Adhesive composition   

The present invention claims priority from Japanese Patent Application No. 2017-103018 (application date: May 24, 2017) in accordance with the Paris Convention, and is hereby incorporated by reference in its entirety for reference.

The present invention relates to an adhesive composition useful as an optical member used in a liquid crystal display device, etc., an adhesive layer composed of the adhesive composition, an optical film including an adhesive layer with the adhesive layer, and the adhesive film. Optical laminated body of optical film of adhesive layer, and siloxane compound for adhesive.

An optical film typified by a polarizing plate formed by laminating a transparent resin film on one side or two area layers of a polarizer is widely used as an optical member constituting an image display device such as a liquid crystal display device. Optical films such as polarizing plates are mostly used by being bonded to other members (such as liquid crystal cells in a liquid crystal display device) through an adhesive layer (see Patent Document 1). Therefore, as an optical film, there is known an optical film with an adhesive layer provided with an adhesive layer on one side thereof in advance.

    [Prior technical literature]         [Patent Literature]    

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

In recent years, liquid crystal display devices have been developed to be used for mobile devices such as smart phones or tablet terminals, or for vehicle loading devices such as car navigation systems. In such applications, there is a possibility of being exposed to a severe environment as compared with conventional indoor TV applications. Therefore, the problem of improving the durability of the device arises.

The optical film with an adhesive layer which comprises a liquid crystal display device etc. also requires durability similarly. That is, the adhesive layer assembled on a liquid crystal display device or the like will be placed in a high-temperature or high-temperature and high-humidity environment, or a high-temperature and low-temperature environment. Therefore, for optical films with an adhesive layer, it is expected that Under these circumstances, it is also possible to suppress the problems such as floating or peeling of the interface between the adhesive layer and the optical member to which it is attached, foaming of the adhesive layer, and the like, and it is also expected that the optical characteristics will not deteriorate. In particular, an optical film with an adhesive layer is used (laminated or laminated) for a touch panel such as ITO (doped tin indium oxide) transparent electrodes, etc. It is difficult to exhibit high durability under the severe and durable conditions mentioned above. In this case, high durability is also required in this case.

Therefore, the object of the present invention is to provide an adhesive composition, an adhesive layer composed of the adhesive composition, an optical film with an adhesive layer containing the adhesive layer, and an optical film with the adhesive layer An optical laminate and a siloxane compound for an adhesive. The adhesive composition, even when used in a transparent electrode layer such as ITO, can form an adhesive layer that exhibits good durability under severe durability conditions.

The present inventors have diligently studied in order to solve the above problems, and as a result, have completed the present invention. That is, the present invention includes the following.

[1] An adhesive composition containing a siloxane compound (A), and the siloxane compound (A) is a hydrolysis-condensation condensate (a) of a hydrolysis-condensable silane compound represented by the following formula (a1), (In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, which constitutes -CH ₂ -of the aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group. Substituted by -O- or -CO-, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a carbon number 1 to 5 Alkyl or alkoxy having 1 to 5 carbons).

[2] The adhesive composition according to [1], wherein the content of the alkoxy group contained in the siloxane compound (A) is relative to the content of the alkoxy group contained in the hydrolyzable and condensable silane compound (a1). The total amount is 100 mol%, ranging from 60 to 95 mol%.

[3] The adhesive composition according to [1] or [2], wherein the weight average molecular weight of the siloxane compound (A) is 600 to 4000 in terms of styrene.

[4] The adhesive composition according to any one of [1] to [3], further comprising a (meth) acrylic resin (B) and a crosslinking agent (C).

[5] The adhesive composition according to [4], wherein the proportion of the siloxane compound (A) is 0.01 to 10 parts by mass based on 100 parts by mass of the (meth) acrylic resin (B).

[6] The adhesive composition according to [4] or [5], wherein the (meth) acrylic resin (B) contains an alkyl acrylate derived from a monomer and having a glass transition temperature of less than 0 ° C. The constituent unit of (b1) and the constituent unit of the alkyl acrylate (b2) having a glass transition temperature of 0 ° C or higher derived from a monomer.

[7] The adhesive composition according to any one of [4] to [6], wherein the (meth) acrylic resin (B) contains a carboxyl group-containing (meth) acrylate The proportion of the constituent units is 1.0 part by mass or less with respect to 100 parts by mass of the total constituent units constituting the (meth) acrylic resin (B).

[8] The adhesive composition according to any one of [4] to [7], wherein the weight average molecular weight of the (meth) acrylic resin (B) is 1 to 2.5 million in terms of polystyrene. .

[9] The adhesive composition according to any one of [4] to [8], wherein the crosslinking agent (C) is an isocyanate-based compound.

[10] The adhesive composition according to any one of [4] to [9], wherein the proportion of the cross-linking agent (C) is 100 parts by mass based on (meth) acrylic resin (B), It is 0.01 to 10 parts by mass.

[11] An adhesive layer comprising the adhesive composition according to any one of [1] to [10].

[12] An optical film with an adhesive layer is formed by laminating the adhesive according to [11] on at least one side of the optical film.

[13] The optical film with an adhesive layer as described in [12], wherein the adhesive layer on the surface of the optical film with an adhesive layer not bonded to the optical film is bonded to a glass substrate at a temperature of 23 Adhesion after storage for 24 hours at ℃ and relative humidity of 50%. The peeling speed is 300mm / min. 0.5 to 10N / 25mm.

[14] An optical laminated body, which is an optical film including the adhesive layer according to [12] or [13].

[15] A siloxane compound (A) for an adhesive, which is a hydrolysis-condensation condensate (a) of a hydrolysis-condensable silane compound represented by the following formula (a1), (In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH ₂ -which may constitute the aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group may be -O. -Or -CO- substituted, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms Or alkoxy having 1 to 5 carbons).

Even when the adhesive composition of the present invention is used in a transparent electrode layer such as ITO, it can form an adhesive layer that exhibits good durability under severe durability conditions.

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

2‧‧‧ polarizer

3‧‧‧first resin film

4‧‧‧Second resin film

5, 6, 7, 8, 9‧‧‧ optical laminated body

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 with an adhesive layer formed from 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 laminate including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

FIG. 5 is a schematic cross-sectional view showing another example of an optical laminate including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

FIG. 6 is a schematic cross-sectional view showing another example of an optical laminate including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

FIG. 7 is a schematic cross-sectional view showing still another example of an optical laminate including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

FIG. 8 is a schematic cross-sectional view showing still another example of an optical laminated body including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

[1] Adhesive composition

The adhesive composition of the present invention contains a siloxane compound (A).

[1-1] Siloxane compound (A)

The silicone compound (A) is a hydrolysis-condensation product (a) of a hydrolysis-condensable silane compound represented by the following formula (a1).

(In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, which constitutes -CH ₂ -of the aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group. -Or -CO- substituted.

R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms.

R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. )

In formula (a1), B represents an alkanediyl group having 1 to 20 carbon atoms such as methylene, ethylene, propyl, butyl, hexyl, heptyl, and octyl; cyclobutenyl (E.g. 1,2-cyclobutenyl), cyclopentenyl (e.g. 1,2-cyclopentenyl), cyclohexenyl (e.g. 1,2-cyclohexenyl), cyclooctenyl (e.g. 1,2-cyclooctenyl) and other bivalent alicyclic hydrocarbon groups having 3 to 20 carbons; or -CH _2- , which constitutes the alkanediyl groups and the aforementioned alicyclic hydrocarbon groups, and is -O- or -CO- Superseded by. Preferred B is an alkanediyl group having 1 to 10 carbon atoms.

R ³ , R ⁴ , R ^5, and R ⁶ each independently represent a carbon number of 1 to 5 such as methyl, ethyl, propyl, isopropyl, butyl, secondary butyl, tertiary butyl, and pentyl. An alkyl group; or an alkoxy group having 1 to 5 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, secondary butoxy, tertiary butoxy, and the like. R ³ , R ⁴ , R ⁵ and R ^{6 are} preferably each independently an alkoxy group having 1 to 5 carbon atoms.

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ¹ and R ² are the same as the alkyl group having 1 to 5 carbon atoms represented by R ³ , R ⁴ , R ^5, and R ⁶ .

Specific examples of the silane compound (a1) include bis (trimethoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, and 1,2-bis (triethoxysilyl) ethyl. Alkane, 1,3-bis (trimethoxysilyl) propane, 1,3-bis (triethoxysilyl) propane, 1,4-bis (trimethoxysilyl) butane, 1,4- Bis (triethoxysilyl) butane, 1,5-bis (trimethoxysilyl) pentane, 1,5-bis (triethoxysilyl) pentane, 1,6-bis (trimethyl) Oxysilyl) hexane, 1,6-bis (triethoxysilyl) hexane, 1,6-bis (tripropoxysilyl) hexane, 1,8-bis (trimethoxysilyl) Octane, 1,8-bis (triethoxysilyl) octane, 1,8-bis (tripropoxysilyl) octane, and other bis (triC _1-5 alkoxysilyl) C _1-10 alkane; bis (dimethoxysilyl) methane, 1,2-bis (dimethoxysilyl) ethane, 1,2-bis (diethoxysilyl) ethane, 1 1,4-bis (dimethoxysilyl) butane, 1,4-bis (diethoxysilyl) butane, 1,6-bis (dimethoxysilyl) hexane, 1,6 - bis (diethoxy silicon based) hexane, 1,8-bis (silicon based dimethoxyphenyl) octane, 1,8-bis (diethoxy silicon based) octane, bis (C _{1 -5} alkoxy C _1-5 alkylsilyl) C _1-10 alkane; 1,6- Bis (mono C _1-5 alkoxy-di C _1-5 alkyl) such as bis (methoxydimethylsilyl) hexane, 1,8-bis (methoxydimethylsilyl) octane Silyl) C _1-10 alkanes and the like. Among these, 1,2-bis (trimethoxysilyl) ethane, 1,3-bis (trimethoxysilyl) propane, and 1,4-bis (trimethoxysilyl) butyl are preferred. Bis (trimethylsilyl), 1,5-bis (trimethoxysilyl) pentane, 1,6-bis (trimethoxysilyl) hexane, 1,8-bis (trimethoxysilyl) octane, etc. C _1-3 alkoxysilyl) C _1-10 alkane, particularly preferably 1,6-bis (trimethoxysilyl) hexane and 1,8-bis (trimethoxysilyl) octane.

The hydrolyzed condensate (a) of the hydrolyzable and condensable silane compound represented by the formula (a1) (hereinafter, also referred to as the hydrolysable and condensable silane compound (a1)) means a hydrolyzable group in the hydrolyzable and condensable silane compound (a1). An alkoxy-based condensate obtained by hydrolysis and condensation, such as a dimer or an oligomer. The hydrolyzed condensate (a) may be a hydrolyzed condensate (also referred to as a partially hydrolyzed condensate) obtained by partially hydrolyzing and condensing one of the alkoxy groups of the hydrolyzable condensable silane compound (a1), or may be the alkoxy group. All of them are hydrolyzed and condensed condensates. In addition, the alkoxy group of the hydrolytically condensable silane compound (a1) is hydrolyzed to a hydroxyl group, and then the generated hydroxyl group is condensed, or a part of the hydroxyl group does not condense and remains in the hydrolyzed condensate (a).

The hydrolyzed condensate (a) preferably has a structure in which the constituent unit derived from the hydrolyzed and condensable silane compound (a1) is transmitted through Si- O-Si bonding structure. The hydrolysis-condensation product (a) may be linear or branched.

Since the adhesive composition of the present invention contains the siloxane compound (A), even when the adhesive layer composed of the adhesive composition is used (laminated or laminated) on the electrode layer, the durability of the adhesive layer can be improved. It can effectively suppress the peeling (or floating) and foaming of the interface even in a high temperature environment. Moreover, this adhesive composition also has good reworkability (peelability). Therefore, the adhesive composition of the present invention can achieve both good durability and reworkability.

In this specification, the term "durability" means that, for example, in a high-temperature environment, a high-temperature and high-humidity environment, and an environment in which high and low temperatures are repeated, it is possible to suppress the floating or peeling of the interface between the adhesive layer and the adjacent optical member. Characteristics (also known as peel resistance), and characteristics that suppress foaming of the adhesive layer (such as foam resistance). In addition, in the present specification, the term “agglomerative destructive property” refers to a property capable of suppressing the aggregate destruction (or cracking) of the adhesive layer.

The hydrolyzed condensate (a) is preferably a partially hydrolyzed condensate of a hydrolyzed condensable silane compound (a1). The content of the alkoxy group contained in the siloxane compound (A) is 100 mol% with respect to the total amount of alkoxy groups contained in the hydrolyzable and condensable silane compound (a1), preferably 60 mol% or more. It is preferably 65 mol% or more, more preferably 70 mol% or more, more preferably 95 mol% or less, more preferably 90 mol% or less, and still more preferably 88 mol% or less. The limit value and the upper limit value may be arbitrarily combined, and may be, for example, 60 to 95 mol%, preferably 65 to 90 mol%, and more preferably 70 to 88 mol%. If the content of the alkoxy group in the siloxane compound (A) is above the lower limit value, the durability of the adhesive layer can be further improved, and if it is below the above upper limit value, the adhesive layer can be further improved. Reworkability.

The content of the alkoxy group contained in the siloxane compound (A) can be adjusted by the amount of the hydrolyzed water. The 1 mol alkoxy group contained in the hydrolyzable condensable silane compound (a1) is hydrolyzed with 0.5 mol hydrolyzed water. With respect to 100 mol% of the total alkoxy groups contained in the hydrolyzable condensable silane compound (a1), if the content of the alkoxy group contained in the siloxane compound (A) is 60 mol%, the hydrolytic condensation property 40% of the alkoxy group of the silane compound (a1) is hydrolyzed, and the hydrolysis rate is 40%. When the content of the alkoxy group contained in the siloxane compound (A) is 95 mol%, 5% of the alkoxy group of the hydrolyzable condensation silane compound (a1) is hydrolyzed, and the hydrolysis rate is 5%.

The weight average molecular weight of the siloxane compound (A) by polystyrene conversion by gel permeation chromatography GPC is preferably 600 or more, more preferably 700 or more, still more preferably 800 or more, and more preferably 4,000 or less The lower limit value and the upper limit value may be arbitrarily combined, for example, 600 to 4000, preferably 700 to 3000, and more preferably 800 to 2000. When the weight average molecular weight is in the above range, the durability and reworkability of the adhesive layer can be further improved.

The siloxane compound (A) may be a hydrolyzed condensable silane compound (a1) alone or two or more kinds of hydrolyzed condensates (a) obtained by hydrolysis and condensation. The siloxane compound (A) may be a hydrolyzed condensable silane compound (a1) and a hydrolyzed condensable silane compound (also referred to as a hydrolyzed condensable silane compound (a2)) other than the hydrolyzed condensable silane compound (a1). Hydrolyzed condensate (a). When the hydrolyzable and condensable silane compound (a2) is used in combination, the hydrolyzable and condensable silane compound (a1) preferably contains 70 mol% or more, more preferably 80 mol% or more, and more preferably Above 90 mol%, particularly preferred is above 95 mol%.

In addition to the hydrolyzed condensate (a), the siloxane compound (A) may contain one or two or more non-condensed hydrolyzed condensable silane compounds (a1). Moreover, when a hydrolysis-condensable silane compound (a2) is used together, a siloxane compound (A) may contain a non-condensed hydrolysis-condensable silane compound (a2). As long as the alkoxy group of the non-condensed, hydrolyzed and condensable silane compound (a1) or (a2) is not condensed, it can be partially or completely hydrolyzed (converted to a hydroxyl group).

Examples of the hydrolysis-condensable silane compound (a2) other than the hydrolysis-condensable silane compound (a1) include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxy. Silane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, trimethylmethoxysilane, trimethylethyl Oxysilane, vinyltri-dimethoxysilane, vinyltri-diethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxy Silane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxy Silane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethyl Oxysilane, 3-propenyloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl ) -3-aminopropyltrimethoxysilane 3-amino propyl trimethoxy Silane, 3-amino-propyl triethoxysilane Silane, 3-mercaptopropyl methyl dimethoxy silane-methoxy and 3-mercaptopropyl silane-group and the like.

The proportion of the siloxane compound (A) is preferably 100% by mass or more with respect to the total amount of the adhesive composition, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, and particularly preferably It is 0.2 mass% or more, preferably 10 mass% or less, more preferably 5 mass% or less, still more preferably 3 mass% or less, particularly preferably 1 mass% or less, and most preferably 0.5 mass% or less. Any combination of the lower limit and the upper limit may be, for example, 0.01 to 10% by mass, preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, still more preferably 0.1 to 1% by mass, Particularly preferred is 0.2 to 0.5% by mass. When the ratio of the siloxane compound (A) is within the above range, the durability and reworkability of the adhesive layer can be further improved.

When the adhesive composition contains a (meth) acrylic resin (B) described later, the content of the siloxane compound (A) is preferably 0.01 to 100 parts by mass of the (meth) acrylic resin (B). Part by mass or more, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more, particularly preferably 0.2 part by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass Mass parts or less, particularly preferably 1 mass parts or less, and preferably 0.5 mass parts or less, may be any combination of the lower limit and the upper limit, for example, 0.01 to 10 parts by mass, and more preferably 0.05 to 3 parts by mass, more preferably 0.1 to 1 part by mass, and particularly preferably 0.2 to 0.5 part by mass. When the ratio of the siloxane compound (A) is within the above range, the durability and reworkability of the adhesive layer can be further improved.

A conventional method can be used for the production method of the siloxane compound (A). For example, in the presence of a solvent, a catalyst (for example, an acid catalyst, a basic catalyst, etc.) is added as needed to hydrolyze the condensable silane. A method of mixing and stirring the compound (a1) and, if necessary, a hydrolyzable condensation silane compound (a2).

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

The (meth) acrylic resin (B) preferably contains 50 mass of the constituent unit derived from the (meth) acrylic monomer based on 100 mass% of the total constituent unit constituting the (meth) acrylic resin (B). % Or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more of a polymer or copolymer. In the present specification, "(meth) acrylic acid" means acrylic acid or methacrylic acid, and "(meth) acrylic acid ester" and "(meth) acrylfluorenyl group" also refer to acrylates, respectively. Or methacrylic acid, methacryl or methacryl.

The (meth) acrylic resin (B) may contain, for example, a constituent unit derived from a (meth) acrylic acid ester containing a polar functional group, a constituent unit derived from a (meth) acrylamide-based monomer, or a benzene derivative. A structural unit derived from a vinyl monomer, a structural unit derived from a vinyl monomer, a structural unit derived from a monomer having a plurality of (meth) acrylfluorene groups in the molecule, a structural unit derived from an alkyl acrylate, A constituent unit of an alkyl acrylate containing a substituent and the like. These constituent units can be used alone or in combination of two or more.

Examples of the (meth) acrylate containing a polar functional group include a (meth) acrylate containing a hydroxyl group, a (meth) acrylate containing a heterocyclic group such as an epoxy group, and a (meth) acrylate containing a substituted or unsubstituted amine group. (Meth) acrylates, carboxyl-containing (meth) acrylates, and the like.

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

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

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

In the formula (b1) and the formula (b2), X ¹ and X ² represent a methylene group which may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), and an alkyl group (such as methyl, ethyl, propyl, isopropyl, butyl, secondary butyl, and tertiary C _1-10 alkyl such as butyl, pentyl, and hexyl, preferably C _1-6 alkyl, more preferably C _1-3 alkyl), cycloalkyl (such as cyclopentyl, cyclohexyl, etc.), Aryl [e.g. phenyl, alkylphenyl (tolyl, xylyl, etc.)], aralkyl (e.g. benzyl, etc.), alkoxy (e.g. C _1-4 alkane such as methoxy, ethoxy, etc.) (Oxy), polyoxyalkylene (e.g. dioxyvinyl, etc.), cycloalkoxy (e.g. C _5-10 cycloalkoxy, etc.), aryloxy (e.g. phenoxy, etc.) , Aralkyloxy (e.g. benzyloxy, etc.), alkylthio (e.g. C _1-4 alkylthio, such as methylthio, ethylthio, etc.), cycloalkylthio (e.g. cyclohexylthio, etc.), Arylthio (for example, phenylthio, etc.), aralkylthio (for example, benzylthio, etc.), fluorenyl (for example, ethylfluorenyl, etc.), nitro, cyano, and the like. Among these, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, and the like are preferred, and an alkyl group (for example, methyl, ethyl, etc.) is particularly preferred.

Examples of the alkyl group represented by A ¹ and A ² include C _1-10 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, secondary butyl, tertiary butyl, pentyl, and hexyl. , Preferably methyl and the like.

In formula (b1), n represents an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2. In formula (b2), m represents an integer of 5 or more, and may be, for example, an integer of 5 to 20, preferably an integer of 5 to 15, more preferably an integer of 5 to 9, or even more preferably 5 to 7. Integer. M is preferably an odd number.

Specific examples of the hydroxyl-containing (meth) acrylate (b1) include 1-hydroxymethyl (meth) acrylate, 1-hydroxyethyl (meth) acrylate, and 1-hydroxyheptyl (meth) acrylate. Esters, 1-hydroxybutyl (meth) acrylate, 1-hydroxypentyl (meth) acrylate, etc. 1-hydroxy C _1-8 alkyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate (Meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, 2-hydroxyhexyl (meth) acrylate, etc. 2-hydroxy C _2-9 alkyl ester; 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 3-hydroxypentyl (meth) acrylate, 3 (meth) acrylate -Hydroxyhexyl ester, 3-hydroxyheptyl (meth) acrylate, etc. 3-hydroxy C _3-10 alkyl (meth) acrylate; 4-hydroxybutyl (meth) acrylate, 4- (meth) acrylate 4- 4-hydroxy C _4-11 alkane (meth) acrylate, such as hydroxypentyl ester, 4-hydroxyhexyl (meth) acrylate, 4-hydroxyheptyl (meth) acrylate, 4-hydroxyoctyl (meth) acrylate Ester; 2-chloro-2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, (methyl ) 2-hydroxy-3-phenoxypropyl acrylate and the like. Among these, from the viewpoint of durability, a hydroxyl group containing n such as 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate is preferred. (Meth) acrylate; 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 3-hydroxypentyl (meth) acrylate, etc. Based) acrylate. In particular, a hydroxyl-containing (meth) acrylate having n of 2 is preferable, and among these, 2-hydroxyethyl (meth) acrylate is preferable.

Specific examples of the hydroxyl-containing (meth) acrylate (b2) include, for example, 5-hydroxypentyl (meth) acrylate, 5-hydroxyhexyl (meth) acrylate, and 5-hydroxyheptyl (meth) acrylate. Ester, 5-hydroxyoctyl (meth) acrylate, 5-hydroxynonyl (meth) acrylate, etc. 5-hydroxy C _5-12 alkyl (meth) acrylate; 6-hydroxyhexyl (meth) acrylate (Meth) acrylic acid, such as 6-hydroxyheptyl (meth) acrylate, 6-hydroxyoctyl (meth) acrylate, 6-hydroxynonyl (meth) acrylate, 6-hydroxydecyl (meth) acrylate, etc. 6-hydroxy C _6-13 alkyl ester; 7-hydroxyheptyl (meth) acrylate, 7-hydroxyoctyl (meth) acrylate, 7-hydroxynonyl (meth) acrylate, 7 (meth) acrylate -Hydroxydecyl ester, 7-hydroxyundecyl (meth) acrylate, etc. 7-hydroxy C _7-14 alkyl (meth) acrylate; 8-hydroxyoctyl (meth) acrylate, 8 (meth) acrylic acid -Hydroxynonyl ester, 8-hydroxydecyl (meth) acrylate, 8-hydroxyundecyl (meth) acrylate, 8-hydroxydodecyl (meth) acrylate, and 8-hydroxy C ₈ (meth) acrylate _-15 alkyl ester; 9-hydroxynonyl (meth) acrylate, 9-hydroxydecyl (meth) acrylate, (meth) 9-hydroxyundecyl acrylate, 9-hydroxydodecyl (meth) acrylate, 9-hydroxytridecyl (meth) acrylate, and 9-hydroxy C _9-16 alkyl (meth) acrylate; ()) 10-hydroxydecyl acrylate, 10-hydroxyundecyl (meth) acrylate, 10-hydroxydodecyl (meth) acrylate, 10-hydroxytridecyl (meth) acrylate, (meth) acrylic acid 10-hydroxytetradecyl ester, etc. 10-hydroxy C _10-17 alkyl (meth) acrylate; 11-hydroxyundecyl (meth) acrylate, 11-hydroxydodecyl (meth) acrylate, (methyl ) 11-hydroxytridecyl acrylate, 11-hydroxytetradecyl (meth) acrylate, 11-hydroxypentadecyl (meth) acrylate, and 11-hydroxy C _11-18 alkyl (meth) acrylate; 12-hydroxydodecyl (meth) acrylate, 12-hydroxytridecylate (meth) acrylate, 12-hydroxytetradecyl (meth) acrylate, and 12-hydroxy C _12-19 alkyl (meth) acrylate ; 13-hydroxytridecyl (meth) acrylate, 13-hydroxytetradecyl (meth) acrylate, 13-hydroxypentadecyl (meth) acrylate, and 13- _{hydroxyC 13-20} alkane (meth) acrylate Ester; 14-hydroxytetradecyl (meth) acrylate, 14-hydroxydeca (meth) acrylate Esters of (meth) acrylic acid 14- hydroxy C _14-21 alkyl acrylate; (meth) acrylates fifteen 15-hydroxy esters, (meth) acrylic acid esters seventeen 15-hydroxy (meth) acrylate, 15-hydroxy C _15-22 alkyl esters and the like. Among these, from the viewpoint of durability, 5-hydroxypentyl (meth) acrylate, 5-hydroxyhexyl (meth) acrylate, 5-hydroxyheptyl (meth) acrylate, and (methyl) 5-hydroxyoctyl acrylate, 5-hydroxynonyl (meth) acrylate, and other hydroxyl-containing (meth) acrylates with n of 5, particularly preferably 5-hydroxypentyl (meth) acrylate.

In a preferred embodiment, the (meth) acrylic resin (B) contains a structural unit derived from the hydroxyl group-containing (meth) acrylate represented by the aforementioned (b1) and a unit derived from the aforementioned (b2) A constituent unit of a hydroxyl-containing (meth) acrylate. In this state, since the (meth) acrylic resin (B) has hydroxyalkyl groups with different carbon chain lengths (n and m) in the side chain, it is possible to more effectively suppress the interface peeling (or floating) in a high temperature environment. And foaming), and the durability of the adhesive layer formed of the adhesive composition can be further improved. Furthermore, even if the adhesive composition is used for a transparent electrode such as ITO, the durability under a high-temperature environment can be further improved. It is presumed that if the (meth) acrylic resin (B) is contained in the adhesive composition, the formed adhesive layer has a crosslinked structure and a crosslinked density that are most suitable for exhibiting good durability.

The ratio of the structural unit derived from the hydroxyl group-containing (meth) acrylate represented by the aforementioned formula (b1) to 100 mass parts of the total structural unit constituting the (meth) acrylic resin is preferably 1.5 to 5 mass Parts, more preferably 2 to 4.5 parts by mass, and a ratio derived from the constituent unit of the hydroxyl-containing (meth) acrylate represented by the aforementioned formula (b2), preferably 0.1 to 2 parts by mass, more preferably 0.25 to 1 part by mass. In addition, the ratio (mass ratio) of the structural unit derived from the hydroxyl-containing (meth) acrylate represented by formula (b1) to the structural unit derived from the hydroxyl-containing (meth) acrylate represented by formula (b2) ), As long as it is not particularly limited in the above range, it is preferably (b1) / (b2) = 13/1 to 3/1, more preferably 11/1 to 3/1, and still more preferably 9/1 to 4 / 1, particularly preferred is 7/1 to 5/1. If it is the said range, durability of an adhesive layer can be improved more.

Examples of heterocyclic group-containing (meth) acrylates include acrylamidomorphine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, and tetrahydrofuranmethyl (meth) acrylate Ester, caprolactone modified tetrahydrofuran methacrylate, 3,4-epoxycyclohexyl methyl (meth) acrylate, epoxypropyl (meth) acrylate, 2,5-dihydrofuran, etc. .

Examples of the (meth) acrylate containing a substituted or unsubstituted amine group include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, (methyl Group) dimethylaminopropyl acrylate and the like.

Examples of carboxyl-containing (meth) acrylates include (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, butenoic acid, carboxyalkyl (meth) acrylate (e.g., (methyl) ) Carboxyethyl acrylate, carboxypentyl (meth) acrylate) and the like. These carboxyl group-containing (meth) acrylates can be used alone or in combination of two or more. Moreover, from the viewpoint of preventing the peelability of the release film that may be laminated on the adhesive layer, it is preferable that the constituent unit derived from a monomer having an amine group is not substantially contained. The term "substantially free" refers to 100 parts by mass and less than 1.0 part by mass with respect to the total constituent units constituting the (meth) acrylic resin (B).

The proportion of the constituent units derived from the carboxyl group-containing (meth) acrylate is 1.0 part by mass or less with respect to 100 parts by mass of the total constituent units constituting the (meth) acrylic resin. The upper limit of the proportion of the constituent units derived from the carboxyl group-containing (meth) acrylate is preferably 0.5 parts by mass, more preferably 0.3 parts by mass, still more preferably 0.2 parts by mass, and particularly preferably 0.15 parts by mass. The lower limit of the proportion of the constituent units derived from the carboxyl group-containing (meth) acrylate is preferably 0 parts by mass, more preferably 0.001 parts by mass, still more preferably 0.005 parts by mass, particularly preferably 0.01 part by mass, The optimum is 0.05 parts by mass. The proportion of the constituent units derived from the carboxyl group-containing (meth) acrylate may be any combination of these upper and lower limits, and may be, for example, 0 to 1 part by mass, preferably 0 to 0.8 part by mass, It is more preferably 0.001 to 0.5 parts by mass, still more preferably 0.005 to 0.3 parts by mass, particularly preferably 0.01 to 0.2 parts by mass, and most preferably 0.05 to 0.15 parts by mass. If the proportion of the constituent unit derived from a carboxyl group-containing (meth) acrylate is equal to or less than the upper limit value, the corrosion resistance of a transparent electrode layer such as ITO can be suppressed, and if it is equal to or less than the lower limit value, durability can be improved.

Examples of the (meth) acrylamide-based monomer include N-methylol acrylamide, N- (2-hydroxyethyl) acrylamide, N- (3-hydroxypropyl) acrylamide, and N- (4-hydroxybutyl) acrylamide, N- (5-hydroxypentyl) acrylamide, N- (6-hydroxyhexyl) acrylamide, N, N-dimethylacrylamide, N, N -Diethylacrylamide, N-isopropylacrylamide, N- (3-dimethylaminopropyl) acrylamide, N- (1,1-dimethyl-3-oxobutane Propyl) acrylamidonium, N- [2- (2-oxo-1-imidazolidinyl) ethyl] acrylamidoamine, 2-propenylamino-2-methyl-1-propanesulfonic acid, N -(Methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (1-methylethoxymethyl) ) Acrylamide, N- (1-methylpropoxymethyl) acrylamide, N- (2-methylpropoxymethyl) acrylamide [alias: N- (isobutoxymethyl) ) Acrylamide], N- (butoxymethyl) acrylamide, N- (1,1-dimethylethoxymethyl) acrylamide, N- (2-methoxyethyl) Acrylamide, N- (2-ethoxyethyl) acrylamide, N- (2-propoxyethyl) acrylamide, N- [2- (1-methylethoxy) ethyl ] C Amidine, N- [2- (1-methylpropoxy) ethyl] propenamide, N- [2- (2-methylpropoxy) ethyl] propenamide [alias: N- ( 2-isobutoxyethyl) acrylamide], N- (2-butoxyethyl) acrylamide, N- [2- (1,1-dimethylethoxy) ethyl] propene Amidine and so on. By including a structural unit derived from a (meth) acrylamide-based monomer, the durability of the adhesive layer can be further improved. In particular, among these, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, N- (2-methylpropoxymethyl) acrylamide, and the like.

The proportion of the constituent units derived from the (meth) acrylamide-based monomer is preferably 5 parts by mass or less with respect to 100 parts by mass of the total constituent units constituting the (meth) acrylic resin. The upper limit of the proportion of the constituent units derived from the (meth) acrylamide-based monomer is preferably 3 parts by mass, more preferably 2 parts by mass, and even more preferably 1 part by mass. The lower limit value of the proportion of the constituent units derived from the (meth) acrylamide-based monomer is preferably 0 parts by mass, more preferably 0.001, still more preferably 0.01 part by mass, and particularly preferably 0.1 part by mass. The proportion of the constituent units derived from the (meth) acrylamide-based monomer may be any combination of the upper limit value and the lower limit value, and may be, for example, 0 to 5 parts by mass, preferably 0.001 to 3 parts by mass. It is more preferably 0.01 to 2 parts by mass, and still more preferably 0.1 to 1 part by mass. If the proportion of the constituent units derived from the (meth) acrylamide-based monomer is within the above range, the durability of the adhesive layer can be further improved.

Examples of the styrene-based monomer include styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, Alkyl styrenes such as butylstyrene, hexylstyrene, heptylstyrene, octylstyrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; nitrate Styrene; ethyl styrene; methoxystyrene; divinylbenzene and the like.

Examples of the vinyl-based monomer include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl valerate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halides such as vinyl chloride and bromoethylene; and dichloro Vinylidene halides such as vinylene; nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; conjugated diene monomers such as butadiene, isoprene, and chloroprene; acrylonitrile, methyl Unsaturated nitriles such as acrylonitrile.

Monomers having plural (meth) acrylfluorene groups in the molecule include, for example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1 , 9-nonanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, three Propylene glycol di (meth) acrylate is equivalent to a monomer with 2 (meth) acryl groups in the molecule; trimethylolpropane tri (meth) acrylate is equivalent to 3 (meth) acryl groups in the molecule Monomer.

Examples of the alkyl acrylate include alkyl acrylate (b3) having a glass transition temperature (Tg) of the homopolymer of less than 0 ° C, and alkyl acrylate (b4) having a Tg of the homopolymer of 0 ° C or more.

The alkyl acrylate (b3) of which the glass transition temperature (Tg) of the homopolymer does not reach 0 ° C can be exemplified by ethyl acrylate, n- and iso-propyl acrylate, n- and iso-butyl acrylate, n-amyl acrylate, and acrylic acid. Carbon number of alkyl groups such as n-hexyl acrylate, n-heptyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n- and isononyl acrylate, n- and isodecyl acrylate, and n-dodecyl acrylate Linear or branched alkyl acrylates, etc., from about 2 to about 12. The alkyl acrylate (b3) can also be an alkyl acrylate (cycloalkyl acrylate) having an alicyclic structure. From the viewpoint of followability (or flexibility or adhesion) to the optical film, etc. Alkyl esters having a number of 2 to 10 are preferred, 3 to 8 alkyl esters having a carbon number of acrylic acid, 4 to 6 alkyl esters having a carbon number of acrylic acid, and n-butyl acrylate is particularly preferred. When n-butyl acrylate is used, followability can be improved, and for example, it is advantageous in peel resistance. These alkyl acrylates (b3) can be used individually or in combination of 2 or more types.

The alkyl acrylate (b4) of which the homopolymer has a Tg of 0 ° C or higher can be exemplified by methyl acrylate, cycloalkyl acrylate (such as cyclohexyl acrylate, isoamyl acrylate), stearyl acrylate, and triacrylate Grade butyl and the like are particularly preferably methyl acrylate. When methyl acrylate is used, the strength can be increased, which is advantageous for, for example, agglutination failure. These alkyl acrylates (b4) can be used individually or in combination of 2 or more types. For the Tg of the homopolymer of the alkyl acrylate, refer to, for example, a literature value such as POLYMER HANDBOOK (Wiley-Interscience).

In a preferred aspect, from the viewpoint of improving the durability of the adhesive layer, the (meth) acrylic resin (A) contains an alkyl acrylate (b3) derived from a homopolymer with a glass transition temperature of less than 0 ° C. And a constituent unit of an alkyl acrylate (b4) having a glass transition temperature of 0 ° C or higher derived from a homopolymer. If an acrylic acid alkyl ester whose Tg is less than 0 ° C and an acrylic acid alkyl ester whose Tg is 0 ° C or more are used in combination, both the resistance to aggregation damage and the followability (foaming resistance and resistance Releasability), and can improve durability against dimensional changes of optical films (such as polarizing plates).

The proportion of the constituent units derived from the alkyl acrylate in the (meth) acrylic resin (B) is considered from the viewpoint of durability and reworkability of the adhesive layer to the (meth) acrylic resin (B 100 parts by mass, preferably 40 parts by mass or more, more preferably 50 parts by mass or more, still more preferably 60 parts by mass or more, particularly preferably 70 parts by mass or more, and most preferably 80 parts by mass or more, It is preferably 98 parts by mass or less, more preferably 95 parts by mass or less, and still more preferably 90 parts by mass or less. Any combination of the lower limit value and the upper limit value may also be used, for example, 50 to 98 parts by mass, It is preferably 70 to 95 parts by mass, and more preferably 80 to 90 parts by mass.

The constituent units of the alkyl acrylate (b3) derived from the homopolymer with a glass transition temperature of less than 0 ° C and the constituent units of the alkyl acrylate (b4) derived from the homopolymer with a glass transition temperature of 0 ° C or higher Ratio (mass ratio), preferably (b3) / (b4) = 20/80 to 95/5, more preferably 30/70 to 90/10, still more preferably 30/70 to 85/15, particularly good From 30/70 to 70/30. If it is the said range, durability will be improved more. The larger the proportion of the constituent units derived from the alkyl acrylate (b3) having a glass transition temperature of less than 0 ° C, the higher the followability. The larger the proportion of the constituent units derived from the alkyl acrylate (b4) having a glass transition temperature of 0 ° C or higher, the higher the resistance to aggregation and destruction.

Examples of the substituent-containing alkyl acrylate include alkyl acrylates in which a substituent is introduced into the alkyl group in the aforementioned alkyl acrylate (a hydrogen atom of the alkyl group is substituted with a substituent). Examples of the substituent include aryl (such as phenyl), aryloxy (such as phenoxy), and alkoxy (such as methoxy and ethoxy). Examples of the alkyl acrylate having a substituent include alkoxy acrylate (e.g., 2-methoxyethyl acrylate, ethoxymethyl acrylate, etc.), aryl alkyl acrylate (e.g., benzyl acrylate) Esters, etc.), aryloxyalkyl acrylates (eg, phenoxyethyl acrylate, etc.), aryloxy polyalkylene glycol monoacrylates, polyalkylene glycol monoacrylates, and the like. These substituent-containing alkyl acrylates can be used alone or in combination of two or more kinds. By containing an alkyl acrylate containing an aromatic ring such as an aryl group, a benzyl group, and an aryloxy group, the white spots of the polarizing plate in the durability test can be improved. Moreover, by including an alkoxy group, an aryloxy group, etc., the antistatic property when an antistatic agent is added to an adhesive layer can be improved. The alkylene group of aryloxy polyalkylene glycol monoacrylate and polyalkylene glycol monoacrylate may be, for example, C _1-6 alkylene groups such as methylene, ethylene, and propyl (preferably Considering the viewpoint of the balance between the durability and antistatic property of the adhesive layer formed of the adhesive composition, the repeating unit of the alkylene group is, for example, 1 to 7, preferably 1 to 5, Particularly preferred is 1 to 2. Specifically, for example, phenoxy di-acrylic acid di-7 to C _1-3 alkylene glycols such as phenoxy diethylene glycol acrylate, mono-di-acrylic acid di ₁ to 7 C ₁ such as diethylene glycol monoacrylate, etc. _-3 alkylene glycol ester and the like. The alkyl acrylate containing a substituent used in the present invention is particularly preferably phenoxyethyl acrylate and phenoxydiethylene glycol from the viewpoint of balance between durability, white spot resistance, and antistatic property. ester.

The proportion of the constituent units derived from the alkyl acrylate containing a substituent is, for example, 0 to 30 parts by mass, and preferably 1 to 100 parts by mass relative to the total constituent units constituting the (meth) acrylic resin (B). 25 parts by mass, more preferably 3 to 20 parts by mass, and still more preferably 5 to 15 parts by mass.

In order to improve the durability of the adhesive layer, the weight average molecular weight (Mw) of the (meth) acrylic resin (B) in terms of standard styrene obtained by gel permeation chromatography GPC is preferably 1 million or more. The lower limit of Mw is more preferably 1.1 million, more preferably 1.2 million, and particularly good 1.3 million. The upper limit value of Mw is not particularly limited, but from the viewpoint of coating properties when the adhesive composition is processed into a sheet shape (coated on a substrate), it is preferably 2.5 million, more preferably 2.2 million, More preferably, it is 2 million. Mw can also be any combination of these upper and lower limits, such as 1 to 2.5 million, more preferably 1.1 to 2.2 million, and still more preferably 1.3 to 2 million. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is usually 2 to 10, preferably 3 to 8, and more preferably 4 to 6.

The (meth) acrylic resin (B) preferably has a single peak in the range of Mw on the GPC discharge curve of 1.0 × 10 ³ to 2.5 × 10 ⁶ . Use of the (meth) acrylic resin (B) having a peak number of 1 is advantageous for improving the durability of the adhesive layer.

The so-called “having a single peak” in the above range of the obtained flow curve means that there is only one maximum value in the range of Mw from 1.0 × 10 ³ to 2.5 × 10 ⁶ . In this specification, the GPC flow curve defines a peak with an S / N ratio of 30 or more. The number of peaks of the GPC flow curve and the Mw and Mn of the (meth) acrylic resin (B) can be determined under the GPC measurement conditions described in the examples.

When the (meth) acrylic resin (B) is dissolved in ethyl acetate to make a solution having a concentration of 20% by mass, the viscosity at 25 ° C. is preferably 20 Pa · s or less, and more preferably 0.1 to 7 Pa · s. If the viscosity is within this range, it is advantageous from the viewpoint of the applicability when the adhesive composition is applied to a substrate. The viscosity can be measured with a Brookfield viscometer.

The glass transition temperature (Tg) of the (meth) acrylic resin (B) is, for example, -60 to 0 ° C, preferably -50 to -10 ° C, more preferably -50 to -20 ° C, and even more preferably -40 to -20 ° C, particularly preferably -40 to -25 ° C. If Tg is in the above range, it is advantageous to improve the durability of the adhesive layer. The glass transition temperature can be measured by a differential scanning thermal analyzer (DSC).

The (meth) acrylic resin (B) can be produced by a known method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method, and a solution polymerization method is particularly preferred. The solution polymerization method may be, for example, the following method: mixing a monomer and an organic solvent, adding a thermal polymerization initiator under a nitrogen atmosphere, and stirring at a temperature of about 40 to 90 ° C, preferably about 50 to 80 ° C 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 and the thermal polymerization initiator may be added to an organic solvent.

As the polymerization initiator, a thermal polymerization initiator or a photopolymerization initiator can be used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) one and the like. Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane- 1-nitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile) Azo compounds such as 2,2'-azobis (2-methylpropionic acid) dimethyl ester, 2,2'-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, Tertiary butyl hydroperoxide, benzoyl peroxide, tertiary butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, peroxidation Organic peroxides such as tert-butyl neodecanoate, tert-butyl pervalerate, (3,5,5-trimethylhexyl) peroxide; potassium persulfate, ammonium persulfate, Inorganic peroxides such as hydrogen peroxide. Further, a redox-based initiator such as a peroxide and a reducing agent may be used in combination.

The proportion 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 active energy rays (for example, ultraviolet rays) can also be used.

Examples of organic solvents include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aromatic alcohols such as propanol and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone Class, etc.

[1-3] Crosslinking agent (C)

The adhesive composition may contain a crosslinking agent (C). This crosslinking agent (C) reacts with a reactive group (for example, a hydroxyl group) in the (meth) acrylic resin (B). The cross-linking agent (C) forms a cross-linked structure with a (meth) acrylic resin, and forms a cross-linked structure that is advantageous for durability and reworkability.

Examples of the cross-linking agent (C) include conventional cross-linking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelates, peroxides, etc.), and in particular, they are suitable for use with adhesive compositions. From the viewpoint of the durability and the crosslinking speed of the adhesive layer, an isocyanate compound is preferred.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, and examples thereof include aliphatic isocyanate compounds (for example, hexamethylene diisocyanate, etc.), and alicyclic isocyanate compounds (for example, isocyanate Phorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate), aromatic isocyanate compounds (such as toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate , Triphenylmethane triisocyanate) and the like. The cross-linking agent (C) may be an adduct of an isocyanate compound polyol (for example, an adduct of glycerol, trimethylolpropane, etc.), a trimeric isocyanate compound, or a polycondensate. Biuret type compound, polyether alcohol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. Derivatives such as isocyanate compounds. Crosslinked fluorene (C) can be used alone or in combination of two or more kinds. Among these, representative examples include aromatic isocyanate compounds (for example, toluene diisocyanate, xylene diisocyanate), aliphatic isocyanate compounds (for example, hexamethylene diisocyanate), or a plurality thereof. An adduct of an alcohol compound (for example, glycerol, trimethylolpropane), or a trimeric isocyanate. Crosslinking 剤 (C) is an adduct made of an aromatic isocyanate compound and / or a polyhydric alcohol compound or a trimeric isocyanate, which is advantageous for forming an optimal crosslink density (or crosslinked structure). ), So the durability of the adhesive layer can be improved. In particular, if it is an adduct of a toluene diisocyanate-based compound and / or a polyol compound thereof, the durability can be improved even when the adhesive layer is used for a transparent electrode.

The proportion of crosslinked fluorene (C) is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more, based on 100 parts by mass of the (meth) acrylic resin (B), Particularly preferred is 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, particularly preferred 2 parts by mass or less, extremely It is preferably 1 part by mass or less, most preferably 0.8 part by mass, or any combination of the lower limit value and the upper limit value, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, more It is preferably 0.1 to 3 parts by mass, still more preferably 0.1 to 2 parts by mass, particularly preferably 0.2 to 1 part by mass, and most preferably 0.3 to 0.8 part by mass. If it is more than the upper limit value, it is advantageous to improve the followability (or peel resistance), and if it is more than the lower limit value, it is advantageous to improve the aggregation resistance (or foam resistance) or reworkability.

[1-4] Silane compound (D)

The adhesive composition may contain a silicone compound (D) other than the silicone compound (A).

The silane compound (D) may be a silane compound capable of bonding with a reactive group (for example, a hydroxyl group) of the (meth) acrylic resin (B), and is preferably a silane compound having at least one alkoxy group in the molecule. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (2-methoxyethoxy) silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidyl Oxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2- (3,4-ethyl (Oxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropane Trimethoxysilane, 1,3-bis (3'-trimethoxypropyl) urea, and the like.

The silane compound (D) may be a polysiloxane oligomer type compound. If the polysiloxane oligomer is represented by a combination of monomers, for example, 3-mercaptopropylditrim or trimethoxy Silane-tetramethoxysilane oligomer, 3-mercaptomethyldi or trimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyldi or triethoxysilane-tetramethoxysilane oligomer, 3 -Mercaptomethyl bis- or triethoxysilane-tetraethoxysilane oligomers and other oligomers containing mercaptoalkyl groups; the mercaptoalkyl group of the mercaptoalkyl group-containing oligomers with other substituents [3- Glycidoxypropyl, (meth) acryloxypropyl, vinyl, amine, etc.] substituted oligomers.

[1-5] Antistatic agent

The adhesive composition may further contain an antistatic agent. By including an antistatic agent, the antistatic property of the adhesive can be improved (for example, it is possible to suppress adverse conditions caused by static electricity generated when peeling a release film, a protective film, etc.). The antistatic agent may be, for example, a conventional one, and an ionic antistatic agent is preferred. Examples of the cationic component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of the organic cation include a pyridine cation, an imidazole cation, an ammonium cation, a sulfonium cation, a sulfonium cation, and the like. Examples of the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. The anionic component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, and an anionic component containing a fluorine atom is preferred because of its excellent antistatic performance. An anionic component containing a fluorine atom includes, for example hexafluorophosphate anion (PF ₆ ^-), bis (trifluoromethane sulfonic acyl) imide anion _{[(CF 3 SO 2) 2} N -], bis (fluoromethyl sulfonylurea yl) imide anion ^{_{[(FSO 2) 2 N -}} ], tetrakis (pentafluorophenyl) borate anion _{[(C 6 F 5) 4} B -] and the like. These antistatic agents can be used alone or in combination of two or more. In particular, bis (trifluoromethane sulfonic acyl) imide anion _{[(CF 3 SO 2) 2} N -], bis (sulfo-fluoro-acyl) imide anion ^{_{[(FSO 2) 2 N -}} ], tetrakis (pentafluoro phenyl) borate anion _{[(C 6 F 5) 4} B -] is preferred. From the viewpoint that the antistatic property of the adhesive layer formed of the adhesive composition is excellent in stability over time, an ionic antistatic agent which is solid at room temperature is preferable.

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

Even if the adhesive composition of the present invention contains an antistatic agent, it exhibits good durability in a high temperature environment. Therefore, it is possible to achieve both good durability and antistatic performance.

[1-6] Other ingredients

The adhesive composition may contain additives such as solvents, cross-linking catalysts, ultraviolet absorbers, weather stabilizers, tackifiers, plasticizers, softeners, dyes, pigments, inorganic fillers, light-scattering particles, etc. alone or in combination . Further, if an ultraviolet curable compound is blended in the adhesive composition and irradiated with ultraviolet rays after the adhesive layer is formed to harden, a harder adhesive layer can be formed. Examples of the crosslinking catalyst include hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, Amine compounds such as polyamine resins and melamine resins.

From the viewpoint of improving the metal corrosion resistance of the adhesive layer, the adhesive composition may contain a rust inhibitor. Examples of the rust inhibitor include triazole compounds such as benzotriazole compounds; thiazole compounds such as benzothiazole compounds; imidazole compounds such as benzimidazole compounds; imidazoline compounds; quinoline compounds; pyridine Based compounds; pyrimidine based compounds; indole based compounds; amine based compounds; urea based compounds; sodium benzoate; benzyl mercaptothio compounds; di-secondary butyl sulfide;

In a preferred aspect, the adhesive composition of the present invention does not substantially contain a photopolymerization initiator and its decomposition products. This is because the photopolymerization initiator and its decomposition product in the adhesive composition may hinder the formation of an adhesive layer having excellent durability. Here, the term “does not substantially contain” means that the content is 1.0 part by mass or less with respect to 100 parts by mass of the adhesive composition, preferably 0.1 part by mass or less, more preferably 0.01 part by mass or less, and even more preferably 0.001 part. It is most preferably 0 parts by mass or less.

[2] Composition and manufacturing method of adhesive layer and optical film with adhesive layer

The present invention includes an adhesive layer composed of the aforementioned adhesive composition. The adhesive layer can be formed, for example, by dissolving or dispersing the aforementioned adhesive composition in a solvent to form a solvent-containing adhesive composition, and then coating the surface of an optical film or a release film and drying it.

The present invention also includes an optical film with an adhesive layer obtained by laminating an adhesive on at least one side of the optical film.

Since the adhesive layer of the present invention and the optical film with the adhesive layer are formed of the aforementioned adhesive composition, even when used (or laminated) on a transparent electrode layer such as ITO, it can be used under severe and durable conditions. Has excellent durability.

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

When the adhesive layer 20 is laminated on the surface of the optical film 10, it is preferable to form a primer layer on the bonding surface of the optical film 10 and / or the bonding surface of the adhesive layer, or apply the aforementioned surface activation treatment ( (E.g., plasma treatment, corona treatment, etc.), and particularly preferably corona treatment.

When the optical film 10 is a single-sided protective polarizing plate as shown in FIG. 2, the adhesive layer 20 is usually laminated (preferably directly laminated) on the surface of the polarizer, that is, the polarizer 2 is opposite to the first resin film 3 Side surface. When the optical film 10 is a double-sided protective polarizing plate as shown in FIG. 3, the adhesive layer 20 may be laminated on the outer surface of any one of the first and second resin films 3 and 4, or may be laminated on the outer surface of either one. surface.

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

The optical film 1 with an adhesive layer may contain a release film (release film) laminated on the outer surface of the adhesive layer. This isolation film is usually peeled and removed when the adhesive layer 20 is used (for example, when laminated on a transparent electrode or a glass substrate). For example, the release film may be formed on the surface of the adhesive layer 20 of a thin film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate. Those who take off the film such as silica treatment.

The optical film 1 with an adhesive layer can dissolve or disperse each component constituting the above-mentioned adhesive composition in a solvent to make a solvent-containing adhesive composition, and then apply it to the surface of the optical film 10 and dry it. An adhesive layer 20 is formed, thereby being manufactured. The optical film 1 with an adhesive layer can also be formed by laminating (transferring) the adhesive layer 20 on the surface of the optical film 10 by forming the adhesive layer 20 in the same manner as described above due to the release treatment surface of the release film. be made of.

The thickness of the adhesive layer is usually 2 to 40 μm. From the viewpoint of the durability of the optical film with the adhesive layer or the reworkability of the optical film with the adhesive layer, it is preferably 5 to 30 μm, more preferably 10 to 25 μm. If the thickness of the adhesive layer is equal to or less than the above-mentioned upper limit value, the reworkability is good, and if it is equal to or more than the above-mentioned lower limit value, the followability to the dimensional change of the optical film is good.

The adhesive layer is preferably one that exhibits a storage elastic modulus of 0.001 to 10 MPa in a temperature range of 23 to 120 ° C. Thereby, the durability of the optical film with an adhesive layer can be improved more effectively. The so-called "displaying a storage elastic modulus in a temperature range of 23 to 120 ° C from 0.001 to 10 MPa" means that at any temperature in the range, the storage elastic modulus is a value within the above range. The storage elastic modulus usually decreases with increasing temperature. Therefore, if the storage elastic modulus at 23 ° C and 120 ° C is within the above range, it can be estimated that the temperature in this range shows the storage in the above range. Modulus of elasticity. The storage elastic modulus of the adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device "DYNAMIC ANALYXER RDA II" manufactured by REOMETRIC.

The viscose fraction can be used as an indicator of the crosslinking density. Since the adhesive layer of the present invention has a predetermined crosslinking density, it exhibits a predetermined gel fraction. That is, the gel fraction of the adhesive layer of the present invention may be, for example, 70 to 90% by mass, preferably 75 to 90% by mass, and more preferably 75 to 85% by mass. If the gel fraction is above the lower limit value, it is beneficial to the foaming resistance and reworkability of the adhesive layer, and if the gel fraction is below the upper limit value, it is beneficial to the peeling resistance of the adhesive layer. The gel fraction can be measured by the method described in the examples.

The optical film with an adhesive layer of the present invention has a predetermined adhesive force and is excellent in reworkability. That is, the adhesive layer on the surface of the optical film with an adhesive layer not bonded to the optical film is bonded to a glass substrate, and the adhesive is stored for 24 hours at a temperature of 23 ° C. and a relative humidity of 50%. The peeling force is 300 mm / min, preferably 0.5 to 10 N / 25 mm, and more preferably 0.7 to 5 N / 25 mm. If the adhesive force is above the lower limit value, the adhesiveness (or adhesiveness) is improved, which is advantageous for peel resistance, and if the adhesive force is below the upper limit value, it is advantageous for reworkability. The adhesive force can be measured, for example, by the method described in the examples.

[2-1] Optical film

The optical film 10 constituting the optical film 1 with an adhesive layer may be various optical films (films having optical characteristics) that can be assembled in an image display device such as a liquid crystal display device. The optical film 10 may have a single-layer structure (such as a polarizing film, a retardation film, a brightness enhancement film, an anti-glare film, an anti-reflection film, a diffusion film, a light-condensing film and other optical functional films), or a multilayer structure ( (Such as polarizing plates, retardation plates, etc.). The optical film 10 is preferably a polarizer, a polarizer, a retardation film or a retardation film, and particularly preferably a polarizer or a polarizer. In this specification, the term "optical film" means a film (for example, a film having a function of improving the visibility of an image) having a function for displaying an image (a display screen, etc.). In this specification, a polarizing plate refers to a resin film or a resin layer on at least one area layer of a polarizer, and a retardation plate refers to a resin film or a resin layer on at least one area layer of a retardation film.

[2-2] polarizing plate

2 and 3 are schematic cross-sectional views showing examples of the layer configuration of the polarizing plate. The polarizing plate 10a shown in FIG. 2 is a one-sided protective polarizing plate of the first resin film 3 on a surface area layer (or laminated layer) of the polarizer 2 and the polarizing plate 10b shown in FIG. 3 is polarized The other surface of the sheet 2 is further laminated (or laminated) with a double-sided protective polarizer of the second resin film 4. The first and second resin films 3 and 4 can be bonded to the polarizer 2 through an adhesive layer or an adhesive layer (not shown). The polarizing plates 10 a and 10 b may include other films or layers other than the first and second resin films 3 and 4.

The polarizer 2 is a film having the following properties: linearly polarized light that absorbs a vibration plane parallel to its absorption axis, and linearly polarized light that transmits a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). For example, it can be used for polyvinyl alcohol. A resin film is a film in which a dichroic dye is adsorbed and aligned. Examples of the dichroic pigment include iodine or a dichroic organic dye.

The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. Polyvinyl acetate resins include, for example, polyvinyl acetate which is a homopolymer of vinyl acetate, and monomers which can be copolymerized with vinyl acetate (e.g., unsaturated carboxylic acid, olefin, vinyl ether, unsaturated sulfonic acid, etc.) (A copolymer of (meth) acrylamide having an ammonium group) and vinyl acetate.

The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl aldehyde or polyvinyl acetal modified by aldehydes. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, and preferably 1500 to 5,000. The average degree of polymerization of the polyvinyl alcohol-based resin can be obtained in accordance with JIS K 6726.

Generally, a film made of a polyvinyl alcohol resin is used as the original film of the polarizer 2. The polyvinyl alcohol-based resin can be formed into a film by a known method. The thickness of the original film is usually 1 to 150 μm, and in consideration of ease of extension, etc., it is preferably 10 μm or more.

The polarizer 2 can be subjected to, for example, a step of uniaxially stretching the original film, a step of dyeing the film with a dichroic pigment to adsorb the dichroic pigment, a step of treating the film with an aqueous solution of boric acid, and a film The step of washing with water, and finally drying to manufacture. The thickness of the polarizer 2 is usually 1 to 30 μm, and from the viewpoint of thinning the optical film 1 with an adhesive layer, it is preferably 20 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less.

The polarizer 2 made of a dichroic pigment adsorbed and aligned with a polyvinyl alcohol resin film can be produced by using a separate film of a polyvinyl alcohol resin film as an original film, and applying a single film to the film. A method (method (1)) of a shaft stretching treatment and a dichroic dyeing treatment, and further, coating a coating solution (aqueous solution, etc.) containing a polyvinyl alcohol resin on a base film, and drying to obtain a polymer After the base film of the vinyl alcohol resin layer, each of the base films is uniaxially stretched, the stretched polyvinyl alcohol resin layer is subjected to a dichroic dyeing treatment, and then the base film Method of peeling and removing (method (2)). The base film can be a thin film made of a thermoplastic resin and the same thermoplastic resin that can form the first and second resin films 3 and 4 described later. Polyester resins such as polyethylene terephthalate, A film composed of a polycarbonate resin, a cellulose resin such as polyethylene cellulose, a cyclic polyolefin resin such as norbornene resin, and a polystyrene resin. When the method (2) is used, production of the thin film polarizer 2 becomes easy, and for example, production of the polarizer 2 having a thickness of 7 μm or less can be easily performed.

The first and second resin films 3 and 4 are each independently a resin film having translucency. The first and second resin films 3 and 4 are preferably optically transparent thermoplastic resins. For example, the first and second resin films 3 and 4 may be a chain polyolefin resin (for example, a polyethylene resin, a polypropylene resin, etc.) or a ring. Polyolefin resins such as polyolefin resins (such as norbornene resins); cellulose resins (such as cellulose ester resins); polyester resins (such as polyethylene terephthalate, polynaphthalene Ethylene formate, polybutylene terephthalate, etc.); polycarbonate resins (such as 2,2-bis (4-hydroxyphenyl) propane-based polycarbonates derived from bisphenols, etc.); (methyl ) Acrylic resins; polystyrene resins; polyetheretherketone resins; polyfluorene resins, or mixtures and copolymers of these films. Among these, the first and second resin films 3 and 4 are each preferably made of a cyclic polyolefin resin, a polycarbonate resin, a cellulose resin, a polyester resin, and a (meth) acrylic resin. A film made of a resin or the like is particularly preferably a film made of a cellulose-based resin, a cyclic polyolefin-based resin, or the like.

Examples of the chain polyolefin resin include homopolymers of chain olefins such as polyethylene resins and polypropylene resins, and copolymers of two or more chain olefins.

The cyclic polyolefin-based resin may include, for example, a cyclic polyolefin including norbornene or tetracyclododecene (alias: dimethanooctahydronaphthalene) or a derivative thereof as a representative unit. Generic term for resin. Examples of the cyclic polyolefin resin include ring-opening (co) polymers of cyclic olefins and their hydrogenated products, addition polymers of cyclic olefins, cyclic olefins and chain olefins such as ethylene and propylene, or vinyl groups. Copolymers of aromatic compounds, and modified (co) polymers modified with unsaturated carboxylic acids or derivatives thereof. Among these, the cyclic olefin is preferably a norbornene-based resin using a norbornene-based monomer such as norbornene and a polycyclic norbornene-based monomer.

The fiber-based resin is preferably a cellulose ester-based resin, that is, a partial or complete esterification of cellulose, and examples thereof include cellulose acetate, propionate, butyrate, and mixed esters thereof. Among these, triethyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like are preferred.

Polyester-based resins are resins other than the above-mentioned cellulose ester-based resins having an ester bond, and are generally a polycondensate of a polycarboxylic acid or a derivative thereof with a polyhydric alcohol. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, and polynaphthalene Propylene formate, cyclohexane dimethyl polyphthalate, cyclohexane dimethyl polynaphthalate, and the like.

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

The (meth) acrylic resin that can constitute the first and second resin films 3 and 4 can be a polymer mainly composed of a methacrylate-derived unit (for example, containing 50% by mass or more of the unit). A copolymer in which this constituent unit is copolymerized with another copolymerization component is preferred. The (meth) acrylic resin may contain two or more kinds of constituent units derived from a methacrylate. Examples of the methacrylate include C ₁ to C ₄ alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

Examples of the copolymerizable component that can be copolymerized with methacrylate include acrylate. The acrylate is preferably a C ₁ to C ₈ alkyl ester of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, or 2-ethylhexyl acrylate. Specific examples of other copolymerization components include unsaturated acids such as (meth) acrylic acid; aromatic vinyl compounds such as styrene, halogenated styrene, α-methylstyrene, and vinyl toluene; and (meth) acrylonitrile Ethylene cyanide compounds; Unsaturated acid anhydrides such as maleic anhydride and pyrocitric anhydride; Unsaturated hydrazones such as phenylmaleimide and cyclohexylmaleimide are equivalent to having a polymerizable carbon-carbon double bond in the molecule Other than acrylates. A compound having two or more polymerizable carbon-carbon double bonds in the molecule may be used as a copolymerization component. The copolymerization component can be used alone or in combination of two or more.

From the viewpoint of improving the durability of the film, the (meth) acrylic resin may have a ring structure in the polymer main chain. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic amidine structure, and a lactone ring structure. Specific examples of the cyclic acid anhydride structure include glutaric anhydride structure and succinic anhydride structure, and specific examples of the cyclic fluorene imine structure include glutarium imidate structure and succinimine structure. Lactone Specific examples of the 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 and impact resistance of the film. The acrylic rubber particles refer to particles having an elastic polymer mainly composed of acrylate as an essential component, and may be, for example, a single-layered structure composed of only the elastic polymer or a layer of the elastic polymer. Multi-layer constructor. Examples of the elastic polymer include, for example, a crosslinked elastic copolymer mainly composed of an alkyl acrylate and copolymerized with other ethylene monomers and crosslinkable monomers copolymerizable therewith. Examples of the alkyl acrylate of the main component of the elastic polymer include C ₁ to C ₈ alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The carbon number of the alkyl group is preferably 4 or more.

Other vinyl monomers that can be copolymerized with alkyl acrylates are, for example, compounds having a polymerizable carbon-carbon double bond in the molecule, and more specifically, for example, methyl groups such as methyl methacrylate Acrylates, aromatic vinyl compounds such as styrene, vinyl cyanide compounds such as (meth) acrylonitrile, and the like. Examples of the crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule, and more specifically, ethylene glycol di (meth) acrylate, butane Polyol (meth) acrylates such as alcohol di (meth) acrylates, olefin esters of (meth) acrylic acid such as allyl (meth) acrylates, divinylbenzene, and the like.

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. If the content of the acrylic rubber particles is too large, the surface hardness of the film will decrease, and when the film is subjected to a surface treatment, the solvent resistance to the organic solvent in the surface treatment agent will be reduced. Therefore, the content of the acrylic rubber particles is usually 80 parts by mass or less, and preferably 60 parts by mass based on 100 parts by mass of the (meth) acrylic resin.

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

The first and second resin films 3 and 4 may be either unstretched films or uniaxially or biaxially stretched films. The first resin film 3 and / or the second resin film 4 may be a protective film that functions as a protective polarizer 2, or a protective film that also has optical functions, such as a retardation film described later.

In addition, the first resin film 3 and / or the second resin film 4 may include a hard shell layer, an anti-glare layer, an anti-reflection layer, a light diffusion layer, and an outer surface (a surface opposite to the polarizer 2). Surface treatment layer (coating layer) such as antistatic layer, antifouling layer, and conductive layer. The thickness of the first resin film 3 and the second resin film 4 are generally 1 to 150 μm, preferably 5 to 100 μm, more preferably 5 to 60 μm, and still more preferably 50 μm or less (for example, 1 to 40 μm). It is preferably 30 μm or less (for example, 5 to 25 μm).

In particular, for thin and medium-sized polarizers such as smartphones and tablet terminals, thin films with a thickness of 30 μm or less are often used as the first resin film 3 and / or the second resin film 4 due to thin film requirements. The restraining force of the shrinking force of the polarizing plate-based polarizer 2 is weakened, and durability is liable to become insufficient. Even when such a polarizing plate is used as the optical film 10, the optical film 1 with an adhesive layer of the present invention has good durability.

The first and second resin films 3 and 4 can be bonded to the polarizer 2 through 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 composed of an aqueous solution of a polyvinyl alcohol resin, an aqueous two-liquid urethane emulsion adhesive, an aldehyde compound, an epoxy compound, a melamine compound, (Methylol compounds, isocyanate compounds, amine compounds, cross-linking agents such as polyvalent metal salts, etc.). Among these, a water-based adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin is preferably used. When a water-based adhesive is used, it is preferable to perform a drying step for removing water contained in the water-based adhesive after the polarizer 2 and the first and second resin films 3 and 4 are bonded together. After the drying step, a curing step for curing at a temperature of, for example, about 20 to 45 ° C. may be provided.

The above-mentioned active energy ray-curable adhesive refers to an adhesive that is cured by irradiating active energy rays such as ultraviolet rays or electron rays, and examples thereof include a curable composition containing a polymerizable compound and a photopolymerization initiator, and a photoreaction. The curable composition of the curable resin, the curable composition of the binder-containing resin, and the photoreactive crosslinker are preferably ultraviolet curable adhesives.

When an active energy ray hardening adhesive is used, after attaching the polarizer 2 and the first and second resin films 3 and 4, a drying step is performed as necessary, and then the active energy ray is irradiated to harden the active energy ray. Agent hardening step. The light source of the active energy ray is not particularly limited, but is preferably an ultraviolet ray having a light emission distribution at a wavelength of 400 nm or less.

For the method of bonding the polarizer 2 and the first and second resin films 3 and 4, for example, a surface activation treatment such as saponification treatment, corona treatment, or plasma treatment may be applied to the bonding surface on at least one of these sides. Methods etc. When the resin films are laminated on both sides of the polarizer 2, the adhesive used to adhere the resin films may be the same type of adhesive or different types of adhesives.

The polarizing plates 10a and 10b may further contain other films or layers. Specific examples thereof include, in addition to the retardation film described later, a brightness enhancement film, an anti-glare film, an anti-reflection film, a diffusion film, a light-condensing film, and an adhesive layer, a coating layer, a protective film, etc. other than the adhesive layer 20. . The protective film is a film used to protect the surface of the optical film 10 such as a polarizing plate from being damaged or soiled. Generally, the optical film 1 with an adhesive layer, for example, is attached to a metal layer or a substrate and then peeled off.

The protective film is generally composed of a base film and an adhesive layer laminated on the base film. The base film can be made of thermoplastic resins such as polyolefin resins such as polyethylene resins and polypropylene resins; polyester resins such as polyethylene terephthalate or polyethylene naphthalate; polycarbonate resins; (Meth) acrylic resin.

[2-3] Phase difference plate

The retardation film included in the retardation plate, such as the above-mentioned optical film showing optical anisotropy, can be used for the first and second resin films 3 and 4, in addition to the thermoplastic resins exemplified above, it can be For example, polyvinyl alcohol-based resin, polyacrylate-based resin, polyimide-based resin, polyether fluorene-based resin, polyvinylidene fluoride / polymethyl methacrylate-based resin, liquid crystal polyester-based resin, ethylene- A stretched film obtained by stretching a resin film composed of a vinyl acetate copolymer saponified product, a polyvinyl chloride-based resin, or the like by about 1.01 to 6 times. Among these, a polycarbonate film or a cyclic olefin resin film, a (meth) acrylic resin film, or a cellulose resin film is preferably a uniaxially stretched film or a biaxially stretched film. . In this specification, a zero retardation film may be used as the protective film. In addition, a film such as a uniaxial retardation film, a wide viewing angle retardation film, a low photoelastic modulus retardation film, or the like may be used as the retardation film.

The zero retardation film refers to a film in which the in-plane retardation value R _e and the thickness direction retardation value R _th are both -15 to 15 nm. This retardation film can be used for a liquid crystal display device in the IPS mode. The in-plane retardation value R _e and the thickness direction retardation value R _th are preferably both -10 to 10 nm, and more preferably -5 to 5 nm. Referred to herein retardation value R _e plane retardation and the thickness direction R _th value of the mean wavelength of 590nm.

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

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

The zero retardation film can be made of, for example, a polyolefin resin such as a cellulose resin, a chain polyolefin resin, and a cyclic polyolefin resin, a polyethylene terephthalate resin, or a (meth) acrylic resin. Of resin film. In particular, since the control of the retardation value is easy and easy to obtain, it is preferable to use a cellulose resin, a polyolefin resin, or a (meth) acrylic resin.

In addition, a film exhibiting optical anisotropy by application and alignment of a liquid crystal compound, and a film exhibiting optical anisotropy by application of an inorganic layered compound can also be used as a retardation film. Such retardation films include those known as temperature-compensated retardation films, films that are obliquely aligned by rod-shaped liquid crystals sold by JX Nippon Nissei Energy Co., Ltd. under the trade name "NH Film", and Fujifilm negatives (shares ) Films with oblique alignment of the disc-shaped liquid crystals sold under the trade name of "WV Film", and fully biaxially oriented films sold by Sumitomo Chemical Co., Ltd. under the trade name of "VAC Film" are similarly manufactured by Sumitomo Chemical ( Stock) A biaxially oriented film sold under the trade name "new VAC Film". The resin film laminated on at least one side of the retardation film may be, for example, the aforementioned protective film.

[3] Optical laminated body

The present invention is an optical laminate including an optical film including the aforementioned adhesive layer. The optical laminated body is preferably a substrate containing the optical film with an adhesive layer and an adhesive layer side laminated on the optical film with the adhesive layer.

The substrate is a conventional substrate, and examples thereof include glass substrates, plastic films, organic conductive films, metal layers, and overcoat resin layers. Since the adhesive layer of the present invention is formed of the aforementioned adhesive composition, even if a transparent electrode layer such as ITO or a metal layer such as a metal mesh (metal wiring layer) is used as a substrate, it is subjected to severe and durable conditions. It also has excellent durability.

4 to 8 are schematic cross-sectional views showing examples of the optical multilayer body of the present invention.

The optical laminated body 5 shown in FIG. 4 is an electrode layer 30 laminated on the substrate 40, and is laminated on the surface of the adhesive layer of the optical film 1a with the adhesive layer (or the polarizing plate 10a with the adhesive layer). Optical laminates. The aforementioned optical film 1a with an adhesive layer is an area-layer adhesive layer 20 on the polarizer 2 side of the aforementioned polarizing plate 10a.

The optical laminated body 6 shown in FIG. 5 is an electrode layer 30 laminated on the substrate 40 and laminated on the adhesive layer of the optical film 1b with an adhesive layer (or the polarizing plate 10b with an adhesive layer). Optical multilayers. The optical film 1b with an adhesive layer is an optical film with an adhesive layer 20 in an area on the second resin film 4 side of the polarizing plate 10b.

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

A method of forming the electrode layer 30 on the substrate 40 may be, for example, a sputtering method. The substrate 40 may be a transparent substrate constituting a liquid crystal cell included in the touch input element, and is preferably a glass substrate. The glass substrate may be made of soda-lime glass, low-alkali glass, or alkali-free glass. The electrode layer 30 may be formed on the entire surface of the substrate 40 or may be formed on a part thereof.

The electrode layer 30 may be, for example, a transparent electrode layer or a metal layer.

Examples of the transparent electrode layer include layers made of tin oxide, indium oxide, zinc oxide, potassium oxide, aluminum oxide, and mixtures thereof. From the viewpoints of conductivity and visible light transmittance, ITO is preferred.

Examples of the metal layer include a layer containing at least one 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. Among these, from the viewpoint of conductivity, a metal layer containing at least one metal element selected from aluminum, copper, silver, and gold is preferable, and a metal layer containing at least one metal element selected from aluminum, copper, and silver is more preferable. Metal layer.

The metal layer may be a metal mesh in which a metal wiring layer of fine wires is arranged on a substrate, or a layer in which metal nano particles and metal nano wires are added to an adhesive.

The method for preparing the electrode layer 30 is not particularly limited, and may be formed by a vacuum evaporation method, a sputtering method, an ion deposition method, an inkjet printing method, or a gravure printing method.

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

The thickness of the electrode layer 30 is not particularly limited, but is usually 3 μm or less, preferably 1 μm or less, more preferably 0.8 μm or less, and usually 0.01 μm or more. When the electrode layer 30 is a metal wiring layer (such as 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 laminated body 7 shown in FIG. 6 is an optical laminated body in which the aforementioned adhesive layer 20 of the optical film 1 with an adhesive layer is laminated on the substrate 40.

The optical laminated body 8 shown in FIG. 7 is attached to the surface of the electrode layer 30 (the surface opposite to the substrate 40) laminated on the substrate 40, and the laminated resin layer 50 is laminated on the aforementioned adhesive Layer of the optical film 1 on the side of the adhesive layer 20 of the optical laminate. Examples of the resin forming the resin layer 50 include the resins constituting the first or second resin film exemplified above.

The optical laminated body 9 shown in FIG. 8 is attached to the substrate 40, and a plurality of electrode layers 30 are laminated at predetermined intervals in the length and width directions. Between the plurality of electrode layers 30 (or gaps) and the electrode layers 30 The resin layer 50 is formed (or laminated) on the surface (surface on the side opposite to the substrate 40), except that it is the same as the optical laminated body 7. When the optical laminated body 9 is in the form (the electrode layer 30 has been patterned into a predetermined shape), the metal layer 30 may also be a metal wiring layer of a touch input element included in a touch input type liquid crystal display device ( (Ie electrode layer).

In the optical laminated body 9, the plurality of electrode layers 30 may be entirely or partially in contact with the adhesive layer 20 or may not be in contact. The electrode layer 30 may be a continuous film containing the above-mentioned metal or alloy. The resin layer 50 may be omitted.

After the optical film (1, 1a, 1b) with the adhesive layer is attached to the substrate 40 (glass substrate, transparent substrate, etc.) or the electrode layer 30 to make an optical laminate, if there is any problem, the The optical film of the adhesive layer is peeled from the substrate 40 or the electrode layer 30, and another optical film with the adhesive layer is reattached to the substrate 40 or the electrode layer 30, which is a so-called reprocessing operation. The optical film 1 with an adhesive layer of the present invention is less likely to generate fogging or adhesive residue on the surface of a glass substrate or an electrode layer (such as a transparent electrode such as ITO) after peeling, and has excellent reworkability.

[4] Liquid crystal display device

The adhesive layer, the optical film with the adhesive layer, and the optical laminate of the present invention can be used in a liquid crystal display device, and the liquid crystal display device has good durability.

The liquid crystal display device may also be a touch input type liquid crystal display device having a touch panel function. The touch input type liquid crystal display device includes a touch input element including a liquid crystal cell, and a back plate. The structure of the touch panel can be a well-known method (for example, out cell type, on cell type, in cell type, etc.), and the operation mode of the touch panel can be a well-known method, such as a resistive film method and a capacitive method ( Surface capacitive type, projected capacitive type), etc. The optical film with an adhesive layer of the present invention may be arranged on the visual recognition side of a touch input element (liquid crystal cell), may be arranged on the back plate side, or may be arranged on both sides. The driving method of the liquid crystal cell may be any of conventionally known methods such as a TN method, a VA method, an IPS method, a multi-domain configuration method, and an OCB method. In the liquid crystal display device, the substrate 40 having an optical laminate may be a substrate (typically, a glass substrate) included in the liquid crystal cell.

[5] Siloxane compound for adhesive (A)

The present invention also includes a silicone compound (A) for an adhesive. The aforementioned siloxane compound (A) for the adhesive is the same as the above siloxane compound (A), the ratio of the alkoxy group of the hydrolyzed condensate (a), the weight average molecular weight of the hydrolyzed condensate (a), and The preferred ranges are also the same. The adhesive layer using the siloxane compound (A) for an adhesive is not particularly limited, and preferably includes, for example, an adhesive layer composed of the adhesive composition described in the above [1].

    [Example]    

Hereinafter, examples and comparative examples will be disclosed to explain the present invention more specifically, but the present invention is not limited to these examples. In the following, the usage amount, content, and% are indicated. All are based on quality unless otherwise specified.

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

In a reaction vessel including a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, a solution obtained by mixing a monomer having a composition shown in Table 1 (the numerical value in Table 1 is mass parts) with 81.8 parts of ethyl acetate was charged. After replacing the air in the reaction vessel with nitrogen, the internal temperature was adjusted to 60 ° C. Then, a solution in which 0.12 parts of azobisisobutyronitrile was 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, and the addition rate was 17.3 parts / Hr, and the concentration of the polymerization degree was approximately 35%, and ethyl acetate was continuously added to the reaction vessel. . Twelve hours after the start of the addition of ethyl acetate, the internal temperature was maintained at 54 to 56 ° C, and then, ethyl acetate was added so that the concentration of the polymer was adjusted to 20% to obtain a (meth) acrylate resin. (B-1) in ethyl acetate. The weight average molecular weight Mw of the obtained (meth) acrylate 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 Example 2: Production of (meth) acrylic resin (B-2) for adhesive>

An ethyl acetate solution (resin concentration: 20%) of a (meth) acrylic resin (B-2) was prepared in the same manner as in Production Example 1 except that the composition of the monomer was as shown in Table 1. The weight average molecular weight Mw of the obtained (meth) acrylate resin (B-2) was 1.42 million, and Mw / Mn was 5.2.

In the above manufacturing examples, the weight average molecular weight Mw and the number average molecular weight Mn were measured in the following manner. In a GPC apparatus, four "TSKgel XL" manufactured by Tosoh Corporation and "Shodex GPC manufactured by Showa Denko Corporation" were used. A total of 5 KF-802 "in a row are arranged as a column, and tetrahydrofuran is used as the eluent. The sample concentration is 5 mg / mL, the sample introduction volume is 100 μL, the temperature is 40 ° C, and the flow rate is 1 mL / min. It is measured by standard styrene conversion. The conditions for obtaining the GPC flow curve are the same as described above.

The glass transition temperature Tg was measured using a differential scanning thermal analysis (DSC) "EXSTAR DSC6000" manufactured by SII Nanotechnology (Stock) under a nitrogen environment at a measurement temperature range of -80 to 50 ° C and a heating rate of 10 ° C / min. Determination.

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

The abbreviations in the "monomer composition" column of Table 1 refer to the following monomers.

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

MA: methyl acrylate (glass transition temperature of homopolymer: 10 ° C)

HEA: 2-hydroxyethyl acrylate

5HPA: 5-hydroxypentyl acrylate

PEA: phenoxyethyl acrylate

AA: Acrylic

<Production Example 3: Production Method of Siloxane Compound A-1>

A reaction vessel including a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer was charged with 326 parts of 1,6-bistrimethoxysilylhexane and 97.2 parts of methanol. After the air in the reaction vessel was replaced with nitrogen, the internal temperature was adjusted to 25 ° C. Thereafter, a mixed solution of 0.6 parts of a 1-equivalent hydrochloric acid aqueous solution, 10.2 parts of water, and 10.2 parts of methanol was added to the reaction vessel. The resulting mixture was stirred for 1 hour and then refluxed for 2 hours. After cooling, 1.0 part of a 10% sodium acetate methanol solution was added to the obtained mixture, and refluxed for 2 hours. The solvent was distilled off from the obtained mixture to obtain a siloxane compound (A-1).

The weight average molecular weight of the obtained siloxane compound (A-1) was 1,300. In addition, it was confirmed by ¹ H-NMR that the amount of water added was consistent with that of 20% of the alkoxy group having been hydrolyzed. That is, the content of the alkoxy group contained in the siloxane compound (A-1) is 100 mol% relative to the total amount of the alkoxy groups contained in 1,6-bistrimethoxysilylhexane. 80 mol%.

<Manufacturing Example 4: Method for Producing Siloxane Compound A-2>

A reaction vessel provided with a cooling tube, a thermometer, and a stirrer was charged with 326 parts of 1,6-bistrimethoxysilylhexane and 97.2 parts of methanol. After the air in the reaction vessel was replaced with nitrogen, the internal temperature was adjusted to 25 ° C. After that, a mixed solution of 0.6 parts of a 1N aqueous hydrochloric acid solution, 7.5 parts of water, and 10.2 parts of methanol was added to the reaction vessel. The resulting mixture was stirred for 1 hour and then refluxed for 2 hours. After cooling, 1.0 part of a 10% sodium acetate methanol solution was added to the obtained mixture, and refluxed for 2 hours. The solvent was distilled off from the obtained mixture to obtain a siloxane compound (A-2).

The weight average molecular weight of the obtained siloxane compound (A-2) was 920. In addition, it was confirmed by ¹ H-NMR that 15% of the alkoxy group was hydrolyzed in accordance with the amount of water added. That is, the content of the alkoxy group contained in the siloxane compound (A-2) is 100 mol% relative to the total amount of the alkoxy groups contained in 1,6-bistrimethoxysilylhexane, which is 85 mole%.

<Examples 1 to 9 and Comparative Examples 1 to 3>

(1) Preparation of adhesive composition

In the ethyl acetate solution (resin concentration: 20%) of the (meth) acrylic acid ester resin obtained in the above production example, silicon was mixed in an amount (parts by mass) shown in Table 2 with respect to 100 parts of the solid content of the solution. The oxyalkane compound (A), the crosslinked fluorene (C) and the antistatic agent (E) in Examples 4, 7 and 8, and then ethyl acetate was added so that the solid content concentration was 14% to obtain an adhesive.组合 物。 Composition. The blending amount of each blending ingredient shown in Table 2 is the mass parts of the active ingredient contained in the product when it contains a solvent or the like.

The detailed description of each compounding ingredient shown by the abbreviation in Table 2 is as follows.

(Siloxanes (A))

A-1: Siloxane compound (A) obtained in Production Example 3 (hydrolysis condensate of 1,6-bis (trimethoxysilyl) hexane, hydrolysis rate 20%)

A-2: Siloxane compound (A) obtained in Production Example 4 (hydrolyzed condensate of 1,6-bis (trimethoxysilyl) hexane, hydrolysis rate 15%)

A-3: Made by Shin-Etsu Chemical Industry Co., Ltd., trade name "X-12-967C" (trimethoxysilylpropylsuccinic anhydride)

A-4: 1,3-bis [3- (trimethoxysilyl) propyl] urea

A-5: KBM403 (3-glycidoxypropyltrimethoxysilane)

(Crosslinking agent (C))

C-1: Made by Tosoh Corporation under the trade name "CoronateL" (ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid content concentration 75%))

(Antistatic agent (E))

E-1: N-decylpyridine bis (fluorosulfonyl) fluorenimine.

(2) Production of adhesive layer

Using a spreader, each adhesive composition prepared in (1) above was applied to a release film having a thickness of 20 μm to a release film made of a polyethylene terephthalate film subjected to a release treatment [made by Obtained from Lintec Co., Ltd. under the trade name "PLR-382051"], and dried at 100 ° C for 1 minute to prepare an adhesive layer (adhesive sheet).

(3) Production of optical film (P-1) with adhesive layer

A polyvinyl alcohol film with an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol%, and a thickness of 60 μm [(Kuraray) 's trade name "Kuraray vinylon (KURALON) VF-PE # 6000"] manufactured by Kuraray] was dipped in a pure resin at 37 ° C. After 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. Then, it was immersed in an aqueous solution containing potassium iodide and boric acid (potassium iodide / boric acid / water (mass ratio) = 12 / 3.6 / 100) at 56.5 ° C. The film was washed with pure water at 10 ° C, and then dried at 85 ° C to obtain a polarizer having a thickness of about 23 μm with iodine adsorbed and aligned on polyvinyl alcohol. Stretching is mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio is 5.3 times.

On one side of the obtained polarizer, a transparent protective film composed of a triethyl cellulose film with a thickness of 25 μm was passed through an adhesive composed of an aqueous solution of a polyvinyl alcohol resin [a product made by Konica Minolta Opto (stock)] "KCUA"]. Next, a zero phase consisting of a cyclic polyolefin resin having a thickness of 23 μm was adhered to the surface of the above-mentioned polarizer on the side opposite to the triethyl cellulose film through an adhesive composed of an aqueous solution of a polyvinyl alcohol resin. The differential film [trade name "ZEONOR" made by ZEON (Japan)] was made into a polarizing plate. Next, a corona discharge treatment is performed on the surface of the zero-phase-difference film on the side opposite to the surface that is in contact with the polarizer, and then it is bonded to the adhesive produced by (2) above with a bonding machine. After the surface of the adhesive layer opposite to the release film (adhesive layer) was cured at a temperature of 23 ° C. and a relative humidity of 65% for 7 days, an optical film (P-1) with an adhesive layer was prepared.

(4) Durability evaluation of an optical film with an adhesive layer

The optical film (P-1) with an adhesive layer prepared in the above (3) was cut into a size of 300 mm × 220 mm so that the direction of the stretching axis of the polarizing plate was a long side, and the release film was peeled to make The exposed adhesive layer is bonded to a glass substrate or a glass substrate with ITO (tin-doped indium oxide). The obtained test piece attached to the glass substrate (the optical film with an adhesive layer attached to the glass substrate) was pressed in an oven at a temperature of 50 ° C. and a pressure of 5 kg / cm ² (490.3 kPa) for 20 minutes. The glass substrate is an alkali-free glass product "Eagle XG" manufactured by Corning. In addition, the glass substrate with ITO is a non-alkali glass [trade name "Eagle XG"] manufactured by Corning Corporation, and a 30 nm ITO layer is formed by evaporation.

The obtained optical laminate was subjected to the following durability tests.

[Durability test]

‧Heat resistance test (glass substrate) for 1000 hours under 95 ° C dry conditions

‧Heat resistance test for 1000 hours under dry conditions at 95 ℃ (glass substrate with ITO)

‧Damp heat resistance test (glass substrate) for 1000 hours in an environment with a temperature of 60 ° C and a relative humidity of 90%

‧The operation of holding for 30 minutes in a dry condition at a temperature of 85 ° C and then for 30 minutes in a dry condition of -40 ° C was performed for one cycle, and the heat shock (HS) test (glass substrate) for 1,000 cycles was repeated.

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

5: No appearance change such as floating, peeling, foaming

4: There are almost no appearance changes such as floating, peeling, and foaming

3: A slight change in appearance such as floating, peeling, foaming can be confirmed

2: Significant changes in appearance such as floating, peeling, and foaming

1: Significantly confirm appearance changes such as floating, peeling, and foaming

When it is 3 or more, the durability is good.

(5) Evaluation of adhesion of optical film with adhesive layer

The optical film (P-1) with an adhesive layer prepared in the above (3) was cut into a test piece having a size of 25 mm × 150 mm. The release film was peeled from the test piece, and the adhesive layer was attached to the glass substrate. The obtained test piece attached to the glass substrate (the optical film with an adhesive layer attached to the glass substrate) was pressed in an oven at a temperature of 50 ° C. and a pressure of 5 kg / cm ² (490.3 kPa) for 20 minutes. After being stored in an environment at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours, the optical film and the adhesive layer were peeled together from the test piece in a direction of 180 ° at a speed of 300 mm / min. The average peeling force at the time of peeling is shown in Table 3 as an adhesive force.

When the adhesion is 6N or less, the reworkability is excellent, and when it is 0.5N or more, peeling does not easily occur when an impact is received from the end of the polarizing plate.

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

After the obtained release film of the polarizing film with an adhesive layer was peeled off, the surface resistance value was measured with a surface resistivity measuring device ["Hiresta-up MCP-HT450" (trade name) manufactured by Mitsubishi Chemical Corporation). The measurement was performed under measurement conditions of an applied voltage of 250 V and an applied time of 10 seconds. When the surface resistance value is 1.0 g × 10 ¹² Ω / □ or less, good antistatic properties can be obtained.

[Gel fraction of adhesive sheet]

The method for evaluating the gel fraction of the adhesive sheet of the present invention will be described below. The larger the gel fraction, the more crosslinking reactions take place in the adhesive, which can be used as a measure of the crosslinking density. The gel fraction is a value measured based on the following (a) to (d).

(a) A metal mesh (its mass is Wm) composed of an adhesive sheet with an area of 8 cm × about 8 cm and SUS304 about 10 cm × about 10 cm.

(b) Weigh the patch obtained in (a) above, take the mass as Ws, then fold it 4 times to wrap the adhesive sheet and fix it with a stapler, and then weigh it, and let the mass be Wb.

(c) Put the net fixed in the binder (b) above into a glass container, add 60 mL of ethyl acetate for impregnation, and store the glass container at room temperature for 3 days.

(d) Take out the net from the glass container, and measure it after drying at 120 ° C for 24 hours. The mass is taken as Wa, and the gel fraction is calculated according to the following formula.

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

The optical films with adhesive layers obtained in Examples 1 to 9 exhibited good durability even under severe durability conditions. Shows good durability even when used on ITO substrates. In addition, it also has good reworkability and can balance durability and reworkability.

Claims (15)

An adhesive composition containing a siloxane compound (A), wherein the siloxane compound (A) is a hydrolysis-condensation condensate (a) of a hydrolysis-condensable silane compound represented by the following formula (a1), In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH ₂ -constituting the aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group may be -O- or -CO- substituted, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms Alkyl or alkoxy having 1 to 5 carbons.     The pressure-sensitive adhesive composition according to item 1 of the scope of patent application, wherein the content of the alkoxy group contained in the siloxane compound (A) is higher than that of the alkoxy group contained in the hydrolyzable and condensable silane compound (a1). The total amount is 100 mol%, ranging from 60 to 95 mol%.         The adhesive composition according to item 1 or 2 of the scope of patent application, wherein the weight average molecular weight of the siloxane compound (A) is 600 to 4000 in terms of styrene.         The adhesive composition according to any one of claims 1 to 3 of the scope of patent application, further comprising a (meth) acrylic resin (B) and a crosslinking agent (C).         The pressure-sensitive adhesive composition according to item 4 of the scope of patent application, wherein the proportion of the siloxane compound (A) is 0.01 to 10 parts by mass based on 100 parts by mass of the (meth) acrylic resin (B).         The adhesive composition according to item 4 or 5 of the scope of application for a patent, wherein the (meth) acrylic resin (B) contains an alkyl acrylate (b1) derived from a monomer having a glass transition temperature of less than 0 ° C ) And the unit derived from an alkyl acrylate (b2) having a glass transition temperature of 0 ° C or higher derived from a monomer.         The adhesive composition according to any one of claims 4 to 6 in the scope of the patent application, wherein the (meth) acrylic resin (B) contains a carboxyl group-containing (meth) acrylate constituting unit The ratio is 1.0 mass part or less with respect to 100 mass parts of the total constitutional unit constituting the (meth) acrylic resin (B).         The pressure-sensitive adhesive composition according to any one of claims 4 to 7, wherein the weight average molecular weight of the (meth) acrylic resin (B) is 1 to 2.5 million in terms of polystyrene.         The pressure-sensitive adhesive composition according to any one of claims 4 to 8, in which the crosslinking agent (C) is an isocyanate-based compound.         The pressure-sensitive adhesive composition according to any one of claims 4 to 9 in the patent application scope, wherein the proportion of the cross-linking agent (C) is 0.01 with respect to 100 parts by mass of the (meth) acrylic resin (B). To 10 parts by mass.         An adhesive layer is composed of the adhesive composition described in any one of claims 1 to 10 of the scope of patent application.         An optical film with an adhesive layer is formed by laminating the adhesive described in item 11 of the scope of the patent application on at least one side of the optical film.         For example, the optical film with an adhesive layer described in item 12 of the scope of the patent application, wherein the adhesive layer on the surface of the optical film with the adhesive layer that is not bonded to the optical film is bonded to a glass substrate at a temperature Adhesion after storage for 24 hours at 23 ° C and 50% relative humidity. The peeling speed is 300 mm / min., 0.5 to 10 N / 25 mm.         An optical multilayer body is an optical film including an adhesive layer as described in item 12 or 13 of the scope of patent application.     A siloxane compound (A) for an adhesive is a hydrolysis-condensation condensate (a) of a hydrolytic-condensable silane compound represented by the following formula (a1), In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH ₂ -which may constitute the aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group may be -O- Or -CO- substituted, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms or Alkoxy having 1 to 5 carbons.