KR102515307B1 - adhesive composition - Google Patents

Abstract

In the present invention, the following formula (a1) (wherein B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, -CH constituting the alkanediyl group and the alicyclic hydrocarbon group) _2- may be substituted with -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 have 1 carbon atom A pressure-sensitive adhesive composition containing a siloxane compound (A) which is a hydrolysis condensation product (a) of a hydrolytic condensation silane compound represented by an alkyl group of -5 or an alkoxy group of 1 to 5 carbon atoms).

Description

adhesive composition

This patent application claims priority under the Paris Convention regarding Japanese Patent Application No. 2017-103018 (filing date: May 24, 2017), and the entirety thereof is incorporated herein by reference here.

The present invention relates to a pressure-sensitive adhesive composition useful as an optical member used in a liquid crystal display device, etc., a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition, an optical film with a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive layer, an optical laminate comprising the optical film with a pressure-sensitive adhesive layer, and siloxane compounds for pressure-sensitive adhesives.

An optical film typified by a polarizing plate formed by laminating and bonding a transparent resin film on one side or both sides of a polarizer is widely used as an optical member constituting an image display device such as a liquid crystal display device. An optical film such as a polarizing plate is often used by being bonded to another member (for example, a liquid crystal cell in a liquid crystal display device) through an adhesive layer (see Patent Document 1). For this reason, as an optical film, the optical film with an adhesive layer in which the adhesive layer was previously formed in the one surface is known.

Patent Document 1: Japanese Unexamined Patent Publication No. 2010-229321

In recent years, liquid crystal display devices have been developed for mobile device applications represented by smart phones and tablet terminals, and in-vehicle device applications represented by car navigation systems. In such applications, since there is a possibility of being exposed to a harsher environment than conventional indoor TV applications, improving the durability of the device has become a challenge.

Durability is similarly requested|required also with the optical film with an adhesive layer which comprises a liquid crystal display device etc. That is, the pressure-sensitive adhesive layer inserted into the liquid crystal display device or the like may be placed in a high-temperature or high-temperature, high-humidity environment or in an environment in which high and low temperatures are repeated. It is required to be able to suppress problems such as lifting and peeling at the interface between the optical member and the optical member to be bonded thereto, and foaming of the pressure-sensitive adhesive layer, and it is also required that the optical properties are not deteriorated. In particular, in a touch panel or the like in which an optical film with an adhesive layer is applied (bonded or laminated) to a transparent electrode such as ITO (tin-doped indium oxide), it is difficult to express high durability under the severe durability conditions as described above. Even in this case, high durability performance is required.

Therefore, an object of the present invention is to provide a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer exhibiting good durability under severe durability conditions even when applied to a transparent electrode layer such as ITO, a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition, and a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive layer It is providing the optical laminated body containing an optical film with an adhesive, the said optical film with an adhesive layer, and the siloxane compound for adhesives.

The present inventors completed the present invention as a result of intensive studies in order to solve the above problems. That is, the following are included in this invention.

[1] As an adhesive composition containing a siloxane compound (A),

The siloxane compound (A) has the following formula (a1)

(Wherein, 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 alkanediyl group and the alicyclic hydrocarbon group is -O- or - may be substituted with 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 an alkyl group having 1 to 5 carbon atoms or a carbon atom 1 to 5 carbon atoms represents an alkoxy group of 5)

An adhesive composition that is a hydrolysis condensation product (a) of a hydrolysis condensation silane compound represented by

[2] The content of the alkoxy groups contained in the siloxane compound (A) is described in [1], which is 60 to 95 mol% with respect to 100 mol% of the total amount of alkoxy groups contained in the hydrolytic condensation silane compound (a1). adhesive composition.

[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the weight average molecular weight of the siloxane compound (A) is 800 to 4000 in terms of polystyrene.

[4] The pressure-sensitive 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 ratio of the siloxane compound (A) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (B).

[6] The (meth)acrylic resin (B) includes structural units derived from an alkyl acrylate (b1) having a homopolymer glass transition temperature of less than 0°C, and an alkyl acrylate (b2) having a homopolymer glass transition temperature of 0°C or higher. ) The pressure-sensitive adhesive composition according to [4] or [5], comprising a structural unit derived from.

[7] The ratio of the constituent units derived from the carboxyl group-containing (meth)acrylate contained in the (meth)acrylic resin (B) is 1.0 parts by mass relative to 100 parts by mass of all constituent units constituting the (meth)acrylic resin (B). The pressure-sensitive adhesive composition according to any one of [4] to [6], which is below parts.

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

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

[10] The adhesive composition according to any one of [4] to [9], wherein the ratio of the crosslinking agent (C) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (B).

[11] A pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition according to any one of [1] to [10].

[12] An optical film with a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer according to [11] is laminated on at least one surface of the optical film.

[13] The adhesive strength after bonding the pressure-sensitive adhesive layer on the side not bonded to the optical film of the optical film with the pressure-sensitive adhesive layer to the glass substrate and storing for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 50% is a peel rate of 300 The optical film with a pressure-sensitive adhesive layer described in [12], which is 0.5 to 10 N/25 mm at mm/min.

[14] An optical laminate comprising the optical film with a pressure-sensitive adhesive layer according to [12] or [13].

[15] The following formula (a1)

(Wherein, 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 alkanediyl group and the alicyclic hydrocarbon group is -O- or - may be substituted with 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 an alkyl group having 1 to 5 carbon atoms or a carbon atom 1 to 5 carbon atoms represents an alkoxy group of 5)

A siloxane compound (A) for an adhesive which is a hydrolysis condensation product (a) of a hydrolysis condensation silane compound represented by

Even when the pressure-sensitive adhesive composition of the present invention is applied to a transparent electrode layer such as ITO, it can form a pressure-sensitive adhesive layer exhibiting good durability under severe durability conditions.

1 is a schematic sectional view showing an example of an optical film with a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition according to the present invention.
2 is a schematic cross-sectional view showing an example of a layer structure of a polarizing plate.
3 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate.
Fig. 4 is a schematic cross-sectional view showing an example of an optical laminate comprising an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention.
5 is a schematic cross-sectional view showing another example of an optical laminate comprising an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention.
6 is a schematic cross-sectional view showing still another example of an optical laminate comprising an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention.
7 is a schematic cross-sectional view showing another example of an optical laminate comprising an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention.
8 is a schematic cross-sectional view showing another separate example of an optical laminate comprising an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present invention.

[1] Adhesive composition

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

[1-1] Siloxane compound (A)

The siloxane compound (A) has the following formula (a1)

(Wherein, 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 alkanediyl group and the alicyclic hydrocarbon group is -O- or - It may be substituted with CO-.

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)

It is the hydrolytic condensation product (a) of the hydrolytic condensation silane compound represented by

In formula (a1), B is an alkanediyl group having 1 to 20 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, a heptamethylene group, and an octamethylene group; Cyclobutylene group (eg 1,2-cyclobutylene group), cyclopentylene group (eg 1,2-cyclopentylene group), cyclohexylene group (eg 1,2-cyclohexylene group), cyclooctylene group (eg 1 divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, such as a 2-cyclooctylene group); Or a group in which -CH ₂ - constituting these alkanediyl groups and the alicyclic hydrocarbon group is substituted with -O- or -CO-. Preferred B is an alkanediyl group having 1 to 10 carbon atoms.

R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 5 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl and pentyl ; or an alkoxy group having 1 to 5 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an i-propoxy group, a butoxy group, a s-butoxy group, and a t-butoxy group. It is preferable that R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent 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 include the same alkyl groups 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, 1,2-bis(triethoxysilyl)ethane, and 1,3-bis (trimethoxysilyl)propane, 1,3-bis(triethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,4-bis(triethoxysilyl)butane, 1,5 -Bis (trimethoxysilyl) pentane, 1,5-bis (triethoxysilyl) pentane, 1,6-bis (trimethoxysilyl) hexane, 1,6-bis (triethoxysilyl) hexane, 1 ,6-bis(tripropoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane, 1,8-bis(triethoxysilyl)octane, 1,8-bis(tripropoxysilyl)octane bis(tri C _1-5 alkoxysilyl) C _1-10 alkanes such as; Bis (dimethoxymethylsilyl) methane, 1,2-bis (dimethoxymethylsilyl) ethane, 1,2-bis (dimethoxyethylsilyl) ethane, 1,4-bis (dimethoxymethylsilyl) butane, 1, 4-bis(dimethoxyethylsilyl)butane, 1,6-bis(dimethoxymethylsilyl)hexane, 1,6-bis(dimethoxyethylsilyl)hexane, 1,8-bis(dimethoxymethylsilyl)octane, bis(diC _1-5 alkoxy C _1-5 alkylsilyl) C _1-10 alkanes such as 1,8-bis(dimethoxyethylsilyl)octane _; Bis (mono C 1-5 alkoxydi C _1-5 alkylsilyl) C _1-10 alkanes such as 1,6-bis (methoxydimethylsilyl) hexane, 1,8-bis ( _{methoxydimethylsilyl} ) octane, etc. can be heard Among these, 1,2-bis (trimethoxysilyl) ethane, 1,3-bis (trimethoxysilyl) propane, 1,4-bis (trimethoxysilyl) butane, 1,5-bis (trimethoxysilyl) Bis (tri C _1-3 alkoxysilyl) C _1-10 alkanes such as oxysilyl) pentane, 1,6-bis (trimethoxysilyl) hexane, and 1,8-bis (trimethoxysilyl) octane are preferred. In particular, 1,6-bis(trimethoxysilyl)hexane and 1,8-bis(trimethoxysilyl)octane are preferable.

The hydrolytic condensation product (a) of the hydrolytic condensation silane compound represented by the formula (a1) (hereinafter sometimes referred to as the hydrolysis condensable silane compound (a1)) is a hydrolytic condensation silane compound (a1 ) means a condensate obtained by hydrolysis and condensation of an alkoxy group, which is a hydrolysable group in , such as a dimer or an oligomer. In addition, even if the hydrolysis-condensation product (a) is a hydrolysis-condensation product (sometimes referred to as a partial hydrolysis-condensation product) in which the alkoxy group of the hydrolysis-condensable silane compound (a1) is partially hydrolyzed and condensed, A condensate in which all of the alkoxy groups are hydrolyzed and condensed may be used. In addition, even if the alkoxy group of the hydrolyzable silane compound (a1) is hydrolyzed to a hydroxyl group and the resulting hydroxyl group is then condensed, a part of the hydroxyl group remains in the hydrolysis-condensation product (a) without being condensed. good night.

In the hydrolytic condensation product (a), a structural unit derived from the hydrolysis condensable silane compound (a1) forms a Si-O-Si bond by partial or total, preferably partial hydrolysis and condensation of an alkoxy group. has a repeating structure. The hydrolysis condensation product (a) may be linear or branched.

Since the pressure-sensitive adhesive composition of the present invention contains the siloxane compound (A), the durability of the pressure-sensitive adhesive layer can be improved even when, for example, a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition is applied (bonded or laminated) to an electrode layer, and can be used in a high-temperature environment. Peeling (or lifting) and foaming of the island interface can be effectively suppressed. Moreover, the said adhesive composition also has favorable reworkability (peelability). For this reason, the adhesive composition of this invention can make favorable durability and reworkability make compatible.

In this specification, durability refers to a property capable of suppressing lifting or peeling at the interface between an adhesive layer and an optical member adjacent thereto under, for example, a high-temperature environment, a high-temperature, high-humidity environment, or an environment in which high and low temperatures are repeated. (sometimes referred to as peeling property), and characteristics capable of suppressing problems such as foaming of the pressure-sensitive adhesive layer (sometimes referred to as foaming resistance). In addition, in this specification, cohesive failure resistance refers to a characteristic capable of suppressing cohesive failure (or tearing) of the pressure-sensitive adhesive layer.

The hydrolysis-condensation product (a) is preferably a partial hydrolysis-condensation product of the hydrolysis-condensation silane compound (a1). The content of alkoxy groups contained in the siloxane compound (A) is preferably 60 mol% or more, more preferably 65 mol%, relative to 100 mol% of the total amount of alkoxy groups contained in the hydrolytic condensation silane compound (a1). % or more, more preferably 70 mol% or more, preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 88 mol% or less, any combination of the lower limit and the upper limit thereof It may be, for example, 60 to 95 mol%, preferably 65 to 90 mol%, and more preferably 70 to 88 mol%. When the content of the alkoxy group contained in the siloxane compound (A) is equal to or greater than the lower limit, the durability of the pressure-sensitive adhesive layer can be further improved, and when the content is equal to or less than the upper limit, the reworkability of the pressure-sensitive adhesive layer can be further improved.

Content of the alkoxy group contained in a siloxane compound (A) can be adjusted with the compounding quantity of hydrolysis water. 1 mol of alkoxy groups contained in the hydrolytic condensation silane compound (a1) are hydrolyzed with 0.5 mol of hydrolysis water. If the content of the alkoxy groups contained in the siloxane compound (A) is 60 mol% with respect to 100 mol% of the total amount of alkoxy groups contained in the hydrolysis condensable silane compound (a1), the hydrolysis condensable silane compound (a1) It becomes what hydrolyzed 40% of an alkoxy group, and the hydrolysis rate becomes 40%. If the content of the alkoxy group contained in the siloxane compound (A) is 95 mol%, it will be obtained by hydrolyzing 5 mol% of the alkoxy group of the hydrolytic condensation silane compound (a1), and the hydrolysis rate will be 5%.

The weight average molecular weight of the siloxane compound (A), in terms of polystyrene by gel permeation chromatography GPC, is preferably 600 or more, more preferably 700 or more, still more preferably 800 or more, and preferably 4000 or less, It is more preferably 3000 or less, still more preferably 2000 or less, and may be any combination of these lower and upper limits, for example, 600 to 4000, preferably 700 to 3000, and more preferably 800 to 2000. When the weight average molecular weight is within the above range, the durability and reworkability of the pressure-sensitive adhesive layer can be further improved.

The siloxane compound (A) may be a hydrolysis-condensation product (a) obtained by hydrolysis and condensation of the hydrolysis-condensation silane compound (a1) alone or two or more types. In addition, the siloxane compound (A) is a hydrolysis condensable silane compound (a1) and a hydrolysis condensable silane compound other than the hydrolysis condensable silane compound (a1) [the case of the hydrolysis condensable silane compound (a2) Existing] may be a hydrolysis condensate (a). When the hydrolyzed condensation silane compound (a2) is used in combination, the siloxane compound (A) contains the hydrolyzed silane compound (a1) in an amount of preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably It is preferable to contain 90 mol% or more, particularly preferably 95 mol% or more.

In addition to the hydrolysis-condensation product (a), the siloxane compound (A) may contain single or two or more types of non-condensed silane compounds (a1). In addition, when using together the hydrolysis-condensation silane compound (a2), the silane compound (A) may contain the non-condensation hydrolysis-condensation silane compound (a2). As long as the alkoxy group of the non-condensed hydrolysis-condensable silane compound (a1 or a2) is not condensed, it may be partially or wholly hydrolyzed (converted to a hydroxyl group).

Examples of the hydrolysis condensable silane compound (a2) other than the hydrolysis condensation property silane compound (a1) include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldimethoxysilane. Toxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, vinyltridimethoxysilane, vinyltridiethoxysilane, 3-glycidoxypropyltrimethyne Toxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidpropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacrylic Oxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3- Aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropylmethyldimethyne Toxysilane, 3-mercaptopropyl methoxysilane, etc. are mentioned.

The proportion of the siloxane compound (A) is 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 0.2% by mass, based on 100% by mass of the total amount of the pressure-sensitive adhesive composition. % by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, particularly preferably 1% by mass or less, and particularly 0.5% by mass or less, these lower limits and an upper limit may be any combination, such as 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, and particularly preferably 0.2% by mass. It may be -0.5% by mass. When the ratio of the siloxane compound (A) is within the above range, the durability and reworkability of the pressure-sensitive adhesive layer can be further improved.

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

The method for producing the siloxane compound (A) is a conventional method, for example, in the presence of a solvent, adding a catalyst (for example, an acidic catalyst, a basic catalyst, etc.) as needed, and adding a hydrolytic condensation silane compound (a1) and as needed A method of mixing and stirring the hydrolytic condensation silane compound (a2), and the like are exemplified.

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

The (meth)acrylic resin (B) contains a structural unit derived from a (meth)acrylic monomer, preferably 50% by mass or more, with respect to 100% by mass of all structural units constituting the (meth)acrylic resin (B). It is preferably a polymer or copolymer containing 70% by mass or more, more preferably 90% by mass or more. In addition, in this specification, "(meth)acryl" means acryl or methacryl, and similarly about "(meth)acrylate" or "(meth)acryloyl", respectively, acrylate or methacrylate, acryl Royle or methacryloyl.

The (meth)acrylic resin (B) is, for example, a structural unit derived from a polar functional group-containing (meth)acrylate, a structural unit derived from a (meth)acrylamide monomer, a structural unit derived from a styrene monomer, and a structural unit derived from a vinyl monomer. A structural unit, a structural unit derived from a monomer having a plurality of (meth)acryloyl groups in the molecule, a structural unit derived from an alkyl acrylate, a structural unit derived from a substituent-containing alkyl acrylate, and the like may be included. These structural units can be used individually or in combination of 2 or more types.

As the (meth)acrylate containing a polar functional group, for example, (meth)acrylate containing a hydroxyl group, (meth)acrylate containing a heterocyclic group such as an epoxy group, (meth)acrylate containing a substituted or unsubstituted amino group, and (meth)acrylate containing a carboxyl group Acrylates etc. are mentioned.

As a hydroxyl group-containing (meth)acrylate, the hydroxyl group-containing (meth)acrylate etc. which are preferably shown by the following formula (b1) or (b2) are mentioned.

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

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

In the formulas (b1) and (b2), X ¹ and X ² represent a methylene group which may have a substituent. As the substituent, for example, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkyl group (eg methyl group, ethyl group, propyl group, isopropyl group, butyl group, s-butyl group, t-butyl group, A C _1-10 alkyl group such as a pentyl group and a hexyl group, preferably a C _1-6 alkyl group, more preferably a C _1-3 alkyl group), a cycloalkyl group (eg, a cyclopentyl group, a cyclohexyl group, etc.), an aryl group [ For example, phenyl group, alkylphenyl group (tolyl group, xylyl group, etc.)], aralkyl group (eg benzyl group, etc.), alkoxy group (eg C _1-4 alkoxy group such as methoxy group, ethoxy group), polyoxyalkylene group (eg dioxyethylene group etc.), cycloalkoxy group (eg C _5-10 cycloalkyloxy group such as cyclohexyloxy group etc.), aryloxy group (eg phenoxy group etc.), aralkyloxy group (eg benzyloxy group etc.), Alkylthio groups (eg, C _1-4 alkylthio groups such as methylthio and ethylthio groups), cycloalkylthio groups (eg, cyclohexylthio groups, etc.), arylthio groups (eg, thiophenoxy groups, etc.), aral A kylthio group (eg, benzylthio group, etc.), an acyl group (eg, acetyl group, etc.), a nitro group, a cyano group, and the like are exemplified. Among these, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, and the like are preferable, and an alkyl group (eg, a methyl group, an ethyl group, etc.) is particularly preferable.

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, s-butyl, t-butyl, pentyl and hexyl. may be, preferably a methyl group or the like.

In formula (b1), n represents an integer of 1 to 4, preferably an integer of 1 to 3, more preferably 2. Further, in the formula (b2), m represents an integer of 5 or more, including, for example, an integer of 5 to 20, preferably an integer of 5 to 15, more preferably an integer of 5 to 9, still more preferably It is an integer from 5 to 7. It is preferable that m is an odd number.

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

Specific examples of the hydroxy group-containing (meth)acrylate (b2) include 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, and (meth)acrylic acid. (meth)acrylic acid 5-hydroxy C _5-12 alkyl such as 5-hydroxyoctyl and (meth)acrylic acid 5-hydroxynonyl; 6-hydroxyhexyl (meth)acrylate, 6-hydroxyheptyl (meth)acrylate, 6-hydroxyoctyl (meth)acrylate, 6-hydroxynonyl (meth)acrylate, 6-hydroxydecyl (meth)acrylate, etc. of (meth)acrylic acid 6-hydroxy C _6-13 alkyl; (meth)acrylate 7-hydroxyheptyl, (meth)acrylate 7-hydroxyoctyl, (meth)acrylate 7-hydroxynonyl, (meth)acrylate 7-hydroxydecyl, (meth)acrylate 7-hydroxyundecyl (meth)acrylic acid 7-hydroxy C _7-14 alkyl such as; (meth)acrylate 8-hydroxyoctyl, (meth)acrylate 8-hydroxynonyl, (meth)acrylate 8-hydroxydecyl, (meth)acrylate 8-hydroxyundecyl, (meth)acrylate 8-hydroxydodecyl (meth)acrylic acid 8-hydroxy C _8-15 alkyl such as Sil; (meth)acrylate 9-hydroxynonyl, (meth)acrylate 9-hydroxydecyl, (meth)acrylate 9-hydroxyundecyl, (meth)acrylate 9-hydroxydodecyl, (meth)acrylate 9-hydroxy (meth)acrylic acid 9-hydroxy C _9-16 alkyl such as tridecyl; 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl acrylic acid, 10-hydroxytetradecyl (meth)acrylate (meth)acrylic acid 10-hydroxy C _10-17 alkyl such as; (meth)acrylic acid 11-hydroxyundecyl, (meth)acrylic acid 11-hydroxydodecyl, (meth)acrylic acid 11-hydroxytridecyl, (meth)acrylic acid 11-hydroxytetradecyl, (meth)acrylic acid 11- (meth)acrylic acid 10-hydroxy C _11-18 alkyl such as hydroxypentadecyl; (meth)acrylic acid 12-hydroxy C _12-19 alkyl such as 12-hydroxydodecyl (meth)acrylate, 12-hydroxytridecyl (meth)acrylate, and 12-hydroxytetradecyl (meth)acrylate; (meth)acrylic acid 13-hydroxy C _13-20 alkyl such as 13-hydroxypentadecyl (meth)acrylate, 13-hydroxytetradecyl (meth)acrylate, and 13-hydroxypentadecyl (meth)acrylate; (meth)acrylic acid 14-hydroxy C _14-21 alkyl such as 14-hydroxytetradecyl (meth)acrylate and 14-hydroxypentadecyl (meth)acrylate; (meth)acrylic acid 15-hydroxy C _15-22 alkyl, such as 15-hydroxypentadecyl (meth)acrylate and 15-hydroxyheptadecyl (meth)acrylate; and the like. Among these, from the viewpoint of durability, (meth)acrylate 5-hydroxypentyl, (meth)acrylate 5-hydroxyhexyl, (meth)acrylate 5-hydroxyheptyl, (meth)acrylate 5-hydroxyoctyl, (meth)acrylate ) A (meth)acrylate containing a hydroxyl group in which n is 5, such as 5-hydroxynonyl acrylate, is preferred, and 5-hydroxypentyl (meth)acrylate is particularly preferred.

In a preferable aspect, the (meth)acrylic resin (B) is a structural unit derived from a hydroxyl group-containing (meth)acrylate represented by the formula (b1) and a hydroxyl group-containing (meth)acrylate represented by the formula (b2) Contains the constituent units of origin. In this aspect, since the (meth)acrylic resin (B) has hydroxyalkyl groups of different carbon chain lengths (n and m) in the side chains, peeling (or lifting) and foaming of the interface in a high-temperature environment are more effective. It becomes possible to suppress and further improve the durability of the adhesive layer formed from the adhesive composition. Moreover, even if it is a case where an adhesive composition is applied to transparent electrode layers, such as ITO, durability in a high-temperature environment can be further improved. It is presumed that this is because, when the (meth)acrylic resin (A) is contained in the pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer having a crosslinking structure and crosslinking density optimal for expression of good durability can be formed.

The ratio of the structural units derived from the hydroxy group-containing (meth)acrylate represented by the formula (b1) is preferably 1.5 to 5 parts by mass, more preferably 100 parts by mass of all the structural units constituting the (meth)acrylic resin. It is preferably 2 to 4.5 parts by mass, and the ratio of the structural unit derived from the hydroxy group-containing (meth)acrylate represented by the formula (b2) is 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 group-containing (meth)acrylate represented by the formula (b1) and the structural unit derived from the hydroxyl group-containing (meth)acrylate represented by the formula (b2) is within the above range Although not particularly limited, preferably (b1)/(b2) = 13/1 to 3/1, more preferably 11/1 to 3/1, still more preferably 9/1 to 4/1, especially 7 /1 to 5/1 may be sufficient. If it is the said range, durability of an adhesive layer can be improved more.

Examples of the heterocyclic group-containing (meth)acrylate include acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth)acrylate, and modified caprolactone. Tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran, etc. are mentioned.

Examples of the substituted or unsubstituted amino group-containing (meth)acrylate include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and dimethylaminopropyl (meth)acrylate.

Examples of the carboxyl group-containing (meth)acrylate include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and carboxyalkyl (meth)acrylates (eg, carboxyethyl (meth)acrylate, carboxypentyl (meth)) acrylate) and the like. These carboxyl group-containing (meth)acrylates can be used individually or in combination of 2 or more types. Moreover, it is preferable not to contain substantially the structural unit derived from the monomer which has an amino group from a viewpoint of preventing the fall of the peelability of the separate film which can be laminated|stacked on the adhesive layer. Substantially not included means less than 1.0 parts by mass with respect to 100 parts by mass of all structural units constituting the (meth)acrylic resin (B).

The ratio of the constituent units derived from the carboxyl group-containing (meth)acrylate is 1.0 parts by mass or less with respect to 100 parts by mass of all the constituent units constituting the (meth)acrylic resin. The upper limit of the ratio of the structural unit derived from carboxyl group-containing (meth)acrylate is preferably 0.5 part by mass, more preferably 0.3 part by mass, still more preferably 0.2 part by mass, and particularly preferably 0.15 part by mass. The lower limit of the ratio of the structural unit derived from carboxyl group-containing (meth)acrylate is preferably 0 part by mass, more preferably 0.001 part by mass, still more preferably 0.005 part by mass, particularly preferably 0.01 part by mass, particularly 0.05 part by mass. is the mass part. The ratio of the structural units derived from the carboxyl group-containing (meth)acrylate may be any combination of the upper limit and the lower limit thereof, for example, 0 to 1 part by mass, preferably 0 to 0.8 part by mass, more preferably 0.001 to 0.5. Part by mass, more preferably 0.005 to 0.3 part by mass, particularly preferably 0.01 to 0.2 part by mass, particularly 0.05 to 0.15 part by mass. Corrosiveness of transparent electrode layers, such as ITO, can be suppressed when the ratio of the structural unit derived from carboxyl group-containing (meth)acrylate is below the upper limit, and durability can be improved when it is above the lower limit.

Examples of the (meth)acrylamide monomer include N-methylolacrylamide, N-(2-hydroxyethyl)acrylamide, N-(3-hydroxypropyl)acrylamide, and N-(4-hydroxyl). Butyl)acrylamide, N-(5-hydroxypentyl)acrylamide, N-(6-hydroxyhexyl)acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropyl Acrylamide, N-(3-dimethylaminopropyl)acrylamide, N-(1,1-dimethyl-3-oxobutyl)acrylamide, N-[2-(2-oxo-1-imidazolidinyl)ethyl ] Acrylamide, 2-acryloylamino-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]acrylamide, N-[2-(1-methylpropoxy)ethyl]acrylamide, N-[ 2-(2-methylpropoxy)ethyl]acrylamide [alias: N-(2-isobutoxyethyl)acrylamide], N-(2-butoxyethyl)acrylamide, N-[2-(1,1 -dimethylethoxy) ethyl] acrylamide; and the like. The durability of the pressure-sensitive adhesive layer can be further improved by including a structural unit derived from a (meth)acrylamide-based monomer. In particular, among these, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N-(2- Methylpropoxymethyl)acrylamide and the like are preferred.

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

Examples of the styrenic monomer include styrene; Alkyl styrene, such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; Halogenated styrene, such as fluoro styrene, chloro styrene, bromo styrene, dibromo styrene, and iodo styrene; nitrostyrene; acetyl styrene; methoxy styrene; Divinylbenzene etc. are mentioned.

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

Examples of monomers having a plurality of (meth)acryloyl groups in the molecule include 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, and 1,9-nonanedioldi. (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, etc. a monomer having a (meth)acryloyl group; and monomers having three (meth)acryloyl groups in the molecule, such as trimethylolpropane tri(meth)acrylate.

As an alkyl acrylate, the alkyl acrylate (b3) whose glass transition temperature (Tg) of a homopolymer is less than 0 degreeC, the alkyl acrylate (b4) whose Tg of a homopolymer is 0 degreeC or more, etc. are mentioned, for example.

Examples of the alkyl acrylate (b3) having a homopolymer glass transition temperature (Tg) of less than 0°C include ethyl acrylate, n- and i-propyl acrylate, n- and i-butyl acrylate, and n-pentyl acrylate. , n- and i-hexyl acrylate, n-heptyl acrylate, n- and i-octyl acrylate, 2-ethylhexyl acrylate, n- and i-nonyl acrylate, n- and i-decyl acrylate, Straight-chain or branched-chain alkyl acrylates having about 2 to 12 carbon atoms in an alkyl group, such as n-dodecyl acrylate, are exemplified. The alkyl acrylate (b3) may be an alkyl acrylate (cycloalkyl acrylate) having an alicyclic structure, but an alkyl acrylate having 2 to 10 carbon atoms from the viewpoint of followability to an optical film (or flexibility or adhesiveness), etc.; An alkyl acrylate having 3 to 8 carbon atoms is preferred, an alkyl acrylate having 4 to 6 carbon atoms is more preferred, and n-butylalkyl acrylate is particularly preferred. When n-butylalkyl acrylate is used, followability can be increased, and it is advantageous, for example, in peeling resistance. These alkyl acrylates (b3) can be used individually or in combination of 2 or more types.

Examples of the alkyl acrylate (b4) having a homopolymer Tg of 0°C or higher include methyl acrylate, cycloalkyl acrylate (e.g. cyclohexyl acrylate, isobornyl acrylate), stearyl acrylate, t-butyl acrylate and the like. may be used, and methyl acrylate is particularly preferred. The use of methyl acrylate can increase the strength, and is advantageous against, for example, cohesive failure. These alkyl acrylates (b4) can be used individually or in combination of 2 or more types. In addition, for the Tg of the homopolymer of alkyl acrylate, reference can be made to literature values such as POLYMER HANDBOOK (Wiley-Interscience).

In a preferred embodiment, the (meth)acrylic resin (A) is composed of a structural unit derived from an alkyl acrylate (b3) having a glass transition temperature of a homopolymer of less than 0°C and a glass transition of the homopolymer from the viewpoint of improving durability of the pressure-sensitive adhesive layer. The structural unit derived from the alkyl acrylate (b4) whose temperature is 0 degreeC or more is included. When an alkyl acrylate having a homopolymer Tg of less than 0° C. and an alkyl acrylate having a homopolymer Tg of 0° C. or more are used together, cohesive failure resistance and followability (foaming resistance and peeling resistance) can be made compatible, and an optical film ( For example, durability against dimensional change of a polarizing plate) can be improved.

The ratio of the structural units derived from alkyl acrylate in the (meth)acrylic resin (B) is 100 parts by mass of all structural units constituting the (meth)acrylic resin (B) from the viewpoint of durability and reworkability of the pressure-sensitive adhesive layer. , 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, particularly 80 parts by mass or more, preferably 98 parts by mass or less, more preferably 95 parts by mass or less, still more preferably 90 parts by mass or less, and any combination of the lower limit and the upper limit thereof may be used, for example, 50 to 98 parts by mass, preferably 70 to 95 parts by mass, and even more. Preferably it may be 80 to 90 parts by mass.

The ratio (mass ratio) of structural units derived from an alkyl acrylate (b3) having a glass transition temperature of the homopolymer of less than 0°C to structural units derived from an alkyl acrylate (b4) having a glass transition temperature of 0°C or higher is preferably ( b3)/(b4) = 20/80 to 95/5, more preferably 30/70 to 90/10, still more preferably 30/70 to 85/15, particularly 30/70 to 70/30. Durability can be further improved if it is the said range. Followability improves, so that the ratio of the structural unit derived from the alkyl acrylate (b3) whose glass transition temperature is less than 0 degreeC becomes large. Cohesive failure resistance improves, so that the ratio of the structural unit derived from the alkyl acrylate (b4) whose glass transition temperature is 0 degreeC or more increases.

Examples of the alkyl acrylate containing a substituent include an alkyl acrylate in which a substituent is introduced into the alkyl group in the above alkyl acrylate (where the hydrogen atom of the alkyl group is substituted by a substituent). Examples of the substituent include an aryl group (such as a phenyl group), an aryloxy group (such as a phenoxy group), and an alkoxy group (such as a methoxy group and an ethoxy group). Examples of substituent-containing alkyl acrylates include alkoxyalkyl acrylates (e.g., 2-methoxyethyl acrylate, ethoxymethyl acrylate, etc.), arylalkyl acrylates (e.g., benzyl acrylate, etc.), aryloxyalkyl acrylates (e.g., phenoxy cyethyl acrylate, etc.), aryloxy polyalkylene glycol monoacrylate, polyalkylene glycol monoacrylate, and the like. These substituent-containing alkyl acrylates can be used alone or in combination of two or more. Whitening of the polarizing plate at the time of durability test can be improved by containing the alkyl acrylate containing aromatic rings, such as an aryl group, a benzyl group, and an aryloxy group. Moreover, antistatic property at the time of adding an antistatic agent to the adhesive layer can be improved by including an alkoxy group, an aryloxy group, etc. The alkylene group of the aryloxypolyalkylene glycol monoacrylate and polyalkylene glycol monoacrylate may be, for example, a methylene group, an ethylene group, a C _1-6 alkylene group such as a propylene group (preferably an ethylene group), etc. , The number of repeating units of the oxyalkylene group is, for example, 1 to 7, preferably 1 to 5, and particularly 1 to 2, from the viewpoint of balance of durability and antistatic properties of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. Specifically, phenoxydi-hepta C _1-3 alkylene glycol acrylate such as phenoxydiethylene glycol acrylate, di-hepta C _1-3 alkylene monoacrylate such as diethylene glycol monoacrylate, and the like are exemplified. there is. As the substituent-containing alkyl acrylate used in the present invention, it is particularly preferable that they are phenoxyethyl acrylate and phenoxydiethylene glycol acrylate from the viewpoint of durability, whitening resistance, and antistatic balance.

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

The (meth)acrylic resin (B) preferably has a weight average molecular weight (Mw) in terms of standard polystyrene by gel permeation chromatography GPC of 1,000,000 or more in order to further enhance durability of the pressure-sensitive adhesive layer. The lower limit of Mw is more preferably 1.1 million, still more preferably 1.2 million, and particularly 1.3 million. Further, the upper limit of Mw is not particularly limited, but is preferably 2.5 million, more preferably 2.2 million, still more preferably from the viewpoint of coatability when processing the pressure-sensitive adhesive composition into a sheet form (coating to a substrate), for example. is 2 million. Mw may be any combination of these upper limit values and lower limit values, and may be, for example, 1 million to 2.5 million, more preferably 1.1 million to 2.2 million, still more preferably 1.30 to 2 million. The molecular weight distribution expressed by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn (Mw/Mn) is usually 2 to 10, preferably 3 to 8, and more preferably 4 to 6.

In addition, the (meth)acrylic resin (B) preferably has a single peak in the range of Mw of 1.0×10 ³ to 2.5×10 ⁶ on the emission curve in GPC. The use of (meth)acrylic resin (B) having one peak number is advantageous for improving the durability of the pressure-sensitive adhesive layer.

“Having a single peak” in the above range of the obtained emission curve means having only one maximum value in the range of Mw 1.0×10 ³ to 2.5×10 ⁶ . In this specification, in the GPC emission curve, an S/N ratio of 30 or more is defined as a peak. In addition, the number of peaks of the GPC discharge curve and Mw and Mn of the (meth)acrylic resin (B) can be obtained according to the GPC measurement conditions described in the section of Examples.

When the (meth)acrylic resin (B) is dissolved in ethyl acetate to obtain 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. desirable. A viscosity within the above range is advantageous from the viewpoint of coatability when applying the pressure-sensitive adhesive composition to a substrate. In addition, a 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, still more preferably - It may be 40 to -20°C, particularly -40 to -25°C. When Tg is within the above range, it is advantageous to improve the durability of the pressure-sensitive adhesive layer. In addition, a glass transition temperature can be measured with a differential scanning calorimeter (DSC).

The (meth)acrylic resin (B) can be produced by known methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization, and solution polymerization is particularly preferable. As a solution polymerization method, for example, a monomer and an organic solvent are mixed, a thermal polymerization initiator is added under a nitrogen atmosphere, and the mixture is stirred for about 3 to 15 hours under a temperature condition of about 40 to 90°C, preferably about 50 to 80°C. way can be For reaction control, monomers and thermal polymerization initiators may be added continuously or intermittently during polymerization. The monomer or thermal initiator may be added to an organic solvent.

As a polymerization initiator, a thermal polymerization initiator, a photoinitiator, etc. are used. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone and the like. Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 1,1'-azobis(cyclohexane-1-carbonyi). tril), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2' - Azo compounds such as azobis(2-methylpropionate) and 2,2'-azobis(2-hydroxymethylpropionitrile); Lauryl peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, dipropylperoxydicarbonate, t-butylperoxyneodecanoate , organic peroxides such as t-butyl peroxypivalate and (3,5,5-trimethylhexanoyl) peroxide; Inorganic peroxides, such as potassium persulfate, ammonium persulfate, and hydrogen peroxide, etc. are mentioned. In addition, a redox type initiator in which a peroxide and a reducing agent are used in combination or the like can also be used.

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

As an organic solvent, For example, Aromatic hydrocarbons, such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; Ketones, such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, etc. are mentioned.

[1-3] crosslinking agent (C)

The pressure-sensitive adhesive composition may contain a crosslinking agent (C). The crosslinking agent (C) reacts with a reactive group (eg, hydroxyl group) in the (meth)acrylic resin (B). The crosslinking agent (C) forms a crosslinked structure such as a (meth)acrylic resin, and forms a crosslinked structure that is advantageous in durability and reworkability.

Examples of the crosslinking agent (C) include conventional crosslinking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.). In, it is preferable that it is an isocyanate-based compound.

As the isocyanate compound, a compound having at least two isocyanato groups (-NCO) in the molecule is preferable, and examples thereof include aliphatic isocyanate compounds (eg, hexamethylene diisocyanate), alicyclic isocyanate compounds (eg, isophorone) diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylylene diisocyanate diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.) can be heard In addition, the crosslinking agent (C) is an adduct (adduct) of the above isocyanate compound with a polyhydric alcohol compound [for example, an adduct by glycerol, trimethylolpropane, etc.], isocyanurate, biuret-type compound, polyether polyol , polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols and the like, and derivatives of urethane prepolymer type isocyanate compounds obtained by addition reaction. A crosslinking agent (C) can be used individually or in combination of 2 or more types. Among these, typically, aromatic isocyanate-based compounds (eg, tolylene diisocyanate, xylylene diisocyanate), aliphatic isocyanate-based compounds (eg, hexamethylene diisocyanate), or polyhydric alcohol compounds thereof (eg, glycerol, trimethylolpropane) are added. A sieve, or an isocyanurate body is mentioned. If the crosslinking agent (C) is an aromatic isocyanate-based compound and/or a polyhydric alcohol compound thereof, or an adduct of an isocyanurate, it is advantageous for formation of an optimal crosslinking density (or crosslinking structure), or the pressure-sensitive adhesive layer durability can be improved. In particular, if it is an adduct of a tolylene diisocyanate-based compound and/or a polyhydric alcohol compound thereof, durability can be improved even when, for example, a pressure-sensitive adhesive layer is applied to a transparent electrode.

The ratio of the crosslinking agent (C) is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more, and particularly preferably, with respect to 100 parts by mass of the (meth)acrylic resin (B). Preferably 0.2 parts by mass or more, particularly 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 preferably 2 parts by mass or less, extremely It is preferably 1 part by mass or less, particularly 0.8 part by mass or less, and any combination of the lower limit and the upper limit thereof may be used, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass. It may be part by mass, more preferably 0.1 to 2 parts by mass, particularly preferably 0.2 to 1 part by mass, particularly 0.3 to 0.8 parts by mass. If it is less than the upper limit value, it is advantageous to improve the followability (or peeling resistance), and if it is more than the lower limit value, it is advantageous to improve the aggregation resistance (or foam resistance) or rework property.

[1-4] Silane compound (D)

The pressure-sensitive adhesive composition may contain silane compounds (D) other than the siloxane compound (A).

The silane compound (D) may be a silane compound capable of bonding with a reactive group (eg, a hydroxyl group) of the (meth)acrylic resin (B), preferably a silane compound having at least one alkoxy group in the molecule, such as vinyl tree Methoxysilane, Vinyltriethoxysilane, Vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyl Methyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane , 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 1,3-bis(3'-trimethoxypropyl)urea, etc. are mentioned.

In addition, the silane compound (D) may be a silicone oligomer type compound, and when the silicone oligomer is expressed as a combination of monomers, for example, 3-mercaptopropyldi or trimethoxysilane-tetramethoxysilane oligomer, 3 -mercaptomethyldi or trimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyldi or triethoxysilane-tetramethoxysilane oligomer, 3-mercaptomethyldi or triethoxysilane-tetraethoxy mercaptoalkyl group-containing oligomers such as silane oligomers; and oligomers in which the mercaptoalkyl group of the above mercaptoalkyl group-containing oligomer is substituted with another substituent [3-glycidoxypropyl group, (meth)acryloyloxypropyl group, vinyl group, amino group, etc.].

[1-5] antistatic agent

The pressure-sensitive adhesive composition may further contain an antistatic agent. By including an antistatic agent, the antistatic properties of the pressure-sensitive adhesive can be improved (for example, problems caused by static electricity caused when release films, protective films, etc. are peeled off) can be improved. Examples of the antistatic agent include conventional antistatic agents, and ionic antistatic agents are suitable. Examples of the cation component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of organic cations include pyridinium cations, imidazolium cations, ammonium cations, sulfonium cations, and phosphonium cations. Examples of inorganic cations include alkali metal cations such as lithium cations, potassium cations, sodium cations and cesium cations, and alkaline earth metal cations such as magnesium cations and calcium cations. The anion component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, but an anion component containing a fluorine atom is preferable in terms of excellent antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion (PF ₆ ^- ), bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ^- ], bis(fluoro sulfonyl)imide anion [(FSO ₂ ) ₂ N ^- ], tetra(pentafluorophenyl)borate anion [(C ₆ F ₅ ) ₄ B ^- ], and the like. These antistatic agents can be used individually or in combination of 2 or more types. In particular, bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ^- ], bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N ^- ], tetra(pentafluoro The lophenyl)borate anion [(C ₆ F ₅ ) ₄ B ^- ] is preferred. An ionic antistatic agent that is solid at room temperature is preferable in terms of excellent stability over time of antistatic performance of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

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, based on 100 parts by mass of the (meth)acrylic resin (B).

Even if the adhesive composition of this invention contains an antistatic agent, it shows favorable durability in high temperature environment. For this reason, favorable durability and antistatic performance can be made compatible.

[1-6] Other ingredients

The pressure-sensitive adhesive composition may contain one or more additives such as a solvent, a crosslinking catalyst, a UV absorber, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, and light scattering fine particles. Moreover, it is also useful to mix|blend an ultraviolet curable compound with an adhesive composition, and after forming an adhesive layer, harden by irradiating an ultraviolet-ray, and set it as a harder adhesive layer. Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin and melamine resin. etc. can be mentioned.

The pressure-sensitive adhesive composition may contain a rust preventive from the viewpoint of enhancing the metal corrosion resistance of the pressure-sensitive adhesive layer. Examples of the rust inhibitor include triazole-based compounds such as benzotriazole-based compounds; thiazole-based compounds such as benzothiazole-based compounds; imidazole-based compounds such as benzylimidazole-based compounds; imidazoline-based compounds; quinoline-based compounds; pyridine-based compounds; pyrimidine-based compounds; indole-based compounds; amine-based compounds; urea-based compounds; sodium benzoate; benzyl mercapto compounds; di-sec-butylsulfide; and diphenyl sulfoxide.

In a preferred embodiment, the pressure-sensitive adhesive composition of the present invention does not substantially contain a photopolymerization initiator and a decomposition product thereof. This is because there is a possibility that the photopolymerization initiator and its decomposition product in the pressure-sensitive adhesive composition may inhibit formation of a pressure-sensitive adhesive layer having excellent durability. Here, substantially not contained means 1.0 parts by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive composition, preferably 0.1 parts by mass or less, more preferably 0.01 parts by mass or less, still more preferably 0.001 parts by mass or less, In particular, it is most preferable that it is 0 mass part.

[2] Configuration and manufacturing method of pressure-sensitive adhesive layer and optical film with pressure-sensitive adhesive layer

The present invention includes a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition. The pressure-sensitive adhesive layer can be formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to obtain a solvent-containing pressure-sensitive adhesive composition, and then applying and drying the pressure-sensitive adhesive composition on the surface of an optical film or release film.

Moreover, this invention also includes the optical film with an adhesive layer in which the adhesive layer was laminated|stacked on at least one surface of an optical film.

Since the pressure-sensitive adhesive layer and the optical film with a pressure-sensitive adhesive layer of the present invention are formed from the pressure-sensitive adhesive composition, they have excellent durability under severe durability conditions even when applied (or laminated) to a transparent electrode layer such as ITO.

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

When laminating the pressure-sensitive adhesive layer 20 on the surface of the optical film 10, forming a primer layer on the bonding surface of the optical film 10 and/or the bonding surface of the pressure-sensitive adhesive layer 20, or the above surface activation treatment (For example, plasma treatment, corona treatment, etc.) is preferred, and corona treatment is particularly preferred.

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

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

The optical film 1 with the pressure-sensitive adhesive layer may include a separate film (release film) laminated on the outer surface of the pressure-sensitive adhesive layer 20 . This separation film is usually peeled off at the time of use of the pressure-sensitive adhesive layer 20 (for example, at the time of laminating to a transparent electrode or glass substrate). The separate film is, for example, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyalate, etc., on which the surface on which the pressure-sensitive adhesive layer 20 is formed is subjected to release treatment such as silicone treatment. also good

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

The thickness of the pressure-sensitive adhesive layer is usually 2 to 40 μm, and is preferably 5 to 30 μm, more preferably 10 to 25 μm, from the viewpoint of the durability of the optical film with the pressure-sensitive adhesive layer and the reworkability of the optical film with the pressure-sensitive adhesive layer. μm. When the thickness of the pressure-sensitive adhesive layer is equal to or less than the above upper limit, the reworkability becomes good, and when the thickness is equal to or greater than the above lower limit, the followability of the pressure-sensitive adhesive layer to the dimensional change of the optical film becomes good.

The pressure-sensitive adhesive layer preferably exhibits a storage modulus of 0.001 to 10 MPa in a temperature range of 23 to 120°C. Thereby, durability of the optical film with an adhesive layer can be improved more effectively. "It shows a storage modulus of 0.001 to 10 MPa in a temperature range of 23 to 120°C" means that the storage modulus is a value within the above range at any temperature in this range. Since the storage modulus usually decreases gradually as the temperature rises, it can be assumed that the storage modulus within the above range is exhibited at a temperature within this range if both the storage modulus at 23 ° C and 120 ° C are within the above range. The storage modulus of the pressure-sensitive adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, "DYNAMIC ANALYZER RDA II", a viscoelasticity measuring device manufactured by REOMETRIC.

Gel fraction can be used as one indicator of crosslink density. Since the pressure-sensitive adhesive layer of the present invention has a predetermined crosslinking density, it exhibits a predetermined gel fraction. That is, the gel fraction of the pressure-sensitive adhesive layer of the present invention may be, for example, 70 to 90% by mass, preferably 75 to 90% by mass, and more preferably 75 to 85% by mass. When the gel fraction is equal to or greater than the lower limit, the foaming resistance and rework properties of the pressure-sensitive adhesive layer are advantageous, and when the gel fraction is equal to or less than the upper limit, resistance to peeling is advantageous. In addition, the gel fraction can be measured by the method described in the section of 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 force after bonding the adhesive layer of the optical film and the unbonded surface of the optical film with an adhesive layer to a glass substrate and storing for 24 hours under the conditions of a temperature of 23° C. and a relative humidity of 50% is a peel rate of 300 mm/ min, preferably 0.5 to 10 N/25 mm, more preferably 0.7 to 5 N/25 mm. When the adhesive force is equal to or greater than the lower limit, the adhesiveness (or adhesiveness) is improved, and peeling resistance and the like are advantageous, and when the adhesive force is equal to or less than the upper limit, the reworkability is advantageous. In addition, adhesive force can be measured by the method described in the term of an Example, for example.

[2-1] Optical film

The optical film 10 constituting the optical film 1 with the pressure-sensitive adhesive layer may be various optical films (films having optical characteristics) that can be incorporated into image display devices such as liquid crystal display devices. The optical film 10 may have a single-layer structure (for example, a polarizer, a retardation film, a luminance enhancing film, an anti-glare film, an antireflection film, a diffusion film, a condensing film, etc.), or a multi-layer structure (for example, a polarizing plate, a retardation film, etc.) plate, etc.) may be used. The optical film 10 is preferably a polarizing plate, polarizer, retardation plate or retardation film, and particularly preferably a polarizing plate or polarizer. Note that, in this specification, an optical film means a film that functions for displaying images (such as a display screen) (for example, a film that functions to enhance viewing of images). In addition, in this specification, a polarizing plate means that a resin film or a resin layer is laminated on at least one surface of a polarizer, and a retardation plate means a resin film or resin layer laminated on at least one surface of a retardation film.

[2-2] Polarizer

2 and 3 are schematic cross-sectional views showing examples of the layer structure of the polarizing plate. The polarizing plate 10a shown in FIG. 2 is a single-sided protective polarizing plate in which the first resin film 3 is laminated (or laminated) on one side of the polarizer 2, and the polarizing plate 10b shown in FIG. 3 is, A double-sided protective polarizing plate in which a second resin film 4 is further laminated (or laminated) on the other side of the polarizer 2. The 1st, 2nd resin films 3 and 4 can be bonded to the polarizer 2 via the adhesive layer or adhesive layer not shown. Moreover, polarizing plates 10a and 10b may contain films and layers other than the first and second resin films 3 and 4 .

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

A polyvinyl alcohol-type resin can be obtained by saponifying a polyvinyl acetate-type resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and monomers copolymerizable with vinyl acetate (eg, unsaturated carboxylic acid, olefin, vinyl ether, unsaturated sulfonic acid, (meth)acrylamide having an ammonium group, etc.) ) and a copolymer of vinyl acetate, and the like.

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

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

The polarizer 2 includes, for example, a step of uniaxially stretching a raw film, a step of dyeing a film with a dichroic dye and adsorbing the dichroic dye, a step of treating the film with an aqueous solution of boric acid, and washing the film with water. The process is carried out, and at the end it is prepared by drying. The thickness of the polarizer 2 is usually 1 to 30 μm, and from the viewpoint of thinning the optical film 1 with the pressure-sensitive adhesive layer, it is preferably 20 μm or less, more preferably 15 μm or less, and particularly 10 μm or less.

The polarizer 2 formed by adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based resin film uses a single film of the polyvinyl alcohol-based resin film as a raw film, and uniaxial stretching treatment and dyeing of the dichroic dye are performed on this film. In addition to the method of treatment (method (1)), a coating solution (such as an aqueous solution) containing polyvinyl alcohol-based resin is applied to the base film and dried to obtain a base film having a polyvinyl alcohol-based resin layer, This can also be obtained by a method (method (2)) in which each base film is uniaxially stretched, a dichroic dye is dyed on the polyvinyl alcohol-based resin layer after stretching, and then the base film is peeled off. As the base film, a film made of a thermoplastic resin such as a thermoplastic resin capable of constituting the first and second resin films 3 and 4 described later can be used, and preferably polyesters such as polyethylene terephthalate. It is a film made of resins, polycarbonate-based resins, cellulose-based resins such as triacetyl cellulose, cyclic polyolefin-based resins such as norbornene-based resins, and polystyrene-based resins. If the method (2) is used, production of the thin film polarizer 2 becomes easy, and even production of the polarizer 2 having a thickness of 7 μm or less can be easily performed, for example.

The first and second resin films 3 and 4 are independently light-transmitting resin films. The first and second resin films 3 and 4 are preferably made of an optically transparent thermoplastic resin such as a chain polyolefin resin (eg polyethylene resin, polypropylene resin, etc.) or a cyclic polyolefin resin (eg Nord resin). polyolefin-based resins such as bonene-based resins); cellulosic resins (for example, cellulose ester-based resins, etc.); polyester-based resins (for example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc.); polycarbonate-based resins (for example, polycarbonates derived from bisphenols such as 2,2-bis(4-hydroxyphenyl)propane, etc.); (meth)acrylic resin; polystyrene-based resin; polyether ether ketone-based resins; A film made of a polysulfone-based resin or a mixture or copolymer thereof may be used. Among these, the first and second resin films 3 and 4 are films composed of cyclic polyolefin-based resin, polycarbonate-based resin, cellulose-based resin, polyester-based resin, and (meth)acrylic-based resin, respectively. It is preferable that it is, and it is especially preferable that it is a film comprised from a cellulose-type resin, a cyclic polyolefin-type resin, etc.

Examples of chain polyolefin-based resins include homopolymers of chain olefins such as polyethylene resins and polypropylene resins, and copolymers composed of two or more types of chain olefins.

The cyclic polyolefin-based resin is a general term for resins containing, as a polymerized unit, a cyclic olefin representative of norbornene, tetracyclododecene (alias: dimethanooctahydronaphthalene) or derivatives thereof. Examples of the cyclic polyolefin resin include ring-opening (co)polymers of cyclic olefins and their hydrogenated products, addition polymers of cyclic olefins, copolymers of cyclic olefins and chain olefins such as ethylene and propylene, or aromatic compounds having a vinyl group; and modified (co)polymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof. Among these, norbornene-based resins using norbornene-based monomers such as norbornene and polycyclic norbornene-based monomers as cyclic olefins are preferable.

The cellulose-based resin is preferably a cellulose ester-based resin, that is, a partial or complete esterified product of cellulose, and examples thereof include cellulose acetate esters, propionic acid esters, butyric acid esters, and mixed esters thereof. Among these, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like are preferable.

Polyester-based resins are resins other than the above cellulose ester-based resins that have ester bonds, and are generally composed of polycondensates of polyhydric carboxylic acids or derivatives thereof and polyhydric alcohols. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, and polycyclohexane dimethyl. Naphthalate etc. are mentioned.

Polycarbonate-based resin is polyester formed from carbonic acid and glycol or bisphenol. Among these, aromatic polycarbonates having diphenylalkanes in molecular chains are preferable from the viewpoints of heat resistance, weather resistance and acid resistance. Examples of the polycarbonate include 2,2-bis(4-hydroxyphenyl)propane (aka bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl) ) polycarbonate derived from bisphenols such as cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane, and 1,1-bis(4-hydroxyphenyl)ethane; and the like.

The (meth)acrylic resin that can constitute the first and second resin films 3 and 4 can be a polymer mainly composed of a structural unit derived from methacrylic acid ester (for example, containing 50% by mass or more of this), , It is preferable that it is a copolymer in which another copolymerization component is copolymerized here. (meth)acrylic-type resin may contain 2 or more types of structural units derived from methacrylic acid ester. As methacrylic acid ester, _C1 - _C4 alkyl ester of methacrylic acid, such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate, is mentioned.

As a copolymerization component which can be copolymerized with methacrylic acid ester, acrylic acid ester is mentioned. The acrylic acid ester is preferably a C ₁ -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, (alpha)-methylstyrene, and vinyltoluene; vinyl cyan compounds such as (meth)acrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; and compounds other than acrylic acid esters having one polymerizable carbon-carbon double bond in the molecule, such as unsaturated imides such as phenylmaleimide and cyclohexylmaleimide. A compound having two or more polymerizable carbon-carbon double bonds in its molecule may be used as the copolymerization component. A copolymerization component can be used individually or in combination of 2 or more types.

The (meth)acrylic resin may have a cyclic structure in the polymer main chain from the viewpoint of improving the durability of the film. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic imide structure, or a lactone ring structure. Specific examples of the cyclic acid anhydride structure include a glutalic acid anhydride structure and a succinic anhydride structure, and specific examples of the cyclic imide structure include a glutalimide structure and a succinimide structure. Examples of the lactone ring structure include a butyrolactone ring structure and a barellolactone ring structure.

The (meth)acrylic resin may contain acrylic rubber particles from the viewpoint of the film forming property of the film or the impact resistance of the film. The acrylic rubber particles are particles containing an acrylic acid ester-based elastomer as an essential component, and examples include single-layered particles consisting essentially of only the elastic polymer and multi-layered particles containing an elastic polymer as one layer. Examples of the elastic polymer include a cross-linked elastic copolymer obtained by copolymerizing an alkyl acrylate as a main component with another copolymerizable vinyl monomer and a cross-linkable monomer therein. Examples of the alkyl acrylate serving as the main component of the elastic polymer include C ₁ -C ₈ alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. The number of carbon atoms in the alkyl group is preferably 4 or more.

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

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

The first and second resin films 3 and 4 may contain additives common in the technical field of the present invention. Examples of additives include ultraviolet absorbers, infrared absorbers, organic dyes, pigments, inorganic dyes, antioxidants, antistatic agents, surfactants, lubricants, dispersants, and thermal stabilizers. Examples of the ultraviolet absorber include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, triazine compounds, cyano (meth)acrylate compounds, and nickel complex salts.

The first and second resin films 3 and 4 may each be an unstretched film or a uniaxially or biaxially stretched film. The first resin film 3 and/or the second resin film 4 may be a protective film that serves to protect the polarizer 2, or may be a protective film having an optical function such as a retardation film described later. Moreover, the 1st resin film 3 and the 2nd resin film 4 may be the same or different films.

In addition, the first resin film 3 and/or the second resin film 4 has a hard coat layer, an anti-glare layer, an antireflection layer, a light diffusion layer, an antistatic layer, You may be equipped with surface treatment layers (coating layers), such as an antifouling layer and a conductive layer. The thickness of the first resin film 3 and the second resin film 4 is usually 1 to 150 μm, preferably 5 to 100 μm, more preferably 5 to 60 μm, still more preferably 50 μm. ㎛ or less (eg 1 to 40 ㎛), particularly 30 ㎛ or less (eg 5 to 25 ㎛).

In particular, in small and medium-sized polarizing plates such as smartphones and tablet terminals, thin ones with a thickness of 30 μm or less are often used as the first resin film 3 and/or the second resin film 4 because of the demand for thinning. , Such a polarizing plate is weak in the force to suppress the shrinking force of the polarizer 2, and thus the durability is likely to be 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 1st, 2nd resin films 3 and 4 can be bonded to the polarizer 2 via an adhesive bond layer or an adhesive layer. As the adhesive forming the adhesive layer, a water-based adhesive or an active energy ray-curable adhesive can be used.

As the water-based adhesive, conventional water-based adhesives (e.g., adhesives made of polyvinyl alcohol-based resin aqueous solution, aqueous two-component urethane emulsion adhesives, aldehyde compounds, epoxy compounds, melamine-based compounds, methylol compounds, isocyanate compounds, amine compounds, polyvalent crosslinking agents such as metal salts, etc.). Among these, a water-based adhesive composed of a polyvinyl alcohol-based resin aqueous solution can be suitably used. Moreover, when using a water-system adhesive agent, after bonding the polarizer 2 and the 1st, 2nd resin films 3 and 4, it is preferable to perform the process of drying in order to remove the water contained in the water-system adhesive agent. do. After the drying step, a curing step of curing at a temperature of, for example, 20 to 45°C may be provided.

The active energy ray-curable adhesive refers to an adhesive that is cured by irradiating active energy rays such as ultraviolet rays or electron beams, and includes, for example, a curable composition containing a polymerizable compound and a photopolymerization initiator, a curable composition containing a photoreactive resin, and a binder resin. and a curable composition containing a photoreactive crosslinking agent, and the like, preferably an ultraviolet curable adhesive.

When using an active energy ray-curable adhesive, after bonding the polarizer 2 and the 1st, 2nd resin films 3 and 4, performing a drying process as needed, and activating by irradiating an active energy ray then, A curing step of curing the energy ray curable adhesive is performed. The light source of the active energy ray is not particularly limited, but an ultraviolet ray having a luminescence distribution of a wavelength of 400 nm or less is preferable.

As a method of bonding the polarizer 2 and the first and second resin films 3 and 4, at least one of these bonding surfaces is subjected to surface activation treatment such as saponification treatment, corona treatment, plasma treatment, etc. can be heard When a resin film is bonded on both surfaces of the polarizer 2, the same type of adhesive may be sufficient as the adhesive agent for bonding these resin films, and a different type of adhesive agent may be sufficient as it.

The polarizing plates 10a and 10b may further include other films or layers. Specific examples thereof include a retardation film described later, a brightness enhancing film, an antiglare film, an antireflection film, a diffusion film, a condensing film, a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer 20, a coating layer, and a protection film. A protective film is a film used for the purpose of protecting the surface of an optical film 10 such as a polarizing plate from damage or contamination, and is peeled off after bonding the optical film 1 with an adhesive layer onto, for example, a metal layer or a substrate. It is customary to become

A protection film is normally comprised from a base film and the adhesive layer laminated|stacked on it. The base film may be a thermoplastic resin, for example, a polyolefin-based resin such as a polyethylene-based resin or a polypropylene-based resin; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate-based resin; It can be constituted with (meth)acrylic resin or the like.

[2-3] phase plate

As described above, the retardation film included in the retardation plate is an optical film exhibiting optical anisotropy, and can be used for the first and second resin films 3 and 4, in addition to the thermoplastic resins exemplified above, such as polyvinyl Alcohol-based resin, polyarylate-based resin, polyimide-based resin, polyethersulfone-based resin, polyvinylidene fluoride/polymethyl methacrylate-based resin, liquid crystal polyester-based resin, ethylene-vinyl acetate copolymer saponified product, poly It may be a stretched film obtained by stretching a resin film made of a vinyl chloride-based resin or the like by about 1.01 to 6 times. Among these, a stretched film obtained by uniaxially or biaxially stretching a polycarbonate-based resin film, a cyclic olefin-based resin film, a (meth)acrylic-based resin film, or a cellulose-based resin film is preferred. In addition, in this specification, a zero retardation film is also included in the retardation film. However, a zero retardation film can also be used as a protective film. In addition, films called uniaxial retardation film, wide viewing angle retardation film, low photoelasticity retardation film, etc. can also be applied as the retardation film.

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

The in-plane retardation value R _e and the thickness direction retardation value R _th are respectively the following formulas:

R _e = (n _x -n _y )×d

R _th =[(n _x +n _y )/2-n _z ]×d

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

For the zero retardation film, for example, a resin film made of polyolefin resins such as cellulosic resins, chain polyolefin resins and cyclic polyolefin resins, polyethylene terephthalate resins, or (meth)acrylic resins can be used. In particular, cellulose-based resins, polyolefin-based resins, or (meth)acrylic-based resins are preferably used in terms of easy control of the retardation value and easy availability.

In addition, a film in which optical anisotropy is expressed by application and orientation of a liquid crystalline compound or a film in which optical anisotropy is expressed by application of an inorganic layer type compound can also be used as a retardation film. Such a retardation film includes what is called a temperature compensation type retardation film, a film in which rod-shaped liquid crystals are obliquely aligned and sold under the trade name of "NH film" from JXTG Energy Co., Ltd., and "WV" from Fuji Film Co., Ltd. A film in which disk-shaped liquid crystals are obliquely oriented sold under the trade name of "Film", a completely biaxially oriented film sold under the trade name of "VAC film" from Sumitomo Chemical Co., Ltd., and "new VAC" from Sumitomo Chemical Co., Ltd. There are biaxially oriented films and the like sold under the trade name of "Film". Moreover, the resin film laminated|stacked on at least one surface of retardation film may be the above-mentioned protective film, for example.

[3] Optical laminate

The present invention includes an optical laminate comprising the optical film with a pressure-sensitive adhesive layer. Preferably, the optical layered body includes the optical film with a pressure-sensitive adhesive layer and the base material laminated on the pressure-sensitive adhesive layer side of the optical film with a pressure-sensitive adhesive layer.

Examples of the substrate include conventional substrates such as glass substrates, plastic films, organic conductive films, metal layers, and overcoat resin layers. Since the pressure-sensitive adhesive layer is formed of the pressure-sensitive adhesive composition, the optical laminate of the present invention has excellent durability under severe durability conditions even when a transparent electrode layer such as ITO or a metal layer such as metal mesh (metal wiring layer) is used as a base material. .

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

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

The optical layered body 6 shown in FIG. 5 includes the electrode layer 30 laminated on the substrate 40 on the side of the adhesive layer side of the optical film 1b with an adhesive layer (or the polarizing plate with an adhesive layer 1b). It is an optical laminate laminated on. The said optical film 1b with an adhesive layer is an optical film in which the adhesive layer 20 was laminated|stacked on the 2nd resin film 4 side surface of the said polarizing plate 10b.

The optical laminates 5 and 6 can be obtained by bonding the optical films 1a and 1b with the pressure-sensitive adhesive layer to the electrode layer 30 laminated on the substrate 40 via the pressure-sensitive adhesive layer 20. .

As a method of forming the electrode layer 30 on the substrate 40, a sputtering method or the like is exemplified. The substrate 40 may be a transparent substrate constituting a liquid crystal cell included in the touch input element, and is preferably a glass substrate. As a material of the glass substrate, soda lime glass, low alkali glass, alkali free glass or the like can be used. The electrode layer 30 may be formed on the entire surface of the substrate 40 or may be formed on a part thereof.

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

Examples of the transparent electrode layer include layers composed of tin oxide, indium oxide, zinc oxide, gallium oxide, aluminum oxide, and mixtures thereof. It is preferably ITO in view of conductivity and visible light transmittance.

Examples of the metal layer include a layer containing at least one metal element selected from aluminum, copper, silver, iron, tin, zinc, nickel, molybdenum, chromium, tungsten, lead, and alloys containing two or more metals thereof. can be heard Among these, from the viewpoint of conductivity, it is preferably a metal layer containing at least one metal element selected from aluminum, copper, silver and gold, more preferably at least one metal selected from aluminum, copper and silver It is a layer containing elements.

Further, the metal layer may be a metal mesh in which a thin metal wiring layer is disposed on a substrate, or a layer in which metal nanoparticles or metal nanowires are added to a binder.

The preparation method of the electrode layer 30 is not particularly limited, and may be formed by a vacuum deposition method, sputtering method, ion plating method, inkjet printing method, or gravure printing method.

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

The thickness of the electrode layer 30 is not particularly limited, but is usually 3 μm or less, preferably 1 μm or less, more preferably 0.8 μm or less, and usually 0.01 μm or more. Further, when the electrode layer 30 is a metal wiring layer (eg, 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. am.

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

The optical laminate 8 shown in FIG. 7 has a resin layer 50 further laminated on the surface of the electrode layer 30 laminated on the substrate 40 (on the surface opposite to the substrate 40), It is an optical laminated body laminated on the surface of the pressure-sensitive adhesive layer (20) side of the optical film (1) with the pressure-sensitive adhesive layer. As a resin which forms the resin layer 50, the resin etc. which comprise the 1st or 2nd resin film illustrated above are mentioned, for example.

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

In the optical layered body 9, the plurality of electrode layers 30 may or may not contact the pressure-sensitive adhesive layer 20 in whole or in part. Further, the electrode layer 30 may be a continuous film containing the above metal or alloy. In addition, the resin layer 50 may be omitted.

After bonding the optical films 1, 1a, 1b with an adhesive layer and the substrate 40 (glass substrate, transparent substrate, etc.) or the electrode layer 30 to produce an optical laminate, if there is any problem, the adhesive A so-called rework operation in which the optical film with a layer is peeled off from the substrate 40 or the electrode layer 30 and the optical film 1 with a pressure-sensitive adhesive layer is adhered again to the substrate 40 or the electrode layer 30 becomes necessary. There are cases. The optical film 1 with a pressure-sensitive adhesive layer according to the present invention is resistant to opacity and scum of glue on the surface of the glass substrate or electrode layer (for example, a transparent conductive layer such as ITO) after peeling, and is excellent in reworkability. .

[4] Liquid crystal display

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

The liquid crystal display device may be a touch input type liquid crystal display device having a touch panel function. A touch input type liquid crystal display device includes a touch input element including a liquid crystal cell and a backlight. The configuration of the touch panel may be a known method (for example, an out-cell type, an on-cell type, an in-cell type, etc.), and the operation method of the touch panel may be a known method, for example, a resistive film type, a capacitance type (surface type capacitance type) , projected capacitance method), etc. may be used. The optical film with an adhesive layer concerning this invention may be arrange|positioned on the visual recognition side of a touch input element (liquid crystal cell), may be arrange|positioned on the backlight side, and may be arrange|positioned on both sides. The driving system of the liquid crystal cell may be any conventionally known system such as a TN system, a VA system, an IPS system, a multi-domain system, or an OCB system. In the liquid crystal display device, the substrate 40 included in the optical layered body may be a substrate (typically a glass substrate) included in the liquid crystal cell.

[5] Siloxane compound for adhesive (A)

This invention contains the siloxane compound (A) for adhesives. The siloxane compound (A) for an adhesive is the same as the siloxane compound (A) described above, and the ratio of alkoxy groups in the hydrolysis-condensation product (a), the weight average molecular weight of the hydrolysis-condensation product (a), and a preferred range thereof etc. are also the same. Moreover, although it does not specifically limit as an adhesive layer to which the siloxane compound (A) for adhesives is applied, Preferably the adhesive layer which consists of the adhesive composition of the said [1] is mentioned.

Example

Hereinafter, the present invention will be described more specifically by showing examples and comparative examples, but the present invention is not limited by these examples. Hereinafter, unless otherwise specified, parts and % showing usage amount and content are based on mass.

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

A solution obtained by mixing a monomer having a composition shown in Table 1 (numerals in Table 1 are parts by mass) with 81.8 parts of ethyl acetate was injected into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer. After replacing the air in the reaction vessel with nitrogen gas, the internal temperature was set 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 the same temperature for 1 hour, ethyl acetate was continuously added into the reaction vessel at an addition rate of 17.3 parts/Hr so that the concentration of the polymer was approximately 35% while maintaining the internal temperature at 54 to 56°C. After maintaining the internal temperature at 54 to 56°C until 12 hours elapsed from the start of addition of ethyl acetate, ethyl acetate was further added to adjust the polymer concentration to 20%, and the (meth)acrylic resin (B-1) An ethyl acetate solution was obtained. The weight average molecular weight Mw of the obtained (meth)acrylic resin (B-1) was 1,380,000, 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 of (meth)acrylic resin (B-2) was obtained in the same manner as in Production Example 1 except that the composition of the monomer was set to the composition shown in Table 1 (resin concentration: 20%). The weight average molecular weight Mw of the obtained (meth)acrylic resin (B-2) was 1,420,000, and Mw/Mn was 5.2.

In the above Production Example, the weight average molecular weight Mw and the number average molecular weight Mn were measured using 4 "TSKgel XL" manufactured by Tosoh Corporation as a column in a GPC apparatus and "Shodex GPC KF- manufactured by Showa Denko Corporation" 802” was placed in series, using tetrahydrofuran as an eluent, and under conditions of a sample concentration of 5 mg/mL, a sample introduction amount of 100 μL, a temperature of 40° C., and a flow rate of 1 mL/min, It was measured by standard polystyrene conversion. The conditions for obtaining the emission curve of GPC were also made the same as this.

The glass transition temperature Tg was measured using a differential scanning calorimeter (DSC) "EXSTAR DSC6000" manufactured by SI Nano Technology Co., Ltd., in a nitrogen atmosphere, in a measurement temperature range of -80 to 50 ° C, and at a heating rate of 10 ° C / min. was measured under the condition of

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

Abbreviated names in the column of "monomer composition" in Table 1 mean the following monomers.

BA: normal 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 acid.

<Preparation Example 3: Manufacturing method of siloxane compound A-1>

326 parts of 1,6-bistrimethoxysilylhexane and 97.2 parts of methanol were charged into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirrer. After replacing the air in the reaction vessel with nitrogen gas, the internal temperature was set to 25°C. Thereafter, a mixed solution obtained by mixing 0.6 parts of a 1N hydrochloric acid aqueous solution, 10.2 parts of water, and 10.2 parts of methanol was added to the reaction vessel. After stirring the obtained mixture for 1 hour, it was refluxed for 2 hours. After cooling, 1.0 part of a 10% sodium acetate methanol solution was added to the resulting mixture, and reflux was further performed for 2 hours. Solvent distillation was performed from the obtained mixture to obtain a siloxane compound (A-1).

The weight average molecular weight of the obtained siloxane compound (A-1) was 1300. Further, from ¹ H-NMR, it was confirmed that 20% of the alkoxy groups were hydrolyzed without contradicting the amount of water added. That is, the content of alkoxy groups contained in the siloxane compound (A-1) is 80 mol% with respect to 100 mol% of the total amount of alkoxy groups contained in 1,6-bistrimethoxysilylhexane.

<Production Example 4: Manufacturing method of siloxane compound A-2>

326 parts of 1,6-bistrimethoxysilylhexane and 97.2 parts of methanol were charged into a reaction vessel equipped with a cooling tube, a thermometer and a stirrer. After replacing the air in the reaction vessel with nitrogen gas, the internal temperature was set to 25°C. Thereafter, a mixed solution obtained by mixing 0.6 parts of a 1N hydrochloric acid aqueous solution, 7.5 parts of water, and 10.2 parts of methanol was added to the reaction vessel. After stirring the obtained mixture for 1 hour, reflux was performed for 2 hours. After cooling, 1.0 part of a 10% sodium acetate methanol solution was added to the resulting mixture, and reflux was further performed for 2 hours. Solvent distillation was performed 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. Further, from ¹ H-NMR, it was confirmed that 15% of the alkoxy groups were hydrolyzed without contradicting the amount of water added. That is, the content of alkoxy groups contained in the siloxane compound (A-2) is 85 mol% with respect to 100 mol% of the total amount of alkoxy groups contained in 1,6-bistrimethoxysilylhexane.

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

(1) Preparation of pressure-sensitive adhesive composition

Siloxane compound (A) in an amount (parts by mass) shown in Table 2, a crosslinking agent ( C), in Examples 4, 7 and 8, an antistatic agent (E) was further mixed, and then ethyl acetate was added so that the solid concentration was 14% to obtain an adhesive composition. The compounding amount of each compounding component shown in Table 2 is the number of parts by mass of the active ingredient contained therein, when the product used contains a solvent or the like.

The details of each compounding component shown by abbreviation in Table 2 are as follows.

(siloxane compound (A))

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

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

A-3: manufactured by Shin-Etsu Chemical 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: manufactured by Tosoh Co., Ltd., trade name "Colonate L" (ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration: 75%))

(Antistatic agent (E))

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

(2) Production of pressure-sensitive adhesive layer

Each pressure-sensitive adhesive composition prepared in (1) above was dried using an applicator on a release-treated surface of a release-treated polyethylene terephthalate film [trade name “PLR-382051” obtained from Lintech Co., Ltd.] It was applied so as to have a thickness of 20 μm and dried at 100° C. for 1 minute to prepare a pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet).

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

A polyvinyl alcohol film having an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol%, and a thickness of 60 μm [trade name “Kuraray Vinylon VF-PE#6000” manufactured by Kuraray Co., Ltd.] was immersed in pure water at 37° C. It was immersed at 30 degreeC in the aqueous solution (iodine/potassium iodide/water (mass ratio) = 0.04/1.5/100) containing iodine and potassium iodide. Then, it was immersed at 56.5 degreeC in the aqueous solution (potassium iodide/boric acid/water (mass ratio) = 12/3.6/100) containing potassium iodide and boric acid. The film was washed with pure water at 10°C and then dried at 85°C to obtain a polarizer having a thickness of about 23 μm in which iodine was adsorbed and oriented in polyvinyl alcohol. Stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times.

A transparent protective film [trade name “KC2UA” manufactured by Konica Minolta Opto Co., Ltd.] made of a triacetyl cellulose film having a thickness of 25 μm was bonded to one side of the obtained polarizer through an adhesive made of an aqueous solution of polyvinyl alcohol-based resin. Next, on the surface opposite to the triacetyl cellulose film in the polarizer, a zero phase difference film made of a cyclic polyolefin-based resin having a thickness of 23 μm [trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.] was applied to a polyvinyl alcohol-based A polarizing plate was produced by bonding through an adhesive composed of an aqueous solution of the resin. Subsequently, corona discharge treatment is applied to the surface opposite to the surface in contact with the polarizer in the zero retardation film, and then the surface opposite to the separate film of the pressure-sensitive adhesive layer produced in (2) above (pressure-sensitive adhesive layer surface) After bonding together by a laminator, it cured for 7 days on conditions of the temperature of 23 degreeC, and the relative humidity of 65%, and the optical film with an adhesive layer (P-1) was obtained.

(4) Evaluation of durability of optical film with pressure-sensitive adhesive layer

The optical film with the pressure-sensitive adhesive layer (P-1) produced in (3) above is cut into a size of 300 mm x 220 mm so that the direction of the stretching axis of the polarizing plate becomes the long side, the separate film is peeled off, and the exposed pressure-sensitive adhesive layer surface is glass. It was bonded to a substrate or a glass substrate with ITO (tin-doped indium oxide). The obtained test piece (optical film with an adhesive layer to which the glass substrate was adhered) to which the glass substrate was bonded was pressurized for 20 minutes at a temperature of 50°C and a pressure of 5 kg/cm 2 (490.3 kPa) in an autoclave. As the glass substrate, an alkali-free glass trade name "Eagle XG" manufactured by Corning Co., Ltd. was used. Moreover, as a glass substrate with ITO, what formed the ITO layer of 30 nm by ITO vapor deposition on alkali-free glass by Corning Corporation (brand name "Eagle XG") was used. About the obtained optical laminated body, the following durability test was implemented.

[Durability test]

ㆍHeat resistance test maintained for 1000 hours under dry condition of 95℃, (glass substrate)

ㆍHeat resistance test maintained for 1000 hours under dry conditions at a temperature of 95℃, (ITO-attached glass)

ㆍMoisture heat resistance test (glass substrate) maintained for 1000 hours at a temperature of 60°C and a relative humidity of 90%.

• Heat shock resistance (HS) test (glass substrate) in which an operation of holding for 30 minutes under drying conditions at a temperature of 85 ° C. and then holding for 30 minutes under drying conditions at a temperature of -40 ° C. is repeated 1000 cycles as one cycle.

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

5: No change in appearance, such as lifting, peeling, or foaming, was observed.

4: Almost no change in appearance such as lifting, peeling, foaming, etc.

3: Slight appearance changes such as lifting, peeling, and foaming are seen.

2: Appearance changes such as lifting, peeling, and foaming are conspicuous.

1: Significant changes in appearance, such as lifting, peeling, and foaming, are observed.

However, when it is 3 or more, durability is good.

(5) Evaluation of the adhesive strength of the optical film with the pressure-sensitive adhesive layer

The optical film with a pressure-sensitive adhesive layer (P-1) produced in the above (3) was cut into a test piece having a size of 25 mm x 150 mm. The separator was peeled off from the test piece, and the adhesive side was adhered to the glass substrate. The obtained test piece (optical film with pressure-sensitive adhesive layer to which the glass substrate was adhered) to which the glass substrate was bonded was pressurized for 20 minutes at a temperature of 50°C and a pressure of 5 kg/cm 2 (490.3 kPa) in an autoclave. After storing for 24 hours in an atmosphere at a temperature of 23°C and a relative humidity of 50%, the optical film was peeled from the test piece together with the pressure-sensitive adhesive layer 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 adhesive force.

When the adhesive force is 6 N or less, the reworkability is excellent, and when it is 0.5 N or more, peeling hardly occurs even when an impact is received from the end portion of the polarizing plate.

(6) Evaluation of antistatic properties of optical films with pressure-sensitive adhesive layers

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

[Gel fraction of pressure-sensitive adhesive sheet]

The gel fraction evaluation method of the pressure-sensitive adhesive sheet of the present invention is shown. The larger the gel fraction, the more crosslinking reactions proceed in the pressure-sensitive adhesive, and it can be used as a criterion for crosslinking density. The gel fraction is a value measured according to the following (a) to (d).

(a) A pressure-sensitive adhesive sheet having an area of about 8 cm×about 8 cm and a metal mesh made of SUS304 having an area of about 10 cm×about 10 cm (its mass being Wm) are bonded.

(b) The bonded product obtained in (I) is weighed, its mass is taken as Ws, and then it is folded over four times so as to wrap the adhesive sheet and fixed with a stapler, then weighed, and its mass is taken as Wb.

(c) Put the stapler-fixed mesh in (II) above into a glass container, add 60 mL of ethyl acetate to immerse it, and then store the glass container at room temperature for 3 days.

(d) The mesh is taken out from the glass container, dried at 120° C. for 24 hours, then weighed, the mass is defined as Wa, and the gel fraction is calculated based on the following formula.

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

The optical films with an adhesive layer obtained in Examples 1 to 9 exhibited good durability even under severe durability conditions. Even when applied to an ITO substrate, good durability was exhibited. Moreover, it was confirmed that it also had good reworkability and could make both durability and reworkability compatible.

DESCRIPTION OF SYMBOLS 1, 1a, 1b: Optical film with adhesive layer, 2: Polarizer, 3: 1st resin film, 4: 2nd resin film, 5, 6, 7, 8, 9: Optical laminated body, 10: Optical film, 10a , 10b: polarizer, 20: pressure-sensitive adhesive layer, 30: electrode layer, 40: substrate, 50: resin layer.

Claims (15)

A pressure-sensitive adhesive composition comprising a siloxane compound (A), a (meth)acrylic resin (B) and a crosslinking agent (C),
The siloxane compound (A) has the following formula (a1)

(Wherein, 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 alkanediyl group and the alicyclic hydrocarbon group is -O- or - may be substituted with 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 an alkyl group having 1 to 5 carbon atoms or a carbon atom 1 to 5 carbon atoms represents an alkoxy group of 5)
An adhesive composition that is a hydrolysis condensation product (a) of a hydrolysis condensation silane compound represented by The pressure-sensitive adhesive composition according to claim 1, wherein the content of alkoxy groups contained in the siloxane compound (A) is 60 to 95 mol% with respect to 100 mol% of the total amount of alkoxy groups contained in the hydrolytic condensation silane compound (a1). The pressure-sensitive adhesive composition according to claim 1, wherein the weight average molecular weight of the siloxane compound (A) is 600 to 4000 in terms of polystyrene. The adhesive composition according to claim 1, wherein the ratio of the siloxane compound (A) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (B). The (meth)acrylic resin (B) according to claim 1, wherein the (meth)acrylic resin (B) comprises a constitutional unit derived from an alkyl acrylate (b1) having a homopolymer glass transition temperature of less than 0°C, and an alkyl acrylate having a homopolymer glass transition temperature of 0°C or higher. The pressure-sensitive adhesive composition comprising a constituent unit derived from rate (b2). The ratio of the constituent units derived from the carboxyl group-containing (meth)acrylate contained in the (meth)acrylic resin (B) is 100 parts by mass of all constituent units constituting the (meth)acrylic resin (B) according to claim 1 1.0 parts by mass or less relative to the pressure-sensitive adhesive composition. The adhesive composition according to claim 1, wherein the (meth)acrylic resin (B) has a weight average molecular weight of 100 to 2.5 million in terms of polystyrene. The pressure-sensitive adhesive composition according to claim 1, wherein the crosslinking agent (C) is an isocyanate-based compound. The adhesive composition according to claim 1, wherein the ratio of the crosslinking agent (C) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (B). A pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 9. The optical film with an adhesive layer in which the adhesive layer of Claim 10 was laminated|stacked on at least one surface of an optical film. The method of claim 11, wherein the adhesive strength after bonding the pressure-sensitive adhesive layer on the surface of the optical film with the pressure-sensitive adhesive layer to the glass substrate and storing for 24 hours under conditions of a temperature of 23 ° C. and a relative humidity of 50% is, An optical film with an adhesive layer that is 0.5 to 10 N/25 mm at a peel rate of 300 mm/min. An optical laminate comprising the optical film with a pressure-sensitive adhesive layer according to claim 11. Equation (a1)

(Wherein, 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 alkanediyl group and the alicyclic hydrocarbon group is -O- or - may be substituted with 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 an alkyl group having 1 to 5 carbon atoms or a carbon atom 1 to 5 carbon atoms represents an alkoxy group of 5)
It is a hydrolytic condensation product (a) of a hydrolysis condensable silane compound represented by
The siloxane compound (A) for adhesives whose weight average molecular weight is 600-4000 in conversion of polystyrene. delete

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