TWI761517B - Adhesive composition - Google Patents

Abstract

The present invention provides an adhesive composition containing a siloxane compound (A) which is a hydrolytic condensate (a) of a hydrolyzable condensable silane compound represented by the following formula (a1).

(In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH₂- in the alkanediyl group and the alicyclic hydrocarbon group may be replaced by -O- or -CO-, R¹ and R² each independently represents an alkyl group having 1 to 5 carbon atoms, R³, R⁴, R⁵ and R⁶ each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms)

Description

adhesive composition

The present invention claims the priority of Japanese Patent Application No. 2017-103018 (filing date: May 24, 2017 ) based on the Paris Convention, the entirety of which is incorporated herein by reference.

The present invention relates to an adhesive composition useful as an optical member used in liquid crystal display devices, etc., an adhesive layer composed of the adhesive composition, an optical film containing the adhesive layer and the adhesive layer, and an adhesive layer containing the adhesive The optical laminate of the optical film of the adhesive layer, and the siloxane compound for the adhesive.

Optical films typified by polarizers formed by laminating a transparent resin film on one side or both sides of a polarizer are widely used as optical members constituting image display devices such as liquid crystal display devices. Most of the optical films such as polarizing plates are used by being bonded to other members (eg, liquid crystal cells in a liquid crystal display device) through an adhesive layer (refer to Patent Document 1). Therefore, as an optical film, the optical film which provided the adhesive bond layer of the adhesive bond layer on one surface in advance is known.

[Prior Art Literature] [Patent Literature]

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

In recent years, liquid crystal display devices have been developed for use in mobile devices such as smart phones and tablet terminals, and in vehicle-mounted devices such as car navigation systems. In such a use, there is a possibility of being exposed to a harsh environment compared with the conventional indoor TV use, and thus the problem of improving the durability of the apparatus arises.

Durability is similarly required to the optical film which comprises the adhesive bond layer of a liquid crystal display device etc. similarly. That is, the adhesive layer assembled in the liquid crystal display device, etc., will be placed in a high temperature or high temperature and high humidity environment, or in an environment where high temperature and low temperature are repeated, so the optical film with the adhesive layer is expected to be even In such an environment, it is also possible to suppress problems such as floating or peeling of the interface between the adhesive layer and the optical member to which it is attached, and foaming of the adhesive layer, and it is also expected that the optical properties do not deteriorate. In particular, the optical film with the adhesive layer is used (laminated or laminated) on a touch panel with a transparent electrode such as ITO (indium tin oxide), etc., especially under the above-mentioned severe durability conditions, it is difficult to exhibit high durability situation, and it is required to have high durability performance in this situation.

Therefore, the object of the present invention is to provide an adhesive composition, an adhesive layer composed of the adhesive composition, an optical film containing the adhesive layer and the adhesive layer, and an optical film containing the adhesive layer. Optical laminates, and siloxane compounds for adhesives, even when the adhesive composition is used for transparent electrode layers such as ITO, an adhesive layer that exhibits good durability can be formed under severe durability conditions.

The inventors of the present invention have made diligent studies in order to solve the above-mentioned problems, and as a result, they have completed the present invention. That is, the present invention includes the following.

(式中，B表示碳數1至20之烷烴二基(alkanediyl)或碳數3至20之二價之脂環式烴基，構成前述烷烴二基及前述脂環式烴基之-CH₂-可被-O-或-CO-取代，R¹及R²係分別獨立地表示碳數1至5之烷基，R³、R⁴、R⁵及R⁶係分別獨立地表示碳數1至5之烷基或碳數1至5之烷氧基)。 [1] An adhesive composition comprising a siloxane compound (A) which is a hydrolysis condensate (a) of a hydrolysis condensable silane compound represented by the following formula (a1),

(in the formula, B represents an alkanediyl having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH ₂ - which constitutes the aforementioned alkanediyl and the aforementioned alicyclic hydrocarbon group can be Substituted by -O- or -CO-, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a carbon number of 1 to 5 alkyl or alkoxy with 1 to 5 carbon atoms).

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

[3] The adhesive composition according to [1] or [2], wherein the weight average molecular weight of the siloxane compound (A) is 600 to 4,000 in terms of polystyrene.

[4] The adhesive composition according to any one of [1] to [3], which further contains 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 relative to 100 parts by mass of the (meth)acrylic resin (B).

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

[7] The adhesive composition according to any one of [4] to [6], wherein the (meth)acrylic resin (B) contains a compound derived from a carboxyl group-containing (meth)acrylate The ratio of a structural unit is 1.0 mass part or less with respect to 100 mass parts of total structural units which comprise (meth)acrylic-type resin (B).

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

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

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

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

[12] An optical film with an adhesive layer, which is obtained by laminating the adhesive layer described in [11] on at least one side of the optical film.

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

[14] An optical laminate comprising an optical film containing the adhesive layer according to [12] or [13].

(式中，B表示碳數1至20之烷烴二基或碳數3至20之二價之脂環式烴基，構成前述烷烴二基及前述脂環式烴基之-CH₂-可被-O-或-CO-取代，R¹及R²係分別獨立地表示碳數1至5之烷基，R³、R⁴、R⁵及R⁶係分別獨立地表示碳數1至5之烷基或碳數1至5之烷氧基)。 [15] A siloxane compound (A) for an adhesive, which is a hydrolysis condensate (a) of a hydrolysis condensable silane compound represented by 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 aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group may be replaced by -O - or -CO-substituted, R ¹ and R ² each independently represent an alkyl group with 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group with 1 to 5 carbon atoms or alkoxy with 1 to 5 carbon atoms).

Even when the adhesive composition of the present invention is used in a transparent electrode layer such as ITO, an adhesive layer with good durability can be formed under severe durability conditions.

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

2‧‧‧Polarizer

3‧‧‧First resin film

4‧‧‧Second resin film

5, 6, 7, 8, 9‧‧‧optical laminate

10‧‧‧Optical Film

10a, 10b‧‧‧Polarizer

20‧‧‧Adhesive layer

30‧‧‧Electrode layer

40‧‧‧Substrate

50‧‧‧Resin layer

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

FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of the polarizing plate.

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

Fig. 4 is a schematic cross-sectional view showing an example of an optical laminate including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

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

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

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

Fig. 8 is a schematic cross-sectional view showing yet another example of an optical laminate including an optical film with an adhesive layer formed from the adhesive composition of the present invention.

[1] Adhesive composition

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

[1-1] Siloxane compound (A)

The siloxane compound (A) is a hydrolysis condensate (a) of a hydrolysis condensable silane compound represented by the following formula (a1).

(式中，B表示碳數1至20之烷烴二基或碳數3至20之二價之脂環式烴基，構成前述烷烴二基及前述脂環式烴基之-CH₂-可被-O-或-CO-取代。

(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 aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group may be replaced by -O - or -CO- substituted.

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

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

In formula (a1), B represents an alkanediyl group having 1 to 20 carbon atoms such as methylene, ethylidene, propylidene, butylene, hexylene, heptyl, and octyl; cyclobutenyl (eg 1,2-cyclobutenyl), cyclopentenyl (eg 1,2-cyclopentenyl), cyclohexenyl (eg 1,2-cyclohexenyl), cyclooctenyl (eg 1,2-cyclooctenyl) and other bivalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms; or -CH ₂ - which constitutes these alkanediyl groups and the aforementioned alicyclic hydrocarbon groups, is -O- or -CO- substituted base. Desirable B is an alkanediyl group having 1 to 10 carbon atoms.

R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tertiary butyl group, a tertiary butyl group, a pentyl group and the like having 1 to 5 carbon atoms. or alkoxy with 1 to 5 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, secondary butoxy, tertiary butoxy, etc. Preferably, R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkoxy group having 1 to 5 carbon atoms.

The alkyl group having 1 to 5 carbon atoms represented by R ¹ and R ² is, for example, the same as the alkyl group having 1 to 5 carbon atoms represented by R ³ , R ⁴ , R ⁵ and R ⁶ .

Specific silane compound (a1), for example, bis(trimethoxysilyl)methane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane Alkane, 1,3-bis(trimethoxysilyl)propane, 1,3-bis(triethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,4- Bis(triethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,5-bis(triethoxysilyl)pentane, 1,6-bis(trimethyl) oxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,6-bis(tripropoxysilyl)hexane, 1,8-bis(trimethoxysilyl)hexane bis(tri-C _1-5 alkoxysilyl) octane, 1,8-bis(triethoxysilyl)octane, 1,8-bis(tripropoxysilyl)octane, etc. C _1-10 alkanes; bis(dimethoxysilyl)methane, 1,2-bis(dimethoxysilyl)ethane, 1,2-bis(diethoxysilyl)ethane, 1 ,4-bis(dimethoxysilyl)butane, 1,4-bis(diethoxysilyl)butane, 1,6-bis(dimethoxysilyl)hexane, 1,6 - Bis(diethoxysilyl)hexane, 1,8-bis(dimethoxysilyl)octane, 1,8-bis(diethoxysilyl)octane, etc. bis( _diC1 ) _-5 alkoxy C _1-5 alkylsilyl) C _1-10 alkane; 1,6-bis(methoxydimethylsilyl)hexane, 1,8-bis(methoxydimethylsilyl) Silyl) octane and other bis(mono-C _1-5 alkoxy-di-C _1-5 alkylsilyl) C _1-10 alkanes, etc. Among them, 1,2-bis(trimethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane are preferred bis(trimethoxysilyl) alkane, 1,5-bis(trimethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane, etc. C _1-3 alkoxysilyl) C _1-10 alkane, particularly preferably 1,6-bis(trimethoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane.

The hydrolyzable condensate (a) of the hydrolyzable condensable silane compound (hereinafter, also referred to as the hydrolyzable condensable silane compound (a1)) represented by the aforementioned formula (a1) refers to the hydrolyzable group in the hydrolyzable condensable silane compound (a1) The alkoxy group is the condensate obtained by hydrolysis and condensation, such as dimer or oligomer. In addition, the hydrolysis condensate (a) may be a hydrolysis condensate (also referred to as a partial hydrolysis condensate) obtained by partial hydrolysis and condensation of an alkoxy group of the hydrolyzable condensable silane compound (a1), or the alkoxy group. All hydrolyzed and condensed condensates. In addition, the alkoxy group of the hydrolyzable condensable silane compound (a1) is hydrolyzed into a hydroxyl group, and the resulting hydroxyl group is condensed, or a part of the hydroxyl group is not condensed and remains in the hydrolysis condensate (a).

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

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

Also, in this specification, the term "durability" means that, for example, in a high-temperature environment, a high-temperature and high-humidity environment, an environment where high temperature and low temperature are repeated, etc., the interface between the adhesive layer and its adjacent optical member can be suppressed from floating or peeling off. properties (also referred to as peel resistance), and properties that suppress undesirable situations such as foaming of the adhesive layer (also referred to as anti-foaming properties). In addition, in this specification, the so-called anti-agglutination failure property refers to the property of suppressing coagulation failure (or cracking) of the adhesive layer.

The hydrolysis-condensation product (a) is preferably a partial hydrolysis-condensation product of the hydrolysis-condensable silane compound (a1). The content of the alkoxy groups contained in the siloxane compound (A) is preferably 60 mol % or more, more preferably 100 mol % of the total amount of the alkoxy groups contained in the hydrolyzable condensable silane compound (a1). Preferably it is 65 mol % 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, and the like The limit value and the upper limit value can be combined arbitrarily, for example, it can be 60 to 95 mol %, preferably 65 to 90 mol %, more preferably 70 to 88 mol %. When the content of the alkoxy group contained in the siloxane compound (A) is more than the above lower limit value, the durability of the adhesive layer can be further improved, and when it is below the above upper limit value, the durability of the adhesive layer can be further improved. Reworkability.

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

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

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

In addition to the hydrolysis condensate (a), the siloxane compound (A) may contain an uncondensed hydrolysis condensable silane compound (a1) alone or in two or more kinds. In addition, when the hydrolysis condensable silane compound (a2) is used together, the siloxane compound (A) may contain an uncondensed hydrolysis condensable silane compound (a2). The alkoxy group of the uncondensed hydrolysis-condensable silane compound (a1) or (a2) may be partially or completely hydrolyzed (converted into a hydroxyl group) as long as it is not condensed.

The hydrolyzable condensable silane compound (a2) other than the hydrolyzable condensable silane compound (a1) includes, for example, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxy Silane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, trimethylmethoxysilane, trimethylethyl Oxysilane, vinyltri-dimethoxysilane, vinyltri-diethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane Silane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltrimethoxysilane Silane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethyl Oxysilane, 3-propenyloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl) group)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropylmethoxysilane, etc.

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

When the adhesive composition contains the (meth)acrylic resin (B) described later, the content of the siloxane compound (A) is preferably 0.01 with respect to 100 parts by mass of the (meth)acrylic resin (B). part by mass or more, more preferably not less than 0.05 part by mass, still more preferably not less than 0.1 part by mass, particularly preferably not less than 0.2 part by mass, preferably not more than 10 parts by mass, more preferably not more than 5 parts by mass, still more preferably 3 parts by mass Parts by mass or less, particularly preferably 1 part by mass or less, and most preferably 0.5 parts by mass or less, may be any combination of the lower limit and upper limit, for example, may be 0.01 to 10 parts by mass, more preferably 0.05 to 3 parts by mass, more preferably 0.1 to 1 part by mass, particularly preferably 0.2 to 0.5 part by mass. When the ratio of the siloxane compound (A) is in the above range, the durability and reworkability of the adhesive layer can be further improved.

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

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

The (meth)acrylic resin (B) preferably contains 50 mass % of the constituent units derived from the (meth)acrylic monomer with respect to 100 mass % of the total constituent units constituting the (meth)acrylic resin (B). % or more, more preferably 70 mass % or more, still more preferably 90 mass % or more of the polymer or copolymer. In addition, in this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid, and "(meth)acrylic acid ester" and "(meth)acryloyl group" similarly represent acrylic acid ester, respectively. Or methacrylate, acryl or methacryloyl.

The (meth)acrylic resin (B) may contain, for example, a structural unit derived from a polar functional group-containing (meth)acrylate, a structural unit derived from a (meth)acrylamide-based monomer, a benzene-derived structural unit Structural unit of vinyl monomer, Structural unit derived from vinyl monomer, Structural unit derived from monomer having plural (meth)acryloyl groups in molecule, Structural unit derived from alkyl acrylate, Structural unit derived from Structural unit of substituted alkyl acrylate, etc. These constituent units may be used alone or in combination of two or more.

Polar functional group-containing (meth)acrylates include, for example, hydroxyl-containing (meth)acrylates, epoxy-containing heterocyclic groups (meth)acrylates, substituted or unsubstituted amine-containing (meth)acrylates Meth)acrylate, carboxyl-containing (meth)acrylate, etc.

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

(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 aforementioned substituents may be the same or different)

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

In formula (b1) and formula (b2), X ¹ and X ² represent an optionally substituted methylene group. Examples of the substituent include halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom), alkyl groups (eg methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, tertiary C _1-10 alkyl groups such as butyl, pentyl, hexyl, preferably C _1-6 alkyl groups, more preferably C _1-3 alkyl groups), cycloalkyl groups (such as cyclopentyl, cyclohexyl, etc.), Aryl [eg phenyl, alkylphenyl (tolyl, xylyl, etc.)], aralkyl (eg benzyl, etc.), alkoxy (eg methoxy, ethoxy, etc. C _1-4 alkanes oxy), polyoxyalkylene (such as dioxyethylene, etc.), cycloalkoxy (such as cyclohexyloxy and other C _5-10 cycloalkoxy, etc.), aryloxy (such as phenoxy, etc.) , aralkoxy (such as benzyloxy, etc.), alkylthio (such as methylthio, ethylthio, etc. C _1-4 alkylthio, etc.), cycloalkylthio (such as cyclohexylthio, etc.), Arylthio (eg, phenylthio, etc.), aralkylthio (eg, benzylthio, etc.), acyl (eg, acetyl, etc.), nitro, cyano, and the like. Among these, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, etc. are preferable, and an alkyl group (for example, a methyl group, an ethyl group, etc.) is especially preferable.

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

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

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

Specific examples of the hydroxyl group-containing (meth)acrylate (b2) include 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, and 5-hydroxyheptyl (meth)acrylate. (meth)acrylate, 5-hydroxyoctyl (meth)acrylate, 5-hydroxynonyl (meth)acrylate, etc. (meth)acrylate 5-hydroxy C _5-12 alkyl ester; (meth)acrylate 6-hydroxyhexyl , 6-hydroxyheptyl (meth)acrylate, 6-hydroxyoctyl (meth)acrylate, 6-hydroxynonyl (meth)acrylate, 6-hydroxydecyl (meth)acrylate, etc. (meth)acrylic acid 6-Hydroxy C _6-13 alkyl ester; (meth)acrylate 7-hydroxyheptyl, (meth)acrylate 7-hydroxyoctyl, (meth)acrylate 7-hydroxynonyl, (meth)acrylate 7 -Hydroxydecyl, 7-hydroxyundecyl (meth)acrylate, etc. (meth)acrylate 7-hydroxy C _7-14 alkyl ester; (meth)acrylate 8-hydroxyoctyl, (meth)acrylate 8 -Hydroxynonyl ester, 8-hydroxydecyl (meth)acrylate, 8-hydroxyundecyl (meth)acrylate, 8-hydroxydodecyl (meth)acrylate, etc. (meth)acrylate 8-hydroxy C _{8 -15} Alkyl ester; 9-hydroxynonyl (meth)acrylate, 9-hydroxydecyl (meth)acrylate, 9-hydroxyundecyl (meth)acrylate, 9-hydroxydodecyl (meth)acrylate (Meth) 9-hydroxy C _9-16 alkyl esters such as (meth) acrylate, 9-hydroxy tridecyl (meth) acrylate; 10-hydroxy decyl (meth) acrylate, 10-hydroxy ten (meth) acrylate Monoester, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl (meth)acrylate, 10-hydroxytetradecyl (meth)acrylate, etc. (meth)acrylic acid 10-hydroxyl C _{10- 17} Alkyl ester; 11-hydroxyundecyl (meth)acrylate, 11-hydroxydodecyl (meth)acrylate, 11-hydroxytridecyl (meth)acrylate, 11-hydroxydecyl (meth)acrylate Tetraester, (meth)acrylic acid 11-hydroxypentadecyl (meth)acrylic acid 11-hydroxy C _11-18 alkyl esters; (meth)acrylic acid 12-hydroxydodecyl, (meth)acrylic acid 12- (Meth) 12-hydroxy C _12-19 alkyl esters such as hydroxytridecyl, 12-hydroxytetradecyl (meth)acrylate; 13-hydroxytridecyl (meth)acrylate, (meth)acrylic acid 13-Hydroxytetradecyl (meth)acrylate, 13-hydroxypentadecyl (meth)acrylate and other (meth)acrylate 13-hydroxy C _13-20 alkyl esters; (meth)acrylate 14-hydroxytetradecyl, (meth)acrylate ) 14-hydroxypentadecyl acrylate, etc. (meth) 14-hydroxyl C _14-21 alkyl esters; 15-hydroxy C _15-22 alkyl meth)acrylate, etc. Among these, from the viewpoint of durability, 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, (meth)acrylate are preferred. (meth)acrylates containing hydroxyl groups in which n is 5, such as 5-hydroxyoctyl (meth)acrylate and 5-hydroxynonyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate is particularly preferred.

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

The ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate represented by the aforementioned formula (b1) with respect to 100 parts by mass of the total structural units constituting the (meth)acrylic resin is preferably 1.5 to 5 parts by mass parts, more preferably 2 to 4.5 parts by mass, the ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate represented by the aforementioned formula (b2), preferably 0.1 to 2 parts by mass, more preferably 0.25 to 1 part by mass. Moreover, 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) ), as long as the above range is not particularly limited, preferably (b1)/(b2)=13/1 to 3/1, more preferably 11/1 to 3/1, and more preferably 9/1 to 4 /1, the best is 7/1 to 5/1. Within the above range, the durability of the adhesive layer can be further improved.

Examples of the heterocyclic group-containing (meth)acrylate include acryl molyfrin, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, and tetrahydrofuranmethyl (meth)acrylate. Esters, caprolactone-modified tetrahydrofuran methyl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran, etc. .

(Meth)acrylate containing a substituted or unsubstituted amino group, for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, (meth)acrylate base) dimethylaminopropyl acrylate, etc.

Carboxyl group-containing (meth)acrylates include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, carboxyalkyl (meth)acrylate (for example, (methyl) ) carboxyethyl acrylate, carboxypentyl (meth)acrylate) and the like. These carboxyl group-containing (meth)acrylates can be used alone or in combination of two or more. Moreover, it is preferable that the structural unit derived from the monomer which has an amine group is not contained substantially from a viewpoint of preventing the fall of the peelability of the separator which may be laminated|stacked on the adhesive layer. The term "substantially not contained" means less than 1.0 part by mass with respect to 100 parts by mass of the total structural units constituting the (meth)acrylic resin (B).

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

(Meth)acrylamide-based monomers include, for example, N-methylol acrylamide, N-(2-hydroxyethyl)acrylamide, N-(3-hydroxypropyl)acrylamide, N- (4-Hydroxybutyl) acrylamide, N-(5-hydroxypentyl) acrylamide, N-(6-hydroxyhexyl) acrylamide, N,N-dimethylacrylamide, N,N -Diethylacrylamide, N-isopropylacrylamide, N-(3-dimethylaminopropyl)acrylamide, N-(1,1-dimethyl-3-oxobutane) base) acrylamide, N-[2-(2-oxo-1-imidazolidinyl)ethyl] acrylamide, 2-acrylamido-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, etc. The durability of the adhesive layer can be further improved by containing a structural unit derived from a (meth)acrylamide-based monomer. In particular, among these, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, and the like.

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

Styrene-based monomers include, for example, styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, Alkylstyrenes such as butylstyrene, hexylstyrene, heptylstyrene, octylstyrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene; nitrostyrene Ethyl styrene; Acetyl styrene; Methoxy styrene; Divinyl benzene, etc.

Examples of vinyl monomers include vinyl acetate, vinyl propionate, vinyl valerate, vinyl 2-ethylhexanoate, vinyl laurate and other fatty acid vinyl esters; vinyl halides such as vinyl chloride and vinyl bromide; halogenated vinylidene such as vinylidene; nitrogen-containing aromatic vinyl such as vinylpyridine, vinylpyrrolidone, vinylcarbazole; conjugated diene monomers such as butadiene, isoprene, and chloroprene; acrylonitrile, methyl Unsaturated nitriles such as acrylonitrile, etc.

Monomers having a plurality of (meth)acryloyl groups in the molecule include, for example, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, ,9-Nanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate Propylene glycol di(meth)acrylate is equal to a monomer with 2 (meth)acryloyl groups in the molecule; trimethylolpropane tri(meth)acrylate is equal to 3 (meth)acryloyl groups in the molecule 's monomer.

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

Alkyl acrylate (b3) whose glass transition temperature (Tg) of the homopolymer does not reach 0°C, for example, ethyl acrylate, n- and isopropyl acrylate, n- and isobutyl acrylate, n-amyl acrylate, acrylic acid Carbon number of alkyl groups such as n- and iso-hexyl acrylate, n-heptyl acrylate, n- and iso-octyl acrylate, 2-ethylhexyl acrylate, n- and isononyl acrylate, n- and iso-decyl acrylate, n-dodecyl acrylate, etc. Linear or branched alkyl acrylate of about 2 to 12, etc. The alkyl acrylate (b3) may also be an alkyl acrylate (cycloalkyl acrylate) having an alicyclic structure. From the viewpoints of traceability (or flexibility or adhesion) to optical films, acrylic carbon The alkyl ester with 2 to 10 carbon atoms is preferred, the alkyl acrylate with 3 to 8 carbon atoms is more preferred, the alkyl acrylate with 4 to 6 carbon atoms is still more preferred, and n-butyl acrylate is particularly preferred. When n-butyl acrylate is used, the traceability can be improved, and it is advantageous for peeling resistance, for example. These alkyl acrylates (b3) may be used alone or in combination of two or more.

The Tg of the homopolymer is an alkyl acrylate (b4) above 0°C, such as methyl acrylate, cycloalkyl acrylate (such as cyclohexyl acrylate, isobornyl acrylate), stearyl acrylate, triacrylate Grade butyl ester, etc., especially methyl acrylate is preferred. When methyl acrylate is used, the strength can be improved, which is advantageous for, for example, cohesion failure. These alkyl acrylates (b4) may be used alone or in combination of two or more. In addition, for the Tg of the homopolymer of alkyl acrylate, for example, reference can be made to literature values such as POLYMER HANDBOOK (Wiley-Interscience).

In a preferred form, from the viewpoint of improving the durability of the adhesive layer, the (meth)acrylic resin (A) contains an alkyl acrylate (b3) derived from a homopolymer whose glass transition temperature is less than 0°C The structural unit of , and the structural unit of the alkyl acrylate (b4) derived from the glass transition temperature of a homopolymer is 0 degreeC or more. If an alkyl acrylate whose Tg of the homopolymer is less than 0°C and an alkyl acrylate whose Tg of the homopolymer is 0°C or higher are used in combination, both the coagulation failure resistance and the traceability (foaming resistance and resistance to foaming) can be achieved. releasability), and can improve the durability against dimensional changes of optical films such as polarizers.

The ratio of the constituent unit derived from the alkyl acrylate in the (meth)acrylic resin (B) relative to the constituent (meth)acrylic resin (B) is considered from the viewpoints of durability and reworkability of the adhesive layer. ) of the total constituent unit of 100 parts by mass, preferably more than 40 parts by mass, more preferably more than 50 parts by mass, more preferably more than 60 parts by mass, particularly preferably more than 70 parts by mass, and most preferably more than 80 parts by mass, Preferably it is 98 parts by mass or less, more preferably 95 parts by mass or less, and more preferably 90 parts by mass or less, and can also be any combination of these lower limit values and upper limit values, such as 50 to 98 parts by mass, Preferably it is 70-95 mass parts, More preferably, it is 80-90 mass parts.

The difference between the constituent unit of the homopolymer-derived alkyl acrylate (b3) having a glass transition temperature of less than 0°C and the constituent unit of the homopolymer-derived alkyl acrylate (b4) having a glass transition temperature of 0°C or higher Ratio (mass ratio), preferably (b3)/(b4)=20/80 to 95/5, more preferably 30/70 to 90/10, still more preferably 30/70 to 85/15, particularly good 30/70 to 70/30. Within the above range, durability can be further improved. The higher the ratio of the constituent unit derived from the alkyl acrylate (b3) having a glass transition temperature of less than 0°C, the higher the traceability. The greater the ratio of the constituent unit derived from the alkyl acrylate (b4) having a glass transition temperature of 0°C or higher, the higher the coagulation failure resistance.

Examples of the substituent-containing alkyl acrylate include alkyl acrylates in which a substituent (the hydrogen atom of the alkyl group is substituted with the substituent) is introduced into the alkyl group in the aforementioned alkyl acrylate. As such a substituent, an aryl group (a phenyl group, etc.), an aryloxy group (a phenoxy group, etc.), an alkoxy group (for example, a methoxy group, an ethoxy group, etc.) etc. are mentioned, for example. Examples of substituted alkyl acrylates include alkoxyalkyl acrylates (such as 2-methoxyethyl acrylate, ethoxymethyl acrylate, etc.), arylalkyl acrylates (such as benzyl acrylate, etc.) acrylic acid ester, etc.), aryloxyalkyl acrylate (eg, phenoxyethyl acrylate, etc.), aryloxy polyalkylene glycol monoacrylate, polyalkylene glycol monoacrylate, and the like. These substituent-containing alkyl acrylates may be used alone or in combination of two or more. By containing acrylic alkyl ester containing aromatic rings such as aryl group, benzyl group, aryloxy group, etc., the white spot of the polarizing plate can be improved during the durability test. Moreover, by containing an alkoxy group, an aryloxy group, etc., the antistatic property at the time of adding an antistatic agent to an adhesive bond layer can be improved. The alkylene of aryloxy polyalkylene glycol monoacrylate and polyalkylene glycol monoacrylate can be, for example, C _1-6 alkylene such as methylene, ethylidene, and propylidene (preferably From the viewpoint of the balance between durability and antistatic property of the adhesive layer formed by the adhesive composition, the repeating unit of the alkylene group is, for example, 1 to 7, preferably 1 to 5, 1 to 2 are particularly preferred. Specifically, for example, phenoxy di- to hepta C _1-3 alkylene glycol acrylates such as phenoxy diethylene glycol acrylate, and di- to hepta C ₁ monoacrylates such as diethylene glycol monoacrylate can be mentioned. _-3 alkylene glycol esters, etc. The substituent-containing alkyl acrylate used in the present invention is particularly preferably phenoxyethyl acrylate and phenoxydiethylene glycol acrylate from the viewpoint of the balance of durability, vitiligo resistance, and antistatic property. ester.

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

In order to improve the durability of the adhesive layer, the weight average molecular weight (Mw) of the (meth)acrylic resin (B) in terms of standard polystyrene obtained by gel permeation chromatography (GPC) is preferably 1 million or more. The lower limit value of Mw is preferably 1.1 million, still more preferably 1.2 million, and particularly preferably 1.3 million. In addition, the upper limit value of Mw is not particularly limited, but from the viewpoint of coatability when the adhesive composition is processed into a sheet shape (coated on a substrate), for example, it is preferably 2.5 million, more preferably 2.2 million, More preferably, it is 2 million. Mw can also be any combination of these upper limit values and lower limit values, such as 1 million to 2.5 million, more preferably 1.1 to 2.2 million, and still more preferably 1.3 to 2 million. Moreover, the molecular weight distribution represented 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, more preferably 4 to 6.

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

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

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

The glass transition temperature (Tg) of the (meth)acrylic resin (B) is, for example, -60 to 0°C, preferably -50 to -10°C, more preferably -50 to -20°C, and still more preferably -40 to -20°C, particularly preferably -40 to -25°C. If Tg is in the said range, it is favorable for the durability of an adhesive bond layer to improve. In addition, the glass transition temperature can be measured by 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 particularly, solution polymerization is preferred. The solution polymerization method can be, for example, the following method. The monomers and the organic solvent are mixed, a thermal polymerization initiator is added in a nitrogen atmosphere, and the temperature is about 40 to 90°C, preferably about 50 to 80°C, and stirred. 3 to 15 hours or so. In order to control the reaction, monomers or thermal polymerization initiators can also be added continuously or intermittently during the polymerization. The monomer and the thermal polymerization initiator may be added to the organic solvent.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like can be used. As a photopolymerization initiator, 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-propyl) ketone etc. are mentioned, for example. As the thermal polymerization initiator, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane- 1-Nitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile) , 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 2,2'-azobis(2-hydroxymethylpropionitrile) and other azo compounds; lauryl peroxide, Tertiary butyl hydroperoxide, benzyl peroxide, tertiary butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, peroxide Organic peroxides such as tertiary butyl neodecanoate, tertiary butyl peroxypivalate, (3,5,5-trimethylhexyl) peroxide; potassium persulfate, ammonium persulfate, Inorganic peroxides such as hydrogen peroxide, etc. In addition, a redox-based initiator or the like in which a peroxide and a reducing agent are used in combination can also be used.

The ratio of the polymerization initiator is about 0.001 to 5 parts by mass with respect to 100 parts by mass of the total amount of the monomers constituting the (meth)acrylic resin. The polymerization method of (meth)acrylic-type resin can also use the polymerization method by active energy rays (for example, an ultraviolet-ray etc.).

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

[1-3] Cross-linking agent (C)

The adhesive composition may contain a crosslinking agent (C). The crosslinking agent (C) reacts with reactive groups (eg, hydroxyl groups) in the (meth)acrylic resin (B). The crosslinking agent (C) forms a crosslinked structure with the (meth)acrylic resin, and forms a crosslinked structure favorable for durability and reworkability.

As the cross-linking agent (C), for example, conventional cross-linking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelates, peroxides, etc.) can be mentioned. From the viewpoints of durability, crosslinking speed, and the like of the adhesive layer, an isocyanate compound is preferred.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, and examples thereof include aliphatic isocyanate-based compounds (such as hexamethylene diisocyanate, etc.), alicyclic isocyanate-based compounds (such as isocyanato) phorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate), aromatic isocyanate compounds (such as tolyl diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate) , triphenylmethane triisocyanate) and so on. In addition, the crosslinking agent (C) may be an adduct (adduct body) of the polyol compound of the aforementioned isocyanate compound [for example, an adduct of glycerol, trimethylolpropane, etc.], a trimeric isocyanate compound, a condensed product. Urethane prepolymerization obtained by addition reaction of biuret type compound, polyether alcohol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. Derivatives of isocyanate compounds etc. The crosslinking agent (C) may be used alone or in combination of two or more. Among these, representative examples include aromatic isocyanate-based compounds (eg, tolyl diisocyanate, xylene diisocyanate), aliphatic isocyanate-based compounds (eg, hexamethylene diisocyanate), or polyvalent compounds of these. Adducts of alcohol compounds (eg, glycerol, trimethylolpropane), or trimeric isocyanates. If the cross-linking agent (C) is an adduct of aromatic isocyanate-based compounds and/or these polyol compounds, or trimeric isocyanates, it is beneficial to form the best cross-linking density (or cross-linking structure). ), so the durability of the adhesive layer can be improved. In particular, if it is an adduct of a tolyl diisocyanate compound and/or these polyol compounds, even when an adhesive layer is used for a transparent electrode, durability can be improved.

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, more preferably 0.1 part by mass or more, relative to 100 parts by mass of the (meth)acrylic resin (B), It is particularly preferably 0.2 parts by mass or more, most preferably 0.3 parts by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less, extremely It is preferably 1 part by mass or less, preferably 0.8 part by mass or less, and can be any combination of the lower limit and upper limit, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, more It is preferably 0.1 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, particularly preferably 0.2 to 1 part by mass, and most preferably 0.3 to 0.8 parts by mass. If it is more than the upper limit, it is favorable for the improvement of traceability (or peeling resistance), and if it is more than the lower limit, it is favorable for the improvement of agglomeration resistance (or foaming resistance) or reworkability.

[1-4]Silane compound (D)

The adhesive composition may contain a siloxane compound (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 vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxysilane Oxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-ethyl oxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyl trimethoxysilane, 1,3-bis(3'-trimethoxypropyl)urea, etc.

In addition, the silane compound (D) may be a polysiloxane oligomer type compound, and if the polysiloxane oligomer is represented by a combination of monomers, for example, 3-mercaptopropyl di- or trimethoxy Silane-tetramethoxysilane oligomer, 3-mercaptomethyldi- or trimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyldi- or triethoxysilane-tetramethoxysilane oligomer, 3 -Oligomers containing mercaptoalkyl groups such as mercaptomethyl di- or triethoxysilane-tetraethoxysilane oligomers; other substituents [3- glycidoxypropyl, (meth)acryloyloxypropyl, vinyl, amine, etc.] substituted oligomers.

[1-5] Antistatic agent

The adhesive composition may further contain an antistatic agent. By containing an antistatic agent, the antistatic property of an adhesive can be improved (for example, it is possible to suppress the inconvenience caused by static electricity generated when peeling a release film, a protective film, etc.). As the antistatic agent, for example, those conventionally used are mentioned, and an ionic antistatic agent is preferable. As a cationic component which comprises an ionic antistatic agent, an organic cation, an inorganic cation, etc. are mentioned, for example. Examples of organic cations include pyridinium cations, imidazolium cations, ammonium cations, pernium cations, phosphonium cations, and the like. 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, and an anion component containing a fluorine atom is preferred because of its excellent antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion (PF ₆ ⁻ ), bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ], bis(fluorosulfonyl) anion base) imide anion [(FSO ₂ ) ₂ N ^- ], tetrakis(pentafluorophenyl)borate anion [(C ₆ F ₅ ) ₄ B ^- ] and the like. These antistatic agents can be used alone or in combination of two or more. In particular, bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ^- ], bis(fluorosulfonyl) imide anion [(FSO ₂ ) ₂ N ^- ], tetrakis(pentafluoro) Phenyl)borate anion [(C ₆ F ₅ ) ₄ B ⁻ ] is preferred. From the viewpoint that the antistatic properties of the adhesive layer formed from the adhesive composition are excellent in stability over time, an ionic antistatic agent that is solid at room temperature is preferable.

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

Even if the adhesive composition of the present invention contains an antistatic agent, it exhibits good durability in a high temperature environment. Therefore, both good durability and antistatic properties can be achieved.

[1-6] Other ingredients

The adhesive composition may contain alone or two or more additives such as solvents, cross-linking catalysts, ultraviolet absorbers, weathering stabilizers, tackifiers, plasticizers, softeners, dyes, pigments, inorganic fillers, light-scattering microparticles, etc. . Moreover, if an ultraviolet-ray curable compound is mix|blended with an adhesive composition, and after forming an adhesive bond layer, it irradiates an ultraviolet-ray and hardens it, and a harder adhesive bond layer can be formed. The crosslinking catalyst includes, for example, hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, Amine compounds such as polyamine resin and melamine resin, etc.

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

In a preferred form, the adhesive composition of the present invention does not substantially contain a photopolymerization initiator and its decomposition products. This is because the photopolymerization initiator and its decomposition products in the adhesive composition may hinder the formation of an adhesive layer with excellent durability. Here, "substantially not contained" means 1.0 part by mass or less with respect to 100 parts by mass of the adhesive composition, preferably 0.1 part by mass or less, more preferably 0.01 part by mass or less, and still more preferably 0.001 part by mass Parts by mass or less, particularly 0 parts by mass, is the best.

[2] Composition and manufacturing method of adhesive layer and optical film to which the adhesive layer is adhered

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

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

Since the adhesive layer of the present invention and the optical film to which the adhesive layer is attached are formed of the above-mentioned adhesive composition, even if they are used (or laminated) on a transparent electrode layer such as ITO, they will not fail under severe durability conditions. Has excellent durability.

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

When laminating the adhesive layer 20 on the surface of the optical film 10, it is preferable to form a primer layer on the bonding surface of the optical film 10 and/or the bonding surface of the adhesive layer, or apply the aforementioned surface activation treatment ( For example, plasma treatment, corona treatment, etc.), in particular, corona treatment is preferably applied.

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

Between the optical film 10 and the adhesive layer 20, an antistatic layer may be additionally provided. The antistatic layer can use 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, polystyrene sulfonic acid, and polyaniline.

The optical film 1 with the adhesive layer may also contain a release film (release film) laminated on the outer surface of the adhesive layer. The separator is usually peeled off and removed when the adhesive layer 20 is used (eg, when laminated on a transparent electrode or a glass substrate). For example, the release film can be applied to the surface of the adhesive layer 20 of a film formed of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate. Silicon oxide treatment and other stripping processors.

For the optical film 1 with the adhesive layer, each component constituting the above-mentioned adhesive composition can be dissolved or dispersed in a solvent to form an adhesive composition containing a solvent, and then, it is coated on the surface of the optical film 10 and dried to obtain a solvent-containing adhesive composition. The adhesive layer 20 is formed, thereby producing. In addition, the optical film 1 with the adhesive layer can also be formed by forming the adhesive layer 20 on the release-treated surface of the release film in the same manner as described above, and laminating (transferring) the adhesive layer 20 on the surface of the optical film 10. be made of.

The thickness of the adhesive layer is usually 2 to 40 μm, and is preferably 5 to 30 μm, more preferably 10 to 10 μm, from the viewpoints of durability of the adhesive layer-attached optical film or reworkability of the adhesive layer-attached optical film. 25μm. If the thickness of an adhesive bond layer is below the said upper limit, reworkability will be favorable, and if it is more than the said lower limit, the traceability with respect to the dimensional change of an optical film will be favorable.

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

Viscose fraction can be used as an indicator of crosslinking density. Since the adhesive layer of the present invention has a predetermined crosslinking density, it exhibits a predetermined gel fraction. That is, the gel fraction of the adhesive layer of the present invention may be, for example, 70 to 90 mass %, preferably 75 to 90 mass %, more preferably 75 to 85 mass %. When the gel fraction is equal to or more than the lower limit value, the foaming resistance and reworkability of the adhesive layer are favorable, and when the gel fraction is equal to or less than the upper limit value, the peeling resistance of the adhesive layer is favorable. In addition, the gel fraction can be measured by the method described in the Example section.

The optical film with the adhesive layer of the present invention has a predetermined adhesive force and is excellent in reworkability. That is, the adhesive layer on the surface of the optical film with the adhesive layer that is not attached to the optical film is attached to a glass substrate, and the adhesive layer is stored at a temperature of 23°C and a relative humidity of 50% for 24 hours. The force, at a peeling speed of 300 mm/min, is 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 more than the lower limit value, the adhesiveness (or adhesiveness) is improved, and it is advantageous for peeling resistance and the like, and when the adhesive force is equal to or less than the upper limit value, the reworkability is advantageous. In addition, the adhesive force can be measured by the method described in an Example, for example.

[2-1] Optical film

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

[2-2] Polarizing plate

FIG. 2 and FIG. 3 are schematic cross-sectional views showing an example of the layer structure of the polarizing plate. The polarizing plate 10a shown in FIG. 2 is a single-sided protective polarizing plate on which the first resin film 3 is laminated (or laminated) on a surface area of the polarizing plate 2, and the polarizing plate 10b shown in FIG. 3 is attached to the polarizing plate 2. On the other surface of the sheet 2, a double-sided protective polarizer of the second resin film 4 is laminated (or laminated and laminated). The first and second resin films 3 and 4 can be attached to the polarizer 2 through an adhesive layer or an adhesive layer (not shown). In addition, the polarizing plates 10a and 10b may contain other films or layers other than the first and second resin films 3 and 4 .

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

The polyvinyl alcohol-based resin can be obtained by saponifying the polyvinyl acetate-based resin. The polyvinyl acetate-based resins include, for example, polyvinyl acetate which is a vinyl acetate homopolymer, and monomers copolymerizable with vinyl acetate (for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids) , Copolymers of (meth)acrylamides with ammonium groups, etc.) and vinyl acetate, etc.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 to 100 mol %, preferably 98 mol % or more. The polyvinyl alcohol-based resin may also be modified, for example, polyvinyl formaldehyde or polyvinyl acetal modified with aldehydes. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000. In addition, the average degree of polymerization of a polyvinyl alcohol-type resin can be calculated|required based on JISK6726.

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

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

The polarizer 2 formed by adsorbing and aligning a dichroic pigment on a polyvinyl alcohol-based resin film can be obtained by the following method: using a separate film of the polyvinyl alcohol-based resin film as an original film, and applying a single film to the film. A method (method (1)) of axial stretching treatment and dyeing treatment of a dichroic dye, furthermore, a coating liquid (aqueous solution, etc.) containing a polyvinyl alcohol-based resin is coated on a base film and dried to obtain a polyvinyl alcohol-based resin. After the base film of the vinyl alcohol-based resin layer is uniaxially stretched, the stretched polyvinyl alcohol-based resin layer is dyed with a dichroic dye, and then the base film is stretched. A method of peeling and removing (method (2)). As the base film, a film composed of a thermoplastic resin and the same thermoplastic resin that can constitute the first and second resin films 3 and 4 described later can be used, and preferably a polyester-based resin such as polyethylene terephthalate, Polycarbonate-based resins, cellulose-based resins such as polyacetyl cellulose, cyclic polyolefin-based resins such as norbornene-based resins, and films composed of polystyrene-based resins. According to the above-mentioned method (2), the production of the polarizer 2 of the thin film becomes easy, for example, the production of the polarizer 2 having a thickness of 7 μm or less can be easily performed.

The first and second resin films 3 and 4 are each independently a resin film having translucency. The first and second resin films 3 and 4 are preferably optically transparent thermoplastic resins, for example, chain polyolefin-based resins (such as polyethylene-based resins, polypropylene-based resins, etc.) Polyolefin-based resins such as polyolefin-based resins (eg, norbornene-based resins, etc.); cellulose-based resins (eg, cellulose ester-based resins, etc.); polyester-based resins (eg, polyethylene terephthalate, polyethylene naphthalate, etc.) ethylene formate, polybutylene terephthalate, etc.); polycarbonate resins (such as 2,2-bis(4-hydroxyphenyl)propane and other polycarbonates derived from bisphenol, etc.); (methyl ) acrylic resins; polystyrene resins; polyether ether ketone resins; polysilicon resins, or films composed of their mixtures, copolymers, and the like. Among these, the first and second resin films 3 and 4 are preferably made of cyclic polyolefin-based resins, polycarbonate-based resins, cellulose-based resins, polyester-based resins, and (meth)acrylic-based resins, respectively. The film made of resin or the like is particularly preferably a film made of a cellulose-based resin, a cyclic polyolefin-based resin, or the like.

The chain polyolefin-based resin includes, for example, a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, a copolymer of two or more chain olefins, and the like.

Cyclic polyolefin-based resins include, for example, cyclic polyolefins containing norbornene or tetracyclododecene (alias: dimethanooctahydronaphthalene) or derivatives thereof as a polymer unit. Generic term for resin. Cyclic polyolefin resins include, for example, ring-opened (co)polymers of cyclic olefins and their hydrogenated products, addition polymers of cyclic olefins, cyclic olefins and chain olefins such as ethylene and propylene, or those having vinyl groups. Copolymers of aromatic compounds, and modified (co)polymers modified with unsaturated carboxylic acids or derivatives thereof. Among these, the cyclic olefin is preferably a norbornene-based resin using a norbornene-based monomer such as norbornene and a polycyclic norbornene-based monomer.

The fiber-based resin is preferably a cellulose ester-based resin, that is, a partially or completely esterified product of cellulose, and examples thereof include cellulose acetate, propionate, butyrate, and mixed esters of these. Among these, triacetate cellulose, diacetate cellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like are preferred.

The polyester-based resin is a resin other than the above-mentioned cellulose ester-based resin having an ester bond, and is generally composed of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. Polyester-based resins include, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene terephthalate, and polyethylene naphthalate. Propylene formate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate, etc.

The polycarbonate resin is a polyester formed of carbonic acid and diol or bisphenol. Among these, from the viewpoint of heat resistance, weather resistance, and acid resistance, an aromatic polycarbonate having a diphenylalkane in a molecular chain is preferred. Examples of polycarbonates include 2,2-bis(4-hydroxyphenyl)propane (alias bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyl) phenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane, 1,1-bis(4-hydroxyphenyl)ethane, etc., polycarbonates derived from bisphenols, and the like.

The (meth)acrylic resin that can constitute the first and second resin films 3 and 4 may be a polymer mainly composed of a structural unit derived from methacrylate (for example, containing 50% by mass or more of the structural unit), A copolymer obtained by copolymerizing the constituent unit and other copolymerization components is preferable. The (meth)acrylic resin may contain two or more structural units derived from methacrylates. Examples of the methacrylate include C ₁ to C ₄ alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

As a copolymerization component which can be copolymerized with methacrylate, acrylate is mentioned, for example. The acrylate is preferably a C ₁ to C ₈ alkyl ester of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Specific examples of other copolymerization components include unsaturated acids such as (meth)acrylic acid; aromatic vinyl compounds such as styrene, halogenated styrene, α-methylstyrene, and vinyltoluene; (meth)acrylonitrile Etc. vinyl cyanide compounds; unsaturated acid anhydrides such as maleic anhydride, pyrocitric anhydride; unsaturated imines such as phenylmaleimide, cyclohexylmaleimide, etc. are equivalent to having a polymeric carbon-carbon double bond in the molecule Compounds other than acrylates. A compound having two or more polymerizable carbon-carbon double bonds in the molecule can also be used as a copolymerization component. A copolymerization component can be used individually or in combination of 2 or more types.

From the viewpoint of improving the durability of the film, the (meth)acrylic resin may have a ring structure in the polymer main chain. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic imide structure, and a lactone ring structure. Specific examples of the cyclic acid anhydride structure include, for example, a glutaric anhydride structure, a succinic anhydride structure, and the like; As a specific example of a ring structure, a butyrolactone ring structure, a valerolactone ring structure, etc. are mentioned, for example.

The (meth)acrylic resin may contain acrylic rubber particles from the viewpoints of film formability of the film, impact resistance of the film, and the like. The so-called acrylic rubber particles refer to particles having an elastic polymer mainly composed of acrylic ester as an essential component. Multilayer constructor. Examples of the elastic polymer include, for example, a cross-linked elastic copolymer containing an alkyl acrylate as a main component and copolymerized with other vinyl monomers and cross-linkable monomers that can be copolymerized therewith. Examples of the alkyl acrylate as the main component of the elastic polymer include C ₁ to C ₈ alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The number of carbon atoms in the alkyl group is preferably 4 or more.

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

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. When the content of the acrylic rubber particles is too large, the surface hardness of the film is lowered, and when the film is subjected to surface treatment, the solvent resistance to the organic solvent in the surface treatment agent is lowered. Therefore, the content of the acrylic rubber particles is usually 80 parts by mass or less, preferably 60 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin.

The first and second resin films 3 and 4 may contain general additives 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. As an ultraviolet absorber, a salicylate compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyano (meth)acrylate compound, a nickel salt, etc. are mentioned, for example.

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

In addition, the first resin film 3 and/or the second resin film 4 may be provided with a hard shell layer, an anti-glare layer, an anti-reflection layer, a light diffusing layer, Antistatic layer, antifouling layer, conductive layer and other surface treatment layers (coating layers). The thickness of the first resin film 3 and the second resin film 4 is generally 1 to 150 μm, preferably 5 to 100 μm, more preferably 5 to 60 μm, and more preferably 50 μm or less (for example, 1 to 40 μm), It is preferably 30 μm or less (for example, 5 to 25 μm).

In particular, for polarizing plates that tend to be small and medium-sized, such as smartphones and tablet terminals, thin films with a thickness of 30 μm or less are often used as the first resin film 3 and/or the second resin film 4 due to the requirement of thinning. The polarizing plate-based polarizer 2 has a weaker restraining force against the shrinkage force, and the durability tends to be insufficient. Even when such a polarizing plate is used as the optical film 10, the optical film 1 with the adhesive layer of the present invention has good durability.

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

Examples of the water-based adhesive include conventional water-based adhesives (for example, adhesives composed of a polyvinyl alcohol-based resin aqueous solution, water-based two-component urethane-based emulsion adhesives, aldehyde compounds, epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, amine compounds, cross-linking agents such as polyvalent metal salts, etc.). Among these, a water-based adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin can be preferably used. Moreover, when an aqueous adhesive agent is used, after bonding the polarizer 2 and the 1st, 2nd resin films 3, 4, it is preferable to implement the drying process for removing the water contained in the aqueous adhesive agent. After the drying step, for example, a curing step of curing at a temperature of about 20 to 45° C. may be provided.

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

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

The method of laminating the polarizer 2 and the first and second resin films 3 and 4 includes, for example, applying a surface activation treatment such as saponification treatment, corona treatment, plasma treatment, etc. to the lamination surface of at least either side of these method etc. When laminating resin films on both sides of the polarizer 2 , the adhesives used for laminating these resin films may be the same type of adhesive or different types of adhesives.

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

The protective film is usually composed of a base film and an adhesive layer laminated thereon. The base film can be made of thermoplastic resins such as polyolefin-based resins such as polyethylene-based resins, polypropylene-based resins, etc.; polyester-based resins such as polyethylene terephthalate or polyethylene naphthalate; polycarbonate-based resins; (meth)acrylic resin or the like.

[2-3] Phase difference plate

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

The so-called zero retardation film refers to a film whose in-plane retardation value _Re and thickness direction retardation value R _th are both -15 to 15 nm. The retardation film can be used in an IPS mode liquid crystal display device. The in-plane retardation value _Re and the thickness direction retardation value R _th are preferably both -10 to 10 nm, more preferably both -5 to 5 nm. The in-plane retardation value _Re and the thickness-direction retardation value R _th referred to here refer to values at a wavelength of 590 nm.

The in-plane retardation value _Re and the thickness direction retardation value R _th are respectively defined as the following formulas: _Re =(n _{x -ny} )×d

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

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

In addition, a film that exhibits optical anisotropy by coating and alignment of a liquid crystal compound, and a film that exhibits optical anisotropy by coating an inorganic layered compound can also be used as a retardation film. Such retardation films include those called temperature-compensated retardation films, as well as rod-shaped liquid crystal tilt-oriented films sold under the trade name of "NH Film" by JX Nippon Mining Energy Co., Ltd., and films made of Fuji Film (stocks). ) a disc-shaped liquid crystal tilt-aligned film sold under the trade name of "WV Film", a fully biaxially oriented film sold under the trade name of "VAC Film" by Sumitomo Chemical Co., Ltd., and similarly by Sumitomo Chemical Co., Ltd. ( Co., Ltd.) is a biaxially oriented film sold under the trade name of "new VAC Film". Moreover, the resin film laminated on at least one side of the retardation film may be, for example, the above-mentioned protective film.

[3] Optical laminate

The present invention is an optical laminate including the optical film containing the above-mentioned adhesive layer. The optical layered product is preferably a base material on the adhesive layer side of the optical film with the pressure-sensitive adhesive layer and the optical film with the pressure-sensitive adhesive layer laminated.

The base material is a conventional base material, for example, a glass substrate, a plastic film, an organic conductive film, a metal layer, an overcoat resin layer, and the like. In the optical laminate of the present invention, since the adhesive layer is formed of the above-mentioned adhesive composition, even if a metal layer such as a transparent electrode layer such as ITO or a metal layer such as a metal mesh (metal wiring layer) is used as the base material, the adhesive layer can be used under severe durability conditions. It also has excellent durability.

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

The optical laminate 5 shown in FIG. 4 is formed by laminating the electrode layer 30 on the substrate 40 and on the surface of the adhesive layer of the optical film 1a with the adhesive layer (or the polarizer 10a with the adhesive layer). optical laminates. The above-mentioned optical film 1a with the adhesive layer is the one where the adhesive layer 20 is layered on the area of the polarizer 2 side of the polarizing plate 10a.

The optical laminate 6 shown in FIG. 5 is formed by laminating the electrode layer 30 laminated on the substrate 40 and the adhesive layer of the optical film 1b with the adhesive layer (or the polarizing plate 10b with the adhesive layer) laminated above. faceted optical laminates. The optical film 1b with the adhesive layer is an optical film with the adhesive layer 20 on the area of the second resin film 4 side of the polarizing plate 10b.

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

As a method of forming the electrode layer 30 on the substrate 40, for example, a sputtering method can be mentioned. The substrate 40 may be a transparent substrate constituting the liquid crystal cells included in the touch input element, preferably a glass substrate. As the material of the glass substrate, soda lime glass, low alkali glass, alkali free glass, etc. 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.

As the electrode layer 30, a transparent electrode layer, a metal layer, etc. are mentioned, for example.

The transparent electrode layer includes, for example, a layer composed of tin oxide, indium oxide, zinc oxide, potassium oxide, aluminum oxide, and a mixture thereof. From the viewpoint of electrical conductivity and visible light transmittance, ITO is preferable.

The metal layer includes, for example, a layer containing at least one metal element selected from the group consisting of aluminum, copper, silver, iron, tin, zinc, nickel, molybdenum, chromium, tungsten, lead, and alloys containing two or more of these metals. Among these, from the viewpoint of electrical conductivity, a metal layer containing at least one metal element selected from aluminum, copper, silver, and gold is preferred, and a metal layer containing at least one metal element selected from aluminum, copper, and silver is more preferred. metal layer.

In addition, the metal layer may be a metal mesh in which a metal wiring layer of thin wires is arranged on a substrate, or a layer in which metal nanoparticles and metal nanowires are added to an adhesive.

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

The electrode layer is preferably a transparent electrode layer and a metal layer formed by sputtering, inkjet printing or gravure printing, more preferably a transparent electrode layer and a metal layer formed by 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. Furthermore, when the electrode layer 30 is a metal wiring layer (eg, a metal mesh), the line width of the metal wiring is usually 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and usually 0.5 μm or more.

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

The optical laminate 8 shown in FIG. 7 is formed on the surface of the electrode layer 30 laminated on the substrate 40 (the surface opposite to the substrate 40 ), and then the laminated resin layer 50 is laminated on the aforementioned adhesive The optical laminate on the surface of the adhesive layer 20 of the optical film 1 of the layer. The resin which forms the resin layer 50, the resin etc. which comprise the 1st or 2nd resin film which were exemplified above are mentioned, for example.

The optical laminate 9 shown in FIG. 8 is mounted on a substrate 40, and a plurality of electrode layers 30 are laminated at predetermined intervals in the longitudinal and width directions, and between the plurality of electrode layers 30 (or gaps) and the electrode layers 30 It is the same as the optical layered body 7 except that the resin layer 50 is formed (or laminated) on the surface (the surface opposite to the substrate 40 ). In the form of the optical laminate 9 (the form in which the electrode layer 30 is patterned into a predetermined shape), the metal layer 30 may also be a metal wiring layer ( That is, the electrode layer).

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

After the optical film (1, 1a, 1b) with the adhesive layer is attached to the substrate 40 (glass substrate, transparent substrate, etc.) or the electrode layer 30 to form an optical laminate, if there is any defect, the adhesive must be attached. The optical film of the adhesive layer is peeled off from the substrate 40 or the electrode layer 30 , and another optical film with the adhesive layer is attached to the substrate 40 or the electrode layer 30 again, which is a so-called reprocessing operation. The adhesive layer-attached optical film 1 of the present invention is not prone to fogging or residual glue on the surface of the glass substrate or electrode layer (eg, transparent electrodes such as ITO) after peeling, and is excellent in reworkability.

[4] Liquid crystal display device

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

The liquid crystal display device may also be a touch input type liquid crystal display device having a touch panel function. A touch input type liquid crystal display device is provided with a touch input element including liquid crystal cells, and a backplane. The structure of the touch panel can be a well-known method (such as an out cell type, an on cell type, an in cell type, etc.), and the operation method of the touch panel can be a well-known method, such as a resistive film method, a capacitive method ( Surface capacitive, projected capacitive), etc. The optical film with the adhesive layer of the present invention can be arranged on the visual recognition side of the touch input element (liquid crystal cell), on the back plate side, or on both sides. The driving method of the liquid crystal cell may be any conventionally known method such as a TN method, a VA method, an IPS method, a multi-domain arrangement method, and an OCB method. Moreover, in the said liquid crystal display device, the board|substrate 40 which has an optical laminated body may be a board|substrate (typically a glass substrate) contained in the said liquid crystal cell.

[5] Siloxane compound for adhesive (A)

The present invention also includes the siloxane compound (A) for adhesives. The aforementioned siloxane compound (A) for adhesives is the same as the aforementioned siloxane compound (A), the ratio of the alkoxy group of the hydrolyzed condensate (a), the weight average molecular weight of the hydrolyzed condensate (a) and its The preferred ranges are also the same. Moreover, the adhesive layer using the siloxane compound (A) for adhesives is not specifically limited, For example, the adhesive layer which consists of the adhesive composition as described in said [1] is mentioned preferably.

[Example]

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these examples. Hereinafter, the usage amount, the content and the % are all based on the quality unless otherwise specified.

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

In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirrer, a solution obtained by mixing the monomers with the composition shown in Table 1 (values in Table 1 are parts by mass) and 81.8 parts of ethyl acetate was charged. After replacing the air in the reaction container with nitrogen, the internal temperature was adjusted to 60°C. Then, a solution obtained by dissolving 0.12 parts of azobisisobutyronitrile in 10 parts of ethyl acetate was added. After keeping at the same temperature for 1 hour, keeping the inner temperature at 54 to 56°C, at an addition rate of 17.3 parts/Hr, ethyl acetate was continuously added to the reaction vessel so that the concentration of the degree of polymerization was approximately 35%. . After 12 hours passed from the start of the addition of ethyl acetate, the internal temperature was kept at 54 to 56° C., and then ethyl acetate was further added so that the concentration of the polymer was adjusted to 20% to obtain a (meth)acrylate resin. (B-1) in ethyl acetate. The weight average molecular weight Mw of the obtained (meth)acrylate resin (B-1) was 1.38 million, and the ratio (Mw/Mn) of the weight average molecular weight Mw to the number average molecular weight Mn was 4.8.

<Production Example 2: Production of (meth)acrylic resin (B-2) for adhesives>

An ethyl acetate solution (resin concentration: 20%) of (meth)acrylate-based resin (B-2) was prepared in the same manner as in Production Example 1, except that the composition of the monomers was the composition shown in Table 1. The weight average molecular weight Mw of the obtained (meth)acrylate 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 in the following manner. In a GPC apparatus, four "TSKgel XL" manufactured by Tosho Co., Ltd. and "Shodex GPC" manufactured by Showa Denko Co., Ltd. were used. A total of 5 pieces of KF-802" were connected in series as a column, and tetrahydrofuran was used as the eluent. The sample concentration was 5 mg/mL, the sample introduction volume was 100 μL, the temperature was 40 °C, and the flow rate was 1 mL/min. It is measured by standard polystyrene conversion. The conditions for obtaining the flow rate curve of GPC are also the same as above.

The glass transition temperature Tg was measured using a differential scanning calorimeter (DSC) "EXSTAR DSC6000" manufactured by SII Nanotechnology Co., Ltd. in a nitrogen environment with a temperature range of -80 to 50°C and a temperature increase rate of 10°C/min. Determination.

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

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

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

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

HEA: 2-hydroxyethyl acrylate

5HPA: 5-hydroxypentyl acrylate

PEA: phenoxyethyl acrylate

AA: Acrylic

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

In a reaction container equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, 326 parts of 1,6-bistrimethoxysilylhexane and 97.2 parts of methanol were charged. After replacing the air in the reaction container with nitrogen, the internal temperature was adjusted to 25°C. Then, the mixed solution which mixed 0.6 part of 1 normal hydrochloric acid aqueous solution, 10.2 parts of water, and 10.2 parts of methanol was added to the reaction container. After stirring the resulting 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 obtained mixture, and the mixture was refluxed for 2 hours. The solvent was distilled off from the obtained mixture to obtain a siloxane compound (A-1).

The weight average molecular weight of the obtained siloxane compound (A-1) was 1300. Moreover, according to the amount of water added, it was confirmed by ¹ H-NMR that 20% of the alkoxy groups were hydrolyzed. That is, the content of the alkoxy groups contained in the siloxane compound (A-1) is 100 mol % of the total amount of the alkoxy groups contained in the 1,6-bistrimethoxysilylhexane. 80 mol%.

<Production Example 4: Production Method of Siloxane Compound A-2>

In the reaction container provided with a cooling pipe, a thermometer, and a stirrer, 326 parts of 1,6-bistrimethoxysilylhexane and 97.2 parts of methanol were charged. After replacing the air in the reaction container with nitrogen, the internal temperature was adjusted to 25°C. Then, the mixed solution which mixed 0.6 part of 1 normal hydrochloric acid aqueous solution, 7.5 parts of water, and 10.2 parts of methanol was added to the reaction container. After stirring the resulting 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 obtained mixture, and the mixture was refluxed for 2 hours. The solvent was distilled off from the obtained mixture to obtain a siloxane compound (A-2).

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

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

(1) Preparation of adhesive composition

In the ethyl acetate solution (resin concentration: 20%) of the (meth)acrylate resin obtained in the above production example, the amount (parts by mass) of silicon shown in Table 2 was mixed with respect to 100 parts of the solid content of the solution. The oxane compound (A), the crosslinking agent (C), and the antistatic agent (E) in Examples 4, 7 and 8, and then, ethyl acetate was added so that the solid content concentration was 14% to obtain an adhesive composition. The compounding amount of each compounding ingredient shown in Table 2, when the commodity used contains a solvent, etc., is the mass fraction of the active ingredient contained therein.

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

(Siloxane compound (A))

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

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

A-3: Shin-Etsu Chemical Co., Ltd., trade name "X-12-967C" (trimethoxysilylpropyl succinic anhydride)

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

A-5: KBM403 (3-glycidoxypropyltrimethoxysilane)

(Crosslinker (C))

C-1: Toso Co., Ltd., trade name "Coronate L" (ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid content concentration 75%))

(Antistatic Agent (E))

E-1: N-decylpyridinebis(fluorosulfonyl)imide.

(2) Production of adhesive layer

Using a spreader, each adhesive composition prepared in the above (1) was applied to a release film composed of a polyethylene terephthalate film [made of The release-treated surface obtained from Lintec Co., Ltd. under the trade name "PLR-382051"] was dried at 100° C. for 1 minute to form an adhesive layer (adhesive sheet).

(3) Fabrication of Optical Film (P-1) with Adhesive Layer

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

On one side of the obtained polarizer, a transparent protective film composed of a 25 μm-thick triacetyl cellulose film (product made by Konica Minolta Opto Co., Ltd.) was pasted through an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin. name "KCUA"]. Next, on the opposite side of the polarizer to the triacetyl cellulose film, a zero-phase cyclic polyolefin-based resin with a thickness of 23 μm was pasted through an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin. Differential film [trade name "ZEONOR", manufactured by ZEON Co., Ltd., Japan], is made into a polarizing plate. Next, the surface on the opposite side of the surface in contact with the polarizer of the zero retardation film is subjected to corona discharge treatment for improving adhesion, and is then bonded to the adhesive produced by the above (2) by a bonding machine. The surface of the adhesive layer opposite to the release film (adhesive layer) was cured at a temperature of 23° C. and a relative humidity of 65% for 7 days to obtain an optical film (P-1) with an adhesive layer.

(4) Durability evaluation of optical film with adhesive layer

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

The following durability test was performed about the obtained optical laminated body.

[Durability test]

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

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

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

‧The 1000-cycle thermal shock (HS) test (glass substrate) was repeated with the operation of holding for 30 minutes in a drying condition at a temperature of 85°C and then holding it for 30 minutes in a drying condition at -40°C as one cycle.

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

5: There is no appearance change such as floating, peeling, foaming, etc.

4: Appearance changes such as floating, peeling, foaming, etc. are almost not seen

3: Slight appearance changes such as floating, peeling, foaming, etc. can be confirmed

2: obvious changes in appearance such as floating, peeling, foaming, etc.

1: Remarkably confirmed appearance changes such as floating, peeling, and foaming

Moreover, durability is favorable when it is 3 or more.

(5) Evaluation of the adhesive force of the optical film with the adhesive layer

The optical film (P-1) with the adhesive layer produced in the above (3) was cut into a test piece having a size of 25 mm×150 mm. The separator was peeled off from the test piece, and its adhesive layer was attached to the glass substrate. The obtained test piece attached to the glass substrate (optical film attached to the adhesive layer attached to the glass substrate) was pressed in an oven at a temperature of 50° C. and a pressure of 5 kg/cm ² (490.3 kPa) for 20 minutes. After storing for 24 hours in an environment with a temperature of 23° C. and a relative humidity of 50%, the optical film was peeled from the test piece together with the adhesive layer in the 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, reworkability is excellent, and when it is 0.5 N or more, peeling is unlikely to occur when an impact is received from the end of the polarizing plate.

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

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

[Gel fraction of adhesive tablet]

The method for evaluating the gel fraction of the adhesive sheet of the present invention is disclosed below. The greater the gel fraction, the more cross-linking reaction in the adhesive, which can be used as a measure of cross-linking density. The gel fraction is a value measured according to the following (a) to (d).

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

(b) The laminate obtained in the above (a) was weighed, and its mass was designated as Ws, and then it was folded four times so as to wrap the adhesive sheet and fixed with a stapler, and then weighed, and its mass was designated as Wb.

(c) The net fixed with the stapler in the above (b) was placed in a glass container, and 60 mL of ethyl acetate was added for immersion, and then the glass container was stored at room temperature for 3 days.

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

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

The optical films with adhesive layers obtained in Examples 1 to 9 showed good durability even under severe durability conditions. Shows good durability even when used on ITO substrates. Moreover, it also has favorable reworkability, and both durability and reworkability can be achieved.

Since the figures in this case are only illustrations, they are not representative figures of this case. Therefore, there is no designated representative map in this case.

Claims (14)

An adhesive composition containing a siloxane compound (A), wherein the siloxane compound (A) is a hydrolytic condensate (a) of a hydrolytically condensable silane compound represented by the following formula (a1); The total amount of the alkoxy groups contained in the hydrolyzable condensable silane compound (a1) is 100 mol %, and the content of the alkoxy groups contained in the siloxane compound (A) is 60 to 95 mol %;

In the formula, B represents an alkanediyl having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH ₂ - constituting the aforementioned alkanediyl and the aforementioned alicyclic hydrocarbon group can be -O- or -CO- substituted, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms. Alkyl or alkoxy with 1 to 5 carbons. The adhesive composition as described in claim 1, wherein the weight-average molecular weight of the siloxane compound (A) is 600 to 4,000 in terms of polystyrene. The adhesive composition described in claim 1 or 2 further contains a (meth)acrylic resin (B) and a crosslinking agent (C). The adhesive composition according to claim 3, wherein the ratio of the siloxane compound (A) is 0.01 to 10 parts by mass relative to 100 parts by mass of the (meth)acrylic resin (B). The adhesive composition according to claim 3, wherein the (meth)acrylic resin (B) contains an alkyl acrylate (b1) derived from a monomer having a glass transition temperature of less than 0°C The structural unit and the structural unit derived from the acrylic acid alkyl ester (b2) whose glass transition temperature of a monomer is 0 degreeC or more. The adhesive composition according to claim 3, wherein the ratio of the constituent units derived from the carboxyl group-containing (meth)acrylate contained in the (meth)acrylic resin (B) relative to the constituent The total structural unit of the (meth)acrylic resin (B) is 100 parts by mass, which is 1.0 part by mass or less. The adhesive composition according to claim 3, wherein the weight average molecular weight of the (meth)acrylic resin (B) is 1,000,000 to 2,500,000 in terms of polystyrene. The adhesive composition according to claim 3, wherein the crosslinking agent (C) is an isocyanate-based compound. The adhesive composition according to claim 3, wherein the ratio of the crosslinking agent (C) is 0.01 to 10 parts by mass relative to 100 parts by mass of the (meth)acrylic resin (B). An adhesive layer is composed of the adhesive composition described in any one of items 1 to 9 in the scope of the application. An optical film with an adhesive layer, which is obtained by laminating the adhesive layer described in claim 10 on at least one side of the optical film. The optical film with an adhesive layer as described in claim 11, wherein the optical film with an adhesive layer is not bonded to the optical film The adhesive layer on the top surface is attached to the glass substrate, and the adhesive force after storage for 24 hours under the conditions of temperature 23°C and relative humidity 50% is 0.5 to 10N/25mm at a peeling speed of 300mm/min. An optical laminate, which is an optical film comprising the adhesive layer described in claim 11 or 12. A siloxane compound (A) for adhesives, which is a hydrolysis condensate (a) of a hydrolysis condensable silane compound represented by the following formula (a1); The total amount of radicals is 100 mol %, and the content of alkoxy groups contained in the siloxane compound (A) is 60 to 95 mol %;

In the formula, B represents an alkanediyl group with 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group with a carbon number of 3 to 20, and -CH ₂ - constituting the aforementioned alkanediyl group and the aforementioned alicyclic hydrocarbon group can be replaced by -O- Or -CO-substituted, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms or Alkoxy with 1 to 5 carbon atoms.

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