TWI781113B - Pressure-sensitive adhesive composition - Google Patents

Abstract

A pressure-sensitive adhesive composition comprises a (meth)acrylic resin (A), a crosslinking agent (B) and a silane compound (C), wherein the (meth)acrylic resin (A) contains a structural unit derived from an acetoacetyl group-containing (meth)acrylate (a1) and a structural unit derived from a hydroxy group-containing (meth)acrylate (a2), and the mass ratio (a2) / (a1) of the structural unit is 0.5 to 5.

Description

adhesive composition

This patent application is based on Japanese patent application No. 2016-186152 (filing date: September 23, 2016) to claim priority under the Paris Convention, and this Japanese patent application is referred to in this specification and its entire content is quoted in this specification .

The present invention relates to an adhesive composition useful as an optical member usable in a liquid crystal display device, an adhesive layer comprising the adhesive composition, an optical film and an optical laminate including an adhesive layer comprising the adhesive layer Body, and adhesive composition (meth) acrylic resin.

The optical film represented by the polarizing plate formed by laminating a transparent resin film on one side or both sides of the polarizer is widely used as an optical component of image display devices such as liquid crystal display devices and organic EL display devices. An optical film such as a polarizing plate is often used by being attached to other components (such as a liquid crystal cell in a liquid crystal display device, etc.) via an adhesive layer (see Patent Document 1). Therefore, as an optical film, the optical film with the adhesive layer which preliminarily provided the adhesive layer on the one surface is known.

[Prior Art Literature] [Patent Document]

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

In recent years, image display devices such as liquid crystal display devices and organic EL display devices have been developed for use in portable devices represented by smart phones and tablet terminals, and in-vehicle devices represented by car navigation systems. In such an application, it may be exposed to a harsher environment than the conventional indoor TV application, so improving the durability of the device is a problem.

Similar durability is required for an optical film constituting an adhesive layer of an image display device or the like. That is to say, the adhesive layer assembled in the image display device, etc. may be placed in a high temperature or high temperature and high humidity environment, or placed in an environment with repeated high temperature and low temperature, and the optical film system for the adhesive layer requires Under these circumstances, defects such as floating and peeling of the interface between the adhesive layer and the optical member to which it is bonded, and foaming of the adhesive layer can be suppressed, and optical characteristics are also required not to deteriorate. Especially when the optical film is a polarizing plate, there will be strong shrinkage stress in high temperature environment, so compared with the general optical film, the adhesive layer requires higher durability. Recently, the durability required for the adhesive layer is very severe due to the increasing demand for improving the durability of the above-mentioned image display device.

Therefore, an object of the present invention is to provide an adhesive composition capable of forming an adhesive layer exhibiting excellent durability even under such severe durability conditions, an adhesive layer containing the adhesive composition, an adhesive layer containing the adhesive The optical film and the optical laminate of the adhesive layer.

Another object of the present invention is to provide a (meth)acrylic resin for an adhesive composition that can form an adhesive layer that exhibits excellent durability even under the severe durability conditions described above.

The inventors of the present invention have diligently examined to solve the above-mentioned problems, and have completed the present invention.

That is, the present invention includes those described below.

[1] An adhesive composition comprising a (meth)acrylic resin (A), a crosslinking agent (B) and a silane compound (C), wherein the (meth)acrylic resin (A) is derived from In the structural unit derived from (meth)acrylate (a1) containing acetoacetyl group and the structural unit derived from (meth)acrylate (a2) containing hydroxyl group, the mass ratio of the above structural units (a2) /(a1) is 0.5 to 5.

[2] The adhesive composition according to [1], wherein the weight average molecular weight of the (meth)acrylic resin (A) is 1 million or more in terms of polystyrene.

[3] The adhesive composition according to [1] or [2], wherein the (meth)acrylic resin (A) further contains an acrylic acid derived from a homopolymer whose glass transition temperature is less than 0°C. The structural unit of the ester (a3) and the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more.

[4] The adhesive composition according to any one of [1] to [3], wherein the constituent unit derived from an alkyl acrylate (a3) whose glass transition temperature is less than 0°C in a homopolymer and The mass ratio (a3)/(a4) of the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more is 0.1-4.

[5] The adhesive composition according to any one of [1] to [4], wherein (meth) The ratio of the structural unit derived from the carboxyl group-containing (meth)acrylate contained in acrylic resin (A) is 1.0 mass parts or less.

[6] The adhesive composition according to any one of [1] to [5], wherein the (meth)acrylic resin (A) further contains a (meth)acrylamide-based monomer the constituent unit.

[7] The adhesive composition according to any one of [1] to [6], wherein the crosslinking agent (B) is an isocyanate compound.

[8] The adhesive composition according to any one of [1] to [7], wherein the ratio of the crosslinking agent (B) to 100 parts by mass of the (meth)acrylic resin (A) is 0.01 to 10 parts by mass.

(式中，B表示碳數3至20之烷二基或碳數3至20之二價脂環式烴基，構成前述烷二基及前述脂環式烴基之-CH₂-可經取代為-O-或-CO-，R¹表示碳數1至5之烷基，R²、R³、R⁴、R⁵及R⁶分別獨立表示碳數1至5之烷基或碳數1至5之烷氧基)。 [9] The adhesive composition according to any one of [1] to [8], wherein the silane compound (C) is a silane compound represented by the following formula (c1);

(In the formula, B represents an alkanediyl group with 3 to 20 carbons or a divalent alicyclic hydrocarbon group with 3 to 20 carbons, and the -CH ₂ - constituting the alkanediyl group and the alicyclic hydrocarbon group can be substituted with - O- or -CO-, R ¹ represents an alkyl group with 1 to 5 carbons, R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently represent an alkyl group with 1 to 5 carbons or an alkyl group with 1 to 5 carbons alkoxyl).

[10] The adhesive composition according to any one of [1] to [9], wherein the ratio of the silane compound (C) to 100 parts by mass of the (meth)acrylic resin (A) is 0.01 to 10 parts by mass.

[11] The adhesive composition according to any one of [1] to [10], which substantially does not contain a photopolymerization initiator or its decomposition product.

[12] The adhesive composition according to any one of [1] to [11], which further contains an ionic compound (D).

[13] The adhesive composition according to [12], wherein the ratio of the ionic compound (D) is 0.01 to 10 parts by mass based on 100 parts by mass of the (meth)acrylic resin (A).

[14] The adhesive composition as described in [12] or [13], wherein the anion constituting the ionic compound (D) is composed of bis(trifluoromethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, bis(fluorosulfonyl) At least one selected from the group consisting of acyl)imide anion and tetrakis(pentafluorophenyl)borate anion.

[15] An adhesive layer comprising the adhesive composition described in any one of [1] to [14].

[16] The adhesive layer according to [15], wherein the adhesive layer has a gelation rate of 70 to 90%.

[17] An optical film with an adhesive layer, comprising an optical film and an adhesive layer on at least one surface of the optical film, the adhesive layer being the adhesive layer described in [15] or [16].

[18] An optical laminate comprising the optical film with an adhesive layer described in [17], and a base material laminated on the adhesive layer side of the optical film with an adhesive layer.

[19] A (meth)acrylic resin (A) for an adhesive composition comprising a structural unit derived from (meth)acrylate (a1) containing an acetoacetyl group, and a structural unit derived from The structural unit of (meth)acrylate (a2) of hydroxyl group has a mass ratio (a2)/(a1) of 0.5 to 5 and a weight average molecular weight of 1 million or more in terms of polystyrene.

[20] The (meth)acrylic resin (A) for an adhesive composition as described in [19], wherein the (meth)acrylic resin (A) further includes a glass transition temperature derived from a homopolymer The structural unit of the alkyl acrylate (a3) which is less than 0 degreeC, and the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more.

[21] The (meth)acrylic resin (A) for an adhesive composition according to [19] or [20], wherein the homopolymer is derived from an alkyl acrylate whose glass transition temperature is less than 0°C The mass ratio (a3)/(a4) of the structural unit of (a3) to the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more is 0.1-4.

[22] The (meth)acrylic resin (A) for an adhesive composition as described in any one of [19] to [21], wherein the (meth)acrylic resin (A) is composed of The ratio of the structural unit derived from the carboxyl group-containing (meth)acrylate contained in (meth)acrylic-type resin (A) is 1.0 mass parts or less with respect to 100 mass parts of all structural units.

[23] The (meth)acrylic resin (A) for an adhesive composition as described in any one of [19] to [22], wherein the (meth)acrylic resin (A) further contains It is a constituent unit of (meth)acrylamide monomer.

According to the adhesive composition of the present invention, an adhesive layer having excellent durability even under severe durability conditions, an optical film with the adhesive layer, and an optical laminate can be formed. Furthermore, according to the adhesive composition containing the (meth)acrylic resin for adhesive compositions of this invention, the adhesive layer which has excellent durability even under severe durability conditions can be formed.

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

2‧‧‧Polarizer

3‧‧‧1st resin film

4‧‧‧Second resin film

5, 6, 7, 8, 9‧‧‧optical laminate

10‧‧‧optical film

10a, 10b‧‧‧polarizer

20‧‧‧adhesive layer

30‧‧‧Metal layer

40‧‧‧substrate

50‧‧‧resin layer

The schematic cross-sectional view in Fig. 1 shows an example of an optical film with an adhesive layer of the present invention.

The schematic cross-sectional view in Fig. 2 shows an example of the layer configuration of a polarizing plate.

The schematic cross-sectional view in Fig. 3 shows another example of the layer configuration of the polarizing plate.

Fig. 4 is a schematic cross-sectional view showing an example of the optical laminate of the present invention.

Fig. 5 is a schematic cross-sectional view showing another example of the optical laminate of the present invention.

Fig. 6 is a schematic cross-sectional view showing another example of the optical laminate of the present invention.

Fig. 7 is a schematic cross-sectional view showing another example of the optical layered body of the present invention.

Fig. 8 is a schematic cross-sectional view showing another example of the optical layered body of the present invention.

[1] Adhesive composition

The adhesive composition of the present invention contains (meth)acrylic resin (A), crosslinking agent (B) and silane compound (C).

[1-1] (Meth)acrylic resin (A)

The (meth)acrylic resin (A) preferably contains 50 mass % of structural units derived from (meth)acrylic monomers relative to 100 mass % of all structural units constituting the (meth)acrylic resin (A) % or more of polymers or copolymers, the above-mentioned constituent units derived from (meth)acrylic monomers are more preferably 70% by mass or more, and more preferably 90% by mass or more, and include The structural unit of the (meth)acrylate (a1) with an acyl group and the structural unit derived from the (meth)acrylate (a2) containing a hydroxyl group, the mass ratio (a2)/(a1) of the aforementioned structural units is 0.5 to 5. In the adhesive composition of the present invention, the (meth)acrylic resin (A) contains the constituent units (a1) and (a2) in a specific mass ratio, so that it can form an adhesive having excellent durability even in a high-temperature environment. Adhesive layer.

Also, in this specification, "(meth)acrylic acid" means "acrylic acid" or "methacrylic acid", and similarly, "(meth)acrylate" or "(meth)acryl" means "Acrylic" or "methacrylate", "acryl" or "methacryl". In addition, in this specification, durability means, for example, the property of suppressing floating and peeling at the interface between the adhesive layer and the optical member adjacent thereto under high-temperature environment, high-temperature and high-humidity environment, repeated high-temperature and low-temperature environment, etc. (also known as anti-peeling property) and can suppress the undesirable characteristics such as foaming of the adhesive layer (also known as anti-foaming property). In addition, in this specification, the anti-agglomeration failure property means the characteristic which can suppress the aggregation failure (or cracking) of an adhesive layer.

The (meth)acrylate (a1) containing an acetoacetyl group may contain a substituent other than an acetoacetyl group, and a cyano group etc. are mentioned as a substituent. Specific examples of (meth)acrylates (a1) containing acetoacetyl group include: for example, acetylacetyloxyalkyl (meth)acrylate, such as acetylacetyloxyethyl (meth)acrylate Ester, acetylacetyloxypropyl (meth)acrylate, acetylacetyloxybutyl (meth)acrylate, etc. (meth)acrylacetyloxy C _2-10 alkyl esters; with substitution (Meth)acrylic esters containing acetyl acetyl groups, such as 2-cyanoacetyl oxyethyl (meth) acrylate, etc. (meth) cyano acetyl acetyl oxy C _{2 -10} alkyl esters etc. From the viewpoint of the durability of the adhesive layer and the ease of acquisition, among these, acetylacetyloxyethyl (meth)acrylate and acetylacetyloxypropyl (meth)acrylate are preferred. esters, acetylacetyloxybutyl (meth)acrylate, especially among these, 2-acetylacetyloxyethyl (meth)acrylate is more preferred. These acetoacetyl group-containing (meth)acrylates (a1) can be used alone or in combination of two or more.

Specific examples of (meth)acrylate (a2) containing a hydroxyl group include: 1-hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 1-hydroxyl (meth)acrylate Butyl, 1-hydroxypentyl (meth)acrylate, 1-hydroxyheptyl (meth)acrylate, etc. 1-hydroxy C _1-8 alkyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate , 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, 2-hydroxyhexyl (meth)acrylate, etc. (meth)acrylic acid 2-Hydroxy C _2-9 alkyl ester; 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, 3-hydroxy(meth)acrylate 3-Hydroxy C _3-10 alkyl (meth)acrylate, 3-hydroxyheptyl (meth)acrylate, etc.; 4-hydroxybutyl (meth)acrylate, 4-hydroxypentyl (meth)acrylate 4-hydroxy C _4-11 alkyl (meth)acrylate such as ester, 4-hydroxyhexyl (meth)acrylate, 4-hydroxyheptyl (meth)acrylate, 4-hydroxyoctyl (meth)acrylate, etc.; 2-Chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, (methyl ) 5-hydroxypentyl acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, 5-hydroxyoctyl (meth)acrylate, 5-hydroxynonyl (meth)acrylate 5-Hydroxy C _5-12 alkyl (meth)acrylate; 6-Hydroxyhexyl (meth)acrylate, 6-Hydroxyheptyl (meth)acrylate, 6-Hydroxyoctyl (meth)acrylate, 6-Hydroxynonyl (meth)acrylate, 6-hydroxydecyl (meth)acrylate, etc. 6-hydroxy C _6-13 alkyl (meth)acrylate; 7-hydroxyheptyl (meth)acrylate, (meth)acrylate Base) 7-hydroxyoctyl acrylate, 7-hydroxynonyl (meth)acrylate, 7-hydroxydecyl (meth)acrylate, 7-hydroxyundecyl (meth)acrylate, etc. 7-(meth)acrylate Hydroxy C _7-14 alkyl ester; 8-hydroxyoctyl (meth)acrylate, 8-hydroxynonyl (meth)acrylate, 8-hydroxydecyl (meth)acrylate, 8-hydroxydecyl (meth)acrylate Monoester, 8-hydroxydodecyl (meth)acrylate, etc. 8-hydroxy C _8-15 alkyl (meth)acrylate; 9-hydroxynonyl (meth)acrylate, 9-hydroxydecyl (meth)acrylate Esters, 9-hydroxyundecyl (meth)acrylate, 9-hydroxydodecyl (meth)acrylate, 9-hydroxytridecyl (meth)acrylate, etc. 9-hydroxy C _9-16 (meth)acrylate Alkyl esters; 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl (meth)acrylate, 10-Hydroxytetradecyl (meth)acrylate and other 10-hydroxyl C _10-17 alkyl esters of (meth)acrylate; Base) 11-hydroxyundecyl acrylate, 11-hydroxydodecyl (meth)acrylate, 11-hydroxytridecyl (meth)acrylate, 11-hydroxytetradecyl (meth)acrylate, (meth) 11-hydroxypentadecyl acrylate and other 11-hydroxy C _11-18 alkyl (meth)acrylates; 12-hydroxydodecyl (meth)acrylate, 12-hydroxytridecyl (meth)acrylate, (meth)acrylate ) 12-hydroxy tetradecyl acrylate and other 12-hydroxy C _12-19 alkyl (meth)acrylate; 13-hydroxy pentadecyl (meth)acrylate, 13-hydroxy tetradecyl (meth)acrylate, (meth)acrylate Base) 13-hydroxypentadecyl acrylate, etc. (meth)acrylate 13-hydroxyl C _13-20 alkyl ester; (meth)acrylate 14-hydroxytetradecyl, (meth)acrylate 14-hydroxypentadecyl, etc. ( 14-hydroxyl C _14-21 alkyl methacrylate; 15-hydroxypentadecyl (meth)acrylate, 15-hydroxyheptadecanyl (meth)acrylate, etc. 15-hydroxyl C _15-22 (meth)acrylate Alkyl esters, etc.

Among them, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and (meth)acrylic acid are preferred from the viewpoint of durability of the adhesive layer and ease of acquisition. 2-Hydroxybutyl (meth)acrylate and other 2-hydroxy C _2-7 alkyl esters; 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-(meth)acrylate 3-Hydroxy C _3-8 alkyl (meth)acrylate; 4-hydroxybutyl (meth)acrylate, 4-hydroxypentyl (meth)acrylate, 4-hydroxyhexyl (meth)acrylate 4-Hydroxy C _4-9 alkyl (meth)acrylate; 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, 5-hydroxyoctyl (meth)acrylate, 5-hydroxynonyl (meth)acrylate, 5-hydroxy C _5-9 alkyl (meth)acrylate, etc., especially among these, (meth) 2-Hydroxyethyl acrylate. These hydroxyl group-containing (meth)acrylates (a2) can be used individually or in combination of 2 or more types.

The ratio of the structural unit derived from the (meth)acrylate (a1) containing acetoacetyl group is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of all the structural units constituting the (meth)acrylic resin , more preferably 0.1 to 5 parts by mass, and more preferably 0.5 to 3 parts by mass. Furthermore, the ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate (a2) is preferably 0.01 to 20 mass parts with respect to 100 mass parts of all structural units constituting the (meth)acrylic resin, and more preferably It is preferably 1 to 10 parts by mass, more preferably 1.5 to 5 parts by mass. If the ratio of these structural units is the said range, the durability of an adhesive layer can be improved further.

Mass ratio (a2)/( a1) is 0.5 to 5, preferably 0.7 to 4.5, more preferably 1 to 4, still more preferably 1.2 to 3.7, particularly preferably 1.5 to 3.5. When these mass ratios are in the said range, the durability of an adhesive layer can be improved further.

The (meth)acrylic resin (A) may further contain a structural unit derived from an alkyl acrylate (a3) whose glass transition temperature of the homopolymer is less than 0° C., and a homopolymer whose glass transition temperature is A constituent unit of alkyl acrylate (a4) at 0°C or higher.

Alkyl acrylates (a3) whose glass transition temperature (Tg) of the homopolymer is less than 0°C include, for example, ethyl acrylate, n-propyl acrylate and isopropyl acrylate, n-butyl acrylate and isobutyl acrylate, acrylic acid n-pentyl acrylate, n-hexyl acrylate and isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate and isooctyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate and isononyl acrylate, n-decyl acrylate and Straight-chain or branched-chain alkyl acrylates such as isodecyl acrylate and n-dodecyl acrylate with an alkyl group having about 2 to 12 carbon atoms. The alkyl acrylate (a3) may be an alkyl acrylate (cycloalkyl acrylate) having an alicyclic structure, and preferably has a carbon number of 2 to The alkyl acrylate of 10 is more preferably an alkyl acrylate having a carbon number of 3 to 8, more preferably an alkyl acrylate having a carbon number of 4 to 6, and particularly preferably n-butyl acrylate. Use of n-butyl acrylate improves followability and is advantageous, for example, in anti-peeling properties. These alkyl acrylates (a3) can be used individually or in combination of 2 or more types.

Examples of alkyl acrylates (a4) having a homopolymer Tg of 0°C or higher include methyl acrylate, cycloalkyl acrylate (such as cyclohexyl acrylate, isobornyl acrylate, etc.), stearyl acrylate, Tributyl ester and the like are particularly preferred and methyl acrylate is preferred. If methyl acrylate is used, the strength of the adhesive layer at high temperature durability can be improved, for example, the resistance to coagulation damage can be improved. These alkyl acrylates (a4) can be used individually or in combination of 2 or more types. Moreover, the homopolymer Tg of alkyl acrylate can refer to the literature value, such as POLYMER HANDBOOK (Wiley-Interscience), for example.

From the viewpoint of the durability and reworkability of the adhesive layer, the structural unit (a3 ) and (a4), the total ratio may be, for example, 40 parts by mass or more. The lower limit of the total ratio of the aforementioned constituent units (a3) and (a4) is preferably 50 parts by mass, more preferably 60 parts by mass, still more preferably 70 parts by mass, particularly preferably 75 parts by mass. Furthermore, the upper limit of the total ratio of the aforementioned constituent units (a3) and (a4) is preferably 98 parts by mass, more preferably 95 parts by mass, and still more preferably 90 parts by mass. The total ratio of the constituent units (a3) and (a4) can be any combination of the lower limit and the upper limit, for example, it can be 50 to 98 parts by mass, preferably 70 to 95 parts by mass, more preferably 75 to 95 parts by mass share.

When the homopolymer Tg of the alkyl acrylate (a3) is less than 0°C and the homopolymer Tg of the alkyl acrylate (a4) is 0°C or higher, both anti-agglomeration damage and followability (peeling resistance) can be achieved. , can improve the durability against the dimensional change of the optical film (such as polarizing plate).

The mass ratio of the constituent unit derived from the alkyl acrylate (a3) whose glass transition temperature of the homopolymer is less than 0°C to the constituent unit derived from the alkyl acrylate (a4) whose glass transition temperature is 0°C or higher (a3 )/(a4), preferably from 0.1 to 4, more preferably from 0.15 to 3.5, and more preferably from 0.2 to 2.5. If these mass ratios are in the said range, the durability of an adhesive layer can be improved further. The higher the ratio of the structural unit derived from the alkyl acrylate (a3) whose glass transition temperature is less than 0°C, the better the followability, and it is derived from the composition of the alkyl acrylate (a4) whose glass transition temperature is 0°C or higher The larger the ratio of the unit, the higher the anti-agglutination destructiveness. Furthermore, if the alkyl acrylate (a4) whose glass transition temperature of the homopolymer is 0° C. or higher is contained in a larger ratio than the alkyl acrylate (a3) whose glass transition temperature of the homopolymer is less than 0° C., it can be further improved. Durability, exhibits excellent durability even under more severe durability conditions.

The (meth)acrylic resin (A) may further contain a structural unit derived from a substituent-containing alkyl acrylate.

Alkyl acrylates containing substituents include, for example, alkyl acrylates in which substituents have been introduced into the alkyl groups in the aforementioned alkyl acrylates (a3) and (a4) (in other words, hydrogen atoms of the alkyl groups are replaced by substituents). The substituent may be, for example, aryl (eg, phenyl, etc.), aryloxy (eg, phenoxy, etc.), alkoxy (eg, methoxy, ethoxy, etc.) and the like. Alkyl acrylates containing substituents, for example: aryl alkyl acrylate (such as benzyl acrylate, phenethyl acrylate, etc.), alkoxyalkyl acrylate (such as 2-methoxyethyl acrylate, ethyl acrylate, etc.) oxymethyl ester, etc.), aryloxyalkyl acrylate (such as phenoxyethyl acrylate, etc.), aryloxypolyalkylene glycol monoacrylate, polyalkylene glycol monoacrylate, etc. Aryloxypolyalkylene glycol monoacrylate and the alkylene group of polyalkylene glycol monoacrylate, such as methylene, ethylidene, propylidene and other _C1-6 alkylene groups, are preferably alkylene groups. The repeating unit of the oxyalkylene group can be appropriately selected such as an ethyl group. The repeating unit of the alkylene group can be, for example, 1 to 7, preferably 1 to 5, especially 1 or 2. These alkyl acrylates can be used alone or in combination of two or more. By including alkyl acrylate containing aromatic rings such as aryl group and aryloxy group, the whitening of the polarizing plate during the durability test can be improved. Also, antistatic properties can be improved by containing alkyl acrylates containing ether structures such as alkoxy groups or polyalkylene glycol structures. From the viewpoint of the balance of whiteness, antistatic properties, and durability, it is preferable to include aryloxyalkyl acrylate and aryloxypolyalkylene glycol acrylate. Specifically, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, etc. are mentioned. In particular, it is preferable to use phenoxyethyl acrylate and phenoxydiethylene glycol acrylate.

With respect to 100 parts by mass of all the structural units constituting the (meth)acrylic resin (A), the ratio of the structural unit derived from the alkyl acrylate containing a substituent may be, for example, 0 to 40 parts by mass, preferably 3 to 40 parts by mass. 30 parts by mass, more preferably 5 to 25 parts by mass, especially 7 to 21 parts by mass. If this ratio is in the said range, the characteristics, such as the said whiteness, antistatic property, and durability, can be further improved.

(Meth)acrylic resin (A) may contain the structural unit derived from the other monomer other than the said structural unit. Other monomers can be used alone or in combination of two or more. Other monomers include: monomers with polar functional groups other than hydroxyl groups, (meth)acrylamide monomers, styrene monomers, vinyl monomers, and multiple (methyl) monomers in the molecule. Acryl monomer, etc.

Examples of monomers having polar functional groups other than hydroxyl groups include (meth)acrylates having substituents such as heterocyclic groups such as epoxy groups, substituted or unsubstituted amino groups, and carboxyl groups. Specifically, acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth)acrylate, caprolactone modified Tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran and other monomers with heterocyclic groups; ( Aminoethyl methacrylate, N,N-dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate and other monomers with substituted or unsubstituted amino groups; (Meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, carboxyalkyl (meth)acrylate (such as carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate) etc. have a carboxyl group of monomer. These monomers may be used alone or in combination of two or more. Moreover, from a viewpoint of preventing the fall of the peelability of the separation film which can be laminated|stacked on an adhesive layer, it is preferable not to contain substantially the structural unit derived from the monomer which has an amine group. Moreover, what does not contain substantially means that it is less than 1.0 mass parts with respect to 100 mass parts of all structural units which comprise a (meth)acrylic-type resin (A).

In the present invention, high durability is exhibited even without containing a structural unit derived from a monomer having a carboxyl group (also called a structural unit derived from a (meth)acrylate ester containing a carboxyl group) which is thought to increase the corrosivity of ITO Therefore, it can take into account durability and ITO corrosion resistance.

On the other hand, durability can be further improved when the structural unit derived from the monomer which has a carboxyl group [the structural unit derived from the carboxyl group-containing (meth)acrylate] is contained. In the present invention, durability can be effectively improved even if the proportion of constituent units derived from carboxyl group-containing (meth)acrylate is small. The constituent unit can suppress the corrosion of ITO and further improve the durability.

The ratio of the structural unit derived from the carboxyl group-containing (meth)acrylate is 1.0 mass parts or less with respect to 100 mass parts of all structural units which comprise a (meth)acrylic-type resin. The upper limit of the ratio of the structural unit derived from a carboxyl group-containing (meth)acrylate is preferably 0.8 parts by mass, more preferably 0.5 parts by mass, still more preferably 0.3 parts by mass, particularly preferably 0.2 parts by mass, Most preferably, it is 0.15 parts by mass. The lower limit of the ratio of constituent units derived from carboxyl group-containing (meth)acrylate is preferably 0 parts by mass, more preferably 0.001 parts by mass, still more preferably 0.005 parts by mass, particularly preferably 0.01 parts by mass, Most preferably, it is 0.05 parts by mass. The proportion of constituent units derived from carboxyl-containing (meth)acrylates can be any combination of the upper limit and lower limit, for example, it can be 0 to 1 part by mass, preferably 0 to 0.8 part by mass, More preferably, it is 0.001 to 0.5 parts by mass, more preferably 0.005 to 0.3 parts by mass, particularly preferably 0.01 to 0.2 parts by mass, especially preferably 0.05 to 0.15 parts by mass. When the ratio of the structural unit derived from the carboxyl group-containing (meth)acrylate is below the upper limit, ITO corrosion can be suppressed, and when it is more than the lower limit, durability can be improved.

(Meth)acrylamide-based monomers can be, for example, N-methylolacrylamide, 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-oxo Butyl)acrylamide, N-[2-(2-oxo-1-imidazolidinyl)ethyl]acrylamide, 2-acrylamino-2-methyl-1-propanesulfonic acid , N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(1-methylethoxy Meth)acrylamide, N-(1-methylpropoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide [alias: N-(isobutoxy Meth)acrylamide], N-(butoxymethyl)acrylamide, N-(1,1-dimethylethoxymethyl)acrylamide, N-(2-methoxyethyl) base) 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. By containing the structural unit derived from the (meth)acrylamide-based monomer, the durability of the adhesive layer can be further improved. In particular, among these, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N- (butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, and the like.

The ratio of the structural unit derived from a (meth)acrylamide-type monomer is 5 mass parts or less with respect to 100 mass parts of all structural units which comprise a (meth)acryl-type resin. The upper limit of the ratio of the constituent 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 of the proportion of constituent units derived from (meth)acrylamide-based monomers is preferably 0 parts by mass, more preferably 0.001 parts by mass, still more preferably 0.01 parts by mass, particularly preferably 0.1 parts by mass . The proportion of constituent units derived from (meth)acrylamide-based monomers can be any combination of the upper limit and lower limit, for example, it can be 0 to 5 parts by mass, preferably 0.001 to 3 parts by mass , more preferably 0.01 to 2 parts by mass, and more preferably 0.1 to 1 part by mass. When the ratio of the structural unit derived from a (meth)acrylamide-type monomer is the said range, the durability of an adhesive layer can be improved further.

Examples of styrene-based monomers include: styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene , butylstyrene, hexylstyrene, heptylstyrene, octylstyrene and other alkylstyrenes; fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene and other halogenated styrenes; Nitrostyrene; Acetylstyrene; Methoxystyrene; Divinylbenzene, etc.

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

Examples of monomers with multiple (meth)acryl groups in the molecule are: 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1 , 9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, three Propylene glycol di(meth)acrylate and other monomers with 2 (meth)acryl groups in the molecule; trimethylolpropane tri(meth)acrylate and other monomers with 3 (meth)acryl groups in the molecule Monomer etc.

In order to further improve the durability of the adhesive layer, the (meth)acrylic resin (A) preferably has a standard polystyrene-equivalent weight average molecular weight (Mw) of 1,000,000 or more by gel permeation chromatography (GPC). The lower limit of Mw is more preferably 1.1 million, more preferably 1.2 million, and particularly preferably 1.3 million. In addition, the upper limit of Mw is not particularly limited, but from the viewpoint of coatability when the adhesive composition is processed into, for example, a sheet (coated on a substrate), it is preferably 2.5 million, more preferably 2.2 million, and more preferably 2 million. Mw can be any combination of these upper and lower limits, for example, it can be 1 million to 2.5 million, more preferably 1.1 million to 2.2 million, and still more preferably 1.2 million to 2 million. Also, the molecular weight distribution represented by the ratio (Mw/Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is usually 1 to 10, preferably 2 to 8, and more preferably 3 to 6.

Furthermore, the (meth)acrylic resin (A) preferably has a single peak in the range of 10 million to 2.5 million Mw on the GPC elution curve. The use of the (meth)acrylic resin (A) with a peak number of 1 is advantageous in improving the durability of the adhesive layer, the optical film with the adhesive layer, and the optical laminate containing the same.

The obtained elution curve "has a single peak" in the above range means that Mw has only one maximum value in the range of 10 million to 2.5 million. In this specification, in the GPC elution curve, those whose S/N ratio is 30 or more are defined as peaks. In addition, the number of peaks in the GPC elution curve and the Mw and Mn of the (meth)acrylic resin (A) can be obtained according to the GPC measurement conditions described in the examples.

When the (meth)acrylic resin (A) is dissolved in ethyl acetate and becomes a solution with a concentration of 20% by mass, the viscosity at 25°C is preferably 30,000 mPa‧s or less, more preferably 100 to 20,000 mPa‧ s. When the viscosity is within the above range, it is advantageous from the viewpoint of applicability when the adhesive composition is applied to a base material. Also, the viscosity can be measured with a Brookfield viscometer.

The glass transition temperature (Tg) of the (meth)acrylic resin (A) may be, for example, -60 to 20°C, preferably -50 to 10°C, and more preferably -40 to 0°C. When the glass transition temperature is in the above-mentioned range, it is advantageous to improve the durability of the adhesive layer. Moreover, glass transition temperature can be measured with a differential scanning calorimeter (DSC).

(Meth)acrylic resin (A) can be manufactured by well-known methods, such as a solution polymerization method, block polymerization method, suspension polymerization method, emulsion polymerization method, etc., Especially preferably, it is a solution polymerization method. The solution polymerization method can be, for example, the following method: mix the monomer and the organic solvent, add a thermal polymerization initiator under a nitrogen environment, and stir at a temperature of 40 to 90°C, preferably 50 to 80°C, for 3 to 15 minutes. hours or so. In order to control the reaction, monomers and thermal polymerization initiators can be added continuously or intermittently during polymerization. The monomer and thermal polymerization initiator may be added to an organic solvent.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, and the like are used. As a photopolymerization initiator, 4-(2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone etc. are mentioned, for example. Examples of thermal polymerization initiators are: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane -1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxypentane Nitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-hydroxymethylpropionitrile) and other azo compounds; lauryl Peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate , tertiary butyl neodecanoate peroxide, tertiary butyl peroxypivalate, (3,5,5-trimethylhexyl) peroxide and other organic peroxides; potassium persulfate, Inorganic peroxides such as ammonium persulfate and hydrogen peroxide, etc. In addition, a redox system 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 monomers constituting the (meth)acrylic resin (A). The polymerization of (meth)acrylic resin (A) can use the polymerization method by active energy rays, for example, the polymerization method by ultraviolet rays etc. can be used.

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

[1-2] Crosslinking agent (B)

The adhesive composition of the present invention contains a crosslinking agent (B). This crosslinking agent (B) should just be what can react with the polar functional group containing a hydroxyl group or an acetoacetyl group in a (meth)acrylic-type resin (A). In the present invention, the hydroxyl group or acetylacetyl group introduced into the side chain of the (meth)acrylic resin (A) reacts with the crosslinking agent (B) to form Foaming, anti-peeling and anti-agglutination damage, etc.) cross-linked structure.

The cross-linking agent (B) can include conventional cross-linking agents, such as isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc., especially from the adhesive composition Isocyanate-based compounds are preferred from the viewpoints of pot life and crosslinking speed, and durability of the optical film with the adhesive layer and the optical laminate.

The isocyanate-based compound is preferably a compound having at least 2 isocyanate groups (-NCO) in the molecule, for example: aliphatic isocyanate-based compounds (such as hexamethylene diisocyanate, etc.), alicyclic isocyanate-based compounds ( Such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc.), aromatic isocyanate compounds (such as toluene diisocyanate, xylylene diisocyanate, diphenyl methyl methane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.) and the like. Furthermore, the crosslinking agent (B) may be an adduct (adduct) of the polyol compound of the aforementioned isocyanate-based compound [for example, adducts of glycerin, trimethylolpropane, etc.], isocyanate trimeric compound, biscondensate, etc. Urea-type compounds, polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc., and isocyanate compounds of urethane prepolymer type after addition reaction etc. derivatives. A crosslinking agent (B) can be used individually or in combination of 2 or more types. Among them, representative aromatic isocyanate-based compounds (such as toluene diisocyanate, xylylene diisocyanate, etc.), aliphatic isocyanate-based compounds (such as hexamethylene diisocyanate, etc.) or These adducts of polyol compounds (such as glycerol, trimethylolpropane, etc.). If the crosslinking agent (B) is an aromatic isocyanate compound and/or the polyol compound adduct thereof, the durability of the optical film with the adhesive layer can be improved. In particular, if it is an adduct of a cresyl diisocyanate type compound and/or these polyol compounds, durability can be further improved.

Relative to 100 parts by mass of (meth)acrylic resin (A), the ratio of crosslinking agent (B) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and more preferably 0.15 to 1 part by mass Parts, preferably 0.2 to 0.5 parts by mass. When the ratio of the crosslinking agent (B) is below the above-mentioned upper limit, it is beneficial to improve peeling resistance, and if it is above the above-mentioned lower limit, it is beneficial to improve foaming resistance and reworkability.

[1-3] Silane compound (C)

The adhesive composition contains a silane compound (C). By containing this silane compound (C), the adhesiveness (or adhesiveness) of an adhesive layer and a base material (for example, a metal layer, a transparent electrode, a glass substrate, etc.) etc. can be improved. The silane compound (C) can be any silane compound as long as it can be bonded to the reactive group (such as hydroxyl group, acetylacetyl group) of the (meth)acrylic resin (A), for example: vinyltrimethoxy Silane, Vinyltriethoxysilane, Vinylginseng(2-Methoxyethoxy)silane, 3-Glycidoxypropyltrimethoxysilane, 3-Glycidoxypropyltriethylsilane Oxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl ) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyl Trimethoxysilane, 1,3-bis(3'-trimethoxypropyl)urea, etc.

Moreover, the silane compound (C) may be a polysiloxane oligomer type compound, and if the polysiloxane oligomer is expressed as a combination of monomers, for example: 3-mercaptopropyldimethoxysilane or 3-mercaptopropyltrimethoxysilane/tetramethoxysilane oligomer, 3-mercaptomethyldimethoxysilane or 3-mercaptomethyltrimethoxysilane/tetraethoxysilane oligomer, 3-Mercaptopropyldiethoxysilane or 3-Mercaptopropyltriethoxysilane/Tetramethoxysilane Oligomer, 3-Mercaptomethyldiethoxysilane or 3-Mercaptomethyltriethoxy mercaptoalkyl silane/tetraethoxysilane oligomer and other mercaptoalkyl-containing oligomers; the mercaptoalkyl group of the mercaptoalkyl-containing oligomer is replaced by other substituents [such as 3-glycidoxypropyl group, (meth)acryloxypropyl group, vinyl group, amino group, etc.] oligomers, etc.

The silane compound (C) is preferably a silane compound represented by the following formula (c1). If the adhesive composition contains a silane compound represented by the following formula (c1), the adhesiveness (or adhesiveness) can be further improved, so an adhesive layer excellent in peel resistance can be formed. Moreover, this adhesive layer is also excellent in reworkability. Especially when the adhesive layer is applied (or laminated) to a transparent electrode (such as an ITO substrate, etc.) under a high-temperature environment, it can also maintain adhesion (or adhesiveness) and exhibit high durability.

(式中，B表示碳數1至20之烷二基或碳數3至20之二價脂環式烴基，構成前述烷二基及前述脂環式烴基之-CH₂-可經取代為-O-或-CO-，R¹表示碳數1至5之烷基，R²、R³、R⁴、R⁵及R⁶分別獨立表示碳數1至5之烷基或碳數1至5之烷氧基)

(In the formula, B represents an alkanediyl group with 1 to 20 carbons or a divalent alicyclic hydrocarbon group with 3 to 20 carbons, and the -CH ₂ - constituting the alkanediyl group and the alicyclic hydrocarbon group can be substituted with - O- or -CO-, R ¹ represents an alkyl group with 1 to 5 carbons, R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently represent an alkyl group with 1 to 5 carbons or an alkyl group with 1 to 5 carbons alkoxy)

In formula (c1), B represents, for example: methylene, ethylene, trimethylene, tetramethylene, hexamethylene, heptamethylene, octamethylene, etc. Base; cyclobutylene (such as 1,2-cyclobutylene), cyclopentyl (such as 1,2-cyclopentyl), cyclohexylene (such as 1,2-cyclohexyl), cyclopentyl Divalent alicyclic hydrocarbon groups with ₃ to 20 carbons such as octyl (such as 1,2-cyclooctyl); or the base of -CO-. Desirable B is an alkanediyl group having 1 to 10 carbon atoms. R ¹ represents an alkyl group with 1 to 5 carbons such as methyl, ethyl, propyl, isopropyl, butyl, second butyl, third butyl, pentyl, etc., R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently represent, for example, an alkyl group with 1 to 5 carbon atoms as exemplified by the aforementioned R ¹ ; or, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, the second An alkoxy group having 1 to 5 carbon atoms such as butoxy and tert-butoxy. Preferred R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are alkoxy groups having 1 to 5 carbon atoms. These silane compounds (C) can be used individually or in combination of 2 or more types.

Specific silane compounds (c1) include, for example: (trimethoxysilyl)methane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane , 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(trimethoxy silyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,6-bis(tripropoxysilyl)hexane, 1,8-bis(trimethoxysilyl) ) octane, 1,8-bis(triethoxysilyl) octane, 1,8-bis(tripropoxysilyl) octane and other bis(tri-C _1-5 alkoxysilyl) C _1-10 alkanes; bis(dimethoxymethylsilyl)methane, 1,2-bis(dimethoxymethylsilyl)ethane, 1,2-bis(dimethoxyethylsilyl) ) ethane, 1,4-bis(dimethoxymethylsilyl)butane, 1,4-bis(dimethoxyethylsilyl)butane, 1,6-bis(dimethoxy Methylsilyl)hexane, 1,6-bis(dimethoxyethylsilyl)hexane, 1,8-bis(dimethoxymethylsilyl)octane, 1,8-bis( Bis(dimethoxyethylsilyl)octane and other bis(di-C _1-5 alkoxy C _1-5 alkylsilyl)C _1-10 alkanes; 1,6-bis(methoxydimethylsilyl base) hexane, 1,8-bis(methoxydimethylsilyl) octane and other bis(mono C _1-5 alkoxy-di C _1-5 alkyl silyl) C _1-10 alkanes . Among them, 1,2-bis(trimethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1, 4-bis(trimethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, 1,8-bis(trimethoxysilyl) Bis(tri-C _1-3 alkoxysilyl)C _1-10 alkanes such as oxysilyl)octane, especially 1,6-bis(trimethoxysilyl)hexane, 1,8-bis (Trimethoxysilyl) octane. These silane compounds (c1) can be used individually or in combination of 2 or more types.

Relative to 100 parts by mass of (meth)acrylic resin (A), the ratio of the silane compound (C) is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 3 parts by mass, and more preferably 0.1 to 1 part by mass , particularly preferably 0.2 to 0.5 parts by mass. If the ratio of the silane compound (C) is below the above-mentioned upper limit, it is beneficial to suppress the oozing of the silane compound (C) from the adhesive layer; Layers, glass substrates, etc.) adhesion (or adhesion), is also conducive to improving peeling resistance and so on.

[1-4] Antistatic agent

The adhesive composition of the present invention may further contain an antistatic agent. By containing an antistatic agent, the antistatic property of the adhesive layer can be improved, for example, defects caused by static electricity generated when peeling off a release film, a protective film, etc. can be suppressed. As the antistatic agent, conventional ones are mentioned, and an ionic antistatic agent (ionic compound (D)) is preferable. Examples of the cation constituting the ionic antistatic agent (ionic compound (D)) include organic cations, inorganic cations, and the like. Examples of organic cations include pyridinium cations, imidazolium cations, ammonium cations, percite 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; alkaline earth metal cations such as magnesium cations and calcium cations; and the like. The anion constituting the ionic antistatic agent (ionic compound (D)) may be either an inorganic anion or an organic anion, but is preferably an anion containing a fluorine atom in terms of excellent antistatic performance. Anions containing fluorine atoms include, for example: hexafluorophosphate anion (PF ₆ ^- ), bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ^- ], bis(fluorosulfonyl) base) imide anion [(FSO ₂ ) ₂ N ^- ], tetrakis(pentafluorophenyl) borate anion [(C ₆ F ₅ ) ₄ B ^- ], etc. These antistatic agents can be used alone or in combination of two or more. Especially preferred are bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ^- ], bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N ^- ] and At least one selected from the group consisting of tetrakis(pentafluorophenyl) borate anion [(C ₆ F ₅ ) ₄ B ^- ]. The adhesive composition is preferably an ionic antistatic agent (ionic compound (D)) that is solid at room temperature because it is excellent in the temporal stability of the antistatic performance. Furthermore, the ionic compound (D) is preferably an ionic compound containing an anion containing a fluorine atom and an organic cation.

With respect to 100 parts by mass of the (meth)acrylic resin (A), the ratio of the ionic antistatic agent (ionic compound (D)) may be, for example, 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably Preferably it is 1 to 3 parts by mass.

[1-5] Other ingredients

The adhesive composition of the present invention may contain solvents, crosslinking catalysts, ultraviolet absorbers, weather-resistant stabilizers, tackifiers, plasticizers, softeners, dyes, pigments, inorganic fillers, light-scattering microparticles, etc. Single or two or more additives. Furthermore, an ultraviolet curable compound may be formulated in the adhesive composition, and after the adhesive layer is formed, it may be cured by irradiating ultraviolet light to form a harder adhesive layer. The cross-linking catalyst can be for example: hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, Amine-based compounds such as trimethylene diamine, polyamine-based resins, and melamine resins, etc.

From the viewpoint of improving the metal corrosion resistance of the adhesive layer, the optical film with the adhesive layer, and the optical laminate containing them, the adhesive composition of the present invention may contain a rust preventive agent. Antirust agents include, for example: triazole compounds such as benzotriazole compounds; thiazole compounds such as benzothiazole compounds; imidazole compounds such as benzyl imidazole compounds; imidazoline compounds; quinoline compounds; Pyridine-based compounds; pyrimidine-based compounds; indole-based compounds; amine-based compounds; urea-based compounds; sodium benzoate; benzyl thiol-based compounds; di-second butyl sulfide;

In a preferable aspect, the adhesive composition of this invention does not contain a photoinitiator and its decomposition product substantially. The reason for this is that the photopolymerization initiator and its decomposition product in the adhesive composition may hinder the formation of an adhesive layer excellent in durability. Here, substantially not containing means 1.0 parts by mass or less, preferably 0.1 parts by mass or less, more preferably 0.01 parts by mass or less, and more preferably 0.001 parts by mass or less, with respect to 100 parts by mass of the adhesive composition. Most preferably, it is 0 parts by mass.

As mentioned above, the adhesive composition of the present invention contains a specific (meth)acrylic resin (A), a crosslinking agent (B) and a silane compound (C), so that the adhesive composition composed of the adhesive composition can be improved. The durability of the agent layer can effectively prevent peeling (or floating) and foaming at the interface even in high temperature environments. Moreover, even if a strong shrinkage stress occurs, the adhesive layer can effectively relieve the stress, so it can prevent whitening that occurs when the optical film (such as a polarizing plate) shrinks. It is speculated that the reason is as follows: the (meth)acrylic resin (A) contained in the adhesive composition of the present invention has two functional groups with different reactivity in the side chain, that is, has a hydroxyl group and an ethyl group in the side chain. acyl acetyl group, and contains constituent units having each functional group in a specific mass ratio, so the adhesive composition can form an adhesive layer having a cross-linked structure and cross-linked structure optimal for exhibiting excellent durability. joint density.

[2] Adhesive layer, optical film with adhesive layer, and methods for producing the same

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

Moreover, the present invention also includes an optical film with an adhesive layer, comprising an optical film and the aforementioned adhesive layer layered on at least one area of the optical film.

The adhesive layer and the optical film attached to the adhesive layer of the present invention are formed of the aforementioned adhesive composition, so they also have excellent durability under severe durability conditions (for example, durability conditions above 100°C).

The schematic sectional view of Fig. 1 shows 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 laminated with an optical film 10 and an adhesive layer 20 on one side of 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 20, or implement the above-mentioned surface activity. chemical treatment (such as plasma treatment, corona treatment, etc.), especially the implementation of corona treatment.

When the optical film 10 is a single-sided protective polarizer as shown in Figure 2, the adhesive layer 20 is usually on the polarizer surface, that is, the area layer on the opposite side of the first resin film 3 in the polarizer 2 (preferably for direct stacking). When the optical film 10 is a double-sided protective polarizing plate as shown in FIG. 3, the adhesive layer 20 can be laminated on the outer surface of any one of the first and second resin films 3 and 4, or can be laminated on the outer surface of both. .

An antistatic layer may be further provided between the optical film 10 and the adhesive layer 20 . The antistatic layer can be used: 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 adhesive layer-attached optical film 1 may include a separation film (peeling film) laminated on the outer surface of the adhesive layer 20 . This separation film is usually peeled off when using the adhesive layer 20 (for example, when it is laminated on a transparent electrode or a glass substrate). The separation membrane can be applied to the surface where the adhesive layer 20 is to be formed, for example, on a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate. Silicone treatment and other mold release treatment.

The adhesive layer 20 can be obtained by dissolving or dispersing the components constituting the above-mentioned adhesive composition in a solvent to prepare a solvent-containing adhesive composition, and then applying it on the surface of the optical film 10 and drying it to form the adhesive layer 20 . Optical film 1 of adhesive layer. Furthermore, by forming the adhesive layer 20 on the release-treated surface of the separation film in the same manner as above, and laminating (transferring) the adhesive layer 20 on the surface of the optical film 10, an optical film with an adhesive layer can also be obtained. Film 1.

The thickness of the adhesive layer is usually 2 to 40 μm, preferably 5 to 30 μm, more preferably 10 to 30 μm from the viewpoints of durability of the optical film with the adhesive layer and reworkability of the optical film with the adhesive layer. 25 μm. When the thickness of the adhesive layer is not more than the upper limit, the reworkability is good, and when it is more than the lower limit, the followability (or followability) of the adhesive layer to the dimensional change of the optical film is good.

The adhesive layer is preferably one that exhibits a storage elastic modulus of 0.1 to 5 MPa in a temperature range of 23 to 80°C. Thereby, the durability of the optical film with the adhesive layer can be improved more effectively. "Exhibiting a storage modulus of elasticity of 0.1 to 5 MPa in the temperature range of 23 to 80° C." means that the storage modulus of elasticity at any temperature in the range is a value within the above range. The storage modulus of elasticity usually decreases as the temperature rises, so if the storage modulus of elasticity at 23°C and 80°C is within the above range, it can be assumed that the temperature in this range shows a storage modulus of elasticity within the above range. The storage elastic modulus of the adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device "DYNAMIC ANALYZER RDA II" manufactured by REOMETRIC Corporation.

As one index of the crosslink density, the gel ratio can be used. The adhesive layer of the present invention has a predetermined cross-linking density, so it exhibits a predetermined gelation rate. That is, the gelation rate of the adhesive layer of the present invention may be, for example, 70 to 90% by mass, preferably 75 to 90% by mass, and more preferably 75 to 85% by mass. If the gelation rate is above the lower limit, it is beneficial to the foam resistance and reworkability of the adhesive layer, and if the gelation rate is below the upper limit, it is beneficial to the peeling resistance. In addition, the gelation rate can be measured by the method described in the examples.

The adhesive layer system of the present invention has a predetermined adhesive force. That is to say, when the above-mentioned adhesive layer is pasted on the glass substrate, under the conditions of a temperature of 23°C and a relative humidity of 50%, the adhesive force of the aforementioned adhesive layer after 24 hours is preferably 0.5 to 25N, more preferably 0.5 to 20N, more preferably 0.5 to 15N, particularly preferably 1 to 10N, especially preferably 1.5 to 10N. When the adhesive force is more than the lower limit, it is advantageous for reworkability. Moreover, adhesive force can be measured by the method described in the Example.

[2-1] Optical film

The optical film 10 constituting the optical film 1 with an adhesive layer can be various optical films (films having optical properties) that can be incorporated in image display devices such as liquid crystal display devices. The optical film 10 can be a single-layer structure (such as polarizers, retardation films, brightness enhancement films, anti-glare films, anti-reflection films, diffusion films, optical functional films such as light-concentrating films, etc.), and can also be a multi-layer structure ( Such as polarizers, retardation plates, etc.). The optical film 10 is preferably a polarizer, a polarizer, a retardation plate or a retardation film, especially preferably a polarizer or a polarizer. Moreover, in this specification, an optical film means the film which functions to display an image (display screen etc.) (for example, the film which functions to improve the visibility of an image). In addition, in this specification, a polarizer means a polarizer having a resin film or a resin layer layered on at least one surface thereof, and a retardation plate means a resin film or a resin layer layered on at least one surface of a retardation film.

[2-2] Polarizing plate

2 and 3 are schematic cross-sectional views showing examples of layer configurations of polarizing plates. The polarizing plate 10a shown in Figure 2 is a single-sided protective polarizing plate with a first resin film 3 layered (or laminated) on one surface of the polarizing plate 2, and the polarizing plate 10b shown in Figure 3 is on the polarizing plate 2 The other side is further laminated (or laminated) with the second resin film 4 on both sides to protect the polarizing plate. The first and second resin films 3 and 4 can be bonded to the polarizer 2 through an adhesive layer and an adhesive layer not shown in the figure. In addition, the polarizing plates 10a and 10b may include other films and layers other than the first and second resin films 3 and 4 .

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

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

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably more than 98 mol%. The polyvinyl alcohol resin can be modified, for example, it can be 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. Moreover, the average degree of polymerization of a polyvinyl-alcohol-type resin can be calculated|required based on JISK6726.

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

The polarizer 2 is, for example, subjected to a uniaxial stretching step on a raw film, a step of dyeing the film with a dichroic dye to adsorb the dichroic dye, a step of treating the film with an aqueous solution of boric acid, a step of washing the film, and finally drying the film. manufacture. The thickness of the polarizer 2 is usually 1 to 30 μm, preferably 20 μm or less, more preferably 15 μm or less, especially 10 μm or less from the viewpoint of thinning the optical film 1 with an adhesive layer.

The polarizer 2 formed by absorbing and aligning dichroic dyes on a polyvinyl alcohol-based resin film uses a single film of a polyvinyl alcohol-based resin film as a raw material film, except that the film is subjected to uniaxial stretching and dichroic dyes. In addition to the method of dyeing treatment (referred to as method (1)), it is also possible to obtain a layer having a polyvinyl alcohol-based resin by applying a coating liquid (aqueous solution, etc.) containing a polyvinyl alcohol-based resin to the base film and drying After the base film, each base film is uniaxially stretched, and the stretched polyvinyl alcohol-based resin layer is dyed with a dichroic dye, and then the method of peeling and removing the base film (referred to as the method ( 2)) get. The base film can be a film made of the same thermoplastic resin as the thermoplastic resin that can constitute the first and second resin films 3 and 4 described later, preferably polyester resin such as polyethylene terephthalate, Films made of polycarbonate-based resins, cellulose-based resins such as cellulose triacetate, cyclic polyolefin-based resins such as norbornene-based resins, polystyrene-based resins, and the like. If the above-mentioned method (2) is used, it is easy to manufacture a thin-film polarizer 2, and it is also easy to manufacture a polarizer 2 with a thickness of 7 μm or less.

The first and second resin films 3 and 4 are independently independent and have light transmittance. They are preferably films comprising optically transparent thermoplastic resins. For example, they can be made of chain polyolefin resins (such as polyethylene resins, Polypropylene-based resins, etc.), polyolefin-based resins such as cyclic polyolefin-based resins (such as norbornene-based resins, etc.); cellulose-based resins (such as cellulose ester-based resins, etc.); polyester-based resins (such as poly Ethylene phthalate, polyethylene naphthalate, polybutylene terephthalate, etc.); polycarbonate resins (such as 2,2-bis(4-hydroxyphenyl)propane and other bisphenols) Derived polycarbonate, etc.); (meth)acrylic resin; polystyrene resin; polyether ether ketone resin; Among them, the first and second resin films 3 and 4 are respectively made of cyclic polyolefin resin, polycarbonate resin, cellulose resin, polyester resin, and (meth)acrylic resin. The formed film is preferred, and a film formed of cellulose-based resin, cyclic polyolefin-based resin, or the like is more preferable.

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

Cyclic polyolefin-based resin is a general term for resins containing cyclic olefins as polymerized units represented by norcamphene, tetracyclododecene (alternative name: dimethyloctahydronaphthalene) or their derivatives. Cyclic polyolefin-based resins include ring-opening (co)polymers of cyclic olefins and their hydrogenated products, addition polymers of cyclic olefins, cyclic olefins and chain olefins such as ethylene and propylene, or olefins with vinyl groups. Copolymers of aromatic compounds and modified (co)polymers modified by unsaturated carboxylic acids or their derivatives. Among these, norbornene-based resins using norbornene-based monomers such as norbornene and polycyclic norbornene-based monomers as cyclic olefins are preferable.

The cellulose-based resin is preferably a cellulose ester-based resin, that is, a partial or complete esterification of cellulose, for example: acetate, propionate, butyrate, and mixed esters of cellulose Wait. Among these, cellulose triacetate, cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate, and the like are preferable.

Polyester-based resins are resins other than the above-mentioned cellulose ester-based resins having ester bonds, and are generally composed of polycondensates of polycarboxylic acids or their derivatives and polyhydric alcohols. Examples of polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polytrimethylene terephthalate. , Polytrimethylene naphthalate, polycyclohexanedimethylene terephthalate, polycyclohexanedimethylene naphthalate, etc.

Polycarbonate resin is a polyester formed from carbonic acid and glycol or bisphenol. Among them, aromatic polycarbonate having diphenylalkane in the molecular chain is preferable from the viewpoint of heat resistance, weather resistance and acid resistance. Examples of polycarbonate include: 2,2-bis(4-hydroxyphenyl)propane (alias bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4- Polycarbonate derived from bisphenol, such as hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane, 1,1-bis(4-hydroxyphenyl)ethane, etc.

The (meth)acrylic resin that can constitute the first and second resin films 3 and 4 can be a polymer mainly composed of structural units derived from methacrylate (for example, it contains 50% by mass or more), Copolymers copolymerized with other copolymerizable components are preferred. The (meth)acrylic resin may contain two or more structural units derived from methacrylate. Examples of the methacrylate include C ₁ to C ₄ alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

Acrylic ester is mentioned as a copolymerization component which can be copolymerized with methacrylate. The acrylate is preferably C ₁ to C ₈ alkyl esters 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; (methyl) Vinyl cyanide compounds such as acrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; - Compounds other than acrylates with carbon double bonds. 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.

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

The (meth)acrylic resin may contain acrylic rubber particles from the viewpoints of film-forming properties of a film, shock resistance of a film, and the like. The acrylic rubber particles refer to particles mainly composed of an elastic polymer mainly composed of acrylate, and examples include those having a single-layer structure consisting substantially only of an elastic polymer and those having a multi-layer structure comprising an elastic polymer as one layer. Examples of elastic polymers include: cross-linked elastic copolymers, which are mainly composed of alkyl acrylate 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 methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and other acrylic acid C ₁ to C ₈ alkyl esters. The carbon number of the alkyl group is preferably 4 or more.

Examples of other vinyl monomers that can be copolymerized with alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, more specifically, methyl methacrylate such as methyl Acrylates, aromatic vinyl compounds such as styrene, vinyl cyanide compounds such as (meth)acrylonitrile, etc. The cross-linking monomers include cross-linking compounds having at least two polymerizable carbon-carbon double bonds in the molecule, more specifically, ethylene glycol di(meth)acrylate, butanediol (meth)acrylates of polyhydric alcohols such as di(meth)acrylates, enyl (meth)acrylates such as allyl (meth)acrylates, divinylbenzene, and the like.

The content of the acrylic rubber particles is preferably at least 5 parts by mass, more preferably at least 10 parts by mass, based on 100 parts by mass of the (meth)acrylic resin. If the content of the acrylic rubber particles is too high, the surface hardness of the film will be lowered, and the solvent resistance to the organic solvent in the surface treatment agent will be lowered when the film is surface treated. Therefore, the content of the acrylic rubber particles is usually not more than 80 parts by mass, preferably not more than 60 parts by mass, based on 100 parts by mass of the (meth)acrylic resin.

化合物、(甲基)丙烯酸氰基酯化合物、鎳錯鹽等。 The first and second resin films 3 and 4 may contain common additives in the technical field of the present invention. Examples of additives include ultraviolet absorbers, infrared absorbers, organic dyes, pigments, inorganic pigments, antioxidants, antistatic agents, surfactants, lubricants, dispersants, heat stabilizers, and the like. Examples of ultraviolet absorbers include salicylate compounds, benzophenone compounds, benzotriazole compounds,

Compounds, (meth) cyanoacrylate compounds, nickel zirconium salts, etc.

Each of the first and second resin films 3 and 4 may be either an unstretched film or a uniaxially or biaxially stretched film. The first resin film 3 and/or the second resin film 4 may be a protective film that plays a role of protecting the polarizer 2, or may be a protective film that has an optical function as a retardation film described later. In addition, the first resin film 3 and the second resin film 4 may be the same or different films.

Moreover, the first resin film 3 and/or the second resin film 4 can be equipped with a hard coat layer, an anti-glare layer, an anti-reflection layer, a light diffusion layer, an antistatic layer, etc. on its outer surface (the surface opposite to the polarizer 2). layer, anti-fouling layer, conductive layer and other surface treatment layers (coating layer). The thicknesses of the first resin film 3 and the second resin film 4 are usually 1 to 150 μm, preferably 5 to 100 μm, more preferably 5 to 60 μm, and more preferably 50 μm or less (for example, 1 to 40 μm), especially 30 μm or less (for example, 5 to 25 μm).

Especially in small and medium-sized oriented polarizing plates such as smartphones and tablet terminals, it is required to be thinner, so thinner ones with a thickness of 30 μm or less are often used as the first resin film 3 and/or the second resin film 4, but In such a polarizing plate, the suppression force of the shrinkage force of the polarizing plate 2 is weak, and durability tends to be insufficient. Even when such a polarizing plate is used as the optical film 10, the adhesive layer-attached optical film 1 of the present invention has good durability.

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

Examples of water-based adhesives include commonly used water-based adhesives (for example, adhesives composed of polyvinyl alcohol-based resin aqueous solutions, water-based two-component urethane-based emulsion adhesives, aldehyde compounds, epoxy compounds, melamine, etc.) series compounds, methylol compounds, isocyanate compounds, amine compounds, polyvalent metal salts and other cross-linking agents, etc.). Among them, a water-based adhesive composed of a polyvinyl alcohol-based resin aqueous solution can be suitably used. Also, when using a water-based adhesive, after laminating the polarizer 2 and the first and second resin films 3 and 4, it is preferable to perform a drying step in order to remove water contained in the water-based adhesive. After the drying step, for example, an aging step 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 and electron rays, and examples thereof include curable compositions containing a polymerizable compound and a photopolymerization initiator, The curable composition of a reactive resin, the curable composition containing an adhesive resin and a photoreactive crosslinking agent, etc. are preferably ultraviolet curable adhesives.

When using an active energy ray-curable adhesive, after laminating the polarizer 2 and the first and second resin films 3 and 4, a drying step is performed if necessary, and then the active energy ray is cured by irradiating the active energy ray. Hardening step of adhesive hardening. The light source of active energy rays 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 a method of performing surface activation treatment such as saponification treatment, corona treatment, and plasma treatment on at least any one of the lamination surfaces. Wait. When bonding resin films to both sides of the polarizer 2, the adhesives used to bond the resin films may be the same type of adhesive or different types of adhesives.

The polarizing plates 10a and 10b may further contain other films or layers. Specific examples thereof include a brightness enhancement film, an antiglare film, an antireflection film, a diffusion film, a light concentrating film, an adhesive layer other than the adhesive layer 20, a coating layer, a protective film, etc. other than the retardation film described later. The protective film is a film used to protect the surface of the optical film 10 such as a polarizing plate from damage and dirt. Taking the optical film 1 with an adhesive layer as an example, a common example is to attach it to a metal layer, for example. , on the substrate and then removed by peeling off.

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

[2-3] Phase difference plate

As mentioned above, the retardation film contained in the retardation film is an optical film showing optical anisotropy, and may be the following stretched film: a stretched film obtained by stretching a resin film to about 1.01 to 6 times, and the resin film is In addition to the thermoplastic resins exemplified above as those that can be used in the first and second resin films 3 and 4, polyvinyl alcohol-based resins, polyarylate-based resins, polyimide-based resins, polyether resins, and polyvinyl alcohol-based resins are also included. Pine-based resins, polyvinylidene fluoride/polymethyl methacrylate-based resins, liquid crystal polyester-based resins, ethylene/vinyl acetate copolymer saponified products, polyvinyl chloride-based resins, etc. Among these, stretched films obtained by uniaxially stretching or biaxially stretching polycarbonate-based resin films, cyclic olefin-based resin films, (meth)acrylic-based resin films, or cellulose-based resin films are preferable. In addition, in this specification, the phase difference film also includes a zero retardation (Zero retardation) film. However, a zero-retardation film can also be used as a protective film. In addition, a film called a uniaxial retardation film, a wide viewing angle retardation film, a low photoelastic modulus retardation film, etc. can also be applied as the retardation film.

The zero-retardation film refers to a film whose in-plane retardation value _Re and thickness-direction retardation value _Rth are both -15 to 15 nm. This phase difference film is suitably used for the liquid crystal display device of IPS mode. Both the in-plane retardation value R _e and the thickness direction retardation value R _th are preferably -10 to 10 nm, more preferably both are -5 to 5 nm. The in-plane retardation value _Re and the thickness direction retardation value R _th described here are values at a wavelength of 590 nm.

The in-plane retardation value R _e and the thickness direction retardation value R _th are respectively defined by the following equations.

R _e =(n _x -n _y )×d

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

For the zero-retardation film, for example, polyolefin-based resins such as cellulose-based resins, chain polyolefin-based resins, and cyclic polyolefin-based resins, polyethylene terephthalate-based resins, or (meth)acrylic-based resins can be used. Resin film made of resin. In particular, it is preferable to use a cellulose-based resin, a polyolefin-based resin, or a (meth)acrylic-based resin in terms of easy control of the retardation value and ease of acquisition.

Furthermore, as the retardation film, a film expressing optical anisotropy by coating/alignment of a liquid crystalline compound, and a film expressing optical anisotropy by coating an inorganic layered compound can also be used. This kind of retardation film includes what is called a temperature compensation type retardation film, or a film with rod-shaped liquid crystals sold under the trade name "NH FILM" by JX Nippon Oil & Energy Co., Ltd. Co., Ltd. sold under the trade name of "WV FILM" as a tilt-alignment film for discotic liquid crystals, and a completely biaxially-aligned film sold under the trade name of "VAC FILM" by Sumitomo Chemical Co., Ltd. A biaxially aligned film and the like sold under the trade name "new VAC FILM" by Sumitomo Chemical Co., Ltd. Moreover, the resin film layered on at least one surface of the retardation film may be, for example, the aforementioned protective film.

[3] Optical laminates

The present invention includes an optical laminate, which is a substrate comprising the above-mentioned optical film with an adhesive layer, and an adhesive layer on the side of the optical film with an adhesive layer. The optical laminate of the present invention has excellent durability even under severe durability conditions (for example, durability conditions above 100° C.) because the adhesive layer is formed of the aforementioned adhesive composition.

The substrate can be a conventional substrate, such as a glass substrate, an ITO (tin-doped indium oxide) substrate, a plastic film, an organic conductive film, a metal layer, an overcoat resin layer, and the like.

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

The optical laminated body 5 shown in FIG. 4 is to laminate the metal layer 30 (or the metal wiring layer 30) laminated on the substrate 40 on the optical film 1a with the adhesive layer (or the polarizing plate 1a with the adhesive layer). ) on the side of the adhesive layer. The aforementioned optical film 1a with an adhesive layer is one in which an adhesive layer 20 is layered on the polarizer 2 side of the aforementioned polarizer 10a.

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

The optical layered bodies 5 and 6 can be obtained by bonding the optical film ( 1 a , 1 b ) with an adhesive layer to the metal layer 30 laminated on the substrate 40 via the adhesive layer 20 .

The method of forming the metal layer 30 on the substrate 40 may, for example, be sputtering or the like. The substrate 40 can be a transparent substrate constituting the liquid crystal unit contained in the touch input element, preferably a glass substrate. As the material of the glass substrate, soda-lime glass, low-alkali glass, non-alkali glass, etc. can be used. The metal layer 30 may be formed on the entire surface of the substrate 40 or may be formed on a part of the substrate 40 .

For example, the metal layer 30 may contain at least one metal element selected from aluminum, copper, silver, iron, tin, zinc, nickel, molybdenum, chromium, tungsten, lead, and an alloy containing two or more of these metals. Floor. From the viewpoint of conductivity, among these, a layer containing at least one metal element selected from aluminum, copper, silver, and gold is preferable, and a layer containing at least one metal element selected from the viewpoint of conductivity and cost is more preferable. The layer of aluminum element is more preferably a layer containing aluminum element as a main component (50% by mass or more of all metal components constituting the metal layer 30 ).

The metal layer 30 can be, for example, a transparent electrode layer such as ITO, and can have the metal layer 30 and a transparent electrode layer made of metal oxides such as ITO at the same time. Also, a metal mesh in which a fine-wire metal wiring layer is arranged on a substrate, and a layer in which metal nanoparticles and metal nanowires are added to an adhesive can also be used.

The preparation method of the metal layer 30 is not particularly limited, it can be a metal foil, and can also be formed by vacuum evaporation, sputtering, ion plating, inkjet printing, gravure printing, but preferably It is a metal layer formed by a sputtering method, an inkjet printing method, or a gravure printing method, more preferably a metal layer formed by a sputtering method. The thickness of the metal layer 30 is not particularly limited, but it 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. Also, when the metal layer 30 is a metal wiring layer (such as a metal mesh), the line width of the metal wiring is usually 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and usually 0.5 μm or more.

The optical layered body 7 shown in FIG. 6 is one in which the adhesive layer 20 of the optical film 1 with the aforementioned adhesive layer is laminated on the substrate 40 .

In the optical laminate 8 shown in FIG. 7, a resin layer 50 is laminated on the surface of the substrate 40 on which the metal layer 30 is laminated (the surface opposite to the substrate 40), and the laminated resin layer 50 is further laminated. On the surface of the adhesive layer 20 side of the optical film 1 with the adhesive layer attached. The resin forming the resin layer 50 may, for example, be the resin constituting the first or second resin film exemplified above.

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

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

After pasting the optical film (1, 1a, 1b) with the adhesive layer on the substrate 40 (glass substrate, transparent substrate, etc.) or the metal layer 30 (transparent electrode layer) to make an optical laminate, if there is any defect, It is necessary to perform so-called heavy work, that is, to peel off the optical film 1 with the adhesive layer from the substrate 40 or the metal layer 30 and reattach the other optical film 1 with the adhesive layer to the substrate 40 or the metal layer 30 . The optical film 1 with an adhesive layer of the present invention is not easy to produce blurring, adhesive residue, etc. on the surface of the peeled glass substrate or transparent electrode, and is excellent in reworkability.

[4] Image display device

The adhesive layer, the optical film with the adhesive layer, and the optical laminate of the present invention can be used in image display devices such as liquid crystal display devices and organic EL display devices, and the image display devices have excellent durability.

The liquid crystal display device may be a touch input type liquid crystal display device with a touch panel function. The touch input liquid crystal display device is provided with a touch input element including a liquid crystal unit and a backlight. The composition of the touch panel can be a known method (such as Out-cell type, On-cell type, In-cell type, etc.), and the operation method of the touch panel can be a known method, such as a resistive film method, an electrostatic capacity method (surface type capacitance method, projected type capacitance method), etc. The optical film with an adhesive layer of the present invention can be arranged on the viewing side of the touch input element (liquid crystal unit), or on the backlight side, or on both the viewing side and the backlight side. The driving method of the liquid crystal cell may be any conventionally known method such as TN method, VA method, IPS method, multi-domain method, OCB method or the like. In addition, in the aforementioned liquid crystal display device, the substrate 40 having the optical laminate may be a substrate (typically a glass substrate) included in the aforementioned liquid crystal cell.

Moreover, the optical film with the adhesive layer of the present invention can be disposed on the viewing side of the organic EL display device.

An organic EL display device, for example, may have the following structure: In each pixel formed on the substrate, counting from the substrate side, the organic EL layer at the portion where the lower electrode and the material having an optical effect start to operate is laminated, and the upper electrode. Light from the organic EL that emits light by passing a current through the organic EL layer is recognized through at least one of the electrodes (light-transmitting conductive film).

[5] (Meth)acrylic resin for adhesive composition (A)

The present invention includes a (meth)acrylic resin (A) for an adhesive composition. The (meth)acrylic resin (A) for the adhesive composition is the same as the above-mentioned (meth)acrylic resin (A), and constitutes a preferable structural unit of the (meth)acrylic resin (A) and the The preferable ratio etc. of a structural unit are also the same as that of the said (meth)acrylic-type resin (A). Furthermore, it is preferable that this (meth)acrylic-type resin (A) for adhesive agent compositions is the (meth)acrylic-type resin for adhesive agent compositions which can be used for the optical film with an adhesive agent layer. Moreover, the adhesive composition to which the (meth)acrylic-type resin (A) for adhesive compositions is applied is not specifically limited, Preferably, the adhesive composition as described in said [1] is mentioned.

In a preferred aspect of the present invention, the (meth)acrylic resin (A) for the adhesive composition contains a structural unit derived from (meth)acrylate (a1) containing an acetoacetyl group, and A structural unit derived from a hydroxyl group-containing (meth)acrylate (a2), the mass ratio (a2)/(a1) of the aforementioned structural unit is 0.5 to 5, and the weight average molecular weight (Mw) is More than 1 million. The (meth)acrylic resin (A) used in such an adhesive composition can form an adhesive layer having excellent durability and good reworkability even in a high temperature environment (for example, a high temperature environment of 100° C. or higher).

(Example)

The present invention will be described in more detail below with examples and comparative examples, but the present invention is not limited to these examples. The usage amount, content and % are shown below as the quality basis.

<Production example 1: Production of (meth)acrylic resin (A-1) for adhesive layer>

In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, add the monomers of the composition shown in Table 1 (the values in Table 1 are parts by mass) and 80 parts of ethyl acetate, 40 parts of acetone, azobis The resulting solution was mixed with 0.012 parts of isobutyronitrile. After replacing the air in the reaction vessel with nitrogen, the inner temperature was raised and reacted at reflux temperature for 3.5 hours, then ethyl acetate was added to adjust the concentration of the polymer to 20%, and the (meth)acrylic resin (meth)acrylic resin ( A-1) ethyl acetate/acetone solution. The weight average molecular weight Mw of the obtained (meth)acrylic resin (A-1) was 1.39 million, and the ratio (Mw/Mn) of the weight average molecular weight Mw and the number average molecular weight Mn was 3.9.

<Manufacture Example 2-14: Manufacture of (meth)acrylic resin (A-2 to 14) for adhesive layer>

Ethyl acetate/acetone solutions (resin concentration: 20%) of (meth)acrylic resins (A-2 to 14) were obtained in the same manner as Production Example 1 except that the monomer composition was the composition shown in Table 1. The weight average molecular weight Mw of the obtained (meth)acrylic resins (A-2 to 14) is in the range of 1.3 million to 1.5 million, and the Mw/Mn is in the range of 3 to 6.

In the above production examples, the weight average molecular weight Mw and the number average molecular weight Mn are high-speed liquid chromatography (manufactured by Waters Corporation of Japan, "Waters 2695 (body)" and "Waters 2414 (detector)") with a column: Shodex GPC KF-806L (exclusion limit molecular weight: 2×10 ⁷ , separation range: 100 to 2×10 ⁷ , number of theoretical segments: 10,000 segments/branch, filler material: styrene/divinylbenzene copolymer, filler particles Diameter: 10μm) were arranged in series, using tetrahydrofuran as the eluent, the sample concentration was 1mg/mL, the sample introduction volume was 100μL, the temperature was 35°C, and the flow rate was 1mL/min. The conditions were measured by standard polystyrene conversion. The conditions for obtaining the efflux curve of GPC are also the same.

The glass transition temperature Tg is measured using a differential scanning calorimeter (DSC) "EXSTAR DSC6000" manufactured by SII NanoTechnology Co., Ltd. under a nitrogen atmosphere with a temperature range of -80 to 50°C and a heating rate of 10°C/min. .

Table 1 shows the composition of monomers in each production example (the values in Table 1 are parts by mass), and the weight average molecular weight and molecular weight distribution (Mw/Mn) of the obtained (meth)acrylic resin.

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

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

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

AAEM: Acetylacetyloxyethyl methacrylate (a1)

HEA: 2-hydroxyethyl acrylate (a2)

PEA: Phenoxyethyl Acrylate

PEA2: Phenoxydiethylene glycol acrylate

BMAA: Butoxymethacrylamide

AA: Acrylic

<Examples 1 to 9, Comparative Examples 1 to 7>

(1) Preparation of adhesive composition

In the ethyl acetate solution (resin concentration: 20%) of the (meth)acrylic resin obtained in the above production example, mix the amount (parts by mass) shown in Table 2 with respect to 100 parts of the solid content of the solution. To the joint agent (B) and the silane compound (C), ethyl acetate was further added so that the solid content concentration became 14%, and an adhesive composition was obtained. When the product used contains solvents, etc., the compounding amount of each compounding ingredient shown in Table 2 is the mass part of the active ingredient contained therein.

In Table 2, each compounded component indicated by the abbreviation is as follows in detail.

(crosslinking agent)

B-1: Ethyl acetate solution of trimethylolpropane adduct of methylenediisocyanate (solid content concentration: 75%), trade name "CORONATE L" obtained from Tosoh Co., Ltd.

(silane compound)

C-1: 1,6-bis(trimethoxysilyl)hexane.

(2) Production of adhesive layer

Using an applicator, apply each of the adhesive compositions prepared in the above (1) to a thickness of 20 μm after drying on the separator made of a polyethylene terephthalate film that has been subjected to mold release treatment. The release-treated surface of the film [trade name "PLR-382051" obtained from Lintec Co., Ltd.] was dried at 100° C. for 1 minute to prepare an adhesive layer (adhesive sheet).

(3) Preparation 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 VF-PE#6000" manufactured by Kuraray Co., Ltd.] was immersed in pure water at 37°C, and the Immerse in an aqueous solution of iodine and potassium iodide (iodine/potassium iodide/water (mass ratio)=0.04/1.5/100) at 30°C. Thereafter, it was immersed at 56.5° C. in an aqueous solution (potassium iodide/boric acid/water (mass ratio)=12/3.6/100) containing potassium iodide and boric acid. After the film was washed with pure water at 10°C, it was dried at 85°C to obtain a polarizer having a thickness of about 23 μm in which iodine was adsorbed and aligned on polyvinyl alcohol. The extension was mainly carried out in the steps of iodine staining and boric acid treatment, and the total extension ratio was 5.3 times.

A transparent protective film made of cellulose triacetate film with a thickness of 25 μm [trade name manufactured by KONICA MINOLTA OPTO Co., Ltd. "KC2UA"]. Next, on the surface of the polarizer opposite to the cellulose triacetate film, a zero point made of cyclic polyolefin-based resin with a thickness of 23 μm was pasted via an adhesive made of polyvinyl alcohol-based resin aqueous solution. A phase difference film [trade name "ZEONOR" manufactured by Japan ZEON Co., Ltd.] was used to make a polarizing plate. Next, after performing corona discharge treatment for improving the adhesion on the surface of the zero-retardation film opposite to the surface connected to the polarizer, the adhesive layer made in the above (2) is separated from the separation film. The opposite side (adhesive layer) was bonded by a laminator, and then cured for 7 days at a temperature of 23°C and a relative humidity of 65%, to obtain an optical film (P-1) with an adhesive layer.

(4) Durability evaluation of optical film with adhesive layer

Cut the optical film (P-1) with the adhesive layer produced in the above (3) into a size of 300mm×220mm in such a way that the extending axis direction of the polarizing plate becomes the long side, and peel off the separation film, and the exposed adhesive The layer is attached to the glass substrate. The obtained test piece attached to the glass substrate (optical film with an adhesive layer attached to the glass substrate) was pressurized in an autoclave at a temperature of 50° C. and a pressure of 5 kg/cm ² (490.3 kPa) for 20 minutes. The glass substrate is an alkali-free glass manufactured by Corning Corporation, and its trade name is "Eagle XG".

The obtained optical layered body was subjected to a heat resistance test in which it was kept under dry conditions at a temperature of 105° C. for 250 hours.

Visually observe the optical laminate after each test, and visually observe whether the adhesive layer has any appearance changes such as floating, peeling, and foaming, and evaluate the durability according to the following evaluation criteria. The results are shown in Table 3.

5: Changes in appearance such as floating, peeling, and foaming were not observed at all.

4: Changes in appearance such as floating, peeling, and foaming were hardly observed.

3: Changes in appearance such as floating, peeling, and foaming are slightly observed.

2: Appearance changes such as floating, peeling, and foaming are observed.

1: Appearance changes, such as floating, peeling, and foaming, were clearly recognized.

(5) Adhesion evaluation of optical film with adhesive layer

Cut the optical film (P-1) with the adhesive layer produced in (3) above into a test piece with a size of 25mm×150mm. The separator sheet was peeled off from the test piece, and the adhesive surface was attached to the glass substrate. The obtained test piece attached to the glass substrate (optical film with an adhesive layer attached to the glass substrate) was pressurized at a temperature of 50°C and a pressure of 5kg/cm ² (490.3kPa) for 20 minutes in an autoclave. After storing in an environment with a temperature of 23°C and a relative humidity of 50% for 24 hours, the optical film and the adhesive layer were peeled off from the test piece 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 the adhesive force. When the adhesive force is 15 N or less, it is excellent in reworkability, and when it is 0.5 N or more, peeling is less likely to occur when impact is received from the end of the polarizing plate.

[ITO corrosion evaluation of optical laminates]

The surface resistance (surface resistance value before the test) of the surface of the ITO layer of the glass substrate with the ITO layer was measured with a low resistivity meter [trade name "Loresta-AX" manufactured by Mitsubishi Chemical Analytech Co., Ltd.]. Next, the polarizing plate on which the adhesive layer produced in (3) above was formed was cut into a test piece having a size of 20 mm×40 mm. The separator sheet was peeled off from the obtained test piece, and it stuck to the ITO layer side of the glass substrate through the adhesive layer. The obtained optical laminate was stored in an oven at a temperature of 60°C and a relative humidity of 90% for 500 hours, and then the ITO layer and the adhesive layer were peeled off in an environment of a temperature of 23°C and a relative humidity of 50%. The surface resistance of the ITO layer after peeling was measured (surface resistance value after test). Calculate the resistance change rate before and after the test with the following formula and evaluate it with the following criteria. The smaller the resistance change rate, the lower the corrosion resistance of ITO. The results are shown in Table 3.

Resistance change rate (%)=[(surface resistance value after test)-(surface resistance value before test)]/[surface resistance value before test]×100

<Evaluation criteria for ITO corrosivity>

○: The resistance change rate is less than 50%, and it is an optical laminate with good corrosion resistance of ITO.

×: The resistance change rate is more than 50%, and the ITO corrosion of the optical laminate is poor.

〔Gelation rate of adhesive sheet〕

The method for evaluating the gelation rate of the adhesive sheet of the present invention is described. The greater the gelation rate, the more cross-linking reactions in the adhesive, which can be used as the basis for judging the cross-linking density. The gelation rate is the value measured according to the following (a) to (d).

(a) Bond an adhesive sheet with an area of about 8 cm x about 8 cm to a metal mesh (the mass of which is Wm) made of SUS304 about 10 cm x about 10 cm.

(b) Weigh the laminate obtained in (1) above, and set its mass as Ws, then fold it 4 times by wrapping the adhesive sheet and fix it with a stapler, then weigh it, and set its mass as Wb.

(c) Put the net fixed with a stapler in the above (2) into a glass container, add 60 mL of ethyl acetate and dip it, and store the glass container at room temperature for 3 days.

(d) Take out the net from the glass container, dry it at 120°C for 24 hours, weigh it, set its mass as Wa, and calculate the gelation rate according to the following formula.

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

As shown in Table 3, the optical components of Examples 1 to 9 in which the mass ratio (a2)/(a1) of AAEM (a1) to HEA (a2) in the (meth)acrylic resin component is in the range of 0.5 to 5 The layered system exhibited superior durability compared to the optical layered bodies of Comparative Examples 1 to 7 in which the mass ratio was out of the range of 0.5 to 5. Furthermore, among the (meth)acrylic resin components, the optical laminate system of Example 4 containing 0.1 parts by mass of AA and Example 5 containing 0.5 parts by mass of BMAA showed more excellent durability.

<Production Example 15-17: Production of (meth)acrylic resins (A-15) to (A-17) for adhesive layer>

Except that the composition of the monomer is the composition shown in Table 4, the ethyl acetate/acetone solution (resin concentration: 20%). The weight average molecular weights Mw of the obtained (meth)acrylic resins (A-15) to (A-17) are all in the range of 1.1 million to 1.5 million, and the Mw/Mn is in the range of 3 to 6. The weight average molecular weight Mw and the number average molecular weight Mn are measured by the method described above.

The abbreviations in the "monomer composition" column of Table 4 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)

AAEM: Acetylacetyloxyethyl methacrylate (a1)

HEA: 2-hydroxyethyl acrylate (a2)

PEA: Phenoxyethyl Acrylate

PEA2: Phenoxydiethylene glycol acrylate

BMAA: Butoxymethacrylamide

AA: Acrylic

<Example 10-12>

(6) Preparation of adhesive composition

In the ethyl acetate solution (resin concentration: 20%) of the (meth)acrylic resin obtained in the above-mentioned Production Examples 15-17, mix 100 parts relative to the solid content of the solution in the amount shown in Table 5 (parts by mass) To the crosslinking agent (B) and silane compound (C), ethyl acetate was further added so that the solid content concentration became 14%, and an adhesive composition was obtained. When the product used contains a solvent, etc., the compounding amount of each compounding ingredient shown in Table 5 is the mass part of the active ingredient contained therein.

In Table 5, each compounding component indicated by the abbreviation is described in detail as follows.

(crosslinking agent)

B-1: Ethyl acetate solution of trimethylolpropane adduct of methylenediisocyanate (solid content concentration: 75%), trade name "CORONATE L" obtained from Tosoh Co., Ltd.

(silane compound)

C-1: 1,6-bis(trimethoxysilyl)hexane.

(7) Production of adhesive layer

The adhesive layer (adhesive sheet) was prepared in the same manner as in the above "(2) Preparation of the adhesive layer" except that the adhesive composition prepared in the above (6) was used instead of the adhesive composition.

(8) Preparation of optical film (P-2) with adhesive layer

Except for replacing the adhesive layer with the adhesive layer prepared in the above (7), the optical film with the adhesive layer is produced in the same way as the above "(3) Production of the optical film with the adhesive layer (P-1)". Film (P-2).

(9) Durability evaluation of optical film with adhesive layer

Cut the optical film (P-2) with the adhesive layer produced in the above (8) into a size of 300mm×220mm in such a way that the extending axis direction of the polarizing plate becomes the long side, peel off the separation film, and expose the adhesive The layer is attached to the glass substrate. The obtained test piece attached to the glass substrate (optical film with an adhesive layer attached to the glass substrate) was pressurized at a temperature of 50°C and a pressure of 5kg/cm ² (490.3kPa) for 20 minutes in an autoclave. The glass substrate is an alkali-free glass manufactured by Corning Corporation, and its trade name is "Eagle XG".

The obtained optical layered body was subjected to a heat resistance test in which it was kept under dry conditions at a temperature of 105° C. for 500 hours.

Visually observe the optical laminate after each test, and visually observe whether the adhesive layer has any appearance changes such as floating, peeling, and foaming, and evaluate the durability according to the evaluation criteria. The results are shown in Table 6.

5: Changes in appearance such as floating, peeling, and foaming were not observed at all.

4: Changes in appearance such as floating, peeling, and foaming were hardly observed.

3: Changes in appearance such as floating, peeling, and foaming are slightly observed.

2: Appearance changes such as floating, peeling, and foaming are observed.

1: Appearance changes, such as floating, peeling, and foaming, were clearly recognized.

(10) Adhesion evaluation of optical film with adhesive layer

In addition to replacing the optical film with the adhesive layer with the optical film with the adhesive layer (P-2) produced in the above (8), it is evaluated by the adhesion with the above "(5) Optical film with the adhesive layer" The same method was used to evaluate the adhesion of the optical film (P-2) with the adhesive layer attached. The results are shown in Table 6.

[ITO corrosion evaluation of optical laminates]

Except for replacing the optical film with the adhesive layer with the optical film (P-2) prepared in (8) above, an optical laminate with ITO laminated was produced in the same manner as described above, and The ITO corrosion property of the optical layered body obtained by the method described above was evaluated. The results are shown in Table 6. In addition, the evaluation criteria are also the same as above.

[Gelation rate of adhesive sheet]

The gelation rate of the adhesive sheet prepared in (7) above was measured by the method described above. The results are shown in Table 6.

As shown in Table 6, the examples in which the mass ratio (a2)/(a1) of AAEM (a1) to HEA (a2) in the components of the (meth)acrylic resin is in the range of 0.5 to 5 show a higher ratio than the mass ratio (a2)/(a1). Excellent durability of the optical layered body of the comparative example whose ratio is out of the range of 0.5 to 5. Furthermore, in the (meth)acrylic resin component, if the ratio of the alkyl acrylate (a3) whose glass transition temperature of the homopolymer is lower than 0°C contains more than the alkyl acrylate (a3) whose homopolymer Tg is 0°C or higher ( a4), it shows good durability even in a more severe durability test.

<Examples 13-15, Comparative Example 8>

(11) Preparation of adhesive composition

In the ethyl acetate solution (resin concentration: 20%) of the (meth)acrylic resin obtained in the above-mentioned production examples 2-4, 13, mix 100 parts relative to the solid content of the solution in the amount shown in Table 7 (mass Parts) of the crosslinking agent (B), silane compound (C) and ionic compound (D), and ethyl acetate was further added so that the solid content concentration became 14%, and an adhesive composition was obtained. When the product used contains a solvent, etc., the compounded amount of each compounded ingredient shown in Table 7 is the mass part of the active ingredient contained therein.

The details of each compounded component indicated by the abbreviation in Table 7 are as follows.

(crosslinking agent)

B-1: Ethyl acetate solution of trimethylolpropane adduct of methylenediisocyanate (solid content concentration: 75%), trade name "CORONATE L" obtained from Tosoh Co., Ltd.

(silane compound)

C-1: 1,6-bis(trimethoxysilyl)hexane.

(ionic compounds)

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

(12) Production of adhesive layer

The adhesive layer was prepared in the same manner as in the above "(2) Preparation of the adhesive layer" except that the adhesive composition prepared in the above (11) was used instead of the adhesive composition.

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

A polyvinyl alcohol film with an average degree of polymerization of 2400, a degree of saponification of 99.9 mol%, and a thickness of 30 μm (trade name [Kuraray poval-film VF-PE#3000] manufactured by Kuraray Co., Ltd.) was immersed in pure water at 37° C. Immerse in an aqueous solution of iodine and potassium iodide (iodine/potassium iodide/water (weight ratio)=0.04/1.5/100) at 30°C. Thereafter, it was immersed at 56.5° C. in an aqueous solution (potassium iodide/boric acid/water (weight ratio)=12/3.6/100) containing potassium iodide and boric acid. Next, the film was washed with pure water at 10° C., and then dried at 85° C. to obtain a polarizer A having a thickness of about 12 μm in which iodine was adsorbed and aligned on polyvinyl alcohol. The extension is mainly carried out in the steps of iodine staining and boric acid treatment, and the total extension ratio is 5.3 times.

On one side of the obtained polarizing film A, a transparent protective film obtained by attaching a 7 μm hard coat layer to a triacetyl cellulose film with a thickness of 25 μm via an adhesive composed of a polyvinyl alcohol-based resin aqueous solution (letter printing Co., Ltd. trade name [25KCHCN-TC]). Next, on the surface of the polarizing film A opposite to the surface on which the transparent protective film is pasted, a cycloolefin-based resin film with a thickness of 23 μm (Japan ZEON Co., Ltd. The product name [ZF14-023] manufactured by the company) was used to obtain a polarizing plate A. Next, corona discharge treatment is performed on the surface of the cycloolefin-based resin film on the opposite side to the contact surface of the polarizer to improve adhesion, and the adhesive layer prepared in the above (12) is bonded by a laminator. After the surface (adhesive layer) on the opposite side to the separation film was cured for 7 days at a temperature of 23°C and a relative humidity of 65%, an optical film (P-3) with an adhesive layer was obtained.

(14) Durability evaluation of optical film with adhesive layer

In addition to replacing the optical film with the adhesive layer with the optical film with the adhesive layer (P-3) produced in the above (13), the durability evaluation of the optical film with the adhesive layer in the above "(4) "The same method was used to evaluate the durability of the optical film with the adhesive layer attached. The results are shown in Table 8. In addition, the evaluation criteria are also the same as above.

(15) Adhesion evaluation of optical film with adhesive layer

In addition to replacing the optical film with the adhesive layer with the optical film with the adhesive layer produced in the above (13) (P-3), it is evaluated by the adhesion with the optical film with the adhesive layer in the above "(5) "The same method was used to evaluate the adhesion of the optical film (P-3) with the adhesive layer. The results are shown in Table 8.

[ITO corrosion evaluation of optical laminates]

Except for replacing the optical film with the adhesive layer with the optical film with the adhesive layer (P-3) prepared in (13) above, an optical laminate with ITO laminated was produced in the same manner as described above, And evaluate the ITO corrosivity of the optical layered body obtained by the method described above. The results are shown in Table 8. In addition, the evaluation criteria are also the same as above.

[Gelation rate of adhesive sheet]

The gelation rate of the adhesive sheet prepared in (12) above was measured by the method described above. The results are shown in Table 8.

After peeling off the separator of the optical film (P-3) with the adhesive layer produced in (13) above, the surface intrinsic resistance measurement device ["Hiresta-up MCP-HT450" manufactured by Mitsubishi Chemical Co., Ltd. ( Trade name)] to measure the surface resistance value of the adhesive. The measurement was carried out under the measurement conditions of an applied voltage of 250 V and an applied time of 10 seconds. When the surface resistance value is 1.0×10 ¹² Ω/□ or less, good antistatic property can be obtained.

1‧‧‧Optical film with adhesive layer

10‧‧‧optical film

20‧‧‧adhesive layer

Claims (23)

An adhesive composition, which contains (meth)acrylic resin (A), crosslinking agent (B) and silane compound (C); the aforementioned (meth)acrylic resin (A) is derived from Structural unit derived from (meth)acrylate (a1) of acyl acetyl group, structural unit derived from (meth)acrylate (a2) containing hydroxyl group, and (meth)acrylate derived from carboxyl group As for the constituent units, the mass ratio (a2)/(a1) of the aforementioned constituent units is 0.5 to 5. The adhesive composition according to claim 1, wherein the (meth)acrylic resin (A) has a weight average molecular weight of 1 million or more in terms of polystyrene. The adhesive composition as described in claim 1 or 2 of the patent application, wherein the (meth)acrylic resin (A) further comprises an alkyl acrylate derived from a homopolymer whose glass transition temperature does not reach 0°C ( The structural unit of a3) and the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more. The adhesive composition as described in claim 3, wherein the constituent unit derived from an alkyl acrylate (a3) whose glass transition temperature is less than 0°C of the homopolymer and the glass derived from the homopolymer The mass ratio (a3)/(a4) of the structural unit of the alkyl acrylate (a4) whose transition temperature is 0 degreeC or more is 0.1-4. The adhesive composition as described in claim 1 or 2 of the patent claims, wherein the (meth)acrylic resin (A) is Included from The ratio to the structural unit of the carboxyl group-containing (meth)acrylate is 1.0 parts by mass or less. The adhesive composition as described in claim 1 or 2, wherein the (meth)acrylic resin (A) further contains constituent units derived from (meth)acrylamide monomers. The adhesive composition as described in claim 1 or 2, wherein the crosslinking agent (B) is an isocyanate compound. The adhesive composition according to claim 1 or 2, wherein the ratio of the crosslinking agent (B) is 0.01 to 10 parts by mass relative to 100 parts by mass of the (meth)acrylic resin (A). The adhesive composition as described in item 1 or 2 of the scope of application, wherein the silane compound (C) is a silane compound represented by the following formula (c1);

In the formula, B represents an alkanediyl group with 3 to 20 carbons or a divalent alicyclic hydrocarbon group with 3 to 20 carbons, and the -CH ₂ - constituting the alkanediyl group and the alicyclic hydrocarbon group can be substituted with -O -or-CO-, R ¹ represents an alkyl group with 1 to 5 carbons, R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently represent an alkyl group with 1 to 5 carbons or an alkyl group with 1 to 5 carbons alkoxy. The adhesive composition as described in claim 1 or 2, wherein the ratio of the silane compound (C) is 0.01 to 10 parts by mass relative to 100 parts by mass of the (meth)acrylic resin (A). The adhesive composition as described in item 1 or 2 of the scope of the patent application, which It does not contain a photopolymerization initiator and its decomposition product substantially. The adhesive composition as described in item 1 or 2 of the claims further contains an ionic compound (D). The adhesive composition according to claim 12, wherein the ratio of the ionic compound (D) is 0.01 to 10 parts by mass relative to 100 parts by mass of the (meth)acrylic resin (A). The adhesive composition as described in claim 12 of the patent application, wherein the anion constituting the ionic compound (D) is bis(trifluoromethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, bis(fluorosulfonyl)acyl At least one selected from the group consisting of iminium anion and tetrakis(pentafluorophenyl)borate anion. An adhesive layer containing the adhesive composition described in any one of items 1 to 14 of the patent application. The adhesive layer described in claim 15, wherein the gelation rate of the aforementioned adhesive layer is 70 to 90%. An optical film with an adhesive layer, comprising an optical film and an adhesive layer on at least one surface of the optical film, and the adhesive layer is the adhesive layer described in claim 15 or 16 of the patent application. An optical laminate comprising the optical film with an adhesive layer described in claim 17 of the patent application, and a substrate laminated on the side of the adhesive layer of the optical film with an adhesive layer. A (meth)acrylic resin (A) for an adhesive composition, comprising a structural unit derived from (meth)acrylate (a1) containing acetoacetyl group, derived from (meth)acrylic acid ester (a1) containing hydroxyl group group) a structural unit of acrylate (a2), and a structural unit derived from a carboxyl group-containing (meth)acrylate, The mass ratio (a2)/(a1) of the aforementioned constituent units is 0.5 to 5, and the weight average molecular weight is 1 million or more in terms of polystyrene. The (meth)acrylic resin (A) for an adhesive composition as described in claim 19, wherein the (meth)acrylic resin (A) further includes a glass transition temperature derived from a homopolymer The structural unit of the alkyl acrylate (a3) which is less than 0 degreeC, and the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more. The (meth)acrylic resin (A) for an adhesive composition as described in claim 20, wherein the alkyl acrylate (a3) derived from a homopolymer whose glass transition temperature does not reach 0°C The mass ratio (a3)/(a4) of a structural unit to the structural unit derived from the alkyl acrylate (a4) whose glass transition temperature of a homopolymer is 0 degreeC or more is 0.1-4. The (meth)acrylic resin (A) for an adhesive composition as described in claim 19 or 20, wherein, relative to 100 parts by mass of all structural units constituting the (meth)acrylic resin (A) , The ratio of the structural unit derived from the carboxyl group-containing (meth)acrylate contained in (meth)acrylic-type resin (A) is 1.0 mass parts or less. The (meth)acrylic resin (A) for an adhesive composition as described in claim 19 or 20, wherein the (meth)acrylic resin (A) further contains Amide is the constituent unit of the monomer.

Images