WO2016010140A1 - Adhesive composition and adhesive using same, and adhesive for polarizing plate - Google Patents

Abstract

　This adhesive composition contains an acrylic resin (A) obtained by polymerizing a polymerization component including a monomer (a1) containing a reactive functional group, and an acrylic resin (B) obtained by polymerizing a polymerization component not including a monomer containing a reactive functional group, the polymerization component of the acrylic resin (A) including 2.5-30 wt% of the monomer (a1) containing a reactive functional group, and the polymerization component of the acrylic resin (B) including a monomer (b1) containing a nonreactive polar functional group.

Description

Pressure-sensitive adhesive composition, pressure-sensitive adhesive using the same, and pressure-sensitive adhesive for polarizing plate

The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive using the same, and a pressure-sensitive adhesive for polarizing plates. More specifically, the pressure-sensitive adhesive is excellent in durability, light leakage resistance, reworkability, transparency, and antistatic properties. The present invention relates to a pressure-sensitive adhesive composition that forms a film, a pressure-sensitive adhesive using the same, and a pressure-sensitive adhesive for polarizing plates.

Conventionally, both sides of a polyvinyl alcohol film to which polarizing properties are imparted are protective films (generally, a triacetyl cellulose film, a film provided with acrylic, cycloolefin, olefin, retardation layer, etc.) For example, a polarizing plate coated with a triacetyl cellulose film is laminated on the surface of a liquid crystal cell in which an oriented liquid crystal component is sandwiched between two glass plates to form a liquid crystal display plate. The lamination on the cell surface is usually performed by bringing the pressure-sensitive adhesive layer provided on the polarizing plate surface into contact with the liquid crystal cell surface and pressing it.

Such a polarizing plate typically has a three-layer structure in which both surfaces of a polyvinyl alcohol-based polarizer are sandwiched between triacetyl cellulose-based protective films, but dimensional stability is poor due to the characteristics of these materials. In addition, since the polyvinyl alcohol-based polarizer is formed by stretching, dimensional changes are likely to occur due to the heat of the backlight over time and the heat and humidity from the environment.
If the stress caused by such a dimensional change cannot be absorbed and relaxed, the distribution of residual stress acting on the adhesive layer and the polarizing plate becomes non-uniform, and the stress is concentrated especially on the periphery of the polarizing plate. Light leakage may occur due to birefringence in the material or warpage of the liquid crystal cell, and if the adhesive has low durability, the stress generated may cause floating, peeling, foaming, etc. .

Therefore, regarding the adhesive for attaching a polarizing plate, in addition to being excellent in durability without foaming or peeling in a heat cycle from high temperature, high temperature and high humidity, low temperature to high temperature, light leakage resistance, reworkability, Research has been conducted in search of pressure-sensitive adhesives that are well-balanced in various properties such as antistatic properties and transparency.

As an adhesive for polarizing plates developed for such a purpose, for example,
Including 100 parts by mass of an acrylic resin (A) having a functional group, 100 to 500 parts by mass of an acrylic resin (B) having no functional group, a crosslinking agent (C), and a silane coupling agent (D),
A copolymer in which the acrylic resin (A) is a (meth) acrylic ester monomer (a) 100 parts by mass and a functional group-containing monomer (c) 0.1 to 5 parts by mass with a weight average molecular weight of 1 to 2.5 million The acrylic resin (B) is a polymer having a weight average molecular weight of 1,000,000 to 2,500,000 of the (meth) acrylic ester monomer (b) containing no functional group-containing monomer, and the monomer a and the monomer b And a pressure-sensitive adhesive composition for polarizing plates (see Patent Document 1), characterized in that the monomer composition is 90 mass% or more identical.
A (meth) acrylic copolymer containing an alkyl (meth) acrylic acid ester monomer having 1 to 12 carbon atoms of alkyl, a gel fraction of 10 to 55%, and an expansion ratio of 30 to 110 An acrylic pressure-sensitive adhesive for polarizing plates, wherein the sol eluted from the pressure-sensitive adhesive with ethyl acetate has a weight average molecular weight of 800,000 or more and a molecular weight distribution of 2.0 to 7.0. A composition (refer patent document 2) is mentioned.

Japanese Unexamined Patent Publication No. 2011-122104 Japan Special Table 2009-507255

However, in recent years, with the increase in the size of the image display device and the thinning of the member structure, the polarizing plate constituting the image display device also has a higher level of durability, light leakage resistance, reworkability, transparency, and antistatic properties. However, there is still room for improvement in durability in the techniques of Patent Documents 1 and 2 described above, and this is a test method under severe conditions, particularly in durability, and more practical. The problem remained in the durability performance in the heat cycle test suitable for.

Therefore, in the present invention, under such a background, when the polarizing plate and the glass substrate are bonded together, the pressure-sensitive adhesive exhibits excellent durability performance (particularly heat cycle performance), and further, light leakage resistance and reworkability. The purpose of the present invention is to provide an adhesive having excellent antistatic properties and transparency (compatibility).

However, as a result of intensive research in view of such circumstances, the present inventors blended an acrylic resin (A) containing a reactive functional group and an acrylic resin (B) containing no reactive functional group. In the type of pressure-sensitive adhesive composition, the content of reactive functional groups in the acrylic resin (A) containing reactive functional groups is increased more than usual, and further the acrylic resin (B) containing no reactive functional groups By containing a polar functional group, an adhesive having a good balance between durability and light leakage resistance can be obtained, and the reactive functional group-containing acrylic resin (A) does not contain a reactive functional group. It has been found that a pressure-sensitive adhesive composition excellent in compatibility with the acrylic resin (B) can be obtained, and the present invention has been completed.

That is, the present invention includes the following aspects (1) to (11).
(1) Acrylic resin (A) obtained by polymerizing a polymerization component containing a reactive functional group-containing monomer (a1), and an acrylic resin (B) obtained by polymerizing a polymerization component containing no reactive functional group-containing monomer In which the polymerization component of the acrylic resin (A) contains 2.5 to 30% by weight of the reactive functional group-containing monomer (a1), and the acrylic resin (B) The polymerization component comprises a non-reactive polar functional group-containing monomer (b1).
(2) The pressure-sensitive adhesive according to (1), wherein the content of the non-reactive polar functional group-containing monomer (b1) in the polymerization component of the acrylic resin (B) is 0.1 to 30% by weight. Agent composition.
(3) The adhesive according to (1) or (2), wherein the reactive functional group-containing monomer (a1) is at least one selected from the group consisting of a hydroxyl group-containing monomer and a carboxyl group-containing monomer. Agent composition.
(4) The nonreactive polar functional group-containing monomer (b1) is at least one selected from the group consisting of an amide group-containing monomer, a tertiary amino group-containing monomer, and an ether group-containing monomer ( The pressure-sensitive adhesive composition according to any one of 1) to (3).
(5) The pressure-sensitive adhesive composition as described in any one of (1) to (4) above, wherein the acrylic resin (A) has a weight average molecular weight of 1,000,000 or more.
(6) The pressure-sensitive adhesive composition as described in any one of (1) to (5) above, wherein the acrylic resin (B) has a weight average molecular weight of 1,000,000 or more.
(7) The content ratio [(A) :( B)] (weight ratio) of the acrylic resin (A) and the acrylic resin (B) is (A) :( B) = 100: 50 to 100: 500 The pressure-sensitive adhesive composition as described in any one of (1) to (6) above, wherein
(8) The pressure-sensitive adhesive composition as described in any one of (1) to (7) above, which contains a crosslinking agent (C).
(9) The pressure-sensitive adhesive composition as described in (8) above, wherein the crosslinking agent (C) is at least one selected from the group consisting of an isocyanate crosslinking agent and an epoxy crosslinking agent.
(10) A pressure-sensitive adhesive obtained by crosslinking the pressure-sensitive adhesive composition according to any one of (1) to (9) with a crosslinking agent (C).
(11) A pressure-sensitive adhesive for polarizing plates comprising the pressure-sensitive adhesive according to (10).

The pressure-sensitive adhesive obtained using the pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive exhibiting excellent durability performance (particularly heat cycle resistance), and is excellent in adhesion between an optical member such as a polarizing plate and a glass substrate. A liquid crystal display device in which foaming or peeling does not occur between the pressure-sensitive adhesive layer and the glass substrate can be obtained.
Furthermore, the pressure-sensitive adhesive is excellent not only in durability but also in light leakage resistance and reworkability in a well-balanced manner, and is excellent in transparency because of excellent compatibility between blended acrylic resins.

The present invention is described in detail below.
In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate. The acrylic resin is a resin obtained by polymerizing a polymerization component containing at least one (meth) acrylate monomer.

The monomer in the present invention is a compound having a polymerizable unsaturated group, and the functional group of the monomer does not contain such a polymerizable unsaturated group.

First, the acrylic resin (A) and the acrylic resin (B) contained as essential components in the pressure-sensitive adhesive composition of the present invention will be described.

The acrylic resin (A) is obtained by polymerizing a polymerization component containing 2.5 to 30% by weight of the reactive functional group-containing monomer (a1). If necessary, the (meth) acrylic acid alkyl ester type The monomer (a2) or other copolymerizable ethylenically unsaturated monomer (a3) may be included as a copolymerization component.

The reactive functional group in the reactive functional group-containing monomer (a1) is reactive with a crosslinking agent (C) described below under general crosslinking reaction conditions (for example, 60 ° C. or less under no catalyst). The reactive functional group-containing monomer (a1) can be cross-linked when the acrylic resin (A) reacts with the cross-linking agent (C). It is a monomer containing a functional group that can become a point.

Specific examples of the reactive functional group-containing monomer (a1) include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, an acetoacetyl group-containing monomer, an isocyanate group-containing monomer, and a glycidyl group-containing monomer. Among these, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferable in that a crosslinking reaction can be efficiently performed with various crosslinking agents.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl ( Hydroxyalkyl esters of acrylic acid such as (meth) acrylate, caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth) acrylate, oxyalkylene-modified monomers such as diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, etc. Primary hydroxyl group-containing monomers such as acryloyloxyethyl-2-hydroxyethylphthalic acid, N-methylol (meth) acrylamide, and hydroxyethylacrylamide Secondary hydroxyl group-containing monomers such as 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate; 2,2-dimethyl 2-hydroxyethyl (meth) acrylate And a tertiary hydroxyl group-containing monomer.

Among the above hydroxyl group-containing monomers, a primary hydroxyl group-containing monomer is preferable from the viewpoint of excellent reactivity with a crosslinking agent, and a monomer having a hydroxyl group at the molecular chain end is preferable because it exhibits better antistatic performance. Furthermore, it is particularly preferable to use 2-hydroxyethyl acrylate because it has few impurities such as di (meth) acrylate and is easy to produce.

In addition, as a hydroxyl-containing monomer used by this invention, it is also preferable to use a thing with the content rate of di (meth) acrylate which is an impurity 0.5% or less, and also 0.2% or less, especially 0 It is preferable to use those having a content of 1% or less, and specifically, 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate are preferable.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, and cinnamon. An acid etc. are mentioned, Among these, (meth) acrylic acid is used preferably.

Examples of the acetoacetyl group-containing monomer include 2- (acetoacetoxy) ethyl (meth) acrylate and allyl acetoacetate.

Examples of the isocyanate group-containing monomer include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and alkylene oxide adducts thereof.

Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl (meth) acrylate.

These reactive functional group-containing monomers (a1) may be used alone or in combination of two or more. Among these, it is preferable to use a hydroxyl group-containing monomer and a carboxyl group-containing monomer in combination in terms of excellent reactivity with a crosslinking agent and storage stability.
When a hydroxyl group-containing monomer and a carboxyl group-containing monomer are used in combination, the proportion of the carboxyl group-containing monomer is preferably larger than that of the hydroxyl group-containing monomer because the content ratio is excellent in durability.

The content of the reactive functional group-containing monomer (a1) needs to be 2.5 to 30% by weight, preferably 3 to 25% by weight, particularly preferably 3 to It is 20% by weight, more preferably 3.5 to 15% by weight.
When the content of the reactive functional group-containing monomer (a1) is too large, the reworkability is lowered, the stress relaxation property is lowered, the light leakage resistance is deteriorated, the substrate is easily warped, and the amount is too small. And durability will fall.

As the above (meth) acrylic acid alkyl ester monomer (a2), for example, the alkyl group usually has 1 to 20, preferably 1 to 18, particularly preferably 1 to 12, and more preferably 1 to 8 carbon atoms. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-propyl (Meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) ) Acrylate, etc. These may be used alone or in combination of two or more.

Of these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferred from the viewpoint of versatility and adhesive properties, and these monomers are the main components. It is preferable to make it.

The content of the (meth) acrylic acid alkyl ester monomer (a2) is preferably 40 to 97% by weight, particularly preferably 50 to 95% by weight, more preferably 60 to 95% by weight, based on the entire polymerization component. It is.
If the content is too small, the resin price tends to increase and the balance of adhesive properties tends to be difficult to balance. If the content is too large, the cohesive force tends to decrease and the light leakage resistance tends to decrease.

Examples of the other copolymerizable ethylenically unsaturated monomer (a3) include:
Aromatic ring-containing monomers such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, and orthophenylphenoxyethyl (meth) acrylate;
Cyclohexyl (meth) acrylate, cyclohexyloxyalkyl (meth) acrylate, t-butylcyclohexyloxyethyl (meth) acrylate isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyl (meth) Alicyclic monomers such as acrylate and isobornyl (meth) acrylate;
Alkoxyalkyl such as methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, isopropoxymethyl (meth) acrylamide, n-butoxymethyl (meth) acrylamide, isobutoxymethyl (meth) acrylamide ( Amide monomers such as (meth) acrylamide monomers, (meth) acryloylmorpholine, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, (meth) acrylamide N-methylol (meth) acrylamide and other (meth) acrylamide monomers;
2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-butoxydiethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) Acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, octoxypolyethylene glycol-polypropylene glycol-mono (meth) acrylate, Lauro Xylethylene glycol mono (meth) acrylate, stearoxypolyethylene glycol mono (meth) acrylate Ether chains containing over preparative like (meth) acrylic acid ester monomer;
Acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl ether, vinyl toluene, vinyl pyridine, vinyl pyrrolidone, itaconic acid dialkyl ester, fumaric acid dialkyl ester, allyl alcohol, acrylic chloride Methyl vinyl ketone, N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallylvinylketone, and the like. These may be used alone or in combination of two or more.

Among these, an aromatic ring-containing monomer is preferable in terms of easy adjustment of refractive index and birefringence, and benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, and phenoxydiethylene glycol (meth) acrylate are particularly preferable. In terms of easy adjustment of refractive index and birefringence, and excellent adhesion to a low-polar adherend (olefin substrate), alicyclic monomers are preferred, and adhesion to substrates and adherends is preferred. In terms of easy adjustment of cohesive strength and resin compatibility, amide monomers are preferred.

The content of the other copolymerizable ethylenically unsaturated monomer (a3) is preferably 0 to 50 with respect to the entire polymerization component when (a3) is an aromatic ring-containing monomer or an alicyclic ring-containing monomer. % By weight, particularly preferably 5 to 40% by weight, more preferably 10 to 30% by weight. When the content is too large, it is difficult to adjust the birefringence, and the light leakage suppressing effect tends to decrease.

When (a3) is other than an aromatic ring-containing monomer or an alicyclic ring-containing monomer, it is preferably 0 to 10% by weight, particularly preferably 0 to 5% by weight, based on the entire polymerization component. When there is too much this content, there exists a tendency for the long-term storage stability of acrylic resin (A) to fall, or to gelatinize easily at the time of superposition | polymerization.

The acrylic resin (A) used in the present invention comprises a reactive functional group-containing monomer (a1), a (meth) acrylic acid alkyl ester monomer (a2) and other copolymerizable ethylenic monomers as required. It can be produced by appropriately selecting and using a copolymerization component containing a saturated monomer (a3). The polymerization can be performed by a conventionally known method such as solution radical polymerization, suspension polymerization, bulk polymerization, emulsion polymerization or the like.
For example, a polymerization component containing a reactive functional group-containing monomer (a1) and a polymerization initiator are mixed or dropped in an organic solvent and polymerized under predetermined polymerization conditions. Of these polymerization methods, solution radical polymerization and bulk polymerization are preferable, and solution radical polymerization is more preferable.

Examples of the organic solvent used in the polymerization reaction include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, esters such as ethyl acetate and butyl acetate, n-propyl alcohol, and isopropyl alcohol. Aliphatic alcohols such as acetone, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
Among these solvents, ethyl acetate, acetone, methyl ethyl ketone, butyl acetate, toluene, and methyl isobutyl ketone are preferred from the viewpoint of ease of polymerization reaction, chain transfer effect, ease of drying during adhesive coating, and safety. More preferably, they are ethyl acetate, acetone, and methyl ethyl ketone.

Examples of the polymerization initiator used in such radical polymerization include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, which are usual radical polymerization initiators, Azo initiators such as 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (methylpropionic acid), benzoyl peroxide, lauryl peroxide, di-t-butyl peroxide, cumene Examples thereof include organic peroxides such as hydroperoxide, which can be appropriately selected according to the monomer used. These solvents are used alone or in combination of two or more.

The lower limit of the weight average molecular weight of the acrylic resin (A) is preferably 600,000 or more, more preferably 800,000 or more, and still more preferably 1,000,000 or more. The upper limit of the weight average molecular weight of the acrylic resin (A) is preferably 2.5 million or less, more preferably 1.8 million or less, and still more preferably 1.6 million or less.
If the weight average molecular weight is too small, the durability tends to decrease, and if the weight average molecular weight is too large, a large amount of a diluent solvent is required during production, and the drying property tends to decrease.

The degree of dispersion (weight average molecular weight / number average molecular weight) of the acrylic resin (A) is preferably 30 or less, more preferably 15 or less, still more preferably 7 or less, and particularly preferably 5 or less.
If the degree of dispersion is too high, the cohesive force tends to decrease. The lower limit of the degree of dispersion is 1.

In addition, said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, and it is a column in high performance liquid chromatography (The Japan Waters company "Waters 2695 (main body)" and "Waters 2414 (detector)"). : Shodex GPC KF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plates / piece, filler material: styrene-divinylbenzene copolymer, filler Particle size: 10 μm) is used in series, and the sample concentration is about 1 mg / ml, the developing solvent is THF, and the flow rate is 1 ml / min. The number average molecular weight is also measured by the same method. be able to. The degree of dispersion is determined from the weight average molecular weight and the number average molecular weight.

The glass transition temperature (Tg) of the acrylic resin (A) is preferably −80 to 0 ° C., more preferably −60 to −15 ° C., and further preferably −60 to −20 ° C.
If the glass transition temperature is too high, the tack tends to decrease, and if it is too low, the heat resistance tends to decrease.

The glass transition temperature is calculated from the following Fox equation.
1 / Tg = w1 / Tg1 + w2 / Tg2 + ... Wk / Tgk
Where Tg is the glass transition temperature of the copolymer, Tg1, Tg2,... Tgk is the Tg of the homopolymer of each monomer component, w1, w2, ... Wk represents the weight fraction of each monomer component, and w1 + w2 +... Wk = 1.

The refractive index of the acrylic resin (A) is usually 1.440 to 1.600, preferably 1.440 to 1.550, particularly preferably 1.440 to 1.500. It is preferable to reduce the difference between the refractive index and the refractive index of the member to be laminated because light loss at the member interface is reduced.
The refractive index is a value obtained by measuring an acrylic resin with a NaD line using a refractive index measuring device ("Abbe refractometer 1T" manufactured by Atago Co., Ltd.).

The haze of the acrylic resin (A) is preferably 1.0% or less, more preferably 0.8% or less, and particularly preferably 0.5% or less.
If the haze is too high, the image quality of the display tends to deteriorate. In addition, as a minimum of this haze, it is 0.01% normally.

Thus, the acrylic resin (A) used in the present invention is obtained.

The acrylic resin (B) is an acrylic resin (B) obtained by polymerizing a polymerization component that does not contain a reactive functional group-containing monomer, and the polymerization component requires a non-reactive polar functional group-containing monomer (b1). (Meth) acrylic acid alkyl ester monomer (b2) or other copolymerizable ethylenically unsaturated monomer (b3) may be included as a copolymerization component.
The reactivity and non-reactivity in the acrylic resin (B) are the same as the reactivity in the acrylic resin (A), under general crosslinking reaction conditions for the crosslinking agent (C) described below (for example, no reaction) Reactivity and non-reactivity (which can be confirmed by the presence or absence of an increase in gel fraction) at 60 ° C. or less under a catalyst.

As the non-reactive polar functional group-containing monomer (b1), for example,
When the crosslinking agent is an isocyanate group-containing crosslinking agent, an acetoacetoxy group-containing monomer, a tertiary amino group (amino group not containing active hydrogen) -containing monomer, an amide group-containing monomer, an epoxy group-containing monomer, or an ether group-containing monomer Mentioned;
When the crosslinking agent is a carboxyl group-containing crosslinking agent, examples include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, and an ether group-containing monomer;
When the crosslinking agent is an acid anhydride structure-containing crosslinking agent, examples include a carboxyl group-containing monomer, a carboxylic anhydride-containing monomer, and an acetoacetoxy group-containing monomer;
When the crosslinking agent is a hydroxyl group-containing crosslinking agent, examples thereof include carboxyl group-containing monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, and ether group-containing monomers;
When the crosslinking agent is a glycidyl group-containing crosslinking agent, a tertiary amino group (amino group not containing active hydrogen) -containing monomer, amide group-containing monomer, ether group-containing monomer, isocyanate group-containing monomer, epoxy group-containing monomer, hydroxyl group -Containing monomers and acetoacetoxy group-containing monomers.

These non-reactive polar functional group-containing monomers (b1) may be used alone or in combination of two or more.

Among these, (meth) acrylate monomers of each monomer are preferable. Specifically, amide group-containing (meth) acrylate, tertiary amino group (amino group not containing active hydrogen) -containing (meth) acrylate, ether group Containing (meth) acrylates are preferable, and amide group-containing (meth) acrylates are particularly preferable in terms of excellent compatibility with the acrylic resin (A) and excellent durability.

Examples of the amide group-containing (meth) acrylate include methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, isopropoxymethyl (meth) acrylamide, and n-butoxymethyl (meth) acrylamide. , Alkoxyalkyl (meth) acrylamide monomers such as isobutoxymethyl (meth) acrylamide, (meth) acryloylmorpholine, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, (meth) acrylamide N-methylol (meth) acrylamide, etc. And (meth) acrylamide monomers.
Among these, dialkyl (meth) acrylamide is preferable from the viewpoint of stability during polymerization and stability during storage, and dimethylacrylamide is particularly preferable because of high molecular weight.

Examples of the tertiary amino group-containing (meth) acrylate include t-butylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like.

Examples of the ether group-containing (meth) acrylate include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2 -Butoxydiethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, octoxy Polyethylene glycol-polypropylene glycol-mono (meth) acrylate, Lauroxy polyethylene glycol mono (meth) acrylate And ether chain-containing (meth) acrylates such as stearoxy polyethylene glycol mono (meth) acrylate.

The content of the non-reactive polar functional group-containing monomer (b1) is preferably from 0.1 to 30% by weight, particularly preferably from 0.5 to 30% by weight, more preferably based on the whole polymerization component. Is 1 to 25% by weight, particularly preferably 3 to 25% by weight.
If the content of the non-reactive polar functional group-containing monomer (b1) is too large, the heat-and-moisture resistance tends to decrease and the stability during storage tends to decrease. If the content is too small, the acrylic resin (A) There is a tendency that the compatibility with is lowered.

Examples of the (meth) acrylic acid alkyl ester monomer (b2) include those similar to the (meth) acrylic acid alkyl ester monomer (a2) described above. For example, the carbon number of the alkyl group Are usually 1 to 20, preferably 1 to 18, particularly preferably 1 to 12, and more preferably 1 to 8. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n -Butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-propyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (Meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acryl Over DOO, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate. These may be used alone or in combination of two or more.

Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferable from the viewpoints of versatility and adhesive properties. It is preferable to do.

The content of the (meth) acrylic acid alkyl ester monomer (b2) is preferably 60 to 99.9% by weight, particularly preferably 70 to 99.5% by weight, more preferably 75%, based on the entire polymerization component. ~ 95% by weight.
If the content is too small, the compatibility with the reactive functional group-containing acrylic resin (A) tends to decrease, and the resin price tends to increase. There exists a tendency for compatibility with resin (A) to fall.

As the other copolymerizable ethylenically unsaturated monomer (b3), for example,
Aromatic ring-containing monomers such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, orthophenylphenoxyethyl (meth) acrylate;
Cyclohexyl (meth) acrylate, cyclohexyloxyalkyl (meth) acrylate, t-butylcyclohexyloxyethyl (meth) acrylate isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyl (meth) Alicyclic monomers such as acrylate and isobornyl (meth) acrylate;
Examples include acrylonitrile, methacrylonitrile, vinyl acetate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyl toluene, vinyl pyrrolidone, methyl vinyl ketone, and dimethylallyl vinyl ketone. These may be used alone or in combination of two or more.

Among these, an aromatic ring-containing monomer is preferable in terms of easy adjustment of the refractive index and birefringence, and particularly preferably benzyl (meth) acrylate, phenoxy (meth) ethyl acrylate, phenoxydiethylene glycol (meth) acrylate, refraction. An alicyclic-containing monomer is preferable in terms of easy adjustment of the rate and birefringence and excellent adhesion to a low-polar adherend (cycloolefin).

The content of the other copolymerizable ethylenically unsaturated monomer (b3) is preferably 0 to 35 with respect to the entire polymerization component when (b3) is an aromatic ring-containing monomer or alicyclic ring-containing monomer. % By weight, particularly preferably 0 to 25% by weight, more preferably 0 to 15% by weight. When there is too much this content, there exists a tendency for a glass transition temperature to become high and for a rework property to fall.

Further, when (b3) is other than an aromatic ring-containing monomer or an alicyclic ring-containing monomer, it is preferably 0 to 10% by weight, particularly preferably 0 to 5% by weight, based on the entire polymerization component. When there is too much this content, there exists a tendency for the long-term storage stability of acrylic resin (B) to fall, or the compatibility of acrylic resin (A) and acrylic resin (B) to fall.

The acrylic resin (B) used in the present invention comprises a non-reactive polar functional group-containing monomer (b1), and, if necessary, a (meth) acrylic acid alkyl ester monomer (b2) or other copolymerizable ethylene. It can be produced by appropriately selecting and using a copolymerization component containing a polymerizable unsaturated monomer (b3). The polymerization can be performed by a conventionally known method such as solution radical polymerization, suspension polymerization, bulk polymerization, emulsion polymerization or the like.
For example, a polymerization component containing a non-reactive polar functional group-containing monomer (b1) and a polymerization initiator are mixed or dropped in an organic solvent and polymerized under predetermined polymerization conditions. Of these polymerization methods, solution radical polymerization and bulk polymerization are preferred, and solution radical polymerization is more preferred.

Examples of the organic solvent used in the polymerization reaction include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, esters such as ethyl acetate and butyl acetate, n-propyl alcohol, and isopropyl alcohol. Aliphatic alcohols such as acetone, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
Among these solvents, ethyl acetate, acetone, methyl ethyl ketone, butyl acetate, toluene, and methyl isobutyl ketone are preferred from the viewpoint of ease of polymerization reaction, chain transfer effect, ease of drying during adhesive coating, and safety. More preferably, they are ethyl acetate, acetone, and methyl ethyl ketone.

Examples of the polymerization initiator used in such radical polymerization include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, which are usual radical polymerization initiators, Azo initiators such as 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (methylpropionic acid), benzoyl peroxide, lauryl peroxide, di-t-butyl peroxide, cumene Examples thereof include organic peroxides such as hydroperoxide, which can be appropriately selected according to the monomer used. These solvents are used alone or in combination of two or more.

The lower limit of the weight average molecular weight of the acrylic resin (B) is preferably 600,000 or more, more preferably 800,000 or more, and still more preferably 1,000,000 or more. The upper limit of the weight average molecular weight of the acrylic resin (B) is preferably 2.5 million or less, more preferably 1.8 million or less, and still more preferably 1.6 million or less.
If the weight average molecular weight is too small, the durability tends to decrease, and if the weight average molecular weight is too large, a large amount of a diluent solvent is required during production, and the drying property tends to decrease.

The degree of dispersion (weight average molecular weight / number average molecular weight) of the acrylic resin (B) is preferably 30 or less, more preferably 15 or less, still more preferably 7 or less, and particularly preferably 5 or less.
If the degree of dispersion is too high, the cohesive force tends to decrease. The lower limit of the degree of dispersion is 1.

The method for measuring the weight average molecular weight is the same as described above.

The glass transition temperature (Tg) of the acrylic resin (B) is preferably −80 to 0 ° C., more preferably −60 to −10 ° C., and further preferably −60 to −20 ° C.
If the glass transition temperature is too high, the tack tends to decrease, and if it is too low, the heat resistance tends to decrease.

The method for measuring the glass transition temperature is the same as described above.

The refractive index of the acrylic resin (B) is usually adjusted in the range of 1.440 to 1.600, preferably 1.440 to 1.550, particularly preferably 1.440 to 1.500. . It is preferable to reduce the difference between the refractive index and the refractive index of the member to be laminated because light loss at the member interface is reduced.
The method for measuring the refractive index is the same as described above.

The haze of the acrylic resin (B) is preferably 1.0% or less, more preferably 0.8 or less, and particularly preferably 0.5% or less.
If the haze is too high, the image quality of the display tends to deteriorate. The lower limit of haze is usually 0.01%.

Thus, the acrylic resin (B) used in the present invention is obtained.

The pressure-sensitive adhesive composition of the present invention contains the acrylic resin (A) and the acrylic resin (B) as essential components.

The content ratio of the acrylic resin (A) to the acrylic resin (B) ((A) :( B) (weight ratio) is (A) :( B) = 100: 50 to 100: 500. More preferably, (A) :( B) = 100: 100 to 100: 400, and more preferably 100: 100 to 100: 350.
If the content ratio of the acrylic resin (B) relative to the acrylic resin (A) is too large, the degree of crosslinking tends to decrease and the cohesive force tends to decrease, and if it is too small, the degree of crosslinking tends to increase and stress relaxation properties tend to decrease.

The pressure-sensitive adhesive composition of the present invention preferably contains a crosslinking agent (C), and is crosslinked with the crosslinking agent (C) to become a pressure-sensitive adhesive.

Examples of the crosslinking agent (C) include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, aldehyde crosslinking agents, amine crosslinking agents, and metal chelate crosslinking agents. Among these, an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent are preferable because they are excellent in durability and light leakage resistance.

Examples of the isocyanate crosslinking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, hexamethylene. Diisocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and polyisocyanate compounds thereof And adducts of a polyol compound such as trimethylolpropane, and burettes and isocyanurates of these polyisocyanate compounds. Among them, an adduct body of 2,4-tolylene diisocyanate with trimethylolpropane is particularly preferable in view of long pot life and excellent compatibility with the resin.

Examples of the epoxy-based crosslinking agent include bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, and 1,6-hexanediol diglycidyl ether. , Trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether and the like. Of these, 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N′N′-tetraglycidyl-m-xylylenediamine is particularly preferred because of its high reactivity.

Examples of the aziridine-based crosslinking agent include tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4,4. Examples include '-bis (1-aziridinecarboxamide), N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), and the like.

Examples of the melamine-based crosslinking agent include hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexaptoxymethyl melamine, hexapentyloxymethyl melamine, hexahexyloxymethyl melamine, and melamine resin. .

Examples of the aldehyde-based crosslinking agent include glyoxal, malondialdehyde, succindialdehyde, maleindialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, benzaldehyde and the like.

Examples of the amine-based crosslinking agent include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resin, and polyamide.

Examples of the metal chelate-based crosslinking agent include acetylacetone and acetoacetyl ester coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. Can be mentioned.

These cross-linking agents (C) may be used alone or in combination of two or more. It is preferable from the viewpoint of durability to use an isocyanate crosslinking agent and an epoxy crosslinking agent in combination.

The content of the cross-linking agent is preferably 0.1 to 15 parts by weight, more preferably 0.3 to 10 parts by weight, and still more preferably 0.00 with respect to 100 parts by weight of the acrylic resin (A). 5 to 10 parts by weight, particularly preferably 1.0 to 7.5 parts by weight.
When the amount of the crosslinking agent is too small, the durability tends to be lowered. When the amount is too large, the stress relaxation property is lowered or long-term aging is required.

In the pressure-sensitive adhesive composition of the present invention, it is preferable to further contain a silane coupling agent (D) from the viewpoint of improving the adhesion to the optical member, and it is preferable to contain an antistatic agent (E). It is preferable in that the antistatic property at the time is excellent.

Examples of the silane coupling agent (D) include an epoxy group-containing silane coupling agent, a (meth) acryloyl group-containing silane coupling agent, a mercapto group-containing silane coupling agent, a hydroxyl group-containing silane coupling agent, and a carboxyl group-containing. Examples thereof include a silane coupling agent, an amino group-containing silane coupling agent, an amide group-containing silane coupling agent, and an isocyanate group-containing silane coupling agent. These may be used alone or in combination of two or more. Among these, an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent are preferably used, and the combined use of an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent also improves wet heat durability. It is preferable in that the adhesive strength does not increase too much.
In addition, oligomeric silane compounds partially hydrolyzed and polycondensed are also preferred in that they are excellent in durability and reworkability.

Specific examples of the epoxy group-containing silane coupling agent include, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycol. Sidoxypropylmethyldimethoxysilane, methyltri (glycidyl) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.

Specific examples of the mercapto group-containing silane coupling agent include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyldimethoxymethylsilane, SH group-containing silicone alkoxy oligomer (mercapto group-modified). Ethyl / methyl silicate low condensate).

The content of the silane coupling agent (D) is usually 0.001 to 10 parts by weight, preferably 0 with respect to 100 parts by weight in total of the acrylic resin (A) and the acrylic resin (B). 0.01 to 1 part by weight, particularly preferably 0.02 to 0.5 part by weight.
If the content of the silane coupling agent (D) is too small, there is a tendency that the effect of addition cannot be obtained. If the content is too large, the adhesiveness of the adhesive is excessively increased and the reworkability is lowered or the adhesive surface is reduced. Bleeding out tends to reduce durability.

Examples of the antistatic agent (E) include cationic antistatic agents of quaternary ammonium salts such as imidazolium salts and tetraalkylammonium sulfonates, aliphatic sulfonates, higher alcohol sulfates, and higher alcohols. Anionic antistatic agent such as alkylene oxide adduct sulfate ester salt, higher alcohol phosphate ester salt, higher alcohol alcohol alkylene oxide adduct phosphate ester salt, potassium bis (fluorosulfonyl) imide, lithium bis (trifluorosulfonyl) imide And alkali metal salts such as lithium chloride, alkaline earth metal salts, higher alcohol alkylene oxide adducts, polyalkylene glycol fatty acid esters and the like.

The content of the antistatic agent (E) is usually 0.1 to 10 parts by weight with respect to a total of 100 parts by weight of the acrylic resin (A) and the acrylic resin (B), preferably 0.8. 5 to 5 parts by weight, particularly preferably 0.5 to 3 parts by weight.
If the content of the antistatic agent (E) is too small, there is a tendency that the effect of addition cannot be obtained. If the content is too large, bleeding tends to occur on the surface of the pressure-sensitive adhesive and durability tends to decrease.

Furthermore, in the pressure-sensitive adhesive composition of the present invention, other acrylic pressure-sensitive adhesives, other pressure-sensitive adhesives, urethane resins, rosins, rosin esters, hydrogenated rosin esters, phenol resins, as long as the effects of the present invention are not impaired. Various additives such as tackifiers such as aliphatic petroleum resins, alicyclic petroleum resins, styrene resins, colorants, fillers, antioxidants, ultraviolet absorbers, functional dyes, and ultraviolet or radiation irradiation A compound that causes coloration or discoloration can be blended. In addition to the above additives, a small amount of impurities and the like contained in the raw materials for producing the constituent components of the pressure-sensitive adhesive composition may be contained. What is necessary is just to set these compounding quantities suitably so that the desired physical property may be obtained.

The pressure-sensitive adhesive composition of the present invention can be made into a pressure-sensitive adhesive by crosslinking (curing), and further, by laminating and forming a pressure-sensitive adhesive layer comprising such a pressure-sensitive adhesive on an optical member (optical laminate), An optical member with an adhesive layer can be obtained.

In the optical member with the pressure-sensitive adhesive layer, it is preferable to further provide a release sheet on the surface opposite to the optical member surface of the pressure-sensitive adhesive layer.

As the method for producing the optical member with the pressure-sensitive adhesive layer, when the pressure-sensitive adhesive composition is cured by at least one of active energy ray irradiation and heating, [1] the pressure-sensitive adhesive composition is applied onto the optical member. After drying, a release sheet is pasted, and a treatment is carried out by at least one of irradiation with active energy rays and aging at room temperature or in a heated state. [2] An adhesive composition is applied on the release sheet After drying, the optical member is bonded, and a method of performing treatment by active energy ray irradiation and at least one of aging at normal temperature or in a heated state, [3] Applying an adhesive composition on the optical member and drying Further, a method of pasting a release sheet after performing treatment with at least one of irradiation with active energy rays and aging at room temperature or in a heated state, [4] release sheet Applying an adhesive composition to dry and, after further conducted at least one by treatment aging the active energy ray irradiation and room temperature or under heating conditions, and a method of bonding an optical member.
Among these, aging at room temperature by the method [2] is preferable in that it does not damage the substrate and is excellent in adhesion to the substrate.

Such aging treatment is performed to balance the physical properties of the adhesive as the reaction time of the chemical cross-linking of the adhesive. As the aging conditions, the temperature is usually from room temperature to 70 ° C., and the time is usually from 1 day to 30 days. Specifically, for example, the treatment may be performed under conditions such as 23 ° C. for 1 day to 20 days, 23 ° C. for 3 days to 10 days, 40 ° C. for 1 day to 7 days, and the like.

In applying the pressure-sensitive adhesive composition, it is preferable to dilute the pressure-sensitive adhesive composition in a solvent, and the diluted concentration is preferably 5 to 60% by weight, particularly preferably 10%, as the heating residue concentration. ~ 30% by weight. The solvent is not particularly limited as long as it dissolves the pressure-sensitive adhesive composition. For example, ester solvents such as methyl acetate, ethyl acetate, methyl acetoacetate, and ethyl acetoacetate, acetone, methyl ethyl ketone, A ketone solvent such as methyl isobutyl ketone, an aromatic solvent such as toluene and xylene, and an alcohol solvent such as methanol, ethanol and propyl alcohol can be used. Among these, ester solvents, particularly ethyl acetate, ketone solvents, particularly methyl ethyl ketone, are preferably used from the viewpoints of solubility, drying properties, cost, and the like.

In addition, the application of the pressure-sensitive adhesive composition is performed by a conventional method such as roll coating, die coating, gravure coating, comma coating, or screen printing.

The gel fraction of the pressure-sensitive adhesive layer produced by the above method is preferably 30 to 95%, particularly preferably 40 to 85%, more preferably 45, from the viewpoint of durability performance and light leakage prevention performance. ~ 80%. If the gel fraction is too low, durability tends to be insufficient due to insufficient cohesive force. On the other hand, if the gel fraction is too high, tackiness is insufficient due to an increase in cohesive force, and there is a tendency that a crack or peeling occurs easily.
Moreover, it is preferable that the gel fraction measured by the said measurement is 10% or more higher than the ratio for which the weight which added the acrylic resin (A) and crosslinking agent (C) in an adhesive accounts to the weight of the whole adhesive. More preferably, it is 15% or more. If it is too low, the durability tends to decrease.

The pressure-sensitive adhesive layer produced by the above method preferably has a good tack feeling when touched with a finger, because it has good wettability when actually attached to an adherend, and therefore tends to improve workability. .

In adjusting the gel fraction of the pressure-sensitive adhesive for optical members to the above range, for example, adjusting the amount and type of the crosslinking agent; the blending ratio of the acrylic resin (A) and the acrylic resin (B) It is achieved by adjusting; adjusting the functional group amount and type of the acrylic resin (A); adjusting the molecular weight of the acrylic resin (A) and / or the acrylic resin (B);

The gel fraction is a measure of the degree of crosslinking (curing degree), and is calculated, for example, by the following method. That is, about 0.1 g of the pressure-sensitive adhesive layer is scraped off from a pressure-sensitive adhesive sheet (not provided with a separator) in which a pressure-sensitive adhesive layer is formed on a polarizing plate as a base material, and the pressure-sensitive adhesive layer is formed with a 200 mesh SUS metal mesh. Wrapped in ethyl acetate at 23 ° C. for 24 hours, the weight percentage of the insoluble adhesive component remaining in the wire mesh is taken as the gel fraction.

Further, the thickness of the pressure-sensitive adhesive layer in the obtained optical member with the pressure-sensitive adhesive layer is preferably 5 to 300 μm, particularly preferably 10 to 50 μm, and further preferably 10 to 30 μm. If the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive physical properties tend to be difficult to stabilize, and if it is too thick, the rework property tends to decrease or the thickness of the entire optical member tends to increase too much.

The optical member with the pressure-sensitive adhesive layer of the present invention is directly or directly having a release sheet, and after peeling off the release sheet, the surface of the pressure-sensitive adhesive layer is bonded to a glass substrate and used for, for example, a liquid crystal display board.

The initial adhesive strength of the pressure-sensitive adhesive layer of the present invention is appropriately determined according to the material of the adherend. For example, when adhering to a glass substrate, it preferably has an adhesive strength of 0.2 N / 25 mm to 15 N / 25 mm, more preferably 0.5 N / 25 mm to 10 N / 25 mm, and still more preferably 1 N / 25 mm to 10 N / 25 mm.

The initial adhesive strength is calculated as follows. About the polarizing plate with an adhesive layer, it cuts to width 25mm width, peels off a release film, presses the adhesive layer side to a non-alkali glass board (Corning company make, "Eagle XG"), A glass plate is bonded. Thereafter, autoclaving (50 ° C., 0.5 MPa, 20 minutes) is performed, and after leaving at 23 ° C. and 50% RH for 24 hours, a 180 ° C. peeling test is performed.

The optical member in the present invention is not particularly limited, and an optical film suitably used for an image display device such as a liquid crystal display device, an organic EL display device, or a PDP, such as a polarizing plate, a retardation plate, or an elliptical polarizing plate. , Optical compensation films, brightness enhancement films, and those in which these are laminated. Among them, a polarizing plate is particularly effective in the present invention.

The polarizing plate used in the present invention is usually one obtained by laminating a triacetyl cellulose (TAC) film as a protective film on both sides of a polarizing film, and the polarizing film has an average degree of polymerization of 1,500 to 10, A uniaxially stretched film dyed with an aqueous solution of iodine-potassium iodide or a dichroic dye using a film made of a polyvinyl alcohol resin having a saponification degree of 85 to 100 mol% as an original film (usually 2 to 10 Times, preferably a stretching ratio of about 3 to 7 times).

The polyvinyl alcohol resin is usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but a small amount of unsaturated carboxylic acid (including salt, ester, amide, nitrile, etc.), olefins, vinyl ether And a component copolymerizable with vinyl acetate, such as an unsaturated sulfonate. Moreover, what is called polyvinyl acetal resin and polyvinyl alcohol derivatives, such as polybutyral resin and polyvinyl formal resin, which are obtained by reacting polyvinyl alcohol with an aldehyde in the presence of an acid can be mentioned.

Examples of the protective film for the polarizing plate include an acrylic film, a polyethylene film, a polypropylene film, and a cycloolefin film in addition to a commonly used triacetyl cellulose film.
Moreover, the single-sided protective film polarizing plate which eliminated the protective film on the side bonded to an optical member for film thickness reduction is also mentioned.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, “parts” and “%” mean weight basis.

First, various acrylic resins were prepared as follows. In addition, regarding the measurement of the weight average molecular weight, dispersion degree, glass transition temperature, and refractive index of acrylic resin (A) and acrylic resin (B), it measured according to the above-mentioned method.
In addition, regarding the measurement of a viscosity, it measured according to the 4.5.3 rotational viscometer method of JISK5400 (1990).

[Preparation of acrylic resin (A)]

<Manufacture of acrylic resin (A-1)>
In a 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 86.5 parts of butyl acrylate (BA) (a2), benzyl acrylate (BzA) (a3) 10 Parts, 2-hydroxyethyl acrylate (HEA) (a1) 0.5 part, acrylic acid (AAc) (a1) 3 parts, ethyl acetate 47.2 parts, acetone 42 parts, azobisisobutyronitrile as a polymerization initiator (AIBN) 0.013 part was added, and AIBN and ethyl acetate were added appropriately, followed by reaction at reflux temperature for 3.25 hours, and then diluted with ethyl acetate to obtain an acrylic resin (A-1) solution (weight average molecular weight of 150 And a dispersity of 3.1, a glass transition temperature of −48 ° C., a solid content concentration of 19.5%, a viscosity of 4580 mPa · s (25 ° C.), and a refractive index of 1.477).

<Manufacture of acrylic resin (A-2)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 84.5 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl 0.5 parts of acrylate (a1), 5 parts of acrylic acid (a1), 47.2 parts of ethyl acetate, 42 parts of acetone, and 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator are charged appropriately. And ethyl acetate were added and reacted at reflux temperature for 3.25 hours, then diluted with ethyl acetate to obtain an acrylic resin (A-2) solution (weight average molecular weight 1,500,000, dispersity 3.3, glass transition temperature− 46 ° C., solid content concentration 19.9%, viscosity 5640 mPa · s (25 ° C.), refractive index 1.478).

<Manufacture of acrylic resin (A-3)>
In a 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 82 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate ( a1) 0.5 parts, 7.5 parts of acrylic acid (a1), 47.2 parts of ethyl acetate, 42 parts of acetone, and 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator were added appropriately. And ethyl acetate were added and reacted at reflux temperature for 3.25 hours, then diluted with ethyl acetate to obtain an acrylic resin (A-3) solution (weight average molecular weight 1.4 million, dispersity 3.6, glass transition temperature− 43 ° C., solid content concentration 19.9%, viscosity 6380 mPa · s (25 ° C.), refractive index 1.479).

<Manufacture of acrylic resin (A-4)>
In a four-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 84.4 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl 0.6 parts of acrylate (a1), 5 parts of acrylic acid (a1), 47.2 parts of ethyl acetate, 42 parts of acetone and 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator were added appropriately. And ethyl acetate were added and reacted at reflux temperature for 3.25 hours, and then diluted with ethyl acetate to prepare an acrylic resin (A-4) solution (weight average molecular weight 1.5 million, dispersity 3.8, glass transition temperature− 46 ° C., solid content concentration 19.9%, viscosity 6380 mPa · s (25 ° C.), refractive index 1.478).

<Manufacture of acrylic resin (A-5)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 84.5 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl 5 parts of acrylate (a1), 0.5 part of acrylic acid (a1), 47.2 parts of ethyl acetate, 42 parts of acetone, and 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator are added appropriately. And ethyl acetate were added and reacted at reflux temperature for 3.25 hours, and then diluted with ethyl acetate to obtain an acrylic resin (A-5) solution (weight average molecular weight 1.4 million, dispersity 3.0, glass transition temperature− 49 ° C., solid concentration 20.6%, viscosity 7500 mPa · s (25 ° C.), refractive index 1.477).

<Manufacture of acrylic resin (A-6)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 62.4 parts of butyl acrylate (a2), 30 parts of benzyl acrylate (a3), 2-hydroxyethyl Acrylate (a1) 0.6 part, acrylic acid (a1) 7 part, ethyl acetate 48.3 parts, acetone 37.5 parts, azobisisobutyronitrile (AIBN) 0.013 part as a polymerization initiator, After adding AIBN and ethyl acetate as appropriate and reacting at reflux temperature for 3.25 hours, diluting with ethyl acetate and acryl resin (A-6) solution (weight average molecular weight 1.4 million, dispersity 4.2, glass transition A temperature of −33 ° C., a solid content concentration of 22.6%, a viscosity of 8700 mPa · s (25 ° C.), and a refractive index of 1.498 were obtained.

<Manufacture of acrylic resin (A'-1)>
A four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer was charged with 88 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate ( a1) 0.5 parts, 1.5 parts of acrylic acid (a1), 47.2 parts of ethyl acetate, 42 parts of acetone, 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator are charged appropriately and AIBN And ethyl acetate were added and reacted at reflux temperature for 3.25 hours, and then diluted with ethyl acetate to obtain an acrylic resin (A′-1) solution (weight average molecular weight 1.4 million, dispersity, 3.5, glass transition The temperature was -49 ° C, the solid content concentration was 19.8%, the viscosity was 4780 mPa · s (25 ° C), and the refractive index was 1.476).

[Preparation of acrylic resin (B)]

<Acrylic resin (B-1)>
In a 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 93 parts of butyl acrylate (BA) (b2), 2 parts of methyl methacrylate (MMA) (b2), Charge 5 parts of dimethylacrylamide (DMAA) (b1), 43 parts of ethyl acetate, 42 parts of acetone, 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator, and reflux with appropriate addition of AIBN and ethyl acetate. After reacting at temperature for 3.25 hours, diluted with ethyl acetate to obtain an acrylic resin (B-1) solution (weight average molecular weight 1.1 million, dispersity 4.6, glass transition temperature −49 ° C., solid content concentration 22. 1%, a viscosity of 3800 mPa · s (25 ° C.), and a refractive index of 1.469).

<Acrylic resin (B-2)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 90.5 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), dimethylacrylamide (b1 ) 7.5 parts, 43 parts of ethyl acetate, 42 parts of acetone, 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 3.25 at reflux temperature while appropriately adding AIBN and ethyl acetate. After the reaction for a while, diluted with ethyl acetate to obtain an acrylic resin (B-2) solution (weight average molecular weight 1.1 million, dispersity 3.4, glass transition temperature −47 ° C., solid content concentration 22.5%, viscosity 4900 mPa · s (25 ° C.), refractive index 1.470) was obtained.

<Acrylic resin (B-3)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 88 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), and dimethylacrylamide (b1) 10 Part, ethyl acetate 43 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 part as a polymerization initiator, and after reacting at reflux temperature for 3.25 hours while adding AIBN and ethyl acetate as appropriate, Diluted with ethyl acetate to obtain an acrylic resin (B-3) solution (weight average molecular weight 1.3 million, dispersity 4.0, glass transition temperature -44 ° C., solid content concentration 22.4%, viscosity 4800 mPa · s (25 ° C) and a refractive index of 1.472).

<Acrylic resin (B-4)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 83 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), dimethylacrylamide (b1) 15 Part, ethyl acetate 43 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 part as a polymerization initiator, and after reacting at reflux temperature for 3.25 hours while adding AIBN and ethyl acetate as appropriate, Diluted with ethyl acetate to obtain an acrylic resin (B-4) solution (weight average molecular weight 1.3 million, dispersity 4.3, glass transition temperature -38 ° C., solid content concentration 23.4%, viscosity 7900 mPa · s (25 ° C) and a refractive index of 1.475).

<Acrylic resin (B-5)>
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 78 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), dimethylacrylamide (b1) 20 Part, ethyl acetate 43 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 part as a polymerization initiator, and after reacting at reflux temperature for 3.25 hours while adding AIBN and ethyl acetate as appropriate, Diluted with ethyl acetate to obtain an acrylic resin (B-5) solution (weight average molecular weight 1.4 million, dispersity 3.6, glass transition temperature -33 ° C., solid content concentration 22.2%, viscosity 4500 mPa · s (25 ° C) and a refractive index of 1.478).

<Acrylic resin (B-6)>
In a 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 93 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), dimethylacrylamide (b1) 5 Parts, ethyl acetate 22 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 part as a polymerization initiator, and after reacting at reflux temperature for 3.25 hours while appropriately adding AIBN and ethyl acetate, Diluted with ethyl acetate to obtain an acrylic resin (B-6) solution (weight average molecular weight 1.3 million, dispersity 2.9, glass transition temperature -49 ° C., solid content concentration 22.7%, viscosity 8200 mPa · s (25 ° C) and a refractive index of 1.469).

<Acrylic resin (B'-1)>
In a four-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 98 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 43 parts of ethyl acetate, acetone 42 parts, 0.013 part of azobisisobutyronitrile (AIBN) as a polymerization initiator was added, reacted for 3.25 hours at reflux temperature while appropriately adding AIBN and ethyl acetate, diluted with ethyl acetate, and then acrylic. Resin (B′-1) solution (weight average molecular weight 1 million, dispersity 2.9, glass transition temperature −54 ° C., solid content concentration 22.0%, viscosity 4300 mPa · s (25 ° C.), refractive index 1. 466).

[Examples 1 to 16, Comparative Examples 1 to 9]
<Compatibility (transparency)>
In the combination shown in Table 3, the acrylic resin (A) and the acrylic resin (B) are blended so that the weight ratio (solid content ratio) is 1: 1, and the film thickness after drying is 25 μm. The film was coated on lightly peeled PET (Toray Industries, Inc., “Toray Mirror SP 01”: thickness 38 μm). After drying at 100 ° C. for 3 minutes, it is bonded to an alkali-free glass (Corning, “Eagle XG”: thickness 1.1 mm), the separator is removed, and a haze meter “HAZE MATER NDH2000” (Nippon Denshoku Industries Co., Ltd.) The compatibility (transparency) was evaluated by measuring haze (%). This machine conforms to JIS K7361-1. The evaluation criteria are as follows. The results are shown in Table 3.
(Evaluation)
○ ・ ・ ・ Haze is less than 1% × ・ ・ ・ Haze is 1% or more

[Crosslinking agent (C)]
The following were prepared as the crosslinking agent (C).
(C-1): 55% ethyl acetate solution of tolylene diisocyanate adduct of trimethylolpropane (“Coronate L-55E” manufactured by Nippon Polyurethane Co., Ltd.)
(C-2) 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane (“Tetrad-C” manufactured by Mitsubishi Gas Chemical Company)

[Silane coupling agent (D)]
The following were prepared as the silane compound (D).
(D-1): Oligomer type silane compound (“X41-1805” manufactured by Shin-Etsu Chemical Co., Ltd.)
(D-2): 3-glycidoxypropyltrimethoxysilane (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.)

[Antistatic agent (E)]
The following were prepared as the antistatic agent (E).
(E-1): Lithium bistrifluoromethanesulfonylimide (tetraethylene glycol dimethyl ether dispersion) (“Sanconol TGR” manufactured by Sanko Chemical Co., Ltd.)
(E-2): Tri-n-butylmethylammonium bistrifluoromethanesulfonimide (“FC-4400” manufactured by 3M)

[Examples 17 to 30, Comparative Examples 10 to 15]
A pressure-sensitive adhesive composition to be a pressure-sensitive adhesive forming material was prepared by blending each of the blended components prepared and prepared as described above in the ratio shown in Table 4 below, and this was diluted with ethyl acetate (viscosity [ 500 to 10000 mPa · s (25 ° C.)]), an adhesive composition solution was prepared.

Next, the pressure-sensitive adhesive composition solutions of Examples 17 to 30 and Comparative Examples 10 to 15 were applied to a polyester release sheet so that the thickness after drying was 25 μm, and dried at 100 ° C. for 3 minutes. The formed pressure-sensitive adhesive composition layer was transferred to a polarizing plate (protective film: TAC film manufactured by Fuji Film Co., Ltd.) and aged for 7 days at 23 ° C. and 65% RH to obtain a polarizing plate with a pressure-sensitive adhesive layer. It was.
In addition, the said polarizing plate was cut and used so that it might become 0 degree | times with respect to an extending | stretching axis | shaft.

Using the polarizing plate with the pressure-sensitive adhesive layer thus obtained, gel fraction, durability (moisture-heat resistance test, heat resistance test, heat cycle test), light leakage resistance, adhesive strength / rework property, holding power, charging Prevention performance and transparency were measured and evaluated according to the following methods. These results are also shown in Table 4 below.

[Gel fraction]
The release sheet of the obtained polarizing plate with the pressure-sensitive adhesive layer was peeled off, 0.1 g of the pressure-sensitive adhesive layer was scraped off, the pressure-sensitive adhesive layer was wrapped in a 200-mesh SUS wire net, and immersed in ethyl acetate at 23 ° C. for 24 hours. Then, the weight percentage of the insoluble adhesive component remaining in the wire mesh was determined.

[Durability, light leakage resistance]
The release sheet of the obtained polarizing plate with the pressure-sensitive adhesive layer was peeled off, and the pressure-sensitive adhesive layer side was pressed against a non-alkali glass plate (Corning Corp., Eagle XG) to bond the polarizing plate and the glass plate. Thereafter, autoclaving (50 ° C., 0.5 MPa, 20 minutes) was performed, and then foaming and peeling were evaluated in the following durability tests (wet heat resistance test, heat resistance test, heat cycle test).
Furthermore, in the heat resistance test, in addition to the evaluation of foaming and the like, a sample for light leakage observation in which the same sample is bonded to both the front and back surfaces so that the polarizing plate is crossed Nicol (stretching axis is 0-90 °). The following light leakage resistance was also evaluated. In addition, the used test piece size was punched into 20 cm × 15 cm. However, the light leakage test of Example 30 was used by punching to 31 cm × 17.4 cm.

〔durability〕
(1) Moisture and heat resistance test It evaluated as follows in the endurance test of 60 degreeC, 90% RH, and 168 hours.
(2) Heat resistance test In the durability test at 80 ° C for 168 hours, the evaluation was as follows.
(3) Heat cycle test The operation of standing at -30 ° C for 30 minutes and then leaving at 80 ° C for 30 minutes was defined as one cycle, and evaluated as follows in an endurance test of 168 cycles (168 hours).
(Evaluation criteria)
Each of the above (1) to (3) was evaluated for the presence of defects (foaming, streaks, floating, peeling).
◎ ・ ・ ・ No defects ○ ・ ・ ・ Defects within 0.5 mm from the end of the polarizing plate × ・ ・ ・ Defects within 0.5 mm from the end of the polarizing plate

(Light leakage resistance)
In an endurance test at 80 ° C. for 150 hours, light leakage resistance was measured and evaluated as follows. In addition, about Example 30, it measured and evaluated in the 50 degreeC, 90% RH, 150-hour durability test.
(measuring device)
・ "Eye Scale" (made by I System Co., Ltd.)
(Measurement condition)
・ Camera lens aperture No. 16
・ Camera GAIN10
・ Shutter speed 1/1000
・ Luminance 9000
Place the above sample for light leakage observation on the backlight set to
・ Camera lens aperture No. 4
・ Camera GAIN6
・ Shutter speed 1/30
The film was photographed under the above conditions, and the light leakage was observed visually with respect to the captured image.
The evaluation criteria are as follows.
(Evaluation criteria)
A: No light leakage O: Slight light leakage X: Clear light leakage In Comparative Examples 11 to 15, light leakage could not be evaluated due to peeling of the polarizing plate.

[Adhesion / Rework]
The obtained polarizing plate with the pressure-sensitive adhesive layer was cut to a width of 25 mm, and then bonded to non-alkali glass (Corning Eagle XG), autoclaved (50 ° C., 0.5 MPa, 20 minutes), 23 ° C., After leaving still in a 50% RH atmosphere for 24 hours, a 180 ° peel test was performed to measure the adhesive strength, and the reworkability was evaluated as follows.
(Evaluation criteria)
◎ ・ ・ ・ 10N or less ○ ・ ・ ・ More than 10N and less than 15N × ・ ・ ・ 15N or more

[Retention force]
The polarizing plate with the pressure-sensitive adhesive layer is cut to 25 mm × 25 mm, the release sheet is peeled off, the pressure-sensitive adhesive layer side is attached to a polished SUS plate, and a load of 1 kg is applied at 80 ° C. Then, the deviation was evaluated according to the measuring method of the holding power of JIS Z 0237. The evaluation criteria are as follows.
(Evaluation criteria)
◎ ・ ・ ・ No shift after 1440 minutes (NC)
○: Deviation of less than 10 mm after 1440 minutes have elapsed × ... Deviation of 10 mm or more after 1440 minutes have elapsed

(Antistatic property)
The polarizing plate with the pressure-sensitive adhesive layer was allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH, and then the separator of the pressure-sensitive adhesive layer was removed, and a surface resistivity measuring device (manufactured by Mitsubishi Chemical Analytech Co., Ltd., “Hiresta- UP MCP-HT450 ") was used to measure the surface resistivity of the pressure-sensitive adhesive layer. The evaluation criteria are as follows.
(Evaluation criteria)
◎ ··· 1.0E + 11Ω / cm less than ^{2 ○ ··· 1.0E + 11Ω / cm} 2 or more, 1.0E + 12Ω / cm ² less than × ··· 1.0E + 12Ω / cm ² or more

〔transparency〕
After the pressure-sensitive adhesive composition solutions of Examples 17 to 30 and Comparative Examples 10 to 15 were applied to a polyester light release release sheet so that the thickness after drying was 25 μm, and dried at 100 ° C. for 3 minutes, A polyester-based heavy release release sheet was bonded to the formed pressure-sensitive adhesive composition layer, and aged for 7 days under conditions of 23 ° C. and 65% RH to obtain a pressure-sensitive adhesive layer-attached sheet. Remove the light release release sheet of the obtained sheet, paste it on alkali-free glass (Eagle XG manufactured by Corning), remove the heavy release sheet, and use a haze meter “HAZE MATER NDH2000” (manufactured by Nippon Denshoku Industries Co., Ltd.) Transparency was evaluated by measuring haze (%).
This machine conforms to JIS K7361-1. The evaluation criteria are as follows.
(Evaluation)
○ ・ ・ ・ Haze is less than 1% × ・ ・ ・ Haze is 1% or more

From the evaluation results of Table 4 above, the pressure-sensitive adhesives having the compositions of Examples 17 to 30 are excellent in compatibility with acrylic resins, and thus have high transparency, and are excellent in laminating a polarizing plate and a glass substrate. It can be seen that it exhibits durability (particularly heat cycle resistance), light leakage resistance, reworkability, and antistatic properties.

On the other hand, from Table 3, Comparative Examples 1 to 4 in which an acrylic resin (B′-1) containing no non-reactive polar functional group-containing monomer (b1) was blended with the acrylic resin (A). Then, it turns out that the compatibility of acrylic resin is inferior.

From Tables 3 and 4, Comparative Examples 5 to 8 in which the acrylic resin (A′-1) having a low content of the reactive functional group-containing monomer (a1) as a polymerization component and the acrylic resin (B) were blended were used. 10 and 11 show that the compatibility between the acrylic resins is excellent, but the durability is poor.

Furthermore, from Tables 3 and 4, the acrylic resin (A′-1) having a low content of the reactive functional group-containing monomer (a1) as a polymerization component and the non-reactive polar functional group-containing monomer (b1) as a polymerization component Comparative Examples 9 and 12 to 15 in which the acrylic resin (B′-1) not containing water is blended are excellent in compatibility between acrylic resins, but inferior in durability and light leakage resistance. .

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on July 18, 2014 (Japanese Patent Application No. 2014-147865), the contents of which are incorporated herein by reference.

The pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive exhibiting excellent durability performance (particularly heat cycle performance) when laminating a polarizing plate and a glass substrate, and further, light leakage resistance, rework property, antistatic property, Since an adhesive having excellent transparency (compatibility) can be formed, an optical member with an adhesive layer obtained by using as an adhesive for optical members, particularly a polarizing plate with an adhesive layer, and an image It is very useful as an adhesive for obtaining a display device.

Claims (11)

1. An acrylic resin (A) obtained by polymerizing a polymerization component containing a reactive functional group-containing monomer (a1), and an acrylic resin (B) obtained by polymerizing a polymerization component not containing a reactive functional group-containing monomer An adhesive composition comprising:
   The polymerization component of the acrylic resin (A) contains 2.5 to 30% by weight of the reactive functional group-containing monomer (a1), and the polymerization component of the acrylic resin (B) is a non-reactive polar functional group. A pressure-sensitive adhesive composition comprising the containing monomer (b1).
2. The pressure-sensitive adhesive composition according to claim 1, wherein the content ratio of the non-reactive polar functional group-containing monomer (b1) in the polymerization component of the acrylic resin (B) is 0.1 to 30% by weight.
3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the reactive functional group-containing monomer (a1) is at least one selected from the group consisting of a hydroxyl group-containing monomer and a carboxyl group-containing monomer.
4. The non-reactive polar functional group-containing monomer (b1) is at least one selected from the group consisting of an amide group-containing monomer, a tertiary amino group-containing monomer, and an ether group-containing monomer. The pressure-sensitive adhesive composition according to any one of the above.
5. The pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the acrylic resin (A) has a weight average molecular weight of 1,000,000 or more.
6. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein the acrylic resin (B) has a weight average molecular weight of 1,000,000 or more.
7. The content ratio [(A) :( B)] (weight ratio) of the acrylic resin (A) and the acrylic resin (B) is (A) :( B) = 100: 50 to 100: 500. The pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein
8. The pressure-sensitive adhesive composition according to any one of claims 1 to 7, further comprising a crosslinking agent (C).
9. The pressure-sensitive adhesive composition according to claim 8, wherein the crosslinking agent (C) is at least one selected from the group consisting of an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent.
10. 10. A pressure-sensitive adhesive, wherein the pressure-sensitive adhesive composition according to claim 1 is crosslinked with a crosslinking agent (C).
11. A pressure-sensitive adhesive for polarizing plates comprising the pressure-sensitive adhesive according to claim 10.