KR102301157B1 - Adhesive composition and adhesive using same, and adhesive for polarizing plate - Google Patents

Abstract

The pressure-sensitive adhesive composition of the present invention contains an acrylic resin (A) formed by polymerizing a polymerization component containing a reactive functional group-containing monomer (a1) and an acrylic resin (B) formed by polymerization of a polymerization component not containing a reactive functional group-containing monomer, and , 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) contains the non-reactive polar functional group-containing monomer (b1) .

Description

Adhesive composition, and an adhesive made using the same, and an adhesive for a polarizing plate {Adhesive composition and adhesive using same, and adhesive for polarizing plate}

The present invention relates to a pressure-sensitive adhesive composition, and a pressure-sensitive adhesive and a pressure-sensitive adhesive for a polarizing plate made using the same, and more specifically, a pressure-sensitive adhesive composition for forming an adhesive excellent in durability, light leakage resistance, rework property, transparency, and antistatic properties, the It relates to the adhesive formed by using, and the adhesive for polarizing plates.

Conventionally, both sides of a polyvinyl alcohol-based film or the like to which a polarization property has been imparted are coated with a protective film (generally, a triacetyl cellulose film, in addition to a film providing acryl, cycloolefin, olefin, retardation layer, etc.), for example 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. It is normal to carry out by contacting the said liquid crystal cell surface, and pressing the adhesive layer provided in the polarizing plate surface.

Such a polarizing plate typically has a three-layer structure in which both surfaces of a polyvinyl alcohol-based polarizer are sandwiched by a triacetyl cellulose-based protective film, but lacks dimensional stability from the characteristics of these materials. Moreover, since the polyvinyl alcohol-type polarizer is shape|molded by extending|stretching, it is easy to generate|occur|produce the dimensional change by the heat|fever of a backlight and the heat and humidity in an environment with time.

If the stress caused by such a dimensional change cannot be absorbed or alleviated, the distribution of residual stress acting on the adhesive layer and the polarizing plate becomes non-uniform. In particular, when the stress is concentrated in the periphery of the polarizing plate, birefringence or bending of the liquid crystal cell occurs in each member. The light leakage phenomenon occurs due to the above, or when the durability of the pressure-sensitive adhesive is low, lifting, peeling, foaming, or the like occurs due to the generated stress.

Therefore, with respect to the adhesive for attaching a polarizing plate, foaming or peeling does not occur with respect to the heat cycle from low temperature to high temperature under high temperature, high temperature and high humidity, and it is excellent in durability, and in addition to light leakage resistance, rework property, antistatic property Researches have been conducted on demanding adhesives with excellent balance in various performances such as , transparency and the like.

As an adhesive for a polarizing plate developed for this purpose, for example,

100 parts by mass of an acrylic resin (A) having a functional group, 100 to 500 parts by mass of an acrylic resin (B) not having a functional group, a crosslinking agent (C), and a silane coupling agent (D),

The acrylic resin (A) is a copolymer of 100 parts by mass of a (meth)acrylic ester monomer (a) and 0.1-5 parts by mass of a functional group-containing monomer (c) with a weight average molecular weight of 1 million to 2.5 million, the acrylic resin ( B) is a polymer with a weight average molecular weight of 1 million to 2.5 million of the (meth)acrylic ester monomer (b) that does not contain a functional group-containing monomer, and the monomer (a) and the monomer (b) are in the monomer composition. A pressure-sensitive adhesive composition for a polarizing plate characterized in that it is equal to or greater than 90% by mass (see Patent Document 1),

Contains a (meth)acrylic copolymer containing an alkyl (meth)acrylic acid ester monomer having an alkyl carbon number of 1 to 12, a gel fraction of 10 to 55%, an expansion ratio of 30 to 110, and eluted with ethyl acetate from an adhesive The weight average molecular weight of the obtained sol is 800,000 or more, and molecular weight distribution is 2.0-7.0, The acrylic adhesive composition for polarizing plates characterized by the above-mentioned (refer patent document 2) is mentioned.

JP 2011-122104 A JP 2009-507255 A

However, in recent years, with the enlargement of the image display device and the thinning of the member structure, the polarizing plate constituting the image display device is also required to have a good balance at a higher level in durability, light leakage resistance, reworkability, transparency, and antistatic properties. As a result, in the techniques of Patent Documents 1 and 2, there is still room for improvement in durability, and in particular, it is a test method under strict conditions among durability, and a problem remains in the durability performance in a heat cycle test more suitable for practicality.

Therefore, in the present invention, under such a background, when a polarizing plate and a glass substrate are attached, it is an adhesive that exhibits excellent durability (especially heat cycle resistance), and also has light leakage resistance, rework resistance, antistatic property, transparency ( It is intended to provide an adhesive excellent also in compatibility;

Therefore, the present inventors have conducted intensive research in view of such circumstances. As a result, the acrylic resin (A) containing the reactive functional group and the acrylic resin (B) not containing the reactive functional group are blended into a type of pressure-sensitive adhesive composition. In this case, by increasing the content of the reactive functional group in the acrylic resin (A) containing the reactive functional group more than usual, and by containing the polar functional group in the acrylic resin (B) that does not contain the reactive functional group, durability and light leakage resistance The present invention by discovering that a pressure-sensitive adhesive having excellent balance can be obtained, and also having excellent compatibility between the acrylic resin (A) containing a reactive functional group and the acrylic resin (B) not containing a reactive functional group came to completion.

That is, the present invention includes the following aspects (1) to (11).

(1) an acrylic resin (A) formed by polymerizing a polymerization component containing a reactive functional group-containing monomer (a1), an acrylic resin (B) formed by polymerization of a polymerization component not containing a reactive functional group-containing monomer It is a pressure-sensitive adhesive composition containing, 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) contains the non-reactive polar functional group-containing monomer (b1) A pressure-sensitive adhesive composition, characterized in that.

(2) 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, The pressure-sensitive adhesive composition according to (1) above.

(3) 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, The pressure-sensitive adhesive composition according to (1) or (2) above.

(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, in the above (1) to (3) The pressure-sensitive adhesive composition according to any one of them.

(5) The weight average molecular weight of acrylic resin (A) is 1 million or more, The adhesive composition in any one of said (1)-(4) characterized by the above-mentioned.

(6) The weight average molecular weight of acrylic resin (B) is 1 million or more, The adhesive composition in any one of said (1)-(5) characterized by the above-mentioned.

(7) The content ratio of the acrylic resin (A) and the acrylic resin (B) [(A): (B)] (weight ratio) is (A): (B) = 100: 50 to 100: 500, characterized in that The pressure-sensitive adhesive composition according to any one of (1) to (6) to be said.

(8) A crosslinking agent (C) is contained, The adhesive composition in any one of said (1)-(7) characterized by the above-mentioned.

(9) The cross-linking agent (C) is at least one selected from the group consisting of an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent, The pressure-sensitive adhesive composition according to (8) above.

(10) The pressure-sensitive adhesive composition according to any one of (1) to (9) is crosslinked with a crosslinking agent (C).

(11) The pressure-sensitive adhesive for a polarizing plate comprising the pressure-sensitive adhesive according to (10) above.

The pressure-sensitive adhesive obtained by using the pressure-sensitive adhesive composition of the present invention is an pressure-sensitive adhesive exhibiting excellent durability (particularly heat cycle resistance), and since it has excellent adhesion between an optical member such as a polarizing plate and a glass substrate, the pressure-sensitive adhesive layer and the glass substrate A liquid crystal display device in which foaming or peeling does not occur in between can be obtained.

In addition, 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 also excellent in transparency because it is excellent in compatibility between the acrylic resins to be blended.

Hereinafter, the present invention will be described in detail.

In addition, in the present invention, (meth)acryl means acryl or methacryl, (meth)acryloyl means acryloyl or methacryloyl, and (meth)acrylate means acrylate or methacrylate, respectively . In addition, an acrylic resin is resin obtained by superposing|polymerizing the polymerization component containing at least 1 sort(s) of (meth)acrylate-type monomer.

And the monomer in this invention is a compound which has a polymerizable unsaturated group, and such a polymerizable unsaturated group is not included in the functional group which a monomer has.

First, the acrylic resin (A) and acrylic resin (B) which the adhesive composition of this invention contains as an essential component are demonstrated.

The acrylic resin (A) is formed by polymerizing a polymerization component containing 2.5 to 30% by weight of a reactive functional group-containing monomer (a1), and, if necessary, a (meth)acrylic acid alkylester-based monomer (a2) or other copolymerizable ethylene A sexually unsaturated monomer (a3) may be included as a copolymerization component.

The reactive functional group in the reactive functional group-containing monomer (a1) refers to a crosslinking agent (C), which will be described later, under general crosslinking reaction conditions (for example, without a catalyst, at 60° C. or lower) under reactivity (with or without increase in gel fraction). ), and the reactive functional group-containing monomer (a1) is a monomer containing a functional group that can serve as a crosslinking point when the acrylic resin (A) reacts with the crosslinking agent (C).

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 acetacetyl group-containing monomer, an isocyanate group-containing monomer, a glycidyl group-containing monomer, and the like. Among these, a hydroxyl-containing monomer and a carboxyl group-containing monomer are preferable at the point which can crosslinking-react efficiently with various crosslinking agents.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. ) Acrylic acid hydroxyalkyl esters such as acrylate and 8-hydroxyoctyl (meth)acrylate, caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth)acrylate, diethylene glycol (meth)acrylate , oxyalkylene-modified monomers such as polyethylene glycol (meth) acrylate, other 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid, N-methylol (meth) acrylamide, hydroxyethyl acrylamide, etc. primary hydroxyl group-containing monomers; secondary hydroxyl group-containing monomers such as 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-chloro2-hydroxypropyl (meth)acrylate; and tertiary hydroxyl group-containing monomers such as 2,2-dimethyl 2-hydroxyethyl (meth)acrylate.

Among the hydroxyl group-containing monomers, primary hydroxyl group-containing monomers are preferable from the viewpoint of excellent reactivity with a crosslinking agent, and monomers having hydroxyl groups at the molecular chain terminal are preferable because they tend to exhibit superior antistatic performance. Moreover, it is especially preferable to use 2-hydroxyethyl acrylate from a viewpoint that there are few impurities, such as di(meth)acrylate, and it is easy to manufacture.

In addition, as the hydroxyl group-containing monomer used in the present invention, it is also preferable to use a compound having an impurity di(meth)acrylate content of 0.5% or less, and 0.2% or less, particularly 0.1% or less. are preferable, 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, polyacrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, Cinnamon acid etc. are mentioned, Among these, (meth)acrylic acid is used preferably.

As said acetacetyl group containing monomer, 2-(acetacetoxy) ethyl (meth)acrylate, allyl acetacetate, etc. are mentioned, for example.

As said isocyanate group containing monomer, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, these alkylene oxide adducts, etc. are mentioned, for example.

As said glycidyl group containing monomer, glycidyl (meth)acrylate, allylglycidyl (meth)acrylate, etc. are mentioned, for example.

These reactive functional group containing monomers (a1) may be used independently and may use 2 or more types together. Especially, it is preferable to use together a hydroxyl-containing monomer and a carboxyl-group containing monomer at the point excellent in the reactivity with a crosslinking agent, and storage stability.

When using a hydroxyl-containing monomer and a carboxyl group-containing monomer together, it is preferable that the content rate makes more the ratio of a carboxyl group-containing monomer than a hydroxyl-containing monomer from a viewpoint excellent in durability.

The content of the reactive functional group-containing monomer (a1) needs to be 2.5 to 30% by weight with respect to the entire polymerization component, preferably 3 to 25% by weight, particularly preferably 3 to 20% by weight, more preferably is 3.5 to 15% by weight.

When the content of the reactive functional group-containing monomer (a1) is too large, the rework property is lowered or the stress relaxation property is lowered to deteriorate the light leakage resistance or warp of the substrate tends to occur. When the content is too small, the durability is lowered.

As said (meth)acrylic acid alkylester type monomer (a2), carbon number of an alkyl group is normally 1-20, Preferably it is 1-18, Especially preferably, it is 1-12, More preferably, it is 1-8, for example. 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. are mentioned. These may be used independently and may use 2 or more types together.

Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferable from the viewpoint of versatility and adhesion physical properties, and these It is preferable to have a monomer as a main component.

The content of the (meth)acrylic acid alkylester-based 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. am.

When such a content is too small, there exists a tendency for resin price to become high, and there exists a tendency for it to become difficult to balance adhesive physical properties, and when too large, there exists a tendency for cohesion force to fall or light leakage resistance to fall.

As said other copolymerizable ethylenically unsaturated monomer (a3), For example, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, 2-hydroxy-3 - Aromatic ring-containing monomers, such as phenoxypropyl (meth)acrylate and orthophenyl phenoxyethyl (meth)acrylate;

Cyclohexyl (meth) acrylate, cyclohexyloxyalkyl (meth) acrylate, t-butylcyclohexyloxyethyl (meth) acrylate isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyl alicyclic-containing monomers such as (meth)acrylate and isobornyl (meth)acrylate;

Methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, isopropoxymethyl (meth) acrylamide, n-butoxymethyl (meth) acrylamide, isobutoxy Alkoxyalkyl (meth)acrylamide monomers such as methyl (meth)acrylamide, (meth)acryloylmorpholine, dimethyl (meth)acrylamide, diethyl (meth)acrylamide, (meth)acrylamide N-methyl Amide-based monomers, such as (meth)acrylamide-type monomers, such as all (meth)acrylamide;

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 Ether chain containing (meth) acrylate, such as glycol (meth) acrylate, octosy polyethylene glycol polypropylene glycol mono (meth) acrylate, lauroxy polyethylene glycol mono (meth) acrylate, stearic polyethylene glycol mono (meth) acrylate 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, fumarate dialkyl ester , allyl alcohol, acryl chloride, methyl vinyl ketone, N-acrylamide methyl trimethyl ammonium chloride, allyl trimethyl ammonium chloride, dimethyl allyl vinyl ketone, and the like. These are used individually or in combination of 2 or more types.

Among these, from the viewpoint of easy adjustment of refractive index and adjustment of birefringence, an aromatic ring-containing monomer is preferable, and particularly preferably benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol ( It is a meth)acrylate, and it is easy to adjust the refractive index and adjust the birefringence, and from the viewpoint of excellent adhesion to the low-polar adherend (olefin substrate), an alicyclic-containing monomer is preferable, and the adhesion and cohesive force to the substrate and adherend, the resin From a viewpoint of being easy to adjust compatibility, an amide-type monomer is preferable.

The content of the other copolymerizable ethylenically unsaturated monomers (a3) is preferably 0 to 50% by weight, particularly preferably 0 to 50% by weight, based on the entire polymerization component, when (a3) is an aromatic ring-containing monomer or an alicyclic-containing monomer. is 5 to 40% by weight, more preferably 10 to 30% by weight. When there is too much such content, it is difficult to adjust birefringence, and there exists a tendency for the light leakage suppression effect to fall.

Moreover, when (a3) is anything other than an aromatic ring containing monomer and an alicyclic containing monomer, with respect to the whole polymerization component, Preferably it is 0 to 10 weight%, Especially preferably, it is 0 to 5 weight%. When there is too much such content, there exists a tendency for the long-term storage stability of acrylic resin (A) to fall or to become easy to gelatinize at the time of superposition|polymerization.

The acrylic resin (A) used in the present invention is a reactive functional group-containing monomer (a1), if necessary, a (meth)acrylic acid alkylester-based monomer (a2) or other copolymerizable ethylenically unsaturated monomers (a3) containing It can manufacture by selecting and using a copolymerization component suitably and superposing|polymerizing. In the case of the said polymerization, it can carry out by conventionally well-known methods, such as solution radical polymerization, suspension polymerization, block polymerization, and emulsion polymerization.

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 to perform polymerization under predetermined polymerization conditions. Among 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, isopropyl alcohol, etc. and ketones such as aliphatic alcohols, 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 preferable, and more preferably, from the viewpoint of easiness of polymerization reaction, effect of chain transfer, easiness of drying during adhesive coating, and safety. is ethyl acetate, acetone, or methyl ethyl ketone.

Moreover, as a polymerization initiator used for such radical polymerization, For example, 2,2'- azobisisobutyronitrile which is a normal radical polymerization initiator, 2,2'- azobis-2-methylbutyronitrile; Azo initiators such as 4,4'-azobis(4-cyanovaleric acid) and 2,2'-azobis(methylpropionic acid), benzoyl peroxide, lauryl peroxide, di-t-butyl peroxide, cumene Organic peroxides, such as a hydroperoxide, etc. are mentioned, According to the monomer to be used, it can select and use it suitably. These solvents are used individually or in combination of 2 or more types.

It is preferable that it is 600,000 or more, as for the minimum of the weight average molecular weight of the said acrylic resin (A), 800,000 or more are more preferable, More preferably, it is 1 million or more. Moreover, it is preferable that it is 2.5 million or less, as for the upper limit of the weight average molecular weight of acrylic resin (A), 1.8 million or less are more preferable, More preferably, it is 1.6 million or less.

When such a weight average molecular weight is too small, durability tends to fall, and when a weight average molecular weight is too large, a dilution solvent is required in large quantity at the time of manufacture, and there exists a tendency for drying property to fall.

It is preferable that the dispersion degree (weight average molecular weight/number average molecular weight) of the said acrylic resin (A) is 30 or less, More preferably, it is 15 or less, More preferably, it is 7 or less, Especially preferably, it is 5 or less.

When such a degree of dispersion is too high, there exists a tendency for cohesion force to fall easily. In addition, the lower limit of such a dispersion degree is 1.

In addition, the said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, and high performance liquid chromatography (Nippon Waters Co., Ltd. make, "Waters2695 (main body)" and "Waters 2414 (detector)"), column: Shodex GPC KF-806L (exclusion limit molecular weight: 2×10 ⁷ , separation range: 100 to 2×10 ⁷ , number of theoretical plates: 10,000 steps/piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) It is measured by the measurement conditions of about 1 mg/ml of sample concentration, developing solvent: THF, and flow rate: 1 ml/min using three series, and a number average molecular weight can also be measured by the same method. Moreover, dispersion degree can be calculated|required from a weight average molecular weight and a number average molecular weight.

It is preferable that the glass transition temperature (Tg) of the said acrylic resin (A) is -80-0 degreeC, More preferably, it is -60--15 degreeC, More preferably, it is -60--20 degreeC.

When such a glass transition temperature is too high, there exists a tendency for a tack to fall easily, and when too low, there exists a tendency for heat resistance to fall.

In addition, the said glass transition temperature is computed by the formula of the following Fox.

1/Tg=w1/Tg1+w2/Tg2+...Wk/Tgk

However, in the above formula, 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, w1+w2+... wk=1.

The refractive index of the said acrylic resin (A) should just be 1.440-1.600 normally, Preferably it is 1.440-1.550, Especially preferably, it is 1.440-1.500. It is preferable to reduce the difference between the refractive index and the refractive index of the members to be laminated because the optical loss at the member interface is reduced.

The said refractive index is the value which measured the acrylic resin with NaD line using the refractive index measuring apparatus ("Abbe refractometer 1T" manufactured by Atago Corporation).

It is preferable that the haze of the said acrylic resin (A) is 1.0 % or less, More preferably, it is 0.8 % or less, Especially preferably, it is 0.5 % or less. When the haze is too high, the image quality of the display tends to deteriorate. In addition, as a lower limit of such a haze, it is 0.01 % normally.

In this way, the acrylic resin (A) used by invention is obtained.

The acrylic resin (B) is an acrylic resin (B) formed by polymerizing a polymerization component that does not contain a reactive functional group-containing monomer, and the polymerization component contains a non-reactive polar functional group-containing monomer (b1) as an essential component, and is required In some cases, the (meth)acrylic acid alkyl ester-based monomer (b2) or other copolymerizable ethylenically unsaturated monomer (b3) may be included as a copolymerization component.

In addition, the reactivity and non-reactivity in the said acrylic resin (B) are the same as the reactivity in the acrylic resin (A), under general crosslinking reaction conditions with respect to the crosslinking agent (C) mentioned later (for example, no catalyst) Below, 60° C. or less) and non-reactive (it can be confirmed by the presence or absence of an increase in the gel fraction).

As the non-reactive polar functional group-containing monomer (b1), for example, when the crosslinking agent is an isocyanate group-containing crosslinking agent, an acetacetoxy group-containing monomer, a tertiary amino group (amino group containing no active hydrogen)-containing monomer, and an amide group containing monomers, epoxy group-containing monomers, and ether group-containing monomers;

When the crosslinking agent is a carboxyl group-containing crosslinking agent, examples thereof 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, carboxyl group-containing monomers, carboxylic acid anhydride-containing monomers, and acetacetoxy group-containing monomers are exemplified;

When the crosslinking agent is a hydroxyl group-containing crosslinking agent, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, a glycidyl group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, and an ether group-containing monomer are mentioned;

When the crosslinking agent is a glycidyl group-containing crosslinking agent, tertiary amino group (amino group containing no active hydrogen) containing monomer, amide group containing monomer, ether group containing monomer, isocyanate group containing monomer, epoxy group containing monomer, hydroxyl group containing monomer, acetone and an acetoxy group-containing monomer.

These non-reactive polar functional group containing monomers (b1) may be used independently and may use 2 or more types together.

Among these, the (meth)acrylate-based monomer of each monomer is preferable, and specifically, (meth)acrylate containing an amide group, (meth)acrylate containing a tertiary amino group (amino group containing no active hydrogen), ether A group-containing (meth)acrylate is preferable, and particularly preferably, it is an amide group-containing (meth)acrylate from the viewpoint of excellent compatibility with the acrylic resin (A) and durability.

As said amide group containing (meth)acrylate, for example, methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, propoxymethyl (meth)acrylamide, isopropoxymethyl (meth)acrylamide Alkoxyalkyl (meth)acrylamide monomers such as amide, n-butoxymethyl (meth) acrylamide, isobutoxymethyl (meth) acrylamide, (meth) acryloylmorpholine, dimethyl (meth) acrylamide, di (meth)acrylamide type monomers, such as ethyl (meth)acrylamide and (meth)acrylamide N-methylol (meth)acrylamide, etc. are mentioned.

Among these, dialkyl (meth)acrylamide is preferable from the viewpoint of stability at the time of polymerization and stability at the time of storage, and dimethylacrylamide is particularly preferable from the viewpoint of high molecular weight.

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

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)acrylic Rate, methoxydipropylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, octooxy polyethylene glycol polypropylene glycol mono (meth) acrylate, lauroxy polyethylene glycol mono (meth) acrylate, stearic polyethylene Ether chain containing (meth)acrylates, such as glycol mono(meth)acrylate, etc. are mentioned.

The content of the non-reactive polar functional group-containing monomer (b1) is preferably 0.1 to 30% by weight, particularly preferably 0.5 to 30% by weight, more preferably 1 to 25% by weight, based on the entire polymerization component, Especially preferably, it is 3 to 25 weight%.

When the content of the non-reactive polar functional group-containing monomer (b1) is too large, the heat-and-moisture resistance tends to decrease or the stability during storage tends to decrease, and when too small, the compatibility with the acrylic resin (A) tends to decrease. .

As said (meth)acrylic acid alkylester type monomer (b2), the thing similar to the (meth)acrylic acid alkylester type monomer (a2) demonstrated above can be illustrated, For example, carbon number of an alkyl group is usually 1-20, and it is preferable. preferably 1 to 18, particularly preferably 1 to 12, more preferably 1 to 8, and 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, isostearyl (meth) acrylate, etc. can be heard These may be used independently and may use 2 or more types together.

Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferable from the viewpoint of versatility and adhesive physical properties, and these monomers are It is preferable to set it as a main component.

The content of the (meth)acrylic acid alkylester-based monomer (b2) is preferably 60 to 99.9% by weight, particularly preferably 70 to 99.5% by weight, and still more preferably 75 to 95% by weight based on the entire polymerization component. am.

When such content is too small, compatibility with the reactive functional group-containing acrylic resin (A) tends to decrease, the resin price tends to increase, and even if too large, compatibility with the reactive functional group-containing acrylic resin (A) decreases. tends to

As said 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 alicyclic-containing monomers such as (meth)acrylate and isobornyl (meth)acrylate;

Acrylonitrile, methacrylonitrile, vinyl acetate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyltoluene, vinylpyrrolidone, methyl vinyl ketone, dimethyl allyl vinyl ketone, etc. are mentioned. These are used individually or in combination of 2 or more types.

Among these, from the viewpoint of easy adjustment of refractive index and adjustment of birefringence, an aromatic ring-containing monomer is preferable, and particularly preferably benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth ) An alicyclic-containing monomer is preferable from a viewpoint of being easy to adjust an acrylate, refractive index, and adjustment of birefringence, and is excellent in adhesiveness to a low-polarity to-be-adhered body (cycloolefin).

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

Moreover, when (b3) is things other than an aromatic ring containing monomer and an alicyclic containing monomer, with respect to the whole polymerization component, Preferably it is 0 to 10 weight%, Especially preferably, it is 0 to 5 weight%. When there is too much such content, there exists a tendency for the long-term storage stability of an acrylic resin (B) to fall or the compatibility of an acrylic resin (A) and an acrylic resin (B) to fall.

The acrylic resin (B) used in the present invention is a non-reactive polar functional group-containing monomer (b1), if necessary, a (meth)acrylic acid alkylester-based monomer (b2) or other copolymerizable ethylenically unsaturated monomers (b3) It can manufacture by appropriately selecting, using, and superposing|polymerizing the copolymerization component to contain. The polymerization can be carried out by conventionally known methods such as solution radical polymerization, suspension polymerization, bulk polymerization, and emulsion polymerization.

For example, in an organic solvent, a polymerization component containing a non-reactive polar functional group-containing monomer (b1) and a polymerization initiator are mixed or dropped to perform polymerization under predetermined polymerization conditions. Among 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, isopropyl alcohol, etc. and ketones such as aliphatic alcohols, 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 preferable, and more preferably, from the viewpoints of the easiness of the polymerization reaction, the effect of chain transfer, the easiness of drying during adhesive coating, and safety. is ethyl acetate, acetone, or methyl ethyl ketone.

Moreover, as a polymerization initiator used for such radical polymerization, For example, 2,2'- azobisisobutyronitrile which is a normal radical polymerization initiator, 2,2'- azobis-2-methylbutyronitrile; Azo initiators such as 4,4'-azobis(4-cyanovaleric acid) and 2,2'-azobis(methylpropionic acid), benzoyl peroxide, lauryl peroxide, di-t-butyl peroxide, cumene Organic peroxides, such as a hydroperoxide, etc. are mentioned, According to the monomer to be used, it can select and use it suitably. These solvents are used individually or in combination of 2 or more types.

It is preferable that it is 600,000 or more, as for the minimum of the weight average molecular weight of the said acrylic resin (B), 800,000 or more are more preferable, More preferably, it is 1 million or more. Moreover, it is preferable that it is 2.5 million or less, as for the upper limit of the weight average molecular weight of acrylic resin (B), 1.8 million or less are more preferable, More preferably, it is 1.6 million or less. When such a weight average molecular weight is too small, durability tends to fall, and when a weight average molecular weight is too large, a dilution solvent is required in large quantity at the time of manufacture, and there exists a tendency for drying property to fall.

It is preferable that the dispersion degree (weight average molecular weight/number average molecular weight) of the said acrylic resin (B) is 30 or less, More preferably, it is 15 or less, More preferably, it is 7 or less, Especially preferably, it is 5 or less.

When such a degree of dispersion is too high, there exists a tendency for cohesion force to fall easily. In addition, the lower limit of such a dispersion degree is 1.

In addition, the measuring method of said weight average molecular weight is as mentioned above.

It is preferable that the glass transition temperature (Tg) of the said acrylic resin (B) is -80-0 degreeC, More preferably, it is -60--10 degreeC, More preferably, it is -60--20 degreeC.

When such a glass transition temperature is too high, there exists a tendency for a tack to fall easily, and when too low, there exists a tendency for heat resistance to fall.

In addition, the measuring method of the said glass transition temperature is as mentioned above.

What is necessary is just to adjust the refractive index of the said acrylic resin (B) in the range of 1.440-1.600 normally, Preferably it is 1.440-1.550, Especially preferably, it is 1.440-1.500. It is preferable to reduce the difference between the refractive index and the refractive index of the members to be laminated because the optical loss at the member interface is reduced. The measuring method of the said refractive index is as mentioned above.

It is preferable that the haze of the said acrylic resin (B) is 1.0 % or less, More preferably, it is 0.8 % or less, Especially preferably, it is 0.5 % or less.

When the haze is too high, the image quality of the display tends to deteriorate. In addition, as a lower limit of a haze, it is 0.01 % normally.

In this way, the acrylic resin (B) used by this invention is obtained.

The adhesive composition of this invention contains the said acrylic resin (A) and an acrylic resin (B) as essential structural components.

As a content ratio ((A):(B) (weight ratio) of the said acrylic resin (A) and an acrylic resin (B), it is preferable that it is (A):(B)=100:50-100:500, and it is more preferable Preferably (A):(B)=100:100-100:400, More preferably, it is 100:100-100:350.

When the content ratio of the acrylic resin (B) to the acrylic resin (A) is too high, the degree of crosslinking tends to be low and the cohesive force decreases.

And it is preferable that the adhesive composition of this invention contains a crosslinking agent (C), It bridge|crosslinks with a crosslinking agent (C), and becomes an adhesive.

As said crosslinking agent (C), an isocyanate type crosslinking agent, an epoxy type crosslinking agent, an aziridine type crosslinking agent, a melamine type crosslinking agent, an aldehyde type crosslinking agent, an amine type crosslinking agent, and a metal chelate type crosslinking agent are mentioned, for example. Among these, an isocyanate type crosslinking agent and an epoxy type crosslinking agent are preferable from a viewpoint of being excellent in durability and light leakage resistance.

Examples of the isocyanate-based crosslinking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, and hexamethylene diisocyanate. Isocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, tetramethylxylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane tri Isocyanate and the adduct body of these polyisocyanate compounds and polyol compounds, such as trimethylol propane, the biuret body of these polyisocyanate compounds, an isocyanurate body, etc. are mentioned. Among them, an adduct body of 2,4-tolylene diisocyanate with trimethylolpropane is preferable from the viewpoint of having a particularly long pot life and excellent compatibility with resin.

As said epoxy-type crosslinking agent, For example, a bisphenol A-epicrolhydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethyleneglycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether , 1,6-hexanediol diglycidyl ether, trimethylol propane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol Polyglycidyl ether etc. are mentioned. Among them, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane and N,N,N'N'-tetraglycidyl-m-xylenediamine are particularly preferred from the viewpoint of high reactivity. desirable.

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

Examples of the melamine-based crosslinking agent include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaputoxymethylmelamine, hexapentyloxymethylmelamine, hexahexyloxymethylmelamine, melamine resin, and the like. can be heard

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

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

Examples of the metal chelate 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

Moreover, these crosslinking agents (C) may be used independently and can also use 2 or more types together. It is preferable from a durable viewpoint to use an isocyanate type crosslinking agent and an epoxy type crosslinking agent together.

It is preferable that content of the said crosslinking agent is 0.1-15 weight part with respect to 100 weight part of acrylic resin (A), More preferably, it is 0.3-10 weight part, More preferably, it is 0.5-10 weight part, Especially preferably, 1.0 to 7.5 parts by weight.

When there are too few crosslinking agents, there exists a tendency for durability to fall, and when too large, there exists a tendency for stress relaxation property to fall or to require aging for a long time.

In the adhesive composition of this invention, it is preferable from a viewpoint that the adhesiveness with respect to an optical member improves that containing a silane coupling agent (D) further, and containing an antistatic agent (E) is antistatic property at the time of peeling It is preferable from an excellent viewpoint.

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, a carboxyl group-containing silane coupling agent, An amino group-containing silane coupling agent, an amide group-containing silane coupling agent, an isocyanate group-containing silane coupling agent, and the like can be given. These may be used independently and may use 2 or more types together. Among these, an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent are preferably used, and the use of an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent together also improves moist heat durability and does not increase the adhesive strength too much. It is preferable from the point of view

Further, an oligomeric silane compound partially hydrolyzed and polycondensed is also preferable from the viewpoint of excellent durability and reworkability.

Specific examples of the epoxy group-containing silane coupling agent include, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidyl Cydoxypropylmethyldimethoxysilane, methyltri(glycidyl)silane, β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, etc. Among them, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4 epoxycyclohexyl) are preferred. ) is ethyltrimethoxysilane.

Specific examples of the mercapto group-containing silane coupling agent include, for example, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyldimethoxymethylsilane, SH group-containing silicone An alkoxy oligomer (mercapto group-modified ethyl/methyl silicate low-condensate) etc. are mentioned.

As content of the said silane coupling agent (D), it is 0.001-10 weight part normally with respect to a total of 100 weight part of acrylic resin (A) and acrylic resin (B), Preferably it is 0.01-1 weight part, Especially preferably is 0.02 to 0.5 parts by weight.

When the content of such a silane coupling agent (D) is too small, the effect of addition tends not to be obtained, and when too much, the adhesiveness of the pressure-sensitive adhesive rises too much, and the rework property is lowered or bleed out to the pressure-sensitive adhesive surface, resulting in reduced durability tends to

Examples of the antistatic agent (E) include an imidazorium salt, a cationic antistatic agent of a quaternary ammonium salt such as tetraalkylammonium sulfonate, an aliphatic sulfonate, a higher alcohol sulfate ester salt, and a higher alcohol alkylene oxide adduct Anionic antistatic agents such as sulfuric acid ester salt, higher alcohol phosphoric acid ester salt, higher alcohol alcohol alkylene oxide adduct phosphoric acid ester salt, potassium bis(fluorosulfonyl) imide, lithium bis (trifluorosulfonyl) imide or chloride Alkali metal salts, such as lithium, alkaline-earth metal salt, higher alcohol alkylene oxide adduct, polyalkylene glycol fatty acid ester, etc. are mentioned.

As content of the said antistatic agent (E), it is 0.1-10 weight part normally with respect to a total of 100 weight part of acrylic resin (A) and acrylic resin (B), Preferably it is 0.5-5 weight part, Especially preferably 0.5 to 3 parts by weight.

When there is too little content of such said antistatic agent (E), there exists a tendency which an addition effect cannot be acquired, and when too much, it bleeds on the adhesive surface and there exists a tendency for durability to fall.

Moreover, in the adhesive composition of this invention, in the range which does not impair the effect of this invention, other acrylic adhesives, other adhesives, urethane resin, rosin, rosin ester, hydrogenated rosin ester, phenol resin, aliphatic petroleum resin, alicyclic type Various additives such as petroleum resins and tackifiers such as styrene resins, colorants, fillers, antioxidants, ultraviolet absorbers and functional dyes, and compounds that cause coloration or discoloration by irradiation with ultraviolet rays or radiation can be blended. Further, in addition to the above additives, a small amount of impurities, etc. included in the raw materials for manufacturing the constituent components of the pressure-sensitive adhesive composition may be contained. These blending amounts can be appropriately set so that desired physical properties may be obtained.

The adhesive composition of the present invention can be made into an adhesive by crosslinking (curing), and by laminating and forming an adhesive layer made of such an adhesive on an optical member (optical laminate), an adhesive layer laminated optical member can be obtained. .

It is preferable to provide a release sheet again in the surface opposite to the optical member surface of an adhesive layer in the said adhesive layer lamination|stacking optical member.

As a manufacturing method of the said adhesive layer lamination|stacking optical member, when an adhesive composition performs hardening by at least one of active energy ray irradiation and heating, [1] apply|coats an adhesive composition on an optical member, dries, and mold release A method of attaching a sheet and performing a treatment by at least one of irradiation with active energy rays and aging at room temperature or a warm state, [2] Applying an adhesive composition on a release sheet and drying, attaching an optical member, active energy A method of performing treatment by at least one of irradiation with radiation and aging at room temperature or a warm state, [3] Applying and drying the pressure-sensitive adhesive composition on the optical member, followed by irradiation with active energy rays and aging at room temperature or warming After performing the treatment by at least one, the method of attaching the release sheet, [4] coating the pressure-sensitive adhesive composition on the release sheet, drying, and further treatment by at least one of active energy ray irradiation and aging at room temperature or heated condition After carrying out, there is a method of attaching an optical member.

Among these, the method [2] is preferable in that aging at room temperature does not damage the substrate and excellent in adhesion to the substrate.

Such an aging treatment is performed to balance the physical properties of the adhesive as a reaction time for chemical crosslinking of the pressure-sensitive adhesive. As conditions for aging, the temperature is usually room temperature to 70° C., and the time is usually 1 to 30 days, specifically may be carried out under conditions such as, for example, 1 day to 20 days at 23°C, 3 days to 10 days at 23°C, and 1 day to 7 days at 40°C.

At the time of application|coating of the said adhesive composition, it is preferable to apply|coat this adhesive composition by dilution with a solvent, As a dilution density|concentration, Preferably it is 5 to 60 weight% as heating residual density|concentration, More preferably, it is 10 to 30 weight%. The solvent is not particularly limited as long as it dissolves the pressure-sensitive adhesive composition, and for example, ester solvents such as methyl acetate, ethyl acetate, methyl acetate, ethyl acetate, acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ketone solvents, such as aromatic solvents, such as toluene and xylene, alcohol solvents, such as methanol, ethanol, and propyl alcohol, can be used. Among them, ester solvents, particularly ethyl acetate and ketone solvents, particularly methyl ethyl ketone, are suitably used from the viewpoints of solubility, dryness, price, and the like.

Moreover, regarding application|coating of the said adhesive composition, it is implemented by conventional methods, such as roll coating, die coating, gravure coating, comma coating, and 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 to 80% from the viewpoint of durability and light leakage prevention performance. %am. When the gel fraction is too low, the durability due to the lack of cohesive force tends to be insufficient. Moreover, when a gel fraction is too high, a tack|tack will become insufficient by the raise of cohesive force, and there exists a tendency for floatation and peeling to occur easily.

Moreover, it is preferable that the gel fraction measured by the said measurement is 10% or more higher than the ratio which the weight in which the acrylic resin (A) and the crosslinking agent (C) faced in an adhesive account for the weight of the whole adhesive, More preferably, 15 % or more When it is too low, there exists a tendency for durability to fall.

The pressure-sensitive adhesive layer produced by the above method is preferable because it tends to increase the workability because it has good wettability when the pressure-sensitive adhesive layer is applied to an adherend when it is touched with a finger.

In addition, when adjusting the gel fraction of the adhesive for optical members to the said range, for example, adjusting the amount and type of a crosslinking agent; Adjusting the mixing|blending ratio of an acrylic resin (A) and an acrylic resin (B); Acrylic resin Adjusting the amount and type of functional groups of (A); Adjusting the molecular weight of the acrylic resin (A) and/or the acrylic resin (B); etc. are achieved.

The gel fraction is a criterion for the degree of crosslinking (degree of curing), and is, for example, calculated by the following method. That is, about 0.1 g of the pressure-sensitive adhesive layer is scraped off from the pressure-sensitive adhesive sheet (with no separator installed) formed with the pressure-sensitive adhesive layer on the polarizing plate serving as the substrate, and the pressure-sensitive adhesive layer is wrapped with a 200-mesh SUS wire mesh and placed in ethyl acetate at 23°C × After immersion for 24 hours, the weight percentage of the insoluble pressure-sensitive adhesive component remaining in the wire mesh is taken as the gel fraction.

Moreover, 5-300 micrometers is preferable, especially 10-50 micrometers is preferable, and, as for the thickness of the adhesive layer in the adhesive layer lamination|stacking optical member obtained, 10-30 micrometers is preferable. When the thickness of this adhesive layer is too thin, there exists a tendency for adhesive physical properties to be difficult to stabilize, and when too thick, there exists a tendency for rework property to fall or the thickness of the whole optical member will increase too much.

The adhesive layer lamination|stacking optical member of this invention sticks an adhesive layer surface to a glass substrate, after peeling a release sheet directly or what has a release sheet, and is provided, for example to a liquid crystal display board.

The initial adhesive force of the adhesive layer of this invention is suitably determined according to the material etc. of a to-be-adhered body. For example, when sticking to a glass substrate, it is preferable to have the adhesive force of 0.2N/25mm - 15N/25mm, More preferably, it is 0.5N/25mm - 10N/25mm, More preferably, it is 1N/ 25mm to 10N/25mm.

The said initial adhesive force is computed as follows. The pressure-sensitive adhesive layer laminated polarizing plate is cut to a width of 25 mm, the release film is peeled, and the pressure-sensitive adhesive layer side is pressed against an alkali-free glass plate (“Eagle XG” manufactured by Corning Corporation), and the polarizing plate and the glass plate are attached. Thereafter, after autoclave treatment (50° C., 0.5 MPa, 20 minutes), and leaving it to stand at 23° C. and 50% RH for 24 hours, 180° C. peeling test is performed.

It does not specifically limit as an optical member in this invention, An optical film used suitably for image display apparatuses, such as a liquid crystal display device, an organic electroluminescent display device, PDP, For example, a polarizing plate, retardation plate, an elliptically polarizing plate, An optical compensation film, a brightness improving film, and the thing in which these are laminated|stacked etc. are mentioned. Especially, it is effective in this invention that it is a polarizing plate.

The polarizing plate used in the present invention is usually one in which a triacetyl cellulose (TAC)-based film is laminated on both surfaces of a polarizing film as a protective film, and the polarizing film has an average degree of polymerization of 1,500 to 10,000 and a degree of saponification of 85 to 100 mole % of a polyvinyl alcohol-based resin as a raw film, and a uniaxially stretched film dyed with an aqueous solution of iodine-potassium iodide or a dichroic dye (usually stretched by 2 to 10 times, preferably 3 to 7 times). magnification) is used.

The polyvinyl alcohol-based resin is usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but a small amount of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins, vinyl ethers, unsaturated It may contain components copolymerizable with vinyl acetate, such as a sulfonate. Moreover, so-called polyvinyl acetal resin and polyvinyl alcohol derivative|guide_body, such as polybutyral resin and polyvinyl formal resin, which made polyvinyl alcohol react with aldehydes in presence of an acid are mentioned, for example.

In addition to the triacetyl cellulose film normally used as a protective film for the said polarizing plate, an acryl-type film, a polyethylene-type film, a polypropylene-type film, a cycloolefin-type film, etc. are mentioned.

Moreover, for thin film formation, the side protective film polarizing plate which removed the protective film of the side pasted on an optical member is also mentioned.

(Example)

Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example unless the summary is exceeded. In addition, in the Example, "part" and "%" mean a weight basis.

First, various acrylic resins were prepared as follows. In addition, about the measurement of the weight average molecular weight, dispersion degree, glass transition temperature, and refractive index of an acrylic resin (A) and an 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)]

<Production of acrylic resin (A-1)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 86.5 parts of butyl acrylate (BA) (a2), 10 parts of benzyl acrylate (BzA) (a3), 10 parts of 2-hydro 0.5 parts of oxyethyl acrylate (HEA) (a1), 3 parts of acrylic acid (AAc) (a1), 47.2 parts of ethyl acetate, 42 parts of acetone, 0.013 parts of azobis isobutyronitrile (AIBN) as a polymerization initiator are added, and appropriately After reacting at reflux temperature for 3.25 hours while adding AIBN and ethyl acetate, dilute with ethyl acetate to obtain an acrylic resin (A-1) solution (weight average molecular weight 1.5 million, dispersity 3.1, glass transition temperature -48°C, solid content concentration 19.5% , a viscosity of 4580 mPa·s (25° C.), and a refractive index of 1.477) were obtained.

<Production of acrylic resin (A-2)>

In a four-mouth round-bottomed flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 84.5 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate (a1) ) 0.5 parts, acrylic acid (a1) 5 parts, ethyl acetate 47.2 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 parts as a polymerization initiator, AIBN and ethyl acetate are added appropriately, and reacted at reflux temperature for 3.25 hours. Then, diluted with ethyl acetate to a solution of acrylic resin (A-2) (weight average molecular weight 1.5 million, dispersion degree 3.3, glass transition temperature -46 ° C, solid content concentration 19.9%, viscosity 5640 mPa s (25 ° C), refractive index 1.478) got

<Production of acrylic resin (A-3)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 82 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate (a1 ) 0.5 parts, acrylic acid (a1) 7.5 parts, ethyl acetate 47.2 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 parts as a polymerization initiator, AIBN and ethyl acetate are added appropriately, and reacted for 3.25 hours at reflux temperature. Then, dilute with ethyl acetate to give an acrylic resin (A-3) solution (weight average molecular weight 1.4 million, dispersion degree 3.6, glass transition temperature -43 ° C, solid content concentration 19.9%, viscosity 6380 mPa s (25 ° C), refractive index 1.479) got

<Production of acrylic resin (A-4)>

In a four-mouth round-bottomed flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 84.4 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate (a1 ) 0.6 parts, acrylic acid (a1) 5 parts, ethyl acetate 47.2 parts, acetone 42 parts, and azobisisobutyronitrile (AIBN) 0.013 parts as a polymerization initiator are added, and AIBN and ethyl acetate are appropriately added while reacting at reflux temperature for 3.25 hours. Then, diluted with ethyl acetate to a solution of acrylic resin (A-4) (weight average molecular weight 1.5 million, dispersion degree 3.8, glass transition temperature -46 ° C, solid content concentration 19.9%, viscosity 6380 mPa s (25 ° C), refractive index 1.478) got

<Production of acrylic resin (A-5)>

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

<Production of acrylic resin (A-6)>

Into a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 62.4 parts of butyl acrylate (a2), 30 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate (a1 ) 0.6 parts, acrylic acid (a1) 7 parts, ethyl acetate 48.3 parts, acetone 37.5 parts, and azobisisobutyronitrile (AIBN) 0.013 parts as a polymerization initiator, AIBN and ethyl acetate are added appropriately, and reacted for 3.25 hours at reflux temperature. After dilution with ethyl acetate, a solution of acrylic resin (A-6) (weight average molecular weight 1.4 million, dispersion degree 4.2, glass transition temperature -33°C, solid content concentration 22.6%, viscosity 8700 mPa·s (25°C), refractive index: 1.498 ) was obtained.

<Production of acrylic resin (A'-1)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 88 parts of butyl acrylate (a2), 10 parts of benzyl acrylate (a3), 2-hydroxyethyl acrylate (a1) ) 0.5 parts, acrylic acid (a1) 1.5 parts, ethyl acetate 47.2 parts, acetone 42 parts, and azobisisobutyronitrile (AIBN) 0.013 parts as a polymerization initiator are added, and AIBN and ethyl acetate are appropriately added while reaction is carried out at reflux temperature for 3.25 hours. After dilution with ethyl acetate, acrylic resin (A'-1) solution (weight average molecular weight 1.4 million, dispersion degree, 3.5, glass transition temperature -49 ° C, solid content concentration 19.8%, viscosity 4780 mPa s (25 ° C), refractive index 1.476) was obtained.

[Preparation of acrylic resin (B)]

<Acrylic resin (B-1)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 93 parts of butyl acrylate (bA) (b2), 2 parts of methyl methacrylate (MMA) (b2), 2 parts of dimethyl 5 parts of acrylamide (DMAA) (b1), 43 parts of ethyl acetate, 42 parts of acetone, and 0.013 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator were added, and reacted at reflux temperature for 3.25 hours while appropriately adding AIBN and ethyl acetate. Then, diluted with ethyl acetate to a solution of an acrylic resin (B-1) (weight average molecular weight 1.1 million, dispersion degree 4.6, glass transition temperature -49°C, solid content concentration 22.1%, viscosity 3800 mPa·s (25°C), refractive index 1.469) got

<Acrylic resin (B-2)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 90.5 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 7.5 parts of dimethylacrylamide (b1) parts, ethyl acetate 43 parts, acetone 42 parts, azobis isobutyronitrile (AIBN) 0.013 parts as a polymerization initiator, AIBN and ethyl acetate are added as appropriate, and reacted for 3.25 hours at reflux temperature, diluted with ethyl acetate, and acrylic resin (B-2) A solution (weight average molecular weight 1.1 million, dispersion degree, 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-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 88 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 10 parts of dimethyl acrylamide (b1) parts, ethyl acetate 43 parts, acetone 42 parts, azobisisobutyronitrile (AIBN) 0.013 parts as a polymerization initiator, AIBN and ethyl acetate are added as appropriate, and reacted for 3.25 hours at reflux temperature, diluted with ethyl acetate, and acrylic resin (B-3) A solution (weight average molecular weight 1.3 million, dispersion degree 4.0, glass transition temperature -44°C, solid content concentration 22.4%, viscosity 4800 mPa·s (25°C), refractive index 1.472) was obtained.

<Acrylic resin (B-4)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 83 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 15 parts of dimethylacrylamide (b1) parts, 43 parts of ethyl acetate, 42 parts of acetone, 0.013 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator, add AIBN and ethyl acetate appropriately, and react for 3.25 hours at reflux temperature, then dilute with ethyl acetate and dilute with acrylic resin (B-4) solution (weight average molecular weight 1.3 million, dispersion degree 4.3, glass transition temperature -38 degreeC, solid content concentration 23.4%, viscosity 7900 mPa*s (25 degreeC), refractive index 1.475) was obtained.

<Acrylic resin (B-5)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 78 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 20 parts of dimethyl acrylamide (b1) parts, 43 parts of ethyl acetate, 42 parts of acetone, 0.013 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator, add AIBN and ethyl acetate appropriately, and react for 3.25 hours at reflux temperature, then dilute with ethyl acetate and dilute with acrylic resin (B-5) A solution (weight average molecular weight 1.4 million, dispersion degree 3.6, glass transition temperature -33°C, solid content concentration 22.2%, viscosity 4500 mPa·s (25°C), refractive index 1.478) was obtained.

<Acrylic resin (B-6)>

In a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 93 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 5 parts of dimethyl acrylamide (b1) parts, 22 parts of ethyl acetate, 42 parts of acetone, 0.013 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 3.25 hours of reaction at reflux temperature while appropriately adding AIBN and ethyl acetate, and then diluted with ethyl acetate to dilute with acrylic resin (B-6) A solution (weight average molecular weight 1.3 million, dispersion degree 2.9, glass transition temperature -49°C, solid content concentration 22.7%, viscosity 8200 mPa·s (25°C), refractive index 1.469) was obtained.

<Acrylic resin (B'-1)>

Into a four-mouth round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer, 98 parts of butyl acrylate (b2), 2 parts of methyl methacrylate (b2), 43 parts of ethyl acetate, 42 parts of acetone Add 0.013 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator, react for 3.25 hours at reflux temperature while appropriately adding AIBN and ethyl acetate, and then dilute with ethyl acetate to obtain an acrylic resin (B'-1) solution (weight An average molecular weight of 1 million, a dispersion degree of 2.9, a glass transition temperature of -54°C, a solid content concentration of 22.0%, a viscosity of 4300 mPa·s (25°C), and a refractive index of 1.466) were obtained.

[Examples 1 to 16, Comparative Examples 1 to 9]

＜Compatibility (Transparency)＞

According to the combination described in Table 3, the acrylic resin (A) and the acrylic resin (B) are blended so that the weight ratio (solid content) is 1:1, and the light-peelable PET (manufactured by Toray Co., Ltd., "Toray Lumirer SP01": Coated to a thickness of 38 µm After drying at 100°C for 3 minutes, attach to alkali-free glass (Corning Corporation, "Eagle XG": thickness 1.1 mm), remove the separator and haze Compatibility (transparency) was evaluated by measuring haze (%) using the meter "HAZE MATER NDH2000" (manufactured by Nippon Denshoku Kogyo Co., Ltd.).In addition, this mechanism is based on JIS K 7361-1. is as follows: Table 3 shows the results.

(evaluation)

○...haze less than 1%

x... haze is 1% or more

[Crosslinking agent (C)]

The following were prepared as a crosslinking agent (C).

-(C-1): 55% ethyl acetate solution of tolylene diisocyanate adduct of trimethylolpropane ("Colonate L-55E" manufactured by Nippon Polyurethane)

-(C-2) 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane ("TETRAD C" manufactured by Mitsubishi Gas Chemicals)

[Silane coupling agent (D)]

As the silane compound (D), the following were prepared.

· (D-1): oligomeric 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)]

As the antistatic agent (E), the following were prepared.

·(E-1): Lithium bistrifluoromethanesulfonylimide (tetraethylene glycol dimethyl ether dispersion) (“Sankonol TGR” manufactured by Sanko Chemical)

-(E-2): tri-n-butylmethylammonium bistrifluoromethanesulfonimide ("FC-4400" manufactured by 3M Corporation)

[Examples 17-30, Comparative Examples 10-15]

By blending each blending component prepared and prepared as described above in the ratio shown in Table 4 below, a pressure-sensitive adhesive composition serving as a pressure-sensitive adhesive forming material is prepared, and this is diluted with ethyl acetate (viscosity [500 to 10000 mPa·s (25° C.) )]), an adhesive composition solution was prepared.

Next, the pressure-sensitive adhesive composition solution of Examples 17 to 30 and Comparative Examples 10 to 15 is applied to a polyester release sheet so that the thickness after drying is 25 μm, dried at 100° C. for 3 minutes, and then the formed pressure-sensitive adhesive composition layer is applied to a polarizing plate It transcribed to (protective film: TAC film by a Fujifilm company), it was made to age on 23 degreeC and the conditions of 65 %RH for 7 days, and the adhesive layer lamination|stacking polarizing plate was obtained.

In addition, the said polarizing plate was cut and used so that it might become 0 degree|times with respect to a stretch axis|shaft.

Using the pressure-sensitive adhesive layer laminated polarizing plate obtained in this way, the gel fraction, durability (moisture and heat resistance test, heat resistance test, heat cycle test), light leakage resistance, adhesive force/rework property, holding power, antistatic performance, and transparency are shown below. Each method was measured and evaluated. These results are shown together in Table 4 below.

[Gel fraction]

The release sheet of the obtained pressure-sensitive adhesive layered polarizing plate was peeled off, the pressure-sensitive adhesive layer was scraped off by 0.1 g, the pressure-sensitive adhesive layer was wrapped with a 200 mesh SUS wire mesh and immersed in ethyl acetate at 23° C. for 24 hours, and the insoluble pressure-sensitive adhesive remaining in the wire mesh The weight percentages of the components were determined.

[Durability, light leakage resistance]

The release sheet of the obtained pressure-sensitive adhesive layer polarizing plate was peeled off, the pressure-sensitive adhesive layer side was pressed against an alkali-free glass plate (Eagle XG, manufactured by Corning), and the polarizing plate and the glass plate were attached, followed by autoclave treatment (50° C., 0.5 MPa, 20 min), and then foaming and peeling were evaluated in durability tests (moist and heat resistance test, heat resistance test, heat cycle test) as follows.

In addition, in the heat resistance test, in addition to the evaluation of foaming, etc., a sample for light leakage observation was prepared in which the same sample was attached to both sides of the table and the back so that the polarizing plate became cross nicol (extension axis is 0-90°), and the following The same light leakage resistance was evaluated. In addition, the used test piece size was used by piercing|piercing by 20 cm x 15 cm. However, for the light leakage test of Example 30, it was used by piercing 31 cm x 17.4 cm.

〔durability〕

(1) Moist heat resistance test

In the endurance test of 60 degreeC, 90%RH, and 168 hours, it evaluated as follows.

(2) Heat resistance test

In the endurance test of 80 degreeC and 168 hours, it evaluated as follows.

(3) Heat cycle test

After leaving at -30 DEG C for 30 minutes, the operation of leaving at 80 DEG C for 30 minutes was evaluated as follows in a durability test in which 168 cycles (168 hours) were performed as one cycle.

(Evaluation standard)

The presence or absence of defects (foaming, streaking, floating, peeling) for each of the above (1) to (3) was evaluated.

◎・・・No flaws

○・・Defects within 0.5 mm from the end of the polarizing plate

×... flaws inside more than 0.5 mm from the end of the polarizing plate

[Light leakage resistance]

In the endurance test of 80 degreeC and 150 hours, light leakage resistance was measured and evaluated as follows. In addition, about Example 30, it measured and evaluated by the endurance test of 50 degreeC, 90 %RH, and 150 hours.

(measuring device)

・"EyeScale" (manufactured by Eye Systems, Inc.)

(Measuring conditions)

・Camera lens aperture No. 16

・Camera GAIN10

・Shutter speed 1/1000

·Luminance 9000

Place the sample for light leakage observation on the backlight set to

・Camera lens aperture No. 4

・Camera GAIN6

・Shutter speed 1/30

Photographing was performed under the conditions of

The evaluation criteria are as follows.

(Evaluation standard)

◎···No light leakage.

○··Slight light leakage

×···Clear light leakage

In Comparative Examples 11 to 15, since peeling of the polarizing plate occurred, light leakage could not be evaluated.

[Adhesiveness, reworkability]

After cut|disconnecting the obtained polarizing plate with a pressure-sensitive adhesive layer to a width of 25 mm, it was attached to an alkali-free glass (Eagle XG manufactured by Corning Corporation), and autoclaved (50°C, 0.5 MPa, 20 minutes) was performed, 23°C, 50% RH atmosphere After leaving still for 24 hours under a 180 degree peel test, adhesive force was measured, and rework property was evaluated as follows.

(Evaluation standard)

◎···10N or less

○···> Greater than 10N and less than 15N

×···15N or more

〔retention〕

The polarizing plate with an adhesive layer is cut to be 25 mm x 25 mm, the release sheet is peeled, the adhesive layer side is attached to a polished SUS plate, a load of 1 kg is applied under the conditions of 80 ° C. According to the measurement method of JIS Z 0237, discrepancy was assessed. The evaluation criteria are as follows.

(Evaluation standard)

◎···No shift after 1440 minutes (N.C)

○··· After 1440 minutes, a deviation of less than 10 mm

×··· After 1440 minutes, a deviation of 10 mm or more

[antistatic properties]

After leaving the pressure-sensitive adhesive layer polarizing plate at 23° C. and 50%RH atmosphere for 24 hours, a surface resistivity measuring device (manufactured by Mitsubishi Chemical Analytech Co., Ltd., device name “Hiresta-UPMCP-HT450”) was measured except for the separator of the pressure-sensitive adhesive layer. The surface resistivity of the adhesive layer was measured using it. The evaluation criteria are as follows.

(Evaluation standard)

◎...less than 1.0E+11Ω/cm2

○...1.0E+11Ω/cm2 or more, 1.0E+12Ω/cm2 or more

×··1.0E+12Ω/cm2 or more

[Transparency]

The pressure-sensitive adhesive composition solutions of Examples 17 to 30 and Comparative Examples 10 to 15 were applied to a polyester-based light-peelable release sheet so that the thickness after drying was 25 μm, dried at 100° C. for 3 minutes, and then poly An ester-based heavy release release sheet was attached, and it was aged for 7 days under the conditions of 23°C and 65% RH to obtain a sheet with an adhesive layer. The light release release sheet of the obtained sheet was removed, and the heavy release sheet attached to the alkali-free glass (Eagle XG manufactured by Corning Corporation) was removed, and the haze (%) was used using a haze meter "HAZE MATER NDH2000" (manufactured by Nippon Denshoku Kogyo Co., Ltd.). ) to evaluate transparency.

In addition, this mechanism is based on JISK7361-1. The evaluation criteria are as follows.

(evaluation)

○...haze less than 1%

x... haze is 1% or more

From the evaluation results in Table 4, the pressure-sensitive adhesives having the composition of Examples 17 to 30 have excellent compatibility with acrylic resins, so they have high transparency, and excellent durability (especially resistance to resistance) when pasting a polarizing plate and a glass substrate. heat cycle performance), light leakage resistance, rework property, and antistatic property.

On the other hand, from Table 3, with respect to the acrylic resin (A), in Comparative Examples 1 to 4, in which the polymerization component is blended with the acrylic resin (B'-1) which does not contain the non-reactive polar functional group-containing monomer (b1), the acrylic resin It can be seen that the compatibility between them is inferior.

Further, from Tables 3 and 4, in Comparative Examples 5 to 8, 10 and 11 in which the acrylic resin (A'-1) and the acrylic resin (B) having a small content of the reactive functional group-containing monomer (a1) in the polymerization component were blended, Although it is excellent in compatibility between acrylic resins, it turns out that durability is inferior.

Further, from Tables 3 and 4, the acrylic resin (A'-1) having a small content of the reactive functional group-containing monomer (a1) in the polymerization component and the acrylic resin in which the polymerization component does not contain the non-reactive polar functional group-containing monomer (b1) In Comparative Examples 9 and 12 to 15 in which (B'-1) was blended, it was found that although the compatibility between the acrylic resins was excellent, the durability performance and light leakage resistance were inferior.

Although this invention was detailed also demonstrated with reference to specific embodiment, it is clear for those skilled in the art that various changes and correction can be added without departing from the mind and range of this invention. This application is based on the JP Patent application (Japanese Patent Application No. 2014-147865) for which it applied on July 18, 2014, The content is taken in here as a reference.

The pressure-sensitive adhesive composition of the present invention is an adhesive exhibiting excellent durability (especially heat cycle resistance) when pasting a polarizing plate and a glass substrate, etc., and also light leakage resistance, rework resistance, antistatic property, transparency (compatibility) Since it can form an excellent adhesive, it is very useful as an adhesive for obtaining the adhesive layer lamination|stacking optical member obtained by using as an adhesive for optical members, especially an adhesive layer polarizing plate, and an image display apparatus.

Claims (11)

A pressure-sensitive adhesive composition containing an acrylic resin (A) formed by polymerizing a polymerization component containing a reactive functional group-containing monomer (a1), and an acrylic resin (B) formed by polymerization of a polymerization component not containing a reactive functional group-containing monomer,
The polymerization component of the acrylic resin (A) contains 2.5 to 30% by weight of the reactive functional group-containing monomer (a1), the weight average molecular weight of the acrylic resin (A) is 1 million or more, and the polymerization component of the acrylic resin (B) This includes the non-reactive polar functional group-containing monomer (b1), the non-reactive polar functional group-containing monomer (b1) is an amide group-containing monomer, and the content ratio of the acrylic resin (A) to the acrylic resin (B) [(A): (B)] (weight ratio) is (A):(B)=100:50-100:500, The adhesive composition characterized by the above-mentioned. The method according to claim 1,
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. The method according to claim 1 or 2,
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. delete delete The method according to claim 1 or 2,
The weight average molecular weight of an acrylic resin (B) is 1 million or more, The adhesive composition characterized by the above-mentioned. delete The method according to claim 1 or 2,
A crosslinking agent (C) is contained, The adhesive composition characterized by the above-mentioned. 9. The method of claim 8,
The cross-linking agent (C) is at least one selected from the group consisting of an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent. The pressure-sensitive adhesive composition according to claim 1 or 2 is crosslinked by a crosslinking agent (C), characterized in that the pressure-sensitive adhesive. A pressure-sensitive adhesive for a polarizing plate comprising the pressure-sensitive adhesive according to claim 10.