KR20100075726A - Adhesive composition and optical member using the same - Google Patents

Abstract

PURPOSE: An adhesive composition and an optical member using thereof are provided to secure the re-working property and the durability under the high humidity condition, and to apply the composition for adhering a thin layer adherent. CONSTITUTION: An adhesive composition contains a (meth)acrylic polymer, and a hardener including a functional group reacting to a cross-linking functional group. The gel fraction of the composition is 55~80%. The (meth)acrylic polymer is formed by polymerizing the following: 94~98.9 parts of (meth)acrylate monomer by weight; 1~5 parts of macro monomer by weight, and 0.1~1 parts of (meth)acrylic polymer by weight including at least one cross-linking functional group selected from the group consisting of a carboxyl group, an amino group, an amide group, a hydroxyl group, and an acetacetoxy group.

Description

Adhesive composition and optical member using the same TECHNICAL FIELD

The present invention relates to an adhesive composition and an optical member using the same. More specifically, the present invention relates to an adhesive composition and an optical member excellent in rework resistance, light leakage resistance and durability.

In recent years, the use of flat panel displays (FPD), such as liquid crystal display (LCD), plasma display (PDP), and organic EL device, has been expanding. In these display devices, the method of adhering various optical members, such as a polarizing plate, a retardation plate, and an antireflection film, to a base material with an adhesive is used.

These display devices are mounted on various portable devices, and miniaturization, ultra-thin, and light weight of portable devices are progressing. The pressure-sensitive adhesives that can be used for such display devices are required to maintain adhesion even in harsh environments and long-term use. It is becoming. In particular, in a high temperature and high humidity environment, there exists a problem that defects, such as foaming and peeling, arise between an adhesive and a board | substrate, and the adhesive which has the outstanding durability also in high temperature and high humidity conditions is calculated | required.

On the other hand, when defects, such as a foreign material mixing and position shift, occur at the time of adhesion | attachment of an optical member, it is necessary to peel an optical member from a base material and to adhere again. When peeling an optical member from a base material, the rework property (repeelability) which can peel easily an optical member from a board | substrate is required, without damaging the gap change of a liquid crystal cell, destruction of a board | substrate, or the like. Moreover, when an adhesive is used for LCD, the characteristic (light leakage resistance) as having prevented light leakage by shrinkage | contraction of a polarizing plate has also been calculated | required.

As a method for improving the durability and reworkability of the pressure-sensitive adhesive, Patent Literature 1 discloses 0.2 to 3 parts by weight of a (meth) acryloyl group-containing macromonomer having a number average molecular weight of 2000 to 20000 while having a glass transition temperature of 40 ° C or higher, Copolymer of 57-98.8 weight part of alkyl (meth) acrylates, 1-20 weight part of functional group containing monomers, and 0-20 weight part of other monomers copolymerizable with the said alkyl (meth) acrylate at least (weight average molecular weight 50 1 to 2 million) is disclosed.

In addition, Patent Document 2 has a functional group reacting with an epoxy group with an acrylic copolymer (A) consisting of a (meth) acryloyl group-containing macromonomer having an average molecular weight of 2000 to 20000 and an acrylate monomer, even though the glass transition temperature is 40 ° C or higher. An adhesive composition comprising a silane compound (B) having a compound is disclosed.

[Patent Document 1] Japanese Unexamined Patent Publication No. Hei 8-209095

[Patent Document 2] Japanese Unexamined Patent Publication No. 10-140122.

However, although the adhesiveness of patent document 1 improves durability in high temperature, high humidity conditions, adhesive force is still strong and a glass plate may be damaged when it sticks to a thin glass plate etc. and peels (reworks). Moreover, also in the adhesive composition of patent document 2, since it has favorable adhesiveness with respect to a micro uneven surface, adhesive force is strong and rework characteristic is inadequate. Moreover, in the adhesive agent of patent document 1, and the adhesive composition of patent document 2, there existed a problem that light leakage leakage resistance was bad.

This invention is made | formed in view of the said situation, The objective is to provide the adhesive composition excellent in rework resistance, light leakage resistance, and durability, especially durability under high temperature and high humidity conditions.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, the present inventors discovered that the adhesive composition containing the polymer and hardening | curing agent which have a predetermined | prescribed composition and gel fraction expresses excellent rework property, durability, and light leakage resistance, The present invention has been completed.

That is, the subject of this invention is more than 94 mass parts of (A1) (meth) acrylate type monomers 98.9 mass parts or less, (A2) macromonomer 1 mass part or more and 5 mass parts or less, and (A3) carboxyl group, amino group, and amide (Meth) acrylic polymers formed by polymerizing 0.1 part by mass or more and less than 1 part by mass of a (meth) acrylate monomer containing at least one crosslinkable functional group selected from the group consisting of a group, a hydroxyl group and an acetacetoxy group ( A) [the total amount of (A1), (A2) and (A3) is 100 parts by mass]; And

A curing agent (B) having a functional group reacting with the crosslinkable functional group,

It is achieved by the adhesive composition that a gel fraction is 55% or more and 80% or less.

The pressure-sensitive adhesive composition of the present invention is excellent in rework resistance, light leakage resistance and durability, particularly under high temperature and high humidity conditions. Therefore, the adhesive composition of this invention is effective for adhesion | attachment of thin layer adherends, such as various plastic films, and especially when used for a polarizing plate, the outstanding rework property, light leakage resistance, and durability can be obtained.

Hereinafter, embodiments of the present invention will be described.

This invention is more than 94 mass parts of (A1) (meth) acrylate type monomers 98.9 mass parts or less, (A2) macromonomer 1 mass part or more and 5 mass parts or less, and (A3) carboxyl group, an amino group, an amide group, and a hydroxide A (meth) acrylic polymer (A) obtained by polymerizing 0.1 part by mass or more and less than 1 part by mass of a (meth) acrylate monomer containing at least one crosslinkable functional group selected from the group consisting of a period and an acetacetoxy group [ The total amount of (A1), (A2) and (A3) is 100 parts by mass]; And a curing agent (B) having a functional group reacting with the crosslinkable functional group, wherein the gel fraction is 55% or more and 80% or less.

Hereinafter, each component of the adhesive composition of this invention is demonstrated in detail. In addition, in this specification, "(meth) acrylate" is a generic term of acrylate and methacrylate. Similarly, the compound containing (meth), such as (meth) acrylic acid, is also a general term for the compound which has "meta" in a name, and the compound which does not have "meta".

(A) ( Meta Acrylic Polymer

(Meth) acrylic-type polymer (A) (henceforth only called a "component (A)") used by this invention is a (A1) (meth) acrylate type monomer, (A2) macromonomer, and (A3) crosslinkability It is made by copolymerizing a functional group containing (meth) acrylate type monomer.

(A1) ( Meta ) Acrylate Monomer

A (meth) acrylate type monomer (henceforth only called "component (A1)") is an ester of (meth) acrylic acid which does not have a crosslinkable functional group in a molecule | numerator. As a specific example of a component (A1), for example, methyl (meth) acrylate,

Ethyl (meth) acrylate, propyl (meth) acrylate,

Isopropyl (meth) acrylate, n-butyl (meth) acrylate,

Isobutyl (meth) acrylate, tert-butyl (meth) acrylate,

Isoamyl (meth) acrylate, n-hexyl (meth) acrylate,

n-heptyl (meth) acrylate, n-octyl (meth) acrylate,

tert-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,

Decyl (meth) acrylate, isodecyl (meth) acrylate,

Tridecyl (meth) acrylate, stearyl (meth) acrylate,

Isostearyl (meth) acrylate, phenyl (meth) acrylate,

Benzyl (meth) acrylate, dodecyl (meth) acrylate,

Tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate,

4-n-butylcyclohexyl (meth) acrylate,

2-ethylhexyl diglycol (meth) acrylate, butoxyethyl (meth) acrylate,

Butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate,

2- (2-methoxyethoxy) ethyl (meth) acrylate,

2- (2-butoxyethoxy) ethyl (meth) acrylate,

4-butylphenyl (meth) acrylate, phenyl (meth) acrylate,

2,4,5-tetramethylphenyl (meth) acrylate, phenoxymethyl (meth) acrylate,

Phenoxyethyl (meth) acrylate,

Polyethylene oxide monoalkyl ether (meth) acrylate,

Polyethylene oxide monoalkyl ether (meth) acrylate,

Polypropylene oxide monoalkyl ether (meth) acrylate,

Trifluoroethyl (meth) acrylate,

Pentadecafluorooxyethyl (meth) acrylate, 2-chloroethyl (meth) acrylate,

2, 3- dibromopropyl (meth) acrylate, tribromophenyl (meth) acrylate, etc. are mentioned. These components (A1) may be used independently or may be used in combination of 2 or more type.

Among these components (A1), methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate and tert-butyl (meth) acrylate are preferable. , Methyl acrylate, ethyl acrylate, n-butyl acrylate are more preferred, and methyl acrylate, n-butyl acrylate are particularly preferred.

The usage-amount of a component (A1) makes the total amount of a component (A1)-(A3) 100 mass parts, It is more than 94 mass parts and 98.9 mass parts, It is preferable that they are 95.2 mass parts or more and 98.5 mass parts or less, 96.3 mass parts or more It is more preferable that it is 97.7 mass parts or less. If it exists in such a range, favorable adhesiveness and heat resistance will be shown.

(A2) Macromonomer

Macromonomer is a high molecular weight monomer having a polymerizable functional group (polymerizable group), and is composed of a polymer chain portion and a polymerizable group portion.

The polymerizable group of the macromonomer reacts with the (A1) (meth) acrylate monomer or the (A3) crosslinkable functional group-containing (meth) acrylic monomer to form a main chain structure in the (meth) acrylic polymer (A), The polymer chain portion of the macromonomer forms a side chain grafted to the main chain of the (meth) acrylic polymer (A). This side chain forms a microdomain (discontinuous phase) in the adhesive composition of this invention, and acts as a high aggregation component. For this reason, the pressure-sensitive adhesive composition of the present invention has good cohesive force even in a structure having a small crosslinking density by a crosslinking agent or the like, and is excellent in stress relaxation property after low-speed deformation, thus improving light leakage resistance, rework resistance and durability.

As the polymerizable group, a group having an ethylenically unsaturated double bond (ethylenically unsaturated group) is preferable. Specifically, at least one selected from the group consisting of vinyl group, allyl group, (meth) acryloyl group, propenyl group, vinylidene group, and vinylene group is preferable, and (meth) acryloyl group is more preferable among them. . It is preferable that a polymerizable group exists at the terminal of a macromonomer, and it is more preferable from a viewpoint of the stability at the time of superposition | polymerization that it exists only at one terminal of a macromonomer. However, the polymerizable group may exist as the side chain of the macromonomer, or may exist at both ends of the chain of the macromonomer.

The polymer chain | strand part which comprises a macromonomer is methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate It is preferable that it is a (co) polymer which has a repeating unit derived from styrene, acrylonitrile, etc. as a main structural unit. These polymer chain parts may be comprised by a single repeating unit, or may be comprised by a plurality of repeating units. In addition, when a polymer chain is a copolymer which consists of a some repeating unit, the repeating form is not restrict | limited, Any of an alternating copolymer, a random copolymer, and a block copolymer may be sufficient.

As a preferable example of the said macromonomer, the monomer represented by following formula (I) is mentioned, for example:

[Formula I]

However, in the formula (I), R ¹ represents a hydrogen atom or a methyl group. X represents a single bond or a divalent bond group. Y is methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, styrene, and acrylonitrile A polymer chain formed by homopolymerizing or copolymerizing one or two or more monomers selected from reels is shown. Especially, the polymer chain formed by copolymerizing methyl methacrylate and styrene alone, the polymer chain formed by copolymerizing acrylonitrile and styrene, is preferably used.

As said bivalent coupling group, a linear, branched or cyclic alkylene group, aralkyl group, arylene group, etc. are mentioned, for example. These may further have substituents, such as a hydroxyl group and a cyano group. As carbon number of the said alkylene group, 1-10 are preferable and 1-4 are more preferable. As said alkylene group, a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, a decylene group, etc. are mentioned, for example. Among these, methylene group, ethylene group, propylene group, etc. are preferable. As carbon number of the said aralkylene group, 7-13 are preferable. As said aralkylene group, a benzylidene group, a cinnamilide group, etc. are mentioned, for example. As carbon number of the said arylene group, 6-12 are preferable. As said arylene group, a phenylene group, cumenylene group, mesitylene group, tolylene group, xylene group, etc. are mentioned, for example. Among these, a phenylene group is preferable.

Among the divalent bonding groups, -NR ^2- , -COO-, -0CO-, -O-, -S-, -SO ₂ NH-, -NHSO _2- , -NHCOO-, -OCONH-, or double Groups derived from the summons and the like may be interposed as a bonding group. R <^2> is hydrogen or alkyl groups, such as a methyl group, an ethyl group, and a propyl group.

It is preferable that the number average molecular weight (Mn) of a macromonomer exists in the range of 2000-20000, It is more preferable to exist in the range of 2000-10000, It is still more preferable to exist in the range of 4000-8000. When number average molecular weight (Mn) is 2000 or more, sufficient adhesive strength can be ensured and it is excellent in heat resistance. On the other hand, when it is 20000 or less, the fall of workability by the raise of the viscosity of an adhesive composition can be suppressed. The value of the number average molecular weight (Mn) can be controlled by appropriately selecting the amounts of the chain transfer agent and the polymerization initiator to be added to the polymerization system. In addition, in this invention, the polystyrene conversion value measured by the GPC (gel permeation chromatography) method shall employ | adopt the number average molecular weight (Mn) of a macromonomer.

It is preferable that the glass transition temperature (Tg) of a macromonomer is 40-150 degreeC, It is more preferable that it is 60-140 degreeC, It is still more preferable that it is 80-130 degreeC. Cohesion force (physical crosslinking effect) by the microdomain of the macromonomer is expressed in the temperature range below the glass transition temperature of the macromonomer, and such cohesion force is lowered in an environment near the glass transition temperature. Therefore, it is preferable that glass transition temperature (Tg) is 40 degreeC or more from the point which ensures sufficient cohesion force. On the other hand, if it is 150 degrees C or less, since the fall of stickiness and the adhesive force can be suppressed, it is preferable.

There is no restriction | limiting in particular in the method of manufacturing such a macromonomer, For example, (1) The polymer chain (living polymer anion) which comprises a macromonomer by living anion polymerization is manufactured, and methacrylic acid chloride etc. are made to act on this Way; (2) a method of polymerizing a radical polymerizable monomer such as methyl methacrylate in the presence of a chain transfer agent such as mercapto acetic acid to obtain an oligomer having a carboxyl group at its terminal, and then reacting it with glycidyl methacrylate or the like; (3) In the presence of an azo polymerization initiator containing a carboxyl group, a radical polymerizable monomer such as methyl methacrylate is polymerized to obtain an oligomer having a carboxyl group at its terminal, and then macromonomerized with glycidyl methacrylate. Arbitrary methods, such as the method of making it, can be used.

By preparing a macromonomer using the method as described above, as the divalent linking group represented by X in the above formula (I), for example, a group as shown below is introduced:

A commercial item can also be used as said macromonomer. For example, a macromonomer whose terminal is a methacryloyl group and a segment is methyl methacrylate (MMA) (Product name: 45% AA-6 (AA-6S), AA-6; Toagosei Co., Ltd.) Product), the macromonomer whose segment is styrene (product name: AS-6S, AS-6; product made by Toagosei Co., Ltd.), the macromonomer whose segment is the copolymer of styrene / acrylonitrile (product name: AN-6S; Toa Kosei Co., Ltd., the macromonomer whose segment is butyl acrylate (product name: AB-6; Toagosei Co., Ltd. product), etc. can be used.

Among these components (A2), a (co) polymer having a repeating unit derived from methyl methacrylate (MMA) as a main structural unit (product name: 45% AA-6 (AA-6S), AA-6; Toagosei ( NOTE) Products are particularly preferably used because of their good compatibility. In addition, these macromonomers may be used independently or may be used together 2 or more types.

The usage-amount of a component (A2) makes a total amount of components (A1)-(A3) 100 mass parts, and is 1 mass part or more and 5 mass parts or less, It is preferable that they are 1.3 mass parts or more and 4.0 mass parts or less, 2.0 mass parts or more It is more preferable that it is 3.0 mass parts or less. By setting it as such a range, it becomes possible to make the cohesiveness of a (meth) acrylic-type polymer into a preferable state. If it is less than 1 mass part, sufficient cohesion force will not be obtained and there exists a possibility that rework property may fall. On the other hand, when it exceeds 5 mass parts, there exists a possibility that cohesion force may become high too much, adhesive force may fall, stress relaxation property may fall, and light leakage resistance may fall.

(A3) Crosslinkable  Containing functional groups ( Meta Acrylic Monomer

A crosslinkable functional group containing (meth) acrylic-type monomer (henceforth only a "component (A3)") is an acryl-type monomer which has a crosslinkable functional group in a molecule | numerator. A crosslinking structure is introduce | transduced into a (meth) acrylic-type polymer (A) by reacting and couple | bonding with the hardening | curing agent (B) which a crosslinkable functional group of a component (A3) mentions later.

The crosslinkable functional group is at least one of a carboxyl group, an amino group, an amide group, a hydroxy group and an acet acetyl group, preferably at least one of a carboxyl group and a hydroxy group, and more preferably a hydroxy group.

As a specific example of the component (A3),

Carboxyl groups such as (meth) acrylic acid, 2-methacryloyloxysuccinic acid, 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid Having an acrylic monomer;

Monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoethylaminopropyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, Amino group-containing (meth) acrylic monomers such as diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate, and methacryloxyethyltrimethylammonium chloride (meth) acrylate;

(Meth) acrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N, N-methylene bis (meth) acrylamide Amide group containing (meth) acrylic-type monomers, such as an amide and 2-hydroxyethyl acrylamide;

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl ( Meta) acrylate, 4-hydroxybutyl (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, Neopentylglycol mono (meth) acrylate, trimethylolethane di (meth) acrylate, trimethylolpropane di (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate Hydroxyl group-containing (meth) acrylic monomers such as 4-hydroxycyclohexyl (meth) acrylate and cyclohexane dimethanol mono (meth) acrylate;

Acetacetoxy group containing (meth) acrylic-type monomers, such as 2-aceto acetoxy ethyl (meth) acrylate, etc. are mentioned. Moreover, you may use the compound etc. which are obtained by addition reaction of glycidyl-group containing compounds, such as alkylglycidyl ether, arylglycidyl ether, and glycidyl (meth) acrylate, and (meth) acrylic acid. These components (A3) may be used independently or may be used in combination of 2 or more type.

Among these components (A3), cyclohexane dimethanol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid, 2-hydroxy Ethyl acrylamide and 2-acetoacetoxyethyl (meth) acrylate are preferable, and cyclohexane dimethanol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxyethyl acrylamide More preferred is cyclohexane dimethanol mono (meth) acrylate.

The usage-amount of a component (A3) makes 100 mass parts of total amounts of components (A1)-(A3), and is 0.1 mass part or more and less than 1 mass part, Preferably they are 0.2 mass part or more and 0.8 mass part or less, More preferably, Is 0.3 mass part or more and 0.7 mass part or less. If it is less than 0.1 mass part, since the amount of crosslinking by the crosslinking reaction with the hardening | curing agent mentioned later is small, there exists a possibility that it may cause deterioration of the rework property by the fall of durability or the fall of cohesion force. On the other hand, when it is 1 mass part or more, there exists a possibility that stress relaxation property may fall by high crosslinking and light leakage resistance may fall.

As mentioned above, in the adhesive composition of this invention, since high cohesion force is expressed by the microdomain structure formed from the side chain derived from a macromonomer (A2), the usage-amount of a component (A3) is made into a small quantity compared with the past like the said range. Even low cost bridges have high cohesion. Therefore, the adhesive composition of this invention can exhibit the outstanding durability, rework property, and light leakage resistance.

The method for producing the (meth) acrylic polymer (A) is not particularly limited, and conventionally known methods such as solution polymerization, emulsion polymerization, suspension polymerization, reverse phase suspension polymerization, thin film polymerization and spray polymerization using a polymerization initiator are known. Can be used. As a polymerization control method, adiabatic polymerization method, temperature controlled polymerization method, isothermal polymerization method, etc. are mentioned. In addition to the method of initiating the polymerization by the polymerization initiator, a method of initiating the polymerization by irradiating radiation, electron beams, ultraviolet rays or the like may be employed. Among them, a solution polymerization method using a polymerization initiator is preferable because the molecular weight can be easily controlled and impurities can be reduced. For example, using a ethyl acetate, toluene, methyl ethyl ketone, etc. as a solvent, adding 0.01 mass part or more and 0.50 mass part or less of polymerization initiators with respect to 100 mass parts of total amounts of components (A1)-(A3). And it can obtain by making it react for 3 to 10 hours at reaction temperature of 60-90 degreeC under nitrogen atmosphere, for example. As said polymerization initiator, For example, Azo compounds, such as azobisisobutyronitrile, 2,2'- azobis (2-methylbutyronitrile), azobiscyano valeric acid; tert-butylperoxy pivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butylperoxide, cumene hydroperoxide, benzoyl peroxide, tert-butylhydride Organic peroxides such as loperoxide; Inorganic peroxides, such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate, are mentioned. These may be used independently or may use 2 or more types together.

It is preferable that weight average molecular weight (Mw) is 700,000-2 million, and, as for the (meth) acrylic-type polymer (A) obtained by copolymerizing the said component (A1)-(A3), it is more preferable that it is 900,000-1,600,000. If the weight average molecular weight is less than 700,000, heat resistance may be insufficient. On the other hand, when a weight average molecular weight exceeds 2 million, stickiness may be low and adhesiveness may fall. In addition, in this invention, the polystyrene conversion value measured by the method as described in an Example shall employ | adopt the weight average molecular weight of a (meth) acrylic-type polymer (A). In addition, there is no restriction | limiting in particular about the copolymerization form of a (meth) acrylic-type polymer (A), Any of a block and a random may be sufficient.

The said component (A) may be used independently, or may be used in combination of 2 or more type of polymer.

(B) curing agent

In addition to the said component (A), the adhesive composition of this invention is a hardening | curing agent (B) which has a functional group which reacts with the crosslinkable functional group of a crosslinkable functional group containing (meth) acrylate type monomer (A3) (hereinafter, only a "component (Also referred to as "(B)"). A hardening | curing agent (B) reacts and couple | bonds with the crosslinkable functional group derived from the component (A3) in the said (meth) acrylic-type polymer (A), and forms a crosslinked structure.

As such a hardening | curing agent (B), when the crosslinkable functional group in a crosslinkable functional group containing (meth) acrylate type monomer (A3) is a carboxyl group, an epoxy group containing compound and an isocyanate group containing compound can be used suitably, When the crosslinkable functional group is a hydroxyl group, an isocyanate group-containing compound, an amino group-containing compound, or a formyl group-containing compound can be suitably used. When the crosslinkable functional group is an amino group or an amide group, an epoxy group-containing compound is suitable. It is possible to use, and when the said crosslinkable functional group is an acetacetoxy group, an isocyanate group containing compound and an amino group containing compound can be used suitably. Specifically, an isocyanate hardener, an epoxy hardener, a melamine hardener, a urea hardener, a dialdehyde hardener, a metal chelate compound, a metal alkoxide, a metal salt, etc. are mentioned. Especially, the isocyanate type hardening | curing agent whose hardening | curing agent (B) is an isocyanate group containing compound, especially when the crosslinkable functional group in a crosslinkable functional group containing (meth) acrylate type monomer (A3) is a hydroxyl group or a carboxyl group. Phosphorus combination is preferred in terms of stickiness (initial adhesion) and heat resistance.

The isocyanate-based curing agent is not particularly limited. Specifically, for example, triallyl isocyanate, dimer acid diisocyanate, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate Cyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2 , 4'-MDI), 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylidene diisocyanate (TMXDI), toluidine diisocyanate ( Aromatic diisocyanates, such as TODI) and 1, 5- naphthalene diisocyanate (NDI); Aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornene diisocyanatomethyl (NBDI) Nates; Alicyclic diisocyanates such as transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI), H12-MDI (hydrogenated MDI) Anates; Carbodiimide-modified diisocyanates of the diisocyanates; Or these isocyanurate modified diisocyanates etc. may be used. Moreover, the adduct of the said isocyanate compound and polyol compounds, such as a trimethylol propane, the biuret body and the isocyanurate body of these isocyanate compounds can also be used suitably.

The said isocyanate type compound may be synthesize | combined, or a commercial item may be used. As a commercial item of an isocyanate-type hardening | curing agent, coronate L (trimethylol propane / tolylene diisocyanate trimer adduct), coronate HL (trimethylol propane / hexamethylene diamond), for example Isocyanate trimer adduct), coronate HX (isocyanurate of hexamethylene diisocyanate), coronate 2030, coronate 2031 (above, manufactured by Nippon Polyurethane Co., Ltd.), Take Nate® D-102, Takenate® D-110N, Takenate® D-200, Takenate D-202 (above, Mitsui Chemical Co., Ltd.) ), Duranate (trademark) 24A-100, Duranate (trademark) TPA-100, Duranate (trademark) TKA-100, Duranate (trademark) P301-75E, Duranate (trademark) E402-90T, Duranate ( Trademark) E405-80T, Duranate TSE-100, Duranate D-101, Durane Agent may be mentioned (R) D-201 (above, Asahi Kasei Chemical's Co., Ltd.) and the like.

Among these isocyanate-based curing agents, Coronate L, Coronate HL, Takenate® D110N, and Duranate® 24A-100 are preferred, and Coronate L and Takenate® D110N are more preferred. Preferred, and coronate L is particularly preferred.

In addition, a hardening | curing agent (B) may be used individually by 1 type, or may be used in combination of 2 or more type.

In this invention, it is preferable that the compounding quantity of a component (B) is 0.05 mass part or more and 5 mass parts or less with respect to 100 mass parts of component (A). Cohesion force and heat resistance can be improved by introduction of the crosslinking point which the crosslinkable functional group and hardening | curing agent (B) which originate in the component (A3) in a polymer (A) react that it is 0.05 mass part or more. On the other hand, if it is 5 mass parts or less, such a crosslinking point will not become excessive and the adhesive composition of this invention can have the outstanding rework property and flexibility. The said compounding quantity becomes like this. More preferably, it is 0.05 mass part or more and 1 mass part or less, More preferably, it is 0.05 mass part or more and 0.7 mass part or less.

(C) other ingredients

The adhesive composition of this invention may contain a silane coupling agent in addition to the said component (A) and (B). By using a silane coupling agent, reactivity can be improved and the mechanical strength and adhesive strength of hardened | cured material can be improved. Such a silane coupling agent is not specifically limited. Specifically, for example

Methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane,

n-propyltrimethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane,

n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane,

Phenyltrimethoxysilane, diphenyldimethoxysilane,

Cyclohexylmethyldimethoxysilane, vinyltrichlorosilane,

Vinyl trimethoxy silane, vinyl triethoxy silane,

Vinyl tris (β-methoxyethoxy) silane,

β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane,

γ-glycidoxypropyltrimethoxysilane,

γ-glycidoxypropyltriethoxysilane,

γ-methacryloxypropylmethyldimethoxysilane,

γ-methacryloxypropyltrimethoxysilane,

γ-methacryloxypropylmethyldiethoxysilane

γ-methacryloxypropyltriethoxysilane,

γ-acryloxypropyltrimethoxysilane,

N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane,

N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane,

N-β- (aminoethyl) -γ-aminopropyltriethoxysilane,

γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,

N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane,

γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane,

Bis- (3- [triethoxysilyl] propyl) tetrasulfide,

(gamma)-isocyanate propyl triethoxysilane etc. are mentioned. In addition, a silane coupling agent having a functional group such as an epoxy group (glycidoxy group), an amino group, a mercapto group, a (meth) acryloyl group, a silane coupling agent containing a functional group reactive with these functional groups, and other couples The compound which has a hydrolyzable silyl group obtained by making ring agent, polyisocyanate, etc. react with arbitrary functional groups at arbitrary ratios can also be used.

The said silane coupling agent may synthesize | combine, or may use a commercial item. As a commercial item of a silane coupling agent, for example, KBM-303, KBM-403, KBE-402, KBM-403, KBE-502, KBE-503, KBM-5103, KEM-573, KBM-802, KBM- 803, KBE-846, KBE-9007 (above, Shin-Etsu Chemical Co., Ltd. product) etc. are mentioned.

Among these silane coupling agents, KBM-303, KBM-403, KBE-402, KBM-403, KBM-5103, KBM-573, KBM-802, KBM-803, KBE-846, KBE-9007 are preferable. KBM-403 is more preferable. In addition, the said silane coupling agent may be used independently, or may be used in combination of 2 or more type.

In the present invention, the amount of the silane coupling agent used is not particularly limited. Specifically, the blending amount of the silane coupling agent is preferably 0.01 parts by mass or more and 5 parts by mass or less, more preferably 0.03 parts by mass or more, based on 100 parts by mass of the total amount of the components (A) to (C). 2 mass parts or less, More preferably, they are 0.05 mass part or more and 0.5 mass parts or less. If it exists in this range, the outstanding heat resistance and adhesiveness can be exhibited. When the compounding quantity of the said silane coupling agent is less than 0.01 mass part, glass adhesiveness may fall. On the other hand, when it exceeds 5 mass parts, heat resistance may fall.

In addition to the silane coupling agent or in place of the silane coupling agent, the pressure-sensitive adhesive composition of the present invention is a curing accelerator, ionic liquid, inorganic filler, softener, antioxidant, antioxidant, stabilizer, tackifying resin, modified resin. (Polyol resin, phenol resin, acrylic resin, polyester resin, polyolefin resin, epoxy resin, epoxidized polybutadiene resin, etc.), leveling agent, antifoaming agent, plasticizer, dye, pigment (colored pigment, extender pigment, etc.), treatment agent And additives such as sunscreens, fluorescent brighteners, dispersants, thermal stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, lubricants and solvents. As the ionic liquid, for example, phosphonium ions, pyridinium ions, pyrrolidinium ions, imidazolium ions, guanidinium ions, ammonium ions, isurouronium ions, thiuronium ions, piperidinium Cationic components such as ions, pyrazolium ions, sulfonium ions, and anionic components include halogen ions, nitrate ions, sulfate ions, phosphate ions, perchlorate ions, thiocyanate ions, thiosulfate ions, sulfite ions, and tetrafluoro The substance which has an anion component, such as a bororate ion, a hexafluoro phosphate ion, a formate ion, an oxalic acid ion, an acetate ion, a trifluoroacetic acid ion, an alkylsulfonic acid ion, is mentioned. As the antioxidant, for example, dibutyl hydroxytoluene (BHT), Irganox (registered trademark) 1010, Irganox (registered trademark) 1035FF, Irganox (registered trademark) 565 (all, Chiba Specialty Chemicals, Inc.) Products). As tackifying resin, rosin, such as rosin acid, polymerization rosin acid, and rosin acid ester, terpene resin, terpene phenol resin, aromatic hydrocarbon resin, aliphatic saturated hydrocarbon resin, petroleum resin, etc. are mentioned, for example. As a ultraviolet absorber, a benzophenone series ultraviolet absorber, a benzotriazole type ultraviolet absorber, a benzoate type ultraviolet absorber, a triazine type ultraviolet absorber, etc. are mentioned, for example. Although the usage-amount of an additive in the case of using the said additive is not restrict | limited, For example, it is 0.1 mass part or more and 20 mass parts or less with respect to 100 mass parts of total amounts of the said component (A) and (B).

The pressure-sensitive adhesive composition of the present invention may be uniformly mixed by mixing each component described above in a batch, sequentially mixing the respective components, or mixing any of a plurality of components and then mixing the remaining components. It can manufacture by stirring. More specifically, it can prepare by heating at a temperature of 30-40 degreeC as needed, for example, and stirring for 10 minutes-5 hours, until it becomes uniform with a stirrer or the like.

The gel fraction of the adhesive composition of this invention is 55% or more and 80% or less, Preferably they are 60% or more and 75% or less, More preferably, they are 65 mass% or more and 75% or less. When the gel fraction is less than 55%, the cohesive force of the pressure-sensitive adhesive composition may be insufficient, resulting in inferior reworkability and durability. When it exceeds 80%, the cohesion force of the pressure-sensitive adhesive increases, but the softness and adhesiveness may decrease, or the stress relaxation property may decrease, resulting in inferior light leakage. The gel fraction is in the above range by adjusting the composition ratio of the (meth) acrylate polymer (A), in particular the amount of the crosslinkable functional group (meth) acrylate monomer (A3), the amount of the curing agent (B), the curing accelerator, and the like. I can regulate it. In addition, in this invention, the gel fraction shall employ | adopt the value measured by the method as described in an Example.

The viscosity of the pressure-sensitive adhesive composition of the present invention is not particularly limited. However, in consideration of ease of coating and the like, the viscosity at 25 ° C. is preferably 0.5 to 8.0 Pa · s, more preferably 1.0 to 5.0 Pa · s. If the said viscosity is less than 0.5 Pa.s, a bump may arise in a coating surface. On the other hand, when it exceeds 8.0 Pa.s, coating streaks may occur.

It is preferable that the adhesive force with respect to glass of the adhesive composition of this invention is 2.0-8.0 N / 25 mm, It is more preferable that it is 3.0-7.0 N / 25 mm, It is still more preferable that it is 4.0-60 N / 25 mm. If it is 2.0 N / 25 mm or more, the adhesive force required for bonding of to-be-adhered bodies, such as a polarizing plate, is fully obtained. If it is 8.0 N / 25 mm or less, there will be little residue of a pool and it is excellent in rework property. In addition, in this invention, adhesive force shall employ | adopt the value measured by the method as described in an Example based on JISZ0237.

The adhesive composition of this invention can be used for the joining of various base materials. As a base material which can be used here, glass, a plastic film, paper, a metal foil, etc. are mentioned. As glass, general inorganic glass is mentioned. Examples of the plastic in the plastic film include polyvinyl chloride resin, polyvinylidene chloride, cellulose resin, acrylic resin, cycloolefin resin, amorphous polyolefin resin, polyethylene, polypropylene, polystyrene, ABS resin, Polyamide, polyester, polycarbonate, polyurethane, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and chlorinated polypropylene. The amorphous polyolefin resin usually has a polymerized unit of a cyclic polyolefin such as norbornene or a polycyclic norbornene monomer, and may be a copolymer of a cyclic olefin and a linear cyclic olefin. Examples of commercially available amorphous polyolefin resins include trade names ATON (ARTON) of JSR Corporation, ZEONEX (registered trademark) of Nihon Xeon Corporation, ZEONOR (registered trademark), APO of Mitsui Kagaku Co., Ltd., and Apel (registered trademark). . In order to form amorphous polyolefin resin into a film, well-known methods, such as a solvent casting method and a melt-extrusion method, are used suitably. Examples of the paper include imitation paper, fine paper, kraft paper, art coat paper, caster coated paper, pure white roll paper, parchment paper, water resistant paper, glassine paper, corrugated paper, and the like. As metal foil, aluminum foil etc. are mentioned, for example.

Therefore, this invention also provides the optical member provided with the adhesive layer formed from the adhesive composition of this invention.

As an optical member, a polarizing plate, a retardation plate, the optical film for plasma displays, the conductive film for touch panels, etc. are mentioned preferably, for example. Among these, the adhesive composition of this invention is excellent in the adhesiveness of a polarizing plate and glass. Of course, this invention is not limited to said form, It is also possible to use for adhesion | attachment of another member.

The adhesive composition of this invention may be used by directly apply | coating to one side or both surfaces of an optical film, and forming an adhesive layer, previously forming an adhesive layer on a peeling film, and transferring this to one side or both surfaces of an optical film. May be used.

Coating of the adhesive composition of this invention may be according to a conventionally well-known method, For example, a natural coater, a knife belt coater, a floating knife, a knife over roll, a knife on blanket, a spray, a dip, a kiss roll, a squeeze roll, reverse Various coating methods using apparatuses, such as a roll, an air blade, a curtain flow coater, a doctor blade, a wire bar, a die coater, a comma coater, a baker applicator, and a gravure coater, are mentioned. Moreover, what is necessary is just to select the coating thickness (thickness after drying) of the composition of this invention according to the base material to be used, and a use, Preferably it is 5-40 micrometers, More preferably, it is 15-30 micrometers.

The pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition of the present invention is obtained by crosslinking the above pressure-sensitive adhesive composition. In that case, although crosslinking of an adhesive composition is generally performed after application | coating of an adhesive composition, it is also possible to transfer the adhesive layer which consists of an adhesive composition after crosslinking to a base material etc .. Crosslinking of this adhesive composition is normally performed by standing still on conditions of 20-40 degreeC of temperature, 30-70% RH of relative humidity, and atmospheric pressure (atmospheric pressure).

The adhesive composition of this invention shows the outstanding flexibility, and thereby shows the outstanding rework property (repeelability) and workability. For example, in the bonding process of an optical member, even if the position shift of an optical film and a to-be-adhered body generate | occur | produces, an adhesive does not remain in a to-be-adhered body and can peel an optical film. In particular, when used for a polarizing plate, it is possible to obtain excellent light leakage resistance and rework resistance.

In addition, since the adhesive composition of this invention has the outstanding heat resistance, it can express the high durability which does not produce lifting and peeling by heat processing or high humidity treatment.

Example

The effect of this invention is demonstrated using the following example and a comparative example. However, the technical scope of the present invention is not limited only to the following examples.

In addition, the measurement of solid content and the viscosity of the solution in which the methacryl-type polymer (A) melt | dissolved was performed with the following method.

(Solid content)

Approximately 1 g of polymer solution is accurately weighed into an accurately weighed glass dish. After drying at 105 ° C for 1 hour, the temperature is returned to room temperature, and the total mass of the glass plate and the remaining solid content is accurately weighed. Solid content was computed by following formula (1), making Y as the total mass of the glass plate and polymer solution before drying the mass of a glass plate, and the polymer solution as Z, and making Z as the total mass of a glass plate and residual solid content.

(Viscosity)

The adhesive solution put into the glass bottle was temperature-controlled at 25 degreeC, and it measured by the Brookfield viscometer.

(Gel fraction)

About 0.1 g of the pressure-sensitive adhesive composition was weighed to obtain a weight W ₁ (g). This was collected in a sample bottle, and about 30 g of ethyl acetate was added and left to stand for 24 hours. After a predetermined time, the contents of the sample bottle were separated by filtration through a 200 mesh stainless steel wire mesh (weight of wire mesh W ₂ (g)), and the total weight W ₃ dried at 90 ° C for 1 hour ( g) was measured. At this time, the gel fraction was calculated by the following equation (2) from these measurements:

.

.

(Weight average molecular weight and number average molecular weight)

It measured by the measuring method and measurement conditions of the following Table 1.

Equipment: Gel Permeation Chromatography GPC (Instrument No. GPC-16) Detector: Differential Refractive Index Detector RI (8020 Type Sensitivity 32, manufactured by Tosso Corporation) UV detector UV (Waters 2424, wavelength 215nm, sensitivity 0.2AUFS Column: Tosso Corporation TSKgel GMHXL (two), G2500HXL (one)
(S / N M0052, M0051, N0010, φ7.8 mm x 30 cm) Solvent: Tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) Flow rate: 1.0ml / min Column temperature: 23 ℃ Sample: [Concentration] about 0.2%
10 g of the measurement solvent was added to 0.1 g of the polymer solution.
[Dissolution] The mixture was stirred gently at room temperature.
[Solubility] Soluble (visually confirmed)
Filtration It filtered on a 0.45 micrometer filter.
Injection volume: 0.200ml
Standard Sample: Monodisperse Polystyrene Data Processing: GPC Data Processing System

[ Example  One]

98.5 parts by mass of n-butyl acrylate (manufactured by Nihon Shokubai Co., Ltd.), 45% toluene of the macromonomer whose one end is a methacryloyl group and the segment is methyl methacrylate (MMA) in a container equipped with a reflux machine and a stirrer. Solution (Mn = 6000, brand name: AA-6S, product of Toago Seikagaku Kogyo Co., Ltd.) 1 mass part equivalent cyclohexane dimethanol monoacrylate "(CHDMAA) (product of Nihon Kasei Co., Ltd.) 0.5 Mass part and 130 mass parts of ethyl acetate were added. Subsequently, it heated up to 65 degreeC, performing nitrogen substitution, 0.075 mass part of azobisisobutyronitrile (AIBN) was added, and it superposed | polymerized for 6 hours, maintaining 65 degreeC. After completion of the polymerization reaction, 270 parts by mass of ethyl acetate was added to dilute to obtain a solution of methacryl polymer (A). Solid content of the obtained polymer solution was 19.0 mass%, and the viscosity was 5.0 Pa.s. In addition, the weight average molecular weight of the obtained methacryl-type polymer (A) was 1.3 million.

Next, coronate L (trimethylolpropane / tolylene diisocyanate) which is an isocyanate type hardening | curing agent which is a hardening | curing agent (B) with respect to 100 mass parts of methacryl-type polymers (A) to the polymer solution obtained above. 3-glycidoxypropylmethyldiethoxysilane (brand name: KBM403, Shin-Etsu Chemical Co., Ltd. product) which is 0.2 mass part of a nate trimer adduct and the product made by Nippon Polyurethane Co., Ltd., and a silane coupling agent. ) Were added so that it became 0.2 mass part, and it mixed at 25 degreeC for 15 minutes, and obtained the solution of the adhesive composition (1).

This solution was applied onto a peeling PET film (Mitsubishi Chemical Co., Ltd. product, MRF38, thickness: 38 micrometers) using the baker applicator, and it adhered to the polarizing plate so that the thickness after drying might be 25 micrometers. Thereafter, the mixture was aged at 23 ° C / 45% RH for 7 days to obtain a polarizing plate (1).

[ Example  2 and 3]

The pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the components (A1) to (A3), the curing agent (B), and the silane coupling agent of the acrylate polymer (A) were used in the composition as shown in Table 2 below. 2) and (3) were prepared.

Next, in Example 1, except having used the adhesive composition (2) and (3) produced above instead of the adhesive composition (1), it carried out similarly to Example 1, and it was polarizing plates 2 and (3). Got.

Thus, about the polarizing plates 2 and 3 obtained, heat resistance, moisture heat resistance, light leakage, and rework property were evaluated in accordance with the following method, respectively. The results are shown in Table 2 below.

[ Comparative example  1 and 2]

Comparative pressure-sensitive adhesive composition in the same manner as in Example 1 except that the acrylate-based polymer (A) components (A1) to (A3), a curing agent (B), and a silane coupling agent were used in a composition as shown in Table 2 below. (1) and (2) were prepared.

Next, in Example 1, instead of using the adhesive composition (1), except for using the comparative adhesive composition (1) and (2) produced above, respectively, it carried out similarly to Example 1, and the comparative polarizing plate (1) And (2).

Thus, about the comparative polarizing plates 1 and (2) obtained, the heat resistance, the heat-and-moisture resistance, the light leakage property, and the rework property were evaluated in accordance with the following method, respectively. The results are shown in Table 2 below.

[evaluation]

(Heat resistance test)

A sample cut to 120 mm (polarizing plate MD direction) x 60 mm from the polarizing plates produced in each of Examples and Comparative Examples was attached to a glass plate and subjected to autoclave treatment for 20 minutes under conditions of a temperature of 50 ° C. and a pressure of 5 kg / cm 2. It was done. Then, it was left to stand for 120 hours at the temperature of 80 degreeC, and the state of the sample after leaving to stand was observed. In addition, in the following Table 2, "good" means that peeling does not exist in a film edge part, and "peeling" means that there exists peeling in a film edge part.

(Humidity heat resistance test)

A sample cut to 120 mm (polarizing plate MD direction) x 60 mm from the polarizing plates produced in each of Examples and Comparative Examples was attached to a glass plate and subjected to autoclave treatment for 20 minutes under conditions of a temperature of 50 ° C. and a pressure of 5 kg / cm 2. It was done. Thereafter, the mixture was left to stand at a temperature of 60 ° C. and a humidity of 90% RH for 120 hours, and the state of the sample after standing was observed. In addition, in the following Table 2, "good" means that peeling does not exist in a film edge part, and "peeling" means that there exists peeling in a film edge part.

(Light leakage resistance test)

A sample cut in 120 mm (polarizing plate MD direction) x 60 mm and 120 mm (polarizing plate TD direction) x 60 mm from the polarizing plates produced by each Example and each comparative example was pasted so that each surface of a glass plate might overlap, and the temperature was 50 The autoclave process was performed for 20 minutes on condition of 5 degreeC and the pressure of 5 kg / cm <2>. Then, it was left to stand for 120 hours at the temperature of 80 degreeC, and the state of the sample after leaving to stand was observed. In addition, in Table 2 below, "good" means that light leakage hardly occurred, "bad" means that the edge part of a polarizing plate is whitening, and "inability to evaluate" means peeling of a glass plate and a polarizing plate. That means it could not be evaluated.

(Reworkability test)

The adhesive force was measured according to the JIS Z0237 adhesive tape and adhesive sheet test method. That is, the sample cut | disconnected by the 25 mm width from the polarizing plates produced by each Example and each comparative example was affixed on the glass plate, and autoclave process was performed for 20 minutes on condition of the temperature of 50 degreeC, and the pressure of 5 kg / cm <2>. Then, using the tensile tester, the adhesive force (N / 25mm) was measured by peeling angle 90 degrees and peeling rate 0.3m / min, and the peeling state was observed (measurement environment: 20 degreeC / 50%). RH). In addition, in the following Table 2, "af" shows interface breakage.

As can be seen from the above table, the optical members (Examples 1 to 3) using the pressure-sensitive adhesive compositions (1) to (3) of the present invention have a content of a crosslinkable functional group-containing (meth) acrylate monomer (A3). Compared with the optical member using the adhesive compositions of Comparative Examples 1 and 2 outside the scope of the present invention, it can be confirmed that the durability (heat resistance, heat and humidity resistance), light leakage resistance, and rework resistance are excellent.

Claims (5)

(A1) More than 94 mass parts of (meth) acrylate-based monomers 98.9 mass parts or less, (A2) 1 mass part or more and 5 mass parts or less of macromonomers, and (A3) carboxyl group, amino group, amide group, hydroxy group, and acetase (Meth) acrylic polymer (A) [wherein (A1), a polymerized polymerization of 0.1 part by mass or more and less than 1 part by mass of a (meth) acrylate monomer containing at least one crosslinkable functional group selected from the group consisting of oxy groups The total amount of (A2) and (A3) is 100 parts by mass]; And A curing agent (B) having a functional group reacting with the crosslinkable functional group, The pressure-sensitive adhesive composition having a gel fraction of 55% or more and 80% or less. The adhesive composition of Claim 1 whose adhesive force with respect to glass is 2.0-8.0 N / 25mm. The pressure-sensitive adhesive composition of claim 1, further comprising a silane coupling agent. The adhesive composition of Claim 1 whose compounding quantity of the said hardening | curing agent (B) is 0.05 mass part or more and 1 mass part or less with respect to 100 mass parts of said (meth) acrylic-type polymers (A). The optical member provided with the adhesive layer formed from the adhesive composition in any one of Claims 1-4.