KR101841768B1 - Pressure sensitive adhesive for optical use, pressure sensitive adhesive sheet for optical use and optical component having pressure sensitive adhesive layer - Google Patents

Abstract

The present invention has an antistatic property with a surface resistivity of about 5 x ¹⁰ < 10 ^> OMEGA / & squ /; or less, which is used when an optical member such as a polarizing plate is laminated on an adherend, and has good adhesion, re- And an antistatic agent for optical use which also has an antiseptic property (non-sticking property) of an antistatic agent.
(A) at least one of (A-1) an oxyalkylene group-containing (meth) acrylic monomer containing 5 to 90% (Meth) acrylate ester copolymer having (a-3) a (meth) acrylic acid alkyl ester as a constituent unit, (B) a (meth) acrylic acid ester copolymer having a reactive group- (C) an active energy ray curable compound, and (D) an antistatic agent, and the content ratio of the components (A) and (B) is in the range of 100: 1 to 100: And a pressure-sensitive adhesive for optical properties.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure sensitive adhesive for optical use, an optical adhesive sheet for optical use, and an optical member with a pressure-sensitive adhesive layer. BACKGROUND OF THE INVENTION < RTI ID =

The present invention relates to an optical pressure-sensitive adhesive, an optical pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer. More specifically, the present invention relates to an antireflection film which has antistatic properties, which is used when an optical member such as a polarizing plate is laminated on an adherend, has good adhesion, re-peelability (durability) and durability, To an optical member with a pressure-sensitive adhesive layer formed by providing a layer made of an optical pressure-sensitive adhesive sheet having a peeling film and an optical pressure-sensitive adhesive on an optical member such as a polarizing plate.

Optical members such as a polarizing plate, a retardation plate, an optical compensation film, a reflection sheet, and a brightness enhancement film used for a liquid crystal display or the like can be attached to a liquid crystal cell or the like through a pressure-sensitive adhesive layer.

In a liquid crystal cell, two transparent electrode substrates, on which an alignment layer is formed in general, are arranged so as to have a predetermined gap therebetween with its orientation layer inward, and the periphery thereof is sealed to insert the liquid crystal material into the gap And a polarizing plate is provided on the outer surface of the two transparent electrode substrates via a pressure-sensitive adhesive layer, respectively.

1 is a perspective view showing an example of the structure of the polarizing plate. As shown in this figure, the polarizing plate 10 generally has a three-layer structure in which triacetylcellulose (TAC) films 2 and 2 'are adhered on both sides of a polyvinyl alcohol polarizer 1 And a pressure sensitive adhesive layer 3 for sticking to an optical component such as a liquid crystal cell is formed on one side thereof and a release sheet 4 is attached to the pressure sensitive adhesive layer 3. On the surface of the polarizing plate opposite to the pressure-sensitive adhesive layer 3, a surface protective film 5 is usually provided.

When the polarizing plate is attached (or pasted) to the liquid crystal cell, the release sheet 4 is first peeled off, and the protective sheet 5 is attached to the liquid crystal cell via the exposed pressure- .

When the peeling sheet 4 or the surface protection film 5 is peeled off, these sheets, films and polarizing plates are made of a plastic material, so that the electrical insulation is high and static electricity is generated. If the static electricity generated at this time is stuck to the liquid crystal cell in a state where the static electricity remains, there is a fear that confusion may occur in the alignment of the liquid crystal molecules. The disarrangement of the alignment of the liquid crystal molecules thus formed may not be recovered. Even if the liquid crystal molecules are restored, the liquid crystal display manufacturing process does not proceed to the next process until recovery, The problem is pointed out. In addition, the presence of static electricity causes problems such as dust and garbage being sucked in.

In order to cope with such a problem, conventionally, countermeasures such as placing an antistatic agent on the substrate of the release sheet have been adopted. However, such a measure alone does not provide sufficient effect, and it is required to give the antistatic property to the pressure- have.

As a pressure-sensitive adhesive composition having an antistatic property, a pressure-sensitive adhesive composition in which an antistatic agent such as a surfactant is blended is known. As described above, when an antistatic agent such as a surfactant is added to the pressure-sensitive adhesive composition, antistatic properties are imparted, but compatibility between the surfactant and the pressure-sensitive adhesive polymer is poor. There has been a problem that the surfactant exudes under heat or wet heat conditions to contaminate the adherend or deteriorate the adhesive strength.

On the other hand, an antistatic pressure-sensitive adhesive containing an organic salt having a polyoxyalkylene structure as an antistatic agent has been disclosed for the purpose of improving the compatibility between the antistatic agent and the pressure-sensitive adhesive polymer (see, for example, Patent Document 1 ).

However, the above-mentioned organic salt having a polyoxyalkylene structure is not sufficient for compatibility with an acrylic polymer mainly used for adhesion of a polarizing plate, and therefore, by the heat resistance test, particularly the cooling / heating cycle test, And there was a fear of causing exfoliation. In addition, there has been a problem that odor may remain if an organic salt is used.

Further, in a pressure-sensitive adhesive composition containing a (meth) acryl-based polymer having a (meth) acrylic monomer having an alkyl group having 6 to 14 carbon atoms as a main component and a polyether polyol compound and an alkali metal salt, Is 1.0 or less and contains less than 0.1 part by weight of the alkali metal salt based on 100 parts by weight of the (meth) acryl-based polymer (see, for example, Patent Document 2).

However, this pressure-sensitive adhesive composition uses a combination of a polyether polyol compound and an alkali metal salt as a conductive agent, and can not sufficiently satisfy all of peeling electrification preventing property, adhesion property, durability and the like.

As an optical pressure-sensitive adhesive having an antistatic property, it is required to form a pressure-sensitive adhesive layer having a surface resistivity of 5 10 ¹⁰ ? /? Or less.

On the other hand, in a polarizing plate which is a member of a liquid crystal display, in particular, a polarizing plate integrated with a liquid crystal cell and a polarizing plate integrated with a viewing angle enlarging film, a polarizing plate and a retardation plate, a retardation plate and a retardation plate, (Hereinafter referred to as " resistance to light leakage ") caused by a change in stress caused by a dimensional change called shrinkage and expansion of the film (See, for example, Patent Document 3).

However, the surface resistivity of 5 × ¹⁰ 10 Ω / □ or less as good while Genie antistatic properties, good durability and light fastness optical pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer combines the leakage property is, it is not been found so far in fact that to be.

Examples of the prior art relating to the present invention include a pressure-sensitive adhesive composition (for example, see Patent Document 4) containing a (meth) acrylic polymer having an alkylene oxide group-containing reactive monomer as a monomer component and an alkali metal salt , And a lithium salt is contained in two kinds of polymers having different glass transition temperatures (see, for example, Patent Document 5).

Both of the pressure-sensitive adhesive compositions have a composition in which a hydrophilic monomer is frequently used as a monomer constituting the polymer in order to exhibit antistatic properties. Therefore, it is considered that the surface protective film which can be finally peeled off has sufficient performance in the pressure-sensitive adhesive layer formed by the above-described pressure-sensitive adhesive composition. However, when forming a part of the constitution of the liquid- And the light leakage property is expected to be a problem.

As a prior art document closest to the present invention, Patent Document 6 is proposed. In Patent Document 6, an acrylic copolymer obtained by copolymerizing a hydroxyl group-containing monomer, an acrylic copolymer copolymerized with acrylic acid, and a polyfunctional acrylate monomer And various antistatic agents are contained in the pressure-sensitive adhesive composition.

JP (Japan Special Feature) 2004-536940 A JP 2005-325255 A JP 3272921 B (JP H9-87593 A) JP 2007-92056 A JP 2008-248223 A JP 2008-32852 A

The pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition disclosed in Patent Document 6 has durability and light-leak resistance, and has a constant antistatic property. However, in the pressure-sensitive adhesive composition of the above document, the addition of various antistatic agents has been studied, but it has not been sufficient to exhibit excellent durability and light-resistance leak resistance, and further to exhibit excellent antistatic properties such as a surface resistivity of about 5 × 10 ¹⁰ Ω / have.

The present invention has been made under such circumstances and has an antistatic property with a surface resistivity of about 5 x ¹⁰ < 10 ^> OMEGA / & squ & or less which is used when an optical member such as a polarizing plate is laminated on an adherend, And an object of the present invention is to provide an optical pressure-sensitive adhesive having optical properties, heat resistance and light resistance, leak resistance and durability, and also an anti-seizing property (antistatic property) of an antistatic agent, an optical pressure-sensitive adhesive sheet having a release film using the same and an optical member with a pressure- .

The inventors of the present invention have made intensive studies to achieve the above object, and as a result, they have found that (A) a method for producing a polymer composition comprising (A) a polymerization reaction of a specific amount of a (meth) acrylic monomer containing an oxyalkylene group, (Meth) acrylate ester copolymer having (meth) acrylate ester as a structural unit, (B) a (meth) acrylic acid ester copolymer having a reactive group-containing (meth) acrylic monomer as a constituent unit, (C) It has been found that the object can be achieved by a pressure-sensitive adhesive comprising an antistatic agent and a pressure-sensitive adhesive which is obtained by crosslinking a pressure-sensitive adhesive forming material having a content of the components (A) and (B) in a specific range.

The present invention has been completed based on this finding.

That is,

(Meth) acrylate monomer having a reactive group (a-2), (a-2) a monomer having a reactive group (Meth) acrylic acid ester copolymer having a (meth) acrylic acid alkyl ester as a constituent unit, (B) a (meth) acrylic acid ester copolymer having a reactive (meth) acrylic monomer as a constituent unit, (C) (A) and the component (B) in a mass ratio of 100: 1 to 100: 50 is crosslinked. The pressure-sensitive adhesive composition according to any one of Optical adhesive,

[2] The optical pressure-sensitive adhesive according to the above item [1], wherein the content of the active energy ray-curable compound (C) is 1 to 50 parts by mass relative to 100 parts by mass of the total amount of the component (A)

[3] The resin composition according to the above [1] or [2], wherein the oxyalkylene group has 2 to 4 carbon atoms and the number of the oxyalkylene groups is 1 to 10 in the (a-1) oxyalkylene group- , The pressure-sensitive adhesive for optical use,

[4] The optical adhesive according to any one of [1] to [3], wherein the (a-2) reactive group-containing (meth) acrylic monomer is a hydroxyl group-

[5] The optical pressure-sensitive adhesive according to any one of the above items [1] to [4], wherein the reactive group-containing (meth) acrylic monomer as the structural unit of the component (B) is a carboxyl group-

[6] The positive resist composition as described in any of [1] to [5] above, wherein the content of the antistatic agent (D) is 0.1 to 10 parts by mass relative to 100 parts by mass of the total amount of the component (A), the component (B) Sensitive adhesive for optical use,

[7] The optical pressure-sensitive adhesive according to any one of [1] to [6], wherein the pressure-sensitive adhesive material further comprises (E)

[8] An optical pressure-sensitive adhesive sheet having a release film formed using the optical pressure-sensitive adhesive according to any one of [1] to [7]

[9] An optical member with a pressure-sensitive adhesive layer having a layer made of the optical pressure-sensitive adhesive according to any one of [1] to [7] above on an optical member,

[10] The optical member with a pressure-sensitive adhesive layer according to the above [9], wherein the optical member is a polarizer

.

Further, as a preferred embodiment of the present invention,

(a) an optical pressure-sensitive adhesive in which the active energy ray curable compound (C) is a polyfunctional (meth) acrylate-based monomer,

(b) an optical pressure-sensitive adhesive in which the antistatic agent (D) comprises an ionic compound in a solid form or a liquid form represented by the following general formula (1)

(Z ^{a +} ) _m · (A ^{b -} ) _n ... (One)

A, b, m and n are each an integer of 1 to 3, satisfying the relationship of a x m = b x n. In the formula, z ^{a +} represents a cation and A ^{b -} represents an anion. When Z ⁺ is in ^a plurality, the plurality of z ^{+ a} may be the same or different, A ^b-is is be the same or different], ^- if there is a plurality, the plurality of A ^b

(c) a pressure-sensitive adhesive for optical use further comprising a silane coupling agent,

(d) a pressure-sensitive adhesive for optical use wherein said crosslinking agent (E) is an isocyanate crosslinking agent,

(e) a pressure-sensitive adhesive for optical use wherein the (a-1) oxyalkylene group-containing (meth) acrylic monomer is 2- (methoxy) ethyl acrylate or ethylcarbitol acrylate,

(f) a pressure-sensitive adhesive for optics, which is subjected to crosslinking treatment of the pressure-sensitive adhesive material by heat treatment and active energy ray irradiation treatment,

(g) a pressure-sensitive adhesive sheet obtained by inserting an optical pressure-sensitive adhesive so that the optical pressure-sensitive adhesive sheet with the release film is in contact with the release layer side of two release films

.

According to the present invention, it is possible to provide an antistatic property which has a surface resistivity of about 5 x ¹⁰ < 10 ^{> [} Omega] / quadrature or less and which is used for laminating an optical member such as a polarizing plate on an adherend, A pressure-sensitive adhesive for optical use which has durability and also has an antistatic property (non-sticking property) of an antistatic agent, a pressure-sensitive adhesive sheet with a release film using the pressure-sensitive adhesive for optical, and a layer comprising the pressure- And an optical member with a pressure-sensitive adhesive layer provided on the optical member of the pressure-sensitive adhesive layer.

1 is a perspective view showing an example of the structure of a polarizing plate;
2 is an explanatory view showing a method for evaluating the light leakage property of a polarizing plate with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples;

First, the optical pressure-sensitive adhesive of the present invention will be described.

(A) a (meth) acrylic acid ester copolymer having the following components as constituent units, (B) a (meth) acrylic acid ester having a reactive group-containing (meth) acrylic monomer as a constituent unit (A) and a component (B) in a mass ratio of from 100: 1 to 100: 50, wherein the mass ratio of the component (A) to the component Is crosslinked.

[Adhesive forming material]

The pressure-sensitive adhesive material used in the pressure-sensitive adhesive for optical use of the present invention is a pressure-sensitive adhesive material which is composed of (A) a (meth) acrylic acid ester having the following component (a-1), component (a- (B) a (meth) acrylic acid ester copolymer having a reactive (meth) acrylic monomer as a constituent unit, (C) an active energy ray curable compound, (D) an antistatic agent, and ) Crosslinking agent. The active energy ray in the active energy ray curable compound (C) refers to an energy ray in the electromagnetic wave or charged particle ray, that is, ultraviolet rays or electron rays.

((A) ( Meta ) Acrylic acid ester copolymer)

The (meth) acrylic acid ester copolymer of component (A) in the pressure-sensitive adhesive agent-forming material is prepared by copolymerizing 5 to 90 mass% of the (a-1) oxyalkylene group- Less than 10% by mass of a (meth) acrylic monomer, and (a-3) a (meth) acrylic acid alkyl ester as essential constitutional units.

In the present invention, (meth) acrylic acid ester means both of acrylic acid ester and methacrylic acid ester. The same is true of other similar terms.

An optical pressure-sensitive adhesive of the present invention, at the same time, the surface resistivity to be used when laminating the optical members such as a polarizing plate to an adherend having a 5 × ¹⁰ 10 □ or less in antistatic property and a good sleep adhesion with the releasable and internal light The (meth) acrylic acid ester copolymer of component (A) is obtained by copolymerizing the components (a-1) and (a-1) in the presence of an anti- 2) and (a-3) as essential constituent units.

The (meth) acrylic acid ester copolymer (A) preferably has a weight average molecular weight of 1,000,000 or more. If the weight average molecular weight is less than 1,000,000, the durability of adhesion under high temperature and high humidity becomes insufficient, and lifting or peeling may occur. Considering adhesion durability and the like, the weight average molecular weight is more preferably from 1.2 to 2 million, and particularly preferably from 1.3 to 2 million. The molecular weight distribution (Mw / Mn) representing the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 20 or less. When the molecular weight distribution is 20 or less, sufficient adhesion durability is obtained.

The weight average molecular weight and the number average molecular weight are polystyrene reduced values measured by gel permeation chromatography (GPC).

< (a-1) Oxyalkylene group  contain ( Meta ) Acrylic Monomer >

(Meth) acrylic acid ester copolymer (A), the (meth) acrylic monomer component containing an oxyalkylene group (a-1) introduced as an essential constituent unit does not deteriorate durability and reworkability under moist heat conditions Thereby contributing to improving the antistatic property.

Normally, in order for the antistatic agent to exhibit its function in the pressure-sensitive adhesive, it is necessary to stabilize the ionization state of the antistatic agent. For this reason, it is designed to assist the ionization state of the antistatic agent by introducing a hydroxyl group or a carboxyl group into the subject polymer. However, if the content of hydroxyl groups in the main polymer is increased in order to obtain antistatic properties at a level of 5 10 ¹⁰ ? /? Or less, the hydrophilic property of the pressure-sensitive adhesive becomes too high and durability under moist heat conditions deteriorates. In addition, if the content of the carboxyl group in the polymer is increased, the workability is deteriorated. On the other hand, when the component (a-1) is introduced as in the present invention, the ionization state of the antistatic agent can be stabilized without causing a problem of increasing the content of hydroxyl groups or carboxyl groups. Further, the oxygen atom of the oxyalkylene group derived from the monomer acts weakly as an antistatic agent, thereby contributing to formation of an environment in which a cationic paper such as Li ⁺ can move freely in the ionized state. Therefore, the function can be more effectively exerted than when the function of an antistatic agent is exerted only with a hydroxyl group or a carboxyl group as a functional group in the subject polymer.

The oxyalkylene group in the (a-1) oxyalkylene group-containing (meth) acrylic monomer component preferably has 2 to 4 carbon atoms. The oxyalkylene group having 2 to 4 carbon atoms may be either linear or branched and specifically includes an oxyethylene group, an oxypropylene group (branched), an oxytrimethylene group, an oxybutylene group (branched) And an oxytetramethylene group.

The number of these oxyalkylene groups is 1 or more, and the upper limit thereof is preferably about 10 to obtain a (meth) acrylic acid ester copolymer of component (A) having the above-mentioned weight average molecular weight, more preferably about 5 , And more preferably about 3. The oxyalkylene group is preferably an alkyloxyalkylene group. The alkyl of the alkyloxyalkylene group is preferably 1 to 14 carbon atoms from the viewpoint of not compromising the antistatic property of the pressure-sensitive adhesive. From this viewpoint, it is particularly preferable that the alkyl group is a C1-4 alkyl group. From the viewpoint of the performance of the optical pressure-sensitive adhesive of the present invention, the oxyalkylene group-containing (meth) acrylic monomer containing (a-1) oxyalkylene group is preferably 2- (methoxy) ethyl acrylate or ethyl carbitol acrylate The rate is preferred.

The (a-1) oxyalkylene group-containing (meth) acrylic monomer unit may be introduced singly or in combination of two or more, and the content of the (meth) acrylic acid ester copolymer in the Is preferably from 5 to 90% by mass, more preferably from 10 to 50% by mass, and still more preferably from 15 to 25% by mass, from the viewpoint of the performance of the optical pressure-sensitive adhesive.

< (a-2) Reactive group-containing ( Meta ) Acrylic Monomer >

In the (meth) acrylic acid ester copolymer of the component (A), the reactive group in the reactive group-containing (meth) acrylic monomer component (a-2) introduced as an essential constituent unit is a crosslinking A hydroxyl group, a carboxyl group, an amino group, an epoxy group and the like can be mentioned. However, in the present invention, a hydroxyl group is preferable.

Specific examples of the hydroxyl group-containing (meth) acrylic monomers in the component (a-2) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl , (Meth) acrylic acid hydroxyalkyl esters such as 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. Among these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate may be used alone or in combination of two or more. Methacrylic acid ester copolymer can be easily produced.

The content of the reactive group-containing (meth) acrylic monomer unit (a-2) in the (meth) acrylic acid ester copolymer of the component (A) is preferably in the range of By mass and less than 10% by mass, preferably 0.1% by mass or more. From the standpoint of reworkability of the pressure-sensitive adhesive to be obtained, the content of the reactive group-containing (meth) acrylic monomer unit is particularly preferably 1 to 5% by mass.

< (a-3) ( Meta ) Acrylic acid Alkyl  Esther>

In the (meth) acrylic acid ester copolymer of the component (A), the (a-3) (meth) acrylic acid alkyl ester component to be introduced as an essential constitutional unit is not particularly limited and includes, for example, (Meth) acrylic acid ester having 1 to 20 carbon atoms. Examples of the (meth) acrylic acid ester in which the alkyl group of the ester moiety has 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (Meth) acrylate, dodecyl (meth) acrylate, dodecyl (meth) acrylate, isobutyl (meth) acrylate, isobutyl Stearyl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

Among these compounds, butyl (meth) acrylate is particularly preferable because it is possible to easily obtain a (meth) acrylic acid ester copolymer which can obtain a suitable adhesive property and has a weight average molecular weight of 100,000 or more. The content of the (a-3) (meth) acrylic acid alkyl ester as a constituent component in the (A) (meth) acrylic acid ester copolymer is preferably in the range of But it is usually 0.1 mass% or more. The content is preferably 40 to 89.9% by mass, particularly preferably 70 to 84% by mass from the viewpoint of improving compatibility with the (B) (meth) acrylic acid ester copolymer and the (C) active energy ray curable compound Do.

((B) ( Meta ) Acrylic acid ester copolymer)

The (meth) acrylic acid ester copolymer (B) in the pressure-sensitive adhesive agent-forming material preferably has a weight average molecular weight of at least 1,000,000, similarly to the (meth) acrylic acid ester copolymer of the component (A). If the weight average molecular weight is less than 1,000,000, the durability of adhesion under high temperature and high humidity becomes insufficient, and lifting or peeling may occur. Considering adhesion durability and the like, the weight average molecular weight is more preferably from 1.2 to 2 million, and particularly preferably from 1.3 to 2 million. The molecular weight distribution (Mw / Mn) representing the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 20 or less. When the molecular weight distribution is 20 or less, sufficient adhesion durability is obtained.

The weight average molecular weight and the number average molecular weight are polystyrene reduced values measured by gel permeation chromatography (GPC).

The (meth) acrylic acid ester copolymer of the component (B) is a copolymer having an essential structural unit and a reactive group-containing (meth) acrylic monomer component (hereinafter may be referred to as "(b-1) A hydroxyl group, a carboxyl group, an amino group, an epoxy group and the like can be mentioned, but in the present invention, the reactive group is preferably a carboxyl group.

Specific examples of the carboxyl group-containing monomer in the component (B) include (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. These may be used singly or in combination of two or more kinds. Among them, (meth) acrylic acid esters such as (meth) acrylic acid esters of desirable.

The (meth) acrylic acid ester copolymer of component (B) has, as a constitutional unit, a (meth) acrylic acid alkyl ester component (hereinafter occasionally referred to as "(b-2)") usually having no reactive group.

The (meth) acrylic acid alkyl ester having no reactive group (b-2) is not particularly limited and may be the same as that used in the component (a-3), that is, the ester group in which the number of carbon atoms in the alkyl moiety is 1 to 20 Methacrylic acid esters. These may be used alone or in combination of two or more.

Among these compounds, (meth) acrylic acid ester polymer (B) having a weight-average molecular weight of not less than 1,000,000 can be obtained easily with butyl (meth) acrylate as appropriate in the case of the component (a- It is preferable in that it can be manufactured.

The content of the carboxyl group-containing monomer component in the (meth) acrylic acid ester copolymer of the component (B) is preferably 5 to 20% by mass. When the content is more than 20% by mass, the adhesion strength with the liquid crystal cell increases and the re-peeling property (reworkability) may be impaired. On the other hand, when the content is less than 5% by mass, the durability under high temperature tends to decrease . From this viewpoint, the content is more preferably 5 to 15% by mass. The content of the component (b-2) as a component is preferably 80 to 95 mass%, particularly preferably 85 to 95 mass%.

In the pressure-sensitive adhesive agent-forming material, the content ratio of the (meth) acrylic acid ester copolymer of the component (A) and the (meth) acrylic acid ester copolymer of the component (B) , And a mass ratio of 100: 1 to 100: 50, preferably 100: 2.5 to 100: 30, and more preferably 100: 5 to 100: 20.

((C) active Energy line  Curable compound)

As the active energy ray curable compound as the component (C) in the pressure-sensitive adhesive agent-forming material, a polyfunctional (meth) acrylate-based monomer having a molecular weight of less than 1,000 is preferably used.

Examples of the polyfunctional (meth) acrylate monomer having a molecular weight of less than 1,000 include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) Acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, (Meth) acrylate, di (methoxy) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (Meth) acrylate such as cyclohexyl di (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, ethylene oxide modified hydrophthalic acid di (Meth) acrylate, neopentylglycol-modified trimethylolpropane di (meth) acrylate, adamantane di (meth) acrylate, 9,9-bis [4- Dioctyloxy) ethoxy] phenyl] fluorene; (Meth) acrylates such as trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylol propane tri (Meth) acrylate, and tris (acryloxyethyl) isocyanurate; Quaternary type such as diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; Pentionic type such as propionic acid-modified dipentaerythritol penta (meth) acrylate; Dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

In the present invention, these multifunctional (meth) acrylate monomers may be used singly or in combination of two or more. Among them, those containing a cyclic structure in the skeleton structure desirable. The cyclic structure may be a carbon cyclic structure, a heterocyclic structure, a monocyclic structure or a polycyclic structure. Examples of such multifunctional (meth) acrylate monomers include monomers having an isocyanurate structure such as di (acryloxyethyl) isocyanurate and tris (acryloxyethyl) isocyanurate, Oleic acid-modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol-modified trimethylolpropane diacrylate, adamantanediacrylate, and the like are preferable.

As the component (C), an acrylate oligomer having an active energy ray-curable type may be used. Examples of such acrylate oligomers include polyester acrylate type, epoxy acrylate type, urethane acrylate type, polyether acrylate type, polybutadiene acrylate type, and silicone acrylate type.

Examples of the polyester acrylate oligomer include polyester oligomers obtained by esterification of a hydroxyl group of a polyester oligomer having a hydroxyl group at both terminals by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, Can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a carboxylic acid with (meth) acrylic acid. The epoxy acrylate oligomer can be obtained, for example, by reacting an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin with (meth) acrylic acid to effect esterification. Also, an epoxy acrylate oligomer of a carboxyl modified epoxy resin obtained by partially modifying the epoxy acrylate oligomer with a dibasic carboxylic anhydride may be used. The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by the reaction of a polyether polyol or a polyester polyol with a polyisocyanate with (meth) acrylic acid, and a polyol acrylate The system oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

delete

The weight average molecular weight of the acrylate oligomer is preferably 50,000 or less, more preferably 1,000 to 50,000, and still more preferably 3,000 to 40,000 in terms of standard polymethylmethacrylate measured by GPC .

These acrylate oligomers may be used singly or in combination of two or more.

In the present invention, an adduct acrylate-based polymer having a group having a (meth) acryloyl group introduced into the side chain may be used as the component (C). Such adduct acrylate polymer is obtained by copolymerizing a (meth) acrylic acid alkyl ester described in the above-mentioned (meth) acrylic acid ester copolymer of component (A) with a monomer having a crosslinkable functional group (Meth) acryloyl group and a compound having a group capable of reacting with a crosslinkable functional group to a part of the crosslinkable functional group of the copolymer. The weight average molecular weight of the adduct acrylate polymer is usually 500,000 to 2,000,000 in terms of polystyrene.

In the present invention, as the component (C), one type may be appropriately selected from among the above-mentioned polyfunctional acrylate monomer, acrylate oligomer and adduct acrylate polymer, or two or more types may be selected But a multifunctional (meth) acrylate monomer having a molecular weight of less than 1,000 is preferred.

The content of the active energy ray-curable compound (C) in the pressure-sensitive adhesive agent-forming material is preferably in the range of from 100 parts by mass to 100 parts by mass in total of the components (A) and (B) More preferably from 1 to 50 parts by mass, still more preferably from 2 to 30 parts by mass, still more preferably from 4 to 25 parts by mass.

((D) antistatic agent)

In the pressure-sensitive adhesive agent-forming material, an antistatic agent can be used as the component (D) in order to impart an antistatic property to the resulting optical pressure-sensitive adhesive having a surface resistivity of about 5 × 10 ¹⁰ Ω / □ or less.

The antistatic agent is not particularly limited and may be suitably selected from known antistatic agents conventionally used for imparting antistatic properties to an optical pressure-sensitive adhesive. For example, those containing an ionic compound can be used.

<Ionic Compound>

The ionic compound includes, for example, a compound represented by the following general formula (1): &lt; EMI ID =

(Z ^{a +} ) _m · (A ^{b -} ) _n ... (One)

A, b, m and n are each an integer of 1 to 3, satisfying the relationship of a x m = b x n. In the formula, Z ^{a +} represents a cation, A ^{b -} represents an anion, When Z ⁺ is in ^a plurality, ^a plurality of Z ⁺ may be the same or different, A ^b-is is be the same or different; ^- if there is a plurality, the plurality of A ^b.

The ionic compound may be in a solid form or a liquid form, and the cation represented by Z ^{a +} may be an inorganic cation or an organic cation.

" Z ^{a +} Quot; cation &quot;

Among the cations represented by Z ^{a +} in the general formula (1), examples of the inorganic cations include Li ⁺ , Na ⁺ and K ^{+ which} are alkali metal cations, and among them, excellent antistatic properties Li ^&lt; ^{+ &} gt ^; or K ^{& lt} ; ^{+ &} gt ^; is particularly preferable.

On the other hand, examples of the organic cation include the following cations.

Examples thereof include pyridinium-based cations, piperidinium-based cations, pyrrolidinium-based cations, cations having a pyrrolene skeleton, and cations having a pyrrole skeleton. Specific examples thereof include 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl- Methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1,1-dimethylpyrrolidinium cation, Methyl-1-pyrrolidinium cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethyl Carbazole cation, and the like.

For example, an imidazolium cation, a tetrahydropyrimidinium cation, a dihydropyrimidinium cation, and the like. Specific examples include 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1- Methylimidazolium cation, a 1,2-dimethyl-3-propylimidazolium cation, a 1-ethyl-2,3-dimethylimidazolium cation, a 1-butyl- Methylimidazolium cation, 1-hexyl-2,3-dimethylimidazolium cation, 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-tri Methyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5 Tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,3-dimethyl-1,4-dihydropyridine Diiodopyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, 1,2,3-trimethyl -1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,6-di And a hydropyrimidinium cation.

For example, pyrazolium cations and pyrazolinium cations. Specific examples thereof include 1-methylpyrazolium cation, 3-methylpyrazolium cation and 1-ethyl-2-methylpyrazolinium cation.

Examples thereof include tetraalkylammonium cations, trialkylsulfonium cations and tetraalkylphosphonium cations, and those in which a part of the alkyl group is substituted with an alkenyl group, an alkoxyl group or an epoxy group. Specific examples include tetramethylammonium cations, tetraethylammonium cations, tetrabutylammonium cations, tetrahexylammonium cations, triethylmethylammonium cations, tributylethylammonium cations, trimethylhexylammonium cations, trimethyldecylammonium cations, N, N Diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyl trimethylammonium cation, N, N, N-diethylamino ammonium cation, N, N-diethyl ammonium cation, N, N-diethyl ammonium cation, Tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetraethylphosphonium cation, tetraethylphosphonium cation, tetraethylphosphonium cation, tetraethylphosphonium cation, tetraethylphosphonium cation, There may be mentioned tetrahexylammonium phosphonium cation, a triethyl methyl phosphonium cation, a tributyl ethyl phosphonium cation, a trimethyl decyl phosphonium cation, a diallyl dimethyl ammonium cation.

" A ^{b -} Quot; anion &quot;

On the other hand, in the general formula (1), the anion represented by A ^{b -} is not particularly limited as long as it can ionically bond with the cation to form an ionic compound. Examples thereof include F ^- , Cl ^{-, Br -, I -,} AlC1 4 -, Al 2 C1 7 -, BF 4 -, PF 6 -, SCN -, ClO 4 -, NO 3 -, CH 3 COO -, CF 3 COO -, CH 3 SO _{^{3 -, CF 3 SO 3 -}} , (CF 3 SO 2) 2 N -, (F 2 SO 2) 2 N -, (CF 3 SO 2) 3 C-, AsF 6 -, SbF 6 -, NbF 6 - _{^{, TaF 6 -, F (HF}} ) n -, (CN) 2 N -, C 4 F 9 SO 3 -, (C 2 F 5 SO 2) 2 N -, C 3 F 7 COO -, (CF 3 SO ₂ ) (CF ₃ CO) N ^- and the like. Among them, the anion containing a fluorine atom is preferable because it gives an ionic compound having a low melting point, and (F ₂ SO ₂ ) ₂ N ^- or (CF ₃ SO ₂ ) ₂ N ^- is particularly preferable.

When the cation represented by Z ^{a +} is Li ⁺ , examples of the ionic compound include LiBr, LiI, LiBF ₄ , LiPF ₆ , LiSCN, LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (F ₂ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C, lithium octylbenzenesulfonate, lithium dodecylbenzenesulfonate and lithium dibutylnaphthalenesulfonate. Among them, particularly preferred are Li (CF ₃ SO ₂ ) ₂ N [lithium bis (trifluoromethanesulfonyl) imide], Li (CF ₃ SO ₂ ) ₃ C [lithium tris (trifluoromethanesulfonyl) ] Or Li (F ₂ SO ₂ ) ₂ N [lithium bis (difluorosulfonyl) imide].

When the cation represented by Z ^{a +} is K ⁺ , the ionic compound may be K (F ₂ SO ₂ ) ₂ N [potassium bis (difluorosulfonyl) imide] or K (CF ₃ SO ₂ ) ₂ N [potassium bis (trifluoromethanesulfonyl) imide] are preferable.

When the cation represented by Z ^{a +} is a pyridinium-based cation, examples of the ionic compound include 1-ethylpyridinium hexafluorophosphate, 1-butylpyridinium hexafluorophosphate, 1-hexyl- 4-methylpyridinium hexafluorophosphate, 1-octyl-4-methylpyridinium hexafluorophosphate and the like are preferable.

The ionic compound represented by the general formula (1) may be used singly or in combination of two or more kinds.

The reactive quaternary ammonium base-containing compound is also preferable as an example satisfying the general formula (1).

&Lt; Reactive quaternary ammonium base-containing compound >

As the reactive quaternary ammonium base-containing compound, for example, a compound represented by the following general formula (2) can be cited:

...(2)

...(2)

(Wherein R represents a hydrogen atom or a methyl group).

In the present invention, the quaternary ammonium base-containing monomers may be used singly or in combination of two or more, or in combination with the above-mentioned ionic compounds.

When the crosslinking is carried out by irradiating an active energy ray by containing the quaternary ammonium base-containing monomer in the pressure-sensitive adhesive-forming material, the active energy ray-curable compound present in the material and the quaternary ammonium base- Thus, a quaternary ammonium base is introduced into the obtained optical pressure-sensitive adhesive to give an antistatic property.

The content of the antistatic agent as the component (D) in the pressure-sensitive adhesive agent-forming material depends on the type of the antistatic agent, but the antistatic property of the resulting pressure sensitive adhesive for optical properties is imparted with a surface resistivity of about 5 × 10 ¹⁰ Ω / (A), (B), and (C) is preferably in the range of about 0.1 to 10 parts by mass, and more preferably in the range of about 0.1 to 10 parts by mass, in terms of the anti- Preferably 0.5 to 5 parts by mass, more preferably 0.5 to 3 parts by mass.

The pressure-sensitive adhesive agent-forming material may optionally contain (E) a crosslinking agent, a silane coupling agent, a photopolymerization initiator, and various additives such as an antioxidant, an ultraviolet absorbent, a light stabilizer, a leveling agent, .

((E) Cross-linking agent )

The pressure-sensitive adhesive material may optionally contain a crosslinking agent as the component (E). The crosslinking agent is not particularly limited, and any of those conventionally used as a crosslinking agent in the acrylic pressure-sensitive adhesive may be appropriately selected and used. Examples of such a crosslinking agent include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides and metal salts, Polyisocyanate compounds are preferably used.

Examples of the polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, and aromatic polyisocyanates such as hexamethylene diisocyanate Alicyclic polyisocyanates such as aliphatic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and their alicyclic polyisocyanates such as burette, isocyanurate, And adducts which are reaction products with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil, and the like.

In the present invention, these crosslinking agents may be used singly or in combination of two or more kinds. The amount of the crosslinking agent to be used depends on the kind of the crosslinking agent, but is usually 0.01 to 20 parts by mass, preferably 0 to 1 to 10 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B) .

( Silane Coupling agent )

When an optical member such as a polarizing plate is bonded to a glass cell or the like by using the obtained optical pressure-sensitive adhesive by incorporating a silane coupling agent as necessary into the pressure-sensitive adhesive agent-forming material, adhesion between the pressure- . As the silane coupling agent, an organosilicon compound having at least one alkoxysilyl group in the molecule is preferable because it has good compatibility with the pressure-sensitive adhesive component and has light transmission property, for example, substantially transparent. The amount of the silane coupling agent added is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 5 parts by mass relative to 100 parts by mass of the total amount of the component (A), the component (B) and the component (C) desirable.

Specific examples of the silane coupling agent include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane and methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2 - (3,4-epoxycyclohexyl) ethyltrimethoxysilane, a silicon compound having an epoxy structure such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane , Amino group-containing silicon compounds such as N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and 3-chloropropyltrimethoxysilane. These may be used singly or in combination of two or more kinds.

( Photopolymerization initiator )

When the active energy ray-curable compound (C) contained therein is irradiated with an active energy ray such as ultraviolet rays, the above-mentioned pressure-sensitive adhesive agent-forming material may contain a photopolymerization initiator if necessary. When an electron beam is used as an active energy ray, a photopolymerization initiator may not be used.

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, Diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1- Phenyl) -2-morpholinopropane-1-one, 4- (2-hydroxyethoxy) phenyl- Benzoquinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-ethyl anthraquinone, 2-ethyl anthraquinone, 2- 2-amino thioxanthone, 2-ethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl Thioxanthone, benzyl dimethyl ketal, acetophenonedimethyl ketal, p-da 2-methyl-1- [4- (1-methylvinyl) phenyl] propanone], 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, . These compounds may be used singly or in combination of two or more. The compounding amount thereof is usually 0.2 to 20 parts by mass, preferably 1 to 15 parts by mass, per 100 parts by mass of the total active energy ray- Mass part.

(Including a pressure-sensitive adhesive material Coating solution  pharmacy)

The method for preparing the coating liquid containing the pressure-sensitive adhesive material is not particularly limited. For example, a method in which the above-mentioned (meth) acrylic acid ester copolymer of component (A), (meth) acrylic acid ester (E) component and / or a silane coupling agent and / or a photopolymerization initiator, which are used as required, and an antioxidant of the component (C) An additive such as an antioxidant, an ultraviolet absorber, a light stabilizer, a leveling agent, a defoaming agent, and the like are added and stirred to prepare a coating liquid containing the pressure-sensitive adhesive-forming material.

Examples of the solvent include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, alcohols such as methanol, ethanol, propanol and butanol, Ketones such as ethyl ketone, 2-pentanone, isophorone and cyclohexanone, esters such as ethyl acetate and butyl acetate, cellosolve solvents such as ethyl cellosolve, glycols such as propylene glycol monomethylether And col ether-based solvents. These solvents may be used singly or in combination of two or more kinds.

The concentration of the adhesive material in the coating liquid is not particularly limited as long as the coating liquid is suitable for coating.

[Optical Adhesive]

The optical pressure-sensitive adhesive of the present invention can be obtained by applying the pressure-sensitive adhesive obtained by the above-described method using a coating solution containing a pressure-sensitive adhesive material, by a conventionally known method on an adherend such as a release film or an optical member, A layer made of the pressure-sensitive adhesive for optical use of the present invention can be formed.

The crosslinking is carried out by heating the wet coating film formed on the adherend at a temperature of about 40 to 150 DEG C for about 10 seconds to 10 minutes to obtain a crosslinking agent of the component (E) and a crosslinking agent of the component (A) Ester copolymer and the crosslinkable functional group in the (meth) acrylic acid ester copolymer of the component (B) react with each other to effect cross-linking.

On the other hand, crosslinking of the active energy ray curable compound in the coating film occurs by irradiating the coating film on the partially crosslinked adherend with the activation energy ray.

When ultraviolet rays are used as the active energy ray, this ultraviolet ray is obtained from a high-pressure mercury lamp, an electrodeless lamp, a xenon lamp and the like, while the electron beam can be obtained by an electron beam accelerator or the like. Among these active energy rays, ultraviolet rays are particularly preferable. When an electron beam is used, a pressure-sensitive adhesive can be formed without adding a photopolymerization initiator.

The amount of the active energy ray to be applied to the pressure-sensitive adhesive material is suitably selected so as to obtain a pressure-sensitive adhesive having a desirable storage elastic modulus and an adhesive force to an alkali-free glass. In the case of ultraviolet rays, however, the light intensity is 50 to 1000 mW / cm & Cm &lt; 2 &gt; and in the case of electron beam, 10 to 1000 krad.

Next, the optical adhesive sheet with a release film of the present invention will be described.

[Adhesive sheet for optical with release film]

The optical pressure-sensitive adhesive sheet with a release film of the present invention is an optical pressure-sensitive adhesive sheet with a release film formed using the optical pressure-sensitive adhesive of the present invention.

Specific examples of the optical adhesive sheet with a release film include an optical adhesive sheet in which the above-mentioned optical adhesive of the present invention is inserted in contact with the release layer side of two release films. The optical pressure-sensitive adhesive sheet having the release film can be produced, for example, as follows.

First, a coating liquid containing the above-described pressure-sensitive adhesive material is coated on the release layer of the release film by a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, , And dried to form a pressure-sensitive adhesive forming material layer. Subsequently, another release film having a peel strength different from that of the release film was stuck on the pressure-sensitive adhesive material layer so that the release layer was in contact with the release film, and then an active energy ray was irradiated to produce an optical pressure- do. Alternatively, a pressure-sensitive adhesive material layer may be formed on the release layer of one of the release films, irradiated with an active energy ray after drying, and another release film may be adhered thereon such that the release layer surface is in contact with the release layer. .

The thickness of the optical pressure-sensitive adhesive sheet (not including the release film) is usually about 5 to 100 탆, preferably 10 to 5.0 탆.

As the release film, a release agent such as a silicone resin is applied to a plastic film such as a polyester film such as polyethylene terephthalate, polystyrene terephthalate, or polyethylene naphthalate, or a polyolefin film such as polypropylene or polyethylene to form a release layer And the like. The thickness of the release film is not particularly limited, but is usually about 19 to 150 mu m.

[Optical member with pressure-sensitive adhesive layer]

The present invention also provides an optical member with a pressure-sensitive adhesive layer having a layer made of the above-mentioned optical pressure-sensitive adhesive of the present invention on the optical member.

Examples of the optical member include a polarizing plate, a retardation plate, an optical compensation film, a reflective sheet, and a brightness enhancement film. Among them, a polarizing plate and a retardation plate are preferably used. The thickness of the pressure-sensitive adhesive layer made of the optical pressure-sensitive adhesive of the present invention is usually about 5 to 100 탆, preferably 10 to 50 탆, more preferably 10 to 30 탆.

The optical member with a pressure-sensitive adhesive layer can be produced, for example, as follows.

The adhesive layer is formed on the release layer of the release film by forming a pressure-sensitive adhesive material layer on the release layer, then attaching an optical member thereon, removing the release film, The optical member with a pressure-sensitive adhesive layer can be manufactured by irradiating an active energy ray from the side of the release film without removing the release film.

In the optical member with a pressure-sensitive adhesive layer of the present invention, for example, when the optical member is a polarizing plate, it is a polarizing plate with a pressure-sensitive adhesive layer. The polarizing plate with a pressure-sensitive adhesive layer can be used, for example, for adhering to a liquid crystal glass cell. The polarizing plate may be preferably made of a single polarizing film, but a polarizing plate in which the polarizing film and the viewing angle increasing film are integrated can be used particularly preferably.

As a polarizing plate in which the polarizing film and the viewing angle expanding film are integrated, for example, a polarizing film obtained by attaching a triacetylcellulose (TAC) film to the both surfaces of a polyvinyl alcohol polarizer, for example, A viewing angle magnification function layer made of liquid crystal is formed by coating or a viewing angle magnification film is adhered with an adhesive. In this case, it is preferable that the optical pressure-sensitive adhesive of the present invention is formed on the side of the viewing angle increasing function layer or the viewing angle increasing film.

The liquid crystal display device produced by adhering the polarizing plate with a pressure-sensitive adhesive layer to a liquid crystal glass cell is less liable to light leakage even under a high temperature and high humidity environment and has excellent durability of adhesion between the polarizing plate and the liquid crystal glass cell.

The polarizing plate with a pressure-sensitive adhesive layer can be suitably used also when it is disposed on a liquid crystal cell via a retardation plate in order to improve viewing angle characteristics of the liquid crystal display device. That is, a polarizing plate with a pressure-sensitive adhesive layer is obtained by applying the optical pressure-sensitive adhesive of the present invention to a polarizing plate composed of a single polarizing film, and this polarizing plate is bonded to the retardation plate to produce a new optical member. As another method as described above, it is also possible to apply a pressure-sensitive adhesive for optical use of the present invention to a retardation plate to obtain a pressure-sensitive adhesive sheet with a pressure-sensitive adhesive layer, and to bond it to a polarizing plate. The newly obtained optical member may be bonded to the liquid crystal glass cell with an adhesive so that the phase difference plate side is in contact with the optical member. The pressure-sensitive adhesive for bonding the retarder to the liquid crystal glass cell is not particularly limited, and a pressure-sensitive adhesive that can be usually used for bonding the polarizing plate and the liquid crystal glass cell can be used. It is also preferable to apply the optical pressure-sensitive adhesive of the present invention to this new optical member to obtain a new optical member with a pressure-sensitive adhesive layer and bond it to the liquid crystal glass cell.

(Properties of the pressure-sensitive adhesive layer of the optical member with the pressure-sensitive adhesive layer)

The adhesive force, the workability, the heavy stripping, the resistance to light leakage, the antistatic property and the non-sticking property of the antistatic agent of the optical member with a pressure-sensitive adhesive layer thus obtained according to the present invention can be evaluated by the following methods.

<Workability>

The reworkability means that the optical member is bonded to the liquid crystal cell via the pressure-sensitive adhesive layer so that the pressure-sensitive adhesive does not adhere to the surface of the liquid crystal cell even after a predetermined period of time and the optical member with the pressure- It says.

In the present invention, the pressure-sensitive adhesive layer of the polarizing plate with a pressure-sensitive adhesive layer is bonded to the glass surface, and the reworkability is judged by whether or not the adhesive force after 21 days is within a predetermined value. That is, if the adhesive force after 21 days has passed 30 N / 25 mm or less, it can be judged that there is a normal reworkability. In addition, it is particularly preferable that the reworkability is 20 N / 25 mm or less, and particularly preferably 15 N / 25 mm or less.

The optical pressure-sensitive adhesive of the present invention can have a pressure-sensitive adhesive force of 20 N / 25 mm or less after 21 days of adhesion of the polarizing plate with a pressure-sensitive adhesive layer formed thereon, depending on conditions.

The test method will be described later in detail.

< Light Leakage Resistance >

The polarizing plate with a pressure-sensitive adhesive layer of the present invention can have a DELTA L ^* value in a range of 1.0 or less, or 1.0 to 2.0, in light-leak-resistance measurement described later in detail, and is excellent in leak resistance.

< A heavy lifter >

In the present invention, the term refers to a phenomenon in which the peeling force of the peeling film rises over time when the peeling film is peeled after the optical member with the adhesive layer provided with the peeling film on the pressure-sensitive adhesive layer is left for a predetermined period. In the present invention, with respect to the polarizing plate with pressure-sensitive adhesive layer after seasoning, the peeling force of the release film on the pressure-sensitive adhesive layer immediately after the elapse of the seasoning and the difference of the peeling force after leaving for 21 days at 70 deg. It says. Specifically, the difference in peeling force is preferably 30 mN / 25 mm or less, more preferably 20 mN / 25 mm or less, and particularly preferably 10 mN / 25 mm or less.

The polarizing plate with a pressure-sensitive adhesive layer is kept in a state in which the pressure-sensitive adhesive layer is protected by a release film until the polarizing plate is attached to the liquid crystal cell. When the storage period is prolonged, the peeling force for peeling off the peeling film is increased, and the surface of the pressure-sensitive adhesive layer is damaged when the peeling film is peeled off. Therefore, it is required not to be heavy.

"How to measure"

The polarizing plate with a pressure-sensitive adhesive layer provided with a release film (having a thickness of 38 mu m) is cut into a size of 25 mm width x 100 mm length. The cut polarizer with a pressure-sensitive adhesive layer is allowed to stand for 7 days under a condition of 23 DEG C and a relative humidity of 50% RH (seasoning treatment). Next, a pressure sensitive adhesive having a strong adhesive force was laminated on the polarizing plate side of the polarizing plate with pressure sensitive adhesive layer after seasoning treatment, and the pressure sensitive adhesive was fixed on the glass substrate. Then, the peeling force was measured under the following conditions (peeling force?).

Peeling speed: 300 mm / min

Peeling angle: 180 °

On the other hand, the polarizing plate with pressure-sensitive adhesive layer after completion of the seasoning treatment was allowed to stand at 70 DEG C for 21 days. Thereafter, similarly, the polarizing plate with a pressure-sensitive adhesive layer was fixed to the glass substrate and the peeling force was measured (peeling force?).

Quot; peeling force [beta] - peeling force [alpha] &quot;

In the optical pressure-sensitive adhesive of the present invention, the value of the &quot; peel force? - peel force? 'Can be suppressed to about 5 mN / 25 mm, depending on the conditions, and the heavy sticking can be suppressed.

<Antistatic performance>

A polarizing plate with a pressure-sensitive adhesive layer on which a release film was laminated on the pressure-sensitive adhesive layer surface was cut into 50 mm in length and width, and used as a measurement sample. The measurement sample was conditioned for 24 hours under the conditions of 23 캜 and 50% RH, peeled off the release film, and the surface of the pressure-sensitive adhesive layer exposed in accordance with JIS K 6911 was measured at a voltage of 100 V And the antistatic property is evaluated. The surface resistivity of the pressure-sensitive adhesive layer of the polarizing plate with a pressure-sensitive adhesive layer of the present invention is less than 5 x ¹⁰ &lt; 10 ^{&gt; [} Omega] / square, and has good antistatic performance.

&Lt; Antistatic agent Non-ferrous >

The release film on the pressure-sensitive adhesive layer of the polarizing plate with a pressure-sensitive adhesive layer is peeled off, and the exposed pressure-sensitive adhesive layer side is attached to a glass plate to obtain a measurement sample.

The measurement sample was allowed to stand for 24 hours under a wet heat condition of 60 占 폚 and relative humidity of 90% RH and thereafter cooled to a moist heat condition of 23 占 폚 and relative humidity of 50% RH and observed with naked eyes through glass, The non-solidifying property of the inhibitor is evaluated. The optical pressure-sensitive adhesive of the present invention is colorless and transparent even after the above conditions, and the antistatic property of the antistatic agent is good.

Example

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The performance of the optical pressure-sensitive adhesive obtained in each example and the performance of the polarizing plate with a pressure-sensitive adhesive layer were determined in the following manner.

< The pressure-  Performance of Attached Polarizer>

(1) Adhesion (adhesion to alkali-free glass)

The polarizing plate with a pressure-sensitive adhesive layer is allowed to stand for 7 days under conditions of 23 캜 and relative humidity of 50% RH.

Thereafter, the obtained polarizing plate with a pressure-sensitive adhesive layer was cut into a size of 25 mm in width × 100 mm in length using a cutting device (product of Ogino Seiki Co., Ltd., "Super Cutter" Respectively.

Then, the release film was peeled off from the obtained measurement sample, and then bonded to an alkali-free glass (Eagle XG, product of Corning Incorporated).

Subsequently, the alkali-free glass to which the measurement sample was bonded was placed in an autoclave (product of Kurihara Seishakusho Co., Ltd.), pressurized at 0.5 MPa, 50 캜 for 20 minutes, % RH for 1 day and 21 days.

Subsequently, with respect to the measurement sample, a tensile tester ("Tensilon" manufactured by Orientech Co., Ltd.) was used to measure the adhesive force under the following conditions.

Peeling speed: 300 mm / min

Peeling angle: 180 °

If the adhesive force after the lapse of 21 days after the attachment is 30 N / 25 mm or less, it can be judged that there is normal reworkability. If it is 20 N / 25 mm or less, the reworkability is excellent, and if it is 15 N / 25 mm or less, it is particularly preferable.

(2) Surface resistivity

The polarizing plate with a pressure-sensitive adhesive layer was cut to 50 mm in length and width, and used as a measurement sample. The measurement sample was conditioned for 24 hours under conditions of 23 캜 and 50% RH, peeled off the release film, and the surface of the pressure-sensitive adhesive layer exposed in accordance with JIS K 6911 was peeled off from the surface of the pressure- MCP-HT450 &quot;) at an applied voltage of 100 V to determine the surface resistivity. When the surface resistivity is 5 10 ¹⁰ ? /? Or less, the antistatic performance is good.

(3) Non-stoichiometry of antistatic agent

The release film on the pressure-sensitive adhesive layer of the polarizing plate with a pressure-sensitive adhesive layer was peeled off, and the exposed pressure-sensitive adhesive layer side was attached to a glass plate to obtain a measurement sample.

The measurement sample was allowed to stand for 24 hours under a wet heat condition of 60 占 폚 and 90% RH, and thereafter cooled to a moist heat condition of 23 占 폚 and relative humidity of 50% RH. Respectively.

○: colorless transparent thing

Δ: Very slightly cloudy

X: aggregate visible on the entire surface

(4) Peel force

A polarizing plate with a pressure-sensitive adhesive layer provided with a release film (SP-PET3811, thickness 38 占 퐉, manufactured by LINTEC CO., LTD.) Was cut into a size of 25 mm in width × 100 mm in length. The cut polarizer with a pressure-sensitive adhesive layer was allowed to stand for 7 days under a condition of 23 캜 and a relative humidity of 50% RH (seasoning treatment). Then, a pressure sensitive adhesive having a strong adhesive force was laminated on the polarizing plate side of the pressure-sensitive adhesive layer polarizing plate after the seasoning treatment, and the pressure-sensitive adhesive was fixed on the glass substrate. Thereafter, the peeling force was measured under the following conditions.

Peel rate; 300 mm / min

Peeling angle: 180.

On the other hand, the polarizing plate with pressure-sensitive adhesive layer after completion of the seasoning treatment was allowed to stand at 70 DEG C for 21 days. Thereafter, similarly, the polarizing plate with a pressure-sensitive adhesive layer was fixed to the glass substrate and the peeling force was measured (peeling force?).

&Quot; Peeling force [beta] - Peeling force [alpha] &quot;

Is preferably 30 mN / 25 mm or less, more preferably 20 mN / 25 mm or less, and particularly preferably 10 mN / 25 mm or less, from the viewpoint of the anti-splash resistance.

(5) Light Leakage Leakability

(Having a discotic liquid crystal layer) with a pressure-sensitive adhesive layer was adjusted to a size of 233 mm x 309 mm by a cutting device (Super cutter "PN1-600", product of Oginose Ikisei Co., Ltd.) Product, "1737"], and then pressed under the conditions of 0.5 MPa and 50 ° C. for 20 minutes with an autoclave manufactured by Kurihara Seisakusho Co., Ltd. The above bonding was carried out so that the polarization axis of the polarizing plate with a pressure-sensitive adhesive layer was in the cross-Nicol state on the front and back of the alkali-free glass. In this state, it was allowed to stand at 80 DEG C for 200 hours. Thereafter, the sample was allowed to stand in an environment of 23 캜 and 50% RH for 2 hours. In the same environment, the light leakage preventing property was evaluated by the following method.

The lightness of each area shown in Fig. 2 was measured by using "MCPD-2000" manufactured by Otsuka Electronics Co., Ltd., and the lightness difference DELTA L ^* was determined by the following equation, And the light leakage resistance was evaluated as follows:

? L ^* = [(b + c + d + e) / 4] -a

(Where a, b, c, d, and e are brightness at a predetermined measurement point (one central portion of each region) of the A region, B region, C region, D region, and E region).

?:? L ^* < 1.0

?: 1.0?? L ^* ? 2.0

×: ΔL ^* > 2.0

(6) Durability of Polarizer with Adhesive Layer (15 inch size)

("1737" manufactured by Corning Incorporated, Corning Incorporated) after the polarizing plate with a pressure-sensitive adhesive layer was adjusted to a size of 233 mm × 309 mm by a cutting device (Super Cutter "PN1-600" available from Oginose Ikisei Co., , The mixture was pressed under the conditions of 0.5 MPa and 50 캜 for 20 minutes with an autoclave made by Kurihara Seisakusho Co., Ltd. Thereafter, the sample was placed under the conditions of the following durability conditions, and after 200 hours, observation was carried out using a 10 magnification loupe, and the durability was evaluated according to the following criteria.

O: No defects (lifting, peeling, foaming, etc.) are present at a position of 0.3 mm or more from the end.

?: There is a defect at a position of 0.3 to 0.7 mm from the end. There is no defect at positions exceeding 0.7 mm from the ends.

X: There is a defect at a position of 0.7 mm or more from the end.

&Lt; Durability condition &

60 ℃ · Relative humidity 90% RH Environment, 80 ℃ Dry environment

A heat shock test of 30 minutes each at -35 DEG C to 70 DEG C,

Example  1 to 9 and Comparative Example  1 to 6

A pressure-sensitive adhesive formulation material having the composition shown in Table 1 (in terms of solid content) was prepared and toluene was added as a solvent to obtain a coating liquid having a solid content adjusted to 20 mass%. The coating solution was applied on a release layer of a 38 占 퐉 -thick polyethylene terephthalate release film (SP-PET3811, product of Lintel Co.) as a release film so that the thickness after drying was 20 占 퐉, , And then dried at 90 DEG C for 1 minute to form a pressure-sensitive adhesive-forming material layer.

Subsequently, a polarizing plate made of a polarizing film with a disk-shaped liquid crystal layer (viewing angle increasing function layer) was bonded such that the pressure-sensitive adhesive agent-forming material layer and the disk-shaped liquid crystal layer were in contact with each other. After 30 minutes from bonding, ultraviolet rays (UV) were irradiated from the side of the release film under the following conditions to prepare a polarizing plate with a pressure-sensitive adhesive layer. The thickness of the pressure-sensitive adhesive layer was 25 m.

<UV irradiation condition>

· Electrodeless lamp H valve is used by FUJON Co.

Light intensity: 600 mW / cm 2, light quantity: 150 mJ / cm 2

[UVPF-36, manufactured by Eyegraphics Co., Ltd.] was used as the UV illuminance / light amount meter.

Table 2 shows the performance of the pressure-sensitive adhesive, the performance of the polarizing plate with a pressure-sensitive adhesive layer, and the evaluation results of the non-sticking property of the antistatic agent.

In addition, instead of bonding the pressure-sensitive adhesive material layer of Example 1 to the polarizing plate, another polyethylene terephthalate release film ("SP-PET3801" manufactured by Lin TEX Co., Ltd.) was bonded.

Thereafter, ultraviolet rays were irradiated under the same conditions as in the case of bonding to the polarizing plate to obtain an optical pressure-sensitive adhesive sheet having a constitution of a release film / pressure-sensitive adhesive layer / release film.

Subsequently, the release film ("SP-PET3801" manufactured by LIN TEX Co., Ltd.) was peeled off, and the surface of the exposed pressure-sensitive adhesive layer and the surface of the polarizing plate bonded to the pressure-sensitive adhesive layer were subjected to corona treatment and then they were joined together to obtain a polarizer with a pressure- .

The resulting polarizer with a pressure-sensitive adhesive layer had the same performance as the polarizer with a pressure-sensitive adhesive layer of Example 1.

The numerical values of (a-1), (a-2), (a-3) and other columns show the content (mass%) of each component (constituent unit) in the acrylic acid ester copolymer (A) The numerical values in the columns (b-1) and (b-2) represent the content (mass%) of each component (constituent unit) in the acrylic acid ester copolymer (B).

The weight average molecular weights (Mw) of the acrylic acid ester copolymers (A) and (B) were all 1.4 million. The measurement conditions are as follows.

&Lt; GPC measurement condition >

GPC measurement apparatus: "HLC-8020" manufactured by Tosoh Corporation

GPC column (Pass in the following order): Toso Co., Ltd.

TSK, guard column "HXL-H"

TSK ge1 "GMHXL" (× 2)

TSK gel "G2000HXL"

Measurement solvent: tetrahydrofuran

Calibration curve: polystyrene

Measuring temperature: 40 ° C

INDUSTRIAL APPLICABILITY The optical pressure-sensitive adhesive of the present invention is a pressure-sensitive adhesive for optical use which has an antistatic property and is excellent in adhesive strength, re-releasability (durability) and durability, which is used when an optical member such as a polarizing plate is laminated on an adherend, And also is suitable for attaching an optical member such as a polarizing plate.

1: polyvinyl alcohol polarizer 2: TAC film I
2 ': TAC film II 3: pressure-sensitive adhesive layer
4: peeling sheet 5: surface protective film
10: polarizer

Claims (10)

(Meth) acrylate monomer having an oxyalkylene group in which the oxyalkylene group has 2 to 4 carbon atoms and the number of oxyalkylene groups is 1 to 10, (a-1) 2) less than 10% by mass of a reactive group-containing (meth) acrylic monomer, (a-3) a (meth) acrylic acid ester copolymer having a (meth) acrylic acid alkyl ester as a constituent unit; (B) a (meth) acrylic acid ester copolymer having a reactive group-containing (meth) acrylic monomer as a constituent unit; (C) an active energy ray-curable compound, and (D) an antistatic agent and the content ratio of the component (A) and the component (B) is from 100: 1 to 100: By weight of the pressure-sensitive adhesive for optical use. The optical pressure-sensitive adhesive according to claim 1, wherein the content of the active energy ray-curable compound (C) is 1 to 50 parts by mass based on 100 parts by mass of the total amount of the component (A) and the component (B). delete The optical pressure-sensitive adhesive according to any one of claims 1 to 3, wherein (a-2) the reactive group-containing (meth) acrylic monomer is a hydroxyl group-containing (meth) acrylic monomer. The optical adhesive according to any one of claims 1 to 3, wherein the (meth) acrylic monomer containing a reactive group as a constituent unit of the component (B) is a carboxyl group-containing (meth) acrylic monomer. The positive resist composition according to claim 1 or 2, wherein the content of the antistatic agent (D) is 0.1 to 10 parts by mass relative to 100 parts by mass of the total amount of the component (A), the component (B) Pressure sensitive adhesive. The optical adhesive according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive material further comprises (E) a crosslinking agent. A pressure-sensitive adhesive sheet for optical with a release film formed by using the optical pressure-sensitive adhesive according to claim 1 or 2. An optical member with a pressure-sensitive adhesive layer having a layer made of the optical pressure-sensitive adhesive according to claim 1 or 2, on an optical member. The optical member with a pressure-sensitive adhesive layer according to claim 9, wherein the optical member is a polarizing plate.

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