KR20170062363A - Adhesive composition, adhesive film and image display device - Google Patents

Abstract

[PROBLEMS] To provide a pressure-sensitive adhesive composition which has excellent adhesive force and excellent balance of bending resistance which is hardly peeled or peeled off even when bending is carried out over a temperature range where use is assumed.
[MEANS FOR SOLVING PROBLEMS] A thermoplastic resin composition comprising 100 parts by mass of a main component (A) comprising a curable compound, 0 to 5 parts by mass of a terpene phenolic tackifier (B) having a softening point of 130 ° C or more and 0.01 part by mass By mass to 5 parts by mass or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pressure-sensitive adhesive composition,

The present invention relates to a pressure-sensitive adhesive composition suitable for use in a flexible device, and an adhesive film and an image display device obtained by curing the pressure-sensitive adhesive composition.

At present, flat panel display panels such as liquid crystal display panel (LCD) and plasma display panel (PDP) are mainly used as display panels. On the surface of the planar display panel, a laminate in which a plurality of films are laminated is usually adhered. For example, in an LCD, an optical film such as a polarizing plate, a retardation plate, a viewing angle enlarging film, and a brightness improving film is laminated on the surface of a liquid crystal panel. Each layer constituting the planar display panel is usually bonded by an adhesive layer formed of various kinds of pressure-sensitive adhesives.

On the other hand, in recent years, a curved surface display or a flexible display has been demanded in addition to a planar display, from a variety of design characteristics and usage methods. An organic electroluminescence panel (OLED) is mainly used for a curved display or a flexible display.

The optical film laminate laminated by the pressure-sensitive adhesive film or the adhesive layer used in the curved display or the flexible display has excellent adhesion and bending property in addition to optical characteristics and durability, It is required that nothing happens.

As an adhesive film used for a conventional optical film laminate (optical member) for a planar display panel, for example, Patent Document 1 discloses an adhesive film comprising a (meth) acrylic acid alkyl group having 2 to 18 carbon atoms in the form of a linear or branched alkyl group An acrylic polymer having a weight average molecular weight of 30 to 2,500,000 and having a monomer unit of ester as a main skeleton and a copolymerizable monomer copolymerized with the alkyl (meth) acrylate as a monomer unit, as a base polymer, And a transition temperature (Tg) of -35 占 폚 or less.

(Prior art document)

(Patent Document 1) JP2011-017009 A

However, in the technique of Patent Document 1, since the modulus of elasticity is not suitable, it is impossible to bend at a low temperature such as -20 占 폚 or at a high temperature such as 60 占 폚, or the adhesive strength is not sufficient, There was a problem that peeling or peeling occurred in the surface of the substrate.

Therefore, an object of the present invention is to provide a pressure-sensitive adhesive composition which has excellent adhesive force and excellent balance of bending resistance which is hardly peeled off or peeling off even when bending is carried out over a temperature range where use is assumed.

The present inventors have conducted intensive researches to solve the above problems. As a result, 100 parts by mass of a main component (A) comprising a curable compound, 0 parts by mass or more and less than 5 parts by mass of a terpene phenolic tackifier (B) having a softening point of 130 ° C or more, and 0.01 parts by mass of a photopolymerization initiator And not more than 5 parts by mass based on the total weight of the pressure-sensitive adhesive composition. The present invention has been accomplished based on this finding.

According to the present invention, it is possible to provide a pressure-sensitive adhesive composition having excellent adhesive force and excellent balance of bending resistance, which is hardly peeled or peeled off even when bending is performed, over the entire temperature range where use is assumed. The pressure-sensitive adhesive composition according to the present invention is particularly suitable for flexible display applications. The pressure-sensitive adhesive composition according to the present invention has a low rate of resistance change and can be used in a display without corroding a metal film or a metal coating layer.

Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments.

In this specification, unless otherwise stated, the measurement of operation and physical properties is performed at room temperature (20 ° C or more and 25 ° C or less) / relative humidity of 40% RH or more and 50% RH or less.

[Pressure sensitive adhesive composition]

The pressure-sensitive adhesive composition of the present invention (hereinafter also simply referred to as "composition") comprises 100 parts by mass of a main component (A) comprising a curable compound and 0 to 5 parts by mass of a terpene- phenolic tackifier (B) having a softening point of 130 ° C or higher By mass, and the photopolymerization initiator (D) in an amount of 0.01 to 5 parts by mass. By having such a constitution, the pressure-sensitive adhesive composition of the present invention is excellent in adhesive strength and bending strength over a wide temperature range (for example, from -20 캜 to 80 캜, preferably from -20 캜 to 60 캜) It is possible to obtain the effect that the balance of the bending tolerance which is hard to occur even if the peeling is removed.

The pressure-sensitive adhesive used in the bendable image display device is required to withstand deformation due to bending in the entire temperature range to be used in addition to deformation caused by stress in the conventional image display apparatus which can not be bent.

As a result of intensive research conducted by the inventors of the present invention, it has been found that when 100 parts by mass of a main component (A) comprising a curable compound and from 0 to 5 parts by mass of a terpene phenolic tackifier (B) , And a photopolymerization initiator (D) in an amount of not less than 0.01 parts by mass and not more than 5 parts by mass, solves the above problems.

For some reason, the details of whether the above-mentioned effect can be obtained by the pressure-sensitive adhesive composition of the present invention are unclear, but are considered as follows. That is, when the softening point is lower than 130 占 폚, the cohesive strength at high temperature is not sufficiently obtained, and therefore, when the softening point is flexed at high temperature, the bonding portion is broken due to the flow of the pressure sensitive adhesive . In the tackifier other than the terpene phenol compound, a tackifier and a main component (for example, a (meth) acrylic acid ester monomer (a -1), etc.) can not be ensured. On the other hand, the taperphenolic tackifier has a high polarity and also has a suitable compatibility with the main component. Among them, it is considered that it is possible to have an adhesive force required for the pressure-sensitive adhesive composition and flexibility at high temperature and low temperature by containing a tackifier-phenol-based tackifier having a high softening point. If the amount of the tackifier in the pressure-sensitive adhesive composition is 5 parts by mass or more based on 100 parts by mass of the main component (A), the adhesive strength of the cured adhesive film is lowered, and furthermore, It is difficult to obtain a satisfactory bending resistance in a wide temperature range (for example, -20 DEG C to 80 DEG C) because the elastic modulus is lowered and the storage elastic modulus is increased at a low temperature (for example, -20 DEG C) . When the amount of the cross-linking agent (C) is more than 1 part by mass, the adhesive strength is lowered, and it becomes difficult to obtain satisfactory bending resistance in a wide temperature range (for example, -20 ° C to 80 ° C).

In addition, the above mechanism is based on speculation, and the present invention is not limited to this mechanism.

The pressure-sensitive adhesive composition of the present invention preferably has a storage elastic modulus G '(80) at 80 ° C after curing of 1 x 10 ⁴ Pa or more and 5 x 10 ⁴ Pa or less in view of bending resistance at a high temperature, ^And more preferably ⁴ Pa or more and 2.5 x 10 < ⁴ > Pa or less.

The pressure-sensitive adhesive composition of the present invention preferably has a storage elastic modulus G '(-20) at -20 캜 after curing of 0.5 10 ⁵ Pa or more and 1 10 ⁶ Pa or less in view of bending resistance at low temperature, × 10 or more ⁵ ㎩ 3.5 × 10 ⁵ ㎩ below and more preferably, 1.6 × 10 ⁵ ㎩ is preferably more than or less than 3 × 10 ⁵ ㎩.

The values of the storage moduli G '(80) and G' (- 20) measured by the methods described in the examples are employed. The storage moduli G '(80) and G' (-20) can be controlled by the composition of the main component (A), the composition of the copolymer (a-3) described below, the kind and amount of the crosslinking agent (C)

The glass transition temperature of the pressure-sensitive adhesive composition of the present invention after curing is preferably -50 캜 or lower. With this range, bending resistance at high temperature and low temperature is more excellent. The glass transition temperature is more preferably -70 DEG C to -50 DEG C, -70 DEG C to -55 DEG C, more preferably -65 DEG C to -55 DEG C, and -70 DEG C to -60 DEG C . The glass transition temperature after curing can be measured by the method described in Examples. (Meth) acrylic ester monomer (a-1) (hereinafter referred to simply as "(a-1)") having a low glass transition temperature of the homopolymer (homopolymer) is required to have a glass transition temperature after curing of the pressure- (Meth) acryl monomer (a-2-1)) having a relatively high glass transition temperature of the homopolymer is appropriately adjusted (hereinafter referred to as " component (a-2) Or a monomer to be used in consideration of the glass transition temperature of the homopolymer may be appropriately selected.

Hereinafter, each component of the pressure-sensitive adhesive composition of the present invention will be described in more detail.

In the present specification, the term "(meth) acrylic acid ester monomer" is a collective term for an acrylic acid ester monomer and a methacrylic acid ester monomer. (Meth) acrylic acid (meth) acrylic acid and the like are also collectively referred to as a compound having "meta" and a compound having no "meta" in the name. For this reason, the term " (meth) acrylic " includes both acrylic and methacrylic. The "(meth) acrylic acid ester monomer" includes both an acrylic acid ester monomer and a methacrylic acid ester monomer. The term "(meth) acrylic acid" includes both acrylic acid and methacrylic acid. The "pressure-sensitive adhesive composition" is also simply referred to as "pressure-sensitive adhesive".

[Main component (A)]

The main component (A) used in the present invention is composed of a curable compound. Examples of the curable compound include (meth) acryloyl group, vinyl group, allyl group, propenyl group, dithiocarbamate group, diazo group, diazo group, A polyester resin, a polyether resin, a polyurethane resin or an epoxy resin including a polymerizable functional group such as a cinnamylidene group and / or a cinnamoyl group, and combinations thereof.

As a preferred form of the main component (A) comprising the curable compound according to the present invention,

(Hereinafter referred to simply as " component (a-2) ") which is copolymerizable with the component (a-1) of the (meth) acrylic acid ester monomer ,

(2) a copolymer (a-2) containing a structural unit derived from the component (a-1), the component (a- 3) (hereinafter, also simply referred to as copolymer (a-3)) (the form in which the curable compound is composed of a monomer and a polymer and is in the form of a polymer syrup)

(3) a form of the copolymer (a-3) (a form in which the curable compound is composed only of a polymer).

It is considered that this main component (A) is contained in the pressure-sensitive adhesive composition of the present invention, thereby securing the adhesiveness of the pressure-sensitive adhesive film obtained after curing and securing the basic characteristics.

Among them, from the viewpoints of facilitating the formation of the pressure-sensitive adhesive film according to the present invention and of exerting the desired effect of the present invention, it is preferred that the curable compound contains the copolymer (a-3) ) Or (3)) is preferable, and the form of (2) (so-called polymer syrup form) is more preferable.

< (a-1) (Meth) acrylic acid ester monomer >

The (meth) acrylic acid ester monomer (a-1) is not particularly limited as long as it is a form in which an alkyl group or a group represented by - (AO) _n -Q is introduced into the ester moiety of the (meth) acrylic acid ester. In the above "- (AO) _n -Q", A is an alkylene group, Q is an alkyl group, and n is an integer of 1 or more and 20 or less.

(A-3) containing a constitutional unit derived from a (meth) acrylic acid ester monomer (a-1) and / or a (meth) acrylic acid ester monomer (a-1) The glass transition temperature can be lowered. As a result, the bending resistance at low temperatures can be improved without lowering the adhesion.

The number of carbon atoms of the alkyl group or the group represented by - (AO) _n -Q is not particularly limited. More preferably from 2 to 18, more preferably from 3 to 16, and more preferably from 4 to 12 carbon atoms, from the viewpoint of compatibility and suppressing the glass transition temperature to a low level Particularly preferred. The ester moiety of the (meth) acrylic acid ester may be linear, branched or cyclic, but it is preferably a linear or branched chain from the viewpoint of lowering the glass transition temperature. In addition, in the case of cyclic structure, the number of carbon atoms is 3 or more.

The (meth) acrylic acid ester monomer (a-1) is typically represented by the following formula (1)

Here, in the above formula (1)

R ₁ is a hydrogen atom or a methyl group, and R ₂ is an alkyl group or a group represented by - (AO) _n -Q.

The alkyl group for R ₂ in the formula (1) is not particularly limited, and examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, isopropyl, Cyclohexyl group, 1-methylcyclohexyl group, n-heptyl group, 2-heptyl group, 3-heptyl group, 2-heptyl group, 2-heptyl group, An isohexyl group, an isononyl group, a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, an isobutyl group, an isobutyl group, an isobutyl group, A pentadecyl group, a hexadecyl group, a heptadecyl group, or an octadecyl group. Particularly, a methyl group, a butyl group, a 2-ethylhexyl group, an n-hexyl group, a nonyl group, and an isononyl group are preferable from the viewpoint of ensuring tackiness and securing basic characteristics.

Specific examples of the (meth) acrylic acid ester monomer (a-1) in which R ₂ in the formula (1) is an alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, (Meth) acrylate, isopentyl (meth) acrylate, isobutyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, heptyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl Acrylate, and lauryl (meth) acrylate. (Meth) acrylic acid ester monomer (a-1) is preferably used as the (meth) acrylic acid ester monomer (a-1) from the viewpoint of lowering the glass transition temperature and polarity after curing and securing excellent flexibility at low temperature and adhesiveness applicable to a wide range of adherends. It is particularly preferable to include hexyl (meth) acrylate.

When the group represented by - (AO) _n -Q in R ₂ of the formula (1) is an alkoxyalkyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, a propoxyethyl group, a butoxyethyl group, A methoxybutyl group, and a 2-ethylhexyloxyalkyl group (the alkyl group has 1 to 4 carbon atoms).

In the group represented by - (AO) _n -Q, A is preferably an alkylene group having 1 to 4 carbon atoms (that is, a methylene group, an ethylene group, an ethylene group, Propylene group or butylene group), more preferably 2 to 3 carbon atoms (i.e., an ethylene group or a propylene group). In this case, n is preferably an integer of 1 or more and 6 or less, more preferably an integer of 1 or more and 4 or less, and still more preferably 2 or 3. Also, Q is an alkyl group. The number of carbon atoms is preferably 1 or more and 12 or less, more preferably 2 or more and 10 or less, still more preferably 4 or more and 8 or less. Specific examples of such an alkyl group are preferably those interposed therebetween, and particularly preferable examples thereof include an n-hexyl group, a 2-hexyl group, a 3-hexyl group, a cyclohexyl group, a 1-methylcyclohexyl group, A 3-heptyl group, an isoheptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a tert-octyl group or a 2-ethylhexyl group.

Specific examples of the (meth) acrylic acid ester monomer (a-1) _wherein R ₂ in the formula (1) is a group represented by - (AO) _n -Q include methoxyethyl (meth) acrylate, ethoxymethyl Methoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxypropyl (Meth) acrylate, ethoxy-triethylene glycol (meth) acrylate, methoxy triethylene glycol (meth) acrylate, methoxy diethylene glycol (meth) acrylate, propoxy diethylene glycol (Meth) acrylate, methoxy triethylene glycol (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate, methoxypolyethylene glycol .

These (a-1) components may be used alone or in combination of two or more. The component (a-1) may be a commercially available product or a synthetic product.

AEH, AME (manufactured by Nippon Shokubai Co., Ltd.), Wright acrylate (registered trademark) EC-A, Wright acrylate (registered trademark) MTG-A, Light Acrylate (registered trademark) EHDG-AT, Light Acrylate (registered trademark) 130A, Light Acrylate (registered trademark) DPM-A (manufactured by Kyoeisha Chemical Co., 190, 2-MTA, MPE400A, MPE550A (manufactured by Osaka Organic Chemical Industry Co., Ltd.), AM-90G and AM-130G (manufactured by Shin Nakamura Kagaku Kagaku Kogyo) ) Are suitable.

(A-1) of the formula (1) wherein R ₂ is the above-mentioned alkyl group, or the monomer (a-1-1) of the formula (1) wherein R ₂ is the above- And a monomer (a-1-2) of the formula (1) wherein R ₂ is a group represented by the formula - (AO) _n -Q. The monomer (a-1-1): monomer (a-1-2) in the mixture may be contained in a weight ratio of 1: 1 to 3: 1, preferably 1: 1 to 1: 2. Within the above range, the tackiness of the pressure-sensitive adhesive film can be secured.

< (a-2) Monomer copolymerizable with the component (a-1)

The main component (A) according to the present invention preferably contains a monomer (a-2) component copolymerizable with the component (a-1). (a-2-1) an amide group-containing (meth) acrylic monomer, (a-2-2) a hydroxyl group-containing (meth) acrylic monomer, (a- 2-3) (Meth) acrylate monomers having functional groups and (a-2-4) multi-functional (meth) acrylate monomers. The (a-2-1) amide group-containing (meth) acrylic monomer, (a-2-2) hydroxyl group-containing (meth) acrylic monomer, (a- 2-3) The use of a macromonomer having a polymerizable functional group or a monomer copolymerizable with the component (a-1) other than the (a-2-4) multifunctional (meth) acrylate monomer is not excluded.

«(A-2-1) Amide group-containing (meth) acrylic monomer»

The main component (A) according to the present invention preferably contains an amide group-containing (meth) acrylic monomer (a-2-1) (hereinafter also referred to simply as a component (a-2-1)). Since the component (a-2-1) is contained in the main component (A), the following effects are obtained. That is, the amide group-containing (meth) acrylic monomer usually has a high glass transition temperature and a high polarity. Therefore, as the bulk physical properties of the pressure-sensitive adhesive, the cohesive force is improved. On the other hand, as an interface characteristic, affinity to a polar material is improved. Therefore, when the polymer contained in the adhesive film after curing contains a constituent unit derived from the component (a-2-1), adhesion and durability are improved. Such a mechanism is considered to occur similarly even when a carboxyl group-containing monomer such as acrylic acid is used, but a carboxyl group-containing monomer such as acrylic acid is metal corrosive and therefore may not be suitable depending on the use.

The amide group-containing (meth) acrylic monomer (a-2-1) is not particularly limited as long as it has an amide group in the (meth) acrylic monomer. The component (a-2-1) is typically represented by the following formula (2):

Here, in the formula (2)

R ₈ is a hydrogen atom or a methyl group,

R ₉ is a single bond or a divalent organic group,

R ₁₀ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an acyl group, an epoxy group, an alkoxy group having 1 to 6 carbon atoms or a dimethylamino group,

R ₁₁ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

The divalent organic group is not particularly limited, but an alkylene group or an acylene group having 1 to 10 carbon atoms is suitable. The alkylene group or the acyl group may have at least one alkyl group having 1 to 8 carbon atoms, a phenyl group or a cyclohexyl group as a substituent.

Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, A cyclohexyl group, a cyclohexyl group, a 1-methylcyclohexyl group, an n-heptyl group, a 2-heptyl group, a 3-heptyl group, an isoheptyl group, a tert- , A 2-ethylhexyl group, a nonyl group, an isononyl group, and a decyl group.

The carbon number of the acyl group is not particularly limited, but is preferably 1 to 18 carbon atoms, and more preferably 1 to 6 carbon atoms. In addition, an acyl group includes an acetoacetoxy group or an acetyl group.

Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy, ethoxy, propyloxy, isopropyloxy, butoxy, sec-butoxy, tert- -Hexyloxy group, 3-hexyloxy group, cyclohexyloxy group and the like are suitable.

The alkylene group having 1 to 10 carbon atoms is a divalent substituent obtained by removing one hydrogen atom of the alkyl group having 1 to 10 carbon atoms.

R ₁₀ and R ₁₁ may form a ring having 2 to 8 carbon atoms or may have an oxygen atom (i.e., an oxygen-containing heterocyclic group) or a sulfur atom (i.e., a sulfur-containing heterocyclic group) in the ring do.

(Meth) acryloyl morpholine, N, N-dimethyl (meth) acrylamide, N, N-dicyclohexyl (Meth) acrylamides such as ethyl (meth) acrylamide, diacetone (meth) acrylamide, N, N- dimethylaminopropyl (meth) acrylamide, N- (Meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide and Nt-butyl (Meth) acryloyl morpholine, N, N-dimethyl (meth) acrylamide, N, N-di Ethyl (meth) acrylamide, diacetone (meth) acrylamide, (Meth) acrylamide and the like are preferable. Further, the amide group-containing (meth) acrylic monomer (a-2-1) may be N, N-methylene bis (meth) acrylamide. These (a-2-1) components may be used alone or in combination of two or more. The component (a-2-1) may be a commercially available product or a synthetic product.

Examples of commercially available products include HEAA (registered trademark), ACMO (registered trademark), DMAPAA (registered trademark), DMAA (registered trademark), NIPAM (registered trademark), DEAA (registered trademark) , NBMA, IBMA, NMMA, TBAA, and MBAA (manufactured by MRC Unitech Co., Ltd.) and N-MAN (manufactured by MIKI RIKEN CO., LTD.) Are suitable.

«(A-2-2) Hydroxyl group-containing (meth) acrylic monomer»

The main component (A) according to the present invention may contain a hydroxyl group-containing (meth) acrylic monomer (a-2-2) (hereinafter also referred to simply as a component (a-2-2)).

The component (a-2-2) may be included as a constituent unit of the polymer contained in the adhesive film after curing. Thus, polarity is imparted to the pressure-sensitive adhesive film formed from the pressure-sensitive adhesive composition of the present invention. Therefore, when an optical member having a high polarity such as a polarizing plate is used as an adherend, it has the effect of improving the adhesiveness and can exhibit the desired effect of the present invention more efficiently.

The (meth) acrylic monomer containing a hydroxyl group is typically represented by the following formula (3):

Here, in the formula (3)

R ₅ is a hydrogen atom or a methyl group,

R ₆ is a divalent organic group.

Here, the divalent organic group is not particularly limited, but an alkylene group having 1 to 10 carbon atoms is suitable. Examples of the alkylene group having 1 to 10 carbon atoms include those described above. The alkylene group may have at least one alkyl group having 1 to 8 carbon atoms, a phenoxyalkyl group (the number of carbon atoms in the alkyl group is 1 to 8), a phenyl group, a phenoxy group or a cyclohexyl group as a substituent. The alkyl group having 1 to 8 carbon atoms may be appropriately selected from the above.

(Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl Phenoxypropyl (meth) acrylate, and the like. Among them, 4-hydroxybutyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate are preferable from the viewpoint of adhesiveness. These (a-2-2) components may be used alone or in combination of two or more. As the component (a-2-2), a commercially available product or a synthetic product may be used.

4HBA, CHDMMA (manufactured by NIPPON KASEI CO., LTD.), Light ester HOA (N), and light ester HOP-A (N) (commercially available from Nippon Shokubai Co., , Wright acrylate (registered trademark) HOB-A (manufactured by Kyoeisha Chemical Co., Ltd.), and the like are suitable.

«(A-2-3) Polymerizable functional group-containing macromonomer»

The main component (A) according to the present invention may contain a macromonomer (a-2-3) having a polymerizable functional group (hereinafter also referred to as a component (a-2-3)). The component (a-2-3) is a high molecular weight monomer having a polymerizable functional group (unsaturated group), and is composed of a polymer chain portion and a polymerizable functional group portion.

The polymer (cured) obtained by using such a monomer is included in the adhesive film, so that the bending resistance (bending resistance) is improved. The mechanism is considered to be different depending on the glass transition temperature of the polymer chain portion of the macromonomer. Concretely, when the glass transition temperature of the polymer chain portion is high, the polymer chain portion forms a hard segment in the pressure-sensitive adhesive film, so that a cohesive force is generated in the pressure-sensitive adhesive film. By this, it is considered that the adhesive force to the substrate is improved and the bending resistance is improved. In addition, when the glass transition temperature of the polymer chain portion of the macromonomer is low, the pressure-sensitive adhesive film becomes soft and the followability to the substrate increases, thereby improving the bending resistance. In addition, the above mechanism is based on speculation, and the present invention is not limited to this mechanism.

As the polymerizable functional group of the component (a-2-3), a group having an ethylenically unsaturated double bond (ethylenic unsaturated group) is preferable. Specifically, it is preferably at least one selected from the group consisting of a vinyl group, an allyl group, a (meth) acryloyl group, and a propenyl group. The polymerizable group is preferably present at the end of the macromonomer and more preferably from one end of the macromonomer in terms of stability at the time of polymerization. However, the polymerizable group may be present as a side chain of the macromonomer or may be present at both ends of the chain of the macromonomer.

(meth) acrylate, n-butyl (meth) acrylate, stearyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, t-butyl (meth) acrylate, styrene, acrylonitrile, hydroxy (meth) acrylate, ethylhexyl (Co) polymer is preferable. These polymer chain portions may be composed of a single repeating unit or a plurality of repeating units. When the polymer chain is a copolymer comprising a plurality of repeating units, the repeating form thereof is not limited, and may be any of an alternating copolymer, a random copolymer, and a block copolymer.

The component (a-2-3) is typically represented by the following formula (4):

In the formula (4), R ₁₂ represents a hydrogen atom or a methyl group, and X ₁ represents a single bond or a divalent linking group.

Examples of the divalent linking group include straight-chain, branched or cyclic alkylene groups, aralkylene groups, and arylene groups. These may further have a substituent such as a hydroxyl group or a cyano group. The number of carbon atoms of the alkylene group is preferably 1 or more and 10 or less, and more preferably 1 or more and 4 or less. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group and a decylene group. Among them, a methylene group, an ethylene group, a propylene group and the like are preferable. The number of carbon atoms of the aralkylene group is preferably 7 or more and 13 or less. Examples of the aralkylene group include a benzylidene group and a cinnamylidene group. The number of carbon atoms of the arylene group is preferably 6 or more and 12 or less. Examples of the arylene group include a phenylene group, a cumeneylene group, a mesitylenylene group, a tolylene group and a xylylenylene group. Among them, a phenylene group is preferable.

Among the divalent linking groups, the groups represented by -NR ₂ -, -COO-, -OCO-, -O-, -S-, -SO ₂ NH-, -NHSO ₂ -, -NHCOO-, -OCONH- or heterocyclic A group to be introduced may be interposed as a coupler. R ₂ is a hydrogen atom or an alkyl group such as a methyl group, an ethyl group or a propyl group.

In the above formula (4), X ₂ is preferably a methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, stearyl (meth) (Meth) acrylate, t-butyl (meth) acrylate, styrene, and (meth) acrylonitrile, or a polymer obtained by homopolymerizing or copolymerizing one or more monomers selected from Organosiloxane). Among them, X ₂ is preferably a polymer obtained by homopolymerizing methyl (meth) acrylate, styrene, n-butyl (meth) acrylate or isobutyl (meth) acrylate, a (meth) acrylonitrile and styrene Or a polyorganosiloxane. From the viewpoint of durability at a high temperature, X ₂ is preferably a polymer obtained by homopolymerizing methyl (meth) acrylate, styrene and isobutyl (meth) acrylate or copolymerizing (meth) acrylonitrile and styrene Is particularly preferred. Or from the viewpoint of bending resistance at low temperature, X ₂ is preferably a polyorganosiloxane, and particularly preferably a polydimethylsiloxane. In addition, as long as the performance of the pressure-sensitive adhesive is not affected, a part of the methyl group of the polydimethylsiloxane may be replaced by a hydrogen atom or an organic group other than the methyl group (ethyl group, phenyl group, etc.).

The above polydimethylsiloxane can be obtained by hydrolysis and condensation of dimethyldialkoxysilane such as dimethyldimethoxysilane and dimethyldiethoxysilane. At this time, an organic group other than a methyl group can be introduced into the polydimethylsiloxane by using an alkoxysilane having an organic group other than the methyl group (for example, diethyldiethoxysilane or the like) in combination. In addition to the dialkoxy silane compound, a small amount of a trialkoxy silane compound may be added.

The number average molecular weight (Mn) of the component (a-2-3) is preferably in the range of 2000 to 20000, more preferably in the range of 2000 to 10000, more preferably in the range of 4000 to 8000 Is more preferable. If the number average molecular weight (Mn) is 2000 or more, the performance of the pressure-sensitive adhesive can be improved even when the amount of the component (a-2-3) added in the copolymer (a-3) is small. On the other hand, if it is 20,000 or less, the viscosity of the pressure-sensitive adhesive is low and workability is good. The value of the number average molecular weight (Mn) can be controlled by appropriately selecting the amounts of chain transfer agent and polymerization initiator to be added to the polymerization system. In the present invention, the number average molecular weight (Mn) of the macromonomer should be a value in terms of polystyrene measured by GPC (gel permeation chromatography).

The component (a-2-3) may be a commercially available product or a synthetic product. When the component (a-2-3) is synthesized, the synthesis method is not particularly limited. For example, (1) a polymer chain (living polymer anion) constituting a macromonomer by living anionic polymerization is prepared, Methacrylic acid chloride or the like; (2) a method in which a radical polymerizable monomer such as methyl methacrylate is polymerized in the presence of a chain transfer agent such as mercaptoacetic acid to obtain an oligomer having a carboxyl group at the terminal and then reacted with glycidyl methacrylate or the like; (3) polymerizing a radically polymerizable monomer such as methyl methacrylate in the presence of an azo-based polymerization initiator containing a carboxyl group to obtain an oligomer having a carboxyl group at the terminal thereof, followed by macromonomerization with glycidyl methacrylate Method can be used.

By producing the macromonomer using the above-described method, for example, the following groups are introduced as the divalent linking group represented by X ₁ in the formula (4).

(product name: 45% AA-6 (AA-6S (trade name)) having a terminal methacryl group and a polymer chain portion of polymethyl methacrylate (PMMA) (Product name: AS-6S, AS-6, manufactured by TOAGOSEI CO., LTD.) In which the polymer chain portion is polystyrene, the polymer chain portion is styrene / (Trade name: AN-6S; manufactured by Toagosei Co., Ltd.), which is a copolymer of acrylonitrile, a macromonomer of polybutyl acrylate (product name: AB-6, manufactured by Toagosei Co., Ltd.) (Trade name: AW-6S; manufactured by Toagosei Co., Ltd.), which is a polyisobutyl methacrylate, and a macromonomer (product name: AK-5, manufactured by TOAGOSEI CO., LTD.) In which the polymer chain portion is a polydimethylsiloxane have. These macromonomers may be used alone or in combination of two or more.

«(A-2-4) Multifunctional (meth) acrylate monomer»

The main component (A) according to the present invention may contain a polyfunctional (meth) acrylate monomer (a-2-4) (hereinafter also referred to as a component (a-2-4)). The component (a-2-4) is a monomer having two or more (meth) acryloyl groups in the molecule.

By containing the above-mentioned compound as the main component (A), the adhesive force of the adhesive film formed by curing the pressure-sensitive adhesive composition according to the present invention can be improved. This is presumably because the polyfunctional (meth) acrylate monomer forms a three-dimensional network in the adhesive film.

The (meth) acryloyl group contained in the polyfunctional (meth) acrylate monomer may be bifunctional, trifunctional or tetrafunctional.

Specific examples of the bifunctional (a-2-4) component include 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) (Meth) acrylate, hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, tricyclodecane dimethanol di (Meth) acrylate, alkoxylated di (meth) acrylate, alkoxylated di (meth) acrylate, alkoxylated cyclohexanedimethanol di (meth) acrylate, alkoxylated di (Meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, diethylene glycol di (Meth) acrylate, glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di .

Specific examples of the trifunctional (a-2-4) component include isocyanuric acid tri (meth) acrylate, ε-caprolactone modified tris- (2- (meth) acryloxyethyl) isocyanurate (Meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropaneethoxytri (meth) acrylate, and alkylene oxide adducts thereof.

More specifically, examples of the component (a-2-4) below include tetramethylolpropane tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate, and alkylene oxide adducts thereof.

In addition to the above, polyester poly (meth) acrylate and epoxy (meth) acrylate having two or more (meth) acrylate groups at the terminals may be used.

Among them, from the viewpoint of improvement of the adhesive strength, it is preferable to use at least one member selected from the group consisting of ditrimethylolpropane tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (Meth) acrylate, or dipentaerythritol hexa (meth) acrylate, are more preferable.

&Quot; Content of each component in the above (1) form &quot;

The content of the component (a-1) is preferably 50% by mass or more and 99.9% by mass or less, based on 100% by mass of the amount of the main component (A) (the total amount of the component (a- desirable. When the content is 50% by mass or more, the storage elastic modulus at -20 캜 is lowered, the bending resistance at low temperatures is excellent, and the adhesive strength is improved. On the other hand, if it is 99.9 mass% or less, various durability is excellent. The content of the component (a-1) is preferably 75% by mass or more and 99.9% by mass or less, more preferably 79% by mass or more but less than 98.5% by mass from the viewpoint of securing the adhesive strength while lowering the glass transition temperature of the pressure- , And not less than 80 mass% and not more than 95 mass%.

The content of the component (a-1-1) is 30% by mass or more and 99.9% by mass or less, preferably 40% by mass or more and 99.9% by mass or less and 40% by mass or more by mass with the amount of the main component (A) being 100% 90 mass% or less, and 40 mass% or more and 85 mass% or less. Within the above range, flexibility at low temperatures can be ensured without deteriorating tackiness.

The content of the component (a-1-2) is 0 mass% or more and 50 mass% or less, preferably 0.1 mass% or more and 50 mass% or less and 5 mass% or more 50 mass% or less, 10 mass% or more and 50 mass% or less, 20 mass% or more and 50 mass% or less, 30 mass% or more and 50 mass% or less, or 30 mass% or more and 40 mass% or less. Within the above range, flexibility at low temperatures can be ensured without deteriorating tackiness.

The content of the component (a-2-1) is preferably 0 mass% or more and 25 mass% or less, with the amount of the main component (A) being 100 mass%. More preferably, it is 0.5 mass% or more and 20 mass% or less, 0.5 mass% or more and 10 mass% or less, or 0.5 mass% or more and 5 mass% or less from the viewpoints of adhesion improvement and durability. Within the above range, adhesive strength and durability can be good.

The content of the component (a-2-2) is preferably 0.1% by mass or more and 50% by mass or less, with the amount of the main component (A) being 100% by mass. The content of the component (a-2-2) is more preferably 0.5% by mass or more and 20% by mass or less from the viewpoint of securing an amount of the component (a-1) More preferably 4 mass% or more and 20 mass% or less, and 10 mass% or more and 20 mass% or less. Within the above range, there may be an effect of improving adhesion.

The content of the component (a-2-3) is preferably 0 mass% or more and 25 mass% or less, with the amount of the main component (A) being 100 mass%. When the content is within this range, the bending resistance (bending resistance) is excellent. More preferably, it is 0 mass% or more and 10 mass% or less, 0.5 mass% or more and 10 mass% or less, or 0.5 mass% or more and 5 mass% or less from the viewpoints of improvement in adhesion and durability. Within the above range, adhesiveness and durability can be improved.

The content of the component (a-2-4) is preferably 0 mass% or more and 1 mass% or less, with the amount of the main component (A) being 100 mass%. When the content of the component (a-2-4) is set at 1% by mass or less, the adhesive force can be secured while lowering the glass transition temperature after curing of the pressure-sensitive adhesive composition. The content of the component (a-2-4) is more preferably from 0 mass% to 0.5 mass%, further preferably from 0.01 mass% to 0.1 mass%, from the viewpoint of balance between the glass transition temperature and the adhesive force after curing % Or less. Within the above range, the glass transition temperature after curing can secure the range of the present invention, and the adhesive strength is good.

The content of the component (a-2) is 0.1% by mass or more and 50% by mass or less with respect to 100% by mass of the amount of the main component (A) (the total amount of the component (a- desirable. When it is 0.1% by mass or more, the storage elastic modulus at -20 캜 is low, the bending resistance at low temperature is excellent, and the adhesive strength is improved. On the other hand, if it is 50 mass% or less, various durability is excellent. The content of the component (a-2) is preferably from 0.1 mass% to 25 mass%, more preferably from 1.5 mass% to less than 21 mass% from the viewpoint of securing an adhesive strength while lowering the glass transition temperature of the pressure- , And not less than 5 mass% and not more than 20 mass%.

&Quot; Form (2) &quot;

(A-1), (a-2) and (a-1) and a constituent unit derived from the (a-2) (A form in which the curable compound is composed of a monomer and a polymer) including the copolymer (a-3) (hereinafter also simply referred to as copolymer (a-3)). (A-3) and the component (a-2) which are unreacted raw monomers among the raw monomers of the copolymer (a-3) Called polymer syrup.

The preferable content of the component (a-1) and the component (a-2) in the form of the component (2) is the same as the content of the component The description is omitted here.

The suitable content of each constituent unit of the copolymer (a-3) contained in the form of (2) is preferably within the range of the content of each component (( (a-1) component and (a-2) component) is applied as it is.

That is, the copolymer (a-3) contained in the form of (2) is a copolymer comprising 50% by mass or more and 99.9% by mass or less of the constitutional unit derived from the (meth) acrylic acid ester monomer (a- From 0 mass% to 25 mass% of constitutional units derived from the acrylic monomer (a-2-1), 0.1 mass% or more and 50 mass% or less from the constitutional unit derived from the hydroxyl group-containing (meth) acrylic monomer (a- , 0 mass% or more and 25 mass% or less of the constitutional unit derived from the macromonomer (a-2-3) having a polymerizable functional group and 0 mass or less of the constitutional unit derived from the polyfunctional (meth) acrylate monomer (a-2-4) (A-2), (a-2-2), (a-2-3) and (a-2-4) ) Component is 100% by mass). (Meth) acrylic acid ester monomer (a-1), more preferably not less than 75 mass% and not more than 99.9 mass%, or not more than 79 mass% , More than 98.5% by mass, and not less than 80% by mass and not more than 95% by mass. (A-2-1) derived from an amide group-containing (meth) acrylic monomer (a-2-1) in an amount of not less than 0.5% by mass and not more than 10% by mass , And 0.5% by mass or more and 5% by mass or less. (Meth) acrylic monomer (a-2-2), more preferably from 0.5% by mass or more to 20% by mass or less of the constituent unit derived from the hydroxyl group-containing (meth) acrylic monomer (a- , Not less than 4 mass% and not more than 20 mass%, and not less than 10 mass% and not more than 20 mass%. (A-3) having a polymerizable functional group in an amount of not less than 0.5% by mass and not more than 10% by mass of a constitutional unit derived from a macromonomer (a-2-3) having a polymerizable functional group, 0.5% by mass or more and 5% by mass or less. (Meth) acrylate monomer (a-2-4) in an amount of more than 0% by mass and not more than 0.5% by mass in the copolymer (a-3) contained in the form of the polyfunctional (meth) . However, the content of the structural unit derived from the component (a-1), the component (a-2-1), the component (a-2-2), the component (a- 2-3) The total amount is 100% by mass.

The content of the copolymer (a-3) relative to the total amount (total mass) of the main component (A) in the form of the copolymer (2) is preferably 1% by mass or more, Or more and 20 mass% or less, and more preferably 5 mass% or more and 15 mass% or less. The content of the copolymer (a-3) can be controlled, for example, by controlling the polymerization rate in the bulk polymerization method using a photopolymerization initiator described later, or by adjusting the content of the component (a-1) Or by further adding them.

(Mw) of the copolymer (a-3) in the form of the copolymer (2) is preferably not less than 1,000,000 and not more than 3.5 million, and more preferably not less than 1.2 million and not more than 3.2 million. When the weight-average molecular weight is 1 million or more, the durability and the occurrence of peeling and peeling are suppressed, and the adhesion is improved. If it is less than 3.5 million, the viscosity of the copolymer solution becomes appropriate, and workability such as coatability is improved. The glass transition temperature of the copolymer (a-3) is preferably -50 캜 or lower. With this range, bending resistance at high temperature and low temperature is more excellent. The glass transition temperature is more preferably -70 DEG C or higher to -43 DEG C or lower, and still more preferably -65 DEG C or higher or -55 DEG C or lower.

(A-1) and (a-2) relative to the total amount (total mass) of the main component (A) in the form of the pressure-sensitive adhesive composition (2) , It is 80 mass% or more and 99 mass% or less, and more preferably 85 mass% or more and 95 mass% or less.

&Quot; Form (3) &quot;

As a form according to the present invention, there can be mentioned a form in which the main component (A) is composed of the copolymer (a-3) (the form in which the curable compound consists solely of a polymer).

A suitable content of each constituent unit of the copolymer (a-3) contained in the form of the component (3) is not particularly limited as long as the content of each component described in the section &quot; content of each component in the form of (1) (the component (a-1) and the component (a-2)) is applied as it is.

[Production of copolymer (a-3)] [

The method for producing the copolymer (a-3) which can be contained in the main component (A) in the form of the above (2) or (3) is not particularly limited, and a solution polymerization method using a polymerization initiator, Known methods such as an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, a thin film polymerization method and a spray polymerization method can be used. Examples of polymerization control methods include an adiabatic polymerization method, a temperature control polymerization method, and an isothermal polymerization method. As the polymerization initiator, any of a thermal polymerization initiator and a photopolymerization initiator may be used. In addition to or in addition to the method of initiating polymerization by a polymerization initiator, a method of initiating polymerization by irradiating active energy rays such as radiation, electron beam, and ultraviolet ray may be employed. Among them, the solution polymerization method using a thermal polymerization initiator or the bulk polymerization method using a photopolymerization initiator is more preferable since the molecular weight can be easily controlled and impurities can also be reduced.

As a solution polymerization method using a thermal polymerization initiator, for example, ethyl acetate, toluene, methyl ethyl ketone or the like is used as a solvent and the thermal polymerization initiator (a-3) is added to 100 parts by mass of the total amount of the raw monomers of the copolymer Preferably not less than 0.01 parts by mass and not more than 0.50 parts by mass, and the reaction is carried out at a reaction temperature of not less than 40 ° C and not more than 90 ° C (or not less than 60 ° C and not more than 90 ° C) for not less than 3 hours and not more than 10 hours Method.

Examples of the thermal polymerization initiator include 2,2-azobisisobutyronitrile (AIBN), 2,2'-azobis (2-methylbutyronitrile), azobiscyanovaleric acid, 2 , 2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis 2-methylpropionate), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile) 2-methylpropionamido], 2,2'-azobis (N-butyl-2-methylpropionamido), 2,2'-azobis [2- (2- (2-imidazolin-2-yl) propane] disulfate dihydrate, 2,2'-azobis 2-methylpropionamidine) dihydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2'-azo Azobis (1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2 ' Azo compounds such as azobis [2-methyl-N- (2-hydroxyethyl) propionamido]; tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethyl hexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, tert- Organic peroxides such as roper oxide; Inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. These thermal polymerization initiators may be used alone or in combination of two or more. According to this method, the main component (A) comprising the copolymer (a-3) can be obtained (the form of the above (3)).

The bulk polymerization method using a photopolymerization initiator is not particularly limited. For example, the raw monomer of the copolymer (a-3) and a photopolymerization initiator are added, and the reaction initiation temperature is adjusted to 20 ° C or higher and 28 ° C or lower And the active energy ray is irradiated. A method in which the reaction is stopped by introducing air into the reaction system at a stage where the temperature in the reaction system has risen from 5 ° C or more and 15 ° C or less from the reaction start temperature to obtain the copolymer (a-3). At this time, it is not necessary to react all of the raw monomers to be used, and the reaction may be stopped at the step of obtaining the desired weight average molecular weight. (A-1), (a-2) and (a-3) can be obtained by this method because the unreacted raw monomer (a- 2) component and a main component (A) (polymer syrup) containing the copolymer (a-3).

Examples of the active energy ray used in the bulk polymerization method include ultraviolet rays, laser rays, alpha rays, beta rays, gamma rays, X rays, electron beams and the like. Ultraviolet rays are suitably used. More preferably, ultraviolet light having a wavelength of 200 nm or more and 400 nm or less is used. The ultraviolet rays can be irradiated using a light source such as a high pressure mercury lamp, a microwave excitation type lamp, a chemical lamp, or a black light. The roughness is preferably in the 3.2mW / cm ² or less than 5.6mW / cm ^2.

Examples of the photopolymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1- (4- Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-hydroxy- Acetophenones such as phenylpropan-1-one; Benzophenones such as benzophenone, 4-chlorobenzophenone, 4,4'-diazobenzophenone; Benzoin ethers such as benzoin propyl ether and benzoin ethyl ether; Thioxanthones such as 4-isopropylthioxanthone; 1-hydroxycyclohexyl phenyl ketone, xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, and the like. These photopolymerization initiators may be used singly or in combination of two or more.

The photopolymerization initiator may be a commercially available product. Examples of commercially available products include commercially available products such as IRGACURE (registered trademark) 184, 819, 907, 651, 1700, 1800, 819, 369, 261, DAROCUR (Registered trademark) TPO, DAROCURE (registered trademark) 1173 (manufactured by BASF Japan Co., Ltd.), Esacure (registered trademark) KIP150, TZT (manufactured by DKSH Japan KK), KAYACURE ) BMS, DMBI (manufactured by Nippon Kayaku Co., Ltd.), and the like.

The amount of the photopolymerization initiator to be used is preferably 0.0005 parts by mass or more and 1 part by mass or less, more preferably 0.002 parts by mass or more and 0.5 parts by mass or less based on 100 parts by mass of the total amount of the raw monomers of the copolymer (a-3).

In the synthesis of the copolymer (a-3), a chain transfer agent may also be used for controlling the molecular weight. Examples of the mercapto compound include methyl mercaptan, t-butyl mercaptan, decylmercaptan, benzyl mercaptan, lauryl mercaptan, stearyl mercaptan, n-dodecylmercaptan, t-dodecylmercaptan, mercaptoacetic acid, Mercaptans such as propionic acid and its ester, 2-ethylhexyl thioglycol and octyl thioglycolate; Alcohols such as methanol, ethanol, propanol, n-butanol, isopropanol, t-butanol, hexanol, benzyl alcohol and allyl alcohol; Halogenated hydrocarbons such as chloroethane, fluoroethane and trichlorethylene; Carbonyls such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, acetaldehyde, propionaldehyde, n-butylaldehyde, furfural, benzaldehyde and the like; Methyl-4-cyclohexene-1,2-dicarboxylic acid anhydride, and alpha -methylstyrene. These may be used alone or in combination of two or more.

In the present invention, the weight average molecular weight (Mw) of the copolymer (a-3) is preferably from 1 million to 3.5 million, and more preferably from 1.2 to 3,200,000. When the weight-average molecular weight is 1 million or more, the durability and the occurrence of peeling and peeling are suppressed, and the adhesion is improved. If it is less than 3.5 million, the viscosity of the copolymer solution becomes appropriate, and workability such as coatability is improved.

In the present invention, in each of the formulas (1), (2) and (3), the content of the monomer having a carboxyl group, for example, the content of the (meth) acrylic monomer having a carboxyl group such as (meth) % To less than 0.1% by mass. By not containing the monomer having a carboxyl group in a trace amount or not at all, it is possible to prevent corrosion of a metal film such as an indium tin oxide (ITO) film or a metal coating layer, thereby lowering the resistance change rate.

[Taperphenol-based tackifier (B) having a softening point of 130 ° C or higher]

The pressure-sensitive adhesive composition according to the present invention is a pressure-sensitive adhesive composition which comprises a terpene-phenolic tackifier (B) (hereinafter, simply referred to as "component (B)") having a softening point of 130 ° C or higher with respect to 100 parts by mass of the main component And less than 5 parts by mass. As a result, it is possible to obtain a good balance between the adhesive strength and the bending resistance which is hardly peeled off even when bending is performed over the entire temperature range (for example, -20 ° C. to 80 ° C.) Effect is obtained.

If the softening point of the terpene phenolic tackifier is less than 130 캜, the adhesive portion may peel off due to bending at a high temperature, which is not preferable. The softening point of the component (B) may be 130 ° C or higher, but is preferably 140 ° C or higher, from the viewpoint of ensuring flexibility at a high temperature. The upper limit of the softening point of component (B) is not particularly limited, but is preferably 170 占 폚 or lower, and more preferably 160 占 폚 or lower, from the viewpoint of ensuring flexibility at low temperatures.

The softening point of the terpene phenolic tackifier is a value measured by a method in accordance with JIS K5902 (2006).

In the pressure-sensitive adhesive composition according to the present invention, a terphenol-based tackifier is used as a tackifier. The terpene phenolic tackifier is a tackifier having a high polarity and an appropriate compatibility with the main component (A) as compared with, for example, a rosin-based tackifier, The advantage of being flexible is obtained. In the pressure-sensitive adhesive composition according to the present invention, a terpene phenolic tackifier having a softening point of 130 ° C or higher may be a hydrogenated product or a commercially available product. Examples of such commercially available products include, but are not limited to, YS Polystar U130 (softening point 130 占 폚), YS Polystar T130 (softening point 130 占 폚), YS Polystar T145 (softening point 145 占 폚), YS Polystar T160 ), YS Polystar S145 (softening point 145 캜), YS Polystar G150 (softening point 150 캜), YS Polystar K140 (softening point 140 캜), YS Polystar TH130 (softening point 130 캜) (Yasuhara Chemical Co., (Softening point 145 ° C to 160 ° C) (Arakawa Chemical Industries Co., Ltd.), Sylvares (registered trademark) TP7042 (softening point 145 ° C) (Arizona Chemical Co.) For example. As the component (B), the above-mentioned terpene phenol-based tackifier may be used singly or in combination of two or more.

In the pressure-sensitive adhesive composition according to the present invention, the component (B) is contained in an amount of more than 0 parts by mass and less than 5 parts by mass with respect to 100 parts by mass of the main component (A). When the content of the component (B) is 5 parts by mass or more, the adhesive strength is lowered and the adhesive strength is lowered in a wide temperature range (for example, from -20 占 폚 to 80 占 폚 Or less), it is also difficult to obtain satisfactory bending resistance. The pressure-sensitive adhesive composition according to the present invention preferably contains the component (B) in an amount of 0.1 part by mass to 4 parts by mass with respect to 100 parts by mass of the main component (A) from the viewpoint of ensuring flexibility at high temperatures. More preferably 0.1 parts by mass or more and 2 parts by mass or less. Even if the crosslinking agent (C) is not contained in the above range, the adhesive strength and flexural reliability can be secured. When a plurality of (B) components are used in the pressure-sensitive adhesive composition, the compounding amount represents the total amount of the plurality of (B) components.

[Crosslinking agent (C)]

In the pressure-sensitive adhesive composition of the present invention, the content of the crosslinking agent (C) is 0 part by mass to less than 1 part by mass based on 100 parts by mass of the main component (A). However, it is preferable to further include a crosslinking agent (C) in an amount of more than 0 parts by mass and less than 1 part by mass with respect to 100 parts by mass of the main component (A) from the viewpoint of enhancing the adhesive strength. When the crosslinking agent (C) is added, the addition amount is more preferably 0.0001 part by mass or more and 0.5 part by mass or less, and still more preferably 0.002 parts by mass or more and 0.2 parts by mass or less. Within this range, there is a technical effect that both adhesion and modulus and bending resistance are compatible.

The kind of the cross-linking agent (C) that can be used in the pressure-sensitive adhesive composition of the present invention is not particularly limited, and may be an isocyanate compound, a carbodiimide compound, an oxazoline compound, an epoxy compound, a polyfunctional acrylic acid ester monomer, A coupling agent, a zirconium compound, an aluminum chelate compound and a thermal acid generator. More preferably, the cross-linking agent (C) is at least one selected from the group consisting of an isocyanate compound, a carbodiimide compound, an oxazoline compound, an epoxy compound and a peroxide, , It is more preferable that at least one of the isocyanate compound and the peroxide is used.

The cross-linking agent (C) according to the present invention may be one which forms a self-crosslinking structure (hardening agent type), does not form a cross-linking structure by itself, . Particularly, the latter are peroxides, thermal acid generators, and the like.

(Isocyanate compound)

Examples of the isocyanate compound suitably used as the crosslinking agent (C) include, but are not limited to, trimethylolpropane tolylene diisocyanate, triaryl isocyanate, diisocyanate dimer acid 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate Cyanate (4,4'-MDI), 2,4'-diphenylmethane dianisocyanate (2,4'-MDI), 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethyl xylidene diisocyanate (TMXDI), tolyldinedisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, Diisocyanate, isophoronediisocyanate (IPDI), H6-XDI (hydrogenated XDI), H12-MDI (hydrogenated MDI), hydrogenated diisocyanate Carbodiimide-modified diisocyanates of the above-mentioned diisocyanates, and isocyanurate-modified diisocyanates thereof, and the like. These may be used singly or in combination of two or more.

It may also be used in combination with a peroxide to be described later.

Adducts of the isocyanate compound and the polyol compound such as trimethylolpropane, and the biuret and isocyanurate compounds of these isocyanate compounds can also be suitably used.

The isocyanate compound may be a commercially available product or a synthetic product.

Commercially available products include, for example, CORONATE (R) L, Coronate (R) HL, Coronate (R) HX, Coronate (R) 2030, Coronate (R) TAKENATE (registered trademark) D-102, TOCANATE (registered trademark) D-110N, TOCANATE (registered trademark) D-200, TOCENATE (registered trademark) D (Registered trademark) TPA-100, DURANATE (registered trademark) TKA-100, DURANATE (registered trademark) 24A-100, ) P301-75E, Duraanate (registered trademark) E402-90T, Duraanate (registered trademark) E405-80T, Duraanate (registered trademark) TSE-100, Duraanate (registered trademark) D- ), D-201 (manufactured by Asahi Kasei Chemical Co., Ltd.), Sumidule (registered trademark) N-75, N-3200, N-3300 (manufactured by Sumika Bayer Urethane Co., And the like. Of these, Coronate L, Coronate HL, Coronate HX, Takenate D-110N, Duranate 24A-100, Dyuranate (registered trademark) TPA-100 is preferable, and Coronate (registered trademark) L, Coronate (registered trademark) HX, and Dyuranate (registered trademark) 24A-100 are more preferable.

(Carbodiimide compound)

The carbodiimide compound suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include those described in paragraphs &quot; 0039 &quot; to &quot; 0046 & One can say the formula.

(Oxazoline compound)

The oxazoline compound suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include those described in paragraph &quot; 0037 &quot; of Japanese Patent Laid-Open Publication No. 2015-087539 or those moderately modified have.

(Epoxy compound)

As the epoxy cross-linking agent (epoxy compound), any suitable epoxy cross-linking agent can be employed. For example, there may be mentioned ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neo Pentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, tetraglycidyl xylenediamine, trimethylol propane polyglycidyl ether, diglycerol polyglycidyl Polyglycerol polyglycidylether, sorbitol polyglycidylether, and the like can be used.

Examples of commercially available products include commercially available products such as TETRAD (registered trademark) C, TETRAD (registered trademark) X of Mitsubishi Kagaku Kogyo Kabushiki Kaisha, Adekaresin (registered trademark) of Adeka Co., ) EPU series, ADEKA RESIN (registered trademark) EPR series, and CELLOXIDE (registered trademark) manufactured by DAICEL CO., LTD. Particularly, liquid epoxy resins such as these are preferable in that the pressure-sensitive adhesive mixing operation when the pressure-sensitive adhesive film is produced becomes easy.

(peroxide)

The peroxide which is suitably used as the crosslinking agent (C) can be used as long as it is capable of generating radicals by heating to achieve crosslinking of the pressure-sensitive adhesive. However, considering the workability and stability, the one minute half- Or more and 160 占 폚 or less, and more preferably 90 占 폚 or more and 140 占 폚 or less. The half-life period of peroxide is an index indicating the rate of decomposition of peroxide. It is the time during which the amount of decomposition of peroxide is halved. As for the decomposition temperature for obtaining a half-life period at an arbitrary time and the half life period at an arbitrary temperature, Catalog, etc., and is described in, for example, Ninth Edition (May 2003) of Organic Peroxide Catalog published by Nippon Oil &amp;

Examples of the peroxide include bis (4-t-butylcyclohexyl) peroxydicarbonate (half-life temperature for one minute is 92.1 ° C), bis (sec-butylcyclohexyl) peroxydicarbonate Butylperoxydicarbonate (1 minute half-life temperature 92.4 占 폚), t-butyl peroxyneodecanoate (1 minute half life temperature 103.5 占 폚), t-hexyl peroxypivalate N-octanoyl peroxide (half-life temperature for one minute: 117.4 占 폚), 1,1-bis (4-hydroxyphenyl) (1 minute half life temperature 124.3 占 폚), bis (4-methylbenzoyl) peroxide (1 minute half life temperature 128.2 占 폚), dibenzoyl peroxide Half-life temperature of 130.0 占 폚), t-butyl peroxybutyrate (1 minute half-life temperature of 136.1 占 폚), and the like , Bis (4-t-butylcyclohexyl) peroxydicarbonate, diaryliodoperoxide and dibenzoyl peroxide, which are excellent in the efficiency of the crosslinking reaction, are preferably used. Particularly, bis (4-t-butylcyclohexyl) peroxydicarbonate is preferable from the viewpoint of decomposition temperature. One or more of these may be used. The isocyanate compound may be used in combination with the above-mentioned isocyanate compound.

(Titanium coupling agent)

As the titanium coupling agent suitably used as the crosslinking agent (C), there is no particular limitation, and for example, those described in paragraph &quot; 0072 &quot; of Japanese Patent Laid-Open Publication No. 2014-085616 or those moderately modified have.

(Zirconium compound)

The zirconium compound suitably used as the cross-linking agent (C) is not particularly limited, and examples thereof include those described in paragraph [0073] of Japanese Patent Laid-Open Publication No. 2014-085616 or those moderately modified .

(Aluminum chelate compound)

The aluminum chelate compound suitably used as the crosslinking agent (C) is not particularly limited, and examples thereof include those described in paragraph &quot; 0037 &quot; of Japanese Patent Laid-Open Publication No. 2008-251089 or those moderately modified have.

(Thermal acid generator)

SI-60, SI-80, SI-80L, SI-100, and SI-100L (commercially available products) can be used as the thermal acid generators, and examples thereof include hexafluoroantimonate- , San-Shin Kagakukyo Co., Ltd.) and CI-2624 (manufactured by Nippon Soda Co., Ltd.). The thermal acid generators may be used alone or in combination of two or more.

[Photopolymerization initiator (D)]

In another preferred embodiment of the present invention, the pressure-sensitive adhesive composition comprises 0.01 to 5 parts by mass of a photopolymerization initiator (D) based on 100 parts by mass of the main component (A). As a result, when the main component (A) is in the form of a polymer syrup, it is easy to form a pressure-sensitive adhesive film by performing a final copolymerization reaction. Within the above range, there may be an effect of improving adhesion and improving the transmittance. As the photopolymerization initiator (D), the above-mentioned one can be employed in the production of the copolymer (a-3). The amount of addition of these polymerization initiators is more preferably 0.025 parts by mass or more and 1 part by mass or less.

[Silane coupling agent]

The pressure-sensitive adhesive composition of the present invention may further contain a silane coupling agent from the viewpoint of improving durability.

The silane coupling agent means that it has no siloxane bond and has two or more different reactors in the molecule.

The silane coupling agent used in the pressure-sensitive adhesive composition of the present invention is not particularly limited and includes, for example, 3-glycidoxypropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxy Silane, n-propyltrimethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane, n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, phenyltri Vinyltriethoxysilane, vinyltris (? -Methoxyethoxy) silane,? -Trimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropyltriethoxysilane,? - methacryloxypropylmethyl Methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- aminopropyltrimethoxysilane, N -? - (aminoethyl) -? - aminopropyltrimethoxysilane, N -? - (aminoethyl) -? - aminopropyltri Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Chloropropyltrimethoxysilane,? -Mercaptopropyltrimethoxysilane (3- [triethoxysilyl] propyl) tetrasulfide, [gamma] -isocyanatopropyl triethoxysilane, and the like can be given. In addition, a silane coupling agent having a functional group such as an epoxy group (glycidoxy group), an amino group, a mercapto group, or a (meth) acryloyl group, a silane coupling agent containing a functional group having reactivity with these functional groups, A compound having a hydrolyzable silyl group obtained by reacting cyanate with an arbitrary ratio with respect to each functional group can also be used.

As the silane coupling agent, a commercially available product or a synthetic product may be used. Examples of commercially available silane coupling agents include KBM-303, KBM-403, KBE-402, KBE-403, KBE-502, KBE-503, KBM-5103, KBM-573, KBM- , KBE-846, and KBE-9007 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

The silane coupling agents may be used singly or in combination of two or more kinds.

When the pressure-sensitive adhesive composition of the present invention contains a silane coupling agent, the content thereof is preferably 0.0001 part by mass or more and 10 parts by mass or less, more preferably 0.001 parts by mass or more and 5 parts by mass or less, based on 100 parts by mass of the main component (A) By mass, and particularly preferably from 0.01 to 3 parts by mass. With such a range, the durability can be improved.

[solvent]

The pressure-sensitive adhesive composition of the present invention may contain a solvent. Examples of the solvent include, but are not limited to, esters such as ethyl acetate and n-butyl acetate; Aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; And organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. These solvents may be used alone or in combination of two or more.

When the copolymer (a-3) is synthesized by the bulk polymerization method using a photopolymerization initiator as described above, the copolymer (a-3) called polymer syrup, in which at least one of the components (a-2) is contained as a solvent. Examples of the solvent used in the polymer syrup include the components (a-1) and (a-2) exemplified above. Therefore, the pressure-sensitive adhesive composition of the present invention may contain at least one of the component (a-1) and the component (a-2) as a solvent in the composition.

[Other components added]

The pressure-sensitive adhesive composition may contain, if necessary, known additives such as a crosslinking accelerator, an antioxidant, a filler, a colorant (such as a pigment or a dye), an ultraviolet absorber, an antioxidant, a chain transfer agent, a plasticizer, a softener, a surfactant, Other added components) may be contained within a range that does not impair the effects of the present invention.

[Production method of pressure-sensitive adhesive composition]

The method for producing the pressure-sensitive adhesive composition is not particularly limited. For example, in the case of the above-mentioned form (1) in which the curable compound in the main component (A) consists solely of monomers, the component (a-1), the component (a-2), the component (B), the photopolymerization initiator A crosslinking agent (C), a silane coupling agent, a solvent, and other added components, which are added in accordance with the above-mentioned method.

(2) wherein the curable compound in the main component (A) is a monomer and a polymer, the polymer syrup containing the component (a-1), the component (a-2) and the copolymer (a- (B) component, a photopolymerization initiator (D) and, if necessary, a crosslinking agent (C), a silane coupling agent, a solvent and other additives.

(3) or a solution thereof, the component (B), the photopolymerization initiator (D) and the crosslinking agent (C), if necessary, in the case of the form (3) wherein the curable compound in the main component ), A silane coupling agent, a solvent, and other additives.

As a method for adding the component (B) according to the present invention, the component (B) solution prepared by dissolving the component (B) in at least one of the component (a-1) It is preferable to adjust the total amount of the curable compound to be adjusted so as to have a desired content. According to this method, the component (B) is uniformly mixed in the pressure-sensitive adhesive composition, and at least one of the component (a-1) and the component (a-2) Is used as the solvent for the component (B), the effect on the physical properties of the pressure-sensitive adhesive composition and the pressure-sensitive adhesive film obtained after curing is small and suitable. In this case, the order of adding the crosslinking agent (C) and other additives to be added as needed is not particularly limited.

The content of the component (B) in the component (B) solution is not particularly limited, but is preferably 10% by mass or more and 75% by mass or less.

[Adhesive film]

In one aspect of the present invention, there is provided a pressure-sensitive adhesive film obtained by curing the pressure-sensitive adhesive composition of the present invention. The pressure-sensitive adhesive film of the present invention is a cured layer of the pressure-sensitive adhesive composition of the present invention, which is obtained by applying (for example, applying) a pressure-sensitive adhesive composition (solution) of the present invention to a suitable substrate . When two or more kinds of curing treatments (drying, crosslinking, polymerization, etc.) are carried out, they can be carried out simultaneously or in multiple steps. In the pressure-sensitive adhesive composition in which the main component (A) contains a monomer of the component (a-1) or the component (a-2), a final copolymerization reaction is typically performed as the curing treatment ) Component, (a-2) component and / or copolymer (a-3) is subjected to a copolymerization reaction to form a complete polymer. For example, when an active energy ray-curable pressure-sensitive adhesive composition is used, active energy ray irradiation is performed. If necessary, curing treatment such as crosslinking and drying may be carried out. When it is necessary to dry the composition with an active energy ray-curable pressure-sensitive adhesive composition, the active energy ray curing may be performed after drying. In the pressure-sensitive adhesive composition in which the main component (A) is composed only of the copolymer (a-3), typically, as the curing treatment, a treatment such as drying (heating and drying) and crosslinking is carried out as necessary.

In the application of the pressure-sensitive adhesive composition, one or more kinds of solvents may be appropriately added.

As the base material of the adhesive film, a separator described later can be used.

The coating method is not particularly limited, and various known methods can be used. For example, by roll coater, baker type applicator, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, An extrusion coating method and the like.

When the pressure-sensitive adhesive composition of the present invention contains a solvent, it is preferable to dry the solvent. As a method of drying the solvent, an appropriate method may be adopted depending on the purpose. Preferably, the coating film is heated and dried. The heat drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature to the above range, a pressure-sensitive adhesive film having excellent adhesive properties can be obtained.

The drying time can be appropriately set. Preferably 5 seconds or more and 30 minutes or less, more preferably 5 seconds or more and 20 minutes or less, and particularly preferably 10 seconds or more and 15 minutes or less. The heating and drying can be carried out two or more times by changing the conditions.

When the pressure-sensitive adhesive composition of the present invention comprises a photopolymerization initiator, the pressure-sensitive adhesive composition of the present invention may be applied directly onto an adherend, or after coating on a predetermined adherend such as a substrate or separator, And then an active energy ray is irradiated to obtain an adhesive film. Usually, the illuminance in the above wavelength 200nm 400nm or less and irradiated to 200mJ / cm ² or more 4000mJ / cm ² or less of 1mW / cm ² more than 200mW / cm ² or less ultraviolet light, the accumulated light quantity is the pressure-sensitive adhesive film obtained by photo-polymerization .

The thickness (dry film thickness) of the pressure-sensitive adhesive film of the present invention is not particularly limited and may be appropriately set according to the intended use. For example, from the viewpoints of adhesiveness and bending resistance, the thickness is preferably 1 μm or more and 250 μm or less, more preferably 5 μm or more and 250 μm or less, and further preferably 10 μm or more and 120 μm or less.

Further, when the adhesive film according to the present invention is exposed, the adhesive film can be protected with a sheet (separator) or the like which has been peeled off until it is provided for practical use.

As the separator, for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate (PET) Polyethylene terephthalate (PBT) film, polyurethane film, and ethylene-vinyl acetate copolymer film. Other suitable materials include porous materials such as paper, cloth, and nonwoven fabric, net, foam sheet, metal foil, and suitable paper foil such as a laminate thereof. However, the plastic film is suitably used because of its excellent surface smoothness.

The thickness of the separator is usually 5 占 퐉 or more and 200 占 퐉 or less, preferably 5 占 퐉 or more and 100 占 퐉 or less.

If necessary, the separator can be subjected to antistatic treatment such as mold releasing treatment, antifouling treatment, coating type, kneading type, and vapor deposition type with silicone, fluorine, long chain alkyl or fatty acid amide releasing agent or silica powder . Particularly, the releasability from the pressure sensitive adhesive film can be further improved by appropriately subjecting the surface of the separator to peeling treatment such as silicone treatment, long chain alkyl treatment or fluorine treatment.

The suitable content of each constituent unit of the polymer contained in the pressure-sensitive adhesive film formed from the pressure-sensitive adhesive composition of the present invention is preferably such that the content of each component ((a-1 ) Component and the component (a-2)) is applied as it is.

A pressure-sensitive adhesive film was prepared by bonding a polyethylene terephthalate (PET) film having a thickness of 188 占 퐉 and a PET film having a thickness of 100 占 퐉 on both surfaces of a 50 占 퐉 thick adhesive film to obtain a PET film having a thickness of 188 占 퐉, Of a three-layer structure bonded to a PET film was bent in a bending test machine with a PET film having a thickness of 188 占 퐉 and bent with a radius of curvature of 3 mm. The bending was performed at a bending temperature of 60 占 폚 at a bending speed of 300 cycles / The minimum number of lifting and bubbling between the adhesive film and the PET film when bending can be 30,000 or more, for example, 30,000 or more and 100,000 or less. Can be used in the flexible display in the above range. Bubbling and bubble generation can be evaluated by a conventional method using a naked eye or an optical microscope.

When the bending temperature is -20 ° C as described above, the adhesive film may be peeled off when it is evaluated in the same manner as described above, and the minimum number of bubbles may be 30,000 or more, for example, 30,000 or more and 50,000 or less. Can be used in the flexible display in the above range.

The adhesive film may have a storage elastic modulus G '(80) at 80 캜 of 1 x 10 ⁴ Pa or more and 5 x 10 ⁴ Pa or less, preferably 1.3 x 10 ⁴ Pa or more and 2.5 x 10 ⁴ Pa or less. Within this range, flexural resistance at high temperatures is good and can be used in flexible displays. The adhesive film preferably has a storage elastic modulus G '(-20) at -20 캜 of 0.5 × 10 ⁵ Pa or more and 1 × 10 ⁶ Pa or less, preferably 1.3 × 10 ⁵ Pa or more and 3.5 × 10 ⁵ Pa or less, 1.6 × 10 ⁵ or more ㎩ may be a 3 × 10 ⁵ ㎩. In the above range, the bending resistance can be excellent at a low temperature.

The adhesive film preferably has a glass transition temperature of -50 캜 or lower. With this range, bending resistance at high temperature and low temperature is more excellent. The glass transition temperature is more preferably -70 占 폚 to -50 占 폚, and still more preferably -65 占 폚 to -55 占 폚.

The adhesive film preferably has a ratio of a storage elastic modulus G '(-20) at -20 ° C to a storage elastic modulus G' (80) at 80 ° C of 1: 0.2 to 1: 1, preferably 1: 0.4 to 1: . In this range, the flexibility of the flexible display can be good because the flexural resistance is good at both the low temperature and the high temperature.

The adhesive film may contain a trace amount of a (meth) acrylic monomer having a carboxyl group or not at all, so that the rate of change in resistance in the following formula 1 may be 1% or less, for example, 0% or more and 1% or less. Can be used for display without corroding the metal coating layer.

<Formula 1>

Resistance change rate = (P ² - P ¹ ) / P ¹ x 100

(In the formula (1), P ¹ is an initial resistance (unit: Ω) measured for a specimen having electrodes at both ends of the pressure-sensitive adhesive film, and P ² is the resistance of the specimen after being left at 60 ° C. and 95% Resistance in ohms).

The rate of change in resistance was measured by laminating a polyethylene terephthalate (PET) film coated with indium tin oxide (ITO) on a glass plate, placing a laminate of an adhesive film and a PET film on an intermediate portion of the ITO surface, Specimens were prepared by forming electrodes by using silver paste on both ends of the film. The initial resistance (P ¹ ) was measured by connecting wires to both electrodes of the prepared specimens. The specimens were left at 60 ° C and 95% relative humidity for 250 hours and the resistance (P ² ) was measured. The rate of change in resistance was calculated using the equation (1).

[Adhesive sheet]

In one aspect of the present invention, there is also provided a pressure-sensitive adhesive sheet comprising an adhesive film formed by curing the pressure-sensitive adhesive composition of the present invention. The pressure-sensitive adhesive sheet is a so-called substrate-applied pressure-sensitive adhesive sheet (one-sided or two-sided pressure-sensitive adhesive sheet) prepared by fixing the pressure-sensitive adhesive film on one surface or both surfaces of a sheet-like base material (support) without intention of separating the pressure- Alternatively, the adhesive film may be formed on a substrate having releasability such as a release film (release liner) (a release sheet, a resin sheet subjected to release treatment on the surface, etc.), and a substrate supporting the adhesive film is removed (Double-sided) pressure-sensitive adhesive sheet in the form of a sheet.

The concept of the pressure-sensitive adhesive sheet referred to herein may include what is referred to as an adhesive tape, an adhesive label, an adhesive film, or the like. The adhesive film is not limited to the continuous film, and may be, for example, an adhesive film formed in a regular or random pattern such as a point shape or a stripe shape.

Examples of the substrate (support) include plastic substrates such as polyethylene terephthalate (PET) and polyester film, porous materials such as paper and nonwoven fabric, metal foil and the like.

The constituent material of the plastic substrate is not particularly limited as long as it can be formed into a sheet shape or a film shape, and examples thereof include polyethylene, polypropylene, poly-1-butene, Polyolefins such as ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer and ethylene-vinyl alcohol copolymer; Polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate; Polyamides such as polyacrylate, polystyrene, nylon 6, nylon 6,6, partially aromatic polyamide; Polyvinyl chloride, polyvinylidene chloride, polycarbonate, and the like.

The thickness of the base material is not particularly limited, but is preferably 4 탆 or more and 100 탆 or less, and more preferably 4 탆 or more and 50 탆 or less.

If necessary, the plastic substrate may be subjected to releasing treatment with a releasing agent such as silicone, fluorine, long chain alkyl or fatty acid amide type, silica powder, and the like, antifouling treatment, acid treatment, alkali treatment, primer treatment, corona treatment, plasma treatment, A coating type, a kneading type, a vapor deposition type, or the like.

Examples of the release film (release liner) include the separator exemplified above.

[Usage]

The above-described pressure-sensitive adhesive composition, pressure-sensitive adhesive film, and pressure-sensitive adhesive sheet of the present invention are applied to various applications and used, for example, in optical films. Such an optical film is not particularly limited and may be those used for forming an image display apparatus such as a liquid crystal display apparatus. For example, at least one of a polarizing plate and a retardation plate, and at least one of a conductive layer and a protective layer, a cover film, a transparent conductive film, a window film, a viewing angle enlarging film for improving the viewing angle of a liquid crystal monitor An optical compensation film, a brightness enhancement film for enhancing the contrast of the display, and further, those having these laminated layers. In particular, the pressure-sensitive adhesive composition, the pressure-sensitive adhesive film, and the pressure-sensitive adhesive sheet of the present invention can ensure bending resistance at low temperatures and high temperatures even when used in a flexible image display device.

The pressure-sensitive adhesive composition, pressure-sensitive adhesive film, and pressure-sensitive adhesive sheet of the present invention are suitably used for an image display device. That is, one aspect of the present invention is an image display device comprising an adhesive film formed by curing a pressure-sensitive adhesive composition. Examples of the image display device include a liquid crystal display device, an organic EL display device, a plasma display (PDP), a curved display, or a flexible display.

As described above, the present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film, a pressure-sensitive adhesive sheet, and an image display device, and relates to a pressure-sensitive adhesive sheet having excellent adhesive strength, bending resistance which hardly peels off even when bending is performed under high- Can be provided. In addition, the pressure-sensitive adhesive composition of the present invention is suitably used for the production of various films or sheets used for a liquid crystal display element such as a flexible display, an electroluminescence element, and the like, will be.

[ Example ]

The effects of the present invention will be described with reference to the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following embodiments. The conditions for leaving the room at room temperature, which are not specifically defined below, are all 23 ° C and 55% RH.

[Example 1]

&Lt; Preparation of polymer syrup 1 >

43 parts by mass of 2-ethylhexyl acrylate (AEH, manufactured by Nippon Shokubai Co., Ltd.) and 2 parts by mass of 2-ethylhexyl-diglycol acrylate (manufactured by Nippon Shokubai Co., Ltd.) were added to a reaction vessel equipped with a stirrer, 40 parts by mass of EHDG-AT and Kyoeisha Chemical Co., Ltd.), 15 parts by mass of 4-hydroxybutyl acrylate (4HBA, manufactured by Nippon Kasei Co., Ltd.) 1 part by mass of ethyl acrylamide (HEAA (registered trademark) manufactured by KJ Chemical Co., Ltd.), 1 part by mass of methyl methacrylate macromonomer (AA-6, manufactured by Toagosei Co., Ltd., Mn = 6000) 0.005 parts by mass of 2-dimethoxy-1,2-diphenylethane-1-one (Irgacure (registered trademark) 651, BASF Japan Co., Ltd.) was blended and UV irradiation was performed at room temperature (25 캜). The irradiation was carried out by irradiating light of ⁴ mW / cm ² by black light (wavelength: 360 nm), and when the temperature rise from the start of the reaction reached 7 캜, air was introduced into the flask by an air pump to stop the reaction. Thus, a polymer syrup 1 (polymerization degree 7%) containing the copolymer (a-3-1) was prepared. The weight average molecular weight of the copolymer (a-3-1) was 1.56 million. The above-mentioned &quot; polymerization rate &quot; is a value of the reaction rate calculated assuming that the case where all the injected monomers are polymers becomes 100%.

&Lt; Measurement of weight average molecular weight (Mw) of copolymer (a-3)

The weight average molecular weight (Mw) of the copolymer (a-3) was measured by GPC (gel permeation chromatography) under the following measurement conditions.

· Analysis device: HLC-8120GPC, manufactured by Tosoh Corporation

· Column: Toso Co., Ltd., G7000HXL + GMHXL + GMHXL

· Column size: Each 7.8 mmφ × 30 cm Total 90 cm

Column temperature: 40 ° C

Flow rate: 0.8 ml / min

Injection amount: 100 μl

Eluent: Tetrahydrofuran

Detector: Differential refractometer (RI)

Standard sample: polystyrene.

<Production of pressure-sensitive adhesive sheet>

98 parts by weight of the polymer syrup 1 was mixed with a terpene phenol copolymer (YS Polystar G150, a softening point as measured by a method according to JIS K5902 (2006), product of Yasuhara Chemical Co., Ltd.) as a terpene phenolic tackifier (B) 4 parts by mass of a 2-ethylhexyl acrylate solution having a concentration of 50% by mass of ethyleneglycol dimethacrylate (D-150 ° C), 1-hydroxycyclohexyl phenyl ketone (IRGACURE (registered trademark) 184, BASF Japan Co., 0.3 parts by mass were mixed to obtain a pressure-sensitive adhesive composition 1.

This pressure-sensitive adhesive composition 1 was applied on a release film (PET film obtained by releasing the silicone release agent on one side, trade name: MRF50, manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd., thickness: 50 占 퐉) using a Baker type applicator , To obtain a coated film. Thereafter, another peeling film similar to that described above was laminated on the obtained coating film, and ultraviolet light having an illuminance of 2.5 mW / cm ² (wavelength: 360 nm) was irradiated using black light (FL20SBL manufactured by Sankyo Denki Co., Ltd.) ) Was irradiated for 10 minutes (accumulated light quantity: 1500 mJ / cm ² ) to cure the coating film. As a result, a pressure-sensitive adhesive sheet in which an adhesive film having a thickness of 50 占 퐉 was held between two release films was obtained.

<Method of Measuring Adhesive Force>

Two pieces of PET film (trade name: MRF50, manufactured by Mitsubishi Chemical Corporation) having a thickness of 50 占 퐉 were prepared and corona treatment was performed on the surface on which the PET film was not subjected to the peeling treatment. The pressure-sensitive adhesive film was bonded to the surface subjected to the corona treatment using a laminator, cut into a width of 25 mm and a length of 100 mm, and then autoclaved at 50 DEG C and 0.5 MPa for 15 minutes to be completely adhered. Thereafter, the sample was allowed to stand in an atmosphere of 23 ° C / 55% RH for 1 hour, and the adhesive force was measured. Corona treatment was carried out by passing the PET film through the corona irradiating part set at a speed of 6.0 m / min and a voltage of 9.5 kV twice using a 3DT corona treating system (manufactured by Poly DYNE).

The adhesive strength was measured by using a tensile tester (Tensilon Universal Material Tester STA-1150, Orientech Co., Ltd.) at a peeling angle of 180 ° and a peeling speed of 0.3 m / min in an atmosphere of 23 ° C / 55% RH according to JIS Z0237 (N / 25 mm) when the PET film was pulled off in accordance with the test method of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive sheet.

&Lt; Method of measuring storage elastic modulus &

The pressure-sensitive adhesive sheet was cut into a size of 1.0 mm x 1.0 mm, and the two release films were peeled off to take out the pressure-sensitive adhesive films. The pressure-sensitive adhesive film (pressure-sensitive adhesive composition after curing) was laminated to a thickness of 3 mm ± 0.5 mm and then attached to a dynamic viscoelasticity measuring apparatus (Exstar DMS7100, Hitachi High-Tech Science Co., Ltd.). (-20) at -20 deg. C and a storage modulus G (-20) at 80 deg. C were measured in a temperature range of -30 deg. C to 100 deg. (80) were measured.

<Bending test>

An adhesive film having a thickness of 50 microns was attached to a PET film (trade name: A4300, manufactured by Toyobo Co., Ltd.) having a thickness of 188 占 퐉 using a hand laminate. Thereafter, a 100 μm thick PET film (product name: A4100, manufactured by TOYOBO CO., LTD.) Was placed on the pressure-sensitive adhesive film and autoclaved for 15 minutes at 50 ° C. and 0.5 MPa. As a result, a test sample in which two PET films were adhered by a 50 占 퐉 thick adhesive film was obtained.

A PET film having a thickness of 188 占 퐉 was bent inward under a temperature condition of 60 占 폚 or -20 占 폚 using a bending tester (trade name: Bending tester, manufactured by Tester Sangyo Co., Ltd.) to obtain a test sample. (1 hour 300 cycles, repetition frequency: 30000 times) to visually confirm whether peeling, peeling, wrinkling, etc. of the adhesive film and the PET film occurred. In Table 1, &quot;? &Quot; indicates that there was no peeling, peeling, or wrinkling; &Amp; cir &amp; indicates that wrinkles occurred in the adhesive film although no peeling occurred; And X indicates peeling, respectively. △ or more.

&Lt; Measurement of glass transition temperature >

A pressure-sensitive adhesive sheet was obtained in the same manner as in &quot; Measurement of storage elastic modulus &quot; except that the thickness of the pressure-sensitive adhesive film was changed to 100 탆.

A small amount of the adhesive film was taken out from the obtained pressure-sensitive adhesive sheet and attached to a differential scanning calorimeter (DSC, product of Seiko Instruments Inc., EXSTAR6000, autosampler: ASD-2). The temperature was measured at a temperature raising rate of 10 占 폚 / min and at a temperature range of -130 占 폚 to 100 占 폚, and the temperature of the endothermic peak derived from the pressure-sensitive adhesive film in the first heating step was measured using a pressure- And the glass transition temperature (Tg).

[Example 2]

99 parts by mass of the polymer syrup 1 prepared in the same manner as in Example 1 was dissolved in 2 mass parts of a 2-ethylhexyl acrylate solution containing 50% by mass of a terpene phenol copolymer (YS Polystar G150, produced by Yasuhara Chemical Co., Ltd.) , And 0.3 parts by mass of Irgacure 184 (registered trademark) were blended to obtain a pressure-sensitive adhesive composition 2. The obtained pressure-sensitive adhesive composition 2 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Example 3]

99.7 parts by mass of the polymer syrup 1 prepared in the same manner as in Example 1 was mixed with 50% by mass of a terpene phenol copolymer (TH130, softening point measured by a method according to JIS K5902 (2006), manufactured by Yasuhara Chemical Co., Ltd.: 130 占 폚) Ethylhexyl acrylate solution and 0.3 parts by mass of Irgacure (registered trademark) 184 were mixed to obtain a pressure-sensitive adhesive composition 3. The obtained pressure-sensitive adhesive composition 3 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Example 4]

The monomer composition of the polymer syrup 1 was changed to 83 parts by mass of 2-ethylhexyl acrylate and 17 parts by mass of 4-hydroxybutyl acrylate (the polymerization ratio of the obtained polymer syrup 2 was 7%), , Polymer syrup 2 was prepared. The weight average molecular weight (Mw) of the copolymer (a-3-2) contained in the obtained polymer syrup 2 was 2,000,000.

99.1 parts by mass of polymer syrup 2 was added with 2 parts by mass of 2-ethylhexyl acrylate containing 10% by mass of dipentaerythritol hexaacrylate (A-DPH, Shin Nakamura Kagaku Kogyo Co., Ltd.) , 1 part by mass of a 2-ethylhexyl acrylate solution containing 0.4 part by mass of a solution, a terpene phenol copolymer (YS Polystar G150, product of Yasuhara Chemical Co., Ltd.) in a concentration of 50 mass%, 1 part by mass of Irgacure (registered trademark) 184 were mixed together to obtain a pressure-sensitive adhesive composition 4. The obtained pressure-sensitive adhesive composition 4 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Example 5]

To 99.5 parts by mass of the polymer syrup 1 prepared in the same manner as in Example 1, 0.01 part by mass of trimethylolpropane tolylene diisocyanate (Coronate (registered trademark) L, manufactured by Tosoh Corporation) as a crosslinking agent, 1.0 part by mass of a terpene phenol copolymer 1 part by mass of a 2-ethylhexyl acrylate solution containing 50% by mass of a polyvinyl alcohol (YS Polystar G150, product of Yasuhara Chemical Co., Ltd.) and 0.3 parts by mass of Irgacure (registered trademark) 184 were blended to obtain a pressure- . The obtained pressure-sensitive adhesive composition 5 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative Example 1]

100 parts by mass of polymer syrup 1 prepared in the same manner as in Example 1 was compounded with 0.3 parts by mass of Irgacure (registered trademark) 184 to obtain Comparative Composition 1. The obtained Comparative Composition 1 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative Example 2]

95 parts by mass of the polymer syrup 1 prepared in the same manner as in Example 1 was mixed with 10 parts by mass of a 2-ethylhexyl acrylate solution containing a 50% by mass of a terpene phenol copolymer (YS Polystar G150, Yasuhara Chemical Co., Ltd.) , And 0.3 parts by mass of Irgacure (registered trademark) 184 were compounded to obtain Comparative Composition 2. The obtained Comparative Composition 2 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative Example 3]

50 mass% of an aromatic hydrocarbon resin (FTR-6125, softening point measured by a method according to JIS K5902 (2006), manufactured by Mitsui Chemicals, Inc.) was added to 95 mass parts of the polymer syrup 1 prepared in the same manner as in Example 1, 10 parts by mass of a 2-ethylhexyl acrylate solution and 0.3 parts by mass of Irgacure (registered trademark) 184 were mixed to obtain Comparative Composition 3. The obtained Comparative Composition 3 was coated and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative Example 4]

97 parts by mass of the polymer syrup 1 prepared in the same manner as in Example 1 was mixed with a mixture of a rosin-based tackifier (pale-colored rosin derivative, Fine Crystal KR-140, Arakawa Kagaku Kogyo Co., Ltd., JIS K5902 6 parts by mass of a 2-ethylhexyl acrylate solution containing 50 mass% of a softening point measured by one method: not less than 130 ° C and not more than 150 ° C) and 0.3 parts by mass of Irgacure (registered trademark) 184 Composition 4 was obtained. The obtained comparative composition 4 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative Example 5]

99.9 parts by mass of isooctyl acrylate (manufactured by Osaka Yuki Kagaku Kogyo Co., Ltd.) and 0.1 part by mass of hydroxyethyl acrylate (available from Osaka Yuki Kagakukyo Co., Ltd.) were added to a reaction vessel equipped with a thermometer, a condenser, Ltd.) and 0.3 parts by mass of 2,2'-azobisisobutyronitrile (manufactured by Otsuka Chemical Co., Ltd.) were added together with ethyl acetate and reacted at 60 ° C for 4 hours under a nitrogen gas stream. Thereafter, ethyl acetate was added to the reaction solution to obtain an acrylic polymer solution having a solid concentration of 30% by weight (weight average molecular weight of the acrylic polymer: 1.6 million). 0.15 parts by mass of trimethylolpropane tolylene diisocyanate (Coronate (registered trademark) L, manufactured by Tosoh Corporation) and 0.01 part by mass of 3-glycidoxypropyl tri (meth) acrylate were added to 100 parts by mass of the solid content of the acrylic polymer solution, Methoxy silane (KBM-403, Shin-Etsu Chemical Co., Ltd.) was blended to obtain Comparative Composition 5. Then, the above Comparative Composition 5 was coated on a separator made of a polyester film surface-treated with a silicone-based releasing agent and heat-treated at 150 ° C for 5 minutes to obtain a pressure-sensitive adhesive sheet having an adhesive film having a thickness of 50 μm.

[Comparative Example 6]

99.7 parts by mass of the polymer syrup 1 prepared in the same manner as in Example 1 was dissolved in a terpene phenol copolymer (YS Polystar G125, softening point measured by a method according to JIS K5902 (2006), product of Yasuhara Chemical Co., Ltd.: 125 ° C) 0.6 parts by mass of a 2-ethylhexyl acrylate solution containing 50% by mass of water and 0.3 parts by mass of Irgacure (registered trademark) 184 were mixed to obtain Comparative Composition 6. The obtained Comparative Composition 6 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative Example 7]

6 parts by mass of Irgacure (registered trademark) 184 was blended with 100 parts by mass of polymer syrup 1 prepared in the same manner as in Example 1 to obtain Comparative Composition 7. The obtained Comparative Composition 7 was applied and cured in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

Adhesion
[N / 25mm] Storage elasticity at -20 ° C
[Pa] Storage elasticity at 80 캜
[Pa] Tg (占 폚) Bending test -20 ° C 60 ° C Example 1 12.05 1.98E + 05 1.31E + 04 -63.8 ○ ○ Example 2 9.58 1.82E + 05 1.50E + 04 -65.5 ○ ○ Example 3 9.90 1.72E + 05 1.55E + 04 -63.1 ○ ○ Example 4 11.58 2.59E + 05 2.42E + 04 -62.9 ○ ○ Example 5 12.07 2.01E + 05 1.41E + 04 -63.8 ○ ○ Comparative Example 1 9.40 1.30E + 05 1.60E + 04 -62.1 ○ X Comparative Example 2 9.19 2.67E + 05 1.19E + 04 -64.4 X X Comparative Example 3 8.17 1.52E + 05 1.33E + 04 -65.3 ○ X Comparative Example 4 7.11 1.68E + 05 6.83E + 03 -63.0 X X Comparative Example 5 9.15 1.28E + 05 1.54E + 04 -62.0 △ X Comparative Example 6 9.18 1.30E + 05 1.12E + 04 -63.2 △ X Comparative Example 7 7.83 2.70E + 05 1.35E + 04 -63.8 X X

In Comparative Examples using a tackifier having a softening point lower than 130 캜 or a tackifier other than a tackifier phenol with respect to the main component (A) comprising a curable compound, no improvement in adhesion was observed. On the other hand, it can be seen that by adding an appropriate amount of a taperphenol-based tackifier having a softening point of 130 DEG C or more to the main component, it is possible to improve the bending resistance at high temperature and low temperature, and to increase the adhesive force. This is considered to be because the present invention can achieve a desired storage elastic modulus at a high temperature and a low temperature while having a high adhesive force.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (20)

100 parts by mass of a main component (A) comprising a curable compound, and
(B) having a softening point of 130 ° C or higher is contained in an amount of more than 0 parts by mass and less than 5 parts by mass, and
And a photopolymerization initiator (D) in an amount of 0.01 part by mass or more and 5 parts by mass or less.
The positive resist composition according to claim 1, wherein the main component (A) is a copolymer of a structural unit derived from a (meth) acrylic acid ester monomer (a-1) and a structural unit derived from a monomer (a- (A-3). &Lt; / RTI &gt;
The pressure-sensitive adhesive composition according to claim 2, wherein the content of the copolymer (a-3) is 1% by mass or more and 20% by mass or less based on the total amount of the main component (A).
The pressure-sensitive adhesive composition according to claim 2, wherein the copolymer (a-3) has a weight average molecular weight of not less than 1,000,000 and not more than 3.5 million.
The pressure-sensitive adhesive composition according to claim 1, wherein the main component (A) comprises less than 0.1% by weight of a (meth) acrylic monomer having a carboxyl group.
The pressure-sensitive adhesive composition according to claim 1, wherein the glass transition temperature after curing is -50 占 폚 or lower.
The composition according to claim 1, wherein the main component (A) is at least 50 mass% and not more than 99.9 mass% of the constitutional unit derived from the (meth) acrylic acid ester monomer (a-1) -2) from 0.1% by mass or more to 50% by mass or less.
The positive photosensitive resin composition according to claim 1, wherein the main component (A) is at least 50 mass% or more and 99.9 mass% or less of the constitutional unit derived from the (meth) acrylic acid ester monomer (a- (Meth) acrylic monomer (a-2-2) derived from a hydroxyl group-containing structural unit in an amount of not less than 0.1% by mass nor more than 50% by mass, a macromonomer having a polymerizable functional group (Meth) acrylate monomer (a-2-4), 0 mass% or more and 25 mass% or less of the constitutional unit derived from the monomer (a-2-3) Sensitive adhesive composition.
The pressure-sensitive adhesive composition according to claim 1, further comprising a crosslinking agent (C) in an amount of more than 0 parts by mass and less than 1 part by mass.
(A) composed of a curable compound, and
Sensitive adhesive (B) having a softening point of 130 ° C or higher, wherein the pressure-
The pressure-sensitive adhesive film was obtained by bonding a PET (polyethylene terephthalate) film having a thickness of 188 占 퐉 and a PET film having a thickness of 100 占 퐉 on both surfaces of the pressure-sensitive adhesive film having a thickness of 50 占 퐉 to a bending tester, Wherein the bending is performed at a bending temperature of 60 DEG C at a bending speed of 300 cycles / hour to obtain a pressure-sensitive adhesive film having a minimum number of times of lifting and bubbling between the pressure-sensitive adhesive film and the PET film of 30,000 or more times. .
The pressure-sensitive adhesive film according to claim 10, wherein the thickness of the pressure-sensitive adhesive film is 5 占 퐉 or more and 250 占 퐉 or less.
The method of claim 10, wherein the adhesive film has a minimum number of peelings and bubbles between the adhesive film and the PET film when bent at a bending temperature of -20 캜 and a bending speed of 300 cycles / Or more.
The pressure-sensitive adhesive composition according to claim 10, wherein the pressure-sensitive adhesive film has a resistance change ratio of 1%
<Formula 1>
Resistance change rate = (P ² - P ¹ ) / P ¹ x 100
(In the formula (1), P ¹ is an initial resistance (unit: Ω) measured for a specimen having electrodes at both ends of the pressure-sensitive adhesive film, and P ² is the resistance of the specimen after being left at 60 ° C. and 95% Resistance in ohms).
The adhesive film according to claim 10, wherein the adhesive film has a ratio of a storage elastic modulus G '(-20) at -20 캜 to a storage elastic modulus G' (80) at 80 캜 of 1: 0.2 to 1: .
The pressure-sensitive adhesive film according to claim 10, wherein the pressure-sensitive adhesive film has a storage elastic modulus G '(80) at 80 캜 of 1 x 10 ⁴ Pa or more and 5 x 10 ⁴ Pa or less.
The pressure-sensitive adhesive tape according to claim 10, wherein the pressure-sensitive adhesive film has a storage elastic modulus G '(-20) at -20 캜 of 0.5 × 10 ⁵ Pa or more and 1 × 10 ⁶ Pa or less,
The pressure-sensitive adhesive film according to claim 10, wherein the pressure-sensitive adhesive film has a glass transition temperature of -70 캜 to -50 캜.
The pressure-sensitive adhesive composition according to claim 10, wherein the pressure-sensitive adhesive composition comprises 100 parts by mass of the main component (A) composed of the curable compound, 0 parts by mass or more and less than 5 parts by mass of the terpene- phenolic tackifier (B) D) 0.01 part by mass or more and 5 parts by mass or less.
The thermosetting resin composition according to claim 18, wherein the main component (A) comprising the curable compound is at least one selected from the group consisting of a structural unit derived from a (meth) acrylic acid ester monomer (a-1) and a monomer derived from a monomer (a-2) copolymerizable with the (meth) acrylic acid ester monomer And a copolymer (a-3) containing a constituent unit,
The monomer (a-2) can be obtained by copolymerizing (a-2-1) an amide group-containing (meth) acrylic monomer, (a- Functional macromonomer and (a-2-4) a polyfunctional (meth) acrylate monomer.
An image display device comprising an adhesive film formed by curing the pressure-sensitive adhesive composition according to any one of claims 1 to 9 or the pressure-sensitive adhesive film according to any one of claims 10 to 19.