KR20170062366A - Adhesive composition, adhesive film, optical member, adhesive sheet and image display apparatus - Google Patents

Abstract

[PROBLEMS] To provide a pressure-sensitive adhesive composition which is excellent in durability, folding resistance, humidifying reliability and metal corrosion inhibition / prevention property
[MEANS FOR SOLVING PROBLEMS] The glass transition temperature of the main component (A) comprising a predetermined acrylic compound-containing pentaerythritol compound (B) in an amount of more than 0 parts by mass and 0.05 parts by mass or less, Deg.] C or higher and -60 deg. C or lower.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive composition, an adhesive film, an optical member, a pressure-sensitive adhesive sheet, and an image display device.

The present invention relates to a pressure-sensitive adhesive composition suitable for use in a flexible device, and an optical member, a pressure-sensitive adhesive sheet, and an image display device comprising the pressure-sensitive adhesive film, the pressure-sensitive adhesive film, and the pressure-

Currently, a liquid crystal display panel (LCD) or a plasma display panel (PDP) is used as a display panel. On the surface of the display panel, a laminate in which a plurality of films are laminated is usually bonded. 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 display panel is usually bonded by an adhesive film formed of various kinds of pressure-sensitive adhesives.

In recent years, from the viewpoints of design characteristics and a variety of methods of use, development of a flexible display including a curved display is progressing, and flexibility is demanded in the display panel. Organic electroluminescence panels (OLED) are mainly used for flexible displays such as curved displays.

In addition to the optical characteristics and durability required in the conventional planar display panel, the optical film laminate used in this flexible display may not be peeled off or peeled even if the optical film is deformed for a long time or subjected to a bending test Is required.

As an adhesive film used for a conventional optical film laminate for a flat display panel, Patent Document 1 discloses a pressure-sensitive adhesive for bonding a touch panel member, which is one of optical films, to an adhesive film comprising an alkyl (meth) acrylate monomer and an alkoxyalkyl There is proposed a pressure-sensitive adhesive for attaching a touch panel member, which is a copolymer containing an acrylate monomer. Further, Patent Document 2 discloses a photopolymerizable pressure-sensitive adhesive composition comprising an acryl prepolymer containing N-vinyl-2-pyrrolidone and (meth) acrylic acid hydroxyalkyl, and a photopolymerization initiator composition comprising dipentaerythritol hexaacrylate and a photopolymerization initiator .

<Prior Art Literature>

<Patent Literature>

(Patent Document 1) JP2013-186808 A

(Patent Document 2) JP2011-099078 A

Flexible displays, such as organic electroluminescence panels (OLEDs), are expected to be used in a variety of environments, so that their durability in use in a wide range of temperatures, as well as folding resistance (flex resistance) under both high and low temperature conditions, . However, when the pressure-sensitive adhesive described in Patent Document 1 or Patent Document 2 is used in the pressure-sensitive adhesive film of a flexible display, it is not satisfactory in terms of durability and folding resistance (flex resistance) under two conditions of high temperature and low temperature . Considering that the use environment of the flexible display is diversified, the adhesive film which can be used for the flexible display has a humidifying reliability (a property of suppressing an increase in haze even in a high humidity environment) and a metal corrosion inhibiting & And so on.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a pressure-sensitive adhesive composition which is excellent in durability, folding resistance, humidifying reliability and metal corrosion inhibition and prevention properties, in view of the above circumstances.

The inventors of the present invention conducted intensive studies in order to solve the above problems and found that a pentaerythritol compound (B) was obtained by reacting 100 parts by mass of a main component (A) made of a curable compound containing a predetermined acrylic compound 0 parts by mass or more and 0.05 parts by mass or less, and the glass transition temperature after curing is from -70 占 폚 to -60 占 폚. The present invention has been accomplished based on this finding.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a pressure-sensitive adhesive composition excellent in durability, folding resistance, humidifying reliability and metal corrosion inhibition. The pressure-sensitive adhesive composition according to the present invention is particularly suitable for flexible display applications.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a test system for suppressing metal corrosion inhibition. FIG.

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]

One aspect of the present invention relates to a curable composition comprising 100 parts by mass of a main component (A) comprising a curable compound; And 0 to less than 0.05 parts by mass of a pentaerythritol compound (B); The main component (A) is a mixture of a (meth) acrylic acid ester monomer (a-1) and a hydroxyl group-containing (meth) acrylic monomer (a-2); And a structural unit (2) derived from the (meth) acrylic acid ester monomer (a-1) and the hydroxyl group-containing (meth) acrylic monomer (a-2) (a-3); And the glass transition temperature after curing is from -70 占 폚 to -60 占 폚. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a pressure-sensitive adhesive composition excellent in durability, folding resistance, humidifying reliability and metal corrosion inhibition.

For some reason, the details of how the above-mentioned effects are obtained by the pressure-sensitive adhesive composition of the present invention are unclear, but they are considered as follows. That is, if the glass transition temperature of the pressure-sensitive adhesive composition after curing is too high, the cured product becomes too soft at a high temperature (for example, 85 占 폚), and it becomes difficult to obtain the folding resistance at high temperature. If the glass transition temperature of the pressure-sensitive adhesive composition after curing is too low, it is considered that sufficient flexibility is not obtained at a low temperature (for example, -20 占 폚) and it is difficult to obtain a folding resistance at a low temperature. In contrast, the present inventors have found that (meth) acrylic acid ester monomer (a-1) (or copolymer (a-3) containing a constituent unit derived therefrom) having a low glass transition temperature of homopolymer (For example, -85 占 폚) and a low temperature (for example, -20 占 폚) by setting the glass transition temperature of the pressure-sensitive adhesive composition after curing to -70 占 폚 to -60 占 폚 by using, as a main component, The folding resistance of the film is improved.

Although the reason for this is unclear for a detailed reason, unlike the case of using a polyethylene glycol (glycol) compound or a trimethylolpropane compound having an ethylenic unsaturated group, the folding resistance is improved by using the pentaerythritol compound (B) They found. It is considered that the pressure-sensitive adhesive composition of the present invention contains the pentaerythritol compound (B), and thus the folding resistance, particularly the folding resistance at a high temperature (for example, 85 캜) is further improved due to the flexible molecular structure thereof. Also, by suppressing the content of the pentaerythritol compound (B) to a certain level, it is possible to prevent the adhesive strength of the pressure-sensitive adhesive composition, which is obtained by curing the pressure-sensitive adhesive composition, from excessively increasing to decrease the adhesive strength and durability.

In the pressure-sensitive adhesive composition of the present invention, the curable compound (a-3) containing a hydroxyl group-containing (meth) acrylic monomer (a-2) having a high polarity (or a copolymer As a main component. By adopting such a constitution, it is possible to secure adhesion force and durability while suppressing the content of the pentaerythritol compound (B) to a certain degree owing to the high polarity of the hydroxyl group-containing (meth) acrylic monomer (a-2) &Lt; / RTI &gt; Further, the hydroxyl group-containing (meth) acrylic monomer (a-2) (or the copolymer (a-3) containing the constituent unit derived therefrom) Corrosion is considered to be difficult to occur.

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 gel fraction of 70% or more and 90% or less, more preferably 70% or more and 84% or less and more preferably 75% or more and 84% or less as measured by the method described in the examples. With such a range, punching or slit processing can be performed quickly as an optical member having an adhesive film. In order to set the gel fraction as described above, the conditions may be appropriately selected, for example, the addition amount of each component is adjusted to the above range.

The pressure-sensitive adhesive composition of the present invention, in view of the bending resistance at a high temperature, the storage elastic modulus at 85 ℃ after curing G '(85) is preferably 1 × 10 ⁴ ㎩ than ⁴ × 10 4 ㎩ less and, 2.0 × 10 ^{More preferably from 4} Pa to 3.5 x 10 ⁴ Pa and from 2.2 x 10 ⁴ Pa to 3.5 x 10 ⁴ Pa. Within this range, bending resistance at high temperatures may be good.

The pressure-sensitive adhesive composition of the present invention preferably has a storage elastic modulus G '(-20) at -20 캜 after curing of less than or equal to 1 x 10 ⁴ Pa and less than 5 x 10 ⁴ Pa in view of bending resistance at low temperatures, is more than ⁴ × 10 to 3.5 × 10 ⁴ ㎩ ㎩ or less, 1.5 × 10 ⁴ or more to 3.2 × 10 ⁴ ㎩ ㎩ or less is more preferable. Within this range, bending resistance at high temperatures may be good.

On the other hand, the storage elastic moduli G '(85) and G' (- 20) employ the values measured by the methods described in the examples. The storage elastic moduli G '(85) and G' (- 20) can be controlled by the composition of the main component (A) or the like.

The glass transition temperature of the pressure-sensitive adhesive composition of the present invention after curing may be from -70 deg. C to -60 deg. C, but from -66 deg. C to -60 deg. C and from -65 deg. C to -60 deg C desirable. The glass transition temperature of the pressure-sensitive adhesive composition after curing can be determined by the method described in Examples. In order to keep the glass transition temperature after curing of the pressure-sensitive adhesive composition within the above-mentioned range, a monomer to be used for preparing the main component (A) may be suitably selected in consideration of the glass transition temperature of the homopolymer. (Meth) acrylic acid ester monomer (a-1) having a low glass transition temperature of the homopolymer and a monomer having relatively high glass transition temperature (for example, a hydroxyl group-containing (meth) acrylic monomer (a- 2), the monomer (a ') copolymerizable with the component (a-1) and the component (a-2) may be suitably adjusted.

Hereinafter, each component of the pressure-sensitive adhesive composition of the present invention will be described in 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 &quot; (meth) acrylic &quot; 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.

In the present specification, the "pressure-sensitive adhesive composition" is also simply referred to as "pressure-sensitive adhesive". In the present specification, the term "(co) polymer" is a generic term of "polymer (homopolymer)" and "copolymer".

[Main component (A)]

The main component (A) used in the present invention is composed of a curable compound (except for the pentaerythritol compound (B)). In the present invention, the (meth) acrylic acid ester monomer (hereinafter also referred to simply as "component (a-1)") and the hydroxyl group-containing (meth) acrylic monomer (a-2) (hereinafter, also simply referred to as &quot; component (a-2) &quot;); (1) derived from the (meth) acrylic acid ester monomer (a-1) and the structural unit (2) derived from the hydroxyl group-containing (meth) acrylic monomer And a copolymer (a-3). The main component (A) contains the copolymer (a-3) comprising the constituent unit (1) derived from the component (a-1) and / or the component (a- The glass transition temperature of the pressure-sensitive adhesive composition after curing can be lowered to -70 占 폚 or higher and -60 占 폚 or lower. Further, the main component (A) contains the copolymer (a-3) containing the constituent unit (2) derived from the component (a-2) Excellent adhesion to an optical film such as a polarizing plate having a high polarity can be ensured while the content of the compound (B) is controlled to a certain degree. As the curable compound contained in the main component (A), an active energy ray-curable monomer such as a (meth) acrylic compound and its (co) polymer, a (meth) acryloyl group, a vinyl group, an allyl group, A polyester resin, a polyether resin, a polyurethane resin or an epoxy resin containing a polymerizable functional group such as a dithiocarbamate group, a diazo group, a cinnamylidene group and / or a cinnamoyl group, and combinations thereof .

The viscosity of the main component (A) is preferably from 500 mPa 占 퐏 to less than 5000 mPa 占 퐏 at 20 占 폚 to 25 占 폚, and more preferably from 1,000 mPa 占 퐏 to 4500 mPa 占 퐏, from the viewpoint of coatability and adhesiveness of the pressure- Is more preferable. The viscosity is a value measured by the method described in the embodiment.

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

(1) a form comprising the components (a-1) and (a-2)

(2) a component (a-1); (a-2) component; And a copolymer (a-3) (hereinafter referred to simply as the copolymer (a-3)) containing the constituent unit (1) derived from the component (a- (The form in which the curable compound is composed of a monomer and a polymer, in the form of a so-called 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) _p -Q is introduced into the ester moiety of the (meth) acrylic acid ester. In the above "- (AO) _p -Q", A is an alkylene group, Q is an alkyl group, and p is an integer of 1 or more and 20 or less.

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

The number of carbon atoms of the alkyl group or the group represented by - (AO) _p -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 in the form of a straight chain, a branched chain or a ring, but it is preferably a straight chain or branched chain from the viewpoint of lowering the glass transition temperature. In the case of a ring, the number of carbon atoms is 3 or more.

In the group represented by - (AO) _p -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). At this time, p is preferably an integer of 1 or more and 6 or less, more preferably an integer of 1 or more and 4 or less, 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, and still more preferably 2 or more and 10 or less in view of efficiently exhibiting the desired effect of the present invention. Is 2 or more and 8 or less. Specific examples of such an alkyl group include those listed above.

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) _p -Q.

The alkyl group in R ₂ of the formula (1) is not particularly limited, and examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, ethyl group, n-propyl group, isopropyl group, n- Butyl group, an isobutyl group, an isobutyl group, an n-hexyl group, a 2-hexyl group, a 3-hexyl group, a cyclohexyl group, a 1-methylcyclohexyl group, an n-heptyl group, An alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isopropyl group, A decyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and 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.

The group represented by - (AO) _p -Q in R ₂ of formula (1) may be an alkoxyalkyl group. Examples of the alkoxyalkyl group include a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, a propoxyethyl group, a butoxyethyl group, a methoxypropyl group, a methoxybutyl group, a 2-ethylhexyloxyalkyl group (having 1 to 4 carbon atoms in the alkyl group) .

Specific examples of the (meth) acrylic acid ester monomer (a-1) in which R ₂ in the formula (1) is a group represented by - (AO) _p -Q include methoxyethyl (meth) acrylate, ethoxymethyl (Meth) acrylate, ethoxyethyl (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 Acrylate, methoxy triethylene glycol (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxy dipropylene glycol Preferable.

Among the specific examples of the (meth) acrylic ester monomer (a-1), from the viewpoint of lowering the glass transition temperature and polarity after curing, and securing excellent flexibility and adhesion, The (meth) acrylic acid ester monomer (a-1) is preferably a homopolymer having a glass transition temperature of less than -60 占 폚, preferably from -80 占 폚 to -61 占 폚, It is particularly preferable that the epoxy resin is at least one selected from the group consisting of hexyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate and ethoxy-diethylene glycol (meth) acrylate.

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 and Light Ester L (manufactured by Kyoeisha Chemical Co., (Available from Osaka Organic Chemical Industry Co., Ltd.), AM-90G, AM-130G (manufactured by Shin-Nakamura Kagaku Kyogo Co., Ltd., Shin-Nakamura Chemical Co., Ltd.), Biscott # 190, 2-MTA, MPE400A, MPE550A Ltd.) are suitable.

<(a-2) Hydroxyl group-containing (meth) acrylic monomer>

(A-2) containing a hydroxyl group-containing (meth) acrylic monomer (a-2) and / or a hydroxyl group-containing (meth) acrylic monomer (a- 3) is contained in the main component (A), excellent adhesion to an optical film such as a polarizing plate having a high polarity can be ensured while the content of the pentaerythritol compound (B) is controlled to a certain degree.

The hydroxyl group-containing (meth) acrylic monomer may include at least one of a non-amide monomer having no amide group, and an amide monomer having an amide group.

As the (meth) acrylic monomer having a hydroxyl group, the non-amide monomer is typically represented by the following formula (2-1):

Here, in the formula (2-1)

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 phenoxy group, a phenoxyalkyl group (the number of carbon atoms in the alkyl group is 1 to 8), a phenyl group or a cyclohexyl group as a substituent. The alkyl group having 1 to 8 carbon atoms may be appropriately selected from the above.

As the hydroxyl group-containing (meth) acrylic monomer, the amide monomer may have a structure represented by the following formula (2-2):

Here, in the formula (2-2)

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 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 may have at least one alkyl group having 1 to 8 carbon atoms, a phenyl group or a cyclohexyl group as a substituent. The alkylene group having 1 to 10 carbon atoms is a divalent substituent obtained by removing one hydrogen atom of an alkyl group having 1 to 10 carbon atoms.

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.

As the component (a-2), it is preferable to use at least one member selected from the group consisting of 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- (Meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl ) Acrylamide, N- (1-methyl-2-hydroxyethyl) (meth) acrylamide and N-isopropyl-hydroxy (meth) acrylamide. Among them, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and the like are preferable from the viewpoint that the homopolymer has a relatively low glass transition temperature desirable.

HEA, HPA, 4-HBA (manufactured by Nippon Shokubai Co., Ltd.), 4HBA, CHDMMA (manufactured by Nippon Kasei K.K.), BEA, HPA, (Trade name, manufactured by Kyowa Kagakakaku K.K.), HEAA (trade name) manufactured by Kyoeisha Chemical Co., Ltd.), light ester HOA (N), light ester HOP- (Registered trademark) (manufactured by KJ Chemical Co., Ltd.) and N-MAN (manufactured by MIKI RIKEN KOGYO CO., LTD.).

These (a-2) components may be used alone or in combination of two or more. The component (a-2) may be a commercially available product or a synthetic product.

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

The main component (A) may contain a monomer (a ') component copolymerizable with the component (a-1) and the component (a-2) as long as the object effect of the present invention is achieved. (a'-1) having an amide group (hereinafter also referred to as "component (a'-1)"), a macromonomer having a polymerizable functional group (a'-2) (Hereinafter also referred to as "component (a'-2)") and other polymerizable monomer (a'-3) (hereinafter also referred to as "component (a'-3)").

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

The (a'-1) component is not particularly limited as long as it has an amide group in the (meth) acrylic monomer. The component (a'-1) does not contain a hydroxyl group. (a'-1) component is typically represented by the following formula (3):

Here, in the formula (3)

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 or an alkyl group having 1 to 10 carbon atoms,

R ₁₁ 'is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group, an epoxy group, an alkoxy group having 1 to 6 carbon atoms, or a dimethylamino group.

The divalent organic group is not particularly limited, but an alkylene 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.

The alkyl group having 1 to 10 carbon atoms is as described above for Formula (2-2).

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. The acyl group includes acetoacetoxy group or 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.

In addition, R ₁₀ 'and R ₁₁ ' may form a ring having 2 to 8 carbon atoms, or may have an oxygen atom (that is, an oxygen-containing heterocyclic group) or a sulfur atom (that is, a sulfur-containing heterocyclic group) do.

(Meth) acryloyl morpholine, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, diacetone , N-dimethylaminopropyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butoxymethylacrylamide, N-isobutoxymethyl acrylamide, N-methoxymethylacrylamide, (Meth) acryloylpolyamine, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, Diacetone (meth) acrylamide, and (meth) acrylamide. Further, the (meth) acrylic monomer having an (a'-1) amide group may be N, N-methylene bis (meth) acrylamide.

(registered trademark), DEAA (registered trademark) (manufactured by KJ Chemical Co., Ltd.), DAAm (registered trademark), and the like are commercially available products of the component (a'- NBMA, IBMA, NMMA, TBAA, and MBAA (manufactured by MRC Unitech Co., Ltd.) are suitable.

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

The main component (A) according to the present invention may contain a macromonomer (a'-2) having a polymerizable functional group. The component (a'-2) 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 believed 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. On the other hand, 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.

The polymerizable functional group of the component (a'-2) is preferably a group having an ethylenically unsaturated double bond (ethylenic unsaturated group). 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 it is more preferable that the polymerizable group exists only at one end of the macromonomer from the standpoint 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.

The polymer chain portion of the component (a'-2) may be at least one member selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, stearyl (meth) (Meth) acrylate having a repeating unit derived from t-butyl (meth) acrylate, styrene, acrylonitrile, hydroxy (meth) acrylate, ethylhexyl (Co) polymer. 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) 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 also 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) Acrylate, t-butyl (meth) acrylate, styrene, acrylonitrile, or a polysiloxane in which an organic group is bonded to a silicon atom (a polyorganosiloxane ). Among them, X ₂ is preferably a polymer obtained by homopolymerizing methyl (meth) acrylate, styrene, n-butyl (meth) acrylate or isobutyl (meth) acrylate, copolymerizing acrylonitrile and styrene Or a polyorganosiloxane. From the viewpoint of durability at a high temperature, X ₂ is preferably a polymer obtained by copolymerizing methyl (meth) acrylate, styrene, isobutyl (meth) acrylate or acrylonitrile and styrene Particularly preferred. Or, from the viewpoint of bending resistance at low temperatures, X ₂ is preferably a polyorganosiloxane, and particularly preferably a polydimethylsiloxane. On the other hand, 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 with 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) is preferably in the range of 2000 to 20000, more preferably in the range of 2000 to 10000, and more preferably in the range of 4000 to 8000 More preferable. When 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) 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 shall be a value in terms of polystyrene measured by GPC (Gel Permeation Chromatography).

The component (a'-2) may be a commercially available product or a synthetic product. (a'-2) 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, A method in which a phosphoric acid chloride or the like is allowed to act; (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 and then forming a macromonomer with glycidyl methacrylate Method can be used.

By preparing a 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).

(trade name: 45% AA-6 (AA-6S)) having a methacryl group at the terminal and a polymer chain portion of polymethylmethacrylate (PMMA) as a commercially available product of the component (a'- (Trade name: AS-6S, AS-6, manufactured by TOAGOSEI CO., LTD.) In which the polymer chain portion is polystyrene, a styrene / acryl (Trade name: AN-6S; manufactured by TOAGOSEI CO., LTD.), A macromonomer in which the polymer chain portion is polybutyl acrylate (product name: AB-6; manufactured by TOAGOSEI CO., LTD.), (Trade name: AW-6S; manufactured by TOAGOSEI CO., LTD.), Which is isobutyl methacrylate, and a macromonomer (trade name: AK-5, manufactured by TOAGOSEI CO., LTD.) In which the polymer chain portion is polydimethylsiloxane. These macromonomers may be used alone or in combination of two or more.

«(A'-3) Other Polymerizable Monomers»

Specific examples of the other polymerizable monomer copolymerizable with the component (a-1) and the component (a-2) include epoxy groups such as glycidyl (meth) acrylate and methyl glycidyl (meth) ; Amino groups such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate and 2 - ((meth) acryloxy) ethyltrimethylammonium chloride A (meth) acrylic monomer having a hydroxyl group; (Meth) acryl monomers having a urethane group such as urethane (meth) acrylate; (meth) acrylic vinyl monomers having a phenyl group such as p-tert-butylphenyl (meth) acrylate and o-biphenyl (meth) acrylate; Vinyl monomers having silane groups such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (? -Methoxyethyl) silane, vinyltriacetylsilane and methacryloyloxypropyltrimethoxysilane; Styrene, chlorostyrene, alpha -methylstyrene, vinyltoluene, vinyl chloride, vinyl acetate, vinyl propionate, acrylonitrile, and vinyl pyridine. These other monomers may be used alone or in combination of two or more.

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

The content of the component (a-1) is preferably 70% by mass or more with respect to the total amount of the main component (A) from the viewpoint of lowering the glass transition temperature after curing. (a-1) component is formula (1) R ₂ is an alkyl group of (meth) acrylic acid ester monomer (a-1) and formula (1) R ₂ is a - group represented by (AO) _p -Q (meth ) Acrylic acid ester monomer (a-1) is preferable in terms of flexibility. The upper limit of the content of the component (a-1) is preferably 99.9% by mass or less, because it is excellent in various durability, excellent in bending resistance at high temperature, and improved in adhesion at high temperature. The content of the component (a-1) is preferably from 75% by mass to 99% by mass, from 75% by mass to 97% by mass, from 75% by mass to 75% by mass, from the viewpoint of ensuring an excellent adhesive force while lowering the glass transition temperature of the pressure- More preferably not less than 95% by mass, and further preferably not less than 75% by mass and not more than 90% by mass. Within the above range, durability, bending resistance at high temperature, and adhesion at high temperature can be good. Particularly, the (meth) acrylic acid ester monomer (a-1) in which R ₂ in the formula (1) is an alkyl group is 20 mass% or more and 99.9 mass% or less, preferably 20 mass% or more and 85 mass% By mass or less. The (meth) acrylic acid ester monomer (a-1) in which R ₂ in the formula (1) is a group represented by - (AO) _p -Q is not less than 10% by mass and not more than 99.9% by mass relative to the total amount of the main component (A) By mass to 15% by mass or more and 60% by mass or less. Within the above range, durability, bending resistance at high temperature, and adhesion at high temperature can be good.

The content of the component (a-2) is preferably not less than 0.1% by mass and not more than 30% by mass, more preferably not less than 0.5% by mass and not more than 25% by mass with respect to the total amount of the main component (A) , 1 mass% or more and 25 mass% or less, 5 mass% or more and 25 mass% or less, and 15 mass% or more and 25 mass% or less. Within this range, adhesion and durability may be good. The content of the component (a-2) represented by the above-mentioned (2-1) is preferably not less than 0.1 mass% and not more than 30 mass%, more preferably not less than 0.5 mass% nor more than 25 mass% 25 mass% or less, 5 mass% or more and 25 mass% or less, and 15 mass% or more and 25 mass% or less. The content of the component (a-2) represented by the above-mentioned (2-1) is 0 mass% or more and 30 mass% or less, preferably 0 mass% or more and 10 mass% or less relative to the total amount of the main component (A) % Or more and 5 mass% or less, and 0.1 mass% or more and 5 mass% or less. Within this range, adhesion and durability may be good.

The content of the component (a ') is preferably 0 mass% or more and 10 mass% or less with respect to the total amount of the main component (A). The content of the component (a ') is more preferably 0% by mass or more and 7% by mass or less, 0% by mass or more and 5% by mass or more from the viewpoint of ensuring sufficient amount of the component (a- Or less, and 0.5 mass% or more and 7 mass% or less. In the above range, the adhesive strength and the bending resistance can be further improved under the condition that the glass transition temperature after curing is not improved. Particularly, the component (a'-1) is 0 mass% or more and 10 mass% or less, 0 mass% or more and 7 mass% or less, 0 mass% or more and 5 mass% or less, or 0.5 mass% or more 7% by mass or less is preferable. (a'-2) is 0 mass% or more and 10 mass% or less, 0 mass% or more and 7 mass% or less, 0 mass% or more and 5 mass% or less, or 0.5 mass% or more and 7 mass % Or less. In the above range, the adhesive strength and the bending resistance can be further improved under the condition that the glass transition temperature after curing is not improved.

&Quot; Form (2) &quot;

(1) and (a-2) derived from the component (a-1), the component (a-2) and the component (A form in which the curable compound is composed of a monomer and a polymer) including the copolymer (a-3) (hereinafter also referred to simply as the copolymer (a-3)) containing the unit (2). (A-1), (a-2) and optionally (a '), which are unreacted raw monomers, of the raw monomers of the copolymer (a-3) called polymer syrup, which is a solvent for dissolving the polymer (a-3).

A suitable content of the component (a-1), the component (a-2) and the component (a ') in the form of the component (2) And the description thereof 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, (a-2) component and (a ') component).

That is, the copolymer (a-3) contained in the form of (2) is a copolymer comprising 70 to 99.9% by mass of a constituent unit derived from the (meth) acrylic acid ester monomer (a- ) Constituent units derived from the acrylic monomer (a-2) in an amount of not less than 0.1 mass% and not more than 30 mass%, and a monomer copolymerizable with the components (a-1) (The total amount of the constituent units derived from (a-1), (a-2) and (a ') is 100% by mass or less) More preferably, the copolymer (a-3) contained in the form of the (meth) acrylic ester monomer (a-1) contains 75 to 95 mass% ) Constituent units derived from the acrylic monomer (a-2) in an amount of not less than 5% by mass and not more than 25% by mass, and a monomer copolymerizable with the components (a-1) % Or more and 5 mass% (Provided that the total amount of the components (a-1), (a-2) and (a ') 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 such that the coating property of the pressure- From the viewpoint of being excellent, it is 5 mass% or more and 25 mass% or less, and more preferably 7 mass% or more and 20 mass% or less. The content of the copolymer (a-3) can be controlled by, for example, controlling the polymerization rate in a bulk polymerization method using a photopolymerization initiator described later.

&Quot; Form (3) &quot;

As an embodiment according to the present invention, there can be mentioned a form in which the main component (A) is composed of the copolymer (a-3) (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), the component (a-2), and the component (a ')).

[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.

In one embodiment of the pressure-sensitive adhesive composition of the present invention, the copolymer (a-3) contains the (meth) acrylic acid ester monomer (a-1) and the hydroxyl group-containing (meth) acrylic monomer (a-2) And then polymerized by solution polymerization of the reaction solution. As a solution polymerization method using a thermal polymerization initiator, for example, by using ethyl acetate, toluene, methyl ethyl ketone or the like as a solvent, a thermal polymerization initiator (a-3) is added to 100 parts by mass of the total amount of the starting monomers of the copolymer Preferably at least 0.01 part by mass and at most 1 part by mass, and the reaction is carried out at a reaction temperature of 40 占 폚 or more and 90 占 폚 or less (or 60 占 폚 or more and 90 占 폚 or less) under a nitrogen atmosphere for 3 hours to 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-methylpropionamide], 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis [2- Azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate, 2,2'-azobis 2-methylpropionamidine) hydrate, 2,2'-azobis [N- (2-carboxyethyl) Bis (2-imidazolin-2-yl) propane], 2,2'-azobis (1-imino-1-pyrrolidino- Azo compounds such as azobis [2-methyl-N- (2-hydroxyethyl) propionamide]; 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)). (A-1), the component (a-2) and the copolymer (a-3) can be obtained by adding the obtained copolymer (a- (Polymer syrup) (the above-mentioned form (2)).

The bulk polymerization method using a photopolymerization initiator is not particularly limited. For example, the raw material monomer of the copolymer (a-3) and a photopolymerization initiator are added, and the reaction initiation temperature is adjusted to 20 占 폚 or more and 35 占 폚 or less 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), the component (a-2) and the optional component (a '), which are unreacted raw monomers, are used as a solvent for dissolving the copolymer (a-3) (polymer syrup) containing the component (a-1), the component (a-2) and 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. That is, in one preferred embodiment of the pressure-sensitive adhesive composition of the present invention, the copolymer (a-3) is obtained by copolymerizing the (meth) acrylic acid ester monomer (a-1) and the hydroxyl group- ) In the reaction solution. 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 illuminance is preferably 3.2 mW / cm ² or more and 5.6 mW / cm ² or less.

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 (Manufactured by BASF Japan Co., Ltd.), Esacure (registered trademark) KIP150, TZT (manufactured by DKSH Japan Co., Ltd.), Kayacure (registered trademark) ) 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 2.5 million, and more preferably from 1.2 to 1.9 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. On the other hand, if it is less than 2.5 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 -70 ° C or higher and -60 ° C or lower.

[Pentaerythritol compound (B)]

The pressure-sensitive adhesive composition according to the present invention comprises a pentaerythritol compound (B) in a proportion of 0 parts by mass or more and 0.05 parts by mass or less based on 100 parts by mass of the main component (A). As a result, it is possible to improve the folding resistance while preventing the adhesive strength and the durability from being lowered.

The "pentaerythritol compound (B)" (hereinafter, simply referred to as "component (B)") in the present invention is a compound having a pentaerythritol skeleton and having a group having an ethylenically unsaturated double bond in the molecule An unsaturated group). Specific examples of the ethylenic unsaturated group include a vinyl group, an allyl group, a (meth) acryloyl group and a propenyl group.

The component (B) is typically represented by the following formula (5): &lt; EMI ID =

In the formula (5), R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each independently represent a hydrogen atom or an ethylenic unsaturated group; At least one of R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ is an ethylenic unsaturated group; Y ₁ , Y ₂ , Y ₃ and Y ₄ each independently represent a single bond or an alkylene oxide group having 1 to 6 carbon atoms and having 1 to 20 repeating units; and n represents an integer of 1 or more and 6 or less.

In the formula (5), the ethylenic unsaturated group is preferably a (meth) acryloyl group.

From the viewpoint of durability and folding resistance, it is preferable that in the formula (5), two or more and three or less of R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ are ethylenic unsaturated groups.

More specifically, the alkylene oxide group having 1 to 6 carbon atoms is, for example, a methylene oxide group, an ethylene oxide group, a propylene oxide group, a butylene oxide group, a pentylene oxide group or a hexylene oxide group. Preferably, each of Y ₁ , Y ₂ , Y ₃ and Y ₄ independently represents a single bond or an alkylene oxide group having 1 to 3 carbon atoms (ie, - (CH ₂ O) m -, - (CH ₂ OCH ₂ O) m- or - (CH ₂ OCH ₂ OCH ₂ O) m-, where m is an integer of 1 or more and 12 or less, and more preferably a single bond.

In the formula (5), n is preferably an integer of 1 or more and 3 or less, more preferably 1 or 2, from the viewpoint of availability.

The above component (B) may be used singly or in combination of two or more. The component (B) may be a commercially available product or a synthetic product.

Specific examples of the component (B) include at least one member selected from the group consisting of pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (Meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, and the like. Among them, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate or dipentaerythritol hexa (meth) acrylate is preferable as the component (B) from the viewpoint of the folding resistance.

A-TMM-3, A-TMM-3L, A-TMM-3LM-N, ATM-35E, A-TMMT, A-9550 and A- (Trade name) manufactured by Nippon Kayaku Co., Ltd.), PETIA, PETRA, EBECRYL (registered trademark) 40, EBECRYL (registered trademark) 180, DPHA (DAICEL- ALLNEX LTD. PE-3A, Light Acrylate (registered trademark) PE-4A, Light Acrylate (registered trademark) DPE-6A (Kyoeisha Kagakaku Co., Ltd.), Miramer M340, Miramer M4004, Miramer M600 ), And the like.

The content of the pentaerythritol compound (B) in the pressure-sensitive adhesive composition is from 0 part by mass to 0.05 part by mass with respect to 100 parts by mass of the main component (A). In a pressure-sensitive adhesive composition containing no pentaerythritol compound (B), it is difficult to achieve sufficient durability and folding resistance. On the other hand, when the content of the pentaerythritol compound (B) in the composition exceeds 0.05 part by mass, even if the glass transition temperature of the pressure-sensitive adhesive composition after curing is -70 ° C or higher and -60 ° C or lower, ) Is not satisfactory in terms of the folding resistance at the time of use. The content of the pentaerythritol compound (B) in the pressure-sensitive adhesive composition is preferably from 0.0005 parts by mass to 0.05 parts by mass, more preferably from 0.005 parts by mass to 0.04 parts by mass, relative to 100 parts by mass of the main component (A) Or less. On the other hand, when two or more compounds are employed as the pentaerythritol compound (B), the content of the pentaerythritol compound (B) in the pressure sensitive adhesive composition is the total amount of two or more compounds.

[Photopolymerization initiator (C)]

In another preferred embodiment of the present invention, the pressure-sensitive adhesive composition contains 0 parts by mass or more and 5 parts by mass or less, and 0.1 parts by mass or more and 5 parts by mass or less, 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, the final copolymerization reaction is performed to facilitate the formation of an adhesive film. As the photopolymerization initiator (C), 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 0.2 parts by mass or more and 2 parts by mass or less.

[Silane coupling agent (D)]

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

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 (D) used in the pressure-sensitive adhesive composition of the present invention is not particularly limited, and examples thereof include 3-glycidoxypropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, tri Methyltrimethoxysilane, methylmethoxysilane, n-propyltrimethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane, n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane , Phenyltrimethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (? -Methoxyethoxy) silane ,? - (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane,? -glycidoxypropyltrimethoxysilane,? -glycidoxypropyltriethoxy Silane,? -Methacryloxypropyl methacrylate Methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- - (aminoethyl) -? - aminopropylmethyl dimethoxysilane, N -? - (aminoethyl) -? - aminopropyltrimethoxysilane, N -? - Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltrimethoxysilane,? -Chloropropyltrimethoxysilane,? -Mercaptopropyltri Methoxysilane,? -Mercaptopropylmethyldimethoxysilane, bis- (3- [triethoxysilyl] propyl) tetrasulfide,? -Isocyanate propyltriethoxysilane, and the like. 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 (D), 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 (D) may be used singly or in combination of two or more kinds.

When the pressure-sensitive adhesive composition of the present invention contains the silane coupling agent (D), the content thereof is preferably not less than 0 parts by mass and not more than 10 parts by mass, and not less than 0.0001 parts by mass and not more than 10 parts by mass with respect to 100 parts by mass of the main component (A) More preferably 0.001 part by mass or more and 5 parts by mass or less, and particularly preferably 0.01 part by mass or more and 3 parts by mass or less. With such a range, 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 containing at least one of the component (a-2) and the component (a ') as a solvent. Examples of the solvent used in the polymer syrup include the components (a-1), (a-2) and (a ') exemplified above. Accordingly, the pressure-sensitive adhesive composition of the present invention may contain at least one of the components (a-1), (a-2) and (a ') as a solvent in the composition.

[Other ingredients 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, when the curable compound in the main component (A) is the monomer (1), the component (a-1), the component (a-2), the component (B) a ') component, a photopolymerization initiator (C), a silane coupling agent (D), a solvent, and other additives.

(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- (C), a silane coupling agent (D), a solvent, and other additive components, if necessary, in addition to the components (A ') and (B').

When the curable compound in the main component (A) is the polymer (3), the copolymer (a-3) or its solution, the component (B) and the photopolymerization initiator (C) (D), a solvent, and other added components.

The method of adding the component (B) according to the present invention is not particularly limited. For example, the component (B) is obtained by dissolving the component (B) prepared by dissolving the component (B) in at least one of the component (a-1) and the component (a- It may be added and adjusted so as to have a desired content with respect to the total amount of the compound.

[Adhesive film]

The adhesive film is, in terms of bending resistance at a high temperature, the storage elastic modulus at 85 ℃ after curing G '(85) of the present invention is preferably 1 × 10 ⁴ ㎩ than ⁴ × 10 4 ㎩ less, 2.0 × 10 ⁴ to 3.5 x 10 ⁴ Pa and 2.2 x 10 ⁴ to 3.5 x 10 ⁴ Pa are more preferable. Within this range, bending resistance at high temperatures may be good.

The pressure-sensitive adhesive film of the present invention preferably has a storage elastic modulus G '(-20) at -20 캜 after curing of less than or equal to 1 x 10 ⁴ Pa and less than 5 x 10 ⁴ Pa in view of bending resistance at low temperatures, is more than ⁴ × 10 to 3.5 × 10 ⁴ ㎩ ㎩ or less, 1.5 × 10 ⁴ or more to 3.2 × 10 ⁴ ㎩ ㎩ or less is more preferable. Within this range, bending resistance at high temperatures may be good.

The pressure-sensitive adhesive film of the present invention preferably has a storage elastic modulus G '(-20) at -20 ° C: a storage modulus G' (85) at 85 ° C of 1: 0.2 to 1: 1, 1: 1 &lt; / RTI &gt; 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 pressure-sensitive adhesive film of the present invention may have a glass transition temperature of -70 ° C or higher and -60 ° C or lower, but it is preferably -66 ° C or higher and -60 ° C or lower and -65 ° C or higher and -60 ° C or lower from the viewpoint of folding resistance at low temperatures .

The adhesive film of the present invention may have an adhesive force of 5 N / 25 mm or more, preferably 5 N / 25 mm or more and 15 N / 25 mm at 23 ° C. Within the above range, there may be an effect that peeling from the adherend does not occur even under low temperature, high temperature and high temperature and high humidity conditions.

The adhesive film of the present invention was evaluated for haze (H ₀ , unit:%) measured at 23 ° C and 55% RH on a test piece having a three-layer structure in which a glass, an adhesive film and a PET film were sequentially laminated, (H - H ₀ ) / H _{2 O} from the haze (H) measured by the same method after 2 hours from the time when the sample was taken out under the environment of 23 ° C. and 55% } X 100 (%) is less than 2%, preferably 0% or more and 1% or less. Within this range, the reliability of the display device can be improved because the adhesion of the adhesive film is highly reliable.

The pressure-sensitive adhesive film of the present invention is a pressure-sensitive adhesive film comprising a laminate on which a conductive PET film, an ITO film and a conductive tape are sequentially laminated, a PET film on which an adhesive film is formed, The resistance value (resistance value immediately after attaching) measured after standing for 24 hours in the environment and the same test piece were left for 24 hours under the environment of 23 ° C and left for 7 days under the environment of 60 ° C and 95% RH. , The resistance value after leaving for 7 days at 95% RH) is less than 120% after leaving for 7 days at 60 DEG C and 95% RH relative to the resistance value immediately after the application, the corrosion resistance against the metal adhered to the adhesive film can be increased have.

The pressure-sensitive adhesive film of the present invention was obtained by cutting a polarizing plate having a 50 占 퐉 thick adhesive film on a polyimide film (thickness: 0.7 mm) on which a silicon nitride film (thickness: 50 nm) was formed and adhering the piece to a width x length (70 mm x 140 mm) When a bending test was performed at a speed of 30 cycles per minute with one cycle in which a longitudinal length (140 mm) of a specimen was inserted into an inner diameter (diameter) of 6 mm and bent at 180 °, the bending conditions i) 23 ° C. and 55% relative humidity ii) 85 ° C, iii) 60 ° C and 95% relative humidity, iv) the minimum number of times of lifting or bubbling during bending at -20 ° C is 100,000 or more, preferably 100,000 to 200,000 times . Within this range, it can be used in a flexible display.

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 carried out as the curing treatment ) Component, (a-2) component and / or copolymer (a-3 and optionally added component (a ')) to the 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), the curing treatment is typically carried out by drying (heating and drying), crosslinking or the like 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. When the main component (A) is in the form of the above-mentioned (3) (a form in which the curable compound is only a polymer) composed of the copolymer (a-3), the curing of the pressure sensitive adhesive composition can be performed by the above-

Further, 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. For example, after further drying at a temperature of 40 ° C or more and less than 100 ° C for at least 0.1 minute and at most 10 minutes, further drying treatment may be performed at 100 ° C or more and 200 ° C or less for 1 minute or more and 20 minutes or less. This makes it possible to prevent peeling, peeling, and cracking caused by rapid volatilization of the solvent.

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, ultraviolet rays having an illuminance of not less than 200 mW / cm ^{2 and not} more than 200 mW / cm ^{2 at a} wavelength of not less than 200 nm and not more than 400 nm are irradiated with light with an accumulated light quantity of not less than 200 mJ / cm ^{2 and not} more than 10000 mJ / cm ² , .

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.

[Adhesive sheet]

In one aspect of the present invention, there is also provided a pressure-sensitive adhesive sheet comprising a pressure-sensitive 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 applicable to various applications and can be used, for example, in optical members such as 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. That is, in one embodiment of the present invention, there is provided an optical member comprising an adhesive film formed by curing a pressure-sensitive adhesive composition according to the present invention.

The pressure-sensitive adhesive composition of the present invention may be used by directly applying the pressure-sensitive adhesive composition on one side or both sides of the optical member to form an adhesive film, or by previously forming an adhesive film on the release film and transferring the adhesive film to one side or both sides of the optical member . Since the pressure-sensitive adhesive composition of the present invention has excellent durability, lifting and peeling of the pressure-sensitive adhesive film by heat treatment and high-humidity treatment can be prevented.

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 apparatus. Examples of the image display device include a liquid crystal display device, an organic EL display device, a plasma display (the above-mentioned curved surface display made of a polymer or a flexible display, and the like.

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 in the production of various films or sheets used in liquid crystal display devices such as flexible displays, electroluminescence devices, and the like, and can be used in these technical fields.

[ 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. All parts and percentages in the examples are based on mass. The conditions for leaving the room at room temperature, which are not specifically defined below, are all 23 ° C and 55% RH.

<Viscosity>

The temperature of the main component (A) in the glass bottle was adjusted to 25 캜 and measured by a B-type viscometer.

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

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

· Analyzer: Toso Co., Ltd., HLC-8120GPC

· Column: Toso products, G7000H _XL + GMH _XL + GMH _XL

· 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 Example 1]

&Lt; Preparation of main component (A-1) >

The main component (A-1) was prepared as shown below.

The reaction was carried out in a reaction box equipped with four black lights (FL20SBL manufactured by Sankyo Denki Co., Ltd., emission wavelengths of not less than 315 nm and not more than 400 nm) provided on four sides of a UV lamp in an environment shielding ultraviolet rays from the outside.

In a 2-liter four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introducing tube and a cooling tube, 64 parts by mass of 2-ethylhexyl acrylate (2EHA), 2 parts by mass of 2-ethylhexyl-diglycol acrylate 15 parts by mass of 2-hydroxyethyl acrylate (HEA), 1 part by mass of polymethyl methacrylate macromonomer (AA-6), 20 parts by mass of 2,2-dimethoxy-1 , And 0.005 parts by mass of 2-diphenylethane-1-one (Irgacure (registered trademark) 651 BASF Japan Co., Ltd.) were mixed. Thereafter, air in the flask was heated to 30 DEG C while replacing nitrogen with nitrogen. In order to initiate polymerization, light of 4 mW / cm ² was irradiated by black light. After the initiation of the reaction, the temperature of the reaction system was elevated, but at the stage where the rise of the reaction temperature from the start was 10 占 폚, the irradiation of black light was stopped and air was introduced into the flask by an air pump to forcibly stop the reaction. As a result, the main component (A-1) containing the copolymer (a-3-1) (polymerization rate: 8%) in which a part of the monomer component was polymerized was obtained. The viscosity of the main component (A-1) was 1000 mPa 占 퐏 and the weight average molecular weight (Mw) of the copolymer (a-3-1) was 1.8 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%.

[Production Example 2]

&Lt; Preparation of main component (A-2) >

(2EHA), 15 parts by mass of methoxyethyl acrylate (MEA), 2 parts by mass of 2-hydroxyethyl acrylate (2-hydroxyethyl acrylate) (HEA), 3 parts by mass of acryloyl morpholine (ACMO) and 0.1 part by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator were introduced together with 100 parts by mass of ethyl acetate, and gently stirred While nitrogen gas was introduced to replace the nitrogen. Thereafter, the polymerization reaction was carried out for 5 hours while maintaining the liquid temperature in the flask at around 55 캜. After completion of the polymerization reaction, 300 parts by mass of ethyl acetate was added and diluted to obtain the main component (A-2) containing the copolymer (a-3-2) (polymerization degree 90%, solid content 18% by mass). The viscosity of the main component (A-2) was 3500 mPa.s and the weight average molecular weight (Mw) of the copolymer (a-3-2) was 1.4 million.

[Production Example 3]

&Lt; Preparation of main component (A-4) >

80 parts by mass of 2-ethylhexyl acrylate (2EHA), 19 parts by mass of methoxyethyl acrylate (MEA), and 4 parts by mass of 4-hydroxyethyl methacrylate were added to a four-necked flask equipped with a stirring wing, a thermometer, -Hydroxybutyl acrylate (4HBA) as a polymerization initiator and 0.1 part by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator together with 100 parts by mass of ethyl acetate, and while introducing nitrogen gas with gentle stirring Nitrogen substitution. Thereafter, the polymerization reaction was carried out for 5 hours while maintaining the liquid temperature in the flask at around 55 캜. Subsequently, while maintaining the temperature, 320 parts by mass of 2-ethylhexyl acrylate (2EHA), 76 parts by mass of methoxyethyl acrylate (MEA), 4 parts by mass of 4-hydroxybutyl acrylate (4HBA) Ethyl acetate was distilled off to obtain a main component (A-4) containing the copolymer (a-3-3) (polymerization degree 90%, solid content 18 mass%). The viscosity of the main component (A-4) was 4000 mPa 占 퐏 and the weight average molecular weight (Mw) of the copolymer (a-3-3) was 1.5 million.

[Production Examples 4 to 10]

(A-5) to (A-11) were obtained in the same manner as in Production Example 1, except that the kinds or the ratios of the monomers for preparing the main component (A) were changed as shown in Table 1, ) Was prepared. Mw (weight average molecular weight) of the copolymers (a-3-4) to (a-3-10) contained in the main components (A-5) to (A-11) are as shown in Table 1.

2EHA 2-ethylhexyl acrylate
(Product of Nihon Shokubai Co., Ltd., homopolymer Tg -65 캜) MEA Methoxyethyl acrylate
(Product of Nihon Shokubai Co., Ltd., homopolymer Tg -50 ° C) EHDG-AT 2-ethylhexyl-diglycol acrylate
(Manufactured by Kyoeisha Kakaku Corporation, homopolymer Tg -67 ° C) EC-A Ethoxy diethylene glycol acrylate
(Manufactured by Kyoeisha Kakaku Corporation, homopolymer Tg -70 ° C) HEA 2-hydroxyethyl acrylate
(Manufactured by Nihon Shokubai Co., Ltd., homopolymer Tg -15 ° C) 4HBA 4-hydroxybutyl acrylate
(Manufactured by Osaka Yuki Kagakuko Co., Ltd., homopolymer Tg -40 ° C) HEAA Hydroxyethyl acrylamide
(Product of KJ Chemicals, homopolymer Tg 98 ° C) AA-6 Polymethyl methacrylate macromonomer
(Product of TOAGOSEI CO., Homopolymer Tg 105 DEG C, Mn = 6000) NVP N-vinyl-2-pyrrolidone
(Product of Nihon Shokubai Co., Ltd., homopolymer Tg: 86 ° C) ACMO Acrylic Sunset Pauline
(Product of KJ Chemicals, homopolymer Tg 145 DEG C) AA Acrylic acid
(Manufactured by Nihon Shokubai Co., Ltd., homopolymer Tg 106 DEG C)

The homopolymer Tg (excluding EHDG-AT and NVP) is a catalog value of each maker. The homopolymers Tg of EHDG-AT and NVP are values determined by the DSC method according to JIS K7121 (1987).

The glass transition temperature of the copolymer (a-3) is a value calculated from the monomer units constituting each main component and the ratio thereof according to the following FOX formula.

The theoretical glass transition temperature determined from the formula of FOX agrees well with the measured glass transition temperature determined by differential scanning calorimetry (DSC) or dynamic viscoelasticity.

[Example 1]

(Preparation of pressure-sensitive adhesive composition)

(Hereinafter referred to as &quot; A-DPH &quot;) was added to 100 parts by mass of the main component (A-1) obtained in Production Example 1, , 0.3 parts by mass of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure (registered trademark) 651 BASF Japan Co., Ltd.) Degassed to obtain a photopolymerizable pressure-sensitive adhesive composition.

(Formation of adhesive film)

Next, this photopolymerizable pressure-sensitive adhesive composition was coated on one side of a release film (polyethylene terephthalate (PET) film having a thickness of 50 占 퐉 and subjected to silicone treatment, product of Mitsubishi Kagaku Polyester Film, MRF50) Respectively. By attaching another release film on the coating film, a release film was placed above and below the coating film of the pressure-sensitive adhesive composition to seal it in a sandwich form. Thereafter, the pressure sensitive adhesive composition was cured by irradiating an illuminance of 5 mW / cm ² and an accumulated light quantity of 1500 mJ / cm ² with a black light (FL20SBL manufactured by Sankyo Denki Co., Ltd., emission wavelength of 315 nm to 400 nm) to form a colorless transparent pressure sensitive adhesive film To obtain a pressure-sensitive adhesive sheet.

[Example 2]

(Preparation of pressure-sensitive adhesive composition)

0.03 parts by mass of A-DPH was added to 100 parts by mass of the main component (A-2) obtained in Production Example 2, followed by mixing and defoaming to obtain a pressure-sensitive adhesive composition.

(Formation of adhesive film)

Next, this pressure-sensitive adhesive composition was applied onto one side of a release film (polyethylene terephthalate (PET) film having a thickness of 50 탆 and subjected to silicone treatment, product of Mitsubishi Kagaku Polyester Film, MRF50) And dried at 80 캜 for 3 minutes. Thereafter, the film was dried at 120 DEG C for 10 minutes to form an adhesive film. Thereafter, in the same manner as in Example 1, another release film was attached to the adhesive film to obtain a pressure-sensitive adhesive sheet.

[Example 3]

(Preparation of pressure-sensitive adhesive composition)

0.04 parts by mass of A-DPH was added to the main component (A-3) composed of 65 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of 2-ethylhexyl-diglycol acrylate and 15 parts by mass of 2-hydroxyethyl acrylate, And 0.3 part by mass of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure (registered trademark) 651 BASF Japan Co., Ltd.) were added and mixed and defoamed to obtain a photopolymerizable pressure- .

(Formation of adhesive film)

Next, this photopolymerizable pressure-sensitive adhesive composition was coated on one side of a release film (polyethylene terephthalate (PET) film having a thickness of 50 占 퐉 and subjected to silicone treatment, product of Mitsubishi Kagaku Polyester Film, MRF50) Respectively. By attaching another peeling film on the coated surface, a peeling film was placed above and below the coated film of the pressure-sensitive adhesive composition to seal it in a sandwich form. Thereafter, the pressure-sensitive adhesive composition was cured by irradiating an illuminance of ² mW / cm ² and an accumulated light quantity of 7200 mJ / cm ² with a black light (FL20SBL manufactured by Sankyo Denki Co., Ltd., emission wavelength of 315 nm or more and 400 nm or less) to form a colorless transparent adhesive film To obtain a pressure-sensitive adhesive sheet.

[Examples 4 to 7 and Comparative Examples 1 to 8]

The kind and amount of the pentaerythritol compound (B), the kind and amount of the photopolymerization initiator (C), the type of the silane coupling agent (D) and the other additives (E) A pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet were prepared in the same manner as in Example 1, except that the pressure-

<Gel fraction>

The gel fractions of the pressure-sensitive adhesive compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 9 were measured. The gel fraction was determined by the following method. That is, about 0.1 g of the pressure-sensitive adhesive composition was weighed and the weight W1 (g) was measured. This was taken in a sample bottle, and about 30 g of ethyl acetate was added and left for 24 hours. The contents of the sample bottle after the lapse of a predetermined time were measured by filtration through a 200 mesh stainless steel wire netting (the weight of the membrane was W2 (g)) and the weight W3 (g) of the whole wire netting and the residue dried at 90 DEG C for 1 hour Respectively. The gel fraction was calculated from the measured values by the following formula (2).

&Lt; Glass transition temperature after curing of pressure-sensitive adhesive composition >

Using the pressure-sensitive adhesive compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 9, the glass transition temperature after curing was measured. That is, the measurement was carried out by the DSC method according to JIS K7121 (1987).

&Lt; Measurement of storage elastic modulus &

The pressure-sensitive adhesive films prepared in each of the Examples and Comparative Examples were measured at a temperature ranging from -30 ° C to 150 ° C using a viscoelasticity measuring apparatus (product of Mitsubishi Electric Co., Ltd., model: MCR300) Was measured. More specifically, the produced pressure-sensitive adhesive film was laminated with a thickness of 400 탆 and cut into a size of 8 mm in diameter to obtain a measurement sample. Thereafter, the measurement specimen was set in a parallel plate jig, and a frequency of 1 kPa (rad. S ^-1 ), a normal force of 3 N, a heating rate of 5 ° C / min Lt; / RTI &gt;

&Lt; Preparation of thin polarizing plate &

A polyvinyl alcohol film having a thickness of 20 占 퐉 was stretched to 3 times while dyeing in a 0.3% by mass iodine solution at 30 占 폚 for 1 minute between rolls having different velocity ratios. Thereafter, the substrate was immersed in an aqueous solution containing 60% by mass of 4% by mass of boric acid and 10% by mass of potassium iodide for 0.5 minutes to stretch the total draw ratio up to 6 times. Subsequently, the substrate was washed by immersing in an aqueous solution containing 1.5% by mass of potassium iodide at 30 DEG C for 10 seconds, and then dried at 50 DEG C for 4 minutes to obtain a polarizer. A polycarbonate film having a thickness of 20 mu m and a retardation film (WRS, manufactured by Teijin Chemicals Co., Ltd.) having a thickness of 50 mu m (1/4 wave plate, manufactured by Teijin Chemicals Co., Ltd.) were coated on one surface of the polarizer with a polyvinyl alcohol- To produce a thin polarizing plate having a total thickness of 77 m.

(Fabrication of conductive layer and protective layer)

70 parts by mass of ultrapure water (Ultrapure Water, manufactured by Wako Pure Chemical Industries, Ltd.) per 30 parts by mass of a nanowire dispersion solution (ClearOhm Ink-A AQ manufactured by Cambrios, USA) Product, ClearOhm SFT-D) was added in an amount of 0.12 parts by mass to prepare a coating layer for forming a conductive layer. On the phase difference film surface of the thin polarizing plate, a coating layer for forming a conductive layer was applied by a die coating method so that the coating amount of the solid content was 1 g / m ² , and dried at 80 캜 to form a conductive layer.

95 parts by mass of ethyl acetate was added per 5 parts by mass of acrylic resin-based paint (manufactured by Chukogaku Co., Ltd., PHOLUCID (registered trademark) No. 420C resin concentration 50% by weight) Lt; / RTI &gt; On the conductive layer, a coating for forming a protective layer was applied by a die coating method so that the thickness of the protective layer (thickness after curing) became 210 nm, dried at 80 占 폚 and irradiated with ultraviolet rays (LH10-70UV lamp manufactured by Fusion UV Systems Japan Co., (200 mJ / cm &lt; ² &gt;) to form a protective layer.

&Lt; Preparation of Polarizer with Adhesive Film >

Corona treatment was performed on the side of the retardation film forming the pressure-sensitive adhesive film of the polarizing plate with a corona discharge amount of 80 [W / min / m ² ]. Next, the release film was peeled off from one side of the pressure-sensitive adhesive sheet to expose the pressure-sensitive adhesive film, and the pressure-sensitive adhesive film was transferred so as to contact the WRS. The release film on the opposite side to the polarizing plate was peeled from the adhesive film to produce a polarizing plate with a pressure-sensitive adhesive film.

<Durability Test>

A polyimide film (thickness 0.7 mm) having a silicon nitride (SiN _x ) film (thickness: 50 nm) on the outermost surface was used as a substitute for the flexible panel.

A polarizing plate sample with an adhesive film was made to have a size of 5 inches and attached to a polyamide film using a laminator. Then, the sample was autoclaved at 50 DEG C and 0.5 MPa for 15 minutes to completely adhere the sample to the polyamide film. Thereafter, the sample was sandwiched between the glass plates so that the inside diameter (diameter) could be maintained at 6 mm. (1) treatment at 85 캜 for 500 hours (heating test) was carried out on each sample subjected to such treatment. (2) Further, treatment was conducted for 500 hours in an atmosphere of 60 DEG C and 95% RH (humidification test). (3) Further, after conducting 300 cycles (heat shock test) in an environment of 85 ° C and -40 ° C for 1 cycle for 1 hour, the appearance of the polarizing plate and the polyamide film was evaluated according to the following criteria And evaluated visually.

?: No apparent changes such as foaming, peeling, peeling, cracking, etc. were observed.

?: There is peeling, foaming or cracking at the end, but there is no practical problem unless it is used for a special purpose.

X: Significant peeling at the end, causing a problem in practical use.

In the tests (1), (2) and (3), samples were prepared and tested independently.

<Adhesion>

Samples similar to those used in the durability test were newly prepared and cut to a width of 25 mm and a length of 100 mm, respectively. Then, the sample was autoclaved at 50 DEG C and 5 atm for 15 minutes to adhere the sample to the polyamide film. Thereafter, the film was allowed to stand in an atmosphere of 23 ° C and 55% RH for 1 hour, and the adhesive strength was measured.

The adhesive strength was measured in accordance with JIS Z0237 (trade name) at a peel angle of 180 deg. And a peel rate of 300 mm / min under conditions of 23 deg. C and relative humidity of 55% RH in a tensile tester (Tensilon universal material tester STA-1150 manufactured by Orientech Co., : The adhesive strength (N / 25 mm) at the time of peeling off the film was measured according to the method of testing the adhesive tape and the adhesive sheet of 2009.

<Autoclave suitability>

The polarizing plates with the adhesive films obtained in the above Examples and Comparative Examples were affixed to a glass plate to prepare samples for evaluation. Next, the sample for evaluation was placed in an autoclave and subjected to an autoclave treatment at 50 DEG C and 0.5 MPa for 15 minutes. Thereafter, the evaluation sample taken out from the autoclave was visually observed to confirm the presence of bubbles. Evaluation was made by o when no bubbles were observed in the evaluation sample after the autoclave treatment and by X when the bubbles were observed in the evaluation sample after the autoclave treatment.

<Humidity reliability test>

The release film was peeled off from one side of the pressure-sensitive adhesive sheet produced in each of the Examples and Comparative Examples, and transferred to a PET film (A4 100 thickness, 100 탆 haze, 0.6% manufactured by Toyobo Co., Ltd.). Next, the PET film to which the pressure-sensitive adhesive sheet was transferred was cut into a size of 50 mm in width × 50 mm in length, and the other release film was peeled off, and the pressure-sensitive adhesive layer side was attached to the glass plate. As a result, a test piece having the constitution of &quot; glass / adhesive film / PET film &quot; was produced.

The haze of the test specimen at 23 캜 and 55% RH was measured (H ₀ ) using a haze meter (NDH5000W manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.). The test pieces were stored for 3 days under an environment of 60 占 폚 and 95% RH, and immediately after they were taken out under an environment of 23 占 폚 and 55% RH, the haze (H) was measured after 2 hours from the removal. The evaluation was made as follows. When the value calculated by {(H - H ₀ ) / H ₀ } × 100 (%) was less than 2%

&Lt; Metal corrosion inhibition / prevention property >

The release films were peeled from one side of the pressure-sensitive adhesive sheet prepared in the examples and the comparative examples, transferred to a PET film (A4 100 thickness, 100 m, manufactured by Toyobo Co., Ltd.), cut into a size of 20 mm width x 50 mm length, (11)).

As shown in Fig. 1, both ends of a conductive PET film 12 (ELECRYSTA V-150FLC5, product of Nitto Denko Co., Ltd. (size: length 70 mm x width 25 mm) , And the adhesive film side of the test piece 11, on which the separator was peeled off, was bonded to the conductive surface (the ITO film formation surface 121 side). This was left for 24 hours under an environment of 23 占 폚 and left for 7 days under an environment of 60 占 폚 and 95% RH. The ratio (%) of "resistance value after leaving for 7 days at 60 占 폚 and 95% RH" (Resistance value after leaving for 7 days at 60 占 폚 and 95% RH) / (resistance value immediately after the attachment) x 100 (%)]. The resistance value was measured by attaching electrodes to the conductive tapes 122 at both ends using "Multi-tester SR-18D" manufactured by SANWA ELECTRIC KYOTO CO., LTD. When the ratio of the resistance value after 60 days and 95% RH for 7 days to the resistance value immediately after the application is less than 120%, the corrosion resistance is evaluated as good (good) " As a result of performing the same test using only a conductive PET film not pasted with the adhesive sheet as the blank, the ratio of the "resistance value after leaving for 7 days at 60 ° C and 95% RH" to "the resistance value immediately after the attachment" was less than 120%.

<Folding resistance>

(Length x length, 70 mm x 140 mm) as used in the above durability test was folded with a bending tester (manufactured by TESTER SANKYO CO., LTD.) So that the length (140 mm) Bending and 180 ° opening were repeated for 100,000 cycles at a rate of 30 cycles per minute. The test was conducted under an atmosphere of 23 ° C and 55% RH at 85 ° C, 60 ° C and 95% RH or at -20 ° C, respectively. The appearance of the polarizing plate and the polyamide film after the test was visually evaluated based on the following criteria.

?: No apparent changes such as foaming, peeling, peeling, cracking, etc. were observed.

?: There is peeling, foaming or cracking at the end, but there is no practical problem unless it is used for a special purpose.

X: Significant peeling at the end, causing a problem in practical use.

B-1 Dipentaerythritol hexaacrylate
(NK Ester A-DPH manufactured by Shin Nakamura Kagaku Kyoko Co., Ltd.) B-2 Pentaerythritol triacrylate
(Light Acrylate (registered trademark) PE-3A manufactured by Kyoeisha Kagaku Co., Ltd.) B-3 Pentaerythritol tetraacrylate
(Light Acrylate (registered trademark) PE-4A manufactured by Kyoeisha Kagaku Co., Ltd.) C-1 2,2-dimethoxy-1,2-diphenylethan-1-one
(Irgacure (registered trademark) 651 manufactured by BASF Japan Co., Ltd.) C-2 1-hydroxycyclohexyl phenyl ketone
(Irgacure (registered trademark) 184 manufactured by BASF Japan Co., Ltd.) D-1 3-glycidoxypropyltriethoxysilane
(KBE-403 manufactured by Shin-Etsu Chemical Co., Ltd.) E-1 Polyethylene glycol (600) diacrylate
(SR610 manufactured by Arcema Co., Ltd.) E-2 Trimethylolpropane triacrylate
(Shin-Nakamura Kagaku Kyoko Co., Ltd. product A-TMPT)

11: Test piece 111: PET film,
112: adhesive sheet, 12: conductive PET film,
121: Conductive PET film (ITO film forming surface)
122: Conductive tape

Claims (21)

As the pressure-sensitive adhesive composition,
100 parts by mass of a main component (A) comprising a curable compound; And
0 to less than 0.05 part by mass of a pentaerythritol compound (B)
The main component (A) is a mixture of a (meth) acrylic acid ester monomer (a-1) and a hydroxyl group-containing (meth) acrylic monomer (a-2); And a structural unit (2) derived from the (meth) acrylic acid ester monomer (a-1) and the hydroxyl group-containing (meth) acrylic monomer (a-2) (a-3), &lt; / RTI &gt;
Wherein the glass transition temperature after curing is from -70 占 폚 to -60 占 폚.
The pressure-sensitive adhesive composition according to claim 1, wherein the content of the hydroxyl group-containing (meth) acrylic monomer (a-2) is 0.1% by mass or more and 30% by mass or less based on the total amount of the main component (A).
The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the content of the (meth) acrylic ester monomer (a-1) is 70% by mass or more based on the total amount of the main component (A).
The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the content of the copolymer (a-3) is 5% by mass or more and 25% by mass or less with respect to the total amount of the main component (A).
3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the copolymer (a-3) has a weight average molecular weight of not less than 1,000,000 and not more than 2.5 million.
The positive resist composition according to claim 1 or 2, wherein the copolymer (a-3) comprises the (meth) acrylic ester monomer (a-1) and the hydroxyl group- Wherein the pressure-sensitive adhesive layer is formed by polymerization of ultraviolet rays of a reaction liquid.
The positive resist composition according to claim 1 or 2, wherein the copolymer (a-3) comprises the (meth) acrylic ester monomer (a-1) and the hydroxyl group- And then polymerizing the solution by solution polymerization of the reaction solution.
The pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising 0.1 part by mass to 5 parts by mass of a photopolymerization initiator (C).
The positive resist composition according to claim 1 or 2, wherein the (meth) acrylic acid ester monomer (a-1) is at least one compound selected from the group consisting of 2-ethylhexyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) (Meth) acrylate, and diethylene glycol (meth) acrylate.
The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the pressure-sensitive adhesive composition has a gel fraction of 70% or more and 90% or less.
The positive resist composition according to claim 1 or 2, wherein the main component (A) further comprises at least one of a (meth) acrylic monomer having (a'-1) amide group and a macromonomer containing (a'- , A pressure-sensitive adhesive composition.
A main component (A) comprising a curable compound; And
(Meth) acrylic ester monomer (a-1) and a hydroxyl group-containing (meth) acrylic monomer (a-2) in the presence of a Including,
A glass transition temperature of -70 DEG C or higher and -60 DEG C or lower,
A polarizing plate with a thickness of 50 m was affixed to a polyimide film (thickness: 0.7 mm) on which a silicon nitride film (thickness: 50 nm) was formed and cut into a width x length (70 mm x 140 mm) When the bending was performed at -20 ° C at a rate of 30 cycles per minute by bending and spreading at 180 ° with a vertical length (140 mm) so that the inner diameter (diameter) became 6 mm, the minimum number of times of lifting or bubbling was 100,000 or more , An adhesive film.
The adhesive film according to claim 12, wherein the adhesive film has an adhesive force of 5 N / 25 mm or more at 23 캜.
The method according to claim 12, wherein haze (H ₀ , unit:%) measured at 23 ° C and 55% RH on a test piece having a three-layer structure in which the glass, the adhesive film and the PET film are sequentially laminated, (H - H ₀ ) / H ₀ } × (H - H ₀ ) / H ₂ ) was obtained from the haze (H) measured in the same manner immediately after removal from the environment at 23 ° C. and 55% And the value calculated as 100 (%) is less than 2%.
The method of claim 12, wherein the adhesive film, the storage elastic modulus at 85 ℃ G '(85) is 1 × 10 ⁴ ㎩ than ⁴ × 10 4 ㎩ lower than the adhesive film.
The pressure-sensitive adhesive film according to claim 12, wherein the pressure-sensitive adhesive film has a storage elastic modulus G '(-20) at 20 캜 of 1 x 10 ⁴ Pa or more and less than 5 x 10 ⁴ Pa.
The adhesive film according to claim 12, wherein the adhesive film has a ratio of a storage elastic modulus G '(-20) at -20 캜 to a storage elastic modulus G' (85) at 85 캜 of 1: 0.2 to 1: film.
13. The method according to claim 12, wherein the main component (A) is a mixture of the (meth) acrylic acid ester monomer (a-1) and the hydroxyl group-containing (meth) acrylic monomer (a-2) And a structural unit (2) derived from the (meth) acrylic acid ester monomer (a-1) and the hydroxyl group-containing (meth) acrylic monomer (a-2) (a-3). &lt; / RTI &gt;
The adhesive film according to claim 12, wherein said main component (A) further comprises at least one of a (meth) acrylic monomer having (a'-1) amide group and a macromonomer containing (a'-2) polymerizable functional group.
A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive film formed by curing the pressure-sensitive adhesive composition according to claim 1 or 2.
An image display apparatus comprising an adhesive film obtained by curing the pressure-sensitive adhesive composition according to any one of claims 1 to 12 or an adhesive film according to any one of claims 12 to 19.

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