TW201431999A - Adhesive composition, adhesive and adhesive sheet - Google Patents

Abstract

This invention provides an adhesive composition, adhesive and an adhesive sheet with the excellent durability even when being used for optical components such as polarizers. To address the aforesaid subject, as disclosed is an adhesive composition having a weight average molecular weight of 0.9 million to 3 million and comprising: as the monomer unit of the polymer, the (meth) acrylate ester polymer having monomers containing alicyclic structures (A); the active energy ray curable ingredient (B); and the silane coupler (C), which has a mercapto group as the functional group to react with an organic material.

Description

Adhesive composition, adhesive and adhesive sheet

The present invention relates to an adhesive composition, an adhesive (a material for curing the adhesive composition), and an adhesive sheet, and more particularly to an adhesive composition suitable for use as an optical member such as a polarizing plate. Adhesive and adhesive sheet.

In recent years, in various electronic devices, a touch panel having both a display device and an input means has been frequently used. The types of touch panels are mainly resistive, capacitive, optical, and ultrasonic. The resistive touch panel has an analog data resistor and a matrix resistor. The capacitive touch panel has a surface type and a projection type.

The touch panel of mobile electronic devices such as smart phones and tablet terminals that have recently attracted attention has mostly used projection type capacitive touch panels. As a projection type capacitive touch panel of the above-described mobile electronic device, for example, it has been proposed to laminate a liquid crystal display device (LCD), an adhesive layer, a transparent conductive film (indium tin oxide: ITO), and glass in order from bottom to top. A touch panel of a protective layer such as a substrate, a transparent conductive film (ITO), or a tempered glass.

As the optical member constituting the liquid crystal display device described above, a liquid crystal module is generally used. In the liquid crystal module, the alignment layer of the two transparent electrode substrates forming the alignment layer is generally disposed inside, and is disposed by spacers so as to form a predetermined interval, and the periphery thereof is sealed between the two transparent electrode substrates. Hold the components of the liquid crystal material. Usually, on the outer side of the two transparent electrode substrates in the liquid crystal module, the polarizing plates are bonded to the polarizing plates.

As the adhesive to be used in the touch panel, for example, the adhesive shown in Patent Document 1 is known. The binder contains, as a monomer unit, 0.2 parts by weight to 20 parts by weight of the carboxyl group-containing monomer, based on 100 parts by weight of the alkyl (meth) acrylate having an alkyl group having 4 to 14 carbon atoms. (meth) propylene-based polymer obtained by copolymerizing a component, and 100 parts by weight of a (meth) propylene-based polymer, containing 0.02 parts by weight to 2 parts by weight of a peroxide as a bridging agent, and containing an epoxy resin The bridging agent is 0.005 parts by weight to 5 parts by weight.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-242786

In the touch panel as described above, the use of a polarizing plate using a polycycloolefin protective film has recently increased, and the polarizing plate has been reduced in thickness as the mobile electronic device has been thinned in recent years. However, since the material of the polycycloolefin lacks the adhesiveness with the adhesive and the shrinkage of the thin polarizing plate is high, the conventional adhesive such as Patent Document 1 has low durability, and it is time-lapse or under high temperature conditions. Under hot and humid conditions, there is a problem that floating and peeling easily occur.

The present invention has been made in view of such circumstances, and it is an object of the invention to provide an adhesive composition, an adhesive, and an adhesive sheet which are excellent in durability when applied to an optical member such as a polarizing plate.

In order to achieve the above object, first, the present invention provides an adhesive composition characterized by having a weight average molecular weight of 900,000 to 3,000,000 and comprising: (meth) acrylate polymer (A) as a constituent polymerization The monomer unit of the substance contains a monomer having an alicyclic structure; an active energy ray-curable component (B); and a decane coupling agent (C) having a thiol group as a functional group reactive with an organic material.

When the adhesive composition according to the above invention (Invention 1) is cured, a plurality of active energy ray-curable components (B) are combined with each other to form a three-dimensional network structure, and it is presumed that the three-dimensional network structure has an alicyclic structure. The (meth) acrylate polymer (A) forms a entangled structure with a decane coupling agent (C) having a mercapto group. When the optical member such as a polarizing plate or an optical member such as a polycycloolefin or a transparent conductive film is used as an adherend, the adhesive agent obtained by curing the above-mentioned adhesive composition is excellent in durability.

In the above invention (Invention 1), it is more preferable to contain a bridging agent (D) (Invention 2).

In the above invention (Invention 1, Invention 2), the (meth) acrylate polymer (A) preferably contains 0.1% by mass to 30% by mass of the alicyclic ring as a monomer unit constituting the polymer. Monomeric structure (Invention 3).

In the above invention (Invention 1 to Invention 3), the alicyclic structure preferably contains a cyclohexyl skeleton, a dicyclopentadiene, an adamantane skeleton or an isobornyl skeleton (Invention 4).

In the above invention (Invention 1 to Invention 4), the (meth) acrylate polymer (A) further preferably contains 0.1% by mass to 10% by mass of a monomer having a hydroxyl group as a monomer unit constituting the polymer. Body (Invention 5).

In the above invention (Invention 1 to Invention 5), the above (meth) propylene The acid ester polymer (A) preferably contains no monomer having a carboxyl group as a monomer unit constituting the polymer (Invention 6).

In the above invention (Invention 1 to Invention 6), the active energy ray-curable component (B) is preferably a polyfunctional acrylate monomer having a molecular weight of less than 1,000 (Invention 7).

In the above invention (Invention 7), the above polyfunctional acrylate monomer preferably has a cyclic structure (Invention 8).

In the above invention (Invention 1 to Invention 8), the content of the active energy ray-curable component (B) in the adhesive composition is 100 parts by mass based on the (meth) acrylate polymer (A). It is preferably 1 part by mass to 30 parts by mass (Invention 9).

In the above invention (Invention 1 to Invention 9), the content of the decane coupling agent (C) in the adhesive composition is preferably 100 parts by mass based on 100 parts by mass of the (meth) acrylate polymer (A). It is 0.01 parts by mass to 5 parts by mass (Invention 10).

In the above invention (Invention 1 to Invention 10), the bridging agent (D) is preferably an isocyanate-based bridging agent (Invention 11).

In the above invention (Invention 1 to Invention 11), it is more preferred to contain a photopolymerization initiator (E) (Invention 12).

Secondly, the present invention provides an adhesive which is obtained by curing the above-mentioned adhesive composition (Invention 1 to Invention 12) by irradiation with an active energy ray (Invention 13).

Thirdly, the present invention provides a bonding sheet which is an adhesive sheet having a substrate and an adhesive layer, and the adhesive layer is composed of the above-mentioned adhesive (Invention 13) (Invention 14).

In the above invention (Invention 14), the substrate is preferably an optical member (Invention 15).

In the above invention (Invention 15), the optical member is preferably a polarizing plate (Invention 16).

In the above invention (Invention 15, Invention 16), the optical member preferably has a polycycloolefin film (Invention 17). In addition, the "polycycloolefin-based film" has a concept of "consisting only of a polycycloolefin film".

Fourthly, the present invention provides a bonding sheet comprising two release sheets and an adhesive layer for holding the release sheet in contact with the release faces of the two release sheets, the adhesive layer It is composed of the above-mentioned adhesive (Invention 13) (Invention 18).

When the adhesive composition of the present invention contains the components (A) to (C), the obtained adhesive has high durability and is suitably used for an optical member such as a polarizing plate.

1A, 1B‧‧‧bonding strips

11‧‧‧Adhesive layer

12,12a,12b‧‧‧ peeling film

13‧‧‧Substrate

Fig. 1 is a cross-sectional view showing an adhesive sheet according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a bonding sheet according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described.

[adhesive composition]

The adhesive composition (hereinafter referred to as "adhesive composition P") according to the present embodiment has a weight average molecular weight of 900,000 to 3,000,000, and constitutes a polymerization. The monomer unit of the substance contains a (meth) acrylate polymer (A), an active energy ray-curable component (B), and a decane coupling agent (C) having a thiol group as a functional group reactive with an organic material, preferably Further, the bridging agent (D) and/or the photopolymerization initiator (E) is contained, and the (meth) acrylate polymer (A) contains a monomer having an alicyclic structure (containing an alicyclic structural monomer). In the present specification, the term "(meth)acrylate" means both acrylate and methacrylate. The same is true for other similar terms. In addition, the concept of "copolymer" is also included in "polymer".

When the above-mentioned adhesive composition P is cured, a plurality of active energy ray-curable components (B) are combined with each other to form a three-dimensional network structure, and it is presumed that the (meth) acrylate having an alicyclic structure is formed on the three-dimensional network structure. The polymer (A) and the decane coupling agent (C) having a mercapto group form a entangled structure. In the optical member such as a polarizing plate, an optical member such as a polycycloolefin (for example, an optical member composed of a polycycloolefin film or a part of a polycycloolefin film) is used. When the transparent conductive film is used as an adherend, the transparent conductive film is excellent in durability.

(1) (meth) acrylate polymer (A)

The (meth) acrylate polymer (A) has a monomer having an alicyclic structure as a monomer unit constituting the polymer. Thereby, the obtained adhesive agent is an adhesive agent excellent in durability as mentioned above. This effect is considered to be due to the fact that the alicyclic structure has a strong affinity and interaction with the optical member or the transparent conductive film, and the adhesion is improved.

The ring of carbon atoms of the alicyclic structure may be a ring of carbon atoms of a saturated structure or a ring of carbon atoms containing an unsaturated bond. Moreover, the alicyclic knot The structure may be a monocyclic alicyclic structure or a polycyclic alicyclic structure such as a bicyclic ring or a tricyclic ring. The number of carbon atoms of the alicyclic structure is preferably 5 to 20, particularly preferably 6 to 15, and still more preferably 7 to 12.

Examples of the alicyclic structure include a cyclohexyl skeleton, a dicyclopentadiene skeleton, an adamantane skeleton, an isobornyl skeleton, a cycloalkane skeleton (cycloheptane skeleton, a cyclooctane skeleton, a cyclodecane skeleton, and cyclodecane). Skeleton, cycloundecane skeleton, cyclododecane skeleton, etc.), cyclic olefin skeleton (cycloheptene skeleton, cyclooctene skeleton, etc.), norbornene skeleton, norbornadiene skeleton, polycyclic skeleton (cubicane An alicyclic structure such as a skeleton, a basketane skeleton, a housane skeleton or the like, or a spiro skeleton. Among them, a cyclohexyl skeleton having a more excellent durability effect is preferable. An alicyclic structure of a dicyclopentadiene skeleton, an adamantane skeleton or an isobornyl skeleton.

The monomer having an alicyclic structure is preferably a (meth) acrylate monomer containing the above skeleton, and specific examples thereof include cyclohexyl (meth) acrylate and dicyclopentanyl (meth) acrylate. And adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, etc., among which, More excellent cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate or isobornyl (meth)acrylate can be exhibited. These may be used alone or in combination of two or more.

The (meth) acrylate polymer (A) preferably contains 0.1% by mass to 30% by mass of the monomer having an alicyclic structure as the monomer unit constituting the polymer, and particularly preferably contains 0.2% by mass. 25 mass %, More preferably, it is 0.5 mass % - 20 mass %. Containing alicyclic structural monomers When the amount is less than 0.1% by mass, it is difficult to obtain the above-described effect of improving durability. When the content of the alicyclic structure-containing monomer exceeds 30% by mass, the preferred adhesiveness may not be obtained as an optical use.

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains an alkyl group having 1 to 20 carbon atoms in addition to the above-mentioned alicyclic structure-containing monomer. The alkyl acrylate is particularly preferably contained as a main component.

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, can exhibit a preferred adhesion by an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms. Sex. Examples of the (meth)acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, and (meth)acrylic acid. Base ester, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylate Octyl ester, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, (methyl) ) Acrylic stearyl group and the like. Among them, from the viewpoint of further improving the adhesion, a (meth) acrylate having an alkyl group having 1 to 8 carbon atoms is preferable, and methyl (meth)acrylate and n-butyl (meth)acrylate are particularly preferable. Further, these may be used alone or in combination of two or more.

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains from 20% by mass to 99.8% by mass of an alkyl group having 1 to 20 carbon atoms of (meth)acrylic acid alkyl group. The ester is particularly preferably contained in an amount of 50% by mass to 90% by mass, and more preferably 60% by mass to 99% by mass.

Further, the (meth) acrylate polymer (A) preferably contains a monomer having a hydroxyl group (containing a hydroxy monomer) as a monomer unit constituting the polymer. When the adhesive composition P contains the bridging agent (D), the reactivity of the hydroxyl group with the reactive functional group of the bridging agent (D), particularly the isocyanate group of the isocyanate-based bridging agent, is high, and due to these reactions, The acrylate polymer (A) is effectively bridged by the bridging agent (D) to form a good bridging structure. Thereby, the obtained adhesive agent is more excellent in durability.

As the hydroxyl group-containing monomer, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (methyl) a hydroxyalkyl (meth) acrylate such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate, among which The reactivity of the bridging agent (B) of the hydroxyl group in the (meth)acrylate polymer (A) and the copolymerizability with other monomers are preferably 2-hydroxyethyl (meth)acrylate. These may be used alone or in combination of two or more.

The (meth) acrylate polymer (A) preferably contains 0.1% by mass to 10% by mass of the hydroxy group-containing monomer as the monomer unit constituting the polymer, and particularly preferably contains 0.2% by mass to 8% by mass, further It is preferably contained in an amount of 0.3% by mass to 5% by mass. When the content of the hydroxyl group-containing monomer is in the above range, the bridging structure formed is good, and the obtained adhesive has more excellent durability. When the content of the hydroxyl group-containing monomer is less than 0.1% by mass, the bridging point is too small, and it is difficult to obtain an effect of improving durability. On the other hand, when the content of the hydroxyl group-containing monomer exceeds 10% by mass, the bridging point is excessive, and the obtained binder is not soft and the stress relaxation property may be lowered.

The (meth) acrylate polymer (A) preferably contains no carboxyl group-containing monomer (containing a carboxyl group monomer) as a monomer unit constituting the polymer. By a monomer which does not substantially contain a carboxyl group having an acid component, it is possible to suppress a defect caused by an acid to be attached to the obtained adhesive, and for example, even in the case of a transparent conductive film or a metal film, it is possible to suppress them. Bad due to acid. In particular, when the attached object is a transparent conductive film, it is possible to suppress the transparent conductive film from being corroded or the resistance value of the transparent conductive film from changing. Further, as with the decane coupling agent (C) to be described later, the polymer which is not affected by the acid also functions effectively. Further, by substantially not containing a monomer having a carboxyl group, the carboxyl group can be prevented from inhibiting the reaction between the hydroxyl group of the hydroxyl group-containing monomer and the bridging agent (D), particularly the isocyanate-based bridging agent.

The (meth) acrylate polymer (A) may contain other monomers as needed in addition to the above monomers. The other monomer may be a monomer having a reactive functional group other than a hydroxyl group (containing a reactive functional group monomer), or may be a non-reactive monomer.

The monomer having a reactive functional group may, for example, be a monomer having an amino group (containing an amino monomer). Examples of the amino group-containing monomer include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These may be used alone or in combination of two or more.

Examples of the non-reactive monomer include methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and (meth)acrylic acid. (meth) acrylate, acrylamide, methacrylamide containing an aromatic ring such as an alkoxyalkyl (meth) acrylate or a (meth) acrylate such as an ethoxyethyl group Non-branching acrylamide, (a (meth) acrylate or vinyl acetate having a non-branching tertiary amino group such as N,N-dimethylaminoethyl acrylate or N,N-dimethylaminopropyl (meth) acrylate , styrene, etc. These may be used alone or in combination of two or more.

The polymerization method of the (meth) acrylate polymer (A) may be a random copolymer or a block copolymer.

The (meth) acrylate polymer (A) has a weight average molecular weight of from 900,000 to 3,000,000, preferably from 1,000,000 to 2,500, and particularly preferably from 1,1,000,000 to 2,000,000. The weight average molecular weight in the present specification is a value in terms of polystyrene measured by a gel permeation chromatography (GPC) method.

When the weight average molecular weight of the (meth) acrylate polymer (A) is less than 900,000, the durability of the obtained adhesive is inferior. Further, when the weight average molecular weight of the (meth) acrylate polymer (A) exceeds 3,000,000, the adhesive strength of the obtained adhesive is lowered.

In the adhesive composition P, the (meth) acrylate polymer (A) may be used singly or in combination of two or more. Further, the adhesive composition P may further contain a (meth) acrylate polymer which does not contain the above-described alicyclic structure-containing monomer as a constituent monomer unit.

(2) Active energy ray curable component (B)

The active energy ray-curable component (B) is not particularly limited as long as it does not impair the effects of the present invention, and is cured by irradiation with an active energy ray. It may be any of a monomer, an oligomer or a polymer. One may also be a mixture thereof. Among them, a polyfunctional acrylate having a molecular weight of less than 1,000 which is excellent in compatibility with a (meth) acrylate polymer (A) or the like is preferably used. (acrylate) monomer.

Examples of the polyfunctional acrylate monomer having a molecular weight of less than 1,000 include 1,4-butanediol di(meth)acrylate and 1,6-hexanediol di(meth)acrylate. Neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyllgic acid adipate di(meth)acrylate, hydroxyl Hydroxyvalivalic acid neopentylglycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone modification Caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide modified di(meth)acrylate, bis(acryloyloxyethyl)isocyanate Bifunctional type such as di(acryloxy ethyl)isocyanurate), allylated cyclohexyl di(meth)acrylate; trimethylolpropane tri(meth)acrylate, Pentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate (propionic aci) D-modified dipentaerythritol tri(meth)acrylate), pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, three a trifunctional type such as (acryloyloxyethyl)isocyanate; a tetrafunctional type such as diglycerin tetra(meth)acrylate or pentaerythritol tetra(meth)acrylate; A 5-functional type such as dipentaerythritol penta (meth) acrylate; a bifunctional type such as dipentaerythritol hexa(meth) acrylate or caprolactone-modified dipentaerythritol hexa(meth) acrylate. These may be used alone or in combination of two or more.

Among the above polyfunctional acrylate monomers, a polyfunctional acrylate monomer having a cyclic structure in a skeleton is preferable because it has more excellent durability. The cyclic structure may be a carbocyclic structure or a heterocyclic structure, and may have a single ring structure or a polycyclic structure. Examples of the polyfunctional acrylate monomer as described above include an isocyanate structure such as di(acryloxyethyl)isocyanurate or tri(acryloxyethyl)isocyanate. Polyfunctional acrylate monomer, dimethylol dicyclopentane diacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclic dimethanol acrylate, adamantane diacrylate, etc. .

As the active energy ray-curable component (B), an active energy ray-curable acrylate-based oligomer can also be used. The acrylate oligomer preferably has a weight average molecular weight of 50,000 or less. Examples of the acrylate-based oligomers include polyester acrylates, epoxy acrylates, urethane acrylates, polyether acrylates, and polybutylenes. Ethylene acrylates, silicone acrylates, and the like.

Here, the polyester acrylate oligomer can be, for example, a hydroxyl group or an ester of a polyester oligomer having a hydroxyl group at both terminals, which is obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth)acrylic acid. Alternatively, it may be obtained by esterifying a hydroxyl group at the terminal of the oligomer obtained by adding an oxymethylene to the polyvalent carboxylic acid with (meth)acrylic acid. The epoxy acrylate oligomer can be, for example, reacted and esterified on an oxirane ring of a bisphenol type epoxy resin or a novolac type epoxy resin having a relatively low molecular weight. And get it. Further, the epoxy acrylate oligomer may be used in a dibasic character carboxylic acid anhydride. The obtained carboxy-modified epoxy acrylate oligomer is modified by division. An urethane acrylate oligomer, for example, a polyurethane obtained by reacting a polyether polyol or a polyester polyol with a polyisocyanate with (meth)acrylic acid The oligomer is obtained by esterification. The polyol acrylate oligomer can be obtained by esterifying a hydroxyl group of a polyether polyol with (meth)acrylic acid.

The weight average molecular weight of the above acrylate-based oligomer is preferably 50,000 or less, particularly preferably 500 to 50,000, and further preferably 3,000 to 40,000. These acrylate oligomers may be used alone or in combination of two or more.

Further, as the active energy ray-curable component (B), an adduct acrylate obtained by introducing a group having a (meth) acryloyl group into a side chain may be used. polymer. Such an adduct acrylate-based polymer can have a (meth) acrylonitrile group and a bridging functional group by using a copolymer of a (meth) acrylate and a monomer having a bridging functional group in the molecule. The compound of the reactive group is obtained by reacting a part of the bridging functional group of the copolymer.

The (meth) acrylate is preferably an alkyl (meth) acrylate having an alkyl group and having 1 to 20 carbon atoms, and examples thereof include methyl (meth)acrylate and ethyl (meth)acrylate. Base ester, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (methyl) ) 2-ethylhexyl acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, myristyl (meth) acrylate, ( Methyl hexadecyl acrylate, (A Base) stearyl acrylate and the like. These may be used alone or in combination of two or more.

The monomer having a bridging functional group in the molecule preferably contains at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, and a guanamine group as a functional group. Examples of the monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and (meth)acrylic acid 2. -Hydroxybutyl (meth)acrylate, such as -hydroxybutyl ester, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate; acrylamide, methacrylamide , propylene amide such as N-methyl acrylamide, N-methyl methacrylamide, N-methylol acrylamide, N-methylol methacrylamide; (meth) acrylate Methylaminoethyl ester, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, monoethylaminopropyl (meth)acrylate, etc. A monoalkylaminoalkyl acrylate; an ethylenically unsaturated carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid or citraconic acid. These monomers may be used singly or in combination of two or more.

As a compound having a group reactive with a (meth)acryloyl group and a bridging functional group, for example, 2-methylpropenyloxyethyl isocyanate or methacrylic acid 2 can be preferably used. -(0-[1'-methylpropanylamino]carboxyamino)ethyl, 2-[(3,5-dimethylpyrazole)carbonylamino]ethyl methacrylate, 1,1-(double Propylene oxime methyl)ethyl isocyanate, 2-propenyl oxiranyl ethyl isocyanate, 2-propenyl oxyethyl succinate, succinate, 2-propenyl oxiranyl hexahydrophthalate Ω-carboxy-polycaprolactone monoacrylate, monohydroxyethyl phthalate, 2-hydroxy-3-phenoxypropyl acrylate or the like. These compounds may be used singly or in combination of two or more.

The weight average molecular weight of the above-mentioned additive acrylate polymer is preferably from about 300,000 to 2,000,000, particularly preferably from about 500,000 to 850,000.

The active energy ray-curable component (B) can be selected from the above-mentioned polyfunctional acrylate monomer, acrylate oligomer, and adduct acrylate polymer. Two or more types may be used in combination, and may be used in combination with active energy ray-curable components other than these.

The content of the active energy ray-curable component (B) in the adhesive composition P is preferably 1 part by mass to 30 parts by mass based on 100 parts by mass of the (meth) acrylate polymer (A), and particularly preferably It is 2 parts by mass to 20 parts by mass, and more preferably 3 parts by mass to 9 parts by mass. The adhesive obtained from the adhesive composition P containing the active energy ray-curable component (B) in this range is presumably formed as a binder of the above-described three-dimensional network structure.

(3) decane coupling agent (C)

The adhesive composition P, as a functional group reactive with an organic material, contains a decane coupling agent (C) having a mercapto group, and reacts with the active energy ray-curable component (B) by a decane coupling agent (C). The reaction of the decane coupling agent (C) with the adherend and the polycondensation reaction of the decane coupling agent (C) exhibit an effect of improving the adhesion. In addition, the effect of the case where the adhesive composition P contains the bridging agent (D) is demonstrated below.

As a decane coupling agent (C), it has at least one ruthenium in the molecule. The organic ruthenium compound having at least one alkoxysilyl group has good compatibility with the binder component and has light permeability. For example, it is preferably substantially transparent.

Specific examples of the above decane coupling agent (C) include 3-mercaptopropyltrimethoxydecane, 3-mercaptopropyltriethoxydecane, and 3-mercaptopropyldimethoxymethylnonane. a thiol-containing low molecular type decane coupling agent; a mercapto group containing 3-mercaptopropyltrimethoxydecane, 3-mercaptopropyltriethoxydecane, 3-mercaptopropyldimethoxymethylnonane, or the like Sulfhydryl group-containing fluorenyl group, such as a copolycondensate of an alkyl group-containing decane compound such as methyl triethoxy decane, ethyl triethoxy decane, methyl trimethoxy decane or ethyl trimethoxy decane Oligomer type decane coupling agent and the like. In particular, from the viewpoint of improving durability, an oligomer-type decane coupling agent containing a mercapto group is preferable, and a mercapto compound containing a mercapto group and a copolycondensate containing an alkyldecane compound are more preferable, and 3-mercaptopropyl group is further more preferable. A copolycondensate of a trimethoxy decane and methyl triethoxy decane. These may be used alone or in combination of two or more.

The decane coupling agent (C) is preferably an oligomer. In the decane coupling agent (C) of the above oligomer, the thiol group equivalent in the oligomer is preferably from 100 g/mol to 1000 g/mol, particularly preferably from 200 g/mol to 900 g/mol, further preferably from 300 g/mol to 700 g. /mol. If the thiol equivalent is less than 100 g/mol, the effect of improving durability may be lowered. When the thiol equivalent exceeds 1000 g/mol, there is a possibility that the adhesion is lowered or the peeling is poor.

The content of the decane coupling agent (C) in the adhesive composition P is preferably 0.01 by mass based on 100 parts by mass of the (meth) acrylate polymer (A). It is preferably 0.02 parts by mass to 3 parts by mass, more preferably 0.05 parts by mass to 2 parts by mass, in parts to 5 parts by mass. When the content of the decane coupling agent (C) is less than 0.01 parts by mass, it is difficult to obtain the effect by the decane coupling agent (C). On the other hand, when the content of the decane coupling agent (C) exceeds 5 parts by mass, the adhesive strength may be extremely lowered or the cohesive force may be insufficient.

(4) bridging agent (D)

The adhesive composition P preferably contains a bridging agent (D). Here, the decane coupling agent (C) contributes to the improvement of durability by the reaction with the active energy ray-curable component (B) or its own polycondensation reaction as described above. Further, if the adhesive composition P contains the bridging agent (D), the sulfhydryl coupling agent (C) thiol group is presumably also reactive with the bridging agent (D) when the adhesive composition P is cured. The functional group reacts. In particular, when the bridging agent (D) is an isocyanate-based bridging agent, the sulfhydryl group of the decane coupling agent (C) and the isocyanate group of the isocyanate-based bridging agent are likely to form a thiourethane bond. On the other hand, the other reactive functional group (isocyanate group of the isocyanate-based bridging agent) of the bridging agent (D) is reacted with the reactive functional group (hydroxyl group, amino group, etc.) of the (meth) acrylate polymer (A). The reaction bridges the (meth) acrylate polymer (A) to form a second three-dimensional network structure. It is presumed that the second three-dimensional network structure is entangled with the three-dimensional network structure formed by the active energy ray-curable component (B) to form an integrated three-dimensional network structure. According to the above configuration, the obtained adhesive becomes an adhesive excellent in durability. Further, the alkoxysilyl group of the decane coupling agent (C) is kept at a suitable distance from the (bridged) (meth) acrylate polymer (A) to be suspended in (meth)acrylic acid. The shape on the ester polymer (A) exerts an excellent coupling effect. The adhesive obtained as described above is excellent in adhesion even under high temperature conditions or Under hot and humid conditions, it is also an excellent adhesion agent.

In the case where the bridging agent (D) is an isocyanate bridging agent, the mercapto group having a decane coupling agent (C) is a (meth) acrylate polymer (A) because it easily reacts with an isocyanate group of an isocyanate bridging agent. The reactive functional group can be obtained only by a hydroxyl group which is difficult to function in a general decane coupling agent (the (meth) acrylate polymer (A) may not contain a carboxyl group as a reactive functional group) The coupling effect from the decane coupling agent (C).

The bridging agent (D) may be a reactive bridging agent which is reactive with a reactive functional group (hydroxyl group, amino group, or the like) of the (meth) acrylate polymer (A), and examples thereof include isocyanates. Bridging agent, epoxy bridging agent, amine bridging agent, melamine bridging agent, aziridine type bridging agent, hydrazine type bridging agent, aldehyde bridging agent, oxazoline bridging agent, metal Alkoxide bridging agent, metal chelate bridging agent, metal salt bridging agent, ammonium salt bridging agent, etc. Among them, the isocyanate-based bridging agent is excellent in reactivity with a mercapto group which the decane coupling agent (C) has, and when the (meth)acrylate polymer (A) has a hydroxyl group, it has reactivity with the hydroxyl group. Excellent strengths. The bridging agent (D) may be used singly or in combination of two or more.

The isocyanate bridging agent is a bridging agent containing at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanate such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and hexamethylene diisocyanate. An alicyclic polyisocyanate such as an aliphatic polyisocyanate, isophorone diisocyanate or hydrogenated diphenylmethane diisocyanate; and a biuret or isocyanurate of these, further Examples of the ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, and the like are added to a reaction product containing a low molecular weight active hydrogen compound. Among them, from the viewpoint of reactivity with a hydroxyl group of the (meth) acrylate polymer (A), a trimethylolpropane-modified aromatic polyisocyanate is preferable, and particularly, a trimethylolpropane-modified xylene-diene is preferable. Isocyanate and trimethylolpropane modified methyl phenyl diisocyanate.

The content of the bridging agent (D) in the adhesive composition P is preferably 0.05 parts by mass to 3 parts by mass, particularly preferably 0.08 parts by mass, per 100 parts by mass of the (meth) acrylate polymer (A). 1.5 parts by mass, more preferably 0.1 parts by mass to 1 part by mass. When the content of the bridging agent (D) is 0.05 parts by mass or more, the effect of improving the durability by the bridging agent (D) can be obtained. When the content of the bridging agent (D) exceeds 3 parts by mass, the degree of bridging is excessive, and the adhesive strength of the obtained adhesive may be lowered.

(5) Photopolymerization initiator (E)

When the ultraviolet ray is used as the active energy ray to be applied to the adhesive composition P, the adhesive composition P preferably further contains a photopolymerization initiator (E). By containing the photopolymerization initiator (E) as described above, the active energy ray-curable component (B) can be effectively cured, and the polymerization curing time and the irradiation amount of the active energy ray can be reduced.

As such a photopolymerization initiator (E), for example, benzene can be cited. Amarantry, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminobenzene Ketone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane 1-ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4-(Methylthio)phenyl]-2-morpholine-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)one, two Benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylindole, 2-ethylhydrazine, 2-tert Butyl hydrazine, 2-amino hydrazine, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-di Ethylthioxanthone, benzyldimethylketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo [2-hydroxy-2-methyl-1[4 -(1-Methylvinyl)benzene]propanone], 2,4,6-trimethylbenzylidene-diphenyl-phosphine oxide, and the like. These may be used alone or in combination of two or more.

The photopolymerization initiator (E) is preferably in an amount ranging from 2 parts by mass to 15 parts by mass, particularly preferably from 5 parts by mass to 12 parts by mass, per 100 parts by mass of the active energy ray-curable component (B). The amount to use.

(6) Various additives

The adhesive composition P may be added with various additives commonly used in acrylic adhesives, such as a charge preventive agent, an adhesion-imparting agent, an oxidation preventive agent, an ultraviolet absorber, a light stabilizer, a softener, and the like, as needed. Filler, refractive index modifier, and the like.

Examples of the antistatic agent include an ionic liquid, an ionic solid, an anionic surfactant, a ruthenium metal salt, a cationic surfactant, and a nonionic surfactant. Among them, an ionic liquid or an ion is preferably used. At least one selected from the group consisting of a solid and a base metal salt.

The ionic liquid and the ionic solid are preferably a nitrogen-containing salt, a sulfur-containing yellow salt, a phosphorus-containing salt or the like. Further, as the base metal salt, it is preferably Lithium salt, potassium salt, etc. These may be used alone or in combination of two or more.

The content of the antistatic agent in the adhesive composition P is preferably 0.5% by mass to 8% by mass, and particularly preferably 1% by mass to 5% by mass. When the content of the antistatic agent is within the above range, the balance between the charging prevention performance and the durability of the adhesive is improved.

[Method for Producing Adhesive Composition]

The adhesive composition P can produce the (meth) acrylate polymer (A), the active energy ray-curable component (B), and the decane coupling agent by producing the (meth) acrylate polymer (A). (C) mixing is carried out, and if necessary, a bridging agent (D), a photopolymerization initiator (E), an additive, or the like is added at any stage to produce.

The (meth) acrylate polymer (A) can be produced by polymerizing a monomer constituting the polymer (in the case of a copolymer, a mixture of monomers) by a usual radical polymerization method. The polymerization of the (meth) acrylate polymer (A) can be carried out by a solution polymerization method or the like using a polymerization initiator as needed. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone, and the like, and two or more kinds thereof may be used in combination.

The polymerization initiator may, for example, be an azo compound or an organic peroxide, and two or more kinds thereof may be used in combination. The azo compound may, for example, be 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile) or 1,1'-azobis(cyclohexane). 1,1-azobis(cyclo-hexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile) (2,2-azobis (2,4) -dimethylvaleronitrile)), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate) ), 4,4'-azobis(4-cyanoshikimate), 2,2'-azobis(2-hydroxyl) Methylpropionitrile, 2,2'-azobis[2-(2-imidazolin-2-yl)propane, and the like.

Examples of the organic peroxide include benzamidine peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, and di-n-propylperoxy. Dicarbonate, bis(2-ethoxyethyl)peroxydicarbonate, tert-butyl peroxy neopentate, tert-butyl peroxypivalate, (3,5,5-trimethyl Benzyl) peroxide, dipropylene peroxide, diethyl hydrazine peroxide, and the like.

Further, in the above polymerization step, the weight average molecular weight of the obtained polymer can be adjusted by mixing a chain shifting agent such as 2-mercaptoethanol.

After obtaining the (meth) acrylate polymer (A), the active energy ray-curable component (B), the decane coupling agent (C), and the base are added to the solution of the (meth) acrylate polymer (A). It is necessary to add a bridging agent (D), a photopolymerization initiator (E), an additive, etc., and mix well, and to obtain the adhesive composition P (coating solution) diluted with a solvent.

As a diluent solvent for diluting the adhesive composition P to obtain a coating solution, an aliphatic hydrocarbon such as hexane, heptane or cyclohexane; an aromatic hydrocarbon such as toluene or xylene; methylene chloride and two may be used. Halogenated hydrocarbon such as ethyl chloride; alcohol such as methanol, ethanol, propanol, butanol or 1-methoxy-2-propanol; acetone, methyl ethyl ketone, 2-pentanone, isophorone a ketone such as cyclohexanone; an ester such as ethyl acetate or butyl acetate; a cellosolve solvent such as ethyl cellosolve;

The concentration and viscosity of the coating solution thus prepared are not particularly limited as long as they are within the range of application, and may be appropriately selected depending on the case. For example, the concentration of the adhesive composition P can be diluted to 10 The amount is %~40% by mass. In addition, when a coating solution is obtained, the addition of a diluent solvent or the like is not a requirement, and the adhesive composition P may be added without any addition as long as it is a coating viscosity. In this case, the adhesive composition P can be directly used as a coating solution.

[adhesive]

The adhesive agent according to the present embodiment can be obtained by applying the adhesive composition P to a desired object, and then curing the adhesive composition P by irradiation with an active energy ray.

The drying of the adhesive composition P can be carried out by air drying, but it is usually carried out by heat treatment (preferably drying with hot air). In the case of heat treatment, the heating temperature is preferably from 50 ° C to 150 ° C, particularly preferably from 70 ° C to 120 ° C. Further, the heating time is preferably from 10 seconds to 10 minutes, particularly preferably from 50 seconds to 2 minutes.

As the active energy ray, ultraviolet rays, electron wires, and the like are usually used. The amount of irradiation of the active energy ray varies depending on the type of the energy ray. However, when it is ultraviolet ray, for example, it is preferably 50 mJ/cm ² to 1000 mJ/cm ² , and particularly preferably 100 mJ/cm ² to 500 mJ/cm. ² . Further, in the case of an electron beam, it is preferably about 10 krad to 1000 krad.

By drying the adhesive composition P and irradiating the active energy ray, a plurality of active energy ray-curable components (B) are combined to form a three-dimensional network structure, and it is presumed that (meth)acrylic acid is formed on the three-dimensional network structure. The structure in which the ester polymer (A) and the decane coupling agent (C) are entangled.

The adhesive obtained by curing the adhesive composition P is passed through the above structure and the alicyclic structure having the (meth) acrylate polymer (A). The optical member such as a polarizing plate, particularly a polycycloolefin, is used for the reaction with the active energy ray-curable component (B) of the decane coupling agent (C) or its own polycondensation reaction. When the member or the transparent conductive film is used as a adherend, the durability is also high, and particularly excellent durability is exhibited even under high temperature conditions or under moist heat conditions.

In addition, when the adhesive composition P contains the bridging agent (D), it is presumed that the (meth) acrylate polymer (A) is bridged by the bridging agent (D) by the above heat treatment, and is also formed. The two-dimensional network structure is intertwined with the three-dimensional network structure formed by the active energy ray-curable component (B) to form an integrated three-dimensional network structure. The thiol group of the decane coupling agent (C) is reacted with a reactive functional group of the bridging agent (D), the alkoxy group of the decane coupling agent (C) is interposed between the bridging agent (D) and the (meth) acrylate The polymer (A) further exists from the above-described three-dimensional network structure at an appropriate distance, and exhibits an excellent coupling effect. The adhesive obtained as described above is excellent in adhesion, and is excellent in durability even under high temperature conditions or under moist heat conditions. For example, it can prevent and suppress the occurrence of floating, peeling, bubbles, and the like under high temperature conditions of 85 ° C or under hot humid conditions of 60 ° C and 90% RH for 500 hours.

The gel fraction of the adhesive according to the present embodiment is preferably 30% to 99%%, particularly preferably 40% to 95%, and more preferably 50% to 90%. When the gel fraction is less than 30%, the cohesive force of the adhesive is insufficient, and durability and reworkability are lowered. On the other hand, if the gel fraction is more than 99%, the adhesive force becomes too low, and the durability may be lowered. In addition, the gel fraction is a value stored in an environment of 23° C. and 50% RH for 7 days (after the ripening period has elapsed) from the time of formation of the adhesive layer. Whether it is mature or not In the case of the period, the gel fraction may be within the above range after being stored in an environment of 23° C. and 50% RH for 7 days.

[bonding sheet]

As shown in Fig. 1, the adhesive sheet 1A according to the first embodiment is laminated on the release sheet 12, the adhesive layer 11 laminated on the release surface of the release sheet 12, and the laminate layer 1A in the order from the bottom to the top. The substrate 13 on the adhesive layer 11 is composed of a substrate 13 .

Further, as shown in Fig. 2, the adhesive sheet 1B according to the second embodiment is formed by the two release sheets 12a and 12b and the peeling surfaces of the two release sheets 12a and 12b. The adhesive layer 11 held by the two release sheets 12a and 12b is formed. In addition, the peeling surface of the peeling sheet in this specification is the surface which has the peeling property in the peeling sheet, and the surface which carried out the peeling process, and the surface which shows the peeling-

In both of the adhesive sheets 1A and 1B, the adhesive layer 11 is composed of an adhesive formed by curing the above-mentioned adhesive composition.

The thickness of the adhesive layer 11 is appropriately determined depending on the purpose of use of the adhesive sheets 1A and 1B, but is usually in the range of 5 μm to 100 μm, preferably 10 μm to 60 μm. For example, when it is used as an optical member, particularly as an adhesive layer for a polarizing plate, it is preferably 10 μm to 50 μm, and particularly preferably 15 μm to 30 μm.

The base material 13 is not particularly limited, and any substrate used as a base material sheet of a usual adhesive sheet can be used. For example, in addition to a desired optical member, a woven fabric or a non-woven fabric using rayon, acryl, or polyester; a synthetic paper; a paper of a top quality paper, a cellophane, an impregnated paper, a copper paper, or the like; Metal foil of aluminum, copper, etc.; urethane foam, polyethylene hair Foam body such as foam; polyester film such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate; polyurethane film, polyethylene film, poly a cellulose film such as a propylene film or triacetyl cellulose; a polyvinyl chloride film, a polyvinylidene chloride film, a polyvinyl alcohol film, an ethylene-vinyl acetate film, a polystyrene film, a polycarbonate film, A plastic film such as an acrylic resin film, a norbornene resin film or a cycloolefin resin film; or a laminate of two or more of these. The plastic film may be a uniaxially rolled film or a biaxially rolled film.

Examples of the optical member include a polarizing plate (polarizing film), a polarizer, a retardation film (retardation film), a viewing angle compensation film, a brightness enhancement film, a contrast film, a liquid crystal polymer film, a diffusion film, and a half. Through a reflective film or the like. In particular, since the polarizing plate is easily shrunk and the dimensional change is large, it is preferably used as a base material for forming the adhesive (the above-mentioned adhesive layer 11) according to the present embodiment from the viewpoint of durability. In particular, a polarizing plate composed of a polycycloolefin thin film (hereinafter referred to as a "COP polarizing plate") is not only easy to shrink, but also has a large change in the inch size, and has a large contact angle and low adhesion. Therefore, from the viewpoint of durability, a substrate which forms the adhesive (the above-described adhesive layer 11) according to the present embodiment is more preferable.

The thickness of the base material 13 varies depending on the type thereof. However, in the case of, for example, an optical member, it is usually 10 μm to 500 μm, preferably 50 μm to 300 μm, and particularly preferably 80 μm to 150 μm.

As the release sheets 12, 12a, 12b, 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, or the like can be used. Polyethylene terephthalate Glycol ester film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene-(meth)acrylic acid copolymer Film, ethylene-(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, and the like. In addition, these bridge films can also be used. Further, these may be laminated films. Further, the release sheets 12, 12a, and 12b preferably have active energy ray permeability.

It is preferable that the peeling surface of the peeling sheet (particularly the surface in contact with the adhesive layer 11) is subjected to a peeling treatment. Examples of the release agent used for the release treatment include a release agent of an alkyd, a silicone, a fluorine, an unsaturated polyester, a polyolefin, and a wax.

The thickness of the release sheets 12, 12a, and 12b is not particularly limited, but is usually about 20 μm to 150 μm.

In the production of the above-mentioned adhesive sheet 1A, the solution (coating solution) containing the adhesive composition P is applied and dried on the release surface of the release sheet 12, and after the coating layer of the adhesive composition P is formed, The substrate 13 is laminated on the coating layer thereof. Then, the adhesive film layer 11 is formed by irradiating the coating film layer with an active energy ray via the peeling sheet 12. In addition, the irradiation conditions regarding the active energy ray are as described above.

Further, in the production of the above-mentioned adhesive sheet 1B, the coating solution containing the above-mentioned adhesive composition is applied and dried on the release surface of one release sheet 12a (or 12b) to form a coating for the adhesive composition P. After the film layer, another release sheet 12b (or 12a) is laminated on the coating layer thereof. Further, the coating film layer is irradiated with the active energy ray via the peeling sheet 12a (or 12b), thereby The adhesive layer 11 is formed.

Further, instead of forming the adhesive layer 11 by irradiating the active energy ray through the release sheet as described above, the coating layer of the adhesive composition P may be formed on the release sheet, and the coating layer may be exposed while being exposed. The active energy ray forms the adhesive layer 11, and thereafter, a substrate or a release sheet is laminated on the adhesive layer 11. Further, a coating layer of the adhesive composition P may be directly formed on the substrate, and the coating layer may be irradiated with an active energy ray to form the adhesive layer 11.

As a method of applying the above coating solution, for example, a bar coating method, a knife coating method, a roll coating method, a plate coating method, a die coating method, a gravure coating method, or the like can be used.

Here, for example, in the liquid crystal display device including the liquid crystal module and the polarizing plate, a polarizing plate is used as the substrate 13 of the bonding sheet 1A, and the peeling sheet 12 of the bonding sheet 1A is peeled off to be exposed. The adhesive layer 11 and the liquid crystal module may be attached.

Further, for example, in a liquid crystal display device in which a retardation plate is disposed between a liquid crystal cell and a polarizing plate, as an example, first, one peeling sheet 12a (or 12b) of the bonding sheet 1B is peeled off, and the bonding sheet 1B is peeled off. The exposed adhesive layer 11 and the phase difference plate are bonded together. Then, the release sheet 12 of the adhesive sheet 1A using the polarizing plate as the base material 13 is peeled off, and the adhesive layer 11 exposed by the adhesive sheet 1A and the phase difference plate are bonded together. Further, the other release sheet 12b (or 12a) is peeled off from the adhesive layer 11 of the adhesive sheet B, and the adhesive layer 11 from which the adhesive sheet B is exposed is bonded to the liquid crystal module.

According to the above adhesive sheets 1A, 1B, the adhesive layer 11 is excellent in durability, and thus can be prevented even under high temperature conditions or under moist heat conditions. It is suppressed that floating, peeling, foaming, or the like occurs between the substrate 13 such as a COP polarizing plate or the adherend.

In addition, the adhesive layer 11 in the adhesive sheets 1A and 1B has a haze value (a value measured according to JIS K7136:2000) of preferably 2.0% or less, particularly preferably 1.8% or less, and further preferably 1.0%. the following. When the haze value is 1.0% or less, the transparency is extremely high, and it becomes an adhesive layer suitable for optical use.

On the other hand, in the adhesive sheets 1A and 1B according to the present embodiment, it is preferable to use a transparent conductive film as an adherend. In this case, the (meth) acrylate polymer (A) in the adhesive composition P preferably does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer. Thereby, it is possible to suppress the adverse effect of the acid component on the transparent conductive film. Specifically, it is possible to suppress the occurrence of corrosion of the transparent conductive film or the change in the resistance value of the transparent conductive film.

Examples of the transparent conductive film include metals such as platinum, gold, silver, and copper; oxides such as tin oxide, indium oxide, cadmium oxide, zinc oxide, and zinc oxide; and indium tin oxide (ITO) of tin. Indium oxide of zinc oxide, indium oxide of fluorine, tin oxide of antimony, tin oxide of fluorine, zinc oxide of aluminum, etc.; non-oxidized compound such as sulfide, antimony hexaboride, titanium nitride, titanium carbide, etc. A transparent conductive film composed of the like.

In addition, as the base material 13, the adhesive sheet 1A of the polarizing plate is used (hereinafter referred to as "adhesive layer polarizing plate"), and the adhesive force is preferably 0.1 N / 25 mm - 25 N with respect to the alkali-free glass. /25 mm, particularly preferably 2N/25 mm to 20 N/25 mm. When the adhesive force is within the above range, it is possible to prevent floating, peeling, or the like from being adhered to the adherend such as a glass plate. In addition, what is said here The adhesive force basically refers to the adhesive force measured by the 180° peeling method based on JIS Z0237:2009, but the measurement sample is cut into a width of 25 mm and a length of 100 mm to make the measurement sample relative to the adherend (alkali-free glass). After attaching at 0.5 MPa and 50 ° C for 20 minutes under pressure, the pressure was measured at a peeling speed of 300 mm/min at a normal pressure of 23 ° C and 50% RH for 24 hours.

Further, the polarizing plate with the adhesive layer is attached to the above-mentioned flawless glass, and the adhesive force after 14 days of placement (adhesion force after 14 days of attachment) is preferably 0.5 N/25 mm to 30 N/25 mm, in particular It is preferably 1 N/25 mm to 25 N/25 mm, and more preferably 2 N/25 mm to 20 N/25 mm. In this way, the increase in the adhesive force generated over time is suppressed, whereby the polarizing plate with the adhesive layer can be evaluated as a polarizing plate excellent in rework. In addition, the adhesive force referred to herein basically refers to the adhesive force measured by the 180° peeling method based on JIS Z0237:2009, but the measurement sample is cut into a width of 25 mm and a length of 100 mm so that the measurement sample is viscous with respect to the adhesion. After being applied at a pressure of 23 ° C and 50% RH for 14 days at a pressure of 30 ° C and 50% RH at a pressure of 0.5 MPa and 50 ° C for 20 minutes, the product (without glass) was measured at a peeling speed of 300 mm/min. Adhesion.

The embodiments described above are described in order to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each of the elements disclosed in the above embodiments includes all design changes and equivalents belonging to the technical scope of the present invention.

For example, the release sheet 12 of the adhesive sheet 1A can be omitted, and either one of the release sheets 12a and 12b in the adhesive sheet 1B can be omitted.

[Examples]

The present invention will be specifically described by the following examples, but the scope of the present invention is not limited by the examples and the like.

[Example 1]

1. Modulation of (meth) acrylate polymer

74 parts by mass of n-butyl acrylate, 5 parts by mass of methyl acrylate, and 20 masses of acrylic acid isobornyl were charged into a reaction vessel including a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube. 1 part by mass of 2-hydroxyethyl acrylate, 200 parts by mass of ethyl phthalate, and 0.08 parts by mass of 2,2'-azobisisobutyronitrile, and the air in the reaction container was replaced with nitrogen. The reaction solution was heated to 60 ° C while stirring in a nitrogen atmosphere, and the reaction was allowed to proceed for 16 hours, followed by cooling to room temperature. Here, the molecular weight of a part of the obtained solution was measured by the method described later, and it was confirmed that the (meth)acrylate polymer (A) having a weight average molecular weight (Mw) of 1.85 million was formed.

2. Modulation of adhesive composition

100 parts by mass of the (meth) acrylate polymer (A) obtained in the above step (1) (converted solid content; the same applies hereinafter); as the active energy ray-curable component (B), tris(acrylic acid) 5 parts by mass of oxyethyl)isocyanate (manufactured by Toagosei Co., Ltd., trade name "ARONIX M-315 " ); as a decane coupling agent (C) having a thiol group as a functional group reactive with an organic material, 3- a copolycondensate of mercaptopropyltrimethoxydecane and methyltriethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X41-1810") 0.3 parts by mass; as a bridging agent (D), trimethylolpropane Modified xylylene diisocyanate (manufactured by Amika Chemical Co., Ltd., trade name "TD-75 " ) 0.4 parts by mass; as photopolymerization initiator (E), benzophenone (Benzophenone) and 1- The hydroxycyclohexyl benzophenone was mixed with 0.5 parts by mass of the obtained polymer (Irgacure 500, manufactured by the company) at a mass ratio of 1:1, mixed, and thoroughly stirred, and diluted with ethyl acetate to obtain an adhesive composition. Coating solution.

Here, the collocation of the adhesive composition is shown in Table 1. The details of the abbreviations and the like described in Table 1 are as follows.

[(Meth)acrylate polymer (A)]

BA: n-butyl acrylate

MA: methyl acrylate

HEA: 2-hydroxyethyl acrylate

IBXA: Isobutyl acrylate

ADMMA: adamantyl methacrylate

DCPA: acrylic acid dicyclopentanyl

CHA: cyclohexyl acrylate

PhEA: 2-phenoxyethyl acrylate

AA: Acrylic

[Hydrane coupling agent (C)]

C1: a copolycondensate of 3-mercaptopropyltrimethoxydecane and methyltriethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X41-1810", thiol equivalent: 450 g/mol)

C2: 3-mercaptopropyltrimethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-803")

C3: 3-glycidoxypropyltrimethoxys ilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403")

[Bridge agent (D)]

XDI: Trimethylolpropane modified xylylene diisocyanate (manufactured by Soken Chemical Co., Ltd., trade name "TD-75")

TDI: Trimethylolpropane modified tolylene diisocyanate (manufactured by Amika Chemical Co., Ltd., trade name "L-45")

3. Manufacture of polarizer with adhesive layer

The coating solution of the obtained adhesive composition was peeled off on one surface of a polyethylene terephthalate film by a silicone-based release agent (Lindeaceae) The peeling-treated surface of the company, SP-PET3811, thickness: 38 μm was applied by a knife coater, and then heat-treated at 90 ° C for 1 minute to form a coating layer of the adhesive composition.

Next, a surface of a polarizer composed of a polyvinyl alcohol film was protected with a triethylene fluorene cellulose film, and a COP polarizing plate having a thickness of 100 μm obtained by protecting the other surface with a cycloolefin polymer film was attached to the above coating. The exposed side of the film layer. Thereafter, the coated film layer was irradiated with ultraviolet rays through the release sheet to form the adhesive layer, thereby obtaining a polarizing plate with an adhesive layer. Further, the thickness of the adhesive layer was 20 μm.

<Ultraviolet irradiation conditions>

. FUSION company's electrodeless lamp uses H bulb

. Illuminance 600mW/cm ² , light quantity 150mJ/cm ²

. UV illumination. The light meter uses "UVPF-36" manufactured by EYE GRAPHICS

[Examples 2 to 22, Comparative Examples 1 to 5]

The type and ratio of each monomer constituting the (meth) acrylate polymer (A), the weight average molecular weight of the (meth) acrylate polymer (A), and the activity The type and/or blending amount of the energy ray-curable component (B), the decane coupling agent (C), the bridging agent (D), and the photopolymerization initiator (E) are changed as shown in Table 1, and In the same manner as in Example 1, a polarizing plate with an adhesive layer was produced. In the seventh embodiment, as the antistatic agent, an adhesive composition further comprising a pyridinium-based ionic liquid (trade name "IL-P18" manufactured by Kyoei Chemical Co., Ltd.) is used.

Here, the above-mentioned weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement).

<Measurement conditions>

. GPC measuring device: manufactured by TOSOH, HLC-8020

. GPC column (the following sequence is passed): TOSOH company

TSK guard column HXL-H

TSK gel GMHXL (×2)

TSK gel G2000HXL

. Determination of flux: tetrahydrofuran

. Measuring temperature: 40 ° C

[Test Example 1] (Measurement of gel fraction)

In the examples or comparative examples, instead of using the polarizing plate used for the polarizing plate with the adhesive layer, one side of the polyethylene terephthalate film was peeled off with a silicone type. A release sheet (SP-PET3801, thickness: 38 μm, manufactured by Linde Co., Ltd.) which was subjected to a release treatment was prepared, and the adhesive sheet was produced. Specifically, the exposed adhesive agent of the constituent body composed of the release sheet/adhesive layer (thickness: 20 μm) obtained by the embodiment or the manufacturing process of the table example The release sheets were laminated on the layer so that the release treatment surface side was in contact with each other. Thus, an adhesive sheet formed of a structure of a release sheet/adhesive layer/release sheet was produced.

The obtained adhesive sheet was aged at 23 ° C and 50% RH for 7 days. Thereafter, the adhesive sheet was made into a sample having a size of 80 mm × 80 mm, and the adhesive layer was wrapped with a polyester mesh (mesh size 200), and only the quality of the adhesive was weighed with a precision balance. The mass at this time is taken as M1.

Next, the above-mentioned polyester net-wrapped adhesive was immersed in ethyl acetate for 24 hours at room temperature (23 ° C). Thereafter, the adhesive was taken out, air-dried for 24 hours in an environment of a temperature of 23 ° C and a relative humidity of 50%, and further dried in an oven at 80 ° C for 12 hours. Only the quality of the dried adhesive was weighed with a precision balance. The mass at this time is taken as M2. The gel fraction (%) is represented by (M2/M1) × 100. The results are shown in Table 2.

[Test Example 2] (Measurement of haze value)

As the measurement sample, the same adhesive sheet as that used for the measurement of the gel fraction (which has been cooked for 7 days) was prepared. The haze value (%) of the adhesive layer (thickness: 20 μm) of the adhesive sheet was measured using a haze meter (NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.) based on JIS K7136:2000. The results are shown in Table 2.

[Test Example 3] (Measurement of adhesion)

A polarizing plate with an adhesive layer obtained in the examples or the comparative examples was cut to prepare a sample having a width of 25 mm and a length of 100 mm. The peeling sheet was peeled off from the sample, and the exposed adhesive layer was placed on the alkali-free glass (Eagle XG, manufactured by Corning Co., Ltd.), and then the pressure cooker manufactured by Kurihara Co., Ltd. was used. 0.5 MPa, 50 ° C, pressurization for 20 minutes. Thereafter, after standing for 24 hours (1 day) or leaving for 14 days under conditions of 23 ° C and 50% RH, a tensile tester (TENSILON, manufactured by Orui Co., Ltd.) was used, and the peeling speed was based on JIS Z0237:2009. The adhesion was measured under conditions of 300 mm/min and a peeling angle of 180° (adhesion force after 1 day of attachment and 14 days after attachment; N/25 mm). The results are shown in Table 2, respectively.

[Test Example 4] (durability evaluation)

The polarizing plate with an adhesive layer obtained in the examples or the comparative examples was cut to prepare a sample having a size of 233 mm × 309 mm. As a sample, a sample which was stored in an environment of 23 ° C and 50% RH for 7 days was prepared from a polarizing plate (forming an adhesive layer) having an adhesive layer. The peeling sheet was peeled off from the sample, and the exposed adhesive layer was attached to an alkali-free glass (manufactured by Corning Co., Ltd., Eagle XG), and then an autoclave made of Kurihara was used at 0.5 MPa and 50 ° C. Press for 20 minutes.

After that, it was placed in an environment of the endurance conditions described below, and after 500 hours, the presence or absence of floating or peeling was confirmed using a magnifying glass of 10 times. The evaluation criteria are as follows. The results are shown in Table 2.

◎: No lifting or peeling was confirmed.

○: It was confirmed that the float or peeling was 0.5 mm or less.

×: Float or peeling of a size of 0.6 mm or more was confirmed.

<endurance condition>

. 85°C dry

. 60 ° C, relative humidity 90% RH

【Table 1】

【Table 2】

As is clear from Table 2, the adhesive of the adhesive layer obtained in the examples had high adhesion and excellent durability.

[Industrial Availability]

The adhesive of the present invention is suitable for optical members, in particular for bonding of polarizing plates, and the adhesive sheet of the present invention is suitable for use as an optical member. In particular, it is suitable as a bonding sheet for a polarizing plate.

1A‧‧‧bonding strip

11‧‧‧Adhesive layer

12‧‧‧ peeling film

13‧‧‧Substrate

Claims (18)

An adhesive composition characterized by having a weight average molecular weight of 900,000 to 3,000,000, comprising: a (meth) acrylate polymer (A) as a monomer unit constituting a polymer, having an alicyclic form a monomer of the structure; an active energy ray-curable component (B); and a decane coupling agent (C) having a thiol group as a functional group reactive with an organic material. The adhesive composition according to claim 1, wherein the adhesive composition further contains a bridging agent (D). The adhesive composition according to claim 1, wherein the (meth) acrylate polymer (A) contains 0.1% by mass to 30% by mass as a monomer unit constituting the polymer. A monomer of the above alicyclic structure. The adhesive composition according to claim 1, wherein the alicyclic structure contains a cyclohexyl skeleton, a dicyclopentadiene skeleton, an adamantane skeleton or an isobornyl skeleton. The adhesive composition according to claim 1, wherein the (meth) acrylate polymer (A) further contains 0.1% by mass to 10% by mass as a monomer unit constituting the polymer. A monomer having a hydroxyl group. The adhesive composition according to claim 1, wherein the (meth) acrylate polymer (A) does not substantially contain a monomer having a carboxyl group as a monomer unit constituting the polymer. The adhesive composition according to claim 1, wherein the active energy ray-curable component (B) is a polyfunctional acrylate monomer having a molecular weight of less than 1,000. The adhesive composition according to claim 7, wherein the polyfunctional acrylate monomer has a cyclic structure. The adhesive composition according to the above aspect of the invention, wherein the content of the active energy ray-curable component (B) in the adhesive composition is relative to the (meth) acrylate polymer (A) 100 parts by mass, from 1 part by mass to 30 parts by mass. The adhesive composition according to the above aspect of the invention, wherein the content of the decane coupling agent (C) in the adhesive composition is relative to the (meth) acrylate polymer (A) 100 parts by mass, 0.01 parts by mass to 5 parts by mass. The adhesive composition according to claim 2, wherein the bridging agent (D) is an isocyanate bridging agent. The adhesive composition according to claim 1, wherein the adhesive composition further contains a photopolymerization initiator (E). An adhesive which is an adhesive which cures the adhesive composition according to any one of claims 1 to 12 by irradiation of an active energy ray. An adhesive sheet characterized in that it is an adhesive sheet having a substrate and an adhesive layer, and the adhesive layer is composed of the adhesive described in claim 13 of the patent application. The adhesive sheet according to claim 14, wherein the substrate is an optical member. The adhesive sheet according to claim 15, wherein the optical member is a polarizing plate. The adhesive sheet according to claim 15, wherein the optical member has a polycycloolefin film. An adhesive sheet comprising: two release sheets; and an adhesive sheet of an adhesive layer held by the release sheet in contact with the release surfaces of the two sheets, wherein the adhesive layer is The composition of the adhesive described in claim 13 of the patent application.