KR20190111973A - Active energy ray curable adhesive composition, adhesive composition for polarizing plates, adhesive for polarizing plates, and polarizing plate using the same - Google Patents

Abstract

It is an active energy ray-curable adhesive composition that is excellent in adhesive strength and is very suitable for bonding to various protective films for polarizing plates and polarizers, and is also excellent in durability such as curability and thermal shock resistance, and includes oxetane compounds (A) and epoxy compounds (B ), An ethylenically unsaturated compound (C) and an active energy ray-curable adhesive composition containing a photopolymerization initiator (D), wherein the epoxy compound (B) contains an aliphatic epoxy compound (B1), and the epoxy compound (B) Provided is an active energy ray curable adhesive composition having a content ratio of 40 to 80% by weight based on the total amount of the oxetane compound (A), the epoxy compound (B) and the ethylenically unsaturated compound (C).

Description

Active energy ray curable adhesive composition, adhesive composition for polarizing plates, adhesive for polarizing plates, and polarizing plate using the same

The present invention relates to an active energy ray-curable adhesive composition, an adhesive composition for a polarizing plate, an adhesive for a polarizing plate, and a polarizing plate using the same, and more particularly, an activity suitable for bonding the polarizer and the protective film constituting the polarizing plate used in a liquid crystal display device or the like. An energy ray curable adhesive composition.

The liquid crystal display device is widely used as an image display device such as a liquid crystal television, a computer display, a mobile phone or a digital camera. Such a liquid crystal display device has the structure which the polarizing plate was laminated | stacked on both sides of the glass substrate in which liquid crystal was enclosed, and various optical function films, such as a phase difference plate, are laminated | stacked on this as needed.

Conventionally, the polarizing plate has the structure which bonded together the protective film on at least one surface, preferably both surfaces of the polarizer which consists of a polyvinyl alcohol-type film (Hereinafter, polyvinyl alcohol abbreviates as "PVA"). Here, as a polarizer, uniaxially-stretched PVA in which dichroic materials, such as iodine, is disperse | distributed and adsorb | sucked in the PVA system film formed using PVA system resin of high saponification degree, and is crosslinked by crosslinking agents, such as boric acid, again Type films are widely used. Since such a polarizer is a uniaxially stretched PVA-based film, it is easy to shrink under high humidity, and a protective film is bonded to the polarizer for the purpose of replenishing moisture resistance and strength.

As such a protective film, thermoplastic resins, such as a cellulose resin, a polycarbonate resin, a cyclic polyolefin resin, a (meth) acrylic resin, and a polyester resin, are excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. Although used, in particular, the protective film which consists of a triacetyl cellulose (TAC) resin has been used widely.

And although these protective films are bonded together with a polarizer by an adhesive agent, PVA type | system | group mainly consisting of PVA-type resin aqueous solution, especially high-VA degree PVA-type resin like a polarizer from a viewpoint of adhesiveness with respect to the polarizer which has a hydrophilic surface as such an adhesive agent Aqueous resin solution is used preferably.

By the way, the thin film of a polarizing plate is calculated | required in recent years, and the acryl-type film and cyclic olefin resin (COP) film came to be used instead of the TAC film which was used most commonly as a protective film until now. However, the protective film replacing these TAC films had the problem that it was difficult to bond firmly with a polarizer with the conventional PVA-type adhesive agent, or the appearance defect of the obtained polarizing plate might arise. This is because acrylic film and COP film are hydrophobic compared with TAC film, and since water vapor transmission rate is low, water cannot be dried sufficiently. For this reason, the development of the various adhesive agent which is suitable also for bonding of protective films, such as an acryl-type film and a COP film, as a substitute for a PVA-type adhesive agent is performed.

For example, Patent Literature 1 discloses an aromatic glycidyl ether, an oxetane compound having a molecular weight of 100 to 800 and a specific amount of an alicyclic type as an adhesive for a polarizing plate having excellent adhesiveness and water resistance, and a specific amount of two or more oxetal groups. A cationically polymerizable adhesive containing a silane coupling agent having an epoxy group and a cationic polymerization initiator has been proposed.

Moreover, in patent document 2, the specific oxetane compound which has two or more oxetanyl groups, an aromatic glycidyl ether, and cationic polymerization as an adhesive agent which can maintain the outstanding state adhesive strength for a long time irrespective of the influence of heat, light, etc. Cationically polymerizable adhesives containing an initiator have been proposed.

In addition, Patent Document 3 proposes a photocurable adhesive composition containing a specific poly (meth) acrylate, a specific polyglycidyl ether, an oxetane compound, a photocationic polymerization initiator, and the like for the purpose of curing and durability as an adhesive. It is.

Patent document 1 WO2012 / 144261A Patent Document 2 JP 2010-229392A Patent Document 3 JP 2015-40283A

However, in Patent Documents 1 and 2, many epoxy groups having a ring structure, such as alicyclic epoxy groups and aromatic epoxy groups, are used, and the adhesive itself tends to be too hard, which is sufficient depending on the type of protective film to be bonded. Adhesive force and durability may not be obtained, and new improvement has been required.

Moreover, in the said patent document 3, when diversification of use environment and high durability are requested | required in recent years, sufficient adhesive force and durability become a problem, and there exists still room for improvement.

Accordingly, in the present invention, an adhesive having excellent adhesion under such a background is particularly suitable for bonding various protective films for polarizing plates and polarizers, and also has excellent adhesive properties such as curing properties, water resistance, heat shock resistance, and the like. It is to provide an active energy ray curable adhesive composition, and an adhesive composition for polarizing plates, an adhesive for polarizing plates, and a polarizing plate using the same.

That is, the present inventors conducted earnest research in view of such a situation, and, as a result, in an active energy ray hardening type adhesive composition which uses a cationic polymerization and a radical polymerization together, an oxetane compound (A), an epoxy compound (B), and ethylene By containing a unsaturated unsaturated compound (C) and a photoinitiator (D), containing an aliphatic epoxy compound (B1) as an epoxy compound (B), and containing more epoxy compounds (B) than ever before, It has been found that an adhesive capable of forming an adhesive layer having excellent balance of durability, curability, and adhesiveness can be obtained.

That is, this invention is an active-energy-ray-curable adhesive composition containing an oxetane compound (A), an epoxy compound (B), an ethylenically unsaturated compound (C), and a photoinitiator (D), The said epoxy compound (B) is An aliphatic epoxy compound (B1) is contained, and the content rate of the said epoxy compound (B) is 40-80 weight with respect to the total amount of the said oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C). An active energy ray curable adhesive composition which is% is made into a 1st summary.

Moreover, this invention makes 2nd summary the adhesive composition for polarizing plates which consists of the active-energy-ray-curable adhesive composition of said 1st summary. Moreover, the adhesive agent for polarizing plates which is hardened | cured material of the adhesive composition for polarizing plates of said 2nd summary is made 3rd summary. And the polarizing plate with which a polarizer and a protective film are bonded by the adhesive agent for polarizing plates of the said 3rd summary makes 4th summary.

This invention contains a lot of epoxy compounds (B) in the case of using photocationic polymerization and photoradical polymerization together. In general, when optical radical polymerization is used in combination for the purpose of increasing the curing speed and improving productivity, when the epoxy compound is contained in a large amount, a sufficient curing rate cannot be obtained, resulting in insufficient curing of the epoxy compound, resulting in durability problems. Although it is considered that it does not increase the content rate of an epoxy compound, in this invention, such a problem does not arise but the adhesive composition which can obtain the adhesive excellent in curability, adhesiveness, and durability is found.

The active energy ray curable adhesive composition of this invention contains an oxetane compound (A), an epoxy compound (B), an ethylenically unsaturated compound (C), and a photoinitiator (D), and the said epoxy compound (B) is an aliphatic type Epoxy compound (B1) is contained, and the content rate of the said epoxy compound (B) is 40 to 80 weight% with respect to the total amount of the said oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C). . For this reason, the effect which is excellent in adhesive force is exhibited, In particular, various polarizing plate protective films and polarizers can fully be adhere | attached, and also the polarizing plate excellent also in durability, such as heat shock resistance, can be obtained.

Moreover, especially in this invention, when the said epoxy compound (B) contains an aromatic epoxy compound (B2) again, it becomes the thing excellent in the balance with durability, such as adhesiveness and heat shock resistance more.

Moreover, especially in this invention, when the content ratio (B1 / B2) of the said aliphatic epoxy compound (B1) with respect to the aromatic epoxy compound (B2) is 10/90-90/10 by weight ratio, it is more adhesiveness and heat shock resistance It is excellent in the balance with durability, such as.

And especially in this invention, the content rate (AB / C) with respect to the said ethylenically unsaturated compound (C) of the total amount (AB) of the said oxetane compound (A) and an epoxy compound (B) is 40/60-a weight ratio. When it is 95/5, it becomes the thing excellent in the balance with durability, such as adhesiveness and heat shock resistance more.

Moreover, especially in this invention, if the content ratio (A / B) of the said oxetane compound (A) with respect to the epoxy compound (B) is 10/90-60/40 by weight ratio, it will be more adhesiveness, heat shock resistance, etc. It is excellent in durability.

And especially in this invention, when the said photoinitiator (D) contains a photocationic polymerization initiator (D1) and an optical radical polymerization initiator (D2), it becomes the thing excellent in the hardenability of an adhesive composition.

Moreover, especially in this invention, when the content rate (D1 / D2) of the said photocationic polymerization initiator (D1) and an optical radical polymerization initiator (D2) is 20/80-99/1 by weight ratio, it is excellent in sclerosis | hardenability of an adhesive composition. It becomes.

Moreover, when the adhesive composition of this invention contains a silane coupling agent (E) again, it becomes the thing excellent in adhesiveness further.

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated in detail, these show an example of preferable embodiment.

The active energy ray-curable adhesive composition (hereinafter, sometimes referred to as "adhesive composition") of the present invention is an oxetane compound (A), an epoxy compound (B), an ethylenically unsaturated compound (C), and a photopolymerization initiator (D). It is made to contain. Hereinafter, each component of an adhesive composition is demonstrated in order.

In addition, in this invention, (meth) acryl means acryl or methacryl to (meth) acryl, acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate, respectively.

<Oxetane compound (A)>

The oxetane compound (A) used in the present invention may be a compound having one or more oxetanyl groups in the molecule.

As said oxetane compound (A), for example, 3-ethyl-3-hydroxymethyl oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- (phenoxy Methyl) oxetane, 3-ethyl-3- (cyclohexyloxymethyl) oxetane, 3-ethyl-3- (oxyranylmethoxy) oxetane, (meth) acrylic acid (3-ethyloxetan-3-yl An oxetane compound having one oxetanyl group in a molecule such as methyl), 3-ethyl-3 '[(3-ethyloxetan-3-yl) methoxy] methyl｝ oxetane, 1,4-bis [( Two oxetanyl groups in a molecule such as 3-ethyl-3-oxetanyl) methoxymethyl] benzene and 4,4'-bis [(3-ethyl-3-oxetanyl) methoxy methyl] biphenyl The oxetane compound etc. which have the above are mentioned. These oxetane compounds (A) can be used individually or in combination of 2 or more types.

Among them, 3-ethyl-3-hydroxymethyloxetane and 1,4-bis [(3-ethyl-3-oxane) are readily available and are excellent in dilution (low viscosity) and compatibility. Cetanyl) methoxymethyl] benzene, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- (oxyranylmethoxy) oxetane, (meth) acrylic acid (3-ethyl jade Cetane-3-yl) methyl, 3-ethyl-3 '[(3-ethyloxetane 3-yl) methoxy] methyl｝ oxetane and the like are preferably used.

Moreover, molecular weight 500 or less is preferable from a viewpoint of coatability and adhesiveness, and especially 100-500 are preferable. A liquid phase is preferable at room temperature (25 ° C), and an oxetane compound containing two or more oxetanyl groups in a molecule or one oxetanyl group and one (meth) in a molecule from the viewpoint of being excellent in curability and durability. The oxetane compound containing an acryloyl group or one epoxy group is preferable, and 3-ethyl-3 '[(3-ethyloxetan-3-yl) methoxy] methyl oxetane and 3-ethyl-3 are especially preferable. -(Oxyranylmethoxy) oxetane and (meth) acrylic acid (3-ethyloxetan-3-yl) methyl are preferably used.

In addition, when an oxetane compound contains an epoxy group or a (meth) acryloyl group in a molecule | numerator, it shall be contained in an oxetane compound (A), and will be mentioned to the epoxy compound (B) or ethylenically unsaturated compound (C) mentioned later do not include.

Specifically as said oxetane compound (A), it is a commercially available "Aronoxetane OXT-101", "Aronoxetane OXT-121", "Aronoxetane OXT-211", "Aronoxetane OXT-212" "Aron oxetane OXT-213", "Aron oxetane OXT-221" (all are the Toagosei company make), etc. can be used. In particular, "aron oxetane OXT-101" and "aron oxetane OXT-221" are preferable.

<Epoxy compound (B)>

This invention uses an epoxy compound (B) as a cation polymerization component. Moreover, it is preferable that the said epoxy compound (B) contains an aliphatic epoxy compound (B1) from an adhesive viewpoint, and also uses an aromatic epoxy compound (B2) together from a viewpoint of the balance of adhesiveness and durability.

As said aliphatic epoxy compound (B1), for example, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, glycidol, C11-C15 alcohol glycidyl ether, Aliphatic epoxy compounds having one epoxy group in a molecule such as lauryl alcohol glycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglyci Dyl ether, trimethylol propane polyglycidyl ether, pentaerythritol polyglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol di Glycidyl ether, polytetramethylene glycol diglycidyl ether, polybutadiene diglycidyl ether, sorbitol polyglycidyl ether, glycerin polyglycidyl ether, polyglycerol polyglycidyl And bifunctional or higher aliphatic epoxy compounds having two or more epoxy groups in a molecule such as a diether. These aliphatic epoxy compounds (B1) can be used individually or in combination of 2 or more types.

Especially, the bifunctional or more aliphatic epoxy compound which has 2 or more epoxy groups in a molecule | numerator from a viewpoint of curability, adhesiveness, and durability is preferable, and 1, 4- butanediol diglycidyl ether and 1, 6- hexanediol di It is preferable to use glycidyl ether and neopentyl glycol diglycidyl ether.

As said aromatic epoxy compound (B2), for example, phenyl glycidyl ether, p-tert- butylphenyl glycidyl ether, p-sec- butylphenyl glycidyl ether, dibromophenyl glycidyl ether Aromatic epoxy compounds having one epoxy group in a molecule such as phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, resorcin diglycidyl ether, hydroquinone diglycidyl ether, bromobisphenol A Diglycidyl ether, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, novolak type epoxy resin, biphenyl type epoxy resin, etc. And aromatic epoxy compounds having two or more epoxy groups in the molecule thereof. These aromatic epoxy compounds (B2) can be used individually or in combination of 2 or more types.

Especially, the aromatic epoxy compound which has 2 or more epoxy groups in a molecule | numerator is preferable from a viewpoint of adhesiveness and durability, and it is preferable to use bisphenol-A epoxy resin and bisphenol-F epoxy resin especially from a viewpoint also excellent in curability.

In the said epoxy compound (B), when using an aliphatic epoxy compound (B1) and an aromatic epoxy compound (B2) together, the content ratio (B1) of an aliphatic epoxy compound (B1) with respect to an aromatic epoxy compound (B2) / B2) is preferably 10/90 to 90/10 by weight, particularly 15/85 to 85/15, 20/80 to 80/20, especially 33/67 to 75/25, and even 50 /. 50-75 / 25, especially 60 / 40-70 / 30.

When the said content ratio is too small (too many aromatic epoxy compounds (B2)), when adhesive force falls or a viscosity raises, coating property will fall or compatibility of an adhesive composition will fall, and when content rate is too large (Too many aliphatic epoxy compounds (B1)) There exists a tendency for durability to fall.

In addition, the epoxy compound (B) used for this invention can contain other epoxy compounds (B3) other than the said aliphatic epoxy compound (B1) and aromatic epoxy compound (B2).

As said other epoxy compound (B3), a triazine skeleton containing epoxy compound, an alicyclic epoxy compound, an alicyclic skeleton containing epoxy compound, etc. are mentioned, for example. These may be used alone or in combination of two or more.

The said triazine skeleton containing epoxy compound contains one or more epoxy groups and a triazine skeleton in a molecule | numerator, For example, tris (2, 3- epoxypropyl)-isocyanurate and tris (3, 4- Epoxybutyl) -isocyanurate, tris (4,5-epoxy pentyl) -isocyanurate, tris (5,6-epoxyhexyl) -isocyanurate, tris (6, 7-epoxyheptyl) -iso Cyanurate, tris (7,8-epoxyoctyl) -isocyanurate, and the like. These may be used alone or in combination of two or more.

It is also preferable to use a triazine skeleton containing epoxy compound from a viewpoint of further improving durability (thermal shock resistance).

The triazine skeleton-containing epoxy compound preferably has an epoxy equivalent of 120 g / eq or more from the viewpoint of adhesion and durability, particularly preferably 130 to 300 g / eq, more preferably 140 to 250 g / eq.

As said triazine frame | skeleton containing epoxy compound, the TEPIC series ("TEPIC-G", "TEPIC-S", "TEPIC-SS", "TEPIC-HP", "made by Nissan Kagaku Kogyo Co., Ltd.) of a commercial item specifically," TEPIC-L "," TEPIC-PAS "," TEPIC-VL "," TEPIC-UC "," TEPIC-FL ", etc. can be used. Especially, "TEPIC-PAS", "TEPIC-VL", "TEPIC-UC", and "TEPIC-FL" which are liquid epoxy compounds are preferable from a compatibility viewpoint.

Examples of the alicyclic epoxy compound include dicyclopentadiene oxide, limonene dioxide, 4-vinylcyclohexene dioxide, 3 ′, 4′-epoxycyclohexylmethyl-3, 4-epoxycyclohexanecarboxylate, ε- Caprolactone-modified 3 ′, 4′-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexyl methyl) adipate and the like. These may be used alone or in combination of two or more.

As said alicyclic epoxy compound, the "Celloxide 2021P", "celloxide 2000", etc. made from all the cell products of a commercial item can be used specifically ,.

As said alicyclic skeleton containing epoxy compound, the epoxy compound in which the aromatic ring like hydrogenated bisphenol A diglycidyl ether is hydrogenated, cyclohexane dimethanol diglycidyl ether, etc. are mentioned, for example. These may be used alone or in combination of two or more.

As said alicyclic skeleton containing epoxy compound, the commercially available "Denacol EX-216L" by Nagase ChemteX Corp. etc. can be used.

It is preferable that at least one content of the said alicyclic epoxy compound and an alicyclic skeleton containing epoxy compound is 30 weight% or less with respect to the total amount of an oxetane compound (A) and an epoxy compound (B), More preferably, it is 20 weight% or less, Especially Preferably it is 15 weight% or less. When at least one content of the said alicyclic epoxy compound and alicyclic skeleton containing epoxy compound is too much, there exists a tendency for adhesive force to fall.

It is preferable that content of the said other epoxy compound (B3) is 30 weight% or less with respect to the whole epoxy compound (B), More preferably, it is 20 weight% or less, Especially preferably, it is 10 weight% or less. When there is too much content of another epoxy compound (B3), there exists a tendency for adhesive force to fall.

<Ethylenic unsaturated compound (C)>

The said ethylenically unsaturated compound (C) becomes a radical polymerization component, and is an unsaturated compound which has at least 1 ethylenically unsaturated group in a molecule | numerator. By containing an ethylenically unsaturated compound (C), hardening rate can be adjusted and hardenability improves.

As said ethylenically unsaturated compound (C), the (meth) acrylic-type compound which has at least 1 (meth) acryloyl group in a molecule | numerator is mentioned, for example.

As said (meth) acrylic-type compound, For example, the (meth) acrylic-type compound which has one (meth) acryloyl group in a molecule | numerator (henceforth a "monofunctional (meth) acrylic-type compound"), 2 in a molecule | numerator The (meth) acrylic-type compound (it may describe as a "polyfunctional (meth) acrylic-type compound" hereafter) which has two or more (meth) acryloyl groups is mentioned.

These (meth) acrylic compounds can be used alone or in combination of two or more.

As said monofunctional (meth) acrylic-type compound, For example, an alkyl (meth) acrylate type compound, a polar group containing (meth) acrylic type compound, an alicyclic (meth) acrylate type compound, an aromatic (meth) acrylate type compound, The (meth) acrylic-type compound etc. which have reactive functional groups other than a (meth) acryloyl group and a (meth) acryloyl group in a molecule | numerator are mentioned.

As an alkyl (meth) acrylate type compound, the alkyl (meth) acrylate which has a C1-C20, especially 1-15, and a 4-10 alkyl group is preferable, specifically, methyl (meth) Acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, etc. are mentioned.

As a polar group containing (meth) acrylic-type compound, For example, a carboxyl group-containing (meth) acrylic-type compound, a hydroxyl group containing (meth) acrylate type compound, a nitrogen atom containing (meth) acrylic-type compound, an alkoxy group containing (meth) acrylate type compound Etc. can be mentioned.

As said carboxyl group-containing (meth) acrylic-type compound, Michael addition of (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide N-glycolic acid, cinnamic acid, (meth) acrylic acid, for example Water (for example, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimmer, methacrylic acid trimmer, acrylic acid tetramer, methacrylic acid tetramer, etc.), 2- (meth) acryloyloxyethyldicarboxylic acid monoester ( For example, 2- (meth) acryloyloxyethyl amber monoester, 2- (meth) acryloyloxyethyl phthalate monoester, 2- (meth) acryloyloxyethyl hexahydrophthalic acid monoester, etc. ), And the like.

As said hydroxyl-containing (meth) acrylate type compound, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6 -Hydroxyalkyl (meth) acrylate-based compounds such as hydroxyhexyl (meth) acrylate, caprolactone-modified (meth) acrylate-based compounds such as caprolactone-modified 2-hydroxyethyl (meth) acrylate, ethylene glycol Mono (meth) acrylate type compounds of dihydric alcohols, such as mono (meth) acrylate, a propylene glycol mono (meth) acrylate, a pentanediol mono (meth) acrylate, and hexanediol mono (meth) acrylate, and di Mono (meth) acrylate of ethylene glycol, mono (meth) acrylate of triethylene glycol, mono (meth) acrylate of tetraethylene glycol, mono (meth) acrylate of polyethylene glycol Mono (meth) acrylate compounds of polyalkylene glycols such as mono (meth) acrylate of dipropylene glycol, mono (meth) acrylate of tripropylene glycol, and mono (meth) acrylate of polypropylene glycol Primary hydroxyl group-containing (meth) acrylate-based compounds such as 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid, and the like; 2-hydroxypropyl (meth) acrylate and 2-hydroxybutyl Secondary hydroxyl group-containing (meth) acrylate-based compounds such as (meth) acrylate; tertiary hydroxyl group-containing (meth) acrylate-based compounds such as 2,2-dimethyl-2-hydroxyethyl (meth) acrylate; Can be mentioned.

Among such hydroxyl group-containing (meth) acrylate-based compounds, primary hydroxyl group-containing (meth) acrylate-based compounds are preferable from the viewpoints of easily causing hydrogen bonding with the base material or polarizer, and excellent in reactivity, and particularly, hydroxyalkyl (meth). An acrylate compound and the mono (meth) acrylate type compound of polyalkylene glycol are preferable.

As said nitrogen atom containing (meth) acrylic-type compound, an amide group containing (meth) acrylic-type compound, an amino group containing (meth) acrylic-type compound, and other nitrogen atom containing (meth) acrylic-type compound are mentioned, for example.

As an amide group containing (meth) acrylic-type compound, For example, (meth) acrylamide; N, N-dialkyl, such as N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide (Meth) acrylamide; N-methoxy methyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide N-alkoxyalkyl (meth) acrylamides such as Nn-butoxymethyl (meth) acrylamide and N-isobutoxymethyl (meth) acrylamide; hydroxyl groups such as N- (hydroxymethyl) (meth) acrylamide Acrylamide; N- (3-N, N-dimethylaminopropyl) (meth) acrylamide, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide and the like. As an amino-group-containing (meth) acrylic-type compound, Primary amino group-containing (meth) acrylates, such as aminoalkyl (meth) acrylate, such as aminomethyl (meth) acrylate and aminoethyl (meth) acrylate, tert, for example Secondary amino group-containing (meth) acrylates, such as butylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc. And heterocyclic amine monomers such as tertiary amino group-containing (meth) acrylates such as dialkylaminoalkyl (meth) acrylates and acryloyl morpholine.

As said alkoxy group containing (meth) acrylate type compound, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, Alkoxyalkyl (meth) acrylate type compounds, such as 2-butoxyethyl (meth) acrylate, 2-butoxydiethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, and methoxy triethylene glycol ( Meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, octosi polyethylene glycol polypropylene glycol mono (meth) acrylate, lau Polyether chain | strand-containing (meth) acrylate type | system | group compound, such as oxy polyethyleneglycol mono (meth) acrylate and stearoxy polyethyleneglycol mono (meth) acrylate And the like.

As an alicyclic (meth) acrylate type compound, cyclohexyl (meth) acrylate, isobonyl (meth) acrylate, 1, 4- cyclohexane dimethylol mono (meth) acrylate, dicyclopentanyl ( Meta) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-adamantyl (meth) acrylate, and the like.

As an aromatic (meth) acrylate type compound, For example, phenyl (meth) acrylate; benzyl (meth) acrylate; phenoxyalkyl, such as phenoxyethyl (meth) acrylate and phenoxypropyl (meth) acrylate (Meth) acrylate; phenoxydialkylene glycol (meth) acrylates such as phenoxydiethylene glycol (meth) acrylate and phenoxydipropylene glycol (meth) acrylate; phenoxy polyethylene glycol (meth) acrylate; phenoxy Polyethylene glycol-polypropylene glycol- (meth) acrylate; (meth) acrylate of p-cumylphenol alkylene oxide adduct, (meth) acrylate of o-phenylphenol alkylene oxide adduct, (phenol) (Meth) acrylate of a meta) acrylate and a nonylphenol alkylene oxide adduct, etc. are mentioned.

As a (meth) acrylic-type compound which has reactive functional groups other than a (meth) acryloyl group and a (meth) acryloyl group in a molecule | numerator, for example, glycidyl methacrylate and 4-hydroxybutyl acrylate glycidyl ether Containing vinyl groups such as epoxy group-containing (meth) acrylate-based compounds such as 3,4-epoxycyclohexylmethyl (meth) acrylate and 2- (2-vinyoxyethoxy) ethyl (meth) acrylate (meth) Isocyanate group containing (meth) acrylate type compounds, such as an acrylate compound and 2- (meth) acryloyloxyethyl isocyanate, etc. are mentioned.

In addition, when an ethylenically unsaturated compound is an epoxy-group-containing (meth) acrylate type compound, it shall be included in an ethylenically unsaturated compound (C) and is not included in an epoxy compound (B).

In addition, the (meth) acrylate type compound which has cyclic ether structures, such as tetrahydro perfuryl (meth) acrylate and a caprolactone modified tetrahydro perfuryl (meth) acrylate, is also mentioned.

Moreover, as a polyfunctional (meth) acrylic-type compound, a bifunctional (meth) acrylic-type compound and the (meth) acrylic-type compound more than trifunctional are mentioned.

As a bifunctional (meth) acrylic-type compound, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acryl Elate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) ) Acrylate, neopentyl glycol di (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, glycerin di (meth) acrylate, pentaeryth Litholdi (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, hydroxy pivaric acid modified neopentyl glycol di ( Di (meth) acrylate which has long chain or branched structure, such as (ta) acrylate; Cyclohexane dimethanol di (meth) acrylate, Dimethylol dicyclopentanedi (meth) acrylate, Tricyclodecane dimethanol di (meth) Di (meth) acrylates having alicyclic structures such as acrylate and ethylene oxide modified cyclohexanedimethanol di (meth) acrylate; ethylene oxide modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type di Alkylene oxide modified bisphenol A type di (meth) acrylates, such as (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and phthalic acid diglycidyl ester di (meth) acrylate, etc. Di (meth) acrylate which has aromatic ring; Di (meth) acrylate which has ring structure, such as isocyanuric acid ethylene oxide modified di (meth) acrylate Yite etc. are mentioned.

As a (meth) acrylic-type compound more than trifunctional, a trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaeryth, for example Ritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyglycerol poly (meth) acrylate; caprolactone modified dipentaerythritol penta (meth) acrylate, caprolactone modified dipenta Rithritol hexa (meth) acrylate, caprolactone modified pentaerythritol tri (meth) acrylate, caprolactone modified pentaerythritol tetra (meth) acrylate, ethylene oxide modified dipentaerythritol penta (meth) acrylic Ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, 3 having a long or branched chain structure, such as a trifunctional or higher (meth) acrylate having an alkyl-modified structure such as ethylene oxide-modified pentaerythritol tetra (meth) acrylate and ethylene oxide-modified glycerin tri (meth) acrylate Functional (meth) acrylate; Tri (meth) acrylate etc. which have ring structure, such as isocyanuric acid ethylene oxide modified triacrylate, are mentioned.

Moreover, oligomers, such as urethane (meth) acrylate, polyester (meth) acrylate, and epoxy (meth) acrylate, can also be used as a (meth) acrylic-type compound.

As said ethylenic unsaturated compound (C), it is preferable to use a bifunctional or more (meth) acrylic-type compound from a viewpoint of improving the hardenability of an adhesive composition and improving durability. In particular, the bifunctional or more (meth) acrylic compound which has an alicyclic ring and an aromatic ring, and the (meth) acrylic compound which has a linear or branched structure which does not have a polyalkylene oxide frame | skeleton are preferable, and also a polyalkylene oxide frame | skeleton Preference is given to (meth) acrylic compounds having a branched structure having no branched structure.

<Photoinitiator (D)>

The adhesive composition of the present invention irradiates an active energy ray, and the oxetane compound (A), the epoxy compound (B), and the ethylenically unsaturated compound (C) react to exhibit adhesiveness. Contains a photoinitiator (D).

It is preferable to contain a photocationic polymerization initiator (D1) as such a photoinitiator (D), and it is especially preferable from a viewpoint of obtaining sufficient sclerosis | hardenability to contain a photocationic polymerization initiator (D1) and a photoradical polymerization initiator (D2). Do.

By using the said photocationic polymerization initiator (D1), hardening at normal temperature (25 degreeC +/- 10 degreeC) of an adhesive composition is attained, and a protective film and a polarizer can be adhere | attached favorably.

The photocationic polymerization initiator (D1) is a compound that generates cationic species and Lewis acids by irradiation with active energy rays. Examples thereof include onium salts such as aromatic diazonium salts, aromatic iodonium salts and aromatic sulfonium salts, and iron- Allen complex, etc. are mentioned.

As said aromatic diazonium salt, benzenediazonium hexafluoro antimonate, benzenediazonium hexafluoro phosphate, benzenediazonium hexafluoro borate etc. are mentioned, for example.

As said aromatic iodonium salt, For example, diphenyl iodonium tetraquis (pentafluorophenyl) borate, diphenyl iodonium hexafluoro phosphate, diphenyl iodonium hexafluoro antimonate, di (4). -Nonylphenyl) iodonium-hexafluoro phosphate etc. are mentioned.

Examples of the aromatic sulfonium salts include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetraquis (pentafluorophenyl) borate, and diphenyl [ 4- (phenylthio) phenyl] sulfonium hexafluorophosphate, 4,4'-bis [diphenylsulfonio] diphenyl sulfide bishexafluorophosphate, 4,4'-bis [di (β) -Hydroxyethoxy) phenylsulfonio] diphenyl sulfide bishexafluoroantimonate, 4,4'-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide Bishexafluorophosphate, 7- [di (p-tolyl) sulfonio] -2-isopropyl thioxanthone hexafluoroantimonate, 7- [di (p-tolyl) sulfonio] -2 Isopropyl thioxanthone tetraquis (pentafluorophenyl) borate, 4-phenylcarbonyl-4'-diphenylsulfonio-diphenyl sulfide hexafluorophosphate, 4- (p- tert-butylphenylcarbonyl) -4'-diphenylsulfonyldiphenylsulfidehexafluoroantimonate, 4- (p-tert-butylphenylcarbonyl) -4'-diphenyl-tolyl) sulfony O-diphenyl sulfide tetraquise (pentafluorophenyl) borate etc. are mentioned.

As said iron-ene complex, xylene cyclopentadienyl iron (II) -hexafluoro antimonate, cumene cyclopentadienyl iron (II) -hexafluoro phosphate, xylene cyclopentadienyl, for example Iron (II) -tris (trifluoromethylsulfonyl) methanide and the like.

Among such photocationic polymerization initiators (D1), it is preferable to use aromatic iodonium salts and aromatic sulfonium salts from the viewpoint of reacting with high sensitivity to a long wavelength light source.

The said photocationic polymerization initiator (D1) can be used individually or in combination of 2 or more types.

Moreover, the radical photopolymerization initiator (D2) generates radicals by irradiation of an active energy ray and reacts an ethylenically unsaturated compound (C). As said radical photopolymerization initiator (D2), for example, diethoxyacetphenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 4- (2-hydroxyethoxy ) Phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl- 1-propane-1-one, 2-methyl-2-morpholino (4-thiomethylphenyl) propane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone Acetphenones such as 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane oligomer; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether Benzoin such as benzoin isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimeth Benzophenones such as -N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethanamium bromide, (4-benzoylbenzyl) trimethylammonium chloride; 2-isopropyl thioxanthone, 4- Isopropyl thioxanthone, 2, 4-diethyl thioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxycyxanthone, 2- (3-dimethylamino-2-hydroxy) Thioxanthones such as -3,4-dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) Acylphosphine oxides such as -2,4,4-trimethyl-pentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; 1,2-octanedione and 1- [4- (Phenyl thio) phenyl-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- ( Oxime esters, such as O-acetyl oxime), etc. are mentioned.

It is preferable to use acylphosphine oxide also in said radical photopolymerization initiator (D2), Especially 2,4,6-trimethylbenzoyl- diphenylphosphine oxide and bis (2,6-dimethoxybenzoyl)- 2,4,4-trimethyl-pentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide are preferable, and 2,4,6-trimethylbenzoyl-phenylphosphine oxide and bis Preference is given to using (2,4,6-trimethylbenzoyl) -diphenylphosphine oxide.

Further, as these preparations, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (mihiraketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethyl benzoic acid and 4-dimethylaminobenzoic acid Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, 4-dimethylaminobenzoic acid isoamyl, 4-dimethylaminobenzoic acid-2-ethylhexyl, 2,4-diethylthioxanthone, 2,4-di It is also possible to use isopropyl thioxanthone together.

In this invention, content of the said photoinitiator (D) is 100 weight part with respect to the total amount of said oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C) from a viewpoint of obtaining sufficient sclerosis | hardenability, It is preferable that it is 0.5-20 weight part, It is especially preferable that it is 0.5-15 weight part, and also 1.0-10 weight part. When such content is too small, there exists a tendency for sclerosis | hardenability to fall, and mechanical strength and adhesive strength may fall, and when too much, there exists a tendency for the solubility to the photoinitiator (D) itself composition to fall.

Moreover, when using the said photocationic polymerization initiator (D1) and an optical radical polymerization initiator (D2) together, the content ratio (D1 / D2) (weight ratio) of a photocationic polymerization initiator (D1) and an optical radical polymerization initiator (D2) is It is preferable that it is 20 / 80-99 / 1, especially 40 / 60-95 / 5, and 50 / 50-90 / 10 from a viewpoint of obtaining sufficient sclerosis | hardenability. If such a content ratio is too small, there exists a tendency for hardening of a cation hardening component not enough to progress, and when too large, there exists a tendency for hardening of a radical hardening component to advancing.

Moreover, it is preferable that content of the said photocationic polymerization initiator (D1) is 0.5-20 weight part with respect to 100 weight part of total amounts of an oxetane compound (A) and an epoxy compound (B), Especially 1-15 weight part, Furthermore, 1.5 -10 weight part is preferable. When there is too much content of a photocationic polymerization initiator (D1), there exists a tendency for solubility to fall or durability to fall, and when too small, sclerosis | hardenability will fall and a mechanical strength and adhesive strength will fall.

It is preferable that content of the said radical photopolymerization initiator (D2) is 15 weight part or less with respect to 100 weight part of ethylenically unsaturated compounds (C), Especially 10 weight part or less, Furthermore, 5 weight part or less is preferable. When there is too much content of a radical photopolymerization initiator (D2), there exists a tendency for the solubility of a radical photopolymerization initiator (D2) to fall, or durability of an adhesive bond layer may fall. In addition, a minimum is 0.1 weight part normally, and when too small, there exists a tendency for sclerosis | hardenability to fall or the adhesive strength and mechanical strength of an adhesive bond layer fall.

Moreover, especially from a viewpoint of hardening efficiency (it can harden | cure efficiently with a small amount of irradiation of an active energy ray), the preferable combination of the said photocationic polymerization initiator (D1) and an optical radical polymerization initiator (D2) is a photocationic polymerization initiator (D1). ) And an aromatic sulfonium salt and an aromatic iodonium salt, and an acyl phosphine oxide as a radical photopolymerization initiator (D2).

The adhesive composition of this invention contains said oxetane compound (A), an epoxy compound (B), an ethylenically unsaturated compound (C), and a photoinitiator (D), and the biggest characteristic of this invention is The content rate of an epoxy compound (B) is 40-80 weight% with respect to the total amount of an oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C), Preferably it is 42-70 weight%, More Preferably it is 45-65 weight%. When there is too little content rate of such an epoxy compound (B), adhesive strength will fall, too much, a hardening rate will fall, a mechanical strength will fall, or durability will fall.

The content ratio (AB / C) of the total amount (AB) of the oxetane compound (A) and the epoxy compound (B) to the ethylenically unsaturated compound (C) is 40/60 to 95/5 by weight ratio. It is preferable from a viewpoint of the balance of durability, It is especially preferable that it is 50/50-90/10, and it is 60/40-85/15. When such a content ratio is too small ((AB) is too small), hardening shrinkage will become large and adhesive force will fall, and when too big (too much (AB)), there exists a tendency for hardening rate to fall.

Moreover, it is preferable that the content rate (A / B) of an oxetane compound (A) with respect to the epoxy compound (B) is 10/90-60/40 by weight ratio from a viewpoint of adhesive force and durability, Especially 12/88- It is preferable that they are 50/50 and 15 / 85-40 / 60. If such a content ratio is too small ((A) is too small), the curing of the epoxy compound (B) does not proceed sufficiently and the durability tends to decrease, and if it is too large (too much (A)), the adhesive force is lowered. Tend to be.

<Silane coupling agent (E)>

In the adhesive composition of this invention, it is preferable to contain a silane coupling agent (E) again from a viewpoint of adhesive improvement.

The said silane coupling agent (E) is an organosilicon compound normally containing 1 or more of a reactive functional group and a silicon atom bond alkoxy group in a structure, and can improve the adhesiveness of an adhesive bond layer and a protective film.

As said silane coupling agent (E), an epoxy group containing silane coupling agent, a mercapto group containing silane coupling agent, a (meth) acryloyl group containing silane coupling agent, an amino group containing silane coupling agent, an isocyanate group containing silane coupling agent, for example And a vinyl group-containing silane coupling agent, a hydroxyl group-containing silane coupling agent, a carboxyl group-containing silane coupling agent and an amide group-containing silane coupling agent. These may be used alone or in combination of two or more.

As said epoxy group containing silane coupling agent, 3-glycidoxy propyl trimethoxysilane, 3-glycidoxy propyl triethoxysilane, 3-glycidoxy propylmethyl diethoxysilane, 3-glycidoxy Epoxy groups of the monomer type, such as glycidyloxy-group (aliphatic epoxy group) containing silane coupling agents, such as propylmethyldimethoxysilane, and alicyclic epoxy group containing silane coupling agents, such as 2- (3, 4- epoxycyclohexyl) ethylpropyl silane; A silane coupling agent or a part of the silane compound is subjected to hydrolysis polycondensation reaction, or an alkyl group-containing silane compound such as methyltriethoxysilane, ethyltriethoxysilane, methylpropylcysilane, ethylpropylcysilane, etc. And co-condensed oligomeric silane coupling agents. These may be used alone or in combination of two or more.

In addition, when a silane coupling agent contains an epoxy group, it shall be included in a silane coupling agent (E), and is not included in an epoxy compound (B).

Examples of the mercapto group-containing silane coupling agent include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, γ-mercaptopropyldimethoxymethylsilane, and 3-mercaptopropylmethyl. A monomer type mercapto group-containing silane coupling agent such as dimethoxysilane, or a part of the silane compound undergoes hydrolysis polycondensation reaction, methyltriethoxysilane, ethyltriethoxysilane, methylpropylcysilane, The oligomer type silane coupling agent etc. which the alkyl group containing silane compounds, such as ethyl propyl silane co-condensed, are mentioned. These may be used alone or in combination of two or more.

As said (meth) acryloyl-group containing silane coupling agent, 3-acryloxypropyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyl diethoxysilane, 3 -Methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, etc. are mentioned. These may be used alone or in combination of two or more.

In addition, when a silane coupling agent contains a (meth) acryloyl group, it is included in a silane coupling agent (E), and is not included in an ethylenically unsaturated compound (C).

Examples of the amino group-containing silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and 3- Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxy cyryl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxy Silane and the like. These may be used alone or in combination of two or more.

As said isocyanate group containing silane coupling agent, 3-isocyanate propyl triethoxysilane etc. are mentioned, for example. These may be used alone or in combination of two or more.

As said vinyl group containing silane coupling agent, vinyl trimethoxysilane, vinyl triethoxysilane, etc. are mentioned, for example. These may be used alone or in combination of two or more.

In addition, when a silane coupling agent contains a vinyl group, it shall be included in a silane coupling agent (E), and is not included in an ethylenically unsaturated compound (C).

Among the silane coupling agents (E), an epoxy group-containing silane coupling agent and a vinyl group are contained in view of excellent reactivity with the cationic polymerization component (oxetane compound (A) and epoxy compound (B)) and the radical polymerization component (C). It is preferable to use a silane coupling agent and a (meth) acryloyl group containing silane coupling agent, Especially preferably, they are an epoxy group containing silane coupling agent and a (meth) acryloyl group containing silane coupling agent. The silane coupling agent (E) may also be an oligomeric silane coupling agent which is partially hydrolyzed and polycondensed even in the monomeric silane coupling agent. However, from the viewpoint of compatibility and adhesiveness, a monomeric silane coupling agent is used. It is preferable.

It is preferable that content of the said silane coupling agent (E) is 2-50 weight part with respect to 100 weight part of total amounts of an oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C), Especially preferably, Is 3-40 weight part, More preferably, it is 5-30 weight part. When there is too much content of a silane coupling agent (E), there exists a tendency for liquid stability to fall or the durability (hardening shock resistance) after hardening falls, and when too small, there exists a tendency which cannot fully acquire the adhesive improvement effect further.

In the adhesive composition of the present invention, in addition to the components described above, a photosensitizer, a polyol, an antistatic agent, other adhesives, an acrylic resin, a urethane resin, a rosin, a rosin ester, a hydrogenated rosin ester, Other additives such as tackifiers such as phenolic resins, aromatic modified terpene resins, aliphatic petroleum resins, cycloaliphatic petroleum resins, styrene resins, xylene resins, plasticizers, colorants, fillers, anti-aging agents, ultraviolet absorbers, and functional pigments; In addition, the compound which causes coloring or discoloration by ultraviolet-ray or radiation irradiation can be mix | blended. Although the compounding quantity of these additives is set suitably for every additive, For example, it is preferable that it is 30 weight% or less of the whole adhesive composition, Especially preferably, it is 20 weight% or less.

In addition to the above additives, a small amount of impurities and the like contained in the raw materials for manufacturing the components of the adhesive composition may be contained.

By using this, the photosensitizer can improve reactivity, and can improve the mechanical strength and adhesive strength of hardened | cured material. Examples of the photosensitizer include anthracene derivatives such as 9,10-dibutoxy anthracene and 9,10-diethoxy anthracene; benzoin methyl ether, benzoin isopropyl ether, α, α-dimethoxy-α-phenyl Benzoin derivatives such as acetphenone; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzo Benzophenone derivatives, such as phenone; Carbonyl compounds, such as anthraquinone derivatives, such as 2-chloro anthraquinone and 2-methyl anthraquinone; 2-chloro thioxanthone, 2-isopropyl thioxanthone, 2, 4- diethyl Organic sulfur compounds such as thioxanthone derivatives such as thioxanthene-9-one; persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducing dyes and the like. These may be used alone or in combination of two or more. Especially, it is preferable to use an anthracene derivative and a thioxanthone derivative.

When using the said photosensitizer as 100 weight part of photoinitiators (D), it is preferable to contain in 0.01-20 weight part. When there is too much content of a photosensitizer, there exists a tendency for a composition and the adhesive bond layer obtained to become colored, and when too small, reactivity falls and there exists a tendency for an effect not to be acquired.

<Adhesive composition>

The adhesive composition of this invention is obtained by mix | blending and mixing in a predetermined ratio using each said component.

In this way, the active energy ray-curable adhesive composition of the present invention is obtained.

The active energy ray curable adhesive composition of this invention becomes an adhesive by hardening | curing by active energy ray irradiation, and can use it especially suitably as an adhesive agent for polarizing plates for bonding a polarizer and a protective film.

<Polarizing plate>

The polarizing plate of this invention bonds a polarizer and a protective film through the adhesive agent for polarizing plates. Specifically, the protective film is bonded together using the adhesive agent for polarizing plates of this invention on at least one surface, Preferably both surfaces of a polarizer, Usually, the adhesive composition for liquid polarizing plates is a polarizer surface or a protective film surface, or both After apply | coating uniformly to a surface, a polarizing plate can be obtained by bonding and crimping | bonding together and performing active energy ray irradiation.

As said polarizer, the film which consists of PVA system resin of 1,500-10,000, saponification degree 85-100 mol%, preferably 95-100 mol% of average degree of polymerization is usually used as an original film, or the aqueous solution or dichroism of potassium iodide iodide A uniaxially stretched film (usually 2 to 10 times, preferably 3 to 7 times stretch ratio) dyed with a dye is used.

The PVA resin is usually produced by saponifying polyvinyl acetate polymerized with vinyl acetate, but a small amount of unsaturated carboxylic acid (including salts, esters, amides, nitriles, etc.), olefins, vinyl ethers, unsaturated sulfonates, and the like. And a component copolymerizable with vinyl acetate. The PVA-based resin also includes so-called polyvinyl acetal resins and PVA derivatives such as polybutyral resin and polyvinyl promal resin, for example, in which PVA is reacted with aldehydes in the presence of an acid.

As a protective film of the said polarizing plate, an acrylic film, a polyethylene film, a polypropylene film, a cycloolefin film, etc. can also be used in addition to the conventional TAC film, The adhesive composition of this invention is a TAC film, an acryl film, cycloolefin. It is used suitably also about any protective film chosen from a system film, a polyethylene terephthalate (PET) type film, etc.

When coating the adhesive composition of the present invention on a polarizer or a protective film, for example, a reverse coater, a gravure coater (direct, reverse or offset), a varistor coater, a roll coater, a die coater, a bar coater, a rod coater, or the like It can be used or coated by dipping.

In the case of the said bonding and crimping | bonding, a roll laminator etc. can be used, for example, and the pressure is normally selected from the range of 0.1-10 Mpa.

As the active energy ray, ultraviolet rays, ultraviolet rays, near ultraviolet rays, rays such as infrared rays, X-rays, γ-rays, and other electromagnetic waves, electron beams, floton rays, neutron rays, and the like can be used. From the ease of use, price, and the like, ultraviolet rays are preferred.

As a light source at the time of the ultraviolet irradiation, a high pressure mercury lamp, an electrodeless lamp, an ultra high pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, an LED lamp and the like are used.

The ultraviolet irradiation is usually carried out under conditions of 2 to 3000 mJ / cm 2, preferably 10 to 2000 mJ / cm 2, and more preferably 20 to 1000 mJ / cm 2.

In particular, in the case of the high-pressure mercury lamp, for example, it is usually carried out under the conditions of 5 to 3000mJ / cm 2, preferably 50 to 2000mJ / cm 2.

In the case of the electrodeless lamp, for example, it is usually carried out under conditions of 2 to 2000 mJ / cm 2, preferably 10 to 1000 mJ / cm 2.

The irradiation time varies depending on the kind of the light source, the distance between the light source and the coated surface, and other conditions after coating, but can usually be for several seconds to several tens of seconds, and for several minutes depending on the case.

On the other hand, in the case of the said electron beam irradiation, it is good to set it as the irradiation amount of 2-50 Mrad using the electron beam which has energy in the range of 50-1000 keV, for example.

Although the irradiation direction of the said active energy ray (ultraviolet ray, an electron beam, etc.) can be irradiated to arbitrary appropriate directions, it is preferable to irradiate from the transparent protective film side from a viewpoint of preventing deterioration of a polarizer.

The thickness of the adhesive bond layer in the polarizing plate of this invention obtained by the above is 0.1-10 micrometers normally, Preferably it is 0.2-5 micrometers, Especially preferably, it is 0.3-3 micrometers, More preferably, it is 0.5-2 micrometers. If the thickness is too thin, the cohesive force of the adhesive force itself cannot be obtained, and the adhesive strength tends not to be obtained. If the thickness is too thick, the workability of the polarizing plate tends to be deteriorated due to cracks during punching.

The active energy ray curable adhesive composition of this invention can be used for various adhesive uses, Especially, it is very suitable for bonding of various protective films for polarizing plates and a polarizer, and shows the outstanding adhesiveness.

(Example)

Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In addition, "part" means a basis of weight in an Example.

Prior to the Example and the comparative example, each component of the adhesive composition shown below was prepared.

[Oxetane Compound (A)]

(A-1) 3-ethyl-3 '[(3-ethyl oxetane 3-yl) methoxy] methyl oxetane (oxetane compound having two oxetanyl groups in the molecule: manufactured by Toagosei Co., Ltd. Cetane OXT-221 '')

[Epoxy Compound (B)]

Aliphatic Epoxy Compound (B1)

(B1-1) Neopentyl glycol diglycidyl ether (Nagase Chemtex Co., Ltd. product "EX-211")

[Aromatic Epoxy Compound (B2)]

(B2-1) Bisphenol F type epoxy resin ("jER806" made by Mitsubishi Chemical Corporation)

[Ethylenically unsaturated compound (C)]

(C-1) neopentyl glycol diacrylate ("light acrylate NP-A" made by Kyoisha Chemical Co., Ltd.)

[Photocationic polymerization initiator (D1)]

(D1-1) Diphenyl [4- (phenylthio) phenyl] sulfonium hexafluoro phosphate (aromatic sulfonium salt: "CPI-100P" by San Apro Company)

[Photo-radical polymerization initiator (D2)]

(D2-1) 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (BASF Co., Ltd. "IrgacureTPO")

[Silane coupling agent (E)]

(E-1) Epoxy group-containing silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-403 (3-glycidoxy propyl trimethoxysilane)") (E-2) Acrylic group-containing silane coupling agent (Shin-Etsu Chemical Co., Ltd. " KBM-5103 (3-acryloxypropyltrimethoxysilane)

[Examples 1-10, Comparative Examples 1-7]

<Preparation of active energy ray curable adhesive composition>

The active energy ray curable adhesive composition was prepared by mix | blending and mixing each said compounding component in the ratio shown in Table 1 of later. The obtained active energy ray curable adhesive composition was used as an adhesive composition for polarizing plates, and it evaluated as follows.

<Production of polarizer>

First, the 60-micrometer-thick PVA film was extended | stretched 1.5 time, immersing in the water tank of 30 degreeC of water temperature. Subsequently, it extended | stretched 1.3 times, immersing for 240 second in the dyeing tank (30 degreeC) which consists of 0.2 g / L of iodine and 15 g / L of potassium iodide. Further, boric acid treatment was performed over 5 minutes while immersing in a boric acid treatment tank (50 ° C.) having a composition of 50 g / L boric acid and 30 g / L potassium iodide, and simultaneously uniaxially stretching 3.08 times. Then, it dried at 90 degreeC and produced the polarizer of 6 times the total draw ratio.

<Production of polarizing plate test piece>

TAC film (Fujifilm company make, brand name "Fujitaek") of size 200mm * 150mm, thickness 60micrometer, and cyclic olefin resin (COP) film (Nippon Xeon company make, brand name "size 200mm * 150mm, thickness 50micrometer" ZEONOR '') was coated on each of the adhesive compositions obtained above with a bar coater so as to have a thickness of 3 μm, thereby obtaining an adhesive composition film. And each adhesive composition layer film was laminated | stacked on both surfaces of the said polarizer of size 180mm * 120mm, respectively, and it bonded together by the nip pressure using 2MPa using a roll machine, and obtained the laminated | multilayer film (Laminated constitution of a laminated film: TAC film / polarizer / COP film) ).

Subsequently, from the COP film side of the laminated film, ultraviolet irradiation is performed at an ultraviolet irradiation device equipped with an electrodeless lamp with a peak illuminance of 400 mW / cm 2 and an integrated exposure amount of 150 mJ / cm 2 (wavelength 365 nm) to cure the adhesive composition to form a polarizing plate. A test piece was produced.

The performance evaluation was performed as follows using the polarizing plate test piece obtained above.

<Performance evaluation>

[Curability]

The interface of a polarizer and a TAC film was peeled off with the cutter knife, and the tackiness of the peeling part was confirmed (touched) with a finger.

(Evaluation standard)

○… There was no leftover.

? No tack left, but some finger marks.

×… Tackiness remained.

(Adhesive force)

The adhesive state of the TAC film, the polarizer, and the COP film and the polarizer when the polarizing plate test piece was cut to 120 mm x 25 mm and subjected to a stress in the 90 ° direction was evaluated according to the criteria as follows.

(Evaluation standard)

◎… In particular, it was firmly bonded.

○… I was firmly bonding.

? Were weakly glued.

×… It did not bond.

(Durability (heat shock resistance))

The test piece was cut into 100 mm x 100 mm, and the thermal shock test which repeated 100 cycles which were left to stand at -40 degreeC for 30 minutes and then left to 85 degreeC for 30 minutes was done. After the test, evaluation was made according to the following criteria.

(Assessment Methods)

○… No appearance defects were observed at all.

? Slight appearance defects (short cracks were generated in the polarizer layer to the extent that the display was not affected) were observed.

×… Poor appearance (through-cracks in the polarizer layer) was confirmed.

From the above results, Examples 1 to 10 containing an oxetane compound (A) and an aliphatic epoxy compound (B1), preferably an aromatic epoxy compound (B2), and also containing an ethylenically unsaturated compound (C) It is understood that the adhesive composition has excellent curability, is excellent in adhesion between the polarizer and the protective film, and also excellent in durability. From this, it turns out that it is suitable for practical use as an adhesive composition for polarizing plates excellent in the balance with various performance.

On the other hand, the comparative example 1 which does not contain an aliphatic epoxy compound (B1) is inferior to adhesiveness, and the comparative example 2 which does not contain an oxetane compound (A) is behind both curability and adhesiveness. The comparative example 3 which is inferior and does not contain an ethylenically unsaturated compound (C) is inferior to sclerosis | hardenability, and not all provided for practical use. Moreover, although the oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C) are contained, in the comparative example 4, the comparative example 5, and the comparative example 6 whose content rate of an epoxy compound (B) is too low, Sufficient adhesion could not be obtained. Moreover, in the comparative example 7 in which the content rate of an epoxy compound (B) is too high, sclerosis | hardenability and durability were inferior. From these things, it can be said that the adhesive composition of a comparative example does not satisfy all the various performances, and cannot provide what is practically used as an adhesive composition for polarizing plates.

As mentioned above, it turns out that the adhesive composition of this invention is especially excellent with respect to the adhesive use for polarizing plates.

Although the said Example was shown about the specific form in this invention, the said Example is only a mere illustration and is not interpreted limitedly. Various modifications apparent to those skilled in the art are intended to be within the scope of the present invention.

The adhesive composition of this invention and the adhesive composition for polarizing plates which consist of said adhesive composition are excellent in the adhesiveness of a polarizer and a protective film, and are suitable for bonding together various protective films for polarizing plates and polarizer. In addition to adhesiveness, it is excellent in balance in all of curability, water resistance of the polarizing plate, durability, and particularly heat shock resistance. Moreover, the adhesive composition of this invention can be used for bonding of various optical films or sheets, bonding of an electronic component, a precision instrument, a packaging material, a display material, etc. besides the said adhesive use for polarizing plates, for example.

Claims (11)

In an active energy ray curable adhesive composition containing an oxetane compound (A), an epoxy compound (B), an ethylenically unsaturated compound (C), and a photoinitiator (D),
The said epoxy compound (B) contains an aliphatic epoxy compound (B1), and the content rate of the said epoxy compound (B) is the thing of the said oxetane compound (A), an epoxy compound (B), and an ethylenically unsaturated compound (C) It is 40 to 80 weight% with respect to the total amount, The active energy ray curable adhesive composition characterized by the above-mentioned. The method according to claim 1,
The said epoxy compound (B) contains an aromatic epoxy compound (B2) further, The active energy ray curable adhesive composition characterized by the above-mentioned. The method according to claim 2,
The content ratio (B1 / B2) of the aliphatic epoxy compound (B1) to the aromatic epoxy compound (B2) is 10/90 to 90/10 by weight ratio, and an active energy ray-curable adhesive composition. The method according to any one of claims 1 to 3,
The content ratio (AB / C) of the total amount (AB) of the oxetane compound (A) and the epoxy compound (B) to the ethylenically unsaturated compound (C) is 40/60 to 95/5 by weight. Active energy ray curable adhesive composition. The method according to any one of claims 1 to 4,
The content ratio (A / B) of the oxetane compound (A) to the epoxy compound (B) is 10/90 to 60/40 by weight ratio, and an active energy ray curable adhesive composition. The method according to any one of claims 1 to 5
Said photoinitiator (D) contains a photocationic polymerization initiator (D1) and a radical photopolymerization initiator (D2), The active-energy-ray-curable adhesive composition characterized by the above-mentioned. The method according to claim 6,
The content ratio (D1 / D2) of the photocationic polymerization initiator (D1) and the radical photopolymerization initiator (D2) is 20/80 to 99/1 by weight ratio, and an active energy ray-curable adhesive composition. The method according to any one of claims 1 to 7,
An active energy ray curable adhesive composition, further comprising a silane coupling agent (E). It consists of the active energy ray curable adhesive composition of any one of Claims 1-8, The adhesive composition for polarizing plates characterized by the above-mentioned. It is a hardened | cured material of the adhesive composition for polarizing plates of Claim 9, The adhesive for polarizing plates characterized by the above-mentioned. The polarizing plate which has an adhesive agent for polarizing plates, a polarizer, and a protective film of Claim 10, The said polarizer and a protective film are bonded together by the said adhesive agent for polarizing plates, The polarizing plate characterized by the above-mentioned.