JP5733175B2 - Active energy ray-curable adhesive composition - Google Patents

Description

The present invention relates to an active energy ray-curable adhesive composition capable of bonding various substrates by irradiation with an active energy ray such as an electron beam or ultraviolet rays.
The composition of the present invention is suitably used for laminating and bonding thin-layer adherends such as plastic films or plastic sheets used as optical components (hereinafter, “films or sheets” are collectively referred to as “films”), Furthermore, it is suitably used for the production of various optical films or sheets used for liquid crystal display elements, EL (electroluminescence) display elements, projection display elements, plasma display elements, etc., and can be used in these technical fields. Is.

Conventionally, in a laminating method in which a thin-layer adherend such as a plastic film or a thin-layer adherend such as a plastic film and a thin-layer adherend made of another material are bonded together, an ethylene-vinyl acetate copolymer is used. A solvent-type adhesive composition containing a polymer or a polyurethane-based polymer is applied to the first thin-layer adherend and dried, and then the second thin-layer adherend is applied to the first thin-layer adherend using a nip roller or the like. The dry laminating method for pressure bonding is mainly performed.
The adhesive composition used in this method generally contains a large amount of a solvent in order to make the coating amount of the composition uniform, but for this reason, a large amount of solvent vapor is volatilized during drying, resulting in toxicity, work safety and Environmental pollution is a problem.
As an adhesive composition for solving these problems, a solventless adhesive composition has been studied.

As the solventless adhesive composition, a two-component adhesive composition and an adhesive composition that is cured by an active energy ray such as an ultraviolet ray or an electron beam are widely used.
As the two-component adhesive composition, a so-called polyurethane adhesive composition is mainly used in which a polymer having a hydroxyl group at the terminal is a main agent and a polyisocyanate compound having an isocyanate group at the terminal is a curing agent. However, the composition has the disadvantage that it takes too long to cure.
On the other hand, the active energy ray-curable adhesive composition is excellent in productivity because of its high curing rate, and has recently attracted attention.

On the other hand, thin display devices such as liquid crystal display devices have been widely used as display elements for televisions, portable personal computers, mobile phones, word processors and the like as well as simple display devices in digital watches and various electric appliances. In recent years, an active energy ray-curable adhesive has been used for bonding various optical films used in the liquid crystal display element.
The adhesive composition used in the optical film is required to have a performance capable of maintaining the adhesive force under severe conditions under high temperature and high humidity conditions. However, most of the conventional active energy ray-curable adhesive compositions are excellent in initial adhesive strength, but if they are used for a long time under high temperature or high humidity conditions, the adhesive strength decreases and causes peeling. Or whitening due to moisture absorption.

The present applicant has, as an active energy ray-curable adhesive composition having excellent adhesion at high temperatures and high humidity, a composition containing a urethane (meth) acrylate and a polymer having a glass transition temperature of 40 ° C. or higher. (Patent document 1) and the composition (patent document 2) containing the urethane (meth) acrylate and the (meth) acrylate which has a cyclic imide group are proposed.
In addition, the applicant of the present application is a composition comprising a urethane (meth) acrylate having a specific structure and a specific monofunctional (meth) acrylate having a cyclic structure as an adhesive, and an activity containing methacrylate at a specific ratio. An energy ray curable adhesive composition (Patent Document 3) is proposed.

JP 2000-072833 A (Claims) JP 2001-064594 A (Claims) International Publication No. WO2006 / 118078 Pamphlet (Claims)

However, when a conventional active energy ray adhesive composition is used for bonding a plastic film, the laminate obtained by curing shrinkage may be warped (curl) in some cases.
In addition, in recent years, heat generated from various driving devices and light sources may be concentrated on a part of the film laminate without being diffused due to thinning and miniaturization of display devices, and sunlight such as car navigation may be exposed to sunlight. When the product is used outdoors, only a part of the product, not the entire product, may become excessively hot. In the case of a film laminate using a conventionally proposed adhesive composition, deflection occurs when heat concentrates on a part of the film laminate, resulting in problems such as reduced visibility and distortion of the resulting image. It has become to.
In addition, the above-described adhesive composition for optical film uses not only the above-described high-temperature and high-humidity conditions but also the ability to be colored or less colored under high-temperature and high-humidity conditions. Is required. However, although the conventional adhesive composition satisfies the above-described performance, coloring under high temperature and high humidity conditions sometimes becomes a problem.
Therefore, the present inventors have excellent adhesive strength, do not cause warp in the obtained laminate, have little deflection of the film laminate even under partially heated conditions, and further under high temperature and high humidity conditions In addition, in order to find an active energy ray-curable adhesive composition with little coloration after the wet heat test, an extensive study was conducted.

As a result of various studies, the present inventors have found that a composition comprising a urethane (meth) acrylate and a (meth) acrylamide compound, which contains a compound having a methacryloyl group at a specific ratio. The agent composition was excellent in adhesive force, and it was found that the film deflection was suppressed even when used under high temperature, and it was at a practical level, and the present invention shown below was completed.
In the present invention, (A) urethane (meth) acrylate having two or more (meth) acryloyl groups [hereinafter referred to as “component (A)”. ],
(B) A (meth) acrylamide compound [hereinafter referred to as “component (B)”] containing (meth) acrylamide represented by the general formula (1) described below [hereinafter referred to as “(meth) acrylamide (1)”]. ],
(C) A compound having two or more ethylenically unsaturated groups, which is a compound other than the component (A) [hereinafter referred to as “component (C)”. And (D) a compound having one ethylenically unsaturated group, which is a compound other than the component (B) [hereinafter referred to as “component (D)”. ]
An active energy ray-curable adhesive composition containing the components (A) to (D) and the compound having a methacryloyl group in the following ratio with respect to the total amount of the components (A) to (D): Related to things.
(A) component: 5-50 weight%
(B) component: 5 to 40% by weight
Component (C): 5 to 40% by weight
Component (D): 2 to 50% by weight
Compound having methacryloyl group: 5 to 30% by weight

  As the component (A), a reaction product of a polyol, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate is preferable, and a non-aromatic urethane (meth) acrylate is preferable. As the component (A), urethane (meth) acrylate having a polyester skeleton or a polycarbonate skeleton is preferable. The component (A) is preferably a compound having a weight average molecular weight of 500 to 50,000.

As the component (B), in the formula (1), the compound R ² and R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms are preferred. Moreover, as (B) component, what contains the compound represented by postscript General formula (2) at 30 weight% or less is preferable.

  (C) As a component, the compound whose glass transition temperature (henceforth "Tg") of a homopolymer is 100 degreeC or more is preferable.

The composition of the present invention preferably further comprises (E) a photopolymerization initiator, and preferably comprises 0.1 to 10 parts by weight of the component (E) with respect to 100 parts by weight of the composition. .
As a composition of this invention, that whose glass transition temperature of hardened | cured material is 60-180 degreeC is preferable. Furthermore, it is preferable that the cured product of the composition has a glass transition temperature of 60 to 180 ° C. and a water absorption of 10% or less.

  In addition, the composition of the present invention can be preferably used for the production of a thin layer laminate, and a laminate composed of a substrate, a cured product of the composition of the present invention and another substrate is preferable. It is preferable that at least one of the substrates is a plastic substrate.

The composition of the present invention can be preferably used as an adhesive composition for a plastic substrate, can be preferably used as an adhesive composition for an optical material, and can be preferably used as an adhesive composition for an optical film laminate.
In the present invention, any one of the compositions described above is applied to a first substrate, and a second substrate is bonded to the first substrate, and then active energy rays are irradiated from the surface of any substrate. It is a manufacturing method of a laminated body.

According to the adhesive composition of the present invention, excellent adhesion to a substrate, particularly excellent adhesion to a plastic substrate, there is no warping of the obtained laminate over time, and deflection after a heating test occurs. In addition, there is little yellowing after the wet heat test.
Therefore, the composition of the present invention is effective for the adhesion of thin-layer adherends such as plastic films used as various optical members by taking advantage of these characteristics, and particularly for the production of optical films used for liquid crystal display devices and the like. It can be suitably used.

Hereinafter, the present invention will be described in detail.
In the present specification, acrylate and / or methacrylate is represented by (meth) acrylate, acryloyl group and / or methacryloyl group is represented by (meth) acryloyl group, and acrylic acid and / or methacrylic acid is represented by (meth) acrylic acid. .

The active energy ray-curable adhesive composition of the present invention contains the components (A) to (D) as essential components.
Hereinafter, each component will be described.
In addition, as (A)-(D) component, each compound mentioned later can be used individually, or can also be used in combination of 2 or more types.

1. Component (A) The component (A) is a urethane (meth) acrylate having two or more (meth) acryloyl groups.
As the component (A), various urethane (meth) acrylates can be used, and specific examples include urethane (meth) acrylates having a polyester skeleton, a polyether skeleton, or a polycarbonate skeleton.
Among these, a urethane (meth) acrylate having a polyester skeleton or a polycarbonate skeleton is preferable in that the cured product obtained has excellent adhesive strength under high temperature and high humidity conditions.
As the component (A), both oligomers and polymers can be used, those having a weight average molecular weight of 500 to 50,000 are preferable, those having a weight average molecular weight of 3,000 to 40,000 are particularly preferable, and 5,000 is particularly preferable. ~ 30,000.
In the present invention, the weight average molecular weight is a value obtained by converting the molecular weight measured by gel permeation chromatography into polystyrene.

More specifically, examples of the component (A) include a reaction product of a polyol, an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate, and the polyol and the organic polyisocyanate reaction product include a hydroxyl group-containing (meth) acrylate. A compound obtained by reacting is preferred.
The component (A) is a urethane (meth) acrylate having two (meth) acryloyl groups [hereinafter also referred to as bifunctional urethane (meth) acrylate. It is preferably a bifunctional urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylate with a reaction product of a diol having a polyester, polyether or polycarbonate skeleton and an organic diisocyanate. .

As the polyol, a diol having a polyester skeleton, a diol having a polyether skeleton, and a diol having a polycarbonate skeleton are preferable.
Examples of the polyol having a polyester skeleton include an esterification reaction product of a diol component such as a low molecular weight diol or polycaprolactone diol and an acid component such as a dibasic acid or an anhydride thereof.
Examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and the like.
Examples of the dibasic acid or an anhydride thereof include adipic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid and terephthalic acid, and anhydrides thereof.
Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, and polyetramethylene glycol.
Examples of the polycarbonate polyol include a reaction product of the low molecular weight diol or / and bisphenol such as bisphenol A and a carbonic acid dialkyl ester such as ethylene carbonate and carbonic acid dibutyl ester.

Organic polyisocyanates include tolylene diisocyanate, 1,6-hexane diisocyanate, 4,4′-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, 1,6-hexane diisocyanate trimer, hydrogenated tolylene diisocyanate, hydrogenated 4 , 4'-diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, paraphenylene diisocyanate, tolylene diisocyanate dimer, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate interadduct, 4,4'-dicyclohexylmethane diisocyanate , Trimethylolpropane tris (tolylene diisocyanate) adduct, isophorone diisocyanate and the like.
The organic polyisocyanate is preferably an organic diisocyanate.

Examples of hydroxyl group-containing (meth) acrylates include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate, and hydroxy Hydroxyalkyl (meth) acrylates such as octyl (meth) acrylate; polyol-containing polyol poly (meth) acrylates such as pentaerythritol tri, di or mono (meth) acrylate, and trimethylolpropane di or mono (meth) acrylate Can be mentioned.
As the hydroxyl group-containing (meth) acrylate, hydroxyalkyl (meth) acrylate is preferable.

(A) As a manufacturing method of a component, what is necessary is just to follow a conventional method,
1) In the presence of a urethanization catalyst, a polyol and an organic polyisocyanate are heated and stirred to carry out an addition reaction to produce a prepolymer having an isocyanate, and then a hydroxyalkyl (meth) acrylate is added thereto, followed by heating and stirring to cause an addition reaction. Examples thereof include a production method and 2) a production method in which a polyol, an organic polyisocyanate, and a hydroxyalkyl (meth) acrylate are heated and stirred in the presence of a urethanization catalyst.
(A) As a component, what was obtained by the manufacturing method of said 1) is preferable.
Examples of the urethanization catalyst include tin-based catalysts such as dibutyltin dilaurate, iron-based catalysts such as tris (acetylacetonato) iron, and zinc-based catalysts such as bis (acetylacetonato) zinc.

As the component (A), a non-aromatic urethane (meth) acrylate is preferable in that the adhesive strength under high humidity is particularly excellent and the cured adhesive is less colored over time.
Specific examples of the non-aromatic urethane (meth) acrylate include urethane (meth) acrylate produced from a non-aromatic polyol and a non-aromatic polyisocyanate.
As the non-aromatic polyol, non-aromatic polyester polyol and polycarbonate polyol are preferable from the viewpoint of less coloring after wet heat.

2. Component (B) The component (B) is a (meth) acrylamide compound containing (meth) acrylamide (1).
In the present invention, by including the component (B), the adhesion to the base material can be improved and the glass transition point of the cured composition can be increased. Can be prevented.
Various compounds can be used as the (meth) acrylamide compound. In the present invention, the compound represented by the following general formula (1), which is (meth) acrylamide (1), is included as an essential component.

[However, in the general formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. R ² and R ³ in one molecule may be the same group or different groups. ]

The hydrocarbon group having 1 to 20 carbon atoms is preferably an alkyl group, which may be linear or branched. The alkyl group may be an alkyl group further having a hydroxyl group, an aromatic group, and a diaminoalkyl group.
Specific examples of the alkyl group include a methyl group, a propyl group, a butyl group, a butyl group, and a hexyl group.
Examples of the alkyl group having a hydroxyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkyl group having an aromatic group include a benzyl group.
Examples of the alkyl group having a hydroxyl group include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
Examples of the dialkylaminoalkyl group include N, N-dimethylaminoethyl group and N, N-dimethylaminopropyl group.
Among these, an alkyl group is preferable, and an alkyl group having 1 to 3 carbon atoms is more preferable.

In the general formula (1), as R ² and R ^3, a compound having a hydrogen atom or an alkyl group having 1 to 3 carbon atoms are preferred.

Specific examples of (meth) acrylamide (1) include N-methyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N -Sec-butyl (meth) acrylamide, Nt-butyl (meth) acrylamide, Nn-hexyl (meth) acrylamide, N-benzyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N, N- Dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-di-n-propyl ( (Meth) acrylamide, N, N-diisopropyl (meth) acrylic Bromide, N, N-di -n- butyl (meth) acrylamide, N, N-dihexyl (meth) acrylamide, N, N-dibenzyl (meth) include (meth) acrylamide derivatives such as acrylamide.
Among these, N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide, which are highly erodible to the substrate, are preferable.

  The component (B) essentially comprises (meth) acrylamide (1), but is further used in combination with a compound represented by the following general formula (2) [hereinafter also referred to as (meth) acrylamide (2)]. Is preferably used in that it does not impair the erodibility to the base material and can reduce heat deflection.

[However, in General formula (2), R < ⁴ > represents a hydrogen atom or a methyl group. ]

  Specific examples of (meth) acrylamide (2) include acryloylmorpholine and methacryloylmorpholine.

When (meth) acrylamide (2) is used as the component (B), the component (B) preferably contains (meth) acrylamide (2) in a proportion of 30% by weight or less, more preferably 5 to 5%. 20% by weight.
When (meth) acrylamide (1) and (2) are used in combination as component (B), (meth) acrylamide (1) is 5 to 35% by weight and (meth) acrylamide (2) is preferably 30 to 5% by weight. More preferably, (meth) acrylamide (1) is 10 to 30% by weight and (meth) acrylamide (2) is 20 to 10% by weight.

3. Component (C) The component (C) is a compound having two or more ethylenically unsaturated groups, and is a compound other than the component (A).
In this invention, since the glass transition point of a composition hardened | cured material can be made high by including (C) component, the bending after the heating test of the laminated body obtained can be prevented.

  Examples of the (C) component ethylenically unsaturated group include a (meth) acryloyl group, a vinyl group, a vinyl ether group, and the like, and a (meth) acryloyl group is preferred.

  As the component (C), compounds having various molecular weights can be used, and any of monomers, oligomers and polymers can be used.

3-1. As monomer monomers, alkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate;
Glycol di (meth) acrylates such as 1,6-hexanediol di (meth) acrylate and neopentyl glycol di (meth) acrylate;
Bisphenol A di (meth) acrylate or halogen nucleus substitution product thereof and bisphenol type di (meth) acrylate such as bisphenol F di (meth) acrylate or halogen nucleus substitution product thereof;
Dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa ( Poly (meth) acrylates such as (meth) acrylates; poly (meth) acrylates of alkylene oxide adducts of the polyols; and di- or tri (meth) acrylates of isocyanuric acid alkylene oxides.
In addition to these, compounds such as those described on pages 53 to 56 of the document "Latest UV Curing Technology" [Printed Information Association, 1991] are listed.

3-2. Examples of the oligomer include polyester (meth) acrylate, epoxy (meth) acrylate, and polyether (meth) acrylate.

3-2-1. Polyester (meth) acrylate oligomer Examples of the polyester (meth) acrylate oligomer include a dehydration condensate of polyester polyol and (meth) acrylic acid.
Here, examples of the polyester polyol include a reaction product of a carboxylic acid with a polyol or an anhydride thereof.
Polyols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, tetramethylene glycol, hexamethylene glycol, neo Low molecular weight polyols such as pentyl glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, glycerin, pentaerythritol and dipentaerythritol, and their alkylene oxide adducts Etc.
As the carboxylic acid or anhydride thereof, dibasic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, adipic acid, succinic acid, fumaric acid, maleic acid, hexahydrophthalic acid, tetrahydrophthalic acid and trimellitic acid, or anhydrides thereof Thing etc. are mentioned.
Examples of the polyester poly (meth) acrylate other than these include compounds described on pages 74 to 76 of the above-mentioned document “UV / EB Curing Material”.

3-2-2. Epoxy (meth) acrylate oligomer Epoxy (meth) acrylate is a compound obtained by addition reaction of (meth) acrylic acid to an epoxy resin, as described in pages 74 to 75 of the above-mentioned document “UV / EB Curing Material”. Compounds.
Examples of the epoxy resin include aromatic epoxy resins and aliphatic epoxy resins.

Specific examples of the aromatic epoxy resin include resorcinol diglycidyl ether; di- or polyglycidyl ether of bisphenol A, bisphenol F, bisphenol S, bisphenol fluorene or an alkylene oxide adduct thereof; phenol novolac type epoxy resin and cresol novolac type Novolak type epoxy resins such as epoxy resins; glycidyl phthalimide; o-phthalic acid diglycidyl ester and the like.
In addition to these, Chapter 2 of the document “Epoxy Resin—Recent Progress—” (published by Shosodo, 1990) and Volume 9 of the literature “Polymer Processing”, Volume 22 Epoxy Resin [Polymer Publishing Society, Compounds published on pages 4 to 6 and pages 9 to 16 of "Showa 48".

Specific examples of the aliphatic epoxy resin include diglycidyl ethers of alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol and 1,6-hexanediol; diglycidyl ethers of polyethylene glycol and polypropylene glycol, etc. Diglycidyl ethers of polyalkylene glycols; diglycidyl ethers of neopentyl glycol, dibromoneopentyl glycol and alkylene oxide adducts thereof; di- or triglycidyl ethers of trimethylolethane, trimethylolpropane, glycerin and alkylene oxide adducts thereof; Of polyhydric alcohols such as di-, tri- or tetraglycidyl ethers of pentaerythritol and its alkylene oxide adducts Ether; hydrogenated bisphenol A and di- or polyglycidyl ethers of alkylene oxide adducts; tetrahydrophthalic acid diglycidyl ether; hydroquinone diglycidyl ether, and the like.
In addition to these, the compounds described on pages 3 to 6 of the above-mentioned document “Polymer Processing”, separate volume epoxy resin, can be mentioned. In addition to these aromatic epoxy resins and aliphatic epoxy resins, epoxy compounds having a triazine nucleus in the skeleton, such as TEPIC [Nissan Chemical Co., Ltd.], Denacol EX-310 [Nagase Kasei Co., Ltd.], etc. may be mentioned. , Compounds described on pages 289 to 296 of the above-mentioned document “Polymer Processing”, separate volume epoxy resin, and the like.
In the above, the alkylene oxide of the alkylene oxide adduct is preferably ethylene oxide or propylene oxide.

3-2-3. Polyether (meth) acrylate oligomers Polyether (meth) acrylate oligomers include polyalkylene glycol (meth) diacrylates, including polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate and polytetramethylene glycol di ( And (meth) acrylate.

3-3. As the polymer polymer, a (meth) acrylic polymer having a (meth) acryloyloxy group, a (meth) acrylic polymer having a functional group, a (meth) acryloyl group introduced into the side chain, Examples thereof include compounds described on pages 78 to 79 of “UV / EB Curing Material”.

3-4. Preferable component (C) As the component (C), among the various compounds described above, a compound having a high homopolymer Tg is preferable. Specifically, a compound having a Tg of 100 ° C. or higher is preferable, and a compound having a Tg of 150 ° C. or higher is more preferable.
Specifically, dimethylol tricyclodecane di (meth) acrylate (Tmethyl of dimethylol tricyclodecane diacrylate = 235 ° C.), trimethylol propane tri (meth) acrylate (Tg of trimethylol propane triacrylate ≧ 250 ° C.) , Diisocyanate or di (tri) acrylate of alkylene oxide isocyanurate [mixture of di and triacrylate (Aronix M-313 manufactured by Toagosei Co., Ltd.) Tg ≧ 250 ° C.], bisphenol A type epoxy acrylate (lipoxy manufactured by Showa Denko KK) SP-1509, Tg = 117 ° C., lipoxy SP-4010, Tg ≧ 250 ° C.).

4). Component (D) Component (D) is a compound having one ethylenically unsaturated group, and is a compound other than the component (B). The component (D) is blended for the purpose of adjusting physical properties such as curability, adhesiveness and resin flexibility.

  (D) As an ethylenically unsaturated group of a component, a (meth) acryloyl group, a vinyl group, a vinyl ether group etc. are mentioned, A (meth) acryloyl group is preferable.

As the component (D), various compounds can be used as long as they are compounds other than the component (B).
Specific examples of the component (D) include ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate and 2-ethylhexyl ( Alkyl (meth) acrylates such as (meth) acrylate;
(Meth) acrylates of phenol alkylene oxide adducts such as benzyl (meth) acrylate, (meth) acrylates of phenol ethylene oxide adducts and (meth) acrylates of phenol propylene oxide adducts, and (meth) acrylates of nonylphenol ethylene oxide adducts And (meth) acrylates such as (meth) acrylates of alkylphenol alkylene oxide adducts such as (meth) acrylates of nonylphenol propylene oxide adducts;
Cycloaliphatic (meth) acrylates such as isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate and dicyclopentanyl (meth) acrylate;
Hydroxyalkyls such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate and hydroxyoctyl (meth) acrylate ( (Meth) acrylate;
2-hydroxy-3-arylpropyl (meth) acrylates such as 2-hydroxy-3-phenoxypropyl (meth) acrylate;
(Meth) acrylic acid and (meth) acrylic acid dimer and trimer (meth) acrylic acid multimers, carboxyl groups such as monohydroxyethyl phthalate (meth) acrylate and ω-carboxy-polycaprolactone mono (meth) acrylate Contains (meth) acrylates.
In addition to (meth) acrylate, N-vinyl compounds such as N-vinyl pyrrolidone and N-vinyl caprolactam can be used.
In addition to these, compounds such as those described on pages 53 to 56 of the document "Latest UV Curing Technology" [Printed Information Association, 1991] are listed.

  The compound of component (D) is preferably selected so that the glass transition temperature of the cured product of the composition described later falls within a preferable range.

5. In the present invention, the proportion of the components (A), (B), (C) and (D) is 5 to 50 weights of the component (A) with respect to the total amount of the components (A) to (D). %, (B) component 5 to 40% by weight, (C) component 5 to 40% by weight and (D) component 2 to 50% by weight, preferably (A) component 15 to 40% by weight, (B) Component 10-35% by weight, (C) component 10-30% by weight, and (D) component 20-40% by weight.
When the proportion of the component (A) is less than 5% by weight, the adhesive strength is lowered, and when it is more than 50% by weight, the deflection due to heat increases. When the component (B) is less than 10% by weight, the adhesive strength is lowered, and when it is more than 40% by weight, coloring with wet heat is increased. When the component (C) is less than 10% by weight, the deflection due to heat increases. On the other hand, when it exceeds 40% by weight, warpage at the time of bonding increases. (D) When there are more components than 50 weight%, adhesive force will fall. (D) By making a component into 2 weight% or more, it can be excellent in adhesive force.

Moreover, the composition of this invention needs to contain 5-30 weight% of compounds which have a methacryloyl group with respect to the total amount of (A)-(D) component. When the amount is less than 5% by weight, warping may occur at the time of bonding, and when the amount is more than 30% by weight, the curability may be delayed and the productivity may be lowered.
What is necessary is just to select the compound which has the said methacryloyl group suitably from above-described (A)-(D) component. As the compound having a methacryloyl group, it is convenient and preferable to select a compound having a methacryloyl group from the component (D).

6). Other Components When the composition of the present invention is cured by ultraviolet rays, a photopolymerization initiator [hereinafter also referred to as component (E)] can be blended as necessary.
Component (E) includes benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenyl Acetophenone, 1,1-dichloroacetophenone, 1-hydroxyacetophenone, 1-hydroxycyclohexyl phenyl ketone and phenylglyoxylic acid methyl ester, oxy-phenylacetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] A mixture of ethyl ester and oxy-phenyl-acetic acid 2- [hydroxy-ethoxy] -ethyl ester, 2-methyl-1- [4- (methylthio) phenyl] -2-methyl Acetophenones such as folinopropan-1-one; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone; 2,4-dimethylthioxanthone, 2, Thioxanthones such as 4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; Monoacylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide Or bisacylphosphine oxide; benzophenones such as benzophenone; and xanthones. These photopolymerization initiators can be used alone or in combination with a benzoic acid-based or amine-based photopolymerization initiation accelerator.
(E) The preferable mixture ratio of a component is 0.1 to 10 weight part with respect to 100 weight part of compositions, More preferably, it is 0.5 to 5 weight part.
Among these, α-hydroxyacetophenone and phosphine oxide are preferred because the cured product is less colored over time.

  The composition of the present invention contains an antioxidant, an ultraviolet absorber, HALS (hindered amine light stabilizer), etc. in an amount of up to 5 parts by weight per 100 parts by weight of the total of components (A) to (D). In addition, a leveling agent for making the coating film thickness uniform and an antifoaming agent for suppressing foaming can be added.

7). Production and Use Method The production method of the composition of the present invention is not particularly limited, and the essential component of the present invention, or the essential component and other components as necessary are stirred or mixed by a commonly used method. Is obtained.
In this case, heating or heating can be performed as necessary.

As a composition of this invention, that whose Tg of hardened | cured material has 60-180 degreeC is preferable, More preferably, it is 80-180 degreeC. If Tg is less than 60 ° C., the adhesive strength during the heat resistance test may decrease, and if Tg exceeds 180 ° C., the initial peel strength may decrease.
In the present invention, Tg means a temperature at which the main peak of the loss tangent (tan δ) of the viscoelastic spectrum of the cured product measured at 1 Hz is maximized.

As the composition of the present invention, a cured product having a Tg of 60 to 180 ° C. and a water absorption of 10% or less is preferable, and more preferably 5% or less.
What has Tg and water absorption of the hardened | cured material in the said range has an effect which can suppress coloring of hardened | cured material.
In the present invention, the water absorption means a value measured according to the following method.
That is, a cured product of the composition is cut into 5 cm × 5 cm and used as a test piece. The test piece is heated at 50 ° C. for 24 hours to completely dry the cured product, and then allowed to cool in a desiccator, and the test piece is weighed (W1). Next, the test piece is immersed in distilled water at 25 ° C. for 24 hours, and after taking out, the water on the surface of the test piece is gently wiped and weighed (W2).
The water absorption means the result calculated according to the following formula (1) based on the obtained results of W1 and W2.
Water absorption (%) = (W2−W1) / W1 × 100 (1)

The composition of the present invention can be used for adhesion of various substrates.
Examples of the substrate include plastic, metal, paper, and the like, and can be suitably used for adhesion of plastic.

As a method for using the composition of the present invention, a conventional method may be used, and examples thereof include a method of irradiating active energy rays after coating on a substrate.
Examples of the active energy rays include visible light, ultraviolet rays, X-rays, and electron beams, but ultraviolet rays are preferable because inexpensive devices can be used.
Various light sources can be used as the light source when cured by ultraviolet rays, and examples thereof include a pressurized or high pressure mercury lamp, a metal halide lamp, a xenon lamp, an electrodeless discharge lamp, a carbon arc lamp, and an LED.
In the case of curing with an electron beam, various devices can be used as an electron beam (EB) irradiation device that can be used, such as a Cockloft-Waltsin type, a bandegraph type, and a resonance transformer type device. As that, what has the energy of 50-1,000 eV is preferable, More preferably, it is 100-300 eV.

The composition of the present invention can be preferably used for the production of a laminate, and may be carried out in accordance with a method usually performed in the production of a laminate. For example, there is a method in which the composition is applied to a first substrate, a second substrate is bonded thereto, and then an active energy ray is irradiated from the surface of any substrate.
The laminate produced in this manner is composed of a substrate, a cured product of the composition of the present invention, and another substrate. In this case, it is preferable that at least one of the substrates is a plastic substrate.

The composition of the present invention can be preferably used as an adhesive composition for optical materials, and can be preferably used as an adhesive composition for optical film lamination.
In this case, a laminate can be produced according to the same method as described above, using a thin layer adherend used as an optical member as the substrate.

Here, the thin-layer adherend used as an optical member is mainly a plastic film and needs to be able to transmit active energy rays. The film thickness depends on the thin-layer adherend to be used and the application. The thickness is preferably 1 mm or less.
Examples of the plastic in the plastic film include polyvinyl chloride resin, polyvinylidene chloride, cellulosic resin, polyethylene, polypropylene, polystyrene, acrylonitrile-butadiene-styrene resin (ABS resin), polyamide, polyester, polycarbonate, polyurethane, polyvinyl alcohol, Examples thereof include ethylene-vinyl acetate copolymer and chlorinated polypropylene. Depending on the intended use, it is also possible to use a material whose surface is subjected to treatment such as metal vapor deposition.
As a coating method for the thin-layer adherend, a conventionally known method may be followed. Natural coater, knife belt coater, floating knife, knife over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, Examples of the method include a reverse roll, an air blade, a curtain flow coater, and a gravure coater.
The coating thickness of the composition of the present invention may be selected according to the thin-layer adherend to be used and the application, but is preferably 0.1 to 1,000 μm, more preferably 1 to 50 μm. is there.

  Since the laminate film or sheet obtained from the adhesive composition of the present invention has excellent adhesive strength under high temperature conditions, a polarizing film, a retardation film, a prism sheet, a brightness enhancement film, a conductive film, and the like used for liquid crystal display devices and the like. It can be suitably used for an optical film or sheet such as a light plate or a diffusion plate.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the following examples, “parts” means parts by weight.

○ Examples 1 to 4 and Comparative Examples 1 to 5
The components (A), (B), (C), (D), and (E) shown in Table 1 and Table 2 below are dissolved by heating and stirring at 60 ° C. for 1 hour to obtain an active energy ray-curable adhesive composition. The thing was manufactured.
The obtained composition was evaluated according to the following test method.

In Tables 1 and 2, each number in the components (A) to (E) means the number of parts, and each abbreviation means the following.
1) UN9200A: Polycarbonate urethane acrylate having a non-aromatic polycarbonate skeleton, weight average molecular weight (hereinafter referred to as “Mw”) of about 15,000 [Negami Kogyo Art Resin UN9200A]
2) OT-1001: Polyester urethane acrylate having a non-aromatic polyester skeleton, Mw of about 40,000 [Aronix OT-1001 manufactured by Toagosei Co., Ltd.]
3) KY-303: polyether-based urethane acrylate, Mw of about 15,000 [KY-303 manufactured by Negami Kogyo Co., Ltd.]
4) DMAA: N, N-dimethylacrylamide [manufactured by Kojin Co., Ltd. DMAA]
5) ACMO: acryloylmorpholine [ACMO manufactured by Kojin Co., Ltd.]
6) M-203S: Tricyclodecane dimethylol diacrylate [Aronix M-203S manufactured by Toagosei Co., Ltd.]
7) M-309: trimethylolpropane triacrylate [Aronix M-309 manufactured by Toagosei Co., Ltd.]
8) M-313: Isocyanuric acid EO-modified di- and triacrylate [Aronix M-313 manufactured by Toagosei Co., Ltd.]
9) IBXA: Isobornyl acrylate [Kyoeisha Chemical Co., Ltd. light acrylate IB-XA]
10) IBX: Isobornyl methacrylate [Kyoeisha Chemical Co., Ltd. light ester IB-X]
11) FA-513M: Dicyclopentanyl methacrylate [FA-513M manufactured by Hitachi Chemical Co., Ltd.]
12) DC MBF: Phenyl glyoxylic acid methyl ester [DAROCUR MBF manufactured by BASF]
13) TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide [DAROCUR TPO manufactured by BASF Corporation]
14) Irg184: 1-hydroxy-cyclohexyl-phenyl-ketone [IRGACURE 184 manufactured by BASF]
15) Proportion of MA: Proportion of compound having a methacryloyl group with respect to the total amount of components (A) to (D) (unit: wt%)
16) M-5700: 2-hydroxy-3-phenoxypropyl acrylate [Aronix M-5700 manufactured by Toagosei Co., Ltd.]

○ Test method
1) Tg
After injecting the obtained composition into a polyethylene terephthalate (PET) film into a rubber mold having a thickness of 1 mm and laminating with a PET film thereon, 120 W / cm, at a position 30 cm from the bottom of a concentrating metal halide lamp, A cured product was obtained by repeatedly passing under the lamp 10 times under the condition of a conveyor speed of 10 m / min.
The obtained cured product was measured with a dynamic viscoelasticity measuring apparatus (EXSTAR DMS6100 manufactured by SII Nanotechnology Co., Ltd.), and the loss tangent (tan δ) of the viscoelastic spectrum of the cured product measured at 1 Hz. Tg was measured from the temperature at which the main peak of the maximum.

2) Water absorption rate The obtained composition was poured into a polyethylene terephthalate (PET) film into a rubber mold having a thickness of 1 mm, laminated on the PET film, and then laminated under the PET film, 120 W / cm from the bottom of a concentrating metal halide lamp. A cured product was obtained by repeatedly passing under the lamp 10 times at a 30 cm position under the condition of a conveyor speed of 10 m / min.
The obtained cured product is cut into 5 cm × 5 cm, and this is used as a test piece. The test piece is heated at 50 ° C. for 24 hours to completely dry the cured product, and then allowed to cool in a desiccator, and the test piece is weighed (W1). Next, the test piece is immersed in distilled water at 25 ° C. for 24 hours, and after taking out, the water on the surface of the test piece is gently wiped and weighed (W2).
Based on the results of W1 and W2 obtained, the water absorption rate was calculated according to the formula (1).

3) Manufacture of test specimen Polycarbonate film with a thickness of 50 μm [Iupilon FE-2000: manufactured by Mitsubishi Engineering Plastics Co., Ltd. Hereinafter, it is referred to as “FE-2000”. The obtained composition was applied to a thickness of 30 μm with a bar coater.
After FE-2000 was bonded to this with a nip roll, this was repeatedly passed three times under the condition of 120 W / cm, 30 cm from the bottom of the concentrating metal halide lamp at a conveyor speed of 10 m / min. The films were bonded together to produce a laminate film.
The obtained specimen was allowed to stand in a constant temperature and humidity (23 ° C., 50% RH) room for a whole day and night, and then the peel strength and the warpage during bonding were evaluated.

4) The peel strength of the test specimen was measured with a tensile tester under the following conditions under constant temperature and humidity.
-Test piece: 25 mm x 100 mm
・ Peeling angle: 180 degrees ・ Peeling speed: 200 mm / min
In addition, when the adhesive strength was sufficiently strong and the base material was torn at the time of measuring the peel strength, it was described as base material destruction.

5) The warp test specimen at the time of bonding was cut out to a size of 10 cm × 10 cm, left under constant temperature and humidity for 24 hours, and then the height of the warp at the four corners was measured. The numerical values in the table indicate the average height of the four corners. The higher the value, the greater the warp. Based on the measurement results, judgment was made at the following four levels.
A: Less than 0.5 mm (good without warping), O: 0.5 to less than 1.0 mm (slight warping), Δ: 1.0 to less than 1.5 mm (warping), × : Large warpage (1.5mm or more)

6) Heat test The test specimen was cut into a size of 10 cm × 10 cm, and heated at 80 ° C. for 10 minutes in a state where a part (5 × 10 cm) of the test specimen was in contact with the hot plate. The deflection of the test specimen at this time was evaluated by (maximum lifted-minimum height). The higher the value, the greater the deflection. Based on the measurement results, judgment was made at the following four levels.
A: Less than 0.5 mm (good with no deflection), O: 0.5 to less than 1.0 mm (has slight deflection), Δ: 0.5 to less than 1.0 mm (with deflection), × : Large deflection (1.5mm or more)

7) Wet heat test After laminating the obtained composition with FE-2000 to a thickness of 50 μm, under the condition of 120 W / cm, 30 cm from the bottom of the concentrating metal halide lamp, and at a conveyor speed of 10 m / min. Was repeatedly passed 3 times to obtain a cured product.
The initial value of the obtained cured product and the yellow index (YI) 5 days after wet heat (85 ° C. and 90% RH) were measured with an integrating sphere type spectral transmittance measuring device (DOT-3C manufactured by Murakami Color Materials Research Laboratory). It shows that yellowing is so large that the numerical value of change (DELTA) YI (difference between an initial stage and wet heat) of YI is large. Based on the measurement results, judgment was made at the following four levels.
A: << 0.5 (good without coloring), B: 0.5 to 1.0 (slightly colored), Δ: 1.0 to 1.5 (colored), x: 1 .5 or more (large coloring)

The compositions of Examples 1 to 4 all had excellent peel strength, no warp during bonding, no deflection after the heating test, and little yellowing after wet heat.
On the other hand, the compositions of Comparative Examples 1 and 2 that do not contain the component (B) of the present invention did not have warpage during bonding or large deflection after the heating test, but the peel strength was greatly reduced. In addition, the composition of Comparative Example 3 containing the component (B) in excess of the upper limit of 40% by weight of the present invention and not containing the component (C) has excellent peel strength, and the deflection at the time of bonding and after the heating test. Although there was no, yellowing after wet heat was large. Further, the composition of Comparative Example 4 containing the component (C) in excess of the upper limit of 40% by weight of the present invention has excellent peel strength and no deflection after the heating test, but a large warp occurred during bonding. Oops. In addition, the composition of Comparative Example 5, which contains the components (A) to (D) but does not contain any compound having a methacryloyl group, is excellent in peel strength and has no deflection after the heating test, but is large at the time of bonding. Warping has occurred. In addition, the composition of Comparative Example 6 in which the component (B) contains only acrylamide (2) and does not contain acrylamide (1) does not have warpage at the time of bonding or large deflection after the heating test, but has high peel strength. It has fallen.

  According to the adhesive composition of the present invention, excellent adhesive strength can be maintained even at high temperatures, and there is little coloration over time, and between thin-layer adherends such as plastic films used as various optical members. It is effective for laminating and can be suitably used for the production of an optical film particularly used for a liquid crystal display device or the like.

Claims (18)

(A) urethane (meth) acrylate having two or more (meth) acryloyl groups,
(B) a (meth) acrylamide compound containing (meth) acrylamide represented by the following general formula (1) [hereinafter referred to as “(meth) acrylamide (1)”],
(C) a compound having two or more ethylenically unsaturated groups, which is a compound other than the component (A), and (D) a compound having one ethylenically unsaturated group, ) Active energy rays containing a compound other than the component, the component having the components (A) to (D) and a methacryloyl group at the following ratio relative to the total amount of the components (A) to (D): A curable adhesive composition.
(A) component: 5-50 weight%
(B) component: 5 to 40% by weight
Component (C): 5 to 40% by weight
Component (D): 2 to 50% by weight
Compound having methacryloyl group: 5 to 30% by weight

[However, in the general formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. R ² and R ³ in one molecule may be the same group or different groups. ]   The active energy ray-curable adhesive composition according to claim 1, wherein the component (A) is a reaction product of a polyol, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate.   The active energy ray-curable adhesive composition according to claim 1, wherein the component (A) is a non-aromatic urethane (meth) acrylate.   The active energy ray-curable adhesive composition according to claim 1, wherein the component (A) is a urethane (meth) acrylate having a polyester skeleton or a polycarbonate skeleton.   The active energy ray-curable adhesive composition according to claim 1, wherein the component (A) is a urethane (meth) acrylate having a weight average molecular weight of 500 to 50,000. The activity according to any one of claims 1 to 5, wherein the component (B) is a compound in which R ² and R ³ in the formula (1) are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Energy ray curable adhesive composition. (B) The active energy ray hardening-type adhesive composition of any one of Claims 1-6 which contain the compound represented by following General formula (2) in the ratio of 30 weight% or less in a component. object.

[However, in General formula (2), R < ⁴ > represents a hydrogen atom or a methyl group. ]   The active energy ray-curable adhesive composition according to claim 1, wherein the component (C) is a compound having a glass transition temperature of a homopolymer of 100 ° C. or higher.   Furthermore, the active energy ray hardening-type adhesive composition of any one of Claims 1-8 containing (E) photoinitiator.   The active energy ray hardening-type adhesive composition of Claim 9 which contains the said (E) component in the ratio of 0.1-10 weight part with respect to 100 weight part of compositions.   The hardened | cured material of a composition has a glass transition temperature of 60-180 degreeC, The active energy ray hardening-type adhesive composition of any one of Claims 1-10.   The active energy ray-curable adhesive composition according to claim 11, wherein the cured product of the composition has a glass transition temperature of 60 to 180 ° C. and a water absorption of 10% or less.   An adhesive composition for an active energy ray-curable plastic substrate, comprising the composition according to any one of claims 1 to 12.   The adhesive composition for active energy ray hardening-type optical materials which consists of a composition of any one of Claims 1-12.   The adhesive composition for active energy ray hardening-type optical film laminates which consists of a composition of any one of Claims 1-12.   The laminated body comprised from a base material, the hardened | cured material of the composition of any one of Claims 1-12, and another base material.   The laminate according to claim 16, wherein at least one of the substrates is a plastic substrate.   After applying the composition according to any one of claims 1 to 12 to a first substrate and bonding the second substrate to the first substrate, the composition is activated from the surface of any substrate. The manufacturing method of the laminated body characterized by irradiating an energy ray.