JP5652380B2 - Curable adhesive composition - Google Patents

Description

The present invention relates to a curable adhesive composition capable of bonding various substrates by irradiation of active energy rays or heating.
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)

In the above-mentioned adhesive composition for optical film use, the adhesive performance under the above-mentioned high temperature and high humidity conditions is required, and the performance of not coloring or low coloring under high temperature and high humidity conditions is required. Is done.
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 conducted intensive studies to find a curable adhesive composition that is excellent in adhesion performance under high temperature and high humidity conditions, and that is not colored even under high temperature and high humidity conditions or has little coloration. It is.

  As a result of various studies, the present inventors can solve the above problems by using a composition containing an ethylenically unsaturated compound having a glass transition temperature and a water absorption rate of a cured product. The present invention has been completed by finding out what can be done.

The present invention has the following (A) an ethylenically unsaturated group-containing compound [hereinafter referred to as "component (A)". And the cured product has a glass transition temperature (hereinafter referred to as “Tg”) of 60 ° C. or more and a water absorption of 10% or less.

The component (A) includes the following components (a1), (a2) and (a3):
(A) 5 to 60% by weight of component (a1), 5 to 50% by weight of component (a2), and 5 to 60% by weight of component (a3) with respect to the total amount of component (A).
(A1): and one ethylenically unsaturated group, cyclic ether group, a hydroxyl group, a carboxyl group, an imido group, a compound having any one of an amide group and an aromatic group (a2): a urethane (meth) acrylate bets (a3) : a compound having two or more ethylenically unsaturated groups in the molecule and a homopolymer having a glass transition temperature of 100 ° C. or higher

  The composition of the present invention can be preferably used as an active energy ray-curable adhesive composition, and preferably contains (B) a photopolymerization initiator. In this case, what contains the said (B) component in the ratio of 0.1-10 weight part with respect to 100 weight part of compositions is preferable.

  The composition of the present invention preferably further contains (B) a photopolymerization initiator, and preferably contains 0.1 to 10 parts by weight of the component (B) with respect to 100 parts by weight of the composition. .

  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 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.

  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, excellent adhesion performance under high temperature and high humidity conditions, and further under high temperature and high humidity conditions. Is less colored.
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 present invention relates to a curable adhesive composition containing a component (A) and having a cured product having a Tg of 60 ° C. or more and a water absorption of 10% or less.
Hereinafter, (A) component is demonstrated In addition, as (A) component, each compound mentioned later can be used individually, or can also be used in combination of 2 or more types.

1. (A) Component (A) A component is an ethylenically unsaturated group containing compound.
In the component (A), examples of the ethylenically unsaturated group include a (meth) acryloyl group, a vinyl group, and a vinyl ether group, and a (meth) acryloyl group is preferable.

(A) component, lower Symbol (a1), is intended to include (a2) and / or (a3).
(A1) : a compound having one ethylenically unsaturated group and any one of a cyclic ether group, a hydroxyl group, a carboxyl group, an imide group, an amide group and an aromatic group [hereinafter referred to as “component (a1)” ]
(A2) : Urethane (meth) acrylate [hereinafter referred to as “component (a2)”]
(A3) : a compound having two or more ethylenically unsaturated groups in the molecule and having a homopolymer Tg of 100 ° C. or higher (hereinafter referred to as “component (a3)”)
Hereinafter, each component will be described.

1-1. Component (a1) The component (a1) is a compound having one ethylenically unsaturated group and any one of a cyclic ether group, a hydroxyl group, a carboxyl group, an imide group, an amide group, and an aromatic group. By including the component (a1), the adhesion with the substrate can be improved.

  In the component (a1), examples of the compound having a cyclic ether group include tetrahydrofurfuryl (meth) acrylate.

In the component (a1), examples of the compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, and hydroxyhexyl (meth). Hydroxyalkyl (meth) acrylates such as acrylate and hydroxyoctyl (meth) acrylate;
And 2-hydroxy-3-arylpropyl (meth) acrylate such as 2-hydroxy-3-phenoxypropyl (meth) acrylate.

  In the component (a1), examples of the compound having a carboxyl group include (meth) acrylic acid and (meth) acrylic acid dimer and trimer (meth) acrylic acid multimers, monohydroxyethyl (meth) acrylate and ω -Carboxy-polycaprolactone mono (meth) acrylate and the like.

  In the component (a1), examples of the compound having an imide group include N- (meth) acryloyloxyalkyltetrahydrophthalimide such as N- (meth) acryloyloxyethyltetrahydrophthalimide, and N- (meth) acryloyloxyethylhexahydrophthalimide. N- (meth) acryloyloxyalkyl hexahydrophthalimide.

In the component (a1), examples of the compound having an amide group 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 ) Acrylamide, N, N-di -n- butyl (meth) acrylamide, N, N-dihexyl (meth) acrylamide, N, N-dibenzyl (meth) include (meth) acrylamide derivatives such as acrylamide.
Moreover, (meth) acryloyl morpholine is mentioned.
Among these, N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide, which are highly erodible to the substrate, are preferable.

In the component (a1), as the compound having an aromatic group, benzyl (meth) acrylate;
(Meth) acrylates of phenol alkylene oxide adducts such as (meth) acrylates of phenol ethylene oxide adducts and (meth) acrylates of phenol propylene oxide adducts;
And (meth) acrylates of alkylphenol alkylene oxide adducts such as (meth) acrylate of nonylphenol ethylene oxide adduct and (meth) acrylate of nonylphenol propylene oxide adduct.

1-2. (A2) Component (a2) The component is urethane (meth) acrylate. By including the component (a2), the adhesion to the substrate can be improved.
As the component (a2), 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, urethane (meth) acrylate having a polyester skeleton or a polycarbonate skeleton is preferable because the cured product obtained has excellent adhesive strength under high temperature and high humidity conditions.
As the component (a2), 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 (a2) 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.
Moreover, as the component (a2), 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.

As a manufacturing method of (a2) 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.
As the component (a2), those obtained by the production method of 1) above are 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 (a2), 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.
Examples of non-aromatic polyols include non-aromatic polyester polyols and polycarbonate polyols, preferably non-aromatic polyester polyols or non-aromatic polycarbonate polyols that are less colored after wet heat.

1-3. Component (a3) The component (a3) is a compound having two or more ethylenically unsaturated groups in the molecule and having a homopolymer Tg of 100 ° C. or higher. By including the component (a3), the Tg of the cured composition can be increased, and the water absorption can be further decreased.
As Tg of (a3) component, 150 degreeC or more is preferable.
Specific examples of the component (a3) include dimethylol tricyclodecane di (meth) acrylate (Tg of dimethylol tricyclodecane diacrylate = 235 ° C.), trimethylolpropane tri (meth) acrylate (trimethylolpropane triacrylate Tg ≧ 250 ° C.), isocyanuric acid alkylene oxide di- or tri (meth) acrylate [di and triacrylate mixture (Aronix M-313 manufactured by Toagosei Co., Ltd.) Tg ≧ 250 ° C.], bisphenol A type epoxy acrylate [Showa Denko Lipoxy SP-1509, Tg = 117 ° C., Lipoxy SP-4010, Tg ≧ 250 ° C.] is preferable.

1-4. Other components (A) As the component (A), various compounds can be used depending on the purpose in addition to the components (a1), (a2) and (a3) described above. Such compounds include monomers, oligomers and polymers.

1-4-1. Examples of the monomer monomer include a compound having one ethylenically unsaturated group and a compound having two or more ethylenically unsaturated groups.
Examples of the compound having one ethylenically unsaturated group include ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, Examples include 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentanyl (meth) acrylate.
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.

Specific examples of the compound having two or more ethylenically unsaturated groups include ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate and tripropylene glycol di (meth). Alkylene glycol di (meth) acrylates such as 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.

1-4-2. Examples of the oligomer include polyester (meth) acrylate, epoxy (meth) acrylate, and polyether (meth) acrylate.

1-4-2-1. 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”.

1-4-2-2. 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.

1-4-2-3. 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.

1-4-3. 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”.

1-5. Preferred component (A) The present invention, prior to SL (a1), a composition comprising (a2) and (a3) components.
The proportion of the components (a1), (a2) and (a3) is 5 to 60% by weight of the component (a1), 5 to 50% by weight of the component (a2) and (a3) with respect to the total amount of the component (A). ) is a component 5 to 60 wt%, good Mashiku is, (a1) component 10 to 50% by weight and component (a2) 10 to 40% by weight and (a3) component 10 to 50% by weight.
By making the ratio of the component (a1) 5% by weight or more, it can be excellent in adhesiveness, and by making it the other 60% by weight or less, it can be excellent in adhesiveness or at high temperature and high humidity. Under coloration can be suppressed. By making the ratio of the component (a2) 5% by weight or more, the adhesiveness can be excellent, and when it is 50% by weight or less, the adhesiveness can be excellent, or high temperature and high humidity. Under coloration can be suppressed. By setting the proportion of the component (a3) to 5% by weight or less, coloring at high temperature and high humidity can be suppressed by increasing the Tg of the cured product, and on the other hand, the adhesiveness is adjusted to 60% by weight or less. Can be excellent.

2. Other components The composition of the present invention essentially comprises the component (A), but may be used in combination with a photopolymerization initiator, a thermal polymerization initiator or / and other components as necessary. it can.
Hereinafter, each component will be described.

2-1. Photopolymerization initiator The composition of the present invention can be used after being cured by irradiation with active energy rays. Examples of the active energy ray include an electron beam, visible light, and ultraviolet light. A special device is not required, and since it is simple, visible light or ultraviolet light is preferable.
When a visible light or ultraviolet curable composition is used, a photopolymerization initiator [hereinafter also referred to as component (B)] is blended in the composition. In addition, when setting it as an electron beam curable composition, it is not necessary to mix | blend a photoinitiator.

  Component (B) 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.

A preferable blending ratio of the component (B) is 0.1 part by weight or more and 10 parts by weight or less, more preferably 0.5 part by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the composition.
Among these, α-hydroxyacetophenone and phosphine oxide are preferred because the cured product is less colored over time.

2-2. Thermal Polymerization Initiator The composition of the present invention can be thermally cured by blending a thermal polymerization initiator.
Various compounds can be used as the thermal polymerization initiator, and organic peroxides and azo initiators are preferred.
Specific examples of the organic peroxide include 1,1-bis (t-butylperoxy) 2-methylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, , 1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, , 2-bis (4,4-di-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl- , 5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5 -Di (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butyl) Peroxy) valerate, di-t-butylperoxyisophthalate, α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, t-butylcumyl peroxide, di-t-butylperoxide P-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3 Examples include 3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, and t-butyl hydroperoxide.
Specific examples of the azo compound include 1,1′-azobis (cyclohexane-1-carbonitrile), 2- (carbamoylazo) isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile. Azodi-t-octane, azodi-t-butane and the like.
These may be used alone or in combination of two or more. Moreover, an organic peroxide can also be made into a redox reaction by combining with a reducing agent.
The amount of the thermal polymerization initiator used is preferably not more than 10 parts by weight per 100 parts by weight of component (A) or 100 parts by weight of the total amount of component (A) and the radical polymerizable monomer.
When the thermal polymerization initiator is used alone, it may be carried out in accordance with conventional means of normal radical thermal polymerization. In some cases, the thermal polymerization initiator is used in combination with a photopolymerization initiator and photocured for the purpose of further improving the reaction rate. Curing can also be performed.

2-3. Other components In the composition of the present invention, a durability improver such as an antioxidant, an ultraviolet absorber, or a HALS (hindered amine light stabilizer) in an amount of up to 5 parts by weight per 100 parts by weight of the composition. In addition, a leveling agent for making the coating film thickness uniform and an antifoaming agent for suppressing foaming can be added.

3. The active energy ray-curable adhesive composition present invention is (A) the active energy ray-curable curable adhesive composition comprising a component.
The method for producing the composition of the present invention is not particularly limited, and the composition can be obtained by stirring or mixing the essential components of the present invention, or the essential components and other components as necessary, by a commonly used method.
In this case, heating or heating can be performed as necessary.

  The composition of the present invention is a composition having a Tg of a cured product of 60 or more and a water absorption of 10% or less. What the Tg and the water absorption rate of a cured product satisfy | fill the said range has an effect which can suppress coloring of hardened | cured material.

As a composition of this invention, what has Tg of 60-180 degreeC of hardened | cured material is further preferable, More preferably, it is 80-180 degreeC. By setting Tg to 180 ° C. or lower, it is possible to prevent a decrease in initial peel strength.
Further, the composition of the present invention preferably has a water absorption of 5% or less, and can greatly suppress coloring of the cured product.

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.
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 with active energy rays or heating after coating on a substrate.

When the composition of the present invention is an active energy ray-curable composition, examples of the active energy rays include visible light, ultraviolet rays, X-rays, and electron beams, but an inexpensive apparatus can be used. Ultraviolet rays are preferred.
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 3 and Comparative Examples 1 to 4
The components (A 1 ) and (B) shown in Table 1 and Table 2 below were dissolved by heating and stirring at 60 ° C. for 1 hour to produce an active energy ray-curable adhesive composition.
The obtained composition was evaluated according to the following test method.

In Tables 1 and 2, each number in the components (A) and (B) means the number of parts, and each abbreviation has the following meaning.
1) THF-A: Tetrahydrofurfuryl acrylate 2) M-5700: 2-hydroxy-3-phenoxypropyl acrylate [Aronix M-5700 manufactured by Toagosei Co., Ltd.]
3) M-145: N-acryloyloxyethyl-3,4,5,6-tetrahydrophthalimide [Aronix M-145 manufactured by Toagosei Co., Ltd.]
4) UN9200A: Polycarbonate urethane acrylate having a non-aromatic polycarbonate skeleton, weight average molecular weight of about 15,000 [Negami Kogyo Art Resin UN9200A]
5) IBXA: Isobornyl acrylate [Kyoeisha Chemical Co., Ltd. light acrylate IB-XA]
6) M-309: Trimethylolpropane triacrylate [Aronix M-309 manufactured by Toagosei Co., Ltd.]
7) M-313: EO-modified diisocyanate and triacrylate [Aronix M-313 manufactured by Toagosei Co., Ltd.]
8) Irg184: 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184 manufactured by BASF)

○ 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) Heat resistance test After the obtained composition was laminated to a thickness of 50 μm with a polycarbonate film [Iupilon FE-2000: manufactured by Mitsubishi Engineering Plastics Co., Ltd.] having a thickness of 50 μm, 120 W / cm of a concentrating metal halide lamp A cured product was obtained by repeatedly passing under the lamp three times at a position 30 cm from the bottom under the condition of a conveyor speed of 10 m / min.
The yellow index (YI) of the obtained cured product at the initial stage and after 5 days of heat resistance (120 ° C.) was 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: << 1.0 (good without coloring), B: 1.0 to less than 1.5 (slightly colored), Δ: 1.5 to less than 2.0 (colored), x: 2 .0 or more (coloring is large)

4) Moist heat resistance test A cured product was obtained according to the same method as in the heat resistance test.
The initial value of the obtained cured product and the yellow index (YI) after 7 days of wet heat (85 ° C., 90% RH) were measured with an integrating sphere type spectral transmittance meter (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: << 1.0 (good without coloring), B: 1.0 to less than 1.5 (slightly colored), Δ: 1.5 to less than 2.0 (colored), x: 2 .0 or more (coloring is large)

The compositions of Examples 1 to 3 were all excellent in adhesiveness after the heat resistance and moist heat resistance tests, and had little change in coloring.
On the other hand, although the cured product has a water absorption rate that satisfies the present invention, the compositions of Comparative Examples 1 and 2 whose Tg is less than the upper limit of 60 ° C. of the present invention have little color change in the moist heat resistance test. The coloration in the test changed greatly. Further, the composition of Comparative Example 3 in which the Tg of the cured product was less than the upper limit of 60 ° C. of the present invention and the water absorption exceeded 10% of the upper limit of the present invention was greatly changed in coloring in the heat resistance and moist heat resistance tests. Further, although the Tg of the cured product satisfies the present invention, the composition of Comparative Example 4 having a water absorption rate exceeding the upper limit of 10% of the present invention has little color change in the heat resistance test, but has a color change in the moist heat resistance test. It was big.

  According to the adhesive composition of the present invention, it has excellent adhesiveness even under high temperature and high humidity conditions, and is less colored even under high temperature and high humidity conditions, such as plastic films used as various optical members. It is effective for laminating and adhering thin-layer adherends, and can be suitably used for the production of optical films used particularly for liquid crystal display devices.

Claims (8)

(A) comprises an ethylenically unsaturated group-containing compound state, and are 60 ° C. or higher and a water absorption of less than 10% Glass transition temperature of the cured product,
The component (A) includes the following components (a1), (a2) and (a3)
(A) 5 to 60% by weight of component, (a2) 5 to 50% by weight of component, and (a3) 5 to 60% by weight of component, with respect to the total amount of component,
Active energy ray- curable adhesive composition.
(A1): Compound having one ethylenically unsaturated group and any one of cyclic ether group, hydroxyl group, carboxyl group, imide group, amide group and aromatic group
(A2): Urethane (meth) acrylate
(A3): a compound having two or more ethylenically unsaturated groups in the molecule and having a homopolymer having a glass transition temperature of 100 ° C. or higher Further, (B) an active energy ray-curable adhesive composition according to claim 1 comprising a photopolymerization initiator. The active energy ray hardening-type adhesive composition of Claim 2 which contains the said (B) component in the ratio of 0.1-10 weight part with respect to 100 weight part of compositions. The active energy ray hardening-type adhesive composition for plastic base materials which consists of a composition of any one of Claims 1-3 . The active energy ray hardening-type adhesive composition for optical film laminates which consists of a composition of any one of Claims 1-3 . The laminated body comprised from a base material, the hardened | cured material of the composition of any one of Claims 1-3 , and another base material. The laminate according to claim 6 , wherein at least one of the substrates is a plastic substrate. The composition according to any one of claims 1 to 3 was applied to the first substrate, after attaching the second substrate to the active from the surface of any substrate The manufacturing method of the laminated body characterized by irradiating an energy ray.