WO2012141275A1 - Active energy ray-curable adhesive composition - Google Patents

Abstract

[Problem] The purpose of the invention is to provide an active energy ray-curable adhesive composition with which adhesiveness to a substrate is excellent, there is little warping over time of the resulting laminate, and there is little bending after heat testing. [Solution] The active energy ray-curable adhesive composition is a composition comprising (A) a urethane (meth)acrylate, (B) a (meth)acrylamide compound that contains a compound represented by formula (1) and a compound represented by formula (2) in amounts, per a total of 100 parts by weight (parts hereafter), that are between 5 and 95 parts and 95 and 5 parts, respectively, and (C) a compound having ethylenic unsaturated groups other than components (A) and (B), wherein the ratio of components (A) through (C) per the total amount of components (A) through (C) is 5 to 50 wt% (% hereafter) of component (A), 30 to 93% of component (B), and 2 to 65% of component (C) and the ratio of compounds having methacryloyl groups is 2 to 30% of the total of components (A) through (C).

Description

Active energy ray-curable adhesive composition

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 is bonded to a thin-layer adherend made of another material, 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.

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.
In addition to the adhesive composition described above, active energy ray-curable adhesive compositions using urethane (meth) acrylate and (meth) acrylamide compounds in combination are known (Patent Documents 4 to 6).

JP 2000-072833 A JP 2001-064594 A International Publication No. 2006/118078 Pamphlet JP-A-9-157317 JP 7-310067 A JP 2007-177169 A

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.

Further, as a result of the study by the present inventors, in the compositions described in Patent Documents 4 to 6, when the obtained laminate has little warpage and deflection, the adhesive strength may be insufficient, When the obtained laminate had no warpage and excellent adhesive strength, the deflection was increased, and the obtained laminate had little warpage and deflection, and none had excellent adhesive strength.

Therefore, the present inventors have found an active energy ray-curable adhesive composition that has excellent adhesive strength, little warpage in the resulting laminate, and little film laminate deflection even under partially heated conditions. For this reason, we conducted an intensive study.

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, component (A): urethane (meth) acrylate [hereinafter referred to as “component (A)”. ],
Component (B): a compound represented by the following formula (1) [hereinafter referred to as “(meth) acrylamide (1)”) and a compound represented by the following formula (2) [hereinafter referred to as “(meth) acrylamide (2 ) ”And 95 to 5 parts by weight of (meth) acrylamide (1) and (meth) acrylamide (1) 5 with respect to 100 parts by weight of the total amount of (meth) acrylamide (1) and (2) A (meth) acrylamide compound comprising ˜95 parts by weight [hereinafter referred to as “component (B)”. ], And
Component (C): Compound having an ethylenically unsaturated group other than the components (A) and (B) [hereinafter referred to as “component (C)”. ]
A composition comprising:
(A) to (C) component is included in the following proportion with respect to the total amount of components (A) to (C):
Component (A): 5 to 50% by weight
Component (B): 30 to 93% by weight
Component (C): 2 to 65% by weight
An active energy ray-curable adhesive composition containing 2 to 30% by weight of a compound having a methacryloyl group in the total of components (A) to (C) [hereinafter simply referred to as “the adhesive composition of the present invention”] Or “the composition of the present invention”).

As the component (A), non-aromatic urethane (meth) acrylate is preferable. As the component (A), urethane (meth) acrylate having 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), (meth) acrylamide (1) is in the after-mentioned formula (1), the compound R ² and R ³ are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms are preferred.

The composition of the present invention preferably further contains (D) a photopolymerization initiator, and preferably contains 0.1 to 10 parts by weight of the component (D) with respect to 100 parts by weight of the composition. .
The composition of the present invention preferably has a cured product having a glass transition temperature of 60 to 180 ° C.

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.

Further, the present invention is a process of applying any one of the above compositions to the first substrate,
Bonding the second substrate to the composition;
It is a manufacturing method of the laminated body including the process of irradiating an active energy ray from the 1st base material or the 2nd base material side.
As a 1st base material or a 2nd base material, it is preferable that at least one is a plastic base material, it is preferable that it is an optical member, and it is preferable that it is an optical film.

Furthermore, the present invention also relates to a laminate composed of a first substrate, a cured product of the above-described composition, and a second substrate. As the first base material or the second base material, at least one is preferably a plastic base material.

According to the composition of the present invention, the active energy is excellent in adhesion to a substrate, particularly excellent in adhesion to a plastic substrate, and the resulting laminate has little warping with time, and further has little deflection after a heating test. A wire curable adhesive composition can be provided.
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), (B) and (C) as essential components.
Hereinafter, each component will be described.
As the components (A) to (C), each compound described later can be used alone, or two or more compounds can be used in combination.

1. (A) Component (A) A component is urethane (meth) acrylate.
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, and a urethane having a polycarbonate skeleton (more preferably a urethane ( (Meth) acrylate.
As the component (A), any of oligomers and polymers can be used, preferably having a weight average molecular weight of 500 to 50,000, more preferably 3,000 to 50,000, and particularly preferably 10,000 to 40,000.
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 preferably a urethane (meth) acrylate having two (meth) acryloyl groups (hereinafter also referred to as a bifunctional urethane (meth) acrylate), and is a polyester, polyether or polycarbonate skeleton. More preferred is a bifunctional urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylate with a reaction product of a diol having 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 and 1,6-hexanediol.
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 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.
Non-aromatic polyols include non-aromatic polyester polyols and polycarbonate polyols, and preferably non-aromatic polycarbonate polyols.

2. (B) component (B) component contains (meth) acrylamide (1) and (meth) acrylamide (2), and (meth) acrylamide (1) and (2) with respect to a total amount of 100 parts by weight, ) A (meth) acrylamide compound comprising 5 to 95 parts by weight of acrylamide (1) and 95 to 5 parts by weight of (meth) acrylamide (2).
In the present invention, by including the component (B), the adhesion to the substrate can be improved and the glass transition temperature of the composition cured product can be increased. Can be prevented.

(Meth) acrylamide (1) is a compound represented by the following formula (1).

In [Equation (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 a carbon number of 1 ~ 20, R ² and R ³ in one molecule These 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.

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) ac Ruamido, 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) is used in combination with (meth) acrylamide (1) represented by the following formula (2) in addition to (meth) acrylamide (1), so that the erodibility to the substrate is not inhibited. And the bending of the obtained laminated body under a heating condition can be reduced.

In [the formula (2), R ⁴ represents a hydrogen atom or a methyl group. ]

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

The proportion of (meth) acrylamide (1) and (2) in the component (B) is (meth) acrylamide (1) 5 to 95 with respect to 100 parts by weight of the total amount of (meth) acrylamide (1) and (2). It is composed of 95 to 5% by weight of (meth) acrylamide (2) by weight, preferably 10 to 90% by weight of (meth) acrylamide (1) and 90 to 10% by weight of (meth) acrylamide (2). When the proportion of (meth) acrylamide (1) is less than 5% by weight or the proportion of (meth) acrylamide (2) exceeds 95% by weight, the adhesive strength is lowered. On the other hand, if the proportion of (meth) acrylamide (1) exceeds 95% by weight or the proportion of (meth) acrylamide (2) is less than 5% by weight, the deflection of the laminate obtained under heating conditions will be It gets bigger.

3. Component (C) The component (C) is a compound having an ethylenically unsaturated group other than the components (A) and (B).
As the component (C), various compounds can be used as long as they are compounds other than the components (A) and (B). As the component (C), there are monomers, oligomers and polymers.

3-1. Examples of the monomer monomer include compounds having one (meth) acryloyl group.
Examples of the compound include ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Alkyl (meth) acrylates; aromatic group-containing (meth) acrylates such as benzyl (meth) acrylate; alicyclic groups such as isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate and dicyclopentanyl (meth) acrylate Containing (meth) acrylates; and hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate
In addition to (meth) acrylates, N-vinyl compounds such as N-vinylpyrrolidone and N-vinylcaprolactam can be used.
Examples of the compound having two or more (meth) acryloyl groups include ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate. Alkylene glycol di (meth) acrylate; glycol di (meth) acrylate such as 1,6-hexanediol di (meth) acrylate and neopentyl glycol di (meth) acrylate; bisphenol A di (meth) acrylate or a halogen nucleus substitution product thereof And bisphenol-type di (meth) acrylates such as bisphenol F di (meth) acrylate or a halogen nucleus substitution product thereof; dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane Poly (poly) acrylates such as li (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate; Poly (meth) acrylates of alkylene oxide adducts; di- or tri (meth) acrylates of isocyanuric acid alkylene oxides; in addition to these, the document "Latest UV Curing Technology" [printed information association, published in 1991] And the like as described on pages 53 to 56.

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 a 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 its anhydride, dibasic acid such as orthophthalic acid, isophthalic acid, terephthalic acid, adipic acid, succinic acid, fumaric acid, maleic acid, hexahydrophthalic acid, tetrahydrophthalic acid and trimellitic acid or anhydrous Thing etc. are mentioned.
Examples of polyester poly (meth) acrylates 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 on 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 Examples thereof include novolak-type epoxy resins such as epoxy resins; glycidyl phthalimide; o-phthalic acid diglycidyl ester and the like.
In addition to these, the document “Epoxy Resin-Recent Advances” (Shojodo, published in 1990), Chapter 2 and the document “Polymer Processing”, Vol. 9, Volume 22, Epoxy Resin [Polymer Press, Compounds published on pages 4 to 6 and 9 to 16 of 1973.

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 its alkylene oxide adducts; di- or triglycidyl ethers of trimethylolethane, trimethylolpropane, glycerin and its alkylene oxide adducts; 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 as a skeleton, for example, TEPIC (Nissan Chemical Co., Ltd.), Denacol EX-310 (Nagase Kasei Co., Ltd.), etc. can be mentioned. And compounds described on pages 289 to 296 of the above-mentioned document “Polymer Processing”, separate volume epoxy resin.
In the above, the alkylene oxide of the alkylene oxide adduct is preferably ethylene oxide or propylene oxide.

3-2-3. Polyether (meth) acrylate oligomer Polyether (meth) acrylate oligomers include polyalkylene glycol (meth) diacrylate, 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”.

The compound of component (C) is preferably selected so that the glass transition temperature of the cured product of the composition described below falls within a preferred range.
(C) As a component, the monomer which has one (meth) acryloyl group is preferable at the point which adhesiveness is favorable also in an above described compound.
Further, the component (C) is preferably a compound having a glass transition temperature (hereinafter referred to as “Tg”) of the homopolymer of 0 to 200 ° C., more preferably 60 to 180 ° C. Examples of the compound include dicyclopentanyl acrylate (Tg of homopolymer: 120 ° C., hereinafter the parentheses have the same meaning), dicyclopentanyl methacrylate (175 ° C.), isobornyl acrylate (94 ° C.). And isobornyl methacrylate (180 ° C.).
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.

4). In the present invention, the proportions of the components (A), (B) and (C) are 5 to 50% by weight of component (A) with respect to the total amount of components (A) to (C), (B ) Component 30 to 93% by weight and (C) component 2 to 65% by weight, preferably (A) component 15 to 40% by weight, (B) component 30 to 85% by weight and (C) component 2 to 55%. % 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 of the laminate obtained under heating conditions is increased. When the component (B) is less than 30% by weight or when the component (B) exceeds 93% by weight, the adhesive strength is reduced in any case. When the amount of component (C) is more than 65% by weight, the adhesive strength is reduced. By making the component (C) 2% by weight or more, the adhesive strength can be made excellent.

The composition of the present invention needs to contain 2 to 30% by weight of the compound having a methacryloyl group in the total of the components (A) to (C), preferably 5 to 30% by weight, Preferably, it is 5 to 25% by weight. When the amount is less than 2% by weight, warping may occur at the time of bonding, and when it 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-mentioned (A), (B) and (C) component. As the compound having a methacryloyl group, it is convenient and preferable to select a compound having a methacryloyl group from the component (C).

5. Other Components When the composition of the present invention is cured by ultraviolet rays, a photopolymerization initiator [hereinafter also referred to as component (D)] can be blended as necessary.
Component (D) 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 Acetophenones such as acetophenone, 1,1-dichloroacetophenone, 1-hydroxyacetophenone, 1-hydroxycyclohexyl phenyl ketone and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one; 2 -Anthraquinones such as methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone; 2,4-dimethylthioxan Thioxanthone such as 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like Monoacylphosphine 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.
The preferred blending ratio of component (D) is 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the composition.
Among these, α-hydroxyacetophenones and phosphine oxides 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 (C). In addition, a leveling agent for making the coating film thickness uniform and an antifoaming agent for suppressing foaming can be added.

6). 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.
The composition of the present invention can be preferably used as a solvent-free composition containing no organic solvent. As a result, a large amount of solvent vapor is volatilized during the drying of the organic solvent, and the problems of toxicity, work safety and environmental pollution can be avoided, and further, the heat energy used for drying is not required. The product can be manufactured at a low cost.

As the composition of the present invention, a cured product having a Tg of 60 to 180 ° C. is preferable. When the Tg is 60 ° C. or higher, the adhesive strength at the time of the heat resistance test is excellent, and when the Tg is 180 ° C. or lower, the initial peel strength is sufficiently obtained.

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. Is preferably one having an energy of 50 to 1,000 eV, more preferably 100 to 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 are used. 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 6 and Comparative Examples 1 to 5
The components (A), (B), (C) and (D) 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) to (D) means the number of parts, and each abbreviation has the following meaning.
1) UN9200A: Polycarbonate urethane acrylate having a non-aromatic polycarbonate skeleton, weight average molecular weight of about 20,000 [Negami Kogyo Co., Ltd. Art Resin UN9200A]
2) OT-1001: Polyester urethane acrylate having a non-aromatic polyester skeleton, weight average molecular weight of about 40,000 [Aronix OT-1001 manufactured by Toagosei Co., Ltd.]
3) KY-303: Polyether urethane acrylate, weight average molecular weight of about 15,000 [KY-303 manufactured by Negami Kogyo Co., Ltd.]
4) DMAA: N, N-dimethylacrylamide [DMAA manufactured by Kojin Co., Ltd.]
5) DEAA: N, N-diethylacrylamide [DEAA manufactured by Kojin Co., Ltd.]
6) ACMO: acryloyl morpholine [ACMO manufactured by Kojin Co., Ltd.]
7) IBX: Isobornyl methacrylate [Light acrylate IB-X manufactured by Kyoeisha Chemical Co., Ltd.]
8) BzMA: benzyl methacrylate 9) IBXA: isobornyl acrylate [Kyoeisha Chemical Co., Ltd. light acrylate IB-XA]
10) M-111: Nonylphenol ethylene oxide modified acrylate [Aronix M-111 manufactured by Toagosei Co., Ltd.]
11) FA-513M: Dicyclopentanyl methacrylate [Hanchlor FA-513M manufactured by Hitachi Chemical Co., Ltd.]
12) FA-513AS: Dicyclopentanyl acrylate [Fanacryl FA-513AS manufactured by Hitachi Chemical Co., Ltd.]
13) Irg184: 1-hydroxycyclohexyl phenyl ketone (Irgacure 184 manufactured by BASF)
14) TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide [Lucirin TPO manufactured by BASF]
15) Ratio of MA: Ratio of compound having a methacryloyl group to the total amount of components (A) to (C) (unit: wt%)
16) M-120: 2-ethylhexyl ethylene oxide modified acrylate [Aronix M-120 manufactured by Toagosei Co., Ltd.]
17) OPPA: Orthophenylphenol acrylate [Aronix TO-2344 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) Production of Specimen The obtained composition was applied to a thickness of 10 μm by a bar coater on a polycarbonate (hereinafter abbreviated as PC) film (Iupilon FE-2000: manufactured by Mitsubishi Engineering Plastics Co., Ltd.) having a thickness of 50 μm. .
A 50 μm-thick PC film was bonded to this by a nip roll, and this was done 3 times under the lamp at 120 W / cm, 30 cm from the bottom of the concentrating metal halide lamp at a conveyor speed of 10 m / min. Passing repeatedly, the films were bonded together to produce a laminated 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.

3) 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.
The unit of measurement of peel strength: gram weight / inch (gf / inch) is 1 (gf / inch) = 3.86 × 10 ⁻³ (N / cm).

4) 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 one day and night, 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), B: 0.5 mm or more and less than 1.0 mm (slight warping), C: 1.0 mm or more and less than 1.5 mm (warping), D: Warpage Is large (1.5mm or more)

5) Heat test specimen was cut into a size of 10 cm × 10 cm, and heated at 80 ° C. for 10 minutes or 120 ° C. for 10 minutes with a part (5 × 10 cm) of the test specimen in contact with a hot plate. The deflection of the 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), B: 0.5 mm or more and less than 1.0 mm (slight deflection), C: 1.0 mm or more and less than 1.5 mm (with deflection), D: Deflection Is large (1.5mm or more)

The compositions of Examples 1 to 6 were all excellent in peel strength, free from warpage during bonding, and free from deflection after the heating test.
On the other hand, the composition of Comparative Example 1 containing no component (B) had excellent peel strength and no warpage during bonding, but a large deflection occurred after the heating test. In addition, the composition of Comparative Example 2 that does not contain acrylamide (1), which is an essential component of the component (B) of the present invention, has a large decrease in peel strength, although there was no warpage at the time of bonding or deflection after a heating test. have done. In addition, the composition of Comparative Example 3, which contains the components (A) to (C) but does not contain any compound having a methacryloyl group, has excellent peel strength and no deflection after the heating test, Warping has occurred. The composition of Comparative Examples 4 and 5 which does not contain acrylamide (2) in the component (B) was obtained after a more severe heating test at 120 ° C., although it had excellent peel strength and no warpage during bonding. A large deflection has occurred in the laminate.

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 (17)

1. (A) component: urethane (meth) acrylate,
   Component (B): a compound represented by the following formula (1) [hereinafter referred to as “(meth) acrylamide (1)”] and a compound represented by the following formula (2) [hereinafter referred to as “(meth) acrylamide (2)” ) ”, And 5 to 95 parts by weight of (meth) acrylamide (1) and (meth) acrylamide (1) with respect to 100 parts by weight of the total amount of (meth) acrylamide (1) and (2). A (meth) acrylamide compound comprising 95 to 5 parts by weight, and
   (C) component: a composition comprising a compound having an ethylenically unsaturated group other than the components (A) and (B),
   (A) to (C) component is included in the following proportion with respect to the total amount of components (A) to (C):
   Component (A): 5 to 50% by weight
   Component (B): 30 to 93% by weight
   Component (C): 2 to 65% by weight
   An active energy ray-curable adhesive composition comprising 2 to 30% by weight of a compound having a methacryloyl group in the total of the components (A) to (C).
   

   

   In [Equation (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 a carbon number of 1 ~ 20, R ² and R ³ in one molecule These may be the same group or different groups. ]
   

   

   In [the formula (2), R ⁴ represents a hydrogen atom or a methyl group. ]
2. 2. The active energy ray-curable adhesive composition according to claim 1, wherein the component (A) is a non-aromatic urethane (meth) acrylate.
3. The active energy ray-curable adhesive composition according to claim 1 or 2, wherein the component (A) is a urethane (meth) acrylate having a polycarbonate skeleton.
4. The active energy ray-curable adhesive composition according to any one of claims 1 to 3, wherein the component (A) is urethane (meth) acrylate having a weight average molecular weight of 500 to 50,000.
5. The activity according to any one of claims 1 to 4, wherein the compound represented by the formula (1) is a compound in which R ² and R ³ are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Energy ray curable adhesive composition.
6. The active energy ray-curable adhesive composition according to any one of claims 1 to 5, further comprising (D) a photopolymerization initiator.
7. The active energy ray-curable adhesive composition according to claim 6, comprising 0.1 to 10 parts by weight of the component (D) with respect to 100 parts by weight of the composition.
8. The active energy ray-curable adhesive composition according to any one of claims 1 to 7, wherein the cured product of the composition has a glass transition temperature of 60 to 180 ° C.
9. The active energy ray-curable adhesive composition according to any one of claims 1 to 8, which is used for a plastic substrate.
10. The active energy ray-curable adhesive composition according to any one of claims 1 to 8, which is used for an optical material.
11. The active energy ray-curable adhesive composition according to any one of claims 1 to 8, which is used for optical film lamination.
12. A step of applying the composition according to any one of claims 1 to 11 to a first base material A step of bonding a second base material to the composition The first base material or the second base material The manufacturing method of the laminated body including the process of irradiating an active energy ray from the base material side.
13. The method for producing a laminate according to claim 12, wherein at least one of the first substrate and the second substrate is a plastic substrate.
14. The method for producing a laminate according to claim 12, wherein at least one of the first substrate and the second substrate is an optical member.
15. The method for producing a laminate according to claim 12, wherein at least one of the first substrate and the second substrate is an optical film.
16. A laminate comprising a first substrate, a cured product of the composition according to any one of claims 1 to 11, and a second substrate.
17. The laminate according to claim 16, wherein at least one of the first substrate and the second substrate is a plastic substrate.