JP5978776B2 - Curable composition, adhesive, laminated film and solar cell backsheet - Google Patents

Description

  The present invention relates to a curable composition, an adhesive, a laminated film, and a solar cell backsheet that are excellent in substrate adhesion under wet heat conditions.

  In recent years, photovoltaic power generation has attracted attention as a representative of clean energy. The back sheet installed on the back of the solar cell module is a member for protecting the power generation mechanism such as cells and wiring from the external environment and maintaining insulation, and various functional films are bonded together with adhesives. It consists of a laminate. Adhesives used for such backsheets maintain high adhesion to various films with different characteristics such as polyester film, polyvinyl fluoride film, metal foil, etc., and maintain long-term adhesion even in open-air environments. Therefore, a high level of moisture and heat resistance is required.

  A number average molecular weight (Mn) obtained by reacting polyester diol, isophorone diisocyanate, and hydroxyethyl acrylate obtained by reacting 3-methylpentanediol and adipic acid as a curable composition excellent in adhesiveness of various films 7,138, a resin composition containing a urethane acrylate having a hydroxyl value of 7.9, phenoxyethyl acrylate, isobornyl acrylate, and a nurate polyisocyanate of hexamethylene diisocyanate (see Patent Document 1), and a number average molecular weight (Mn) Weight average molecular weight (Mw) of 83,000 obtained by reacting 3,000 polyester diol, cyclohexanedimethanol, diacrylate of propylene glycol diglycidyl ether, and isophorone diisocyanate 0 of urethane acrylate, epoxy resin, aziridine compound, and a resin composition comprising a pentaerythritol triacrylate (see Patent Document 2) are known. Although these resin compositions have high initial adhesive strength, the main component of urethane acrylate is an aliphatic structure, so the hydrophobicity is not sufficient, and the adhesive strength is significantly reduced under wet heat conditions. It was something that would end up.

JP 2008-169319 A JP 2011-21173 A

  Therefore, the problem to be solved by the present invention is to provide a curable composition capable of maintaining high adhesiveness even under wet heat conditions, an adhesive comprising the composition, and a laminate having an adhesive layer comprising the adhesive The object is to provide a backsheet for a film and a solar cell.

  As a result of intensive studies to solve the above problems, the present inventors have found a composition containing a hydroxyl group-containing (meth) acrylate using a polyester polyol having an aromatic ring in the molecular structure as a raw material and a polyisocyanate compound. The present invention has been found to be excellent in adhesiveness to various types of films, maintain high adhesiveness even under wet heat conditions, and that the composition can be suitably used for a solar cell backsheet. It came to complete.

  That is, the present invention includes urethane (meth) acrylate (A) having an aromatic ring-containing polyester skeleton and a hydroxyl group in the molecular structure, and an aromatic ring content in the range of 1.0 to 4.0 mmol / g. The present invention relates to a curable composition comprising a polyisocyanate compound (B) and a radical polymerization initiator (C) as essential components.

  The present invention further relates to an adhesive comprising the composition.

  The present invention further relates to a laminated film having an adhesive layer made of the adhesive.

  The present invention further relates to a solar cell backsheet having an adhesive layer made of the adhesive.

  According to the present invention, compared with the conventional adhesive composition, a curable composition that has excellent adhesion to various types of films and can maintain high adhesion even under wet heat conditions, and the resin composition , A laminated film having an adhesive layer made of the adhesive, and a solar cell backsheet.

  The curable composition of the present invention comprises urethane (meth) acrylate (A) having an aromatic ring-containing polyester skeleton and a hydroxyl group in the molecular structure, a polyisocyanate compound (B), and a radical polymerization initiator (C) as essential components. Contained as. Such a resin composition can instantly cure the (meth) acryloyl group of the urethane (meth) acrylate (A) by irradiation with active energy rays to form a B-stage, and further heat or normal temperature. Curing in can cure the hydroxyl group possessed by the urethane (meth) acrylate (A) and the isocyanate group possessed by the polyisocyanate compound (B), thereby making it possible to bond various types of films more firmly. On the other hand, in the case of the resin composition having only the (meth) acryloyl group, since it is cured only by irradiation with active energy rays, the production of the laminated film becomes very simple, but the adhesiveness is inferior. In addition, in the case of a resin composition having only a urethane curing system of a hydroxyl group and an isocyanate group, although it is excellent in final adhesion, curing for several days is necessary to obtain high adhesion, so Production efficiency is greatly reduced.

  The urethane (meth) acrylate (A) used in the present invention has an aromatic ring-containing polyester skeleton in the molecular structure, thereby improving the hydrophobicity of the cured product. Sex can be maintained. Since the content of the aromatic ring of the urethane (meth) acrylate (A) is in the range of 1.0 to 4.0 mmol / g, the initial adhesive force is high, and it is excellent in maintaining adhesiveness under wet heat conditions. 1.2 to 3.8 mmol / g, and more preferably 1.6 to 3.2 mmol / g.

  Such urethane (meth) acrylate (A) includes, for example, polyester polyol (a1) having an aromatic ring in the molecular structure, polyisocyanate compound (a2), and (meth) acrylate compound having a hydroxyl group in the molecular structure. Urethane (meth) acrylate (A1) obtained by reacting (a3), polyester polyol (a4) having an aromatic ring in the molecular structure, and (meth) acrylate compound (a5) having an isocyanate group in the molecular structure ) And urethane (meth) acrylate (A2) obtained by reacting.

  Urethane (meth) acrylate obtained by reacting polyester polyol (a1) having an aromatic ring in the molecular structure, polyisocyanate compound (a2), and (meth) acrylate compound (a3) having a hydroxyl group in the molecular structure (A1) will be described.

  The polyester polyol (a1) used as a raw material for the urethane (meth) acrylate (A1) is, for example, an aromatic ring in at least one of the polyol and the polybasic acid among the polyester polyols obtained by reacting the polyol with the polybasic acid. What is obtained using a containing compound is mentioned. One kind of the polyester polyol may be used alone, or a plurality of kinds having different compositions may be used in combination.

  Examples of the polyol used as a raw material for the polyester polyol (a1) include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, and 2,2-dimethyl. -3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1, Aliphatic diols such as 5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis (hydroxymethyl) cyclohesane, 2,2,4-trimethyl-1,3-pentanediol;

  Ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol;

  Polycyclic polymers obtained by ring-opening polymerization of the aliphatic diols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether. Ether-modified diols;

  A lactone polyester diol obtained by a polycondensation reaction between the aliphatic diol and various lactones such as ε-caprolactone;

  Bisphenols such as bisphenol A and bisphenol F;

  Alkylene oxide adducts of bisphenol obtained by adding ethylene oxide, propylene oxide, etc. to bisphenols such as bisphenol A and bisphenol F;

  Trifunctional or higher functional aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, pentaerythritol;

  3 obtained by ring-opening polymerization of the aliphatic polyol and various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether. Functional or higher polyether-modified polyols;

  Examples thereof include lactone polyester polyols obtained by a polycondensation reaction between the aliphatic polyol and various lactones such as ε-caprolactone. These may be used alone or in combination of two or more.

  Examples of the polybasic acid used as a raw material for the polyester polyol (a1) include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and tridecane. Aliphatic dibasic acids such as diacid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, icosanedioic acid;

  Aliphatic unsaturated dibasic acids such as tetrahydrophthalic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, glutaconic acid and the anhydrides thereof;

  Alicyclic dibasic acids such as hexahydrophthalic acid and 1,4-cyclohexanedicarboxylic acid;

  Aromatic dibasic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid and their anhydrides;

  Aliphatic tribasic acids such as 1,2,5-hexanetricarboxylic acid and 1,2,4-cyclohexanetricarboxylic acid;

  Examples thereof include aromatic tribasic acids such as trimellitic acid, trimellitic anhydride, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, and anhydrides thereof. These may be used alone or in combination of two or more.

  The polyester polyol (a1) can be obtained, for example, by reacting these polyol and polybasic acid in the temperature range of 140 to 270 ° C. in the presence of an esterification catalyst.

  The aromatic ring content of the polyester polyol (a1) is in the range of 1.5 to 4.5 mmol / g because a curable composition having excellent heat and moisture resistance and high initial adhesive strength can be obtained. Preferably, it is in the range of 2.0 to 3.5 mmol / g.

  Further, since the number average molecular weight (Mn) of the polyester polyol (a1) is excellent in adhesion to various types of films, a resin composition capable of maintaining high adhesion even under wet heat conditions is obtained. Is preferably in the range of 1,000 to 10,000, and more preferably in the range of 2,000 to 7,000.

  In the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are values measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

  Examples of the polyisocyanate compound (a2) used as a raw material for the urethane (meth) acrylate (A1) include various diisocyanate compounds, adduct-type polyisocyanate compounds having a urethane bond site in the molecular structure, and isocyanurates in the molecular structure. Examples thereof include a nurate type polyisocyanate compound having a ring structure.

  Examples of the diisocyanate compound include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, and m-tetramethylxylylene. Aliphatic diisocyanates such as range isocyanate;

  Cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4′-diisocyanate, Alicyclic diisocyanates such as norbornane diisocyanate;

  1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate And aromatic diisocyanates such as 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, and the like.

  The adduct type polyisocyanate compound having a urethane bond site in the molecular structure can be obtained, for example, by reacting the diisocyanate compound with a trifunctional or higher functional polyol. Examples of the diisocyanate compound used in the reaction include the various diisocyanate compounds described above. These may be used alone or in combination of two or more. Examples of the tri- or higher functional polyol used in the reaction include the polyol exemplified as the raw material of the polyester polyol (a1), the polyester polyol obtained by reacting a polyhydric alcohol and a polybasic acid, and the like. Each may be used alone or in combination of two or more.

  The nurate polyisocyanate compound having an isocyanurate ring structure in the molecular structure can be obtained, for example, by reacting a diisocyanate compound with a monoalcohol or diol. Examples of the diisocyanate compound used in the reaction include the various diisocyanate compounds described above. These may be used alone or in combination of two or more. The monoalcohol used in the reaction is hexanol, 2-ethylhexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-hepta. Decanol, n-octadecanol, n-nonadecanol, eicosanol, 5-ethyl-2-nonanol, trimethylnonyl alcohol, 2-hexyldecanol, 3,9-diethyl-6-tridecanol, 2-isoheptylisoundecanol, Examples include 2-octyldodecanol and 2-decyltetradecanol. Examples of the diol include the diols exemplified as the raw material of the polyester polyol (a1). These monoalcohols and diols may be used alone or in combination of two or more.

  In addition, when using a polyisocyanate compound having a functionality or higher, such as an adduct type polyisocyanate compound having a urethane bond site in the molecular structure or a nurate type polyisocyanate compound having an isocyanurate ring structure in the molecular structure, the isocyanate group of the compound The content is preferably in the range of 7 to 25% by mass because a resin composition that is more excellent in adhesiveness under wet heat conditions can be obtained.

  These polyisocyanate compounds (a2) may be used alone or in combination of two or more.

  The (meth) acrylate compound (a3) having a hydroxyl group in the molecular structure as a raw material of the urethane (meth) acrylate (A1) is, for example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, Aliphatic (meth) acrylate compounds such as glycerin diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate;

  4-hydroxyphenyl acrylate, β-hydroxyphenethyl acrylate, 4-hydroxyphenethyl acrylate, 1-phenyl-2-hydroxyethyl acrylate, 3-hydroxy-4-acetylphenyl acrylate, 2-hydroxy-3-phenoxy Examples include (meth) acrylate compounds having an aromatic ring in the molecular structure such as propyl acrylate. These may be used alone or in combination of two or more. Among them, the aliphatic (meth) acrylate compound is preferable because it has excellent adhesion to various films and can maintain high adhesion even under wet heat conditions, and is preferably 2-hydroxyethyl acrylate, 2-hydroxy Mono (meth) acrylate compounds such as propyl acrylate and 4-hydroxybutyl acrylate are more preferable.

  The urethane (meth) acrylate (A1) is, for example, a polyester polyol (a1) having an aromatic ring in the molecular structure, the polyisocyanate compound (a2), and a (meth) acrylate compound having a hydroxyl group in the molecular structure. Examples thereof include a method in which (a3) is reacted in the temperature range of 40 to 120 ° C. in the presence of a urethanization catalyst. At this time, a method of reacting these three raw materials at once may be used, or after reacting the polyester polyol (a1) and the polyisocyanate compound (a2) first, the molecular structure has a hydroxyl group (meth). The acrylate compound (a3) may be reacted, or the polyisocyanate compound (a2) may be reacted with the (meth) acrylate compound (a1) having a hydroxyl group in the molecular structure before the polyester. A method of reacting the polyol (a1) may be used.

  Next, the urethane (meth) acrylate (A2) obtained by reacting the polyester polyol (a4) having an aromatic ring in the molecular structure with the (meth) acrylate compound (a5) having an isocyanate group in the molecular structure. explain.

  The polyester polyol (a4) having an aromatic ring in the molecular structure used as the raw material for the urethane (meth) acrylate (A2) is the same as the polyester polyol (a1) exemplified as the raw material for the urethane (meth) acrylate (A1). One can be used alone, or two or more can be used in combination.

  Examples of the (meth) acrylate compound (a5) having an isocyanate group in the molecular structure used as a raw material of the urethane (meth) acrylate (A2) include a compound represented by the following general formula 1, and one isocyanate group and one Monomer having (meth) acryloyl group, monomer having one isocyanate group and two (meth) acryloyl groups, monomer having one isocyanate group and three (meth) acryloyl groups, one isocyanate And a monomer having a group and four (meth) acryloyl groups, a monomer having one isocyanate group and five (meth) acryloyl groups, and the like.

In general formula (1), R ₁ is a hydrogen atom or a methyl group. R ₂ is an alkylene group having 2 to 4 carbon atoms. n represents an integer of 1 to 5.

  Specific examples of the compound (w) having the isocyanate group and the (meth) acryloyl group include 2-acryloyloxyethyl isocyanate (trade name: “Karenz AOI” manufactured by Showa Denko KK), 2- And methacryloyloxyethyl isocyanate (trade name: “Karenz MOI” manufactured by Showa Denko KK) and 1,1-bis (acryloyloxymethyl) ethyl isocyanate (trade name: “Karenz BEI” manufactured by Showa Denko KK) .

  The urethane (meth) acrylate (A) used in the present invention has a hydroxyl group in the molecular structure. As described above, in addition to the (meth) acryloyl group which is an active energy ray curing system, by having a thermosetting system of the hydroxyl group and the isocyanate group of the polyisocyanate compound (B), a very high adhesive force can be obtained. Can be obtained. Especially, since the resin composition which is more excellent in adhesiveness is obtained, the urethane (meth) acrylate (A) preferably has a hydroxyl value in the range of 5 to 50 mgKOH / g, and in the range of 10 to 35 mgKOH /. Those are more preferred.

  The weight average molecular weight (Mw) of the urethane (meth) acrylate (A) is in the range of 5,000 to 50,000, so that the resin composition has high adhesiveness and viscosity suitable for coating. It becomes a thing. When the weight average molecular weight (Mw) is less than 5,000, the functional group concentration of the acryloyl group becomes too high, so that the cured product becomes hard and brittle, the adhesiveness is lowered, and the viscosity is low and uniformly applied. It becomes a difficult resin composition. On the other hand, when it exceeds 50,000, since the functional group concentration of the acryloyl group is lowered, the adhesiveness is lowered and the resin composition has a high viscosity and is difficult to apply. Among them, since a resin composition having higher adhesion and viscosity suitable for coating is obtained, the weight average molecular weight (Mw) is preferably in the range of 10,000 to 45,000, A range of 000 to 40,000 is particularly preferable.

  In addition, the urethane (meth) acrylate (A) exhibits the effect of improving the adhesion to the base material due to the low molecular weight component and the effect of increasing the strength of the cured product due to the high molecular weight component. Therefore, it is preferable that the molecular weight distribution (Mw / Mn) is relatively large. Specifically, the molecular weight distribution is preferably in the range of 2 to 20, and more preferably in the range of 5 to 15.

  The urethane (meth) acrylate (A) used in the present invention further has a branched structure in the molecular structure, but has higher hydrophobicity, hardly swells even under wet heat conditions, and maintains high adhesiveness. It is preferable because it is possible. The urethane (meth) acrylate (A) having a branched structure in such a molecular structure is obtained, for example, by a method using a trifunctional or higher functional compound as the polyester polyol (a1) or the polyisocyanate compound (a2). Examples thereof include urethane (meth) acrylate (A1) and urethane (meth) acrylate (A2) obtained by a method using a tri- or higher functional polyester polyol (a4). Among them, a urethane (meth) acrylate (A1) obtained by using a tri- or higher functional polyester polyol as the polyester polyol (a1) or a resin assembly which is superior in moisture and heat resistance is obtained and is easy to manufacture. The urethane (meth) acrylate (A2) obtained by using a tri- or higher functional polyol as the polyester polyol (a4) is preferable, and the tri- or higher trifunctional polyol is used as the polyester polyol (a1) from the viewpoint of easy availability of raw materials. Urethane (meth) acrylate (A1) obtained by using polyester polyol is more preferable. At this time, since the polyisocyanate compound (a2) has excellent adhesion to various films and a resin composition capable of maintaining high adhesion even under wet heat conditions is obtained, the aliphatic diisocyanate or the alicyclic diisocyanate is obtained. Preferably, the alicyclic diisocyanate is more preferable.

  The curable composition of the present invention contains a polyisocyanate compound (B) in addition to the urethane (meth) acrylate (A). As described above, in addition to the active energy ray-curable (meth) acryloyl group of the urethane (meth) acrylate (A), the hydroxyl group and polyisocyanate compound (B) of the urethane (meth) acrylate (A) By having a thermosetting system with the isocyanate group it has, a very high adhesive force can be obtained.

  Examples of the polyisocyanate compound (B) used in the present invention include various diisocyanate compounds and tri- or higher functional polyisocyanate compounds. Specifically, the raw material polyisocyanate compound of the urethane (meth) acrylate (A). The various polyisocyanate compounds illustrated as (a2) are mentioned. These may be used alone or in combination of two or more.

  Among these polyisocyanate compounds (B), an aliphatic diisocyanate compound, an alicyclic diisocyanate compound, which is excellent in adhesiveness with various films and can obtain a curable composition capable of maintaining high adhesiveness even under wet heat conditions, Alternatively, a tri- or higher functional polyisocyanate compound obtained using aliphatic diisocyanate or alicyclic diisocyanate as a raw material is preferable, and a nurate type polyisocyanate compound using an aliphatic diisocyanate compound as a raw material is more preferable.

  Moreover, when using a polyisocyanate compound more than trifunctional as a polyisocyanate compound (B), it is preferable that the isocyanate group content is the range of 7-25 mass%.

  The curable composition of this invention contains the radical polymerization initiator (C) for polymerizing the (meth) acryloyl group which the said urethane (meth) acrylate (A) has. Examples of the radical polymerizable initiator (C) include benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4,4′-bisdimethylaminobenzophenone, 4,4′-bisdiethylaminobenzophenone, 4,4′-dichloro. Various benzophenones such as benzophenone, Michler's ketone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone;

Xanthone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone and other xanthones, thioxanthone; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and various acyloin ethers;

Α-diketones such as benzyl and diacetyl; sulfides such as tetramethylthiuram disulfide and p-tolyl disulfide; various benzoic acids such as 4-dimethylaminobenzoic acid and ethyl 4-dimethylaminobenzoate;

3,3′-carbonyl-bis (7-diethylamino) coumarin, 1-hydroxycyclohexyl phenyl ketone, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- [4 -(Methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-hydroxy-2-methyl-1- Phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 1- [4- (2-hydroxyethoxy) phenyl] -2- Hydroxy-2-methyl-1-propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2- Tylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4-benzoyl-4'-methyldimethylsulfide, 2,2'-diethoxyacetophenone, benzyldimethyl Ketal, benzyl-β-methoxyethyl acetal, methyl o-benzoylbenzoate, bis (4-dimethylaminophenyl) ketone, p-dimethylaminoacetophenone, α, α-dichloro-4-phenoxyacetophenone, pentyl-4- Dimethylaminobenzoate, 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer, 2,4-bis-trichloromethyl-6- [di- (ethoxycarbonylmethyl) amino] phenyl-S-triazine, 2 , 4-Bis-trichloromethyl-6- (4-ethoxy Phenyl-S-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-ethoxy) phenyl-S-triazineanthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, etc. Is mentioned. These may be used alone or in combination of two or more.

  Among these, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl- 1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6 -Trimethylbenzoyl) phenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane Use one or more mixed systems selected from the group of -1-one. More and more active against a broad range of wavelengths of light, preferable because of improving the curability.

  Commercially available products of these radical polymerization initiators (C) include, for example, “Irgacure-184”, “Irgacure-149”, “Irgacure-261”, “Irgacure-369”, “Irgacure-500”, and “Irgacure-500”. “Irgacure-651”, “Irgacure-754”, “Irgacure-784”, “Irgacure-819”, “Irgacure-907”, “Irgacure-1116”, “Irgacure-1664”, “Irgacure-1700”, “Irgacure-” 1800 "," Irgacure-1850 "," Irgacure-2959 "," Irgacure-4043 "," Darocur-1173 "," Lucirin TPO "; Nippon Kayaku Co., Ltd." Kayacure-DETX "," Kayacure-MBP ", “Kayacure-DMBI”, "Kayacure-EPA", "Kayacure-OA"; Stowa Chemical's "Bicure-10", "Bicure-55"; Akzo's "Trigonal P1"; Sands' "Sandrei 1000"; Apjon's "Deep" And “QuantaCure-PDO”, “QuantaCure-ITX”, “QuantaCure-EPD”, etc., manufactured by Ward Brenkinsopp.

  When the curable composition of the present invention comprises the urethane (meth) acrylate (A), the polyisocyanate compound (B), and the radical polymerization initiator (C), the urethane (meth) ) The blending ratio of the acrylate (A) and the polyisocyanate compound (B) is high in curability when irradiated with active energy rays and has excellent adhesion to various types of films, even under wet heat conditions. Since the curable composition can maintain high adhesiveness, the polyisocyanate compound (B) is in a range of 1 to 20 parts by mass with respect to 100 parts by mass of the urethane (meth) acrylate (A). The ratio is preferably in the range of 5 to 10 parts by mass.

  The blending amount of the radical polymerization initiator is preferably an amount capable of sufficiently exhibiting the function as an initiator, and is preferably within a range in which no precipitation of crystals or deterioration of physical properties of the coating film occurs. Is preferably used at a ratio of 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the curable composition.

  The curable composition of the present invention may contain other resin components in addition to the urethane (meth) acrylate (A), the polyisocyanate compound (B), and the radical polymerization initiator (C).

  Other resin components include, for example, various (meth) acryloyl group-containing monomers, (meth) acryloyl group-containing compounds other than the urethane (meth) acrylate such as epoxy (meth) acrylate, polyester resins, acrylic resins, An epoxy resin, a polycarbonate resin, etc. are mentioned. Especially, since it becomes a resin composition with higher adhesiveness, a polyester resin (D), an epoxy resin (E), and a polycarbonate resin (F) are preferable.

  Since the resin composition of this invention turns into a resin composition which is excellent by the adhesiveness in wet heat conditions, it is preferable to contain the said polyester resin (D). Examples of the polyester resin (D) include those obtained by reacting a polyol and a polybasic acid as essential components.

  Examples of the polyol used as the raw material for the polyester resin (D) include various diols and trifunctional or higher functional polyols exemplified as the raw material for the polyester polyol constituting the urethane (meth) acrylate (A1). These may be used alone or in combination of two or more. Of these, aliphatic diols or trifunctional or higher aliphatic polyols are preferred because they provide a resin composition that has excellent adhesion to various types of films and can maintain high adhesion even under wet heat conditions.

  The polybasic acid used as the raw material of the polyester resin (D) is, for example, various dibasic acids and trifunctional or higher polybasic acids exemplified as the raw material of the polyester polyol constituting the urethane (meth) acrylate (A1). Can be mentioned. These may be used alone or in combination of two or more. Among these, an aliphatic dibasic acid or a trifunctional or higher functional polybasic acid is preferable because a resin composition that has excellent adhesion to various films and can maintain high adhesion even under wet heat conditions. Further, when a highly versatile polyethylene terephthalate film is used as the plastic film, a higher adhesive force can be obtained by using an aromatic dibasic acid or a trifunctional or higher functional polybasic acid.

  The polyester resin (D) is obtained, for example, by reacting these polyols and polybasic acids in a temperature range of 140 to 270 ° C.

  The polyester resin (D) used in the present invention may be a polyester polyurethane resin obtained by further reacting a polyester polyol obtained by reacting a polyol and a polybasic acid with a polyisocyanate compound.

  The weight average molecular weight (Mw) of the polyester resin (D) thus obtained is excellent in adhesion to various films, and a resin composition that can maintain high adhesion even under wet heat conditions is obtained. The range is preferably from 000 to 50,000, and more preferably from 10,000 to 30,000.

  Furthermore, the molecular weight distribution (Mw / Mn) of the polyester resin (D) has the effect of improving the adhesion to the substrate due to the low molecular weight component and the effect of increasing the strength of the cured product due to the high molecular weight component. Is preferably in the range of 2-20, more preferably in the range of 5-15.

  Moreover, it is preferable that the said polyester resin (D) has a hydroxyl group used as the reactive site with the said polyisocyanate compound (B), and since the hydroxyl value becomes a resin composition with higher adhesiveness, it is 5-5. The range is preferably 25 mg KOH / g.

  When the resin composition of the present invention contains the polyester resin (D), the blending amount thereof is high in curability when irradiated with active energy rays and has excellent adhesion to various types of films under wet heat conditions. The mass ratio [(A) / (D)] of the urethane (meth) acrylate (A) and the polyester resin (D) is 1 / The ratio is preferably in the range of 2 to 2/1, and more preferably in the ratio of 1 / 1.2 to 1 / 0.8.

  Moreover, when the resin composition of this invention contains the said polyester resin (D), the compounding quantity of the said polyisocyanate compound (B) has high curability at the time of active energy ray irradiation, and various kinds of films Since it becomes a resin composition which is excellent in adhesiveness to water and can maintain high adhesiveness even under wet heat conditions, with respect to a total of 100 parts by mass of the urethane (meth) acrylate (A) and the polyester resin (D) The ratio is preferably in the range of 1 to 15 parts by mass, and more preferably in the range of 3 to 10 parts by mass.

  Since the resin composition of the present invention can exhibit high adhesiveness to a film made of a fluororesin such as a polyvinyl fluoride resin or a polyvinylidene fluoride resin having generally low adhesiveness, the epoxy resin (E) It is preferable to contain.

  The epoxy resin (E) preferably has a hydroxyl group in the molecular structure as a reaction point with the isocyanate compound (B), and the hydroxyl value is preferably in the range of 30 to 160 mgKOH. A range of 50 to 150 mgKOH / g is more preferable.

  Further, the number average molecular weight (Mn) of the epoxy resin (E) is excellent in solubility in the urethane (meth) acrylate (A) and the polyester resin (D), and is difficult for the fluorine-based substrate and the like. Since it is excellent in the adhesiveness with respect to an adhesive film, it is preferable that it is the range of 500-5,000, and it is more preferable that it is the range of 100-2,000.

  Such an epoxy resin (E) is, for example, a bisphenol type epoxy resin such as a bisphenol A type epoxy resin or a bisphenol F type epoxy resin; a biphenyl type epoxy resin such as a biphenyl type epoxy resin or a tetramethylbiphenyl type epoxy resin; Examples include pentadiene-phenol addition reaction type epoxy resins. These may be used alone or in combination of two or more. Among these, bisphenol-type epoxy resins are preferable because they are more excellent in adhesion to difficult-to-adhere films such as the fluorine-based substrate.

  When the resin composition of the present invention contains the epoxy resin (E), the blending amount thereof is high in curability during irradiation with active energy rays and has excellent adhesion to various types of films under wet heat conditions. Even if it becomes a resin composition which can maintain high adhesiveness, the range of 5 to 25 parts by mass with respect to a total of 100 parts by mass of the urethane (meth) acrylate (A) and the polyester resin (D). It is preferable that it is the ratio used as this, and it is more preferable that it is a ratio used as the range of 8-20 mass parts.

  Since the resin composition of this invention turns into a resin composition which is excellent by the adhesiveness on wet-heat conditions, it is preferable to contain the said polycarbonate resin (F).

  The polycarbonate resin (F) preferably has a hydroxyl group in the molecular structure as a reaction point with the isocyanate compound (B), and the hydroxyl value is preferably in the range of 20 to 300 mgKOH. More preferably, it is in the range of 40 to 250 mgKOH / g.

  In addition, the number average molecular weight (Mn) of the polycarbonate resin (F) is excellent in solubility in the urethane (meth) acrylate (A) and the polyester resin (D), and is adhesive due to wet heat conditions. Since it becomes the resin composition which is excellent, it is preferable that it is the range of 500-5,000, and it is more preferable that it is the range of 800-2,200.

  Examples of the hydroxyl group-containing polycarbonate resin (F) include those produced by a polycondensation reaction of a polyhydric alcohol and a carbonylating agent.

  Examples of the polyhydric alcohol used in the production of the hydroxyl group-containing polycarbonate resin (F) include various diols exemplified as a raw material of the polyester polyol constituting the urethane (meth) acrylate (A1) and a trifunctional or higher functional polyol. These may be used alone or in combination of two or more.

  Examples of the carbonylating agent used in the production of the hydroxyl group-containing polycarbonate resin (F) include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate and the like. These may be used alone or in combination of two or more.

  When the resin composition of the present invention contains the polycarbonate resin (F), the blending amount thereof is high in curability during irradiation with active energy rays and has excellent adhesion to various types of films under wet heat conditions. Even if it becomes a resin composition which can maintain high adhesiveness, the range of 5 to 25 parts by mass with respect to a total of 100 parts by mass of the urethane (meth) acrylate (A) and the polyester resin (D). It is preferable that it is the ratio used as this, and it is more preferable that it is a ratio used as the range of 8-20 mass parts.

  The resin composition of the present invention may further contain various solvents. Examples of the solvent include ketone compounds such as acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone, cyclic ether compounds such as tetrahydrofuran (THF) and dioxolane, and ester compounds such as methyl acetate, ethyl acetate and butyl acetate. Aromatic compounds such as toluene and xylene, and alcohol compounds such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether. These may be used alone or in combination of two or more.

  The resin composition of the present invention further contains various additives such as an ultraviolet absorber, an antioxidant, a silicon-based additive, a fluorine-based additive, a rheology control agent, a defoaming agent, an antistatic agent, and an antifogging agent. You may do it.

  The resin composition of the present invention can be suitably used as an adhesive for bonding various films.

  Examples of the various films include polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine resin, triacetyl cellulose resin, polyvinyl alcohol, ABS resin, norbornene resin, cyclic olefin resin, and polyimide. Examples thereof include a plastic film made of a resin, a polyvinyl fluoride resin, a polyvinylidene fluoride resin, and a metal foil. The adhesive of the present invention exhibits high adhesion even to films made of polyvinyl fluoride resin or polyvinylidene fluoride resin, which are particularly difficult to bond among the various films.

When adhering the various films, the amount of the adhesive of the present invention is preferably in the range of ² to 10 g / m ² .

  A laminated film obtained by adhering a plurality of films using the adhesive of the present invention has high adhesiveness even under wet heat conditions, and has a characteristic that the films are difficult to peel off. Therefore, the adhesive of the present invention can be suitably used for laminated film applications used in harsh environments such as outdoors. Examples of such applications include adhesives for manufacturing back sheets for solar cells. Is mentioned.

  Hereinafter, the present invention will be described in more detail with reference to specific synthesis examples and examples, but the present invention is not limited to these examples.

  In Examples of the present application, the number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

Production Example 1
Manufacture of urethane (meth) acrylate (A-1) solution In a flask having a stirrer, a temperature sensor, and a rectifying tube, 446 parts by mass of neopentyl glycol, 319 parts by mass of isophthalic acid, 142 parts by mass of phthalic anhydride, 194 sebacic acid 194 An organic titanium compound 0.5 mass part was prepared as a mass part and an esterification catalyst, and dry nitrogen was flowed in the flask, and it heated at 230-250 degreeC, stirring, and performed esterification reaction. When the acid value became 1.0 mgKOH / g or less, the reaction was stopped to obtain a polyester polyol intermediate (1). The number average molecular weight (Mn) of the intermediate was 3,500, and the hydroxyl value was 31 mgKOH / g. Next, the flask for producing the polyester polyol intermediate (1) was reheated to 100 ° C., and 176 parts by mass of normal butyl acetate, 39 parts by mass of 2-acryloyloxyethyl isocyanate, and 0.3 part by mass of hydroquinone monomethyl ether were added. Then, dry air was allowed to flow into the flask and heated to 70 to 80 ° C. with stirring to conduct a urethanization reaction. The reaction was stopped when the isocyanate content became 0.3% by mass or less, and diluted with ethyl acetate until the solid content became 60% by mass to obtain a urethane (meth) acrylate (A-1) solution. . The resulting urethane (meth) acrylate (A-1) has a weight average molecular weight (Mw) of 9,900, a number average molecular weight (Mn) of 3,600, a molecular weight distribution (Mw / Mn) of 2.8, and a hydroxyl value. The solid content was 15 mg KOH / g, and the aromatic ring content was 2.91 mmol / g.

Production Example 2
Production of urethane (meth) acrylate (A-2) solution In a flask having a stirrer, a temperature sensor and a rectifying tube, 350 parts by mass of neopentyl glycol, 56 parts by mass of trimethylolpropane, 268 parts by mass of isophthalic acid, phthalic anhydride 119 parts by mass, 163 parts by mass of sebacic acid, and 0.4 parts by mass of an organic titanium compound as an esterification catalyst were added, and the esterification reaction was carried out by heating to 230-250 ° C. while allowing dry air to flow in the flask . The reaction was stopped when the acid value became 1.0 mgKOH / g or less to obtain a polyester polyol intermediate (2). The number average molecular weight (Mn) of the intermediate was 2,700, and the hydroxyl value was 60 mgKOH / g. Next, the flask for producing the polyester polyol intermediate (2) was reheated to 100 ° C., 176 parts by weight of normal butyl acetate, 50 parts by weight of 2-hydroxyethyl acrylate, 0.3 part by weight of hydroquinone monomethyl ether, tin octoate 0.2 parts by mass and 110 parts by mass of dicyclohexylmethane-4,4′-diisocyanate were added, and dry air was allowed to flow into the flask and heated to 70 to 80 ° C. with stirring to conduct a urethanization reaction. The reaction was stopped when the isocyanate content became 0.3% by mass or less, and diluted with ethyl acetate until the solid content became 60% by mass to obtain a urethane (meth) acrylate (A-2) solution. . The resulting urethane (meth) acrylate (A-2) has a weight average molecular weight (Mw) of 30,000, a number average molecular weight (Mn) of 2,800, a molecular weight distribution (Mw / Mn) of 10.7, and a hydroxyl value. The solid content was 27 mg KOH / g, and the aromatic ring content was 2.45 mmol / g.

Production Example 3
Production of polyester resin (D-1) solution In a flask having a stirrer, a temperature sensor, and a rectifying tube, 464 parts by mass of neopentyl glycol, 329 parts by mass of isophthalic acid, 154 parts by mass of phthalic anhydride, trimellitic anhydride 8. 5 parts by mass, 228 parts by mass of sebacic acid, and 0.6 parts by mass of an organic titanium compound as an esterification catalyst were charged, and dry nitrogen was flowed into the flask and heated to 230 to 250 ° C. while stirring to conduct an esterification reaction. . The reaction was stopped when the acid value became 1.0 mgKOH / g or less, and diluted with ethyl acetate until the solid content became 62% by mass to obtain a polyester resin (D-1) solution. The obtained polyester resin (D-1) has a weight average molecular weight (Mw) of 25,000, a number average molecular weight (Mn) of 4,800, a molecular weight distribution (Mw / Mn) of 5.2, and a hydroxyl value of solid content. It was 10 mgKOH / g in terms of conversion.

Comparative production example 1
Production of urethane (meth) acrylate (a-1) In a flask having a stirrer, a temperature sensor, and a rectifying tube, 603 parts by mass of 3-methyl-1,5-pentanediol, 562 parts by mass of adipic acid, and an esterification catalyst As an organic titanium compound, 0.5 part by mass was charged, and dry nitrogen was allowed to flow into the flask. The reaction was stopped when the acid value became 1.0 mgKOH / g or less to obtain a polyester polyol intermediate (1 ′). The number average molecular weight (Mn) of the intermediate was 6,800, and the hydroxyl value was 16.5 mgKOH / g. Next, the flask for producing the polyester polyol intermediate (1 ′) was reheated to 100 ° C., 16 parts by mass of 2-hydroxyethyl acrylate, 0.3 parts by mass of hydroquinone monomethyl ether, 0.3 parts by mass of tin octoate, Then, 31 parts by mass of isophorone diisocyanate was added, and dry oxygen was allowed to flow into the flask and heated to 70 to 80 ° C. while stirring to conduct a urethanization reaction. The reaction was stopped when the isocyanate content became 0.3% by mass or less, and diluted with ethyl acetate until the solid content became 60% by mass to obtain a urethane (meth) acrylate (a-1) solution. . The resulting urethane (meth) acrylate (a-1) has a weight average molecular weight (Mw) of 30,000, a number average molecular weight (Mn) of 7,200, a molecular weight distribution (Mw / Mn) of 4.2, and a hydroxyl value. The solid content was 7.9 mgKOH / g.

Comparative production example 2
Manufacture of urethane (meth) acrylate (a-2) In a flask having a stirring bar, a temperature sensor, and a rectifying tube, 872.2 parts by mass of methyl ethyl ketone, polyester diol (“P-3010” number average molecular weight 3,000 manufactured by Kuraray Co., Ltd.) ) 815.8 parts by mass, cyclohexanedimethanol 39.2 parts by mass, and 17.2 parts by mass of an acrylic acid adduct of propylene glycol diglycidyl ether (“Epoxyester 70PA” manufactured by Kyoeisha Chemical Co., Ltd.) After warming, 0.5 parts by weight of dibutyltin dilaurate was added. Next, a mixed solution of 127.8 parts by mass of isophorone diisocyanate and 127.8 parts by mass of methyl ethyl ketone was dropped over 2 hours. One hour after the completion of dropping, 0.05 part by weight of dibutyltin dilaurate was added, the reaction was stopped when the isocyanate content was 0.3% by weight or less, and the solution was diluted with methyl ethyl ketone until the solid content became 40% by weight. A urethane (meth) acrylate (a-2) solution was obtained. The resulting urethane (meth) acrylate (a-2) has a weight average molecular weight (Mw) of 90,000, a number average molecular weight (Mn) of 47,000, a molecular weight distribution (Mw / Mn) of 1.9, and a hydroxyl value. Was 7.6 mgKOH / g in terms of solid content.

In addition, each compound used in the examples and comparative examples of the present invention is as follows.
Polyisocyanate compound (B)
Polyisocyanate (B-1): Nurate polyisocyanate of hexamethylene diisocyanate (“Bernock DN-902S” manufactured by DIC Corporation)

Radical polymerization initiator (C)
Radical polymerization initiator (C-1) 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure-2959” manufactured by BASF) )

Epoxy resin (E)
Epoxy resin (E-1): bisphenol A type epoxy resin having a number average molecular weight (Mn) of 470, an epoxy equivalent of 245 g / eq, and a hydroxyl value of 96 mgKOH / g (“Epiclon 860” manufactured by DIC Corporation)

  The hydroxyl value of the epoxy resin (E) is determined by measuring the abundance ratio of epoxy resins having different degrees of polymerization present in the epoxy resin (E) by GPC. It is a value calculated from the value with the theoretical hydroxyl value.

Polycarbonate resin (F)
Polycarbonate resin (F-1): polycarbonate diol having a number average molecular weight (Mn) of 1,000 and a hydroxyl value of 110 mgKOH / g (“Placcel CD210” manufactured by Daicel Chemical Industries)

Reference example 1
Production of Resin Composition (1) 66 parts by mass of urethane (meth) acrylate (A1-1) solution obtained in Production Example 1 [39.6 parts by mass of urethane (meth) acrylate (A1-1) in 66 parts by mass ] 1 part by mass of the polyisocyanate compound (B-1) obtained in Production Example 3 and 2 parts by mass of the radical polymerization initiator (C-1) were mixed to obtain a resin composition (1).

Creation of laminated film Using a 125 μm-thick PET film (“X10S” manufactured by Toray Industries, Inc.) as a base material, the resin composition (1) has a mass of solid content after solvent drying of 5 to 6 g / m ² . Then, a 25 μm-thick fluorine film (“Aflex 25PW” manufactured by Asahi Glass Co., Ltd.) was bonded. This was dried in a drier at 70 ° C. for 1 minute, and then irradiated with 100 mJ / cm ² of ultraviolet rays using a high-pressure mercury lamp. Furthermore, it left still on 25 degreeC and humidity 50% RH conditions for 1 day, and obtained the laminated | multilayer film (1).

Evaluation The performance of the obtained laminated film (1) was evaluated by the following various tests, and the results are shown in Table 1.

Evaluation 1: Measurement of initial adhesive strength For the laminated film (1), using a tensile tester (“AGS500NG” manufactured by SHIMADZU), 25 ° C., humidity 50% RH, peeling speed speed 300 mm / min, N / 15 mm A T-type peel test was performed under the conditions, and the strength was measured.

Evaluation 2: Measurement of adhesive strength under wet heat conditions After the laminated film (1) was exposed to a temperature of 121 ° C. and a humidity of 100% RH for 25 hours, 50 hours, and 75 hours, a tensile tester ( A T-type peel test was performed under the conditions of 25 ° C., humidity 50% RH, peel speed speed 300 mm / min, N / 15 mm using SHIMADZU “AGS500NG”, and the strength was measured.

Evaluation 3: Measurement of adhesive strength under high temperature conditions For the laminated film (1), using a tensile tester (“AGS500NG” manufactured by SHIMADZU), 80 ° C., humidity 50% RH, peeling speed 300 mm / min, N A T-type peel test was performed under the condition of / 15 mm, and the strength was measured.

Reference Example 2 Examples 1 and 2
Evaluation was performed in the same manner as in Reference Example 1 except that the composition of the resin composition was changed as shown in Table 1. The evaluation results are shown in Table 1.

Example 3
The composition of the resin composition was changed as shown in Table 1 and evaluated in the same manner as in Reference Example 1 except that the temperature at the time of standing for 1 day in the production process of the laminated film was changed from 25 ° C. to 50 ° C. . The evaluation results are shown in Table 1.

Comparative Examples 1 and 2
An evaluation sample was prepared and evaluated in the same manner as in Example 1 except that the composition of the resin composition was changed as shown in Table 2. The evaluation results are shown in Table 2.

Claims (13)

Urethane (meth) acrylate (A), polyisocyanate compound (B) having an aromatic ring-containing polyester skeleton and a hydroxyl group in the molecular structure, and an aromatic ring content in the range of 1.0 to 4.0 mmol / g , Radical polymerization initiator (C) , and polyester resin (D) having a weight average molecular weight (Mw) in the range of 5,000 to 50,000 and a hydroxyl value in the range of 5 to 25 mgKOH / g A curable composition comprising: The urethane (meth) acrylate (A) reacts with the polyester polyol (a1) having an aromatic ring in the molecular structure, the polyisocyanate compound (a2), and the (meth) acrylate compound (a3) having a hydroxyl group in the molecular structure. The curable composition according to claim 1, wherein the curable composition is obtained. The curable composition according to claim 2, wherein the polyester polyol (a1) having an aromatic ring in the molecular structure contains an aromatic ring structure in the molecular structure in a range of 1.5 to 4.5 mmol / g. . The curable composition according to claim 1, wherein the urethane (meth) acrylate (A) has a branched structure in the molecular structure. The curable composition according to claim 1, wherein the urethane (meth) acrylate (A) has a weight average molecular weight (Mw) in the range of 5,000 to 50,000. The curable composition according to claim 1, wherein the urethane (meth) acrylate (A) has a hydroxyl value in the range of 5 to 50 mgKOH / g. The curable composition of Claim 1 which contains the said polyisocyanate compound (B) in the ratio used as the range of 1-20 mass parts with respect to 100 mass parts of said urethane (meth) acrylates (A). The urethane (meth) acrylate (A) and the mass ratio of the polyester resin (D) [(A) / (D)] is curable composition of claim 1 placing in the range of 1/2 to 2/1 . Along with the urethane (meth) acrylate (A), the polyisocyanate compound (B), the radical polymerization initiator (C), and the polyester resin (D), a bisphenol-type epoxy resin (E) and a polycarbonate resin (F The curable composition according to claim 1, comprising: Containing 100 parts by mass of the urethane (meth) acrylate (A) and the polyester resin (D), the bisphenol-type epoxy resin (E) is contained at a ratio of 5 to 25 parts by mass, and the polycarbonate resin The curable composition of Claim 9 which contains (F) in the ratio used as the range of 5-25 mass parts. Adhesive containing curable composition according to any one of claims 1 to 1 0. The laminated film which has 1 or more types of films chosen from the group which consists of a polyester film, a fluorine film, a polyolefin film, and metal foil, and the contact bonding layer which consists of an adhesive agent of Claim 11 . The backsheet of a solar cell having an adhesive layer comprising an adhesive agent according to claim 1 1, wherein.