JP2010138299A - Curable resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition capable of forming coating film of slight curl and high weatherability, excellent in moist-heat adhesivity to a substrate and storage stability, and suitably usable in solar cell backing sheets or the like by coating a substrate therewith. <P>SOLUTION: The curable resin composition includes: a curing agent, colorant and an ultraviolet-absorbing copolymer which is obtained by polymerization of a monomer mixture comprising an ultraviolet-absorbing monomer and an ultraviolet-stable monomer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a curable resin composition. More specifically, for example, the present invention relates to a curable resin composition that can be suitably used for a solar battery backsheet and the like.

  In general, when the resin base material is irradiated with ultraviolet rays contained in sunlight or the like, the main chain of the resin is broken, so that the mechanical strength of the resin base material is lowered. Therefore, in order to protect the resin substrate from ultraviolet rays, an ultraviolet-absorbing composite film in which an ultraviolet-absorbing copolymer layer is formed on the treated surface of the resin substrate that has been subjected to an easy adhesion treatment has been proposed. (For example, refer to Patent Document 1). However, this ultraviolet-absorbing composite film is excellent in ultraviolet-absorbing property, adhesion to a resin base material and weather resistance, but requires an easy adhesion treatment.

  A plastic substrate having a surface wetness index of 34 mN / m is used as a resin composition for forming an ultraviolet absorbing layer having excellent adhesion to the surface of the resin substrate without subjecting the substrate to easy adhesion treatment. An ultraviolet-absorbing resin composition that forms an ultraviolet-absorbing layer having a cross-cut adhesion after curing with a material of 95% or more has been proposed (for example, see Patent Document 2). However, it is necessary to confirm a specific surface wetting index when confirming whether this ultraviolet-absorbing resin composition is suitable for a plastic substrate.

In recent years, a curl is small, a film with excellent weather resistance is formed, easy adhesion treatment is performed, and it is excellent in wet heat adhesion with a base material without using a plastic base material having a specific surface wetting index. Therefore, development of a curable resin composition excellent in storage stability is desired.
JP 11-348199 A JP 2008-56859 A

  The present invention has been made in view of the above prior art, and forms a coating film with small curl and excellent weather resistance, and is a curable resin composition excellent in wet heat adhesion with a substrate and storage stability. It is an issue to provide.

  The present invention is characterized by containing a UV-absorbing copolymer obtained by polymerizing a monomer mixture containing a UV-absorbing monomer and a UV-stable monomer, a curing agent, and a colorant. The present invention relates to a curable resin composition.

  The curable resin composition of the present invention has an effect that a curl is small, a coating film excellent in weather resistance is formed, and wet-heat adhesion with a substrate and storage stability are excellent.

  As described above, the curable resin composition of the present invention is a UV-absorbing copolymer obtained by polymerizing a monomer mixture containing a UV-absorbing monomer and a UV-stable monomer, a curing agent, And a colorant.

  Since the curable resin composition of the present invention uses a UV-absorbing monomer and a UV-stable monomer in combination, it forms a coating film with small curl and excellent weather resistance. Excellent wet heat adhesion and storage stability.

The UV-absorbing monomer mainly imparts UV-absorbing property to the curable resin composition of the present invention, and when used in combination with the UV-stable monomer, it has a small curl and excellent weather resistance. It is a component that is formed and improves wet heat adhesion and storage stability with the resin substrate.
Suitable ultraviolet absorbing monomers include, for example, formula (I):

Wherein R ¹ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 12 carbon atoms, R ² is an alkylene group having 1 to 6 carbon atoms, R ³ is a hydrogen atom or a methyl group, X ¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or 7 to 12 carbon atoms. Aralkyl, cyano or nitro)
A monomer represented by formula (II):

(Wherein R ⁴ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 12 carbon atoms, R ⁵ is a hydrogen atom or a methyl group, and R ⁶ is hydrogen. An atom or a hydroxyl group, R ⁷ is a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms, R ⁸ is an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group having 1 to 10 carbon atoms, X ² is an ester bond, an amide bond, Ether bond or urethane bond, m represents 0 or 1)
A monomer represented by formula (III):

[Wherein, R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or 2 to 2 carbon atoms. 10 is an alkenyl group or an alkoxy group having 1 to 10 carbon atoms, Y is a hydrogen atom or a methyl group, A is a — (CH ₂ CH ₂ O) _p — group (p is an integer of 1 to 20), —CH ₂ CH ( OH) —CH ₂ O— group, — (CH ₂ ) _p —O— group (p is the same as above), —CH ₂ CH (CH ₂ OR ¹⁷ ) —O— group (R ¹⁷ has 1 to 10 carbon atoms) Alkyl group), —CH ₂ CH (R ¹⁷ ) —O— group (R ¹⁷ is the same as above) or —CH ₂ (CH ₂ ) _q COO—B—O— group (B is a methylene group, ethylene group or —CH ₂ CH (OH) CH ₂ — group, q represents 0 or 1)]
And a monomer represented by the formula (IV):

Wherein R ¹⁸ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and R ¹⁹ is a group having an element capable of forming a hydrogen bond. R ²⁰ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms)
And the like. These monomers may be used alone or in combination of two or more. These monomers impart UV absorption to the curable resin composition of the present invention, and in combination with UV-stable monomers, there is no need for an easy adhesion treatment, and a specific surface wetting index is obtained. Even if it does not have the plastic base material which has, the coating film excellent in wet heat adhesiveness and a weather resistance with a base material can be formed.

In the monomer represented by the formula (I), R ¹ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, and octyl groups. A chain or branched alkyl group; an alicyclic alkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the aryl group having 6 to 12 carbon atoms, preferably 6 to 8 carbon atoms include a phenyl group and a tolyl group. Examples of the aralkyl group having 7 to 12 carbon atoms, preferably 7 to 8 carbon atoms include a benzyl group and a phenethyl group.

In the monomer represented by the formula (I), R ² represents an alkylene group having 1 to 6 carbon atoms. Examples of the alkylene group having 1 to 6 carbon atoms include linear alkylene groups such as methylene group, ethylene group, propylene group, butylene group, pentylene group, and hexylene group; isopropylene group, isobutylene group, sec-butylene group, and tert. -Branched alkylene groups, such as a butylene group, an isopentylene group, a neopentylene group, etc. are mentioned.

In the monomer represented by the formula (I), R ³ represents a hydrogen atom or a methyl group. X ¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a cyano group or a nitro group Indicates a group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, and octyl groups. Examples include chain or branched alkyl groups; cyclopropyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, and other alicyclic alkyl groups. Examples of the aryl group having 6 to 12 carbon atoms, preferably 6 to 8 carbon atoms include a phenyl group and a tolyl group. Examples of the aralkyl group having 7 to 12 carbon atoms, preferably 7 to 8 carbon atoms, include a benzyl group and a phenethyl group. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group.

  Specific examples of the monomer represented by the formula (I) include 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5. '-(Methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5'-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2 '-Hydroxy-5'-tert-butyl-3'-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-chloro- 2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5 Such as methoxy -2H- benzotriazole. These monomers may be used alone or in combination of two or more.

In the monomer represented by the formula (II), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, and octyl groups. Examples include chain or branched alkyl groups; cyclopropyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, and other alicyclic alkyl groups. Examples of the aryl group having 6 to 12 carbon atoms, preferably 6 to 8 carbon atoms include a phenyl group and a tolyl group. Examples of the aralkyl group having 7 to 12 carbon atoms, preferably 7 to 8 carbon atoms include a benzyl group and a phenethyl group.

In the monomer represented by the formula (II), R ⁵ represents a hydrogen atom or a methyl group. R ⁶ represents a hydrogen atom or a hydroxyl group. R ⁷ represents a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group.

In the monomer represented by the formula (II), R ⁸ represents an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group having 1 to 10 carbon atoms. Examples of the alkylene group having 1 to 10 carbon atoms include linear alkylene groups such as methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group and decylene group; Examples thereof include branched alkylene groups such as a propylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, an isopentylene group, a neopentylene group, and a 2-ethylhexylene group. Examples of the oxyalkylene group having 1 to 10 carbon atoms include an oxymethylene group, an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxypentylene group, an oxyhexylene group, an oxyheptylene group, an oxyoctylene group, and an oxynonylene group. , Linear alkylene groups such as oxydecylene group; oxyisopropylene group, oxyisobutylene group, oxysec-butylene group, oxytert-butylene group, oxyisopentylene group, oxyneopentylene group, oxy-2-ethylhexylene group And branched alkylene groups such as

In the monomer represented by the formula (II), X ² represents an ester bond, an amide bond, an ether bond or a urethane bond. The ester bond specifically means an oxycarbonyl [—O—C (O) —] group and a carbonyloxy [—C (O) —O—] group. An amide bond specifically means a —NH— group. Further, the ether bond specifically means a —O— group. m represents 0 or 1.

  Specific examples of the monomer represented by the formula (II) include 2-hydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [2- (meth) acryloyloxy]. Butoxybenzophenone, 2,2′-dihydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [2- (meth) acryloyloxy] ethoxy-4 ′-(2-hydroxyethoxy) Benzophenone, 2-hydroxy-3-tert-butyl-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-3-tert-butyl-4- [2- (meth) acryloyloxy] butoxybenzophenone, etc. Is mentioned. These monomers may be used alone or in combination of two or more.

In the monomer represented by the formula (III), R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, A 10 alkyl group, a C2-C10 alkenyl group, or a C1-C10 alkoxy group is shown. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an isopentyl group. , 2,2-dimethylpropyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, 1,1,3,3-tetramethylbutyl group, 2-ethylhexyl group, etc. A linear or branched alkyl group having 1 to 10 carbon atoms; an alicyclic alkyl group having 3 to 10 carbon atoms such as a cyclohexyl group; Examples of the alkenyl group having 2 to 10 carbon atoms include vinyl group, allyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 2-pentenyl group, 3-pentenyl group, 4- Hexenyl group, 5-heptenyl group, 4-methyl-3-pentenyl group, 2,4-dimethyl-3-pentenyl group, 6-methyl-5-heptenyl group, 2,6-dimethyl-5-heptenyl group, etc. It is done. Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, and decyloxy group. .

In the monomer represented by the formula (III), Y represents a hydrogen atom or a methyl group. A represents a — (CH ₂ CH ₂ O) _p — group (p is an integer of 1 to 20), —CH ₂ CH (OH) —CH ₂ O— group, — (CH ₂ ) _p —O— group (p Is the same as above, a —CH ₂ CH (CH ₂ OR ¹⁷ ) —O— group (R ¹⁷ is an alkyl group having 1 to 10 carbon atoms), a —CH ₂ CH (R ¹⁷ ) —O— group (R ¹⁷ is The same as above) or —CH ₂ (CH ₂ ) _q COO—B—O— group (B is a methylene group, ethylene group or —CH ₂ CH (OH) CH ₂ — group, q is 0 or 1). Examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹⁷ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n -Pentyl group, isopentyl group, 2,2-dimethylpropyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, 1,1,3,3-tetramethylbutyl group, 2- C1-C10 linear or branched alkyl groups, such as an ethylhexyl group; C3-C10 alicyclic alkyl groups, such as a cyclohexyl group, etc. are mentioned.

  Examples of the monomer represented by the formula (III) include 2- [2-hydroxy-4- (2-methacryloyloxyethoxy) phenyl] -4,6-diphenyl-1,3,5-triazine, 2 , 4-Diphenyl-6- [2-hydroxy-4- (2-acryloyloxy) phenyl] -1,3,5-triazine, 2,4-bis (2-methylphenyl) -6- [2-hydroxy- 4- (2-acryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bis (2-methoxyphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bis (2-ethylphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) phenyl] -1,3,5-triazine, , 4-bis (2-ethoxyphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-diphenyl-6- [2-hydroxy -4- (2-methacryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bis (2-methylphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyethoxy) phenyl ] -1,3,5-triazine, 2,4-bis (2-methoxyphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyethoxy) phenyl] -1,3,5-triazine, 2 , 4-Bis (2-ethylphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bi (2-Ethoxyphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bis (2,4-dimethoxyphenyl) -6 [2-Hydroxy-4- (2-acryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (2 -Acryloyloxyethoxy) phenyl] -1,3,5-triazine, 2,4-bis (2,4-diethoxyphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) phenyl]- 1,3,5-triazine, 2,4-bis (2,4-diethylphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) phenyl] -1,3,5 -Triazine, 2- [2-hydroxy-4- (11-acryloyloxy-undecyloxy) phenyl] -4,6-diphenyl-1,3,5-triazine, 2- [2-hydroxy-4- (11 -Methacryloyloxy-undecyloxy) phenyl] -4,6-diphenyl-1,3,5-triazine, 2- [2-hydroxy-4- (11-acryloyloxy-undecyloxy) phenyl] -4,6 -Bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (11-methacryloyloxyundecyl) Oxy) phenyl] -1,3,5-triazine, 2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyate) ) Phenyl] -1,3,5-triazines, and the like, the present invention is not limited only to those exemplified. These monomers may be used alone or in combination of two or more.

  Among the monomers represented by the formula (III), since they can be easily obtained industrially, the formula (IIIa):

A monomer represented by formula (IIIb):

And a monomer represented by the formula (IIIc):

The monomer represented by these is preferable. These monomers may be used alone or in combination of two or more.

In the monomer represented by the formula (IV), R ¹⁸ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 8 carbon atoms include carbon such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, and octyl group. C1-C8 alicyclic alkyl groups, such as a C1-C8 linear or branched alkyl group, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. are mentioned. Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

In the monomer represented by the formula (IV), R ¹⁹ represents a group having an element capable of forming a hydrogen bond. Examples of the group having an element that can form a hydrogen bond include a —NH— group, a —CH ₂ NH— group, a —OCH ₂ CH (OH) CH ₂ O— group, a —CH ₂ CH ₂ COOCH ₂ CH (OH ) CH ₂ O— group and the like. Among these groups, an —NH— group and a —CH ₂ NH— group are preferable because of having active hydrogen, and a —CH ₂ NH— group is more preferable.

In the monomer represented by the formula (IV), R ²⁰ represents a hydrogen atom or a methyl group. R ²¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, and nonyl group. , A decyl group, an undecyl group, a dodecyl group, etc., a C1-C12 linear or branched alkyl group, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. An alicyclic alkyl group etc. are mentioned. Among these, a linear or branched alkyl group having 4 to 12 carbon atoms is preferable, and a 1,1,3,3-tetramethylbutyl group is more preferable. R ²¹ is preferably present in the para position with respect to the hydroxyl group at the 2-position from the viewpoint of making it difficult to react with the hydroxyl group at the 2-position.

Examples of the monomer represented by the formula (IV) include 2- [2′-hydroxy-3 ′-(meth) acryloylamino-5 ′-(1,1,3,3-tetramethylbutyl) phenyl. ] -2H-benzotriazole, 2- [2′-hydroxy-3 ′-(meth) acryloylaminomethyl-5 ′-(1,1,3,3-tetramethylbutyl) phenyl] -2H-benzotriazole, 2 -[2'-hydroxy-3 '-(meth) acryloylaminophenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-(meth) acryloylaminomethylphenyl] -2H-benzotriazole, etc. However, the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more. Among these monomers, 2- [2′-hydroxy-3 ′-(meth) acryloylamino-5 ′-(1,1,3,3-tetra] has R ²¹ bonded to the 5-position. Methylbutyl) phenyl] -2H-benzotriazole and 2- [2′-hydroxy-3 ′-(meth) acryloylaminomethyl-5 ′-(1,1,3,3-tetramethylbutyl) phenyl] -2H— Benzotriazole is preferred.

  In the present specification, “(meth) acryl” means “acryl” and / or “methacryl”.

  The monomer represented by the formula (I) and the monomer represented by the formula (IV) include, for example, benzotriazole, (meth) acrylic acid chloride, N-methylolacrylamide, or an alkyl ether thereof. It can be easily prepared by reacting. For example, 2- [2′-hydroxy-3′-methacryloylamino-5 ′-(1,1,3,3-tetramethylbutyl) phenyl] -2H-benzotriazole is 2- [2′-hydroxy-3 It can be prepared by reacting '-amino-5'-(1,1,3,3-tetramethylbutyl) phenyl] -benzotriazole with methacrylic acid chloride. Further, 2- [2′-hydroxy-3′-methacryloylaminomethyl-5 ′-(1,1,3,3-tetramethylbutyl) phenyl] -2H-benzotriazole is 2- [2′-hydroxy- It can be easily prepared by reacting 5 ′-(1,1,3,3-tetramethylbutyl) phenyl] -benzotriazole with N-methylolacrylamide.

  Among the monomers represented by the formulas (I) to (IV), the monomers represented by the formulas (I) to (III) improve wet heat adhesion with the substrate and storage stability. From the viewpoint of improving the curling resistance (the property that the coating film is difficult to curl) and the weather resistance of the coating film. In this case, the monomers represented by the formulas (I) to (III) may be used alone or in combination of two or more.

  The UV-stable monomer imparts a stable UV-absorbing property to the curable resin composition of the present invention, and, in combination with the UV-absorbing monomer, provides a coating film with excellent curl resistance and weather resistance. It is a component that is formed and improves wet heat adhesion and storage stability with the resin substrate.

  Examples of the ultraviolet stable monomer include compounds having a polymerizable double bond and an ultraviolet stable group in the molecule. Suitable UV stable monomers include, for example, formula (V):

(Wherein R ²² is a hydrogen atom or a cyano group, R ²³ and R ²⁴ are each independently a hydrogen atom or a methyl group, R ²⁵ is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, Z is an oxygen atom or an imino group) Group)
And the like.

In the monomer represented by the formula (V), examples of the alkyl group having 1 to 18 carbon atoms represented by R ²⁵ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, Examples include tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. .

  Specific examples of the monomer represented by the formula (V) include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6. , 6-Tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2 , 2,6,6-tetramethylpiperidine and the like, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  The ratio of the UV-absorbing monomer and the UV-stable monomer (UV-absorbing monomer / UV-stable monomer: mass ratio) is from the viewpoint of enhancing the curl resistance and weather resistance of the coating film. Preferably it is 1/1 or more, more preferably 3/1 or more, more preferably 5/1 or more, from the viewpoint of improving the storage stability of the curable resin composition of the present invention while improving the dispersibility of the colorant. , Preferably 100/1 or less, more preferably 50/1 or less, still more preferably 40/1 or less.

  The monomer mixture contains a UV-absorbing monomer and a UV-stable monomer, but increases the cross-linking point with the curing agent in the UV-absorbing copolymer, so that the curable resin composition of the present invention From the viewpoint of improving curability, it is preferable to contain a hydroxyl group-containing monomer.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl. Hydroxyalkyl (meth) acrylate having 1 to 4 carbon atoms of alkyl group such as (meth) acrylate; ε-caprolactone 1 mol adduct of 2-hydroxyethyl (meth) acrylate, ε of 2-hydroxyethyl (meth) acrylate -Ε-caprolactone adduct of hydroxyalkyl (meth) acrylate having 1 to 4 carbon atoms, such as caprolactone 2 mol adduct, ε-caprolactone 3 mol adduct of 2-hydroxyethyl (meth) acrylate, The present invention provides such an example. The present invention is not limited to. These hydroxyl group-containing monomers may be used alone or in combination of two or more.

  The content of the hydroxyl group-containing monomer in the monomer mixture is preferably 3% by mass or more, more preferably 10% by mass from the viewpoint of improving wet heat adhesion with the substrate and enhancing the weather resistance of the coating film. From the viewpoint of improving the curl resistance and weather resistance of the coating film, it is preferably 40% by mass or less, more preferably 20% by mass or less.

  The monomer mixture may contain an appropriate amount of other monomers within the range not impairing the object of the present invention.

  Examples of the other monomer include (meth) acrylate monomers, vinyl ester monomers, silicon atom-containing monomers, halogen atom-containing monomers, nitrogen atom-containing monomers other than those described above. , Polyfunctional monomers, vinyl ether monomers, epoxy group-containing monomers, acidic group-containing monomers, and the like, but the present invention is not limited to such examples.

  Examples of the (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, amyl (meth) acrylate, isoamyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate Tridecyl (meth) acrylate, n-lauryl (meth) acrylate, n-stearyl (meth) acrylate, isostearyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, 2-acetoacetoxyethyl ( Examples thereof include meth) acrylate and phenoxyethyl (meth) acrylate, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Among the (meth) acrylate monomers, methyl (meth) acrylate is preferable, and methyl methacrylate is more preferable from the viewpoint of improving the curl resistance and weather resistance of the coating film and improving wet heat adhesion to the substrate. preferable. The content of methyl (meth) acrylate in the monomer mixture is preferably 20 to 70% by mass from the viewpoint of enhancing the curl resistance and weather resistance of the coating film and improving wet heat adhesion with the substrate.

  Examples of the vinyl ester monomers include vinyl acetate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, and vinyl cyclohexanecarboxylate. , Vinyl pivalate, vinyl octylate, vinyl monochloroacetate, divinyl adipate, vinyl methacrylate, vinyl crotonate, vinyl sorbate, vinyl benzoate, vinyl cinnamate, etc. It is not limited. These monomers may be used alone or in combination of two or more.

  Examples of the silicon atom-containing monomer include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, and trimethylsiloxyethyl. Although (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

  Examples of the halogen atom-containing monomer include trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, and octafluoropentyl (meth). Acrylate, heptadodecafluorodecyl (meth) acrylate, β- (perfluorooctyl) ethyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, ethylene oxide addition (meth) acrylate of tribromophenol, Although tribromophenyl (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

  Examples of the nitrogen atom-containing monomer include (meth) acrylamide, methylenebis (meth) acrylamide, N-methylol (meth) acrylamide, (meth) acryloyloxyethyltrimethylammonium chloride, dimethylaminoethyl (meth) acrylate sulfate. , Ethylene oxide addition (meth) acrylate of morpholine, N-vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrole, N-vinyl pyrrolidone, N-vinyl oxazolidone, N-vinyl succinimide, N-vinyl methyl carbamate, N, Examples include N-methylvinylacetamide and 2-isopropenyl-2-oxazoline, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, Polyethylene glycol-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate 2-hydroxy-1,3-di (meth) acryloxypropane di (meth) acrylate, 2,2-bis [4- (meth) acryloxydiethoxyphenyl] propanedi (meth) acrylate 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane di (meth) acrylate, ethylene oxide modified bisphenol A di (meth) acrylate, propylene oxide modified bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate and the like, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isopropyl ether, vinyl n-propyl ether, vinyl isobutyl ether, vinyl n-butyl ether, vinyl n-amyl ether, vinyl isoamyl ether. , Vinyl-2-ethylhexyl ether, vinyl-n-octadecyl ether, cyanomethyl vinyl ether, 2,2-dimethylaminoethyl vinyl ether, 2-chloroethyl vinyl ether, β-difluoromethyl vinyl ether, benzyl vinyl ether, phenyl vinyl ether, divinyl ether, divinyl Although acetal etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and the like. However, the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the acidic group-containing monomer include sulfoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxypropyl acid phosphate, and the like. It is not limited to illustration only. These monomers may be used alone or in combination of two or more.

  The ultraviolet absorbing copolymer can be prepared by polymerizing the monomer mixture.

  Examples of the method for polymerizing the monomer mixture include a solution polymerization method, a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method, but the present invention is not limited to such a polymerization method. Among these polymerization methods, the solution polymerization method is preferable because the obtained reaction mixture can be used as it is.

  In the following, one embodiment for preparing an ultraviolet absorbing copolymer by polymerizing a monomer mixture by a solution polymerization method will be described, but the present invention is not limited to only that embodiment. .

  Examples of the solvent used when the monomer mixture is polymerized by the solution polymerization method include aromatic solvents such as toluene and xylene; alcohols such as n-butyl alcohol, propylene glycol methyl ether, diacetone alcohol, and ethyl cellosolve. Solvents: ester solvents such as ethyl acetate, butyl acetate and cellosolve acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; dimethylformamide and the like, but the present invention is limited only to such examples is not. The amount of the solvent is preferably determined as appropriate according to the concentration of the monomer mixture, the molecular weight of the target UV-absorbing copolymer, and the like.

  Examples of the polymerization initiator include 2,2′-azobis- (2-methylbutyronitrile), tert-butylperoxy-2-ethylhexanoate, 2,2′-azobisisobutyronitrile, benzoyl Although a peroxide, di-tert-butyl peroxide, etc. are mentioned, this invention is not limited only to this illustration. The amount of the polymerization initiator is usually preferably 0.01 to 30 parts by mass, more preferably 0.05 to 10 parts by mass per 100 parts by mass of the monomer mixture.

  In the polymerization, for example, a chain transfer agent such as n-dodecyl mercaptan may be used in order to adjust the molecular weight of the resulting UV-absorbing copolymer.

  The polymerization temperature for polymerizing the monomer mixture is usually preferably 40 to 200 ° C, more preferably 40 to 140 ° C.

  Since the polymerization time of the monomer mixture varies depending on the polymerization temperature, the composition of the monomer mixture, the type and amount of the polymerization initiator, etc., it cannot be determined unconditionally, and may be appropriately determined according to them. preferable.

  The weight average molecular weight of the UV-absorbing copolymer is preferably 50000 or more, more preferably 60000 or more from the viewpoint of improving wet heat adhesion with the substrate, and the appearance of the coating film and the curable resin composition of the present invention. From the viewpoint of improving the storage stability of the product, it is preferably 500,000 or less, more preferably 300,000 or less, and even more preferably 200000 or less.

  As a hardening | curing agent used for the curable resin composition of this invention, a polyfunctional isocyanate compound, a melamine resin, etc. are mentioned, for example. Among these, a polyfunctional isocyanate compound is preferable from the viewpoint of improving the weather resistance of the coating film. As polyfunctional isocyanate compounds, aromatic polyisocyanates having two or more isocyanate groups, aliphatic polyisocyanates having two or more isocyanate groups, alicyclic polyisocyanates having two or more isocyanate groups, mixtures thereof, Examples thereof include modified polyisocyanates obtained by modification. Of these, aliphatic polyisocyanates and alicyclic polyisocyanates are preferable from the viewpoint of enhancing the weather resistance of the coating film.

  Specific examples of the polyfunctional isocyanate compound include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, polymethylene polyphenylene diisocyanate and other aromatic polyisocyanates, hexamethylene diisocyanate, lysine diisocyanate and other fats. Aliphatic polyisocyanates, hydrogenated methylene diphenyl diisocyanates, hydrogenated tolylene diisocyanates, isophorone diisocyanates and other alicyclic polyisocyanates, mixtures thereof, and modified products thereof. Examples of the modified product include a prepolymer modified product, a nurate modified product, a urea modified product, a carbodiimide modified product, an allophanate modified product, and a burette modified product, which are reaction products with polyol.

  The amount of the curing agent is preferably 0.1 parts by mass or more, more preferably 1 part by mass per 100 parts by mass of the UV-absorbing copolymer, from the viewpoint of improving wet heat adhesion with the substrate and the weather resistance of the coating film. From the viewpoint of enhancing the storage stability of the curable resin composition of the present invention, it is preferably 30 parts by mass or less, more preferably 20 parts by mass or less.

  Moreover, when using a polyfunctional isocyanate compound as a hardening | curing agent, the ratio of an ultraviolet absorptive copolymer and a polyfunctional isocyanate compound is the OH group (hydroxyl group) of the NCO group of a polyfunctional isocyanate compound / the ultraviolet absorptive copolymer ( NCO group / OH group: equivalent ratio) is preferably 0.8 / 1 to 1.2 from the viewpoint of improving the storage stability of the curable resin composition of the present invention and improving the mechanical strength of the coating film. / 1, more preferably 0.9 / 1 to 1.15 / 1, still more preferably 0.95 / 1 to 1.10 / 1.

  Examples of the colorant used in the curable resin composition of the present invention include pigments and dyes, and these may be used alone or in combination. Among these, a pigment is preferable from the viewpoint of improving the weather resistance of the coating film. Examples of the pigment include inorganic pigments and organic pigments, and these may be used alone or in combination. Among the pigments, inorganic pigments are preferable from the viewpoint of enhancing the weather resistance of the coating film. The particle diameter of the pigment is preferably 0.01 μm or more, more preferably 0.1 μm or more from the viewpoint of improving dispersibility, and preferably 1.0 μm or less, more preferably from the viewpoint of forming a smooth coating film. Is 0.5 μm or less.

  Examples of the inorganic pigment include titanium oxide, carbon black, iron oxide, calcium carbonate, mica, aluminum oxide, and chromium oxide. Among these, when the curable resin composition of the present invention is used for the outermost coating film of the solar battery backsheet, titanium oxide is preferable from the viewpoint of improving light reflectivity, and the weather resistance of the coating film is improved. From the viewpoint of enhancing, carbon black is preferable.

  Examples of organic pigments include azo pigments, phthalocyanine pigments, aniline black pigments, and anthraquinone pigments.

  Examples of the dye include natural dyes and chemical dyes. Examples of natural dyes include safflower, saffron, and shellfish purple. These may be used alone or in combination of two or more. Examples of chemical dyes include acid dyes, basic dyes, direct dyes, and reactive dyes. These may be used alone or in combination of two or more. Examples of the acid dye include C.I. I. Acid Black 2, C.I. I. Acid Black 52, C.I. I. Acid Yellow 23, C.I. I. Acid Red 51, C.I. I. Add Red 87 and the like. Examples of basic dyes include C.I. I. Basic Yellow 2, C.I. I. Basic Yellow 11, C.I. I. Basic Red 1, C.I. I. Basic Red 13, C.I. I. Basic Violet 1, C.I. I. Basic Violet 3, C.I. I. Basic Violet 7, C.I. I. Basic Blue 5, C.I. I. Basic Blue 7 etc. are mentioned. Examples of the direct dye include C.I. I. Direct black 19 etc. are mentioned. Examples of reactive dyes include C.I. I. Reactive red 180 and the like.

  Of the colorants, inorganic pigments are preferred. In the case of using an inorganic pigment and a UV-absorbing copolymer obtained by polymerizing a monomer mixture in which a UV-absorbing monomer and a UV-stable monomer are used in combination, As a result, the weather resistance is significantly improved and the wet heat adhesion and curl resistance are improved. Among the inorganic pigments, carbon black and titanium oxide are preferable from the viewpoint of improving the weather resistance and curl resistance of the coating film and improving the wet heat adhesion of the curable resin composition of the present invention.

  The amount of the colorant varies depending on the type of the colorant and the target color concentration, and thus cannot be determined unconditionally. However, it is usually preferable per 100 parts by mass of the UV-absorbing copolymer (resin solid content). Is 0.1 to 300 parts by mass, more preferably 0.3 to 200 parts by mass, and still more preferably 1 to 100 parts by mass.

  The curable resin composition of the present invention may contain, for example, a saturated polyester resin as a resin other than the ultraviolet-absorbing copolymer as long as the object of the present invention is not impaired. Moreover, the curable resin composition of this invention may contain the additive and the organic solvent as needed.

  Examples of additives include organic ultraviolet absorbers such as benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, and indole ultraviolet absorbers, and inorganic ultraviolet absorbers such as zinc oxide. UV absorbers; additive UV stabilizers such as sterically hindered piperidine compounds; flame retardants such as phosphorus compounds, nitrogen compounds, boron compounds and halogen compounds; leveling agents; antioxidants; fillers such as talc; Antifungal agents; dispersion stabilizers; plasticizers; fluorescent whitening agents; surfactants; lithium and organic boron antistatic agents; thickeners; antifoaming agents; inorganic fine particles such as colloidal silica and alumina sol; Examples include acrylic resin fine particles, but the present invention is not limited to such examples. Since the amount of the additive varies depending on the type of the additive and cannot be determined unconditionally, it is preferable to appropriately adjust the amount within the range in which the object of the present invention is not impaired.

  Examples of the organic solvent include aromatic solvents such as toluene and xylene; alcohol solvents such as n-butyl alcohol, propylene glycol methyl ether, diacetone alcohol, and ethyl cellosolve; esters such as butyl acetate, ethyl acetate, and cellosolve acetate Examples of the solvent include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; dimethylformamide and the like, but the present invention is not limited to such examples. Since the amount of the organic solvent varies depending on the use of the curable resin composition of the present invention and cannot be unconditionally determined, the purpose of the present invention depends on the use of the curable resin composition of the present invention. It is preferable to adjust appropriately within a range not hindered.

  The curable resin composition of the present invention can be applied to various substrates. Examples of the material constituting the substrate include polyphenylene sulfide, polyester, polyethylene, polypropylene, triacetyl cellulose, polystyrene, polycarbonate, polyethersulfone, cellophane, polyamide, polyvinyl alcohol, polyacetal, polyphenylene ether, polyimide, polyamideimide, poly Fluorine resin such as etherimide, polyetheretherketone, polytetrafluoroethylene, ABS resin, noryl resin, acrylic resin, epoxy resin, and other inorganic materials such as glass, slate, mortar, iron, copper, aluminum, magnesium However, the present invention is not limited to such examples.

  Among these substrates, the curable resin composition of the present invention can be suitably used for a resin substrate. In particular, it exhibits excellent wet heat adhesion to substrates made of resins such as polyphenylene sulfide and polyester. Examples of the polyester include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. Each of the base materials made of these resins may be composed of a single layer or may have a laminated structure in which a plurality of layers are laminated.

  Since the curable resin composition of the present invention has excellent wet heat adhesion to a substrate made of a resin such as polyphenylene sulfide or polyester, for example, a resin film made of these resins can be used as the substrate. . Among the resin films, a film made of polyester having a number average molecular weight of 18,000 to 40,000 is preferable from the viewpoint of improving wet heat adhesion with the resin film. The thickness of the resin film varies depending on its use and the like, but is preferably 3 to 300 μm, more preferably 5 to 200 μm, for example, when used for a solar battery backsheet. In addition, in order to provide water vapor barrier properties, for example, a metal oxide vapor deposition layer may be formed on the surface of the resin film by vapor deposition of a metal oxide such as aluminum oxide.

  Examples of the method of applying the curable resin composition of the present invention to a substrate include, for example, a spray coating method, a brush coating method, a curtain flow coating method, a gravure coating method, a roll coating method, a spin coating method, a bar coating method, Although the method of immersing a base material in the curable resin composition of this invention including the electrostatic coating method etc. is mentioned, this invention is not limited only to this illustration.

  After coating the curable resin composition of the present invention on a substrate, heating is performed to cure the curable resin composition of the present invention. The heating temperature and heating time vary depending on the composition of the curable resin composition of the present invention and the heat resistant temperature of the substrate, and thus cannot be determined unconditionally, but are usually preferably 80 to 150 ° C., more preferably 90 ~ 120 ° C. The heating time is usually preferably 20 seconds to 3 minutes, more preferably 30 seconds to 2 minutes. After the curable resin composition of the present invention is cured, for example, it is preferable to cure the formed coating film at a temperature of about 30 to 60 ° C. for about 0.5 to 4 days.

  The thickness of the coating film after applying the curable resin composition of the present invention to the surface of the substrate and drying it is preferably 1 μm or more, more preferably from the viewpoint of improving wet heat adhesion with the substrate. The thickness is 3 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less, from the viewpoint of improving wet heat adhesion with the substrate and curling resistance of the coating film.

  As described above, the coating film formed by applying the curable resin composition of the present invention to a resin film made of a resin such as polyphenylene sulfide or polyester is excellent in wet heat adhesion with the substrate, Since it is excellent in the curl resistance and weather resistance of a coating film, it can be used suitably for a solar cell backsheet etc., for example.

  If necessary, the coating film may be laminated with a colored film, a resin film having gas barrier properties, a water vapor blocking resin film, and the like. These resin films can be laminated and integrated via an adhesive if necessary.

  The curable resin composition of the present invention comprises an ultraviolet-absorbing copolymer, a curing agent, and a colorant obtained by polymerizing a monomer mixture containing an ultraviolet-absorbing monomer and an ultraviolet-stable monomer. Therefore, it is excellent in wet heat adhesion with a substrate and storage stability, and a coating film excellent in curling resistance and weather resistance of the coating film can be formed.

  Among these, when the ultraviolet absorbing monomer and the ultraviolet stable monomer in the monomer mixture used as a raw material in the curable resin composition of the present invention are used in the above-described proportions, polyphenylene sulfide, polyester Excellent wet heat adhesion and storage stability with substrates made of resin, etc., improved curl resistance of coating film, makes it less susceptible to humidity, and reduces decrease in tensile strength of coating film over time Thus, there is an advantage that the weather resistance of the coating film is excellent.

  Next, the present invention will be described in more detail based on examples, but the present invention is not limited to such examples.

Production Example 1
In a flask equipped with a stirrer, dropping funnel, thermometer, reflux condenser and nitrogen gas inlet tube, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole [Otsuka Chemical Co., Ltd. Product name: RUVA93] 20 parts (parts by mass, the same applies hereinafter), 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine 2 parts, 2-hydroxyethyl methacrylate 15 parts, methyl A monomer mixture consisting of 54 parts of methacrylate and 9 parts of butyl acrylate, and 70 parts of ethyl acetate as a solvent were charged, and the temperature was raised to reflux temperature while flowing nitrogen gas and stirring.

  On the other hand, a mixture of 30 parts of ethyl acetate as a solvent and 0.2 part of 2,2′-azobis- (2-methylbutyronitrile) as a polymerization initiator was placed in a dropping tank and dropped into the flask over 2 hours. did. After completion of the dropwise addition, the reflux reaction was continued, cooled 6 hours after the start of the dropwise addition, diluted with ethyl acetate so that the solution had a nonvolatile content of 50% by mass, and a UV-absorbing copolymer having a weight average molecular weight of 95,000 ( Copolymer code A) listed in Table 1 was obtained.

  In each of the production examples, the weight-average molecular weight of the UV-absorbing copolymer is determined by gel permeation chromatography measuring apparatus [manufactured by Tosoh Corporation, product number: HLC8120] and column [manufactured by Tosoh Corporation, product number: TSK. -GEL GMHXL-L] was determined as a molecular weight in terms of polystyrene.

Production Examples 2-8
In Production Example 1, an ultraviolet-absorbing copolymer was prepared in the same manner as in Production Example 1 except that the composition of the monomer mixture was changed as shown in Table 1. In Production Example 8, no ultraviolet absorbing monomer is used, but for convenience, it is referred to as an ultraviolet absorbing copolymer.

Each abbreviation shown in Table 1 means the following.
(Ultraviolet absorbing monomer)
UVA1: 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole [monomer represented by the formula (I)]
UVA2: 2-hydroxy-4- (2-acryloyloxyethoxy) benzophenone [monomer represented by formula (II)]
UVA3: 2- [2-hydroxy-4- (2-methacryloyloxyethoxy) phenyl] -4,6-diphenyl-1,3,5-triazine [monomer represented by the formula (III)]
UVA4: 2- [2′-hydroxy-3′-methacryloylaminomethyl-5 ′-(1,1,3,3-tetramethylbutyl) phenyl] -2H-benzotriazole [represented by formula (IV) Monomer]

(UV stable monomer)
HALS: 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine [hydroxyl group-containing monomer]
HEMA: 2-hydroxyethyl methacrylate FM1D: 1-mol of ε-caprolactone adduct of 2-hydroxyethyl methacrylate [manufactured by Daicel Chemical Industries, Ltd., trade name: Plaxel FM1D]
[Other monomers]
・ MMA: Methyl methacrylate ・ BA: Butyl acrylate

Example 1
100 parts of the UV-absorbing copolymer A obtained in Production Example 1 (nonvolatile content is as described in Table 1), titanium oxide as a colorant [manufactured by Ishihara Sangyo Co., Ltd., trade name: Taipei CR-95 33.3 parts (pigment concentration in nonvolatile content: 40% by mass) was added and dispersed for 1 hour with a paint shaker to obtain a dispersion.

  10.6 parts of aliphatic polyisocyanate (burette-modified polyisocyanate) [manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Desmodur (registered trademark) N3200] as a crosslinking agent [in the dispersion] The hydroxyl group of the ultraviolet-absorbing copolymer / isocyanate group (equivalent ratio) of the aliphatic polyisocyanate: 1/1] was added. Then, it diluted with methyl ethyl ketone until the non volatile matter became 20 mass%, and obtained the curable resin composition.

  Next, the obtained curable resin composition was applied to a polyphenylene sulfide film having a thickness of 12 μm as a base film so that the thickness of the coating film after drying with a bar coater was 5 μm, and then at 100 ° C. for 1 minute. Then, it was dried at 50 ° C. for 1 day to form a coating film to obtain a coating film.

Examples 2-12 and Comparative Examples 1-3
In Example 1, a coating film was obtained in the same manner as in Example 1 except that the composition of the curable resin composition, the thickness of the coating film after drying, and the base film were changed as shown in Table 2. It was.

The details of the colorant, curing agent, and substrate described in Table 2 are as follows.
[Colorant]
Colorant A: Titanium oxide [Ishihara Sangyo Co., Ltd., trade name: CR-95]
Colorant B: Carbon black [Mitsubishi Chemical Corporation, trade name: MA100]
[Curing agent]
Aliphatic polyisocyanate (Buret-modified polyisocyanate) [manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Desmodur (registered trademark) N3200]
〔Base material〕
・ PPS: Polyphenylene sulfide film (thickness: 12 μm)
PET: Polyester film [manufactured by Toray Industries, Inc., trade name: Lumirror (registered trademark) X10S, thickness: 50 μm]

  Next, the physical properties of the coating films obtained in each Example and each Comparative Example were examined by the following method. The results are shown in Table 3.

[Moist heat adhesion]
The coated film was allowed to stand for 500 hours or 1000 hours in an atmosphere at 85 ° C. and a relative humidity of 85%. Thereafter, the cross-layer adhesion of the coating film of the coating film was examined.

  The cross-cut adhesion is evaluated in accordance with the description of JIS K 5600 5.6 (2004 edition), in the atmosphere at 25 ° C., through the coating film formed from the curable resin composition of the present invention, 100 grid cuts of 1 mm square reaching the base film were attached with a cutter knife using a 1 mm-spacing cutter guide, and cellophane adhesive tape [manufactured by Nichiban Co., Ltd., product number: CT405AP-18, width: 18 mm] Was attached to the cut surface, rubbed with an eraser from the top to completely adhere the tape, and then peeled off in the vertical direction to count the number of grids of the coating film remaining on the surface of the substrate film. In addition, the greater the number of grids of the coating film remaining on the surface of the base film, the better the wet heat adhesion.

The wet heat adhesion was evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: The number of grids of the remaining coating film is 95 or more. Δ: The number of grids of the remaining coating film is 80 to 94. ×: The number of grids of the remaining coating film is 79. Less than

[Curl resistance]
The curable resin composition is applied to a base film so that the film thickness after drying with a bar coater is 5 μm, and dried at 100 ° C. for 1 minute and then at 50 ° C. for 1 day to form a coating film. Within 30 minutes after the film is obtained, the coated film is cut at 23 ° C. in an atmosphere with a relative humidity of 65% to produce a test piece having a length of 10 cm and a width of 3 cm. For 3 hours, and the distance (lifting distance) between the four corners of the test piece and the horizontal base was measured, and the curl resistance A was evaluated based on the following evaluation criteria.

  In order to investigate the influence of wet heat, the coating film was cut in the atmosphere of 65% relative humidity at 23 ° C. in the same manner as described above to produce a test piece of 10 cm in length and 3 cm in width and coated on a horizontal table. Place the membrane on top, leave it in the atmosphere at 30 ° C and 80% relative humidity for 3 hours, measure the distance (lifting distance) between the four corners of the test piece and the horizontal base, and meet the following evaluation criteria Based on this, the curl resistance B was evaluated. In the same manner as described above, the coating film was cut at 23 ° C. in an atmosphere with a relative humidity of 65% to prepare a test piece having a length of 10 cm and a width of 3 cm, and placed on a horizontal table with the coating film facing upward. , Left at 30 ° C. in an atmosphere with a relative humidity of 80% for 6 hours, measure the distance (lifting distance) between the four corners of the test piece and the horizontal base, and based on the following evaluation criteria Curl resistance C Evaluated.

(Evaluation criteria)
○: Lifting distance is less than 3 mm (excellent curling resistance)
Δ: Lifting distance is 3 mm or more and less than 5 mm (good curl resistance)
×: Lifting distance is 5 mm or more (inferior in curling resistance)

〔Weatherability〕
Using ultraviolet ray deterioration acceleration tester [Iwasaki Electric Co., Ltd., trade name: iSuper UV Tester UV-W131], the coating film was irradiated with ultraviolet rays at 100 mW / cm ² in an atmosphere of 50% relative humidity at 60 ° C. The tensile strength of the coated film before and after irradiation was measured.

The tensile strength is obtained by cutting the coating film so as to have a width of 10 mm using a variable temperature tensile tester [manufactured by Shimadzu Corporation, trade name: Shimadzu Autograph AGS-100D]. The test piece was pulled in the air at 23 ° C. under conditions of a chuck distance of 40 mm and a tensile speed of 200 mm / min, and the tensile strength until breaking was measured. Tensile strength retention is given by the formula:
[Retention rate of tensile strength (%)] = [[Tensile strength after irradiation] − [Tensile strength before irradiation]] × 100
The weather resistance was evaluated based on the following evaluation criteria.

(Evaluation criteria)
○: Retention rate of tensile strength is 90% or more (excellent weather resistance)
Δ: Tensile strength retention is 70% or more and less than 90% (good weather resistance)
X: Retention rate of tensile strength is less than 70% (weather resistance is poor)

[Storage stability]
To 100 parts of each UV-absorbing copolymer obtained in Production Examples 1 to 8, 33.3 parts of titanium oxide [Ishihara Sangyo Co., Ltd., trade name: Taipei CR-95] was added as a colorant. The dispersion was obtained for 1 hour using a paint shaker to obtain a dispersion (concentration of titanium oxide in the nonvolatile content of the dispersion: 40% by mass). 10.6 parts of aliphatic polyisocyanate (burette-modified polyisocyanate) [manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Desmodur (registered trademark) N3200] is added to the obtained dispersion as a curing agent ( An equivalent ratio of the hydroxyl group in the UV-absorbing copolymer to the isocyanate group of the aliphatic polyisocyanate = 1: 1) was diluted with methyl ethyl ketone to prepare a paint having a nonvolatile content concentration of 20% by mass.

  The obtained paint was allowed to stand at 40 ° C. for 7 days, and then the paint was visually observed to evaluate the storage stability A based on the following evaluation criteria. Moreover, after leaving the obtained coating material to stand at 40 degreeC for 14 days, the coating material was observed visually and storage stability B was evaluated based on the following evaluation criteria. In Comparative Example 1, no test was performed because no colorant was used.

(Evaluation criteria)
○: No abnormality in the appearance of the paint (excellent storage stability)
Δ: Colorant in paint slightly settled (good storage stability)
×: Colorant completely settled in paint (storage stability is poor)

From the results shown in Tables 2 and 3, the following can be understood.
The curable resin composition described in Comparative Example 1 corresponds to the ultraviolet absorbing resin composition obtained in “Example 4” of JP 2008-56859 A, but in contrast to this resin composition, Each of the curable resin compositions obtained in each example is excellent in wet heat adhesion and storage stability with the base material, and all of the coating films formed from the curable resin composition are curl resistant. It can also be seen that the weather resistance is excellent.

  Further, in comparison with Comparative Example 1, in Example 9, ultraviolet rays obtained by polymerizing a monomer mixture in which an inorganic pigment, an ultraviolet absorbing monomer and an ultraviolet stable monomer were used in combination. It can be seen that since the absorbent copolymer is used, the weather resistance of the coating film is remarkably improved, and the wet heat adhesion and the curl resistance are improved.

  Further, from the comparison between Example 2 and Comparative Examples 2 and 3, a UV-absorbing monomer was used but a UV-stable monomer was not used (Comparative Example 2) and a UV-absorbing monomer was used. When the monomer is not used but the UV-stable monomer is used (Comparative Example 3), the wet heat adhesion with the substrate of the curable resin composition and the storage stability are poor, and the coating film In contrast, when the UV-absorbing monomer and the UV-stable monomer are used in combination (Example 2), the curable resin composition has wet heat adhesion. Further, it is found that the film is excellent in storage stability and the coating film is excellent in curling resistance and weather resistance.

  For this reason, the use of a UV-absorbing monomer or UV-stable monomer alone does not improve wet heat adhesion, curl resistance, weather resistance and storage stability. It can be seen that the combined use of UV and a UV-stable monomer improves wet heat adhesion, curl resistance, weather resistance and storage stability as a synergistic effect of the combined use of both.

  Further, when any of the UV-absorbing copolymers A to E is used, when the thickness of the coating film after drying is the same (Examples 1 to 6), the UV-absorbing monomer and When the mass ratio to the UV-stable monomer (UV-absorbing monomer / UV-stable monomer) is 10/1 to 40/1 (Examples 1, 3 and 5), wet heat adhesion, It can be seen that the curl resistance, weather resistance, and storage stability are all superior. Moreover, from the results of Examples 7 and 8, it can be seen that when the coating film after drying is thin, it is excellent in wet heat adhesion and curl resistance. Further, in Example 5, carbon black, which is a black pigment, is used as a colorant, and a film made of polyester is used as a base material. However, as in Example 1 in which a film made of polyphenylene sulfide is used. In addition, it can be seen that the film is excellent in wet heat adhesion, curl resistance, weather resistance and storage stability.

  From the above, the curable resin composition of the present invention uses a UV-absorbing monomer and a UV-stable monomer in combination, and as a synergistic effect of the combined use, wet heat adhesion, curl resistance It can be seen that both weather resistance and storage stability are excellent. Therefore, it turns out that the coating film obtained by apply | coating the curable resin composition of this invention to a base film can be used suitably as a solar cell backsheet, for example.

  The curable resin composition of the present invention includes, for example, a solar cell backsheet, a coating agent for protecting the contents and the substrate from ultraviolet rays, packaging materials such as chemicals and foods, and an ultraviolet absorbing layer on glass bottles. It can be used as a coating agent for forming. The curable resin composition of the present invention includes a coating agent for preventing discoloration of a colorant such as a dye, a pressure-sensitive adhesive or adhesive for bonding resin substrates such as a fluororesin film, a silicone resin or an acrylic resin. It can be used as a primer for the hard coat layer. Furthermore, the curable resin composition of the present invention can be used as an insulating coating agent for weatherable recording liquids, fiber treatment agents, insulating elements and display elements.

  The curable resin composition of the present invention includes, for example, a reversible thermosensitive recording material, a sublimation transfer recording material, a melt transfer recording material, an inkjet recording material, a thermosensitive recording material, an IC card, an IC tag, and the like. Packaging materials for chemicals and foods, solar cell backsheets, marking films, photosensitive resin plates, adhesive sheets, dye-sensitized solar cells, polymer solid electrolytes, UV absorbing insulating films, polarizing plate protecting resin films, reflection Resin films for prevention, optical diffusion films such as light diffusion films, glass scattering prevention resin films, decorative films, resin films for building materials such as window resin films, display materials, resin films for indoor and outdoor overlays It can be used as a shrink film.

Claims (5)

  A curable resin composition comprising a UV-absorbing copolymer obtained by polymerizing a monomer mixture containing a UV-absorbing monomer and a UV-stable monomer, a curing agent, and a colorant object. The ultraviolet absorbing monomer is represented by the formula (I):
Wherein R ¹ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 12 carbon atoms, R ² is an alkylene group having 1 to 6 carbon atoms, R ³ is a hydrogen atom or a methyl group, X ¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or 7 to 12 carbon atoms. Aralkyl, cyano or nitro)
A monomer represented by formula (II):
(Wherein R ⁴ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 12 carbon atoms, R ⁵ is a hydrogen atom or a methyl group, and R ⁶ is hydrogen. An atom or a hydroxyl group, R ⁷ is a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms, R ⁸ is an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group having 1 to 10 carbon atoms, X ² is an ester bond, an amide bond, Ether bond or urethane bond, m represents 0 or 1)
A monomer represented by formula (III):
[Wherein, R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or 2 to 2 carbon atoms. 10 is an alkenyl group or an alkoxy group having 1 to 10 carbon atoms, Y is a hydrogen atom or a methyl group, A is a — (CH ₂ CH ₂ O) _p — group (p is an integer of 1 to 20), —CH ₂ CH ( OH) —CH ₂ O— group, — (CH ₂ ) _p —O— group (p is the same as above), —CH ₂ CH (CH ₂ OR ¹⁷ ) —O— group (R ¹⁷ has 1 to 10 carbon atoms) Alkyl group), —CH ₂ CH (R ¹⁷ ) —O— group (R ¹⁷ is the same as above) or —CH ₂ (CH ₂ ) _q COO—B—O— group (B is a methylene group, ethylene group or —CH ₂ CH (OH) CH ₂ — group, q represents 0 or 1)]
And a monomer represented by the formula (IV):
Wherein R ¹⁸ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and R ¹⁹ is a group having an element capable of forming a hydrogen bond. R ²⁰ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms)
The curable resin composition according to claim 1, which is at least one monomer selected from the group consisting of monomers represented by: The UV stable monomer has the formula (V):
(Wherein R ²² is a hydrogen atom or a cyano group, R ²³ and R ²⁴ are each independently a hydrogen atom or a methyl group, R ²⁵ is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, Z is an oxygen atom or an imino group) Group)
The curable resin composition according to claim 1, wherein the curable resin composition is represented by the formula:   The curable resin composition according to any one of claims 1 to 3, wherein the ultraviolet-absorbing copolymer has a weight average molecular weight of 50,000 to 500,000.   The curable resin composition according to any one of claims 1 to 4, wherein the curing agent is a polyfunctional isocyanate compound.