JP2014047285A - Curable coating material composition for fluorinated resin molding and laminate cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable coating composition for a fluororesin molded body, which adheres to the fluororesin molded body without any special treatment and is excellent in antifouling property and weather resistance.
The present invention comprises a composite resin (A) in which a polysiloxane segment (a1) and a vinyl polymer segment (a2) having an alcoholic hydroxyl group are bonded, and a polyisocyanate (B), The content of the polysiloxane segment (a1) is 10 to 60% by weight with respect to the total solid content of the coating composition for a fluororesin molded body, and the content of polyisocyanate (B) is the fluororesin molded body. The coating composition for a fluororesin molded body, which is 5 to 50% by weight based on the total solid content of the coating composition for coating, and the fluororesin molded body coating composition applied to the cured fluororesin Then, the above-mentioned problems are solved by providing a laminated cured product obtained by curing.
[Selection figure] None

Description

  The present invention relates to a curable coating composition for a fluororesin molded body and a laminated cured product.

Fluorine resins characterized by containing fluorine, such as ethylene / tetrafluoroethylene copolymer (ETFE) and polytetrafluoroethylene (PTFE), have a high C—F bond energy, and are therefore weather resistant, particularly ultraviolet rays. It is known for its extremely high resistance to, and has been suitably used in outdoor applications where weather resistance is required. However, although the fluororesin molding has high surface free energy and water repellency, once organic dirt such as dust, dust and oil adheres, the adhesion is strong and can be removed well with natural force. There was a problem that I couldn't. In particular, ETFE films and the like that require transparency may be restricted in outdoor use due to the significant loss of transparency due to the effects of dirt.
Accordingly, there has been a demand for a paint that can additionally impart antifouling properties to a fluororesin molded body having high weather resistance, has good adhesion, and has high weather resistance of the coating film. However, because of the water and oil repellency of the fluororesin molded body, for example, as in Patent Document 1, a paint that contains a monomer that becomes a cross-linking point with a paint resin in the fluororesin, It was difficult to bond with resin.

JP 2011-222575 A

  An object of the present invention is to provide a curable coating composition for a fluororesin molded body that adheres to the fluororesin molded body without any special treatment and is excellent in antifouling property and weather resistance.

  The present invention comprises a polysiloxane segment (a1) having a structural unit represented by the general formula (1) and / or the general formula (2), a silanol group and / or a hydrolyzable silyl group, and an alcoholic hydroxyl group. The vinyl polymer segment (a2) having a composite resin (A) bonded by a bond represented by the general formula (3), and a polyisocyanate (B), containing the polysiloxane segment (a1) The rate is 10 to 60% by weight with respect to the total solid content of the coating composition for fluororesin moldings, and the content of polyisocyanate (B) is the total solid content of the coating composition for fluororesin moldings The coating composition for a fluororesin molded body, and the coating composition for a fluororesin molded body, which is characterized by being 5 to 50% by weight based on It was to provide a laminated cured product obtained, to solve the above problems.

（１）

(1)

（２）
（一般式（１）及び（２）中、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立して、−Ｒ^４−ＣＨ＝ＣＨ_２、−Ｒ^４−Ｃ（ＣＨ_３）＝ＣＨ_２、−Ｒ^４−Ｏ−ＣＯ−Ｃ（ＣＨ_３）＝ＣＨ_２、及び−Ｒ^４−Ｏ−ＣＯ−ＣＨ＝ＣＨ_２からなる群から選ばれる１つの重合性二重結合を有する基（但し、Ｒ^４は単結合又は炭素原子数１〜６のアルキレン基を表す。）、炭素原子数が１〜６のアルキル基、炭素原子数が３〜８のシクロアルキル基、アリール基、または炭素原子数が７〜１２のアラルキル基を表す）

(2)
(In the general formulas (1) and (2), R ¹ , R ² and R ³ are each independently -R ⁴ -CH = CH ₂ , -R ⁴ -C (CH ₃ ) = CH ₂ ,- A group having one polymerizable double bond selected from the group consisting of R ⁴ —O—CO—C (CH ₃ ) ═CH ₂ and —R ⁴ —O—CO—CH═CH ₂ (provided that R ⁴ Represents a single bond or an alkylene group having 1 to 6 carbon atoms.), An alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group, or 7 carbon atoms. Represents an aralkyl group of ˜12)

（３）
（一般式（３）中、炭素原子は前記ビニル系重合体セグメント（ａ２）の一部分を構成し、酸素原子のみに結合したケイ素原子は、前記ポリシロキサンセグメント（ａ１）の一部分を構成するものとする）

(3)
(In the general formula (3), carbon atoms constitute a part of the vinyl polymer segment (a2), and silicon atoms bonded only to oxygen atoms constitute a part of the polysiloxane segment (a1). To do)

  The composite resin (A) has a hydroxyl value of 50 mgKOH / g or less, and the curable coating composition for a fluororesin molded body and the fluororesin molded body coating composition are applied to a fluororesin and cured. A laminated cured product is provided.

  The composite resin (A) further comprises a fluorine atom-containing curable coating composition for a fluororesin molded body, and a laminate obtained by applying the fluororesin molded body coating composition to a fluororesin and curing it. Provide a cured product.

  By providing a curable coating composition for a fluororesin molded body containing the composite resin (A), the fluororesin molded body adheres to the fluororesin molded body without any special treatment, and is excellent in antifouling properties and long-term weather resistance. In addition, the problem of providing a curable coating composition for a fluororesin molded article can be solved. Moreover, the laminated cured material excellent in antifouling property and long-term weather resistance obtained by apply | coating and hardening this curable coating composition for fluororesin molded objects to a fluororesin molded object can be provided.

[Composite resin (A)]
The composite resin (A) used in the present invention is a polysiloxane having a structural unit represented by the general formula (1) and / or the general formula (2), and a silanol group and / or a hydrolyzable silyl group. Segment (a1) (hereinafter simply referred to as polysiloxane segment (a1)) and vinyl polymer segment (a2) having alcoholic hydroxyl group (hereinafter simply referred to as vinyl polymer segment (a2)) This is a composite resin (A) bonded by a bond represented by formula (3). The bond represented by the general formula (3) is particularly excellent in the alkali resistance of the obtained molded article and is preferable.

（３）

(3)

The silanol group and / or hydrolyzable silyl group possessed by the polysiloxane segment (a1) described later and the silanol group and / or hydrolyzable silyl group possessed by the vinyl polymer segment (a2) described below undergo a dehydration condensation reaction. Thus, the bond represented by the general formula (3) is generated. Accordingly, in the general formula (3), carbon atoms constitute a part of the vinyl polymer segment (a2), and silicon atoms bonded only to oxygen atoms constitute a part of the polysiloxane segment (a1). And
The form of the composite resin (A) is, for example, a composite resin having a graft structure in which the polysiloxane segment (a1) is chemically bonded as a side chain of the polymer segment (a2), or the polymer segment (a2). And a composite resin having a block structure in which the polysiloxane segment (a1) is chemically bonded.

[Polysiloxane segment (a1)]
The polysiloxane segment (a1) in the present invention is a segment having a structural unit represented by the general formula (1) and / or the general formula (2), a silanol group and / or a hydrolyzable silyl group. The structural unit represented by the general formula (1) and / or the general formula (2) includes a group having a polymerizable double bond.

(Structural unit represented by general formula (1) and / or general formula (2))
The structural unit represented by the general formula (1) and / or the general formula (2) has a group having a polymerizable double bond as an essential component.
Specifically, R ¹ , R ² and R ³ in the general formulas (1) and (2) are each independently —R ⁴ —CH═CH ₂ , —R ⁴ —C (CH ₃ ) = A group having one polymerizable double bond selected from the group consisting of CH ₂ , —R ⁴ —O—CO—C (CH ₃ ) ═CH ₂ , and —R ⁴ —O—CO—CH═CH ₂ ( R ⁴ represents a single bond or an alkylene group having 1 to 6 carbon atoms), an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group, or the number of carbon atoms. 7 to 12 aralkyl groups are represented, and at least one of R ¹ , R ² and R ³ is a group having the polymerizable double bond. Examples of the alkylene group having 1 to 6 carbon atoms in R ⁴ include a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, Pentylene group, isopentylene group, neopentylene group, tert-pentylene group, 1-methylbutylene group, 2-methylbutylene group, 1,2-dimethylpropylene group, 1-ethylpropylene group, hexylene group, isohesylene group, 1-methylpentylene Len group, 2-methylpentylene group, 3-methylpentylene group, 1,1-dimethylbutylene group, 1,2-dimethylbutylene group, 2,2-dimethylbutylene group, 1-ethylbutylene group, 1,1 , 2-trimethylpropylene group, 1,2,2-trimethylpropylene group, 1-ethyl-2 -A methylpropylene group, 1-ethyl-1-methylpropylene group, etc. are mentioned. Among these, R ⁴ is preferably a single bond or an alkylene group having 2 to 4 carbon atoms because of easy availability of raw materials.

Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and isopentyl. Group, neopentyl group, tert-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, 1-ethylpropyl group, hexyl group, isohexyl group, 1-methylpentyl group, 2-methylpentyl Group, 3-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 2,2-dimethylbutyl group, 1-ethylbutyl group, 1,1,2-trimethylpropyl group, 1,2 , 2-trimethylpropyl group, 1-ethyl-2-methylpropyl group, 1-ethyl-1-methylpropyl group, and the like.
Examples of the cycloalkyl group having 3 to 8 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the aryl group include a phenyl group, a naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-vinylphenyl group, and a 3-isopropylphenyl group.
Examples of the aralkyl group having 7 to 12 carbon atoms include a benzyl group, a diphenylmethyl group, and a naphthylmethyl group.

In the present invention, it is preferable that two or more polymerizable double bonds exist in the polysiloxane segment (a1), more preferably 3 to 200, and more preferably 3 to 50. Preferably, a molded product having excellent scratch resistance can be obtained. Specifically, if the content of the polymerizable double bond in the polysiloxane segment (a1) is 3 to 20% by weight, desired scratch resistance can be obtained.
Here, the calculation of the content of the polymerizable double bond is as follows. The molecular weight is 27 for a group having —CH═CH _2, and the molecular weight is 41 for a group having —C (CH ₃ ) ═CH _2. Calculated.

  The structural unit represented by the general formula (1) and / or the general formula (2) is a three-dimensional network polysiloxane structural unit in which two or three of the silicon bonds are involved in crosslinking. Since a dense network structure is not formed while a three-dimensional network structure is formed, gelation or the like does not occur during production, and the long-term storage stability of the resulting composite resin is improved.

(Silanol group and / or hydrolyzable silyl group)
In the present invention, the silanol group is a silicon-containing group having a hydroxyl group directly bonded to a silicon atom. Specifically, the silanol group is a silanol group formed by combining an oxygen atom having a bond with a hydrogen atom in the structural unit represented by the general formula (1) and / or the general formula (2). Preferably there is.

  In the present invention, the hydrolyzable silyl group is a silicon-containing group having a hydrolyzable group directly bonded to a silicon atom, and specifically includes, for example, a group represented by the general formula (4). .

（４）

(4)

(In the general formula (4), R ⁵ is a monovalent organic group such as an alkyl group, an aryl group or an aralkyl group, and R ⁶ is a halogen atom, an alkoxy group, an acyloxy group, a phenoxy group, an aryloxy group, a mercapto group, (It is a hydrolyzable group selected from the group consisting of an amino group, an amide group, an aminooxy group, an iminooxy group and an alkenyloxy group, and b is an integer of 0 to 2.)

Examples of the alkyl group in R ⁵ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a tert group. -Pentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, 1-ethylpropyl group, hexyl group, isohexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl Group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 2,2-dimethylbutyl group, 1-ethylbutyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group 1-ethyl-2-methylpropyl group, 1-ethyl-1-methylpropyl group and the like.
Examples of the aryl group include a phenyl group, a naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-vinylphenyl group, and a 3-isopropylphenyl group.
Examples of the aralkyl group include a benzyl group, a diphenylmethyl group, and a naphthylmethyl group.

In R ⁶ , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a second butoxy group, and a third butoxy group.
Examples of the acyloxy group include formyloxy, acetoxy, propanoyloxy, butanoyloxy, pivaloyloxy, pentanoyloxy, phenylacetoxy, acetoacetoxy, benzoyloxy, naphthoyloxy and the like.
Examples of the aryloxy group include phenyloxy and naphthyloxy.
Examples of the alkenyloxy group include a vinyloxy group, allyloxy group, 1-propenyloxy group, isopropenyloxy group, 2-butenyloxy group, 3-butenyloxy group, 2-petenyloxy group, 3-methyl-3-butenyloxy group, 2 -A hexenyloxy group etc. are mentioned.

By hydrolyzing the hydrolyzable group represented by R ⁶ , the hydrolyzable silyl group represented by the general formula (4) becomes a silanol group. Among these, a methoxy group and an ethoxy group are preferable because of excellent hydrolyzability.
The hydrolyzable silyl group specifically includes an oxygen atom having a bond in the structural unit represented by the general formula (1) and / or the general formula (2) bonded to the hydrolyzable group. Or it is preferable that it is the hydrolyzable silyl group substituted.

When the silanol group or the hydrolyzable silyl group is cured with active energy rays, the hydroxyl group in the silanol group or the hydrolyzable silyl group in the hydrolyzable silyl group is parallel to the active energy ray curing reaction. Since the hydrolysis-condensation reaction proceeds, the cross-linking density of the polysiloxane structure is increased, and a molded article having excellent solvent resistance can be formed.
In addition, the polysiloxane segment (a1) containing the silanol group or the hydrolyzable silyl group and the vinyl polymer segment (a2) having an alcoholic hydroxyl group described later are represented by the general formula (3). Used when connecting via

The polysiloxane segment (a1) is not particularly limited except that it has a structural unit represented by the general formula (1) and / or the general formula (2), and a silanol group and / or a hydrolyzable silyl group. Other groups may be included. For example,
Polysiloxanes R ¹ in the general formula (1) is a structural unit is a group having a polymerizable double bond, R ¹ in the general formula (1) coexist and the structural unit is an alkyl group such as methyl It may be segment (a1)
A structural unit R ¹ is an alkyl group such as a methyl group and structural units R ¹ is a group having a polymerizable double bond in the formula (1), the formula in (1), the general formula It may be a polysiloxane segment (a1) in which R ² and R ³ in (2) coexist with a structural unit that is an alkyl group such as a methyl group,
A structural unit in which R ¹ in the general formula (1) is a group having the polymerizable double bond, and a structural unit in which R ² and R ³ in the general formula (2) are alkyl groups such as a methyl group. The polysiloxane segment (a1) which coexists may be used, and there is no particular limitation.
Specifically, examples of the polysiloxane segment (a1) include those having the following structures.

  In the present invention, the polysiloxane segment (a1) is characterized by containing 10 to 60% by weight with respect to the total solid content of the coating composition for a fluororesin molded body, and is excellent in weather resistance.

[Vinyl polymer segment (a2) having an alcoholic hydroxyl group]
The vinyl polymer segment (a2) in the present invention is a vinyl polymer segment such as an acrylic polymer having an alcoholic hydroxyl group, a fluoroolefin polymer, a vinyl ester polymer, an aromatic vinyl polymer, and a polyolefin polymer. In particular, an acrylic polymer segment obtained by copolymerizing a (meth) acrylic monomer having an alcohol hydroxyl group is preferred because the resulting molded article is excellent in transparency and gloss.

Specific examples of the (meth) acrylic monomer having an alcohol hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) ) Acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl mono Various α such as butyl fumarate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, “Placcel FM or Plaxel FA” [Caprolactone addition monomer manufactured by Daicel Chemical Industries, Ltd.] Hydroxyalkyl esters of β- ethylenically unsaturated carboxylic acid or an adduct thereof with ε- caprolactone, and the like.
Of these, 2-hydroxyethyl (meth) acrylate is preferable because it is easy to react.

  The amount of alcoholic hydroxyl group contained in the composite resin (A) is more preferably 50 mgKOH / g or less. By setting the alcoholic hydroxyl group amount to 50 mgKOH / g or less, the hydrophilicity of the curable coating composition for a fluororesin molded body of the present invention can be kept low. This is because the adhesiveness between the curable coating composition for a fluororesin molded body and the fluororesin molded body can be further improved.

  There is no limitation in particular as another (meth) acryl monomer which can be copolymerized, It is possible to use a well-known monomer. Vinyl monomers can also be copolymerized. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) Alkyl (meth) acrylates having an alkyl group having 1 to 22 carbon atoms such as acrylate and lauryl (meth) acrylate; aralkyl (meth) acrylates such as benzyl (meth) acrylate and 2-phenylethyl (meth) acrylate Cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; ω-alkoxyalkyl such as 2-methoxyethyl (meth) acrylate and 4-methoxybutyl (meth) acrylate ( A) Acrylates; aromatic vinyl monomers such as styrene, p-tert-butylstyrene, α-methylstyrene, vinyltoluene, etc .; vinyl acetates such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate Alkyl esters of crotonic acid such as methyl crotonic acid and ethyl crotonic acid; dialkyl esters of unsaturated dibasic acids such as dimethyl malate, di-n-butyl maleate, dimethyl fumarate, dimethyl itaconate; ethylene, propylene Α-olefins such as vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, etc .; fluoroolefins such as ethyl vinyl ether, n-butyl vinyl ether; cyclopentyl Cycloalkyl vinyl ethers such as nyl ether and cyclohexyl vinyl ether; Tertiary amide group-containing monomers such as N, N-dimethyl (meth) acrylamide, N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidine and N-vinylpyrrolidone Etc.

  There are no particular limitations on the polymerization method, solvent, or polymerization initiator for copolymerizing the monomers, and the vinyl polymer segment (a2) can be obtained by a known method. For example, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-) can be obtained by various polymerization methods such as bulk radical polymerization, solution radical polymerization, and non-aqueous dispersion radical polymerization. Dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), tert-butylperoxypivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di- The vinyl polymer segment (a2) can be obtained by using a polymerization initiator such as tert-butyl peroxide, cumene hydroperoxide, diisopropyl peroxycarbonate or the like.

    The number average molecular weight of the vinyl polymer segment (a2) is preferably in the range of 500 to 200,000 in terms of number average molecular weight (hereinafter abbreviated as Mn), and the composite resin (A) is produced. It is possible to prevent thickening and gelation during the process, and the resulting molded article has excellent durability. Mn is more preferably in the range of 700 to 100,000, and still more preferably in the range of 1,000 to 50,000.

  In addition, the vinyl polymer segment (a2) is a vinyl polymer segment (A) in order to form a composite resin (A) bonded by the bond represented by the general formula (3) with the polysiloxane segment (a1). It has a silanol group and / or a hydrolyzable silyl group directly bonded to the carbon bond in a2). Since these silanol groups and / or hydrolyzable silyl groups become bonds represented by the general formula (3) in the production of the composite resin (A) described later, the composite resin (A ) In the vinyl polymer segment (a2). However, there is no problem even if silanol groups and / or hydrolyzable silyl groups remain in the vinyl polymer segment (a2), and during the curing with active energy rays, in parallel with the active energy ray curing reaction, Since the hydrolysis and condensation reaction proceeds between the hydroxyl groups in the silanol group and the hydrolyzable groups in the hydrolyzable silyl group, the crosslink density of the polysiloxane structure is increased, and a molded product with excellent solvent resistance is formed. can do.

Specifically, the vinyl polymer segment (a2) having a silanol group and / or a hydrolyzable silyl group directly bonded to a carbon bond is a (meth) acryl monomer having the alcohol hydroxyl group, the general-purpose monomer, and It is obtained by copolymerizing a vinyl monomer containing a silanol group and / or a hydrolyzable silyl group directly bonded to a carbon bond.
Examples of vinyl monomers containing a silanol group and / or a hydrolyzable silyl group directly bonded to a carbon bond include vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinyltri (2-methoxyethoxy) silane. , Vinyltriacetoxysilane, vinyltrichlorosilane, 2-trimethoxysilylethyl vinyl ether, 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyl Examples include methyldimethoxysilane and 3- (meth) acryloyloxypropyltrichlorosilane. Among these, vinyltrimethoxysilane and 3- (meth) acryloyloxypropyltrimethoxysilane are preferable because the hydrolysis reaction can easily proceed and by-products after the reaction can be easily removed.

It is preferable that the coating composition for a fluororesin molded body of the present invention contains a fluorine atom because adhesion to the fluororesin molded body is improved. Examples of the method in which the coating composition for a fluororesin molded body contains a fluorine atom include: 1. a method of introducing a fluorine atom into the vinyl polymer segment (a2); 2. a method of introducing fluorine atoms into the polysiloxane segment (a1); A method of using a fluorine atom-containing reactive compound in the composition can be used.

In order to introduce a fluorine atom into the vinyl polymer segment (a2), it is preferable to use a radical polymerizable unsaturated monomer containing a fluorinated alkyl group.

(Radically polymerizable unsaturated monomer having a fluorinated alkyl group)
Fluorinated alkyl group (functional group in which 1 or 2 or more carbon atoms to which 1 to 3 fluorine atoms are bonded are connected, carbon atom in the fluorinated alkyl group is an unsaturated bond, fluorinated alkyl Examples of the radical polymerizable unsaturated monomer having a carbon atom in the group linked by an ether bond with an oxygen atom include monomers represented by the following general formula (1).

(In the general formula (1), R represents a hydrogen atom, a fluorine atom, a methyl group, a cyano group, a phenyl group, a benzyl group, or -CnH2n-Rf '(n represents an integer of 1 to 8, and Rf' represents the following formula) (Rf-1) to (Rf-7) represents one group), and R ′ represents any one of the following formulas (R′-1) to (R′-10). Rf represents any one group of the following formulas (Rf-1) to (Rf-7).

(N in the above formulas (R′-1), (R′-3), (R′-5), (R′-6) and (R′-7) represents an integer of 1 to 8.) M in the formulas (R′-8), (R′-9) and (R′-10) represents an integer of 1 to 8, and n represents an integer of 0 to 8. The above formula (R′-6) ) And (R′-7
) In R) represents any one of the following formulas (Rf-1) to (Rf-7). )

(In the formulas (Rf-1) and (Rf-2), n represents an integer of 1 to 6. The formula (Rf-3
N in) represents an integer of 2-6. N in the above formula (Rf-4) represents an integer of 4 to 6. M in the said formula (Rf-5) is an integer of 1-5, n is an integer of 0-4, and the sum total of m and n is 1-5. M in the formula (Rf-6) is an integer of 0 to 4, n is an integer of 1 to 4, p is an integer of 0 to 4, and the sum of m, n, and p is 1 to 4. 5. )

More specific examples of the preferred monomer (f1) include the following monomers (f1-1) to (f1-15).

(The above formulas (f1-6), (f1-7), (f1-13), (f1-14) and (f1-
N in 13) represents 3 or 5. )

  Further, a compound having a poly (perfluoroalkylene ether) chain and a structural portion having a radical polymerizable group at both ends thereof may be used.

  Those represented by the structural formulas F-1 to F-10 can be given. In the above structural formulas, “—PFPE—” represents a poly (perfluoroalkylene ether) chain.

The structure for introducing a fluorine atom into the polysiloxane segment (a1) is such that a part or all of the hydrogen atoms of the alkyl group, cycloalkyl group, aryl group, and aralkyl group in the polysiloxane segment (a1) described above are present. A group substituted with a fluorine atom, specifically a fluoroalkyl group having 1 to 6 carbon atoms, a polyfluoroalkyl group, a perfluoroalkyl group; or a fluoro having 3 to 8 carbon atoms A cycloalkyl group, a polyfluorocycloalkyl group, a perfluorocycloalkyl group; or a fluoroaryl group, a polyfluoroaryl group, a perfluoroaryl group; or a fluoroaralkyl group having 7 to 12 carbon atoms, a polyfluoroaralkyl group, a perfluoroalkyl group A fluoroaralkyl group; and the like,
Examples include a fluoroalkyl group, a difluoroalkyl group, a trifluoroalkyl group, a polyfluoroalkyl group, and the like, and a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and the like. It is done.

  A method of using a fluorine atom-containing reactive compound in the composition is to use a silane coupling agent having a fluorinated alkyl group, for example, trifluoropropyltrimethoxysilane, etc. And Shin-Etsu Chemical Co., Ltd. KBM-7013.

[Production method of composite resin (A)]
Specifically, the composite resin (A) used in the present invention is produced by the methods shown in the following (Method 1) to (Method 3).

(Method 1) (Meth) acrylic monomer having alcohol hydroxyl group, general-purpose (meth) acrylic monomer, etc., and vinyl monomer containing silanol group and / or hydrolyzable silyl group directly bonded to carbon bond To obtain a vinyl polymer segment (a2) containing a silanol group and / or a hydrolyzable silyl group directly bonded to a carbon bond. A silane compound having both a silanol group and / or a hydrolyzable silyl group and a polymerizable double bond, and, if necessary, a general-purpose silane compound are mixed and subjected to a hydrolysis condensation reaction.
In this method, a silanol group and / or hydrolyzable silyl group and a silanol group or hydrolyzable silyl group of a silane compound having both a polymerizable double bond and a silanol group and / or hydrolyzed directly bonded to a carbon bond. The silanol group and / or hydrolyzable silyl group of the vinyl polymer segment (a2) containing a functional silyl group undergoes a hydrolytic condensation reaction to form the polysiloxane segment (a1), and the polysiloxane The composite resin (A) in which the segment (a1) and the vinyl polymer segment (a2) having an alcoholic hydroxyl group are combined by the bond represented by the general formula (3) is obtained.

(Method 2) In the same manner as in Method 1, a vinyl polymer segment (a2) containing a silanol group and / or a hydrolyzable silyl group directly bonded to a carbon bond is obtained.
On the other hand, a polysiloxane segment (a1) is obtained by subjecting a silane compound having both a silanol group and / or a hydrolyzable silyl group and a polymerizable double bond and, if necessary, a general-purpose silane compound to a hydrolysis condensation reaction. Then, the silanol group and / or hydrolyzable silyl group of the vinyl polymer segment (a2) and the silanol group and / or hydrolyzable silyl group of the polysiloxane segment (a1) are hydrolyzed and condensed. Let

  (Method 3) Similarly to Method 1, a vinyl polymer segment (a2) containing a silanol group and / or a hydrolyzable silyl group directly bonded to a carbon bond is obtained. On the other hand, the polysiloxane segment (a1) is obtained in the same manner as in Method 2. Furthermore, a silane compound containing a silane compound having a polymerizable double bond and a general-purpose silane compound as necessary are mixed and subjected to a hydrolysis condensation reaction.

  Specific examples of the silane compound having both a silanol group and / or a hydrolyzable silyl group and a polymerizable double bond used in the (Method 1) to (Method 3) include, for example, vinyltrimethoxysilane, Vinyltriethoxysilane, vinylmethyldimethoxysilane, vinyltri (2-methoxyethoxy) silane, vinyltriacetoxysilane, vinyltrichlorosilane, 2-trimethoxysilylethyl vinyl ether, 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (Meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropyltrichlorosilane and the like. Among these, vinyltrimethoxysilane and 3- (meth) acryloyloxypropyltrimethoxysilane are preferable because the hydrolysis reaction can easily proceed and by-products after the reaction can be easily removed.

  Examples of the general-purpose silane compound used in the (Method 1) to (Method 3) include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, and n-propyl. Various organotrialkoxysilanes such as trimethoxysilane, iso-butyltrimethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane Various diorganodialkoxysilanes such as diethyldimethoxysilane, diphenyldimethoxysilane, methylcyclohexyldimethoxysilane, and methylphenyldimethoxysilane; Chill trichlorosilane, phenyl trichlorosilane, vinyl trichlorosilane, dimethyl dichlorosilane, chlorosilane such as diethyl dichlorosilane or diphenyl dichlorosilane and the like. Of these, organotrialkoxysilanes and diorganodialkoxysilanes that can easily undergo a hydrolysis reaction and easily remove by-products after the reaction are preferable.

Further, when the polysiloxane segment (a1) has an epoxy group, an epoxy group-containing silane compound may be used.
Epoxy group-containing silane compounds include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriacetoxysilane, β -(3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltriacetoxysilane, γ-glycidoxypropyldimethoxymethylsilane, γ-glycidoxypropyldiethoxymethylsilane, γ-glycidoxypropyldimethoxyethoxymethylsilane, γ-glycidoxypropyldiacetoxy Methylsilane, β- (3,4-epoxycyclohexyl) ethyldimethoxymethylsilane, β- (3,4-epoxycyclohexyl) ethyldiethoxymethylsilane, β- (3,4-epoxycyclohexyl) ethyldimethoxyethoxymethylsilane, β -(3,4-epoxycyclohexyl) ethyldiacetoxymethylsilane, γ-glycidoxypropyldimethoxyethylsilane, γ-glycidoxypropyldiethoxyethylsilane, γ-glycidoxypropyldimethoxyethoxyethylsilane, γ-glycyl Sidoxypropyldiacetoxyethylsilane, β- (3,4-epoxycyclohexyl) ethyldimethoxyethylsilane, β- (3,4-epoxycyclohexyl) ethyldiethoxyethylsilane, β- (3,4-epoxycyclohexyl) Tildimethoxyethoxyethylsilane, β- (3,4-epoxycyclohexyl) ethyldiacetoxyethylsilane, γ-glycidoxypropyldimethoxyisopropylsilane, γ-glycidoxypropyldiethoxyisopropylsilane, γ-glycidoxypropyldimethoxy Ethoxyisopropylsilane, γ-glycidoxypropyldiacetoxyisopropylsilane, β- (3,4-epoxycyclohexyl) ethyldiethoxyisopropylsilane, β- (3,4-epoxycyclohexyl) ethyldiethoxyisopropylsilane, β- ( 3,4-epoxycyclohexyl) ethyldimethoxyethoxyisopropylsilane, β- (3,4-epoxycyclohexyl) ethyldiacetoxyisopropylsilane, γ-glycidoxypropylmethoxydi Methylsilane, γ-glycidoxypropylethoxydimethylsilane, γ-glycidoxypropylmethoxyethoxydimethylsilane, γ-glycidoxypropylacetoxydimethylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxydimethylsilane, β- (3,4-epoxycyclohexyl) ethylethoxydimethylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyethoxydimethylsilane, β- (3,4-epoxycyclohexyl) ethylacetoxydimethylsilane, γ-glycidoxypropyl Methoxydiethylsilane, γ-glycidoxypropylethoxydiethylsilane, γ-glycidoxypropylmethoxyethoxydiethylsilane, γ-glycidoxypropylacetoxydiethylsilane, β- (3,4-epoxy Cyclohexyl) ethylmethoxydiethylsilane, β- (3,4-epoxycyclohexyl) ethylethoxydiethylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyethoxydiethylsilane, β- (3,4-epoxycyclohexyl) ethylacetoxy Diethylsilane, γ-glycidoxypropylmethoxydiisopropylsilane, γ-glycidoxypropylethoxydiisopropylsilane, γ-glycidoxypropylmethoxyethoxydiisopropylsilane, γ-glycidoxypropylacetoxydiisopropylsilane, β- (3,4) -Epoxycyclohexyl) ethylmethoxydiisopropylsilane, β- (3,4-epoxycyclohexyl) ethylethoxydiisopropylsilane, β- (3,4-epoxycyclohexyl) Tylmethoxyethoxydiisopropylsilane, β- (3,4-epoxycyclohexyl) ethylacetoxydiisopropylsilane, γ-glycidoxypropylmethoxyethoxymethylsilane, γ-glycidoxypropylacetoxymethoxymethylsilane, γ-glycidoxypropylacetoxy Ethoxymethylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyethoxymethylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyacetoxymethylsilane, β- (3,4-epoxycyclohexyl) ethylethoxyacetoxymethyl Silane, γ-glycidoxypropylmethoxyethoxyethylsilane, γ-glycidoxypropylacetoxymethoxyethylsilane, γ-glycidoxypropylacetoxyethoxyethylsila , Β- (3,4-epoxycyclohexyl) ethylmethoxyethoxyethylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyacetoxyethylsilane, β- (3,4-epoxycyclohexyl) ethylethoxyacetoxyethylsilane, γ -Glycidoxypropylmethoxyethoxyisopropylsilane, γ-glycidoxypropylacetoxymethoxyisopropylsilane, γ-glycidoxypropylacetoxyethoxyisopropylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyethoxyisopropylsilane, β- (3,4-epoxycyclohexyl) ethylmethoxyacetoxyisopropylsilane, β- (3,4-epoxycyclohexyl) ethylethoxyacetoxyisopropylsilane, glycidoxymethyl Rutrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxymethyltrimethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxymethyltrimethoxy Silane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxy Silane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxy Silane, β-glycy Xylbutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxy Silane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltryptoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- ( 3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxy (Cyclohexyl) butyl Liethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxy Silane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropyl Methyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ Glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylethyldipropoxy Examples thereof include silane, γ-glycidoxypropylvinyldimethoxysilane, and γ-glycidoxypropylvinyldiethoxysilane.

  In addition, a tetrafunctional alkoxysilane compound such as tetramethoxysilane, tetraethoxysilane or tetra n-propoxysilane or a partial hydrolysis condensate of the tetrafunctional alkoxysilane compound may be used in combination as long as the effects of the present invention are not impaired. it can. When the tetrafunctional alkoxysilane compound or a partially hydrolyzed condensate thereof is used in combination, the silicon atoms of the tetrafunctional alkoxysilane compound are 20 with respect to the total silicon atoms constituting the polysiloxane segment (a1). It is preferable to use together so that it may become the range which does not exceed mol%.

  In addition, a metal alkoxide compound other than a silicon atom such as boron, titanium, zirconium or aluminum can be used in combination with the silane compound as long as the effects of the present invention are not impaired. For example, it is preferable to use the metal alkoxide compound in combination in a range not exceeding 25 mol% with respect to all silicon atoms constituting the polysiloxane segment (a1).

  In the hydrolysis condensation reaction in the (Method 1) to (Method 3), a part of the hydrolyzable group is hydrolyzed under the influence of water or the like to form a hydroxyl group, and then the hydroxyl groups or the hydroxyl group and the hydrolysis are hydrolyzed. This refers to a proceeding condensation reaction that proceeds with a functional group. The hydrolysis-condensation reaction can be performed by a known method, but a method in which the reaction is advanced by supplying water and a catalyst in the production process is simple and preferable.

  Examples of the catalyst used include inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid; organic acids such as p-toluenesulfonic acid, monoisopropyl phosphate and acetic acid; inorganic bases such as sodium hydroxide and potassium hydroxide; tetraisopropyl titanate , Titanates such as tetrabutyl titanate; 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), 1,5-diazabicyclo [4.3.0] nonene-5 (DBN), 1 Compounds containing various basic nitrogen atoms, such as 1,4-diazabicyclo [2.2.2] octane (DABCO), tri-n-butylamine, dimethylbenzylamine, monoethanolamine, imidazole, 1-methylimidazole; Tetramethylammonium salt, tetrabutylammonium salt, dilauryldimethylammonium Quaternary ammonium salts having chloride, bromide, carboxylate or hydroxide as a counter anion; dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diacetylacetate Examples thereof include tin carboxylates such as narate, tin octylate and tin stearate. A catalyst may be used independently and may be used together 2 or more types.

    The amount of the catalyst to be added is not particularly limited, but generally it is preferably used in the range of 0.0001 to 10% by weight with respect to the total amount of each compound having the silanol group or hydrolyzable silyl group. , More preferably in the range of 0.0005 to 3% by weight, and particularly preferably in the range of 0.001 to 1% by weight.

The amount of water to be supplied is preferably 0.05 mol or more with respect to 1 mol of the silanol group or hydrolyzable silyl group of each compound having the silanol group or hydrolyzable silyl group, The above is more preferable, and particularly preferably 0.5 mol or more.
These catalyst and water may be supplied collectively or sequentially, or may be supplied by previously mixing the catalyst and water.

    The reaction temperature for carrying out the hydrolytic condensation reaction in the above (Method 1) to (Method 3) is suitably in the range of 0 ° C to 150 ° C, and preferably in the range of 20 ° C to 100 ° C. The reaction can be carried out under any conditions of normal pressure, increased pressure, or reduced pressure. Moreover, you may remove the alcohol and water which are the by-products which can be produced | generated in the said hydrolysis-condensation reaction by methods, such as distillation, as needed.

  The charging ratio of each compound in the (Method 1) to (Method 3) is appropriately selected depending on the desired structure of the composite resin (A) used in the present invention. Among them, it is preferable to obtain the composite resin (A) such that the content of the polysiloxane segment (a1) is 30 to 80% by weight because the molded article obtained is excellent in durability. Further preferred.

  In the above (Method 1) to (Method 3), as a specific method of combining the polysiloxane segment (a1) and the vinyl polymer segment (a2) in a block shape, only one end or both ends of the polymer chain is used. The vinyl polymer segment having a structure having a silanol group and / or a hydrolyzable silyl group as described above is used as an intermediate. For example, in the case of (Method 1), the vinyl polymer segment is added to the silanol group. Examples include a method in which a silane compound having both a group and / or a hydrolyzable silyl group and a polymerizable double bond and, if necessary, a general-purpose silane compound are mixed and subjected to a hydrolytic condensation reaction.

  On the other hand, in the above (Method 1) to (Method 3), as a specific method of complexing the polysiloxane segment (a1) in a graft form with the vinyl polymer segment (a2), a vinyl polymer segment is used. The vinyl polymer segment having a structure in which silanol groups and / or hydrolyzable silyl groups are randomly distributed is used as an intermediate for the main chain of, for example, (Method 2) Examples thereof include a method of subjecting the silanol group and / or hydrolyzable silyl group of the vinyl polymer segment and the silanol group and / or hydrolyzable silyl group of the polysiloxane segment to a hydrolytic condensation reaction. .

(Fluoropolymer molded article coating composition polyisocyanate (B))
The coating composition for fluororesin moldings used in the present invention contains 5 to 50% by weight of polyisocyanate (B) with respect to the total solid content of the coating composition for fluororesin moldings.
By containing the polyisocyanate in this range, a molded article having particularly excellent long-term weather resistance outdoors (specifically, crack resistance) can be obtained. This is because the polyisocyanate reacts with a hydroxyl group in the system (this is a hydroxyl group in the active energy ray-curable monomer having a hydroxyl group in the vinyl polymer segment (a2) or an alcoholic hydroxyl group described later). Thus, it is estimated that a urethane bond, which is a soft segment, is formed and functions to relieve stress concentration due to curing derived from a polymerizable double bond.

  When the content of the polyisocyanate (B) is less than 5% by weight with respect to the total solid content of the coating composition for a fluororesin molded article, the molded article obtained from the composition has cracks in long-term outdoor exposure. The problem that occurs occurs. On the other hand, when the content of polyisocyanate (B) is higher than 50% by weight with respect to the total solid content of the coating composition for a fluororesin molded body, there is a problem that the scratch resistance of the molded body is remarkably lowered. Arise.

  The polyisocyanate (B) to be used is not particularly limited and known ones can be used, but aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane-4,4′-diisocyanate, meta-xylylene diisocyanate, Polyisocyanates mainly composed of aralkyl diisocyanates such as α, α, α ', α'-tetramethyl-meta-xylylene diisocyanate are used because of the problem that the molded product is yellowed after long-term outdoor exposure. It is preferred to minimize the amount.

  From the viewpoint of long-term outdoor use, the polyisocyanate used in the present invention is preferably an aliphatic polyisocyanate containing an aliphatic diisocyanate as a main raw material. Examples of the aliphatic diisocyanate include tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (hereinafter abbreviated as “HDI”), 2,2,4- (or 2,4,4). Trimethyl-1,6-hexamethylene diisocyanate, lysine isocyanate, isophorone diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,4-diisocyanate cyclohexane, 1,3-bis (diisocyanate methyl) cyclohexane, 4,4 Examples include '-dicyclohexylmethane diisocyanate, etc. Among them, HDI is particularly preferable from the viewpoint of crack resistance and cost.

  Examples of the aliphatic polyisocyanate obtained from the aliphatic diisocyanate include allophanate type polyisocyanate, biuret type polyisocyanate, adduct type polyisocyanate, and isocyanurate type polyisocyanate, and any of them can be suitably used.

    In addition, as the above-described polyisocyanate, so-called blocked polyisocyanate compounds blocked with various blocking agents can be used. Examples of the blocking agent include alcohols such as methanol, ethanol and lactic acid esters; phenolic hydroxyl group-containing compounds such as phenol and salicylic acid esters; amides such as ε-caprolactam and 2-pyrrolidone; oximes such as acetone oxime and methyl ethyl ketoxime Active methylene compounds such as methyl acetoacetate, ethyl acetoacetate and acetylacetone can be used.

The isocyanate group in the polyisocyanate (B) is preferably 3 to 30% by weight based on the total solid content of the polyisocyanate from the viewpoint of crack resistance and scratch resistance of the resulting cured coating film. When the isocyanate group in (B) is less than 3%, the reactivity of the polyisocyanate is low and the scratch resistance is remarkably reduced. When the isocyanate group is more than 30%, the molecular weight of the polyisocyanate becomes small and the resistance to stress relaxation is reduced. Care must be taken since cracking will not be manifested.
The reaction between the polyisocyanate and the hydroxyl group in the system (this is a hydroxyl group in the active energy ray-curable monomer having a hydroxyl group in the vinyl polymer segment (a2) or an alcoholic hydroxyl group described later) is particularly heated. For example, when the cured form is UV, it reacts gradually by being left at room temperature after coating and UV irradiation. Moreover, you may accelerate | stimulate reaction of alcoholic hydroxyl group and isocyanate by heating for several minutes-several hours (20 minutes-4 hours) at 80 degreeC after UV irradiation as needed. In that case, you may use a well-known urethanation catalyst as needed. The urethanization catalyst is appropriately selected according to the desired reaction temperature.

When the coating composition for a fluororesin molded body used in the present invention is cured with ultraviolet rays, which are active energy rays, it is preferable to use a photopolymerization initiator. Known photopolymerization initiators may be used, and for example, one or more selected from the group consisting of acetophenones, benzyl ketals, and benzophenones can be preferably used. Examples of the acetophenones include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4 -(2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone and the like. Examples of the benzyl ketals include 1-hydroxycyclohexyl-phenyl ketone and benzyl dimethyl ketal. Examples of the benzophenones include benzophenone and methyl o-benzoylbenzoate. Examples of the benzoins include benzoin, benzoin methyl ether, and benzoin isopropyl ether. A photoinitiator (B) may be used independently and may use 2 or more types together.
The amount of the photopolymerization initiator (B) used is preferably 1 to 15% by weight and more preferably 2 to 10% by weight with respect to 100% by weight of the composite resin (A).

Moreover, when making it ultraviolet-harden, it is preferable to contain polyfunctional (meth) acrylate as needed. As described above, the polyfunctional (meth) acrylate is preferably one having an alcoholic hydroxyl group because it is reacted with the polyisocyanate (B). For example, 1,2-ethanediol diacrylate, 1,2-propanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, Tripropylene glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, tris (2-acryloyloxy) isocyanurate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, di (trimethylolpropane) tetraacrylate, di (penta Erythritol) pentaacrylate, di (pentaerythritol) hexaacrylate, etc. have two or more polymerizable double bonds in one molecule That polyfunctional (meth) acrylate. Moreover, urethane acrylate, polyester acrylate, epoxy acrylate, etc. can be illustrated as polyfunctional acrylate. These may be used alone or in combination of two or more.
In particular, pentaerythritol triacrylate and dipentaerythritol pentaacrylate are preferred from the viewpoint of scratch resistance of the cured coating film and the improvement of crack resistance due to reaction with polyisocyanate.

  In addition, a monofunctional (meth) acrylate can be used in combination with the polyfunctional (meth) acrylate. For example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate (for example, “Plexel” manufactured by Daicel Chemical Industries), phthalic acid and propylene Mono (meth) acrylate of polyester diol obtained from glycol, mono (meth) acrylate of polyester diol obtained from succinic acid and propylene glycol, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, pentaerythritol Tri (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, (meth) acrylate of various epoxy esters Hydroxyl group-containing (meth) acrylic acid esters such as phosphoric acid adducts; carboxyl group-containing vinyl monomers such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid; vinyl sulfonic acid, styrene sulfone Sulfonic acid group-containing vinyl monomers such as acid and sulfoethyl (meth) acrylate; 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxypropyl acid phosphate, 2- (meth) acryloyloxy-3- Examples thereof include acidic phosphate ester vinyl monomers such as chloro-propyl acid phosphate and 2-methacryloyloxyethylphenyl phosphoric acid; vinyl monomers having a methylol group such as N-methylol (meth) acrylamide. These can use 1 type (s) or 2 or more types. Considering the reactivity of the polyfunctional isocyanate (b) with the isocyanate group, the monomer (c) is particularly preferably a (meth) acrylic acid ester having a hydroxyl group.

    As the usage-amount in the case of using the said polyfunctional acrylate (C), 1 to 85 weight% is preferable with respect to the total solid content of the coating composition for fluororesin moldings used by this invention, and 5 to 80 weight% is preferable. More preferred. By using the polyfunctional acrylate within the above range, physical properties such as hardness of the obtained molded product can be improved.

  For example, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, an argon laser, a helium / cadmium laser, or an ultraviolet light-emitting diode can be used as the light used for ultraviolet curing. Using these, it is possible to cure by irradiating the application surface of the coating composition for a fluororesin molding with ultraviolet rays having a wavelength of about 180 to 400 nm. The irradiation amount of ultraviolet rays is appropriately selected depending on the type and amount of the photopolymerization initiator used.

On the other hand, when thermosetting the coating composition for a fluororesin molded body used in the present invention, the reaction temperature of the polymerizable double bond reaction in the composition and the urethanization reaction between an alcoholic hydroxyl group and an isocyanate, It is preferable to select each catalyst in consideration of the reaction time and the like.
Moreover, it is also possible to use a thermosetting resin together. Examples of the thermosetting resin include vinyl resins, unsaturated polyester resins, polyurethane resins, epoxy resins, epoxy ester resins, acrylic resins, phenol resins, petroleum resins, ketone resins, silicon resins, and modified resins thereof.

  Moreover, in order to adjust the viscosity at the time of coating, you may contain the organic solvent. Examples of the organic solvent include aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, n-octane, cyclohexane and cyclopentane; aromatic hydrocarbons such as toluene, xylene and ethylbenzene. Alcohols such as methanol, ethanol, n-butanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether; ethyl acetate, butyl acetate, n-butyl acetate, n-amyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl Esters such as ether acetate; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone and cyclohexanone; diethylene glycol dimethyl ether, diethylene glycol dibuty Polyalkylene glycol dialkyl ethers such as ethers; ethers such as 1,2-dimethoxyethane, tetrahydrofuran and dioxane; N-methylpyrrolidone, dimethylformamide, dimethylacetamide or ethylene carbonate used alone or in combination of two or more Can be used.

  In addition, the fluororesin molded body coating composition used in the present invention includes an organic solvent, an inorganic pigment, an organic pigment, an extender pigment, a clay mineral, a wax, a surfactant, a stabilizer, a flow regulator, as necessary. Various additives such as dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, or plasticizers can also be used.

  Since the composite resin (A) contained in the fluororesin molded body coating composition used in the present invention has both the polysiloxane segment (a1) and the vinyl polymer segment (a2), the surface smoothness of the coating film The silicon resin capable of improving the above and the like, and the acrylic resin and the active energy ray-curable monomer are relatively easily compatible. Therefore, a composition having good compatibility can be obtained.

  As the fluororesin molded product to which the resin composition described in the present invention is applied, any of a thermoplastic resin molded product and a thermosetting resin molded product can be suitably applied.

  Examples of fluoroplastic moldings include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, perfluoroalkoxy fluororesin, tetrafluoroethylene / hexafluoropropylene copolymer, ethylene Tetrafluoroethylene copolymer, ethylene / chlorotrifluoroethylene copolymer, and the like can be used. These can be melt molded by applying heat and then cooled to form a fluororesin molded body.

  Fluorine-based thermosetting resin moldings are those obtained by reacting and curing a fluorine-based compound having a polymerizable functional group using heat or active energy rays, and radical polymerization having a fluorinated alkyl group as described above. It can be obtained by curing a composition containing a polymerizable unsaturated monomer or the like.

[Laminated cured product]
The laminated cured product of the present invention can be obtained by applying and curing the curable composition for a fluororesin molded body on the fluororesin molded body. The shape of the fluororesin molded body is not particularly limited, and may be, for example, a sheet shape, a plate shape, a spherical shape, a film shape or a large structure, or an assembly or molded product having a complicated shape.

There is no restriction | limiting in particular as a method of apply | coating the said curable composition for fluororesin molded objects with respect to the said fluororesin molded object, If a range which does not impair the effect of invention, a well-known and usual method can be used. .
For example, the curable composition for a fluororesin molded body is obtained by a known and common coating method such as a brush coating method, a roller coating method, a spray coating method, a dip coating method, a flow coater coating method, a roll coater coating method or an electrodeposition coating method. It is preferable to provide a layer.
Further, when the fluororesin molded body is a sheet, the curable composition layer for fluororesin molded body is coated with a flow coater, a roll coater, a spraying method, an airless spray method, an air spray method, brush coating, roller coating, or iron coating. , A dipping method, a pulling method, a nozzle method, a winding method, a sink method, a piling method, a patching method, and the like.

[Use]
Since the laminated cured product of the present invention is excellent in weather resistance and antifouling property, it can be used in various applications. For example, it can be used for solar cell protective sheets, agricultural sheets, large building roofing materials, and the like. In particular, when used as a front protective sheet for solar cells, it is possible to suppress a decrease in sunlight reaching the cells due to the adhesion of dirt, and it is possible to maintain power generation efficiency at a high level for a long period of time.

  Next, the present invention will be specifically described with reference to examples and comparative examples. Unless otherwise indicated, “parts” and “%” are weight standards.

(Synthesis Example 1 [Preparation Example of Polysiloxane (a1-1)])
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, a condenser tube and a nitrogen gas inlet is charged with 415 parts of methyltrimethoxysilane (MTMS) and 756 parts of 3-methacryloyloxypropyltrimethoxysilane (MPTS). The temperature was raised to 60 ° C. with stirring under aeration of gas. Next, a mixture consisting of 0.1 part of “A-3” (iso-propyl acid phosphate manufactured by Sakai Chemical Co., Ltd.) and 121 parts of deionized water was added dropwise over 5 minutes. After completion of the dropwise addition, the reaction vessel was heated to 80 ° C. and stirred for 4 hours to carry out a hydrolysis condensation reaction, thereby obtaining a reaction product.
By removing methanol and water contained in the obtained reaction product under conditions of 40 to 60 ° C. under reduced pressure of 1 to 30 kilopascals (kPa), the number average molecular weight is 1000 and the active ingredient is 75. 1000 parts of polysiloxane (a1-1) which is 0.0% was obtained.
The "active ingredient" is a value obtained by dividing the theoretical yield (parts by weight) when all the methoxy groups of the silane monomer used undergo hydrolysis condensation reaction by the actual yield (parts by weight) after hydrolysis condensation reaction, That is, it is calculated by the formula [theoretical yield when all methoxy groups of the silane monomer undergo hydrolysis condensation reaction (parts by weight) / actual yield after hydrolysis condensation reaction (parts by weight)].

(Synthesis Example 2 [Preparation Example of Polysiloxane (a1-2)])
Into a reaction vessel equipped with a stirrer, thermometer, dropping funnel, condenser and nitrogen gas inlet, 415 parts of methyltrimethoxysilane (MTMS) was charged, and the temperature was raised to 60 ° C. while stirring under nitrogen gas. did. Next, a mixture consisting of 0.1 part of “A-3” (iso-propyl acid phosphate manufactured by Sakai Chemical Co., Ltd.) and 121 parts of deionized water was added dropwise over 5 minutes. After completion of the dropwise addition, the reaction vessel was heated to 80 ° C. and stirred for 4 hours to carry out a hydrolysis condensation reaction, thereby obtaining a reaction product.
By removing methanol and water contained in the obtained reaction product under conditions of 40 to 60 ° C. under reduced pressure of 1 to 30 kilopascals (kPa), the number average molecular weight is 1000 and the active ingredient is 75. 1000 parts of polysiloxane (a1-2) which is 0.0% was obtained.

(Synthesis Example 3 [Preparation Example of Vinyl Polymer (a2-1)])
In a reaction vessel similar to Synthesis Example 1, 20.1 parts of phenyltrimethoxysilane (PTMS), 24.4 parts of dimethyldimethoxysilane (DMDMS), and 107.7 parts of n-butyl acetate were charged under a nitrogen gas flow. The temperature was raised to 80 ° C. while stirring. Next, 10 parts of methyl methacrylate (MMA), 1 part of acrylic acid (AA), 1 part of n-butyl acrylate (BA), 3 parts of MPTS, 30 parts of 2-hydroxyethyl methacrylate (HEMA), 20 parts of perfluorohexyl ethyl methacrylate , A mixture containing 15 parts of n-butyl acetate and 15 parts of tert-butylperoxy-2-ethylhexanoate (TBPEH) was stirred into the reaction vessel at the same temperature under aeration of nitrogen gas. It was dripped in 4 hours. After further stirring at the same temperature for 2 hours, a mixture of 0.05 part of “A-3” and 12.8 parts of deionized water was added dropwise to the reaction vessel over 5 minutes, and the mixture was kept at the same temperature for 4 hours. By stirring, the hydrolysis condensation reaction of PTMS, DMDMS, and MPTS was advanced. When the reaction product was analyzed by ¹ H-NMR, almost 100% of the trimethoxysilyl group of the silane monomer in the reaction vessel was hydrolyzed. Subsequently, the vinyl polymer (a2-1) which is a reaction product with a residual amount of TBPEH of 0.1% or less was obtained by stirring at the same temperature for 10 hours.

(Synthesis Example 4 [Preparation Example of Vinyl Polymer (a2-2)])
In a reaction vessel similar to Synthesis Example 1, 20.1 parts of phenyltrimethoxysilane (PTMS), 24.4 parts of dimethyldimethoxysilane (DMDMS), and 107.7 parts of n-butyl acetate were charged under a nitrogen gas flow. The temperature was raised to 80 ° C. while stirring. Next, methyl methacrylate (MMA) 16.42 parts, butyl methacrylate (BMA) 3.18 parts, cyclohexyl methacrylate (CHMA) 60 parts, acrylic acid (AA) 1 part, n-butyl acrylate (BA) 1 part, MPTS 3 Part, 2-hydroxyethyl methacrylate (HEMA) 15.4 parts, n-butyl acetate 15 parts, tert-butylperoxy-2-ethylhexanoate (TBPEH) 15 parts at the same temperature, nitrogen The mixture was added dropwise to the reaction vessel in 4 hours while stirring under aeration of gas. After further stirring at the same temperature for 2 hours, a mixture of 0.05 part of “A-3” and 12.8 parts of deionized water was added dropwise to the reaction vessel over 5 minutes, and the mixture was kept at the same temperature for 4 hours. By stirring, the hydrolysis condensation reaction of PTMS, DMDMS, and MPTS was advanced. When the reaction product was analyzed by ¹ H-NMR, almost 100% of the trimethoxysilyl group of the silane monomer in the reaction vessel was hydrolyzed. Subsequently, by stirring for 10 hours at the same temperature, a vinyl polymer (a2-2) which was a reaction product having a residual amount of TBPEH of 0.1% or less was obtained.

(Synthesis Example 5 [Preparation Example of Vinyl Polymer (a2-3)])
In a reaction vessel similar to Synthesis Example 1, 20.1 parts of phenyltrimethoxysilane (PTMS), 24.4 parts of dimethyldimethoxysilane (DMDMS), and 107.7 parts of n-butyl acetate were charged under a nitrogen gas flow. The temperature was raised to 80 ° C. while stirring. Next, 80.23 parts of methyl methacrylate (MMA), 1 part of acrylic acid (AA), 1 part of n-butyl acrylate (BA), 2.77 parts of acryloxypropyltrimethoxysilane, 2-hydroxyethyl methacrylate (HEMA) 5 A mixture containing 15 parts of n-butyl acetate and 15 parts of tert-butylperoxy-2-ethylhexanoate (TBPEH) in the reaction vessel while stirring at the same temperature under aeration of nitrogen gas. It was dripped in 4 hours. After further stirring at the same temperature for 2 hours, a mixture of 0.05 part of “A-3” and 12.8 parts of deionized water was added dropwise to the reaction vessel over 5 minutes, and the mixture was kept at the same temperature for 4 hours. By stirring, the hydrolysis condensation reaction of PTMS, DMDMS, and MPTS was advanced. When the reaction product was analyzed by ¹ H-NMR, almost 100% of the trimethoxysilyl group of the silane monomer in the reaction vessel was hydrolyzed. Subsequently, by stirring at the same temperature for 10 hours, a vinyl polymer (a2-3) which is a reaction product having a residual amount of TBPEH of 0.1% or less was obtained.

(Synthesis Example 6 [Preparation Example of Vinyl Polymer (a2-4)])
In a reaction vessel similar to Synthesis Example 1, 20.1 parts of phenyltrimethoxysilane (PTMS), 24.4 parts of dimethyldimethoxysilane (DMDMS), and 107.7 parts of n-butyl acetate were charged under a nitrogen gas flow. The temperature was raised to 80 ° C. while stirring. Next, 10 parts of methyl methacrylate (MMA), 29 parts of butyl methacrylate (BMA), 1 part of acrylic acid (AA), 1 part of n-butyl acrylate (BA), 3 parts of MPTS, 30 parts of 2-hydroxyethyl methacrylate (HEMA) , A mixture containing 15 parts of n-butyl acetate and 15 parts of tert-butylperoxy-2-ethylhexanoate (TBPEH) was stirred into the reaction vessel at the same temperature under aeration of nitrogen gas. It was dripped in 4 hours. After further stirring at the same temperature for 2 hours, a mixture of 0.05 part of “A-3” and 12.8 parts of deionized water was added dropwise to the reaction vessel over 5 minutes, and the mixture was kept at the same temperature for 4 hours. By stirring, the hydrolysis condensation reaction of PTMS, DMDMS, and MPTS was advanced. When the reaction product was analyzed by ¹ H-NMR, almost 100% of the trimethoxysilyl group of the silane monomer in the reaction vessel was hydrolyzed. Subsequently, by stirring at the same temperature for 10 hours, a vinyl polymer (a2-4) which is a reaction product having a residual amount of TBPEH of 0.1% or less was obtained.

(Synthesis Example 7 [Preparation Example of Vinyl Polymer (a2-5)])
In a reaction vessel similar to Synthesis Example 1, 20.1 parts of phenyltrimethoxysilane (PTMS), 24.4 parts of dimethyldimethoxysilane (DMDMS), and 107.7 parts of n-butyl acetate were charged under a nitrogen gas flow. The temperature was raised to 80 ° C. while stirring. Next, 70 parts of cyclohexyl methacrylate (CHMA), 1 part of acrylic acid (AA), 1 part of n-butyl acrylate (BA), 3 parts of MPTS, 25 parts of 2-hydroxyethyl methacrylate (HEMA), 15 parts of n-butyl acetate, A mixture containing 15 parts of tert-butylperoxy-2-ethylhexanoate (TBPEH) was dropped into the reaction vessel over 4 hours at the same temperature while stirring under a stream of nitrogen gas. After further stirring at the same temperature for 2 hours, a mixture of 0.05 part of “A-3” and 12.8 parts of deionized water was added dropwise to the reaction vessel over 5 minutes, and the mixture was kept at the same temperature for 4 hours. By stirring, the hydrolysis condensation reaction of PTMS, DMDMS, and MPTS was advanced. When the reaction product was analyzed by ¹ H-NMR, almost 100% of the trimethoxysilyl group of the silane monomer in the reaction vessel was hydrolyzed. Subsequently, by stirring at the same temperature for 10 hours, a vinyl polymer (a2-5) which is a reaction product having a residual amount of TBPEH of 0.1% or less was obtained.

(Synthesis Example 8 [Preparation Example of Composite Resin A-1])
162.5 parts of the polysiloxane (a1-1) obtained in Synthesis Example 1 is added to 307 parts of the vinyl polymer (a2-1) obtained in Synthesis Example 3 and stirred for 5 minutes. 27.5 parts of ionic water was added, and the mixture was stirred at 80 ° C. for 4 hours to carry out a hydrolysis condensation reaction between the reaction product and polysiloxane. The obtained reaction product was distilled under reduced pressure of 10 to 300 kPa under conditions of 40 to 60 ° C. for 2 hours to remove the produced methanol and water, and then 150 parts of methyl ethyl ketone (MEK), n-acetate -Butyl resin 27.3 parts, 600 parts of composite resin (A-1) having a polysiloxane segment (a1-1) and a vinyl polymer segment (a2-1) having a nonvolatile content of 50.0% Got.

(Synthesis Example 9-13)
Other composite resins were synthesized by the same procedure and blending amount. Table 1 shows combinations of polysiloxane and vinyl polymer.

(Synthesis Example 14 [Preparation Example of Composite Resin A-7])
487.5 parts of the polysiloxane (a1-1) obtained in Synthesis Example 1 is added to 307 parts of the vinyl polymer (a2-1) obtained in Synthesis Example 3 and stirred for 5 minutes. 82.5 parts of ionic water was added and the mixture was stirred at 80 ° C. for 4 hours to carry out a hydrolysis condensation reaction between the reaction product and polysiloxane. The obtained reaction product was distilled under reduced pressure of 10 to 300 kPa under conditions of 40 to 60 ° C. for 2 hours to remove the produced methanol and water, and then 150 parts of methyl ethyl ketone (MEK), n-acetate -27.3 parts of butyl are added, and the composite resin (A-7) having a polysiloxane segment (a1-1) and a vinyl polymer segment (a2-1) having a nonvolatile content of 50.0% is obtained. It was.

(Examples 1-8, Comparative Examples 1-6 Preparation Examples of Composition)
According to the composition described in Table 2, the coating compositions for fluororesin moldings of Examples 1 to 8 and the coating compositions for fluororesin moldings of Comparative Examples 1 to 6 were prepared. The units in the table are parts by weight.

In Table 2 and Table 3,
Photoinitiator Hydroxycyclohexyl phenyl ketone polyisocyanate DN-902S [manufactured by DIC Corporation]
Were used respectively.

(Coating on fluoroplastic moldings)
As a fluororesin molding, the coating composition for fluororesin moldings prepared in Examples 1 to 8 and Comparative Examples 1 to 6 was applied to the corona-treated ETFE film (thickness: 200 μm) manufactured by Asahi Glass Co., Ltd. After coating using a coater # 22, the solvent component was removed by heating at 80 ° C. for 4 minutes. A peeling film was placed on the coating surface, and UV was irradiated from the peeling film side under the condition of 1000 mJ / cm ^{2 with} a UV irradiation apparatus F-6100V manufactured by FUSION. Through the curing period, the urethanization reaction in the coating film was advanced to obtain a laminated cured product on which the coating film was formed. Each laminated cured product was designated as GF-1 to GF-8 and NF-1 to NF-6.

Examples 9-18 and Comparative Examples 7-12
For each of the above-described compositions, the following items were evaluated. Summarize each evaluation item and its purpose.
Adhesion test between molded product and coating film Adhesion test after durability test Evaluation of coating film adhesion to adherend Initial and post-durability test Evaluation of antifouling property Whether or not dirt is likely to adhere to the surface Evaluation Long-term weather resistance evaluation Durability evaluation regarding deterioration of coating film itself Antifouling evaluation by comparison of power generation efficiency of solar cell modules As part of the evaluation of antifouling property, power generation efficiency decreases due to contamination on the solar cell light receiving surface We evaluated whether to do.
The details of each evaluation item are described below.

(Adhesion test between molded body and coating film)
Create a grid-like cut (100-square grid) at 1 mm intervals in a 1 cm square area in any part of the obtained laminated cured products GF-1 to GF-8 and NF-1 to NF-6 Then, a cellophane tape was applied to perform a peel test. After the test, the number of squares in which the sealing material is not exposed is determined as adhesion, and when the number of squares is 100-67, ○, when it is 66-34, Δ, when it is 33-0, determined as x did.
(Evaluation of adhesion after endurance test)
Each sample was subjected to a high-temperature and high-humidity test (temperature 120 degrees, humidity 100 RH%, test time 50 hours), and then the adhesion was evaluated by the same technique as the primary adhesion test.
(Evaluation of antifouling properties)
The layered cured products GF-1 to GF-8 and NF-1 to NF-6 were subjected to an outdoor exposure test for 3 months at the exposure site in Takaishi City, DIC Corporation. After the test, the amount of dirt components adhering to the surface of the laminated cured product is visually determined.
◎: Slightly soiled state ○: Slightly soiled state Δ; Stained dirt starts to increase and conspicuously observed ×;
(Long-term weather resistance evaluation)
As an indicator of the long-term weather resistance test, an accelerated weather resistance test (3000 hours) with a sunshine weatherometer of the laminated cured products GF-1 to GF-8 and NF-1 to NF-6 was conducted, and appearance before and after the test Changes were observed. The test conditions are as follows.
JIS L0891 compliant B method Light irradiation Sunshine carbon arc lamp continuous irradiation Temperature 63 ° C
Relative humidity 50%
Rain period and time 60 minutes Irradiation for 12 minutes During the irradiation, long-term weather resistance was evaluated by evaluating the characteristics of the appearance of rainfall according to the following criteria.
5; No change 4; State 3 in which hair cracks (thin cracks) are scattered 3; State 2 in which cracks having a width of 1 mm or more are observed; State 1 in which the coating film is partially peeled and missing 1; Most of the coating film Missing state

Examples 19-26, Comparative Examples 13-18
(Production of back straight type solar cell module)
A hot plate of a laminating apparatus (manufactured by Nisshinbo Mechatronics Co., Ltd.) is adjusted to 150 ° C., and on the hot plate, a stainless steel plate, the solar cell encapsulant, a polycrystalline silicon solar cell, and the solar cell encapsulant The laminated cured products (GF-1) to (GF-8) and (NF-1) to (NF-6) produced in the examples and comparative examples as protective sheets for solar cells are laminated in this order, and the lid of the laminating apparatus In the closed state, 3 minutes of degassing and 8 minutes of pressing are performed in order, and then held for 10 minutes and then removed, and the back straight type solar cell modules (BM-1) to (BM-8), (NBM-1) To (NBM-6).

(Method for measuring power generation efficiency of solar cell module)
Back straight type solar cell modules (BM-1) to (BM-8), (NBM-1) to (NBM-6) obtained above, and an ETFE film not coated with the coating composition of the present invention Using each of the back straight type solar cell modules (NBM-7) obtained by using a solar simulator manufactured by Wacom Denso, the module temperature is 25 ° C., the radiation intensity is 1 kW / m ² , and the spectral distribution is AM1.5G. Then, the power generation efficiency was measured.
(Anti-fouling evaluation by comparison of power generation efficiency of solar cell modules)
In order to compare the degree of decrease in power generation efficiency of the solar cell module due to dirt adhered to the surface, back straight type solar cell modules (BM-1) to (BM-8), (NBM-1) to (NBM-7) Was installed in an outdoor exposure field of Sakai Factory (1-3 Takasago City, Osaka Prefecture), and left as it was for 6 months, and then the power generation efficiency of the solar cell module was measured again by the method described above. The initial measurement value and the measurement value after outdoor exposure were compared to determine the power generation efficiency retention ratio, that is, (post-exposure measurement value) / (initial measurement value).

比較例７においては、フッ素樹脂成形体表面に対する密着性が発現しなかった。
比較例８においては、密着性の耐久性が得られず、かつ屋外に設置した太陽電池モジュール表面の汚れ付着が多く、発電効率も低下した。
比較例９−１２においては、短期間での太陽電池モジュール表面の汚れ付着はそれほど多くなかったものの、塗膜の長期耐候性が得られず、長期間での屋外での使用に適しているとは言えないものであった。
比較例１３においては、太陽電池モジュール表面の汚れ付着が多く、発電効率も低下した。

In Comparative Example 7, adhesion to the surface of the fluororesin molded body was not expressed.
In Comparative Example 8, the durability of adhesion could not be obtained, and the surface of the solar cell module installed outdoors was often contaminated, resulting in a decrease in power generation efficiency.
In Comparative Example 9-12, although there was not much dirt adhesion on the surface of the solar cell module in a short period, the long-term weather resistance of the coating film was not obtained, and it was suitable for outdoor use over a long period of time. It couldn't be said.
In Comparative Example 13, there was much dirt adhesion on the surface of the solar cell module, and the power generation efficiency was also lowered.

  The curable coating composition for fluororesin moldings of the present invention is suitably used as a coating for fluororesin moldings because it adheres well to fluororesin moldings and has excellent antifouling properties and long-term weather resistance. The laminated cured product obtained by applying to a fluororesin molded body can be suitably used for various applications, and can be particularly suitably used as a protective sheet for a solar cell module.

Claims (8)

A polysiloxane segment (a1) having a structural unit represented by the general formula (1) and / or the general formula (2), a silanol group and / or a hydrolyzable silyl group, and a vinyl heavy polymer having an alcoholic hydroxyl group. The coalesced segment (a2) is a curable coating composition for a fluororesin molded article containing a composite resin (A) bonded by a bond represented by the general formula (3) and a polyisocyanate (B), The content of the polysiloxane segment (a1) is 10 to 60% by weight with respect to the total solid content of the curable coating composition for a fluororesin molded body, and the content of polyisocyanate (B) is the fluorine. It is 5 to 50% by weight based on the total solid content of the curable coating composition for resin molded bodies,
A curable coating composition for fluororesin moldings.

(1)

(2)
(In the general formulas (1) and (2), R ¹ , R ² and R ³ are each independently -R ⁴ -CH = CH ₂ , -R ⁴ -C (CH ₃ ) = CH ₂ ,- A group having one polymerizable double bond selected from the group consisting of R ⁴ —O—CO—C (CH ₃ ) ═CH ₂ and —R ⁴ —O—CO—CH═CH ₂ (provided that R ⁴ Represents a single bond or an alkylene group having 1 to 6 carbon atoms.), An alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group, or 7 carbon atoms. Represents an aralkyl group of ˜12)

(3)
(In the general formula (3), carbon atoms constitute a part of the vinyl polymer segment (a2), and silicon atoms bonded only to oxygen atoms constitute a part of the polysiloxane segment (a1). To do) The curable coating composition for a fluororesin molded body according to claim 1, wherein the composite resin (A) has a hydroxyl value of 50 mgKOH / g or less. The curable coating composition for a fluororesin molded body according to claim 1 or 2, wherein the composite resin (A) further contains a fluorine atom. Furthermore, the curable coating composition for fluororesin molded bodies according to any one of claims 1 to 3, further comprising a fluorine atom-containing reactive compound (C). A laminated cured product obtained by applying and curing the curable composition for a fluororesin molded body according to claim 1 to a fluororesin molded body. The laminated cured product according to claim 5, wherein the fluororesin molded body is in a sheet form. The protection sheet for solar cells which has the lamination | stacking hardened | cured material of Claim 6. A solar cell module comprising the solar cell protective sheet according to claim 7.