JP5708740B2 - Coating composition, cured coating film, solar cell module backsheet, and solar cell module - Google Patents

Description

The present invention relates to a coating composition, a cured coating film, a back sheet of a solar cell module, and a solar cell module.

A solar battery module is usually composed of a solar battery cell, a sealing material for sealing the solar battery cell, a surface layer and a back sheet provided on the light receiving surface side (front surface side) and the back surface side of the sealing material, respectively. Composed. Solar cell modules are used in harsh environments, such as outdoors, in terms of temperature and humidity. For this reason, high weather resistance, moisture resistance, heat resistance and ultraviolet resistance are required.

As a back sheet for a solar cell module, a sheet in which a fluororesin layer is formed on a substrate is known from the viewpoints of weather resistance, wet heat resistance, flame retardancy, and the like (Patent Document 1).
Such a fluororesin layer is also formed by applying a coating composition containing a fluorine-containing polymer, a pigment, an organic solvent, etc. on a substrate and curing it (Patent Document 2).

In addition, solar cell modules are often installed on the roofs of buildings, and are required to be difficult to burn in order to prevent the spread of fire in the event of a fire.

As a method for improving the flame retardancy of the back sheet of the solar cell module, it is known to add a flame retardant to the fluororesin layer.
Patent Document 3 discloses a coating composition containing a fluororesin, an inorganic pigment, and a flame retardant, wherein the flame retardant is a melamine cyanurate, a guanidine compound, a triazine compound, a hindered amine compound, an aromatic phosphate ester, It is disclosed that it is 1 or more types chosen from aromatic condensed phosphate ester and a hydrated metal compound.

JP 2008-227203 A JP 2010-238760 A JP 2011-162598 A

However, in recent years, the demand for flame retardancy required for backsheets has become stricter, and the flame retardancy of conventional solar cell module backsheets is still insufficient, and improvements have been made.
In view of the present situation, an object of the present invention is to provide a coating composition that can produce a cured coating film having excellent flame retardancy and a back sheet of a solar cell module.

The present invention is a coating composition containing a curable functional group-containing fluorine-containing polymer, a flame retardant, and an organic solvent.
The flame retardant is preferably one that generates non-combustible gas at the early stage of combustion and exhibits flame retardancy by diluting the combustible gas and / or blocking oxygen.
The flame retardant is preferably at least one selected from the group consisting of a compound containing Group 15 of the periodic table and a compound containing a halogen element of Group 17 of the periodic table .
The flame retardant is preferably a phosphorus nitrogen-containing composition (A) or a mixture (B) of a bromine-containing compound and an antimony-containing compound.
The phosphorus nitrogen-containing composition (A) is preferably a mixture of piperazine pyrophosphate and melamine cyanurate.
In the mixture (B) of the bromine-containing compound and the antimony-containing compound, the bromine-containing compound is decabromodiphenyl oxide, 1,2-bis (2,3,4,5,6-pentabromophenyl) ethane, tris (Tribromophenoxy) triazine, ethylenebistetrabromophthalimide, polybromophenylindane, brominated phenylene oxide, and at least one selected from the group consisting of polypentabromobenzyl acrylate, and the antimony-containing compound is Antimony trioxide is preferred.
In the mixture (B) of the bromine-containing compound and the antimony-containing compound, the bromine-containing compound is 1,2-bis (2,3,4,5,6-pentabromophenyl) ethane, and the antimony-containing compound Is preferably antimony trioxide.
It is preferable that content of the said flame retardant is 1-45 mass parts with respect to 100 mass parts of curable functional group containing fluorine-containing polymers.
The curable functional group-containing fluorine-containing polymer includes a polymer unit based on a fluorine-containing monomer, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an acid anhydride monomer, an amino group-containing monomer, and And a polymerized unit based on at least one curable functional group-containing monomer selected from the group consisting of silicone-based vinyl monomers.
The fluorine-containing monomer is preferably at least one selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, and vinylidene fluoride.
The coating composition of the present invention is preferably a coating agent for a back sheet of a solar cell module.
The present invention is also a cured coating film formed using the coating composition described above.
The present invention also includes a base material and a fluororesin layer on at least one surface of the base material, and the fluororesin layer is a cured coating film formed using the above-described coating composition. It is also the back sheet of the solar cell module that is characterized.
The present invention is also a solar cell module comprising the back sheet of the solar cell module described above.

If the coating composition of this invention is used, the cured coating film excellent in the flame retardance and the back sheet | seat of a solar cell module can be formed.

FIG. 1 is a schematic diagram of an example of the solar cell module of the present invention. FIG. 2 is a schematic diagram of an example of the solar cell module of the present invention.

The present invention is described in detail below.

The present invention is a coating composition comprising a curable functional group-containing fluorine-containing polymer, a flame retardant, and an organic solvent. For this reason, the coating film which has the outstanding flame retardance can be formed.

The flame retardant used in the coating composition of the present invention preferably generates a non-combustible gas at the initial stage of combustion and exhibits flame retardancy by diluting the combustible gas and / or blocking oxygen.

The flame retardant is preferably at least one selected from the group consisting of compounds containing Group 15 of the periodic table and compounds containing halogen elements of Group 17 of the periodic table .

Examples of the compound containing a halogen element of Group 17 of the periodic table include aliphatic, alicyclic, and aromatic organic halogen compounds such as bromine-based tetrabromobisphenol A (TBA), decabromodiphenyl ether (DBDPE), and octabromodiphenyl ether (OBDPE). ), TBA epoxy / phenoxy oligomer, brominated cross-linked polystyrene, chlorinated chlorinated paraffin, perchlorocyclopentadecane and the like.
Examples of the compound containing Group 15 of the periodic table include phosphoric acid esters and polyphosphates as phosphorus compounds. The antimony compound is preferably used in combination with a halogen compound, and examples thereof include antimony trioxide and antimony pentoxide. In addition, aluminum hydroxide, magnesium hydroxide, and molybdenum trioxide can also be used.
These flame retardants can be arbitrarily selected from at least one kind and a blending amount according to the kind of the curable functional group-containing fluorine-containing polymer, but are not limited thereto.

Specifically, the flame retardant is more preferably a phosphorus nitrogen-containing composition (A) or a mixture (B) of a bromine-containing compound and an antimony-containing compound. By combining these flame retardants with a curable functional group fluorine-containing polymer, high flame retardancy is exhibited.

The phosphorus nitrogen-containing composition (A) is preferably a mixture of piperazine pyrophosphate and melamine cyanurate.
Examples of the piperazine pyrophosphate include those disclosed in JP-A-48-087991 and US Pat. No. 4,599,375.
Examples of the melamine cyanurate include powdered reaction products of melamine and cyanuric acid. The reaction product of melamine and cyanuric acid has a large amount of nitrogen atoms in its structure, and when exposed to a high temperature of about 350 ° C. or higher, it generates nitrogen gas and inhibits combustion.
The phosphorus nitrogen-containing composition (A) preferably has a mass ratio of melamine cyanurate to the piperazine pyrophosphate of 0.014 to 3.000. When the melamine cyanurate is in the above range, the flame retardancy is improved and the blocking property of the coating film is also improved. The mass ratio of melamine cyanurate to the piperazine pyrophosphate is more preferably 0.04 or more, further preferably 0.1 or more, more preferably 1.4 or less, and further preferably 0.5 or less in the mixture.

Examples of commercially available products that can be used as the phosphorus nitrogen-containing composition (A) include SCFR-200 (manufactured by Sakai Chemical Industry Co., Ltd.) and SCFR-110 (manufactured by Sakai Chemical Industry Co., Ltd.).

The bromine-containing compound is preferably an aromatic compound having a bromine content of 65% or higher, a melting point of 200 ° C. or higher, and a 5% decomposition temperature of 340 ° C. or higher.
Specifically, the bromine-containing compound includes decabromodiphenyl oxide, 1,2-bis (2,3,4,5,6-pentabromophenyl) ethane, tris (tribromophenoxy) triazine, ethylenebistetrabromo. At least one selected from the group consisting of phthalimide, polybromophenylindane, brominated phenylene oxide, and polypentabromobenzyl acrylate is preferable.

Among them, 1,2-bis (2,3,4,5,6-pentabromo represented by the formula (a) is high in that it has a high melting point and does not melt or bleed out even when the coating film is heated and cured. More preferred is phenyl) ethane.

A commercially available product may be used as the bromine-containing compound, and examples thereof include SAYTEX 8010 (manufactured by Albemarle).

Examples of the antimony-containing compound include antimony oxides such as antimony trioxide and antimony pentoxide. Of these, antimony trioxide is preferable because it can be obtained at low cost.

It is preferable that the mixture (B) of the bromine-containing compound and the antimony-containing compound contains 50 to 90% by mass of the bromine-containing compound in the mixture. When the content of the bromine-containing compound is in the above range, an improvement in flame retardancy can be expected due to a synergistic effect with antimony oxide. The content of the bromine-containing compound is more preferably 55% by mass or more, further preferably 60% by mass or more, more preferably 85% by mass or less, and still more preferably 80% by mass or less in the mixture.

It is preferable that content of a flame retardant is 1-45 mass parts with respect to 100 mass parts of curable functional group containing fluorine-containing polymers. When the content of the flame retardant is in the above range, good dispersibility in the paint and improvement in the flame retardance of the coating film can be expected. If the content of the flame retardant is less than 1 part by mass, the flame retardancy may not be improved, and if it exceeds 45 parts by mass, it may be difficult to maintain the physical properties of the paint or coating film.
The content of the flame retardant is more preferably 30 parts by mass or less, further preferably 20 parts by mass or less, and particularly preferably 15 parts by mass or less with respect to 100 parts by mass of the curable functional group-containing fluoropolymer. Moreover, 3 mass parts or more are more preferable, and 5 mass parts or more are still more preferable.

When a flame retardant is the said phosphorus nitrogen containing composition (A), it is preferable that the content is 8-19 mass parts with respect to 100 mass parts of curable functional group containing fluorine-containing polymers. The content of the phosphorus nitrogen-containing composition (A) is more preferably 9 parts by mass or more, further preferably 10 parts by mass or more, and more preferably 17 parts by mass or less with respect to 100 parts by mass of the curable functional group-containing fluorine-containing polymer. Preferably, 15 parts by mass or less is more preferable.

When the flame retardant is a mixture (B) of the bromine-containing compound and the antimony-containing compound, the content of bromide-containing compound is 1 with respect to 100 parts by mass of the curable functional group-containing fluorine-containing polymer. It is preferable that it is -30 mass parts, and it is preferable that content of an antimony containing compound is 0.5-15 mass parts.
The content of the bromine-containing compound is more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, and more preferably 20 parts by mass or less, with respect to 100 parts by mass of the curable functional group-containing fluoropolymer. Part or less is more preferable.
The content of the antimony compound is more preferably 1.5 parts by mass or more, further preferably 2.5 parts by mass or more, and more preferably 10 parts by mass or less with respect to 100 parts by mass of the curable functional group-containing fluoropolymer. 7.5 parts by mass or less is more preferable.

The coating composition of the present invention contains a curable functional group-containing fluorine-containing polymer. By including the curable functional group-containing fluorine-containing polymer, a coating film excellent in weather resistance, moisture resistance, heat resistance and insulation can be formed.

As said curable functional group containing fluorine-containing polymer, the polymer which introduce | transduced the curable functional group into the fluorine-containing polymer is mentioned. The fluorine-containing polymer includes a resinous polymer having a clear melting point, an elastomeric polymer exhibiting rubber elasticity, and an intermediate thermoplastic elastomeric polymer.

Examples of the functional group that imparts curability to the fluoropolymer include, for example, a hydroxyl group (excluding a hydroxyl group contained in a carboxyl group; the same applies hereinafter), a carboxyl group, a group represented by —COOCO—, an amino group, and a glycidyl group. , A silyl group, a silanate group, an isocyanate group, and the like, which are appropriately selected according to the ease of production of the polymer and the curing system. Among these, a hydroxyl group, a carboxyl group, a group represented by —COOCO—, an amino group, and a silyl group are preferable from the viewpoint of good curing reactivity, and particularly a hydroxyl group from the viewpoint of easy availability of the polymer and good reactivity. Is preferred. These curable functional groups are usually introduced into the fluorinated polymer by copolymerizing a fluorinated monomer and a curable functional group-containing monomer.

Examples of the curable functional group-containing monomer include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an acid anhydride monomer, an amino group-containing monomer, and a silicone vinyl monomer. 1 type, or 2 or more types of these can be used.
The curable functional group-containing fluorine-containing polymer includes a polymer unit based on a fluorine-containing monomer, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an acid anhydride monomer, an amino group-containing monomer, and And a polymer unit based on at least one curable functional group-containing monomer selected from the group consisting of silicone-based vinyl monomers, from a hydroxyl group-containing monomer and a carboxyl group-containing monomer. More preferably, it contains a polymerized unit based on at least one curable functional group-containing monomer selected from the group consisting of:

Examples of the curable functional group-containing monomer include, but are not limited to, the following. In addition, these 1 type (s) or 2 or more types can be used.

(1-1) Hydroxyl group-containing monomer:
Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxy-2-methyl. Hydroxyl-containing vinyl ethers such as butyl vinyl ether, 5-hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether; hydroxyl-containing allyl ethers such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether and glycerol monoallyl ether . Among these, hydroxyl group-containing vinyl ethers, particularly 4-hydroxybutyl vinyl ether and 2-hydroxyethyl vinyl ether, are preferable in that they have excellent polymerization reactivity and functional group curability.

Examples of other hydroxyl group-containing monomers include hydroxyalkyl esters of (meth) acrylic acid such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.
In addition, the carboxyl group-containing monomer described later is not included in the hydroxyl group-containing monomer.

(1-2) Carboxyl group-containing monomer:
Examples of the carboxyl group-containing monomer include the general formula (1):

(Wherein R ¹ , R ² and R ³ are the same or different and all are hydrogen atoms, alkyl groups, aryl groups, carboxyl groups or alkoxycarbonyl groups; n is 0 or 1) Unsaturated carboxylic acids such as carboxylic acids, unsaturated dicarboxylic acids, monoesters thereof; or general formula (2):

(Wherein R ⁴ and R ⁵ are the same or different and both are saturated or unsaturated linear or cyclic alkyl groups; n is 0 or 1; m is 0 or 1) And monomers.

Specific examples of the unsaturated carboxylic acids represented by the general formula (1) include, for example, acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, cinnamic acid, itaconic acid, itaconic acid monoester, maleic acid, and maleic acid monoester. Examples include esters, fumaric acid, and fumaric acid monoesters. Among these, crotonic acid, itaconic acid, maleic acid, maleic acid monoester, fumaric acid, and fumaric acid monoester are preferable because they are low in homopolymerization and difficult to form a homopolymer.

Specific examples of the carboxyl group-containing vinyl ether monomer represented by the general formula (2) include, for example, 3-allyloxypropionic acid, 3- (2-allyloxyethoxycarbonyl) propionic acid, 3- (2-ary One type or two or more types such as roxybutoxycarbonyl) propionic acid, 3- (2-vinyloxyethoxycarbonyl) propionic acid, 3- (2-vinyloxybutoxycarbonyl) propionic acid and the like can be mentioned. Among these, 3- (2-allyloxyethoxycarbonyl) propionic acid is advantageous and preferable in terms of good monomer stability and polymerization reactivity.

As the carboxyl group-containing monomer, in addition to those represented by the general formula (1) or (2), for example, alkenyl esters of polybasic carboxylic acids such as vinyl phthalate and vinyl pyromellitic acid Can be used.

(1-3) Acid anhydride monomer:
Examples of the acid anhydride monomer include unsaturated dicarboxylic acid anhydrides such as maleic acid anhydride.

(1-4) Amino group-containing monomer:
Examples of the amino group-containing monomer include amino vinyl ethers represented by CH ₂ ═CH—O— (CH ₂ ) _x —NH ₂ (x = 0 to 10); CH ₂ ═CH—O—CO (CH ₂ ) amines represented by _{x -NH 2 (x = 1~10)} ; other aminomethylstyrene, vinylamine, acrylamide, vinylacetamide, vinylformamide or the like.

(1-5) Silicone vinyl monomer:
Examples of the silicone-based vinyl monomer include CH ₂ ═CHCO ₂ (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , CH ₂ ═CHCO ₂ (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , and CH ₂ ═C. _{(CH 3) CO 2 (CH} 2) 3 Si (OCH 3) 3, CH 2 = C (CH 3) CO 2 (CH 2) 3 Si (OC 2 H 5) 3, CH 2 = CHCO 2 (CH 2 _{) 3 SiCH 3 (OC 2 H} 5) 2, CH 2 = C (CH 3) CO 2 (CH 2) 3 SiC 2 H 5 (OCH 3) 2, CH 2 = C (CH 3) CO 2 (CH 2 ) ₃ Si (CH ₃ ) ₂ (OC ₂ H ₅ ), CH ₂ ═C (CH ₃ ) CO ₂ (CH ₂ ) ₃ Si (CH ₃ ) ₂ OH, CH ₂ ═CH (CH ₂ ) ₃ Si (OCOCH) _{3) 3, CH 2 = C} (C _{3) CO 2 (CH 2)} 3 SiC 2 H 5 (OCOCH 3) 2, CH 2 = C (CH 3) CO 2 (CH 2) 3 SiCH 3 (N (CH 3) COCH 3) 2, CH 2 = _{CHCO 2 (CH 2) 3 SiCH} 3 _{[ON (CH 3) C 2 H} 5 ] _{2, CH 2 = C (CH} 3) CO 2 (CH 2) 3 SiC 6 H 5 _[ON (CH _{3) C} 2 H _{5] 2,} etc. (meth) acrylic acid _{esters; CH 2 = CHSi [ON =} C (CH 3) (C 2 H 5)] 3, CH 2 = CHSi (OCH 3) 3, CH 2 = CHSi (OC ₂ H ₅ ) ₃ , CH ₂ = CHSiCH ₃ (OCH ₃ ) ₂ , CH ₂ = CHSi (OCOCH ₃ ) ₃ , CH ₂ = CHSi (CH ₃ ) ₂ (OC ₂ H ₅ ), CH ₂ = CHSi (CH ₃ ) _{2 iCH 3 (OCH 3) 2,} CH 2 = CHSiC 2 H 5 (OCOCH 3) 2, CH 2 = CHSiCH 3 _{[ON (CH 3) C 2 H} 5 ] _2, vinyl trichlorosilane or their partial hydrolysates And vinyl silanes such as trimethoxysilylethyl vinyl ether, triethoxysilylethyl vinyl ether, trimethoxysilylbutyl vinyl ether, methyldimethoxysilylethyl vinyl ether, trimethoxysilylpropyl vinyl ether, and triethoxysilylpropyl vinyl ether.

As the fluorine-containing monomer, that is, a monomer for forming a fluorine-containing polymer into which a curable functional group is introduced, for example, tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, and , Fluorovinyl ether can be mentioned, and one or more of these can be used.
Among these, at least one selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, and vinylidene fluoride is preferable, and tetrafluoroethylene is more preferable.

Examples of the fluorine-containing polymer into which the curable functional group is introduced may include the following, depending on the polymer units constituting the polymer.

(1) Perfluoroolefin polymer mainly composed of perfluoroolefin units:
Specific examples include a homopolymer of tetrafluoroethylene (TFE), a copolymer of TFE and hexafluoropropylene (HFP), perfluoro (alkyl vinyl ether) (PAVE), and the like, and further copolymerizable therewith. And copolymers with other monomers.

Examples of the other copolymerizable monomers include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatate, vinyl laurate, vinyl stearate, cyclohexyl carboxyl. Carboxylic acid vinyl esters such as vinyl acid vinyl, vinyl benzoate, para-t-butyl vinyl benzoate; alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether; ethylene, propylene, n-butene, isobutene, etc. Non-fluorinated olefins such as vinylidene fluoride (VdF), chlorotrifluoroethylene (CTFE), vinyl fluoride (VF), fluorovinyl ether, and other fluorine-based monomers. The present invention is not limited to only from.

Among these, TFE-based polymers mainly composed of TFE are preferable in terms of excellent pigment dispersibility, weather resistance, copolymerization, and chemical resistance.

Specific examples of the curable functional group-containing perfluoroolefin-based polymer include, for example, a copolymer of TFE / isobutylene / hydroxybutyl vinyl ether / other monomers, TFE / vinyl versatate / hydroxybutyl vinyl ether / other monomers. Copolymer, TFE / VdF / hydroxybutyl vinyl ether / other monomer copolymer, etc., especially TFE / isobutylene / hydroxybutyl vinyl ether / other monomer copolymer, TFE / versaic acid Vinyl / hydroxybutyl vinyl ether / other monomer copolymers are preferred.

Examples of the TFE-based curable polymer composition for paint include Zeffle GK series manufactured by Daikin Industries, Ltd.

(2) CTFE polymer mainly composed of chlorotrifluoroethylene (CTFE) unit:
Specific examples include a copolymer of CTFE / hydroxybutyl vinyl ether / other monomers.

Examples of the CTFE-based curable polymer composition for paint include Lumiflon manufactured by Asahi Glass Co., Ltd., Fluoronate manufactured by DIC Co., Ltd., Cefral Coat manufactured by Central Glass Co., Ltd., and ZAFLON manufactured by Toa Gosei Co., Ltd. it can.

(3) VdF polymers mainly composed of vinylidene fluoride (VdF) units:
Specific examples include VdF / TFE / hydroxybutyl vinyl ether / a copolymer of other monomers.

(4) Fluoroalkyl group-containing polymer mainly composed of fluoroalkyl units:
Specific examples include CF ₃ CF ₂ (CF ₂ CF ₂ ) _n CH ₂ CH ₂ OCOCH═CH ₂ (mixture of n = 3 and 4) / 2-hydroxyethyl methacrylate / stearyl acrylate copolymer. .

Examples of the fluoroalkyl group-containing polymer include Unidyne and Ftone manufactured by Daikin Industries, Ltd., and Zonyl manufactured by DuPont.

Among these, in consideration of weather resistance and moisture resistance, perfluoroolefin-based polymers are preferable.

The said curable functional group containing fluorine-containing polymer can be manufactured by the method disclosed by Unexamined-Japanese-Patent No. 2004-204205, for example.

It is preferable that content of the said curable functional group containing fluorine-containing polymer in the coating composition of this invention is 20-90 mass% with respect to 100 mass% of total amounts of the non volatile matter in a coating composition.

Examples of the organic solvent in the coating composition of the present invention include esters such as ethyl acetate, butyl acetate, isopropyl acetate, isobutyl acetate, cellosolve acetate, and propylene glycol methyl ether acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like. Ketones; Cyclic ethers such as tetrahydrofuran and dioxane; Amides such as N, N-dimethylformamide and N, N-dimethylacetamide; Aromatic hydrocarbons such as xylene, toluene and solvent naphtha; Propylene glycol methyl ether and ethyl Glycol ethers such as cellosolve; diethylene glycol esters such as carbitol acetate; n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, - undecane, n- dodecane, aliphatic hydrocarbons such as mineral spirits; these mixtures, and the like.
These may be used alone or in combination of two or more.
Of these, esters are preferable, and butyl acetate is particularly preferable.

The coating composition of the present invention preferably contains a curing agent. By containing a curing agent, a cured coating film can be formed using the coating composition of the present invention.
The curing agent is selected according to the functional group of the curable polymer. For example, for a hydroxyl group-containing fluoropolymer, an isocyanate curing agent, a melamine resin, a silicate compound, an isocyanate group-containing silane compound can be preferably exemplified. . In addition, amino-based curing agents and epoxy-based curing agents are used for carboxyl group-containing fluorine-containing polymers, and carbonyl-group-containing curing agents, epoxy-based curing agents, acid anhydride-based curing agents are used for amino group-containing fluorine-containing polymers. Is usually adopted.

As the curing agent, among them, a polyisocyanate compound derived from at least one isocyanate selected from the group consisting of xylylene diisocyanate (XDI) and bis (isocyanate methyl) cyclohexane (hydrogenated XDI, H6XDI), hexamethylene At least one compound selected from the group consisting of blocked isocyanate compounds based on diisocyanate (HDI), polyisocyanate compounds derived from hexamethylene diisocyanate (HDI), and polyisocyanate compounds derived from isophorone diisocyanate (IPDI) Is preferred.

The curing agent is derived from at least one isocyanate selected from the group consisting of xylylene diisocyanate (XDI) and bis (isocyanatomethyl) cyclohexane (hydrogenated XDI, H6XDI) (hereinafter also referred to as isocyanate (i)). When the polyisocyanate compound (hereinafter also referred to as polyisocyanate compound (I)) is used, the adhesion between the cured coating film obtained from the coating composition of the present invention and the encapsulant of the solar cell module is more excellent. It becomes a thing. Furthermore, the back sheet of the solar cell module having the cured coating film is more excellent in blocking resistance to the surface with which the cured coating film comes into contact in a winding process or the like.
Examples of the polyisocyanate compound (I) include an adduct obtained by addition polymerization of the isocyanate (i) and a trihydric or higher aliphatic polyhydric alcohol, and an isocyanurate structure (nurate) comprising the isocyanate (i). And a biuret composed of the above-mentioned isocyanate (i).

As the adduct, for example, the following general formula (3):

(In the formula, R ⁶ represents an aliphatic hydrocarbon group having 3 to 20 carbon atoms. R ⁷ represents a phenylene group or a cyclohexylene group. K is an integer of 3 to 20). Those having the following structure are preferred.
R ⁶ in the general formula (3) is a hydrocarbon group based on the trivalent or higher aliphatic polyhydric alcohol, more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and 3 to 6 carbon atoms. The aliphatic hydrocarbon group is more preferable.
When R ⁷ is a phenylene group, a 1,2-phenylene group (o-phenylene group), a 1,3-phenylene group (m-phenylene group), and a 1,4-phenylene group (p-phenylene group) Any of these may be used. Of these, a 1,3-phenylene group (m-phenylene group) is preferable. Moreover, all R < ⁷ > in the said General formula (3) may be the same phenylene group, and 2 or more types may be mixed.
When R ⁷ is a cyclohexylene group, it may be any of 1,2-cyclohexylene group, 1,3-cyclohexylene group, and 1,4-cyclohexylene group. Of these, a 1,3-cyclohexylene group is preferable. Moreover, all R < ⁷ > in the said General formula (3) may be the same cyclohexylene group, and 2 or more types may be mixed.
The k is a number corresponding to the valence of a trihydric or higher aliphatic polyhydric alcohol. As said k, More preferably, it is an integer of 3-10, More preferably, it is an integer of 3-6.

The isocyanurate structure has the following general formula (4) in the molecule:

It has 1 or 2 or more isocyanurate rings.
Examples of the isocyanurate structure include a trimer obtained by the trimerization reaction of the isocyanate, a pentamer obtained by the pentamerization reaction, and a heptamer obtained by the heptamization reaction.
Among them, the following general formula (5):

(Wherein, R ⁷ has the general formula (3) is the same as R ⁷ in.) Trimer is preferably represented by. That is, the isocyanurate structure is preferably a trimer of at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis (isocyanatomethyl) cyclohexane.

The biuret is represented by the following general formula (6):

(Wherein, R ⁷ has the general formula (3) is the same as R ⁷ in.) Is a compound having a structure represented by, under different conditions than the case of obtaining the isocyanurate structure, the It can be obtained by trimerizing isocyanate.

The polyisocyanate compound (I) includes, among others, at least one isocyanate selected from the group consisting of the above adducts, that is, xylylene diisocyanate and bis (isocyanatomethyl) cyclohexane, and a trihydric or higher aliphatic polyhydric alcohol. Are preferably obtained by addition polymerization.

When the polyisocyanate compound (I) is an adduct of the isocyanate (i) and a trihydric or higher aliphatic polyhydric alcohol, the trihydric or higher aliphatic polyhydric alcohol is specifically glycerol. , Trimethylolpropane (TMP), 1,2,6-hexanetriol, trimethylolethane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,1,1-tris (bishydroxymethyl) propane, 2,2 -Trihydric alcohols such as bis (hydroxymethyl) butanol-3; tetrahydric alcohols such as pentaerythritol and diglycerol; pentahydric alcohols such as arabit, ribitol, and xylitol (pentit); sorbitol, mannitol, galactitol, allozulcit, etc. Such as hexahydric alcohol (hexit) That. Of these, trimethylolpropane and pentaerythritol are particularly preferable.

Moreover, as xylylene diisocyanate (XDI) used as a component of the adduct, 1,3-xylylene diisocyanate (m-xylylene diisocyanate), 1,2-xylylene diisocyanate (o-xylylene diisocyanate), 1 1,4-xylylene diisocyanate (p-xylylene diisocyanate), among which 1,3-xylylene diisocyanate (m-xylylene diisocyanate) is preferable.

The bis (isocyanatemethyl) cyclohexane (hydrogenated XDI, H6XDI) used as a component of the adduct is 1,3-bis (isocyanatemethyl) cyclohexane, 1,2-bis (isocyanatemethyl) cyclohexane, 1, 4-bis (isocyanatomethyl) cyclohexane can be mentioned, among which 1,3-bis (isocyanatemethyl) cyclohexane is preferred.

Suitable in the present invention by addition polymerization of at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis (isocyanatomethyl) cyclohexane and an aliphatic polyhydric alcohol having 3 or more valences as described above. Adducts used in the above are obtained.

As an adduct preferably used in the present invention, specifically, for example, the following general formula (7):

(Wherein R ⁸ represents a phenylene group or a cyclohexylene group), that is, at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis (isocyanatomethyl) cyclohexane; Examples thereof include polyisocyanate compounds obtained by addition polymerization with methylolpropane (TMP).
The phenylene group or cyclohexylene group represented by R ⁸ in the general formula (7) is as described for R ⁷ in the general formula (3).

Commercially available products of the polyisocyanate compound represented by the general formula (7) include Takenate D110N (manufactured by Mitsui Chemicals, XDI and TMP adduct, NCO content 11.8%), Takenate D120N (Mitsui Chemicals) The product made from a company, the adduct of H6XDI and TMP, NCO content 11.0%), etc. are mentioned.

Specific examples of the polyisocyanate compound (I) having an isocyanurate structure include Takenate D121N (Mitsui Chemicals, H6XDI Nurate, NCO content 14.0%), Takenate D127N (Mitsui Chemicals, Inc.) H6XDI nurate, H6XDI trimer, NCO content 13.5%) and the like.

By using a blocked isocyanate based on hexamethylene diisocyanate (HDI) as a curing agent (hereinafter also simply referred to as a blocked isocyanate), the coating composition of the present invention has a sufficient pot life (pot life). .
As the blocked isocyanate, those obtained by reacting a polyisocyanate compound derived from hexamethylene diisocyanate (hereinafter also referred to as polyisocyanate compound (II)) with a blocking agent are preferable.
As the polyisocyanate compound (II), for example, an adduct obtained by addition polymerization of hexamethylene diisocyanate and a trihydric or higher aliphatic polyhydric alcohol, an isocyanurate structure (nurate structure) composed of hexamethylene diisocyanate, And biuret which consists of hexamethylene diisocyanate can be mentioned.

Examples of the adduct include the following general formula (8):

(Wherein R ⁹ represents an aliphatic hydrocarbon group having 3 to 20 carbon atoms. K is an integer of 3 to 20).
R ⁹ in the general formula (8) is a hydrocarbon group based on the above trivalent or higher aliphatic polyhydric alcohol, more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and 3 to 6 carbon atoms. The aliphatic hydrocarbon group is more preferable.
The k is a number corresponding to the valence of a trihydric or higher aliphatic polyhydric alcohol. As said k, More preferably, it is an integer of 3-10, More preferably, it is an integer of 3-6.

The isocyanurate structure has the following general formula (4) in the molecule:

It has 1 or 2 or more isocyanurate rings.
Examples of the isocyanurate structure include a trimer obtained by the trimerization reaction of the isocyanate, a pentamer obtained by the pentamerization reaction, and a heptamer obtained by the heptamization reaction.
Among them, the following general formula (9):

The trimer represented by these is preferable.

The biuret is represented by the following general formula (10):

And can be obtained by trimerizing hexamethylene diisocyanate under conditions different from those for obtaining the isocyanurate structure.

As the blocking agent, a compound having active hydrogen is preferably used. As the compound having active hydrogen, for example, at least one selected from the group consisting of alcohols, oximes, lactams, active methylene compounds, and pyrazole compounds is preferably used.

Thus, the blocked isocyanate is obtained by reacting a polyisocyanate compound derived from hexamethylene diisocyanate with a blocking agent, and the blocking agent includes alcohols, oximes, lactams, and active methylene compounds. And at least one selected from the group consisting of pyrazole compounds is one of the preferred embodiments of the present invention.

When the polyisocyanate compound (II) for obtaining the blocked isocyanate is an adduct of hexamethylene diisocyanate and a trihydric or higher aliphatic polyhydric alcohol, the trihydric or higher aliphatic polyhydric alcohol is specifically Glycerol, trimethylolpropane (TMP), 1,2,6-hexanetriol, trimethylolethane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,1,1-tris (bishydroxymethyl) propane , Trihydric alcohols such as 2,2-bis (hydroxymethyl) butanol-3; tetrahydric alcohols such as pentaerythritol and diglycerol; pentahydric alcohols such as arabit, ribitol and xylitol (pentit); Lactitol, allozulcit It includes hexavalent alcohols (hexites) or the like is. Of these, trimethylolpropane and pentaerythritol are particularly preferable.
The adduct is obtained by addition polymerization of hexamethylene diisocyanate and the above trivalent or higher aliphatic polyhydric alcohol.

Specific examples of the compound having active hydrogen to be reacted with the polyisocyanate compound (II) include alcohols such as methanol, ethanol, n-propanol, isopropanol, and methoxypropanol; acetone oxime, 2-butanone oxime, and cyclohexanone. Oximes such as oximes; lactams such as ε-caprolactam; active methylene compounds such as methyl acetoacetate and ethyl malonate; pyrazole compounds such as 3-methylpyrazole, 3,5-dimethylpyrazole, and 3,5-diethylpyrazole And one or more of these can be used.
Among these, active methylene compounds and oximes are preferable, and active methylene compounds are more preferable.

Commercially available block isocyanates include Duranate K6000 (manufactured by Asahi Kasei Chemicals Corporation, HDI active methylene compound block isocyanate), Duranate TPA-B80E (manufactured by Asahi Kasei Chemicals Corporation), Duranate MF-B60X (manufactured by Asahi Kasei Chemicals Corporation). , Duranate 17B-60PX (Asahi Kasei Chemicals Corporation), Coronate 2507 (Nippon Polyurethane Industry Co., Ltd.), Coronate 2513 (Nippon Polyurethane Industry Co., Ltd.), Coronate 2515 (Nippon Polyurethane Industry Co., Ltd.), Sumidur BL- 3175 (manufactured by Sumika Bayer Urethane Co., Ltd.), LuxateHC1170 (manufactured by Olin Chemicals), LuxateHC2170 (manufactured by Olin Chemicals), and the like.

As the curing agent, a polyisocyanate compound derived from hexamethylene diisocyanate (HDI) (hereinafter also referred to as polyisocyanate compound (III)) can be used. As polyisocyanate compound (III), what was mentioned above as polyisocyanate compound (II) is mentioned.

Specific examples of the polyisocyanate compound (III) include Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd., isocyanurate structure of hexamethylene diisocyanate, NCO content 21.1%), Sumijour N3300 (manufactured by Sumika Bayer Urethane Co., Ltd.) Hexamethylene diisocyanate isocyanurate structure), Takenate D170N (Mitsui Chemicals Co., Ltd., hexamethylene diisocyanate isocyanurate structure), Sumidur N3800 (Suika Bayer Urethane Co., Ltd., hexamethylene diisocyanate isocyanurate structure prepolymer) Type).

A solar cell having a cured coating film obtained from the coating composition of the present invention by using, as a curing agent, a polyisocyanate compound derived from isophorone diisocyanate (IPDI) (hereinafter also referred to as polyisocyanate compound (IV)). The back sheet of the module has excellent blocking resistance to the surface with which the cured coating film comes into contact in the winding process or the like.

Examples of the polyisocyanate compound (IV) include an adduct obtained by addition polymerization of isophorone diisocyanate and a trihydric or higher aliphatic polyhydric alcohol, an isocyanurate structure (nurate structure) composed of isophorone diisocyanate, and Biuret made of isophorone diisocyanate can be mentioned.

Examples of the adduct include the following general formula (11):

(In the formula, R ¹⁰ represents an aliphatic hydrocarbon group having 3 to 20 carbon atoms. R ¹¹ represents the following general formula (12):

It is group represented by these. k is an integer of 3-20. ) Is preferred.
R ¹⁰ in the general formula (11) is a hydrocarbon group based on the above trivalent or higher aliphatic polyhydric alcohol, more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and 3 to 6 carbon atoms. The aliphatic hydrocarbon group is more preferable.
The k is a number corresponding to the valence of a trihydric or higher aliphatic polyhydric alcohol. As said k, More preferably, it is an integer of 3-10, More preferably, it is an integer of 3-6.

The isocyanurate structure has the following general formula (4) in the molecule:

It has 1 or 2 or more isocyanurate rings.
Examples of the isocyanurate structure include a trimer obtained by a trimerization reaction of isophorone diisocyanate, a pentamer obtained by a pentamerization reaction, a heptamer obtained by a heptamerization reaction, and the like.
Among them, the following general formula (13):

(Wherein R ¹¹ is the same as R ¹¹ in the general formula (11)). That is, the isocyanurate structure is preferably a trimer of isophorone diisocyanate.

The biuret is represented by the following general formula (14):

(Wherein, R ¹¹ has the general formula (11) in the same as R ¹¹ in.) Is a compound having a structure represented by, under different conditions than the case of obtaining the isocyanurate structure, isophorone It can be obtained by trimerizing diisocyanate.

Above all, the polyisocyanate compound (IV) is preferably at least one selected from the group consisting of the adduct and the isocyanurate structure. That is, the polyisocyanate compound (IV) is selected from the group consisting of an adduct obtained by addition polymerization of isophorone diisocyanate and a trihydric or higher aliphatic polyhydric alcohol, and an isocyanurate structure composed of isophorone diisocyanate. It is preferable that it is at least one kind.

When the polyisocyanate compound (IV) is an adduct of isophorone diisocyanate and a trihydric or higher aliphatic polyhydric alcohol, specific examples of the trihydric or higher aliphatic polyhydric alcohol include glycerol and trimethylol. Propane (TMP), 1,2,6-hexanetriol, trimethylolethane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,1,1-tris (bishydroxymethyl) propane, 2,2-bis ( Trivalent alcohols such as hydroxymethyl) butanol-3; tetravalent alcohols such as pentaerythritol and diglycerol; pentavalent alcohols such as arabit, ribitol and xylitol (pentit); hexavalents such as sorbit, mannitol, galactitol and allozulcit Alcohol (hexit) etc. It is. Of these, trimethylolpropane and pentaerythritol are particularly preferable.

Adducts suitably used in the present invention can be obtained by addition polymerization of isophorone diisocyanate and the above trivalent or higher aliphatic polyhydric alcohol.

As an adduct preferably used in the present invention, specifically, for example, the following general formula (15):

(In the formula, R ¹² represents the following general formula (12):

It is group represented by these. ), That is, a polyisocyanate compound obtained by addition polymerization of isophorone diisocyanate and trimethylolpropane (TMP).

As a commercial item of the polyisocyanate compound (TMP adduct of isophorone diisocyanate) represented by the general formula (12), Takenate D140N (manufactured by Mitsui Chemicals, Inc., NCO content 11%) and the like can be mentioned.

Examples of commercially available isocyanurate structures comprising isophorone diisocyanate include Desmodur Z4470 (manufactured by Sumika Bayer Urethane Co., Ltd., NCO content 11%).

Among these, Takenate D120N (manufactured by Mitsui Chemicals, NCO content 11%) and Sumijour N3300 (manufactured by Sumika Bayer Urethane Co., Ltd., isocyanurate structure of hexamethylene diisocyanate) are more preferable as the curing agent.

It is preferable that content of the hardening | curing agent in the coating composition of this invention is 0.1-5 equivalent with respect to 1 equivalent of curable functional groups in a curable functional group containing fluorine-containing polymer, 0.5-1 More preferably, it is 5 equivalents.

The coating composition of the present invention may contain a drip agent.
When the drip agent is contained, it can be extinguished by dripping with the cured coating film before the base material burns.
The drip agent is preferably at least one selected from the group consisting of phosphate ester compounds and condensed phosphate ester compounds.

Examples of the phosphoric acid ester compounds include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-naphthyl diphenyl phosphate, cresyl di 2,6-xylenyl. Examples include phosphate, tris (chloropropyl) phosphate, tris (tribromoneopentyl phosphate), and the like.

The condensed phosphate ester-based compound is a reaction product (preferably an aromatic condensed phosphate ester) of a phosphorus component, a polyol, and a monoalcohol, and has at least two (preferably two) A compound having a phosphoric acid unit in the molecule is preferred.
Examples of the phosphorus component include phosphorus oxychloride.

Examples of the polyols include non-aromatic polyols (eg, aliphatic polyols) and aromatic polyols (eg, polyhydric phenols, bisphenols). The polyols are preferably aromatic polyols.

Examples of the polyhydric phenols include dihydroxybenzenes, dihydroxybenzenes such as dihydroxybenzene having a substituent, and trihydroxybenzenes corresponding to these dihydroxybenzenes.

Examples of the dihydroxybenzene include catechol, resorcinol, and hydroquinone.
Examples of the dihydroxybenzene having the above substituent include alkyl-dihydroxybenzene (for example, dihydroxytoluene such as 3,5-dihydroxytoluene, 5-hydroxyl-resorcinol, dihydroxyxylene such as 2,6-dihydroxy-p-xylene, etc. mono- or _{di-C 1-10} alkyl - dihydroxybenzene), aryl - dihydroxybenzene (e.g., _{C 6-10} aryl such as 2,4-dihydroxybiphenyl - dihydroxybenzene), halo - dihydroxybenzene (e.g., 2,4 mono- or dihalo, such as difluoro hydroquinone - dihydroxybenzene), acyl - dihydroxybenzene (2,4-dihydroxy acetophenone C _2-6 alkylcarbonyl non like - alkylcarbonyl dihydroxybenzene, etc. - Hydroxybenzene), arylcarbonyl - _{C 6-10} arylcarbonyl such as dihydroxybenzene (2,4-dihydroxybenzophenone - dihydroxybenzene), and the like.
Examples of the trihydroxybenzenes include trihydroxybenzene (pyrogallol, hydroxyhydroquinone, phloroglucinol), trihydroxyacetophenone, and the like.

Examples of the bisphenols include 4,4′-dihydroxybiphenyl, bis (hydroxyphenyl) alkanes, bis (hydroxyphenyl) cycloalkanes, bis (hydroxyphenyl) ethers, bis (hydroxyphenyl) sulfones, and bis (hydroxy Phenyl) sulfoxides, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl-alkyl) arenes and the like.

Examples of the bis (hydroxyphenyl) alkanes include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 1,1-bis (4-hydroxyphenyl) -1-phenyl. Ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-isopropylphenyl) propane, 2 , 2-bis (3-t-butyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, 2,2-bis ( 3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2 Bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, bis (4 -Hydroxyphenyl) diphenylmethane and the like may be substituted bis (hydroxyphenyl) C _1-10 alkane.

Examples of the bis (hydroxyphenyl) cycloalkanes include 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, Examples thereof include bis (hydroxyphenyl) C _5-10 cycloalkane which may have a substituent such as 1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane.

Examples of the bis (hydroxyphenyl) ethers include 4,4′-dihydroxydiphenyl ether.
Examples of the bis (hydroxyphenyl) sulfones include 4,4′-dihydroxydiphenyl sulfone.
Examples of the bis (hydroxyphenyl) sulfoxides include 4,4′-dihydroxydiphenyl sulfoxide.
Examples of the bis (hydroxyphenyl) sulfides include 4,4′-dihydroxydiphenyl sulfide.
Examples of the bis (hydroxyphenyl-alkyl) arenes include 4,4 ′-(m-phenylenediisopropylidene) diphenol.

Among them, dihydroxybenzenes are preferable as the polyols because they are inexpensive and easily available, and have a substituent of dihydroxybenzene (resorcinol, hydroquinone), alkyl-dihydroxybenzene or halo-dihydroxybenzene. Dihydroxybenzene (especially resorcinol which may have a substituent) may be more preferable.

Examples of the monoalcohols include non-aromatic monoalcohols (such as aliphatic alcohols) and monohydroxyarenes.
The monoalcohols are preferably monohydroxyarenes.

Examples of the monohydroxyarenes include phenol and phenols having a substituent.
Examples of the phenols having a substituent include monohydroxy C _6-10 arenes which may have a substituent such as a phenol having a hydrocarbon group, an alkoxyphenol, a halophenol, and an acylphenol.

Examples of the phenol having a hydrocarbon group include o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, and 2,6-diphenol. Mono- or di-C _1-10 alkyl phenols such as t-butylphenol, preferably mono- or di-C _1-6 alkyl phenols, more preferably di-C _1-4 alkyl phenols, alkyl phenols; aryl phenols (mono-such as o-phenyl phenols) Or di-C _{6-10 arylphenol} ); cycloalkylphenol (mono- or di-C _5-10 cycloalkylphenol such as 2-cyclohexylphenol) and the like.

Examples of the alkoxyphenol include mono or C _1-10 alkoxyphenol such as o-methoxyphenol.
Examples of the halophenol include mono- or dihalophenol such as chlorophenol.
Examples of the acylphenol include alkylcarbonylphenol (eg, C _1-6 alkyl-carbonylphenol such as hydroxyacetophenone), arylcarbonyl-dihydroxybenzene (eg, C _6-10 aryl-carbonylphenol such as hydroxybenzophenone), and the like. It is done.

Especially, as a drip agent, a phosphate ester type compound is preferable and cresyl diphenyl phosphate is more preferable at the point that viscosity is low, and it is cheap and can be obtained easily.

It is preferable that content of a drip agent is 1-20 mass parts with respect to 100 mass parts of curable functional group containing fluorine-containing polymers. When the content of the drip agent is in the above range, improvement in flame retardancy can be expected.
The content of the drip agent is more preferably 2 parts by mass or more, further preferably 2.5 parts by mass or more, more preferably 15 parts by mass or less, relative to 100 parts by mass of the curable functional group-containing fluoropolymer. 10 parts by mass The following is more preferable.

The coating composition of the present invention may contain an inorganic pigment.
The inorganic pigment is not particularly limited as long as it is a generally known inorganic pigment. For example, titanium oxide, zinc oxide, aluminum oxide, iron oxide, silicon oxide, barium sulfate, calcium carbonate, carbon black, titanium yellow, chrome green , Ultramarine, aluminum powder, mica, barium carbonate, talc and the like. Of these, titanium oxide and carbon black are preferable because they are excellent in dispersibility in paints and ultraviolet shielding properties.

The content of the inorganic pigment is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the curable functional group-containing fluorine-containing polymer in the coating composition. It can disperse | distribute well in a coating material as content of an inorganic pigment is in the above-mentioned range.
The content of the inorganic pigment is more preferably 30 parts by mass or more, further preferably 50 parts by mass or more, more preferably 130 parts by mass or less, and more preferably 100 parts by mass or less with respect to 100 parts by mass of the curable functional group-containing fluoropolymer. Further preferred.

The coating composition of the present invention may further contain other components as necessary. Examples of other components include other resins and additives. Examples of the additive include a dispersant that improves the dispersibility of the inorganic pigment, a precipitation stabilizer that prevents sedimentation of the inorganic pigment, a curing accelerator, Examples thereof include an antifoaming agent, a leveling agent, an ultraviolet absorber, a light stabilizer, a thickener, an adhesion improving agent, a matting agent, and a hydrophilizing agent.

Examples of the curing accelerator include organic tin compounds, acidic phosphate esters, reaction products of acidic phosphate esters and amines, saturated or unsaturated polycarboxylic acids or acid anhydrides thereof, organic titanate compounds, amine compounds, Examples include lead octylate.

1 type may be used for a hardening accelerator and it may use 2 or more types together. As for the compounding quantity of a hardening accelerator, about 1.0 * 10 ^{< -6} > -1.0 * 10 ^<-2 > mass part is preferable with respect to 100 mass parts of curable functional group containing fluorine-containing polymers, 5.0 * 10 <^-5> -. About 1.0 × 10 ⁻³ parts by mass is more preferable.

As the ultraviolet absorber, both organic and inorganic ultraviolet absorbers can be used. Examples of the organic compound type include salicylic acid ester type, benzotriazole type, benzophenone type, cyanoacrylate type and other ultraviolet absorbers, and inorganic type is preferably a filler type inorganic ultraviolet absorber such as zinc oxide and cerium oxide. .

Examples of the inorganic pigment dispersant include Disparon 2150, Disparon DA-325, DA-375, DA-1200 (trade name, manufactured by Enomoto Kasei Co., Ltd.), Floren G-700, G-900 (trade name, Kyoeisha Chemical Co., Ltd.) SOLPERSE 26000, 32000, 36000, 36600, 41000, 55000, 76500 (trade name, manufactured by Nippon Lubrizol), DISPERBYK-102, 106, 110, 111, 140, 142, 145, 170, 171, 174, 180 (Trade name, manufactured by Big Chemie Japan).
The amount of the dispersing agent is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the inorganic pigment.

As the precipitation stabilizer for inorganic pigments, for example, an associative acrylic polymer having an acid group and a base, a reaction product of a carboxylic acid and a nitrogen-containing compound of hydroxyamine or hydroxyimine, and the like can be used. Specific examples of the sedimentation stabilizer include SOLTHIX 250 (trade name, manufactured by Nihon Lubrizol), Alkaterage T (trade name, manufactured by Angus Chemical), and the like.
The amount of the precipitation stabilizer is preferably 0.05 to 20% by mass in the coating composition.

Examples of the hydrophilizing agent include those that are unevenly distributed on the surface of the cured coating film and can retain a hydroxyl group, and specifically include GH-701 manufactured by Daikin Industries, Ltd. As for the compounding quantity of a hydrophilizing agent, it is desirable that it is 0.01-50 mass% in the ratio with respect to the non volatile matter in a coating composition.

The coating composition of the present invention can be prepared by mixing or dispersing the above-described curable functional group-containing fluorine-containing polymer, flame retardant, and, if necessary, other components in an organic solvent.
The mixing and dispersion are not particularly limited, and can be performed using a known apparatus such as a paint shaker, a bead mill, or a kneader.
The solid content concentration of the coating composition of the present invention is not particularly limited, and may be appropriately adjusted according to the method of use.

The method for forming a cured coating film using the coating composition of the present invention is not particularly limited, but usually, the coating composition of the present invention containing a curing agent is applied onto a substrate and cured. Form a cured coating.
The said coating is not specifically limited, What is necessary is just to use a well-known method, for example, a roll coat, a curtain coat, a spray coat, a die coat, a gravure coat etc. are mentioned.
The curing may be appropriately selected from drying, heating, radiation irradiation, or the like according to the components of the coating composition.

Thus, the coating composition of the present invention contains a specific flame retardant. For this reason, the cured coating film excellent in the flame retardance can be formed. Moreover, the obtained cured coating film is excellent in weather resistance, moisture resistance, ultraviolet resistance, blocking resistance and adhesion in addition to flame retardancy. For this reason, the coating composition of this invention can be used suitably as a coating agent for back sheets of a solar cell module.

A cured coating film formed using the coating composition of the present invention is also one aspect of the present invention. By forming a cured coating film using the coating composition of the present invention on various resin base materials such as vinyl chloride, polycarbonate, acrylic resin, etc., the flame retardancy and weather resistance of the resin base material are improved. Or further imparting a hydrophilic surface.

The back sheet | seat of the solar cell module provided with the cured coating film formed using the coating composition of this invention is also one of this invention.
That is, the present invention also includes a base material and a fluororesin layer on at least one surface of the base material, and the fluororesin layer includes a cured coating film formed using the above-described coating composition. It is also a back sheet of the solar cell module characterized by this.

The back sheet of the solar cell module of the present invention has a base material and a fluororesin layer on at least one surface of the base material.
As said base material, the resin sheet generally used for the back seat | sheet of a solar cell module is mentioned.
Examples of the resin sheet include polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polytetrafluoroethylene, polyamide, polyacrylonitrile, polyvinyl chloride, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate ( PET), polyoxymethylene, polycarbonate, polyphenylene oxide, polyester urethane, poly m-phenylene isophthalamide, and a sheet made of a polymer such as poly p-phenylene terephthalamide.
Of these, polyethylene terephthalate (PET) is preferable.

The substrate may also be a water impermeable sheet. By using a water-impermeable sheet, it is possible to prevent moisture from permeating through the sealing material and the solar battery cell when the back sheet of the present invention is used to form a solar battery module.
Examples of the water-impermeable sheet include PET sheets, silica-deposited PET sheets, and metal sheets such as aluminum and stainless steel.
Of these, a silica-deposited PET sheet and a PET sheet are preferable in that they are lightweight, inexpensive, and flexible.

Moreover, in order to improve adhesiveness with the fluororesin layer on the said base material or another layer, a sheet | seat, etc., the said base material may be what surface-treated. Examples of the surface treatment include corona discharge treatment, plasma discharge treatment, chemical conversion treatment, and blast treatment in the case of a metal sheet. Any processing may adopt a conventionally known method.
The surface treatment may be formed on one surface of the base material or may be formed on both surfaces.

The substrate preferably has a thickness of 10 to 500 μm, and more preferably 50 to 300 μm.

The back sheet of the solar cell module of the present invention has a fluororesin layer on at least one surface on the substrate. The said fluororesin layer is a cured coating film formed using the coating composition of this invention mentioned above.
The fluororesin layer can be formed in the same manner as the method for forming a cured coating film using the coating composition of the present invention described above.
The coating on the substrate may be performed by directly applying the coating composition to the substrate, or may be performed by applying it through a primer layer or the like.
The primer layer may be formed by a conventional method using a conventionally known primer coating. Examples of the primer coating include epoxy resin, urethane resin, acrylic resin, silicone resin, polyester resin, and the like.

The film thickness of the fluororesin layer is preferably 5 μm or more from the viewpoint of good concealability, weather resistance, chemical resistance, and moisture resistance. More preferably, it is 7 micrometers or more, More preferably, it is 10 micrometers or more. The upper limit is preferably about 1000 μm, and more preferably 100 μm because if the thickness is too thick, the effect of reducing the weight cannot be obtained. As said film thickness, 10-40 micrometers is especially preferable.

The fluororesin layer preferably has a degree of cross-linking calculated from Soxhlet extraction with acetone as a gel fraction of 90 to 100%, more preferably 95 to 100%, and more preferably 98 to 100%. Further preferred.

The back sheet of the solar cell module of the present invention may also have the fluororesin layer on both surfaces of the substrate. In the case of having a fluororesin layer on both surfaces of the base material, these two fluororesin layers may be formed from the components included in the above-described range, and even if the fluororesin layer is composed of the same components, It may be a fluororesin layer made of different components.
Moreover, in order to improve adhesiveness with another layer, you may surface-treat to the said fluororesin layer.
Examples of the surface treatment include corona discharge treatment, plasma discharge treatment, chemical conversion treatment, and coating treatment such as a silane coupling agent.

The back sheet of the solar cell module of the present invention may have other material layers in addition to the base material and the fluororesin layer described above. When the said back sheet has another material layer, it is preferable to laminate | stack in order of another material layer, a base material, and a fluororesin layer.
Examples of the other material layers include an adhesive layer made of an adhesive, a cured coating film of a fluorine-containing polymer paint having no curable functional group, a fluorine-containing polymer sheet, a polyester sheet, or a coating film of a polyester paint (another sheet or Coating film). These layers may be laminated via a primer layer or the like.

Examples of the adhesive layer include known urethane adhesives, polyester adhesives, epoxy adhesives, nylon adhesives, ethylene-vinyl acetate adhesives, acrylic adhesives, rubber adhesives, and the like. Examples include a layer made of an adhesive.

As a cured coating film of the above-mentioned fluorine-containing polymer paint having no curable functional group, for example, a cured coating of a paint in which tetraalkoxysilane or a partial hydrolyzate thereof is blended with PVdF described in JP-A-2004-214342. Film, cured coating film of mixed paint of VdF / TFE / CTFE copolymer and alkoxysilane unit-containing acrylic resin, cured coating film of mixed paint of VdF / TFE / HFP copolymer and hydroxyl group-containing acrylic resin, VdF / Examples thereof include a cured coating film of a paint in which an aminosilane coupling agent is blended with an HFP copolymer. The film thickness is usually preferably 5 to 300 μm from the viewpoint of good concealability, weather resistance, chemical resistance, and moisture resistance. More preferably, it is 10-100 micrometers, More preferably, it is 10-50 micrometers.

Examples of the fluoropolymer sheet include a PVdF sheet, a PVF sheet, a PCTFE sheet, a TFE / HFP / ethylene copolymer sheet, a TFE / HFP copolymer (FEP) sheet, a TFE / PAVE copolymer (PFA) sheet, and ethylene. Examples thereof include fluorine-containing polymer sheets used in current backsheets such as a / TFE copolymer (ETFE) sheet and an ethylene / CTFE copolymer (ECTFE) sheet. The film thickness is usually preferably 5 to 300 μm from the viewpoint of good weather resistance. More preferably, it is 10-100 micrometers, More preferably, it is 10-50 micrometers.

As said polyester sheet, what is used with the conventional back sheet can be used as it is, and the adhesion to the water-impermeable sheet is acrylic adhesive, urethane adhesive, epoxy adhesive, polyester adhesive. Etc. The film thickness is usually preferably 5 to 300 μm from the viewpoint of good weather resistance, cost, and transparency. More preferably, it is 10-100 micrometers, More preferably, it is 10-50 micrometers.

Examples of the polyester paint include those using a saturated polyester resin using polyvalent carboxylic acid and polyhydric alcohol, and those using an unsaturated polyester resin using maleic anhydride, fumaric acid and the like and glycols, etc. A coating film can be formed by a coating method such as roll coating, curtain coating, spray coating, or die coating. The film thickness is preferably 5 to 300 μm from the viewpoint of good concealability, weather resistance, chemical resistance, and moisture resistance. More preferably, it is 10-100 micrometers, More preferably, it is 10-50 micrometers.

When the back sheet of the solar cell module of the present invention forms a fluororesin layer using the coating composition by the above-described method on the base material, forms the other material layer, or stacks the sheets. Good. Moreover, it is good to manufacture so that it may become a desired layer structure by a well-known method.

The present invention is also a solar cell module including the back sheet of the solar cell module described above.
The solar cell module of the present invention preferably has the above-described back sheet and a sealing material layer formed on the back sheet.
The encapsulant layer is a layer for encapsulating the solar battery cell, and is composed of ethylene / vinyl acetate copolymer (EVA), polyvinyl butyral (PVB), silicone resin, epoxy resin, acrylic resin, and the like. Is preferred. Of these, EVA is preferably used.

The schematic schematic diagram of an example of the preferable embodiment of the solar cell module of this invention is shown in FIG.1 and FIG.2.
In the first structure shown in FIG. 1, the solar battery cell 1 is sealed with a sealing material layer 2, and the sealing material layer 2 is sandwiched between a surface layer 3 and a back sheet 4. The back sheet 4 includes a base material 5 and a fluororesin layer 6, and is provided so that the fluororesin layer 6 is the outermost layer.

The surface layer 3 is a layer for protecting the light receiving surface of the solar cell module, and usually a glass plate is used, but a flexible material such as a resin sheet may be used.

In the second structure shown in FIG. 2, the back sheet 4 has a three-layer structure having the other material layer 7 on one surface of the substrate 5 and the fluororesin layer 6 on the other surface. The fluororesin layer 6 is provided as the outermost layer.

The solar cell module of the present invention may further have a junction box. The junction box is connected to electrodes and wiring for extracting output power from the solar cells (electrodes and wiring connected to the solar cells) and cables for extracting output power to the outside of the solar cell module. It is a box for storing terminals.
The junction box is preferably provided on the back sheet side surface of the solar cell module via an adhesive layer. The adhesive layer may be a layer made of a known adhesive.

As mentioned above, according to this invention, the coating composition which can form the cured coating film which has the outstanding flame retardance can be provided. The cured coating film formed on the substrate using the coating composition of the present invention can be suitably used as a back sheet for a solar cell module.

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

(Example 1)
With respect to 100 parts by mass of Zeffle GK570 (solid content 65 mass%, manufactured by Daikin Industries, Ltd.), 52 parts by mass of butyl acetate, 54 parts by mass of titanium oxide D-918 (manufactured by Sakai Chemical Industry Co., Ltd.), SCFR- as a flame retardant 26 parts by mass of 200 (manufactured by Sakai Chemical Industry Co., Ltd.) was added to prepare a coating composition.
After adding 14 parts by mass of Sumidur N3300 (manufactured by Sumika Bayer Urethane Co., Ltd.) to the obtained coating composition, the coating composition was applied on a polypropylene plate to form a coating film. After cured at 14 ° C. for 14 hours, it was peeled from the polypropylene plate and cured at 80 ° C. for 6 hours to prepare a cured coating film (test piece) having a thickness of 2 mm. About this test piece, when the combustion test (ASTM D3801) was performed based on UL-94V specification, evaluation of V-0 was obtained.

The UL-94V standard is a combustion test of plastic materials for parts of equipment specified by the US Underwriters Laboratories (UL). A flame of a gas burner is applied to the lower end of a sample piece held vertically for 10 seconds. This is a method for evaluating the flame retardancy from the afterflame time after dipping and the drip, and is evaluated according to the criteria shown in Table 1 below.

ここで残炎時間とは、着火源を遠ざけた後の、試験片の有炎燃焼を続ける時間の長さである。また、ドリップによる綿着火とは、試験片の下端から約３００ｍｍ下にある標識用の綿が、試験片からの滴下（ドリップ）物によって着火されるかどうかによって決定される。

Here, the after-flame time is the length of time for which the flammable combustion of the test piece is continued after the ignition source is moved away. The cotton ignition by the drip is determined by whether or not the labeling cotton, which is about 300 mm below the lower end of the test piece, is ignited by a drip from the test piece.

(Example 2)
Example 1 except that 6.5 parts by mass of SAYTEX-8010 (manufactured by Albemarle) and 3.3 parts by mass of antimony trioxide (manufactured by Wako Pure Chemical Industries, Ltd.) were added in place of SCFR-200 of Example 1. In the same manner, a coating composition was prepared. Using the obtained coating composition, a coating film was produced in the same manner as in Example 1, and a combustion test was performed based on the UL-94V standard. As a result, an evaluation of V-0 was obtained.

(Reference Example 1)
A coating composition was prepared in the same manner as in Example 1 except that 9.8 parts by mass of CDP (cresyl diphenyl phosphate, manufactured by Daihachi Chemical Industry Co., Ltd.) was added instead of SCFR-200 in Example 1. Using the obtained coating composition, a coating film was produced in the same manner as in Example 1, and when a combustion test was performed based on the UL-94V standard, the coating film burned.

(Reference Example 2)
A coating composition was prepared in the same manner as in Example 1 except that 9.8 parts by mass of CR-741 (aromatic condensed phosphate ester, manufactured by Daihachi Chemical Industry Co., Ltd.) was added instead of SCFR-200 in Example 1. Was prepared. Using the obtained coating composition, a coating film was prepared in the same manner as in Example 1, and when a combustion test was performed based on the UL-94V standard, the coating film burned.

(Reference Example 3)
A coating composition was prepared in the same manner as in Example 1 except that 19.5 parts by mass of FP-390 (phosphazene oligomer, manufactured by Fushimi Pharmaceutical Co., Ltd.) was added instead of SCFR-200 of Example 1. Using the obtained coating composition, a coating film was prepared in the same manner as in Example 1, and when a combustion test was performed based on the UL-94V standard, the coating film burned.

(Example 3)
65 parts by mass of butyl acetate, 54 parts by mass of titanium oxide D-918 (manufactured by Sakai Chemical Industry Co., Ltd.), and 100% by mass of SCFR- as a flame retardant A coating composition was prepared by adding 6.5 parts by mass of 200 (manufactured by Sakai Chemical Industry Co., Ltd.). After adding 14 parts by mass of Sumidur N3300 (manufactured by Sumika Bayer Urethane Co., Ltd.) to the obtained coating composition, the coating composition was applied on a PET plate (thickness: 188 μm) to form a coating film, The coating film was cured at 120 ° C. for 2 minutes and then at 40 ° C. for 48 hours to prepare a cured coating film having a thickness of 10 μm. When a cured coating film was formed on this PET plate, a test piece was used, and a combustion test (ASTM D4804) was performed on this test piece in accordance with the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained. It was.

The UL-94 VTM standard is a combustion test of plastic materials for parts of equipment defined by the US Underwriters Laboratories (UL). A cylindrical test piece is held vertically, This is a method for evaluating the flame retardance from the after-flame time after dipping the flame of the gas burner at the lower end for 3 seconds and the drip, and is evaluated according to the criteria shown in Table 3 below.

Example 4
The butyl acetate in Example 3 was 52 parts by mass, and instead of SCFR-200, 6.5 parts by mass of SAYTEX-8010 (manufactured by Albemarle) and 3.3 parts by mass of antimony trioxide (manufactured by Wako Pure Chemical Industries, Ltd.) A coating composition was prepared in the same manner as in Example 3 except that part of the coating composition was added. Using the obtained coating composition, a cured coating film was produced in the same manner as in Example 3, and a combustion test was performed based on the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained.

(Example 5)
A coating composition was prepared in the same manner as in Example 3 except that 71 parts by mass of butyl acetate in Example 3 and 9.8 parts by mass of the flame retardant SCFR-200 were added. Using the obtained coating composition, a cured coating film was produced in the same manner as in Example 3, and a combustion test was performed based on the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained.

(Example 6)
A coating composition was prepared in the same manner as in Example 3, except that 62 parts by mass of butyl acetate in Example 3 and 5.2 parts by mass of the flame retardant SCFR-200 were added. Using the obtained coating composition, a cured coating film was produced in the same manner as in Example 3, and a combustion test was performed based on the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained.

(Reference Example 4)
A coating composition was prepared in the same manner as in Example 3, except that 52 parts by mass of butyl acetate and 19.5 parts by mass of the flame retardant SCFR-200 were added. Using the obtained coating composition, a cured coating film was prepared in the same manner as in Example 3, and when a combustion test was performed based on the UL-94 VTM standard, the coating film burned.

(Reference Example 5)
A coating composition was prepared in the same manner as in Example 3, except that 52 parts by mass of butyl acetate and 13 parts by mass of the flame retardant SCFR-200 were added. Using the obtained coating composition, a cured coating film was prepared in the same manner as in Example 3, and when a combustion test was performed based on the UL-94 VTM standard, the coating film burned.

(Reference Example 6)
A coating composition was prepared in the same manner as in Example 3 except that 61 parts by mass of butyl acetate and 4.6 parts by mass of the flame retardant SCFR-200 were used. Using the obtained coating composition, a cured coating film was prepared in the same manner as in Example 3, and when a combustion test was performed based on the UL-94 VTM standard, the coating film burned.

(Reference Example 7)
A coating composition was prepared in the same manner as in Example 3 except that 57 parts by mass of butyl acetate in Example 3 and 2.6 parts by mass of the flame retardant SCFR-200 were added. Using the obtained coating composition, a cured coating film was prepared in the same manner as in Example 3, and when a combustion test was performed based on the UL-94 VTM standard, the coating film burned.

(Example 7)
65 parts by mass of butyl acetate, 54 parts by mass of titanium oxide D-918 (manufactured by Sakai Chemical Industry Co., Ltd.), and 100% by mass of SCFR- as a flame retardant A coating composition was prepared by adding 6.5 parts by mass of 200 (manufactured by Sakai Chemical Industry Co., Ltd.) and 3.3 parts by mass of CDP (cresyl diphenyl phosphate, manufactured by Daihachi Chemical Industry Co., Ltd.) as a drip agent.
After adding 14 parts by mass of Sumidur N3300 (manufactured by Sumika Bayer Urethane Co., Ltd.) to the obtained coating composition, the coating composition was applied on a PET plate (thickness: 188 μm) to form a coating film, The coating film was cured at 120 ° C. for 2 minutes and then at 40 ° C. for 48 hours to prepare a cured coating film having a thickness of 10 μm. When a cured coating film was formed on this PET plate was used as a test piece, and the test piece was subjected to a combustion test in accordance with the UL-94 VTM standard, an evaluation of VTM-2 was obtained.

(Example 8)
A coating composition was prepared in the same manner as in Example 7 except that the amount of the drip agent added was 1.6 parts by mass. Using the obtained coating composition, a cured coating film was produced in the same manner as in Example 7, and a combustion test was performed based on the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained.

Example 9
A coating composition was prepared in the same manner as in Example 7 except that 3.3 parts by mass of CR-741 (aromatic condensed phosphate ester, manufactured by Daihachi Chemical Industry Co., Ltd.) was added as a drip agent instead of CDP. Using the obtained coating composition, a cured coating film was produced in the same manner as in Example 7, and a combustion test was performed based on the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained.

(Example 10)
A coating composition was prepared in the same manner as in Example 9 except that the amount of the drip agent added was 1.6 parts by mass. Using the obtained coating composition, a cured coating film was produced in the same manner as in Example 7, and a combustion test was performed based on the UL-94 VTM standard. As a result, an evaluation of VTM-2 was obtained.

ADVANTAGE OF THE INVENTION According to this invention, the cured coating film which has the outstanding flame retardance, the back sheet | seat of a solar cell module, and a solar cell module can be provided.

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Sealing material layer 3 Surface layer 4 Back sheet 5 Base material 6 Fluororesin layer 7 Other material layers

Claims (9)

Containing a curable functional group-containing fluorine-containing polymer, a flame retardant and an organic solvent,
The flame retardant is a phosphorus nitrogen-containing composition (A),
Phosphorus nitrogen-containing composition (A) is a mixture of piperazine pyrophosphate and melamine cyanurate,
A coating composition, wherein the phosphorus nitrogen-containing composition (A) is 8 to 19 parts by mass with respect to 100 parts by mass of the curable functional group-containing fluorine-containing polymer. Containing a curable functional group-containing fluorine-containing polymer, a flame retardant and an organic solvent,
The flame retardant is a mixture (B) of a bromine-containing compound and an antimony-containing compound,
In the mixture (B) of the bromine-containing compound and the antimony-containing compound, the bromine-containing compound is decabromodiphenyl oxide, 1,2-bis (2,3,4,5,6-pentabromophenyl) ethane, tris ( Tribromophenoxy) triazine, ethylenebistetrabromophthalimide, polybromophenylindane, brominated phenylene oxide, and polypentabromobenzyl acrylate, and the antimony-containing compound is Antimony oxide,
A coating composition comprising 1 to 30 parts by mass of a bromide-containing compound and 0.5 to 15 parts by mass of an antimony-containing compound with respect to 100 parts by mass of the curable functional group-containing fluorine-containing polymer. A mixture (B) of a bromine-containing compound and an antimony-containing compound is
The bromine-containing compound is 1,2-bis (2,3,4,5,6-pentabromophenyl) ethane;
The coating composition according to claim 2 , wherein the antimony-containing compound is antimony trioxide. The curable functional group-containing fluorine-containing polymer is a polymer unit based on a fluorine-containing monomer, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an acid anhydride monomer, an amino group-containing monomer, and The coating composition according to claim 1, 2 or 3 , comprising a polymer unit based on at least one curable functional group-containing monomer selected from the group consisting of silicone vinyl monomers. The coating composition according to claim 4 , wherein the fluorine-containing monomer is at least one selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, and vinylidene fluoride. Claim 1, 2, 3, 4 or 5 coating composition wherein the backsheet for coating the solar cell module. A cured coating film formed using the coating composition according to claim 1, 2, 3, 4, 5 or 6 . A base material, and a fluororesin layer on at least one surface of the base material;
The said fluororesin layer is a cured coating film formed using the coating composition of Claim 1, 2, 3, 4, 5 or 6, The solar cell module backsheet characterized by the above-mentioned. A solar cell module comprising the back sheet of the solar cell module according to claim 8 .

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