JP6485369B2 - Anchor coating agent - Google Patents

Description

  The present invention relates to an anchor coating agent used for producing a solar cell module or the like.

  2. Description of the Related Art In recent years, solar cells (solar power generation) that have attracted attention as clean energy are configured as solar power modules that include a sealing material and a protective material on both sides of a solar cell element. Typical examples of the protective material include a glass plate and a solar cell protective sheet (hereinafter also referred to as “protective sheet”). A glass plate is very excellent in transparency, weather resistance, and scratch resistance, but has problems in cost, safety, and workability. On the other hand, since the protective sheet is excellent in terms of cost, safety, and workability, various types of protective sheets have been proposed (for example, Patent Document 1). As the sealing material, an ethylene-vinyl acetate copolymer (hereinafter referred to as “EVA”), which is highly transparent and excellent in moisture resistance, is usually used.

Various performances are required for the protective sheet, and among them, the peel strength from the sealing material and the adhesion durability for maintaining the peel strength are important performances. If the protective sheet has insufficient peel strength from the sealing material, the protective sheet is peeled off, the solar cell element cannot be protected from moisture and external factors, and the output of the solar cell is deteriorated.
As a method of ensuring the peel strength with the sealing material, (1) a method of applying an anchor coating agent to the surface of the protective sheet in contact with the sealing material, or (2) a surface of the protective sheet in contact with the sealing material Although the method of using a film with high peeling strength with a stopping material is mentioned, the method of said (1) attracts attention in recent years from a viewpoint of cost or efficiency.
Various types of anchor coating agents are known. For example, Patent Document 2 discloses an anchor coating agent containing a vinyl polymer having an ethylenically unsaturated double bond at the end of a side chain.

Japanese Patent Application Laid-Open No. 2004-200322 JP2013-071948A

  However, conventional anchor coating agents contain ethylenically unsaturated double bonds, so they are unstable in the environment such as light and heat, and may deteriorate during storage such as thickening, gelling, and coloring. Even after the anchor coat agent was applied and the resin layer was formed, there was a problem that it was denatured by light and heat and the peel strength was lowered, so it was dealt with by adding a polymerization inhibitor, but it was photoreactive There was a problem that decreased.

  An object of this invention is to provide the anchor coating agent which is excellent in storage stability and excellent in peeling strength with a base material or a to-be-adhered body.

  The anchor coating agent of the present invention includes a heterocyclic ring-containing resin (A) and a curing agent (B), and the heterocyclic ring has a carbon-carbon double bond.

  The present invention also relates to a coated product comprising a substrate and a resin layer containing the anchor coating agent.

  According to the present invention, the anchor coating agent of the present invention includes a heterocyclic ring-containing resin (A) having a carbon-carbon double bond in the heterocyclic ring, so that the storage stability is improved and the anchor coating agent is applied. The effect of improving the peel strength between the substrate to be bonded and the adherend to be adhered to the substrate was obtained.

  According to the present invention, an anchor coating agent having excellent storage stability and excellent peel strength with respect to a substrate or an adherend can be provided.

Sectional drawing of the module for solar cells.

In this specification, “film” and “sheet” are not distinguished by thickness. In other words, the “sheet” in this specification includes a thin film-like material, and the “film” in this specification includes a thick sheet-like material.
Further, in this specification, “(meth) acrylic copolymer” includes “acrylic copolymer”, “methacrylic copolymer”, and “acrylic-methacrylic copolymer”. Yes, “(meth) acryloyl” means “acryloyl” and “methacryloyl”, and “(meth) acryl” means “acryl” and “methacryl”. Further, the adherend refers to a counterpart to which the base material on which the resin layer is formed is bonded.

  The anchor coating agent of the present invention includes a heterocyclic ring-containing resin (A) and a curing agent (B), and the heterocyclic ring has a carbon-carbon double bond. The anchor coating agent is applied onto the substrate to form a resin layer. And a base material with a resin layer can obtain high peeling strength by bonding with an adherend. The adherend is preferably various plastic materials, and is preferably EVA or a polyolefin film used for a solar cell encapsulant.

  The heterocyclic ring-containing resin (A) used in the present invention (hereinafter referred to as “resin (A)”) is a resin having a heterocyclic ring and a resin having a carbon-carbon double bond in the heterocyclic ring. An anchor coating agent containing a resin (A) and a curing agent is excellent in peel strength from an adherend (for example, an EVA sheet of a solar cell sealing material) that undergoes radical crosslinking when thermobonding with the adherend. In addition, it has a surprising effect of excellent storage stability.

  The factor that the anchor coating agent of the present invention can achieve both the peel strength from the adherend and the storage stability is that the heterocyclic ring (also referred to as a heterocycle) of the resin (A) having a carbon-carbon double bond in the ring. Since the reactivity is low as compared with conventional ethylenically unsaturated double bonds, it is less likely to thicken or gel due to light or heat during storage. On the other hand, since the heterocyclic ring having a carbon-carbon double bond in the ring has radical crosslinkability, it sufficiently reacts with the radical crosslinkable adherend such as the EVA sheet to obtain good peel strength. . Thus, the anchor coat agent containing resin (A) has both storage stability and peel strength.

  Examples of the heterocyclic ring having a carbon-carbon double bond include pyrrole, furan, thiophene, pyridine, azepine, oxepin, thiepine, imidazole, pyrazole, oxazole, thiazole and the like. Among these, a 5-membered heterocyclic ring is preferable, and furan is more preferable.

  As the type of the resin (A), for example, (meth) acrylic resin, polyester, polyurethane, polyolefin and the like are preferable.

  The (meth) acrylic resin can be synthesized by polymerizing a (meth) acrylic monomer. Examples of (meth) acrylic monomers include (meth) acrylic acid alkyl esters, hydroxyl group-containing monomers, carboxyl group-containing monomers, glycidyl group-containing monomers, and other vinyl monomers.

  Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, normal butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate and the like.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.

  Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, citraconic acid and the like.

  Examples of the glycidyl group-containing monomer include glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, and the like.

  Examples of other vinyl monomers include monomers copolymerizable with (meth) acrylic monomers such as vinyl acetate, maleic anhydride, vinyl ether, vinyl propionate, and styrene.

  As a method for polymerizing the (meth) acrylic monomer, a known polymerization method such as normal radical polymerization, for example, solution polymerization, bulk polymerization, emulsion polymerization, or the like can be used. Among these methods, solution polymerization is preferable. The polymerization initiator used for the polymerization reaction is preferably an organic peroxide, an azo initiator, or the like. Examples of the organic peroxide include benzoyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, lauroyl peroxide, and the like. Examples of the azo initiator include azobisisobutyronitrile.

Polyester can be synthesized by reacting a carboxylic acid component and a hydroxyl component according to a conventional method (esterification reaction, transesterification reaction).
Examples of the carboxylic acid component include benzoic acid, p-tert-butylbenzoic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, azelaic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride Examples include acid, fumaric acid, itaconic acid, tetrachlorophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, trimellitic anhydride, methylcyclohexericarboxylic anhydride, pyromellitic anhydride, ε-caprolactone, and fatty acid.

  Examples of the hydroxyl component include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, 3-methylpentanediol, 1,4- In addition to diol components such as cyclohexanedimethanol, polyfunctional alcohols such as glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, and dipentaerythritol can be mentioned.

  Polyurethane can be synthesized by reacting an isocyanate compound and a hydroxyl component according to a conventional method.

  Examples of the isocyanate compound include trimethylene diisocyanate (TDI), hexamethylene diisocyanate (HDI), methylenebis (4,1-phenylene) = diisocyanate (MDI), 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI). ), Diisocyanates such as xylylene diisocyanate (XDI), trimethylolpropane adducts of these diisocyanates, isocyanurates that are trimers of these diisocyanates, and burette conjugates of these diisocyanates, polymeric diisocyanates, etc. .

  Examples of the hydroxyl component constituting the polyurethane include polyester polyol, polyether polyol, polycarbonate polyol, and polyurethane polyol which is a reaction product of these polyol and diisocyanate.

  Examples of the polyester polyol include a polyester polyol having a hydroxyl group at the molecular end in the polyester described above.

  Polyether polyol is obtained by polymerizing an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran using a compound having two or more hydroxyl groups such as ethylene glycol or propylene glycol, or water as an initiator. Examples include synthesized polyether polyols. Specific examples include compounds having 2 or more functional groups such as polypropylene glycol, polyethylene glycol, and polytetramethylene glycol.

  The polycarbonate polyol includes, for example, (1) a reaction product of a compound having two or more hydroxyl groups such as ethylene glycol and propylene glycol and a carbonate ester, and (2) two or more hydroxyl groups such as ethylene glycol and propylene glycol. And compounds obtained by reacting phosgene with a compound having a phosgene in the presence of an alkali.

  Examples of the carbonic acid ester used in the production method (1) include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and propylene carbonate.

  Known catalysts can be used in synthesizing the polyurethane. Examples of the catalyst include tertiary amine compounds and organometallic compounds.

  Examples of the tertiary amine compound include triethylamine, triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine, 1,8-diazabicyclo- (5,4,0) -undecene-7 (DBU), and the like. It is done.

Examples of the organometallic compound include a tin compound and a non-tin compound.
Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate. , Triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethylhexanoate and the like.

  Non-tin compounds include, for example, titanium-based compounds such as dibutyltitanium dichloride, tetrabutyltitanate, butoxytitanium trichloride, lead-based compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate, 2-ethyl Examples thereof include iron systems such as iron hexanoate and iron acetylacetonate, cobalt systems such as cobalt benzoate and cobalt 2-ethylhexanoate, zinc systems such as zinc naphthenate and zinc 2-ethylhexanoate, and zirconium naphthenate. .

  Polyolefin can be synthesized by a known method of radical polymerization of an ethylenic monomer. The polyolefin may be a homopolymer or a copolymer (copolymer), and is preferably a copolymer (copolymer).

  Examples of the ethylenic monomer include olefins such as ethylene, propylene, n-butene, isobutylene, 2-butene, cyclopentene, and cyclohexene; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, n-hexyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl Vinyl ethers such as vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether; vinyl esters such as vinyl acetate, vinyl caproate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl benzoate, vinyl cyclohexylcarboxylate, etc. Can be mentioned. The ethylenic monomer can be used alone or in combination of two or more.

  Examples of commercially available polyolefins include “Unistall” (manufactured by Mitsui Chemicals), “Auroren” (manufactured by Nippon Paper Chemicals), and the like.

  Resin (A) gives the functional group which can react with a hydroxyl group to resin by a well-known method, for example, and makes it react with the compound (a) which has the heterocyclic ring and hydroxyl group which have a carbon-carbon double bond in the said functional group. Can be synthesized. In the present invention, since it is important to use the resin (A) regardless of the total route, it goes without saying that the present invention is not limited to the following synthesis method.

  The functional group capable of reacting with the hydroxyl group is preferably an isocyanate group, for example.

  Examples of the method of introducing an isocyanate group into the (meth) acrylic resin include a method of using a (meth) acrylic monomer having an isocyanate group as the (meth) acrylic monomer. Examples of the (meth) acrylic monomer having an isocyanate group include 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate. Examples of commercially available monomers include Karenz AOI and Karenz MOI manufactured by Showa Denko.

  As a method for introducing an isocyanate group into the polyester, for example, when a polyester is obtained by reacting a carboxylic acid component and a hydroxyl component, a hydroxyl group component is excessive to obtain a polyester having a terminal hydroxyl group, The method of adding diisocyanate is mentioned.

  As a method for introducing an isocyanate group into polyurethane, for example, when a polyurethane is obtained by reacting an isocyanate compound with a hydroxyl component, a polyurethane having a terminal isocyanate group can be obtained by increasing the amount of the isocyanate compound.

  Examples of the compound (a) having a heterocyclic ring having a carbon-carbon double bond and a hydroxyl group include 2-furanmethanol (2-furylmethanol), 3-furanmethanol, 2-thiophenmethanol, 3-thiophenmethanol, and the like. It is done.

  Examples of the method of incorporating a heterocyclic ring having a carbon-carbon double bond into polyolefin include synthesis by reacting a maleic anhydride-modified polyolefin with a heterocyclic ring having a carbon-carbon double bond and a compound (a) having a hydroxyl group. it can.

  As another method of incorporating a heterocyclic ring having a carbon-carbon double bond into the (meth) acrylic resin, it can be synthesized by copolymerizing a monomer having a furyl group in addition to the (meth) acrylic monomer. This method is excellent in that the reaction process of synthesis can be reduced.

  Examples of the monomer having a furyl group include furfuryl methacrylate, furfuryl vinyl ether, furfuryl allyl ether, and the like. Among these, furfuryl methacrylate is preferable from the viewpoints of monomer stability and polymerizability.

  In the present invention, the weight average molecular weight of the resin (A) is preferably 10,000 to 1,000,000, more preferably 20,000 to 750,000, and still more preferably 30,000 to 500,000. When the weight average molecular weight of the resin (A) is 1,000,000 or less, the coatability of the anchor coating agent is further improved. Moreover, when the weight average molecular weight is 10,000 or more, the peel strength after the moist heat resistance test of the anchor coating agent is further improved.

  In addition, a weight average molecular weight is the value of polystyrene conversion by the gel permeation chromatography (GPC) of resin (A). For example, the temperature of the columns (KF-805L, KF-803L, and KF-802 manufactured by Showa Denko) is 40 ° C., THF is used as an eluent, the flow rate is 0.2 ml / min, detection is RI, sample concentration 0.02%, and polystyrene was used as a standard sample. The weight average molecular weight of the present invention describes the value measured by the above method.

  The amount of the heterocyclic ring having a carbon-carbon double bond in the resin (A) is preferably a functional group equivalent of 50,000 or less, more preferably 40,000 or less, when the entire heterocyclic ring is a functional group, 000 or less is more preferable. When the functional group equivalent is 50,000 or more, the adhesion to the adherend is further improved.

  In the present invention, the functional group equivalent is calculated by [weight average molecular weight of resin (A)] / [number of functional groups of resin (A)]. In other words, it is the weight average molecular weight of the resin (A) per functional group. For example, if the weight average molecular weight is 50,000 and the number of functional groups is 20, this functional group equivalent can be calculated as 2,500. The weight average molecular weight of the resin (A) can be measured by the method described above.

  The glass transition temperature of the resin (A) is preferably -20 to 100 ° C, more preferably 0 to 90 ° C, further preferably 20 to 80 ° C. When the glass transition temperature of the resin (A) is 100 ° C. or lower, the adhesive force to the substrate is further improved. Moreover, when a glass transition temperature becomes -20 degreeC or more, it will be easy to suppress blocking of coating materials.

  The glass transition temperature refers to the glass transition temperature measured by differential scanning calorimetry (DSC) for a resin obtained by drying the resin (A) to have a nonvolatile content of 100%. For example, for the glass transition temperature, an aluminum pan containing a sample weighed about 10 mg and an aluminum pan not containing a sample are set in a DSC apparatus, and this is set to −100 using liquid nitrogen in a nitrogen stream. A rapid cooling treatment is performed until the temperature is increased to 200 ° C. at 20 ° C./min, and a DSC curve is plotted. The slope of the DSC curve on the low temperature side (the DSC curve portion in the temperature region where no transition or reaction occurs in the test piece) is extended to the high temperature side, and the slope of the step change portion of the glass transition is maximized. From the intersection with the tangent drawn at such a point, the extrapolated glass transition start temperature (Tig) can be determined, and this can be determined as the glass transition temperature. The glass transition temperature of this invention has described the value measured by said method.

The resin (A) preferably has a functional group capable of crosslinking with the curing agent (B).
When the functional group is a hydroxyl group, the hydroxyl value of the resin (A) is preferably 0.1 to 100 (mgKOH / g), more preferably 1 to 50 (mgKOH / g), and 2 to 30 (mgKOH / g). Is more preferable. When the hydroxyl value is 100 (mgKOH / g) or less, the adhesion to the substrate is further improved. Moreover, when the hydroxyl value is 0.1 (mgKOH / g) or more, it is easy to suppress a decrease in peel strength after the wet heat test.
When the functional group is a carboxyl group, the acid value of the resin (A) is preferably 0.1 to 100 (mgKOH / g), more preferably 1 to 50 (mgKOH / g), and 2 to 30 (mgKOH). / G) is more preferred. When the acid value is 100 (mgKOH / g) or less, the adhesion to the substrate is further improved. Moreover, when an acid value becomes 0.1 (mgKOH / g) or more, it is easy to suppress the fall of the peeling strength after a wet heat test.

  The curing agent (B) used in the present invention is not limited as long as it is a compound having two or more functional groups that bind (react) to the functional group contained in the resin (A). When the curing agent (B) crosslinks the resin (A), the durability is improved and the adhesion to the substrate is improved.

  For example, when the resin (A) contains a reactive functional group such as a hydroxyl group or a carboxyl group, the curing agent (B) is preferably a compound that reacts with these functional groups. Examples of the curing agent (B) include an isocyanate curing agent, an epoxy curing agent, a metal chelate curing agent, an aziridine curing agent, an oxazoline curing agent, and a carbodiimide curing agent. Among these, an isocyanate curing agent and an epoxy curing agent are preferable, and an isocyanate curing agent is more preferable.

  Isocyanate-based curing agents are diisocyanate compounds such as 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2 , 6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (Cyclohexyl isocyanate), 1,4-bis (isocyanatomethyl) cyclohexane and the like.

  In addition, adducts of the diisocyanate compound and a polyol compound such as trimethylolpropane, a burette of the diisocyanate compound, an isocyanurate of the diisocyanate compound, and an isocyanate compound and a known polyether polyol, polyester polyol, acrylic polyol, Trifunctional or higher functional isocyanate curing agents such as adducts with polybutadiene polyol, polyisoprene polyol and the like can be mentioned. Among these, hexamethylene diisocyanate (HDI) isocyanurate and 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) isocyanurate are preferred.

It is also preferable to use a blocked isocyanate curing agent as the isocyanate curing agent. This further improves the peel strength after the wet heat resistance test.
When the anchor coating agent of the present invention is used for a solar cell protective sheet, the isocyanate compound is preferably a blocked isocyanate compound.

Examples of the blocking agent for the blocked isocyanate curing agent include phenols such as phenol, thiophenol, methylthiophenol, xylenol, cresol, resorcinol, nitrophenol, and chlorophenol; oximes such as acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime; methanol, Ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, t-pentanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, benzyl Alcohols such as alcohol; 3,5-dimethylpyrazole, 1, -Pyrazoles such as pyrazole; triazoles such as 1,2,4-triazole; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; ε-caprolactam, δ-valerolactam, γ-butyrolactam, Examples include lactams such as β-propyl lactam, and active methylene compounds such as methyl acetoacetate, ethyl acetoacetate, acetylacetone, methyl malonate, and ethyl malonate. In addition, amines, imides, mercaptans, imines, ureas, diaryls, and the like are also included. The blocking agents can be used alone or in combination of two or more.
80-150 degreeC is preferable and the dissociation temperature of a blocking agent has more preferable 90-140 degreeC. As the blocking agent, for example, methyl ethyl ketone oxime (dissociation temperature: 140 ° C., the same applies hereinafter), 3,5-dimethylpyrazole (120 ° C.), diisopropylamine (120 ° C.) and the like are more preferable.

  The anchor coating agent of the present invention can further contain particles (organic particles, inorganic particles). By including particles, tackiness of the resin layer can be suppressed. Inorganic particles are preferred because of their improved adhesion to the substrate. Of the inorganic particles, talc, hydrotalcite, mica, and kaolin are more preferable.

  Organic particles include, for example, polymer particles such as polystyrene, nylon (registered trademark) resin, melamine resin, guanamine resin, phenol resin, urea resin, silicon resin, methacrylate resin, acrylate resin; cellulose powder, nitrocellulose powder, wood powder Waste paper powder, rice husk powder, starch and the like.

The polymer particles can be obtained by a polymerization method such as an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a soap-free polymerization method, a seed polymerization method, or a microsuspension polymerization method.
The polymer particles are preferably particles having a melting point or softening point of 150 ° C. or higher. When the melting point or softening point is 150 ° C. or higher, it is difficult to soften with heat during the formation of the resin layer, and thus it is easy to suppress blocking properties.

  Inorganic particles include, for example, oxides of metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, hydroxides thereof, sulfates thereof, carbonates thereof, and silicas thereof. Examples include salts. Inorganic particles include, for example, silica gel, aluminum oxide, calcium hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, zinc oxide, lead oxide, diatomaceous earth, zeolite, aluminosilicate, talc, white carbon, mica, Glass fiber, glass powder, glass beads, clay, wollastonite, iron oxide, antimony oxide, titanium oxide, lithopone, pumice powder, aluminum sulfate, zirconium silicate, barium carbonate, dolomite, molybdenum disulfide, iron sand, carbon black, etc. It is done.

  The particles can be used alone or in combination of two or more.

In addition, a crosslinking accelerator can be further added to the anchor coating agent as long as the problem can be solved. The crosslinking accelerator serves as a catalyst for promoting the reaction between the resin (A) and the curing agent (B). Examples of the crosslinking accelerator include tin compounds, metal salts, bases, and the like. Specifically, tin octylate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, tin chloride, iron octylate, cobalt octylate, zinc naphthenate. , Triethylamine, triethylenediamine and the like.
The crosslinking accelerator can be used alone or in combination of two or more.

In addition, a pigment can be further added to the anchor coating agent as long as the problem can be solved. Examples of the pigment include inorganic pigments and organic pigments.
Examples of the inorganic pigment include carbon black, titanium oxide, and calcium carbonate.
Organic pigments include, for example, insoluble azo pigments such as toluidine red, toluidine maroon, Hansa yellow, benzidine yellow, and pyrazolone red; soluble azo pigments such as lithol red, heliobordeaux, pigment scarlet, and permanent red 2B; alizarin, indanthrone, thioindigo Derivatives from vat dyes such as maroon; Phthalocyanine organic pigments such as phthalocyanine blue and phthalocyanine green; Quinacridone organic pigments such as quinacridone red and quinacridone magenta; Perylene organic pigments such as perylene red and perylene scarlet; Isoindolinone yellow , Isoindolinone organic pigments such as isoindolinone orange; pyranthrone organic pigments such as pyranthrone red and pyranthrone orange, thioindigo organic pigments Condensed azo organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments such as quinophthalone yellow; isoindoline organic pigments such as isoindoline yellow: Other pigments include flavanthrone yellow, acylamide yellow, nickel azo yellow, Examples include copper azomethine yellow, perinone orange, anthrone orange, dianslaquinonyl red, and dioxazine violet.

  When a pigment is used, it is preferable to add a dispersant at the same time. Thereby, the dispersibility of the pigment can be improved, and the storage stability of the anchor coating agent can be improved.

  Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a salt of a long chain polyaminoamide and a polar acid ester, a high molecular weight unsaturated acid ester, Molecular copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalene sulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate salt, polyoxyethylene alkyl phosphate ester, polyoxyethylene nonyl Examples include phenyl ether and stearylamine acetate.

  Moreover, the effect of a heat-and-moisture resistance improvement can be anticipated by adding an epoxy resin (Ep) to the anchor coating agent of this invention. The amount of the epoxy resin added is preferably 0.1 to 70 parts by weight, more preferably 0.5 to 60 parts by weight, and still more preferably 1 to 50 parts by weight with respect to 100 parts of the resin (A).

  Examples of the epoxy resin include glycidyl ether compounds and glycidyl ester compounds.

  Examples of the glycidyl ether compound include bisphenol type epoxy resin, novolac type epoxy resin, biphenol type epoxy resin, bixylenol type epoxy resin, trihydroxyphenylmethane type epoxy resin, tetraphenylolethane type epoxy resin and the like.

  Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin and the like.

  Examples of novolak type epoxy resins include phenol novolak type epoxy resins, cresol novolak type epoxy resins, brominated phenol novolak type epoxy resins, naphthalene skeleton containing phenol novolak type epoxy resins, dicyclopentadiene skeleton containing phenol novolak type epoxy resins, and the like. It is done.

Examples of the glycidyl ester compound include terephthalic acid diglycidyl ester.
Epoxy resins can be used alone or in combination of two or more.

A solvent can be added to the anchor coating agent of the present invention.
Examples of the solvent include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether, and diethylene glycol methyl ether;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone;
Ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether;
Hydrocarbons such as hexane, heptane, octane,
Aromatics such as benzene, toluene, xylene, cumene;
Examples include esters such as ethyl acetate and butyl acetate. Among these, a solvent having a boiling point of 50 ° C to 200 ° C is preferable. When the boiling point is 50 or more, it is easy to form a resin layer having a uniform thickness by coating. Moreover, when the boiling point is 200 ° C. or lower, the drying property at the time of coating is further improved.
The solvent can be used alone or in combination of two or more.

  The anchor coating agent of the present invention includes a filler, a thixotropy imparting agent, an anti-aging agent, an antioxidant, an antistatic agent, a flame retardant, a thermal conductivity improving agent, a plasticizer, an anti-sagging agent, an anti-sticking agent as necessary. Various additives such as a soiling agent, an antiseptic, a disinfectant, an antifoaming agent, a leveling agent, a curing agent, a thickener, a pigment dispersant, and a silane coupling agent may be added.

  The coated product of the present invention includes a base material and a resin layer containing an anchor coat agent. The resin layer can be formed by coating with an anchor coating agent.

  A conventionally known method can be used as a method of applying the anchor coating agent to the substrate. Examples of the coating method (coating apparatus) include comma coating, gravure coating, reverse coating, roll coating, lip coating, and spray coating. It is preferable to perform heat drying during coating.

Examples of the base material include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; olefin films such as polyethylene, polypropylene, and polycyclopentadiene, polyvinyl fluoride, polyvinylidene fluoride film, polytetrafluoroethylene film, ethylene- Fluorine-based films such as tetrafluoroethylene copolymer films; plastic films such as acrylic films and triacetylcellulose films. In addition, it may be applied to a rigid base material (plate material) such as a glass plate. Further, the substrate may have a multilayer structure of two or more layers, and a deposited film in which a metal oxide or a nonmetallic inorganic oxide is deposited may be laminated. Furthermore, the substrate may be transparent or colored.
The thickness of the substrate is usually about 10 to 300 μm.

  The thickness of the resin layer is usually about 0.1 to 30 μm.

  The coated product of the present invention is preferably used as a protective sheet (a front protective sheet or a back protective sheet) that constitutes a solar cell module where there are many embodiments.

  When using it as a protective sheet, for example, when manufacturing a solar cell module, the EVA sheet surface of the solar cell encapsulant and the protective sheet are thermocompression bonded so that they are in close contact with each other. As thermocompression bonding conditions, for example, vacuum degassing is performed at 140 ° C. to 170 ° C. for about 3 to 10 minutes, and then pressure bonding is performed at atmospheric pressure for about 10 to 50 minutes while maintaining the temperature. After thermocompression bonding, if necessary, it may be put into an oven at 100 to 200 ° C. and heated for about 5 to 60 minutes.

Next, the solar cell module will be described.
As shown in the sectional view of FIG. 1, the typical configuration of the solar cell module is that the solar cell surface protection material 1 positioned on the light receiving surface side of the solar cell element 3 is received by the solar cell with respect to the solar cell element 3. It can be obtained by laminating via the sealing material 2 located on the surface side, laminating the protective sheet 5 via the sealing material 4 located on the non-light-receiving surface side of the solar battery cell, and thermocompression bonding.

  Examples of the solar cell surface protective material 1 include glass plates, polycarbonate and polyacrylate plastic plates, and the like.

  The sealing material 2 and the sealing material 4 are preferably EVA, an olefin film, or the like. These sealing materials may contain additives such as an ultraviolet absorber and a light stabilizer for improving weather resistance, and an organic peroxide for crosslinking the sealing material itself.

    Examples of the solar cell element 3 include an element in which an electrode is provided on a photoelectric conversion layer such as a compound semiconductor typified by crystalline silicon, amorphous silicon, or copper indium selenide. The element may be formed on a substrate such as glass.

  The anchor coating agent of the present invention can be used not only for solar cell protective sheet applications but also for improving the peel strength between various adherends and substrates. Specifically, examples of the adherend on which the anchor coating agent of the present invention is considered to improve the peel strength include UV curable printing ink and UV curable hard coating agent.

  The mechanism by which the anchor coating agent of the present invention can improve the peel strength with these adherends is that the resin (A) has radical crosslinkability, so these adherends are radically crosslinked by UV irradiation. It is presumed that the adherend and the anchor coating agent form chemical crosslinks.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example. In the examples, “part” represents “part by weight” and “%” represents “% by weight”.

  The glass transition temperature and the hydroxyl value were measured as follows.

<Measurement of glass transition temperature (Tg)>
The glass transition temperature was measured by the differential scanning calorimetry (DSC) method described above.
In addition, the sample for Tg measurement used the non-volatile part which heated the resin solution to measure at 150 degreeC for about 15 minutes, and was made to dry.

<Measurement of acid value>
About 1 g of a sample (resin solution: about 50%) is accurately weighed in a stoppered Erlenmeyer flask, and 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. To this is added phenolphthalein reagent as an indicator and held for 30 seconds. Thereafter, the solution is titrated with a 0.1N alcoholic potassium hydroxide solution until the solution becomes light red.
The acid value was determined by the following formula. The acid value was a numerical value of the dry state of the resin (unit: mgKOH / g).
Acid value (mgKOH / g) = {(5.611 × a × F) / S} / (Nonvolatile content concentration / 100)
Where S: Amount of sample collected (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1N alcoholic potassium hydroxide solution

<Measurement of hydroxyl value>
About 1 g of a sample is accurately weighed in a stoppered Erlenmeyer flask, and 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. Further, exactly 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride was dissolved in pyridine to make a volume of 100 ml) was added and stirred for about 1 hour. To this, phenolphthalein reagent is added as an indicator and lasts for 30 seconds. Thereafter, the solution is titrated with a 0.5N alcoholic potassium hydroxide solution until the solution becomes light red.
The hydroxyl value was determined by the following formula. The hydroxyl value was a numerical value in the dry state of the resin (unit: mgKOH / g).
Hydroxyl value (mgKOH / g) = [{(ba) × F × 28.05} / S] / (Nonvolatile content concentration / 100) + D
Where S: Amount of sample collected (g)
a: Consumption of 0.5N alcoholic potassium hydroxide solution (ml)
b: Consumption of the 0.5N alcoholic potassium hydroxide solution in the blank experiment (ml)
F: Potency of 0.5N alcoholic potassium hydroxide solution D: Acid value (mgKOH / g)

<Synthesis Example 1 (Meth) acrylic resin A1 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 10 parts of methyl methacrylate, 10 parts of cyclohexyl methacrylate, 71 parts of n-butyl methacrylate, 5 parts of furfuryl methacrylate, 4 parts of 2-hydroxyethyl methacrylate and 0.25 part of azobisisobutyronitrile is added dropwise. The monomer solution was continuously added dropwise over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, the reaction mixture was cooled and the weight average molecular weight was 82,000, the hydroxyl value was 17.0 (mgKOH / g), the acid value was 0 (mgKOH / g), the Tg was 36 ° C., and the functional group equivalent of furyl group was 3323. A (meth) acrylic copolymer A1 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 2 (Meth) acrylic resin A2 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 60 parts of n-butyl methacrylate, 24 parts of t-butyl methacrylate, 10 parts of furfuryl methacrylate, 6 parts of 2-hydroxyethyl methacrylate and 0.5 part of azobisisobutyronitrile was charged into the dropping funnel, The monomer liquid was continuously added dropwise over 2 hours. Subsequently, 0.25 parts of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, the reaction mixture was cooled and the weight average molecular weight was 55,000, the hydroxyl value was 25.9 (mgKOH / g), the acid value was 0 (mgKOH / g), the Tg was 45 ° C., and the functional group equivalent of furyl group was 1662. A (meth) acrylic copolymer A2 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 3 (Meth) acrylic resin A3 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 18 parts of methyl methacrylate, 10 parts of cyclohexyl methacrylate, 40 parts of n-butyl methacrylate, 30 parts of furfuryl methacrylate, 2 parts of 2-hydroxyethyl methacrylate and 0.20 part of azobisisobutyronitrile is added dropwise. The monomer solution was continuously added dropwise over 2 hours. Subsequently, 0.25 parts of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, cooling is performed, the weight average molecular weight is 123,000, the hydroxyl value is 8.9 (mgKOH / g), the acid value is 0 (mgKOH / g), the Tg is 51 ° C., and the functional group equivalent of the furyl group is 554, a (meth) acrylic copolymer A3 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 4 (Meth) acrylic resin A4 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 20 parts of cyclohexyl methacrylate, 20 parts of n-butyl methacrylate, 50 parts of furfuryl methacrylate, 10 parts of 2-hydroxyethyl methacrylate, and 0.20 part of azobisisobutyronitrile is charged into the dropping funnel, and the monomer solution Was continuously added dropwise over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, cooling is performed, the weight average molecular weight is 134,000, the hydroxyl value is 43.4 (mgKOH / g), the acid value is 0 (mgKOH / g), the Tg is 55 ° C., and the functional group equivalent of the furyl group is 332. A (meth) acrylic copolymer A4 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 5 (Meth) acrylic resin A5 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 5 parts of n-butyl methacrylate, 90 parts of furfuryl methacrylate, 5 parts of 2-hydroxyethyl methacrylate, and 0.15 part of azobisisobutyronitrile was charged into the dropping funnel, and the monomer solution was added over 2 hours. Continuous dripping. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, cooling is performed, the weight average molecular weight is 178,000, the hydroxyl value is 22.1 (mgKOH / g), the acid value is 0 (mgKOH / g), the Tg is 57 ° C., and the functional group equivalent of the furyl group is A (meth) acrylic copolymer A5 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 6 (Meth) acrylic resin A6 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 5 parts of methacrylic acid, 10 parts of methyl methacrylate, 10 parts of cyclohexyl methacrylate, 65 parts of n-butyl methacrylate, 10 parts of 2-isocyanatoethyl methacrylate and 0.15 part of azobisisobutyronitrile is added dropwise. The monomer solution was continuously added dropwise over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and further stirred for 1 hour for polymerization. Next, 6.3 parts of furfuryl alcohol and 0.03 part of dibutyltin dilaurate were added, and the mixture was reacted at 40 ° C. with stirring for 2 hours. It was confirmed by IR that the isocyanate peak (2260 cm-1) had disappeared, the weight average molecular weight was 152,000, the hydroxyl value was 0 (mgKOH / g), the acid value was 29.0 (mgKOH / g), and the Tg was 43. A (meth) acrylic copolymer A6 solution having a functional group equivalent of 1650 ° C. and a non-volatile content of 50% was obtained.

<Synthesis Example 7 (Meth) acrylic resin A7 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 10 parts of methyl methacrylate, 15 parts of cyclohexyl methacrylate, 60 parts of n-butyl methacrylate, 15 parts of 2-hydroxyethyl methacrylate, and 0.15 part of azobisisobutyronitrile was charged into the dropping funnel, It was continuously dropped over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and further stirred for 1 hour for polymerization. Next, 25.9 parts of a compound obtained by adding 2-thiophene methanol to the primary isocyanate group of isophorone diisocyanate (molecular weight: 336.46) and 0.03 part of dibutyltin dilaurate were added and reacted at 60 ° C. with stirring for 5 hours. . It was confirmed by IR that the isocyanate peak (2260 cm-1) had disappeared, the weight average molecular weight was 166,000, the hydroxyl value was 17.0 (mgKOH / g), the acid value was 0 (mgKOH / g), and the Tg was 20 A (meth) acrylic copolymer A7 solution having a functional group equivalent of thienyl group of 1638 and a non-volatile content of 50% was obtained.

<Synthesis Example 8 (Meth) acrylic resin A8 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 10 parts of methyl methacrylate, 15 parts of cyclohexyl methacrylate, 60 parts of n-butyl methacrylate, 15 parts of 2-hydroxyethyl methacrylate, and 0.15 part of azobisisobutyronitrile was charged into the dropping funnel, It was continuously dropped over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and further stirred for 1 hour for polymerization. Next, 25.5 parts of a compound obtained by adding 3-pyridinemethanol to the primary isocyanate group of isophorone diisocyanate (molecular weight 331.42) and 0.03 part of dibutyltin dilaurate were added and reacted at 60 ° C. with stirring for 5 hours. . It was confirmed by IR that the isocyanate peak (2260 cm-1) had disappeared, the weight average molecular weight was 181,000, the hydroxyl value was 18.1 (mgKOH / g), the acid value was 0 (mgKOH / g), and the Tg was 23. A (meth) acrylic copolymer A8 solution having a functional group equivalent of pyridyl group of 1633 and a non-volatile content of 50% was obtained.

<Synthesis Example 9 (Meth) acrylic resin A9 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 49.33 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, 5 parts methyl methacrylate, 10 parts cyclohexyl methacrylate, 60 parts n-butyl methacrylate, 19 parts t-butyl methacrylate, 0.34 parts furfuryl methacrylate, 5 parts 2-hydroxyethyl methacrylate, azobisisobutyronitrile. A monomer liquid containing 25 parts was charged into a dropping funnel, and the monomer liquid was continuously dropped over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, cooling is performed, the weight average molecular weight is 78,000, the hydroxyl value is 21.7 (mgKOH / g), the acid value is 0 (mgKOH / g), the Tg is 46 ° C., and the functional group equivalent of the furyl group is A 48551, (meth) acrylic copolymer A9 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 10 (Meth) acrylic resin A21 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer solution containing 10 parts of methyl methacrylate, 16 parts of cyclohexyl methacrylate, 70 parts of n-butyl methacrylate, 2 parts of 2-hydroxyethyl methacrylate, 2 parts of glycidyl methacrylate and 0.15 part of azobisisobutyronitrile is added to the dropping funnel. The monomer liquid was continuously dropped over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and further stirred for 1 hour for polymerization.
Thereafter, 0.8 part of dimethylbenzylamine, 1 part of acrylic acid and a polymerization inhibitor were added, and the mixture was heated and stirred at 100 ° C. for 15 hours. After confirming that the acid value was 2 or less, the system was cooled and the weight average molecular weight was 39,000, the hydroxyl value was 17.2 (mgKOH / g), the acid value was 0 (mgKOH / g), and the Tg was 30 ° C. Thus, a (meth) acrylic copolymer A21 solution having an acryloyl group functional group equivalent of 7278 and a nonvolatile content of 50% was obtained.

<Synthesis Example 11 (Meth) acrylic resin A22 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, 10 parts methyl methacrylate, 20 parts cyclohexyl methacrylate, 25 parts butyl acrylate, 5 parts n-butyl methacrylate, 15 parts t-butyl methacrylate, 20 parts tetrahydrofurfuryl methacrylate, 5 parts 2-hydroxyethyl methacrylate, azobisisobuty A monomer liquid containing 0.30 part of nitrile was charged into a dropping funnel, and the monomer liquid was continuously dropped over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, cooling is performed, the weight average molecular weight is 66,000, the hydroxyl value is 21.0 (mgKOH / g), the acid value is 0 (mgKOH / g), Tg is 32 ° C., the functional group equivalent of the tetrahydrofuryl group Was 851, and a (meth) acrylic copolymer A22 solution having a nonvolatile content of 50% was obtained.

<Synthesis Example 12 (Meth) acrylic resin A23 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, 10 parts of methyl methacrylate, 20 parts of cyclohexyl methacrylate, 25 parts of butyl acrylate, 25 parts of n-butyl methacrylate, 15 parts of t-butyl methacrylate, 5 parts of 2-hydroxyethyl methacrylate, and 0.30 part of azobisisobutyronitrile. The monomer liquid containing was charged into the dropping funnel, and the monomer liquid was continuously dropped over 2 hours. Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. After completion of the reaction, the reaction mixture is cooled, and the weight average molecular weight is 61,000, the hydroxyl value is 23.0 (mgKOH / g), the acid value is 0 (mgKOH / g), Tg is 25 ° C., ) Acrylic copolymer A23 solution was obtained.

<Synthesis Example 13 (Meth) acrylic resin A24 solution>
To a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a dropping layer, 90 parts of water was added and the temperature in the flask was raised to 85 ° C., and then 0.2 part of potassium persulfate was added. . Next, 50 parts of water, 92 parts of n-butyl methacrylate, 8 parts of 2-hydroxyethyl methacrylate, ammonium polyoxyalkylene alkyl ether sulfate (product name: Eleminol CLS-20 [manufactured by Sanyo Chemical Industries Ltd.]) 20% aqueous solution A mixed solution obtained by mixing 1.5 parts and 2 parts of a 25% aqueous solution of polyoxyethylene alkyl ether (product name: Emulgen E1118S-70 [manufactured by Kao Corporation)] was dropped into the flask over 2 hours from the dropping layer. . During the dropping, the temperature in the flask was kept at 80 ° C. After completion of the dropping, the temperature in the flask was kept at 85 ° C. for 30 minutes. Next, the temperature in the flask is cooled to 62 ° C., 1 part of a 5% aqueous solution of t-butyl hydroperoxide and 2 parts of a 1% aqueous solution of sodium isoascorbate are added successively, and the temperature in the flask is kept at 62 ° C. Hold for 30 minutes. Finally, it is cooled to room temperature, adjusted to pH 8 by adding 25% aqueous ammonia, filtered through a nylon mesh, hydroxyl value is 34.4 (mgKOH / g), acid value is 0 (mgKOH / g), A (meth) acrylic copolymer A24 solution having a Tg of 21 ° C. and a nonvolatile content of 40% was obtained. A24 had a molecular weight that was too high to measure the weight average molecular weight.

<Synthesis Example 14 (Meth) acrylic resin A25 solution>
Into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introduction tube were charged 50 parts of toluene and 50 parts of methyl ethyl ketone, and the temperature was raised to 100 ° C. in a nitrogen atmosphere. Next, a monomer liquid containing 86 parts of cyclohexyl methacrylate, 5 parts of butyl acrylate, 9 parts of 2-hydroxyethyl methacrylate, and 0.20 part of azobisisobutyronitrile was charged into the dropping funnel, and the monomer liquid was continuously dropped over 2 hours. . Subsequently, 0.25 part of azobisisobutyronitrile was added to the flask in three portions and added every hour to conduct a polymerization reaction, and the reaction was continued for another hour. Thereafter, 0.03 part of dibutyltin dilaurate was added, and 3.58 parts of 2-isocyanatoethyl methacrylate was added dropwise over 2 hours while stirring at 40 ° C. After confirming the disappearance of the isocyanate peak (2260 cm-1) by IR, cooling was performed, the weight average molecular weight was 122,000, the hydroxyl value was 25.8 (mgKOH / g), and the acid value was 0 (mgKOH / g). Thus, a (meth) acrylic copolymer A25 solution having a Tg of 65 ° C., a functional group equivalent of methacryloyl group of 4493, and a non-volatile content of 50% was obtained.

<Synthesis Example 15 Polyester P1 Solution>
In a polymerization tank of a polymerization reactor equipped with a polymerization tank, a stirrer, a thermometer, a water separator, a reflux condenser, and a nitrogen introduction tube, 31 parts of terephthalic acid, 31 parts of isophthalic acid, 5 parts of adipic acid, 21.5 ethylene glycol Part, 9 parts of neopentyl glycol, 1.5 parts of trimethylolpropane and 1 part of furfuryl alcohol were charged into a polymerization tank and heated to 160 to 240 ° C. while stirring under a nitrogen stream to conduct a transesterification reaction. Next, the polymerization tank was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction under reduced pressure was terminated, the weight average molecular weight was 62,000, the hydroxyl value was 7.2 (mgKOH / g), A polyester polyol having an acid value of 0 (mgKOH / g), a Tg of 28 ° C., and a furyl functional group equivalent of 9810 was obtained. Further, it was diluted with ethyl acetate to obtain a polyester P1 solution having a nonvolatile content of 40%.

<Synthesis Example 16 Polyurethane U1 Solution>
In a four-necked flask equipped with a cooling tube, a nitrogen introducing tube, a stirring device, a thermometer, and a dropping funnel, 130 parts of C-2090 (manufactured by Kuraray Co., Ltd., polycarbonate polyol), 10 parts of 1,6-hexanediol, cyclohexanedimethanol 10 parts, 2 parts of trimethylolpropane, 51 parts of isophorone diisocyanate and 100 parts of toluene were added, 0.03 part of dibutyltin dilaurate was added as a catalyst, the temperature was gradually raised to 100 ° C., and the reaction was carried out for 3 hours. After confirming that there was no NCO peak by IR measurement, 2.85 parts of a compound (molecular weight 320.39) obtained by adding furfuryl alcohol to the primary isocyanate group of isophorone diisocyanate was added and reacted for 4 hours to be added. After confirming again that there is no NCO peak by IR measurement, by adding 106 parts of ethyl acetate and cooling, the number average molecular weight is 39,000, the hydroxyl value is 4.1 (mgKOH / g), the acid value Was 0 (mgKOH / g), Tg was 20 ° C., furyl functional group equivalent was 23162, and a polyurethane U1 solution having a nonvolatile content of 50% was obtained.

  Table 1 shows a list of weight average molecular weights, OH values, Tg, and functional group equivalents of (meth) acrylic resins A1 to A9, polyester P1, polyurethane U1, and (meth) acrylic resins A21 to 23. .

<Isocyanate curing agent solution B1>
An isocyanurate of hexamethylene diisocyanate blocked with MEK oxime and an isocyanurate of hexamethylene diisocyanate blocked with 3,5-dimethylpyrazole in a ratio of 1: 1 were used to obtain a 75% nonvolatile solution. Curing agent solution B1 was obtained.

<Carbodiimide curing agent solution B2>
Carbodilite V-03 (Nisshinbo Chemical Co., Ltd.) was used as a carbodiimide curing agent solution B2.

<Anchor coating agent solution 1>
A solution in which the (meth) acrylic resin A1 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as anchor coating agent solution 1.

<Anchor coating agent solutions 2-5>
Prepare anchor coat agent solutions 2 to 5 in the same manner as anchor coat agent solution 1 except that (meth) acrylic resin A1 of anchor coat agent solution 1 is changed to (meth) acrylic resin A2 to A5 solution. did.

<Anchor coating agent solution 6>
A solution in which the (meth) acrylic resin A6 solution and the carbodiimide curing agent solution B2 were blended so that the molar ratio of carboxyl groups to carbodiimide groups was 1.5 was designated as anchor coating agent solution 6.

<Anchor coating agent solutions 7-9>
The anchor coating agent solutions 7 to 9 are prepared in the same manner as the anchor coating agent solution 1 except that the (meth) acrylic resin A1 of the anchor coating agent solution 1 is changed to the (meth) acrylic resin A7 to A9 solution. did.

<Anchor coating agent solution 10>
A solution in which the polyester P1 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as anchor coating agent solution 10.

<Anchor coating agent solution 11>
A solution in which the polyurethane U1 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as an anchor coating agent solution 11.

<Anchor coating agent solution 12>
A solution in which the (meth) acrylic resin A21 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as anchor coating agent solution 12.

<Anchor coating agent solution 13>
A solution in which the (meth) acrylic resin A22 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as an anchor coating agent solution 13.

<Anchor coating agent solution 14>
A solution in which the (meth) acrylic resin A23 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as the anchor coating agent solution 14.

<Anchor coating agent solution 15>
The ratio of the (meth) acrylic resin A24 solution and Epocross K-2030E (Nippon Shokubai Co., Ltd., Tg 50 ° C., functional group equivalent 556 of the oxazoline group), which is a solution of the oxazoline group-containing polymer, in a nonvolatile content ratio of 2: 1 An anchor coating agent solution 15 was prepared by mixing Imprafix 2794XP (manufactured by Bayer MaterialScience AG), which is an aqueous dispersion of blocked isocyanate, so that the NCO / OH molar ratio was 1.5. .

<Anchor coating agent solution 16>
A solution in which the (meth) acrylic resin A25 solution and the isocyanate curing agent solution B1 were blended so that the NCO / OH molar ratio was 1.5 was designated as the anchor coating agent solution 16.

[Example 1]
Peel strength between anchor coat agent and vinyl acetate-ethylene copolymer film (manufactured by Sunvic, fast type, hereinafter referred to as EVA film), moisture heat resistance test (after 500 hours, using anchor coat agent solution 1) After 1000 hours and 2000 hours), the peel strength was evaluated.

<Peel strength>
The anchor coating agent solution 1 is applied to the corona-treated surface of a 188 μm thick polyester film (Lumirror X10S, manufactured by Toray Industries Inc.) with a gravure coater, and the solvent is dried at 100 ° C. for 1 minute. The coating amount is 3 g / square meter resin layer Was provided. An EVA film and a white glass plate are stacked on the resin layer, and this laminated body is placed on a heat plate of a module laminator PVL0505S (manufactured by Nisshinbo Mechatronics Co., Ltd.) heated to 140 ° C. so that the white plate glass faces downward. It was evacuated to a certain degree and left for 5 minutes. Next, the sample was pressed at atmospheric pressure while maintaining 140 ° C., and allowed to stand for 15 minutes to prepare a measurement sample. The surface of the polyester film was cut into a width of 15 mm with a cutter, and the initial peel strength between the anchor coating agent and the EVA film was measured. For the measurement, a tensile tester was used, and a 180 degree peel test was performed at a load speed of 100 mm / min. The obtained measurement values were evaluated as follows.
◎: 50 N / 15 mm or more Good ○: 30 N / 15 mm or more to less than 50 N / 15 mm Practical range Δ: 10 N / 15 mm or more to less than 30 N / 15 mm Impractical use ×: Less than 10 N / 15 mm Impractical use

<Peel strength after wet heat test>
Separately prepared measurement samples were allowed to stand for 500 hours, 1000 hours, and 2000 hours in an atmosphere of 85 ° C. and 85% relative humidity, respectively, and then the peel strength after the wet heat resistance test was measured. The evaluation criteria are the same as described above.

[Examples 2 to 11, Comparative Examples 1 to 4]
The anchor coating agent solutions 2 to 15 were evaluated in the same manner as in Example 1 to give Examples 2 to 11 and Comparative Examples 1 to 4, respectively.

  Since Examples 1-11 use the anchor coat agent containing resin and the hardening agent in which the resin contains the heterocyclic ring which has a carbon-carbon double bond, it is in the initial peeling strength and the peeling strength after a heat-and-moisture resistance test. It turns out that it is excellent.

  Comparative Example 1 uses (meth) acrylic resin A21, which is a resin having an acryloyl group, and an anchor coating agent containing a curing agent. Since the (meth) acrylic resin A21 uses a large amount of a polymerization inhibitor for the purpose of preventing gelation during the preparation of the solution, the adhesion between the anchor coating agent and the EVA film is inhibited, and the peel strength is inferior.

  Comparative Example 2 uses an anchor coat agent containing a resin having a tetrahydrofuryl group and a curing agent. Although the tetrahydrofuryl group has a heterocyclic structure, since the heterocyclic ring does not have a carbon-carbon double bond, the peel strength is inferior.

  Comparative Example 3 uses an anchor coating agent containing a resin and a curing agent, but the resin does not contain a heterocyclic ring having a carbon-carbon double bond, so that the peel strength is inferior.

  In Comparative Example 4, an anchor coat agent containing a resin having an oxazoline group and a curing agent is used. Although the oxazoline group has a heterocyclic structure, since the heterocyclic ring does not have a carbon-carbon double bond, the peel strength is inferior.

  <Storage stability>

[Example 21]
The storage stability was evaluated by the peel strength of the anchor coating solution. An anchor coating agent solution 1 is applied to a corona-treated surface of a polyester film (Lumirror X10S, manufactured by Toray Industries, Inc.) having a thickness of 188 μm with a gravure coater, and dried at 100 ° C. for 1 minute to form a resin layer having a coating amount of 3 g / square meter. Provided. After leaving this polyester film with a resin layer for 3 months in a 60 degreeC thermostat, peel strength was measured similarly to the above. The evaluation criteria are as follows.
◎: 50 N / 15 mm or more Good ○: 30 N / 15 mm or more to less than 50 N / 15 mm Practical range Δ: 10 N / 15 mm or more to less than 30 N / 15 mm Impractical use ×: Less than 10 N / 15 mm Impractical use

[Examples 22 to 31]
It implemented similarly to Example 21 except having changed the anchor coating agent solution 1 of Example 21 into the anchor coating agent solution 2-11 solution, and was set as Examples 22-31, respectively.

[Comparative Example 5]
The same procedure as in Example 21 was performed except that the anchor coating agent solution 1 was changed to the anchor coating agent solution 16 in Example 21 to obtain Comparative Example 5.

  Table 3 shows the results of Examples 21 to 31 and Comparative Example 5.

  It can be seen that Examples 21 to 31 have high peel strength and excellent storage stability even after being left at 60 ° C. for 3 months. On the other hand, Comparative Example 5 was altered by storage at 60 ° C. for 3 months, and the peel strength decreased.

[Adhesion test of UV curable printing ink]

[Example 41]
The adhesion was evaluated as follows. On the corona-treated surface of a 188 μm thick transparent polyester film (Merinex S Teijin DuPont Films Co., Ltd.), the anchor coating agent solution 1 is applied with a gravure coater, and the solvent is dried at 100 ° C. for 1 minute. The resin layer was provided. On this resin layer, a UV curable printing ink manufactured by Toyo Ink Co., Ltd. was printed using an RI tester (simple color developing device) to a thickness of 5 μm, and a 112 W / cm air-cooled metal halide lamp (Corporation) Using Toshiba), the ink layer was cured by irradiating ultraviolet rays at a predetermined irradiation amount. A test sample having 100 independent chips of about 1 cm in length and 1 cm in width was prepared using a cutter in accordance with JIS K 5600-5-6 for the adhesion between the ink layer and the resin layer. It was tested whether each chip | tip peeled using the cellophane tape on the said test sample. Evaluation was performed according to the following criteria.
◎: Residual rate of chip on test sample 100% Good ○: Residual rate of chip on test sample less than 100% 80% or more Practical range Δ: Residual rate of chip on test sample less than 80 50% or more Impractical ×: Residual rate of chip on test sample is less than 50%

[Examples 42 to 45]
Except having changed the anchor coating agent solution 1 into the anchor coating agent solutions 2-5 in Example 41, it implemented similarly to Example 41 and was set as Examples 42-45.

[Comparative Example 6]
The same procedure as in Example 41 was performed except that the anchor coating agent solution 1 was changed to the anchor coating agent solution 12 in Example 41 to obtain Comparative Example 6.

[Comparative Example 7]
The same procedure as in Example 41 was performed except that the anchor coating agent solution 1 was changed to the anchor coating agent solution 14 in Example 41, and Comparative Example 7 was obtained.

[Comparative Example 8]
Comparative Example 8 was carried out in the same manner as in Example 41 except that the anchor coating agent solution 1 of Example 41 was not used, and the UV curable printing ink I1 was directly printed on the corona-treated surface of the transparent polyester film. It was.

  Table 4 shows the results of Examples 41 to 45 and Comparative Examples 6 to 8.

  From the results in Table 4, in Examples 41 to 45, the adhesion of the ink layer was improved. On the other hand, since Comparative Example 6 contained a large amount of a polymerization inhibitor for the purpose of preventing gelation, the adhesion was low. Moreover, since the comparative example 7 did not contain resin (A), adhesiveness was low. Moreover, since the comparative example 8 did not use an anchor coat agent, adhesiveness is low.

[Adhesion test of UV curable hard coat agent]

[Example 51]
On the corona-treated surface of Melinex S (manufactured by Teijin DuPont Films), a transparent polyester film with a thickness of 188 μm, the anchor coating agent solution 1 is applied with a gravure coater, and the solvent is dried at 100 ° C. for 1 minute. / A square meter resin layer was provided. On this resin layer, a UV curable hard coating agent manufactured by Toyo Ink Co., Ltd. was applied using a Mayer bar so that the thickness was 5 μm after drying, the solvent was dried in an oven, and then 400 mJ / cm with a metal halide lamp. ^The coating layer was formed by irradiating the ultraviolet ray ² . The adhesion test of this coat layer was performed in the same manner as described above, and evaluated according to the same criteria as described above.

[Examples 52 to 55]
Except having changed the anchor coating agent solution 1 into the anchor coating agent solutions 2-5 in Example 51, it implemented similarly to Example 51 and was set as Examples 52-55.

[Comparative Example 9]
The same operation as in Example 51 was performed except that the anchor coating agent solution 1 was changed to the anchor coating agent solution 12 in Example 51, and Comparative Example 9 was obtained.

[Comparative Example 10]
The same operation as in Example 51 was performed except that the anchor coating agent solution 1 was changed to the anchor coating agent solution 14 in Example 51, and Comparative Example 10 was obtained.

[Comparative Example 11]
In Example 51, the same procedure as in Example 51 was performed except that the anchor coating agent solution 1 was not used and the UV curable hard coating agent was directly printed on the corona-treated surface of the transparent polyester film. Comparative Example It was set to 11.

  Table 5 shows the results of Examples 51 to 55 and Comparative Examples 9 to 11.

  From the results in Table 5, Examples 51 to 55 had good adhesion. Moreover, since Comparative Example 6 contains a large amount of a polymerization inhibitor for the purpose of preventing gelation, the adhesion between the resin layer and the coat layer is low. Moreover, since the comparative example 7 does not contain resin (A), adhesiveness is low. Moreover, since the comparative example 8 did not use an anchor coat agent, adhesiveness is low.

DESCRIPTION OF SYMBOLS 1 Solar cell surface protective material 2 Sealing material 3 Solar cell element 4 Sealing material 5 Protective sheet

Claims (2)

Including a heterocyclic ring-containing resin (A) and a curing agent (B),
An anchor coating agent for a solar cell protective sheet, wherein the heterocyclic ring has a carbon-carbon double bond.   The solar cell protective sheet provided with the base material and the resin layer containing the anchor coating agent for solar cell protective sheets of Claim 1.

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