JP7128749B2 - Laminates and solar modules - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laminate and a solar cell module, and more particularly to a laminate and a solar cell module comprising the laminate.

A solar cell module usually includes a surface layer, a sealing material layer that seals the solar cells, and a backsheet.

An ethylene-vinyl acetate copolymer (EVA) film is used as the sealing material layer, but from the viewpoint of improving moisture resistance, durability, and power generation efficiency, an olefin-based sealing material is being studied.

As such an olefin-based sealing material, for example, a solar cell formed from a thermoplastic resin composition containing a propylene-based polymer and a copolymer of propylene and an α-olefin having 2 to 20 carbon atoms excluding propylene. A sealing sheet is known (see, for example, Patent Document 1).

It is known that such a solar cell encapsulant sheet is adhered to the PET film in the backsheet with a urethane-based adhesive (two-liquid type adhesive).

JP 2012-229445 A

On the other hand, solar cell modules are required to have moisture resistance and heat resistance because they are exposed outdoors for a long period of time.

However, when the solar cell encapsulant sheet of Patent Document 1 and the PET film are adhered with a urethane-based adhesive (two-component adhesive), the moisture resistance and heat resistance are poor, so long-term outdoor exposure , there is a problem that the sheet for solar cell encapsulation and the PET film are separated.

An object of the present invention is to provide a laminate for manufacturing a solar cell module excellent in moisture resistance and heat resistance, and a solar cell module comprising the laminate.

The present invention [1] comprises a sealing material layer and a protective resin layer in this order, and the protective resin layer is a cured product of a curable composition containing a blocked isocyanate, a curable functional group-containing fluoropolymer, and an alkoxysilane. and the blocked isocyanate includes a blocked isocyanate in which the isocyanate group of the isocyanate compound is blocked by a blocking agent having an O=C-CH-C=O skeleton, and the sealing material layer contains an olefin-based sealing material. It is a laminate containing.

The present invention [2] includes the laminate according to [1] above, wherein the maximum delamination strength between the sealing material layer and the protective resin layer is 50 N/10 mm or more.

The present invention [3] is the laminate according to the above [1] or [2], wherein the retention rate of the maximum delamination strength between the sealing material layer and the protective resin layer after a pressure cooker test is 15% or more. contains the body.

The present invention [4] provides the laminate according to any one of [1] to [3] above, a solar cell sealed in the laminate, a base material arranged on one side of the laminate, and and a surface layer disposed on the other side of the laminate.

The laminate of the present invention comprises a protective resin layer which is a cured product of a curable composition containing a blocked isocyanate, a curable functional group-containing fluoropolymer, and an alkoxysilane, and a sealing material layer containing an olefin-based sealing material. Prepare.

Therefore, a solar cell module obtained using this laminate is excellent in moisture resistance and heat resistance.

A solar cell module of the present invention includes the laminate of the present invention. Therefore, this solar cell module is excellent in moisture resistance and heat resistance.

FIG. 1 is a schematic configuration diagram showing one embodiment of the laminate of the present invention. 2A and 2B are schematic configuration diagrams showing a method for manufacturing a laminate and a solar cell module. FIG. 2A shows a step of preparing a surface layer, and FIG. FIG. 2(C) shows a step of placing a solar cell on a first encapsulant layer, and FIG. 1 shows the step of laminating the sealing material layer, FIG. 2(E) shows the step of laminating the protective resin layer on the base material, and FIG. 2(F) shows the sealing material laminated on the surface of the surface layer A step of laminating a protective resin layer on the surface of the sealing material layer so that the layer and the protective resin layer laminated on the surface of the base material are in contact, and FIG. 1 shows a process of manufacturing a laminate and a solar cell module by pressing a base material and a surface layer and thermo-compressing them. 3A and 3B are schematic configuration diagrams showing a method for manufacturing a laminate and a solar cell module type laminate in Example 1. FIG. 3A shows a step of laminating a protective resin layer on the surface of a PET film. 3B shows a step of laminating the sealing material layer on the glass substrate, and FIG. 3C shows the sealing material layer laminated on the surface of the glass substrate and the surface of the PET film FIG. 3D shows a step of laminating the protective resin layer on the surface of the sealing material layer so that the protective resin layer is in contact with the protective resin layer, and FIG. 1 shows a process of manufacturing a laminate and a solar cell module type laminate by pressing and thermocompression bonding.

In FIG. 1, a laminate 1 includes a sealing material layer 2 and a protective resin layer 3 in this order.

The laminate 1 is one member of a solar cell module 6 (described later).

That is, the laminate 1 is a laminate for a solar cell module.

The encapsulating material layer 2 extends along the surface direction (direction perpendicular to the thickness direction) and has a substantially flat plate shape with a flat front surface and a flat rear surface.

Further, the encapsulant layer 2 is a encapsulating layer for encapsulating the solar cells 7. Specifically, the encapsulant layer 2 has a thickness of the encapsulant layer 2 It is formed so as to be sealed in the directional center portion. In the following description, the thickness direction lower portion of the sealing material layer 2 (surface layer 5 (described later) side portion) is referred to as a first sealing material layer 8, and the thickness direction upper portion of the sealing material layer 2 ( The protective resin layer 3 side portion) may be referred to as a second sealing material layer 9 . Moreover, there is no boundary between the first sealing material layer 8 and the second sealing material layer 9 , and they are integrally formed as the sealing material layer 2 .

A known solar cell is adopted as the solar cell 7, and electrodes are formed on both sides of a semiconductor substrate such as a silicon wafer, for example.

The encapsulant layer 2 contains an olefin-based encapsulant.

Since the encapsulant layer 2 contains an olefin-based encapsulant, the solar cell module 6 (described later) obtained using the laminate 1 having such an encapsulant layer 2 has the encapsulant layer 2 and the base. Excellent adhesiveness with the material 4 (described later), and excellent moisture resistance and heat resistance.

The olefin-based sealing material is formed from an olefin polymer.

Examples of olefin polymers include olefin homopolymers and olefin copolymers.

Examples of olefin homopolymers include ethylene homopolymers and propylene homopolymers.

Examples of olefin copolymers include ethylene-α-olefin copolymers, propylene-α-olefin copolymers, and propylene-ethylene-α-olefin copolymers.

Ethylene-α-olefin copolymers are copolymers of ethylene and α-olefins (excluding ethylene).

Examples of α-olefins include α-olefins having 2 to 3 carbon atoms such as ethylene and propylene, such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, α-olefins having 4 to 20 carbon atoms such as 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene, preferably α-olefins having 4 to 20 carbon atoms; , and more preferably 1-butene.

Examples of copolymers include random copolymers and block copolymers.

In the ethylene-α-olefin copolymer, the ethylene content is, for example, 40 mol% or more and 70 mol% or less, and the α-olefin content is, for example, 30 mol% or more and 60 mol% or less.

A propylene-α-olefin copolymer is a copolymer of propylene and the above-mentioned α-olefins (excluding propylene).

In the propylene-α-olefin copolymer, the propylene content is, for example, 40 mol% or more and 70 mol% or less, and the α-olefin content is, for example, 30 mol% or more and 60 mol% or less.

A propylene-ethylene-α-olefin copolymer is a copolymer of propylene and ethylene with the above α-olefin.

In the propylene-ethylene-α-olefin copolymer, the propylene content is, for example, 45 mol% or more and 89 mol% or less, the ethylene content is, for example, 10 mol% or more and 25 mol% or less, and the α-olefin content is, for example, 1 mol % or more and 30 mol % or less.

In addition, such olefin copolymers have an isotactic structure, a syndiotactic structure and an atactic structure.

The olefin polymer can be used alone or in combination of two or more. Preferably, a propylene-ethylene-α-olefin copolymer having an isotactic structure and a propylene-ethylene-α-olefin copolymer having an atactic structure are used. used in combination with a polymer.

When a propylene-ethylene-α-olefin copolymer having an isotactic structure and a propylene-ethylene-α-olefin copolymer having an atactic structure are used in combination, the propylene-ethylene- The ratio of the propylene-ethylene-α-olefin copolymer having an isotactic structure to 100 parts by mass of the total amount of the α-olefin copolymer and the propylene-ethylene-α-olefin copolymer having an atactic structure is , for example, 10 parts by mass or more and, for example, 40 parts by mass or less, and the blending ratio of the propylene-ethylene-α-olefin copolymer having an atactic structure is, for example, 60 parts by mass or more. , or, for example, 90 parts by mass or less.

Then, a sealing material composition (described later) containing such an olefin-based sealing material is prepared by the method described later, and the sealing material layer 2 is obtained by molding it.

The protective resin layer 3 extends in the plane direction (direction orthogonal to the thickness direction) and has a substantially flat plate shape with a flat front surface and a flat back surface.

In addition, the protective resin layer 3 is interposed between the sealing material layer 2 and the base material 4 (described later) and is provided to protect the sealing material layer 2. It is formed from a cured product of a curable composition containing alkoxysilane.

A blocked isocyanate is a curing agent for a curable functional group-containing fluoropolymer (that is, a curing agent mainly composed of a curable functional group-containing fluoropolymer), and is a reaction product of an isocyanate compound and a blocking agent (described later). .

Examples of isocyanate compounds include polyisocyanate monomers such as aromatic polyisocyanates, araliphatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.

Examples of aromatic polyisocyanates include tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate or mixtures thereof) (TDI), phenylene diisocyanate (m-, p-phenylene diisocyanate or mixtures thereof), 4, 4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate (NDI), diphenylmethane diisocyanate (4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate or mixtures thereof) (MDI), aromatic diisocyanates such as 4,4'-toluidine diisocyanate (TODI) and 4,4'-diphenylether diisocyanate;

Examples of araliphatic polyisocyanates include xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or mixtures thereof) (XDI), tetramethylxylylene diisocyanate (1,3- or 1,4-tetra araliphatic diisocyanates such as methylxylylene diisocyanate (or mixtures thereof) (TMXDI), ω,ω'-diisocyanate-1,4-diethylbenzene, and the like.

Examples of aliphatic polyisocyanates include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), 1 ,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methylcapate, and other fatty acids group diisocyanates, and the like.

Alicyclic polyisocyanates include, for example, 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanatomethyl-3 ,5,5-trimethylcyclohexylisocyanate (isophorodiisocyanate) (IPDI), methylenebis(cyclohexylisocyanate) (4,4′-, 2,4′- or 2,2′-methylenebis(cyclohexylisocyanate), these Trans, Trans -, Trans, Cis-, Cis, Cis-, or mixtures thereof)) (H ₁₂ MDI), methylcyclohexane diisocyanate (methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate), 1 ,3- or 1,4-bis(isocyanatomethyl)cyclohexane or mixtures thereof (H ₆ XDI), norbornane diisocyanate (various isomers or mixtures thereof) (NBDI).

These polyisocyanate monomers can be used singly or in combination of two or more.

Moreover, as an isocyanate compound, a polyisocyanate derivative other than an above-described polyisocyanate monomer is mentioned.

Polyisocyanate derivatives include, for example, multimers (e.g., dimers, trimers (e.g., isocyanurate derivatives, iminooxadiazinedione derivatives), pentamers, and heptamers of the above-described polyisocyanate monomers. etc.), allophanate derivatives (e.g., allophanate derivatives produced by reaction of the above-described polyisocyanate monomers with known low-molecular-weight polyols), polyol derivatives (e.g., polyisocyanate monomers and known low-molecular-weight polyols and Polyol derivatives (alcohol adducts) produced by the reaction of), biuret derivatives (for example, the above-mentioned polyisocyanate monomers, biuret derivatives produced by reaction with water or amines, etc.), urea derivatives (for example, the above urea derivatives produced by the reaction of polyisocyanate monomers and diamines, etc.), oxadiazinetrione derivatives (for example, oxadiazinetriones produced by the reaction of the above polyisocyanate monomers and carbon dioxide), Examples thereof include carbodiimide derivatives (such as carbodiimide derivatives produced by the decarboxylation condensation reaction of the polyisocyanate monomer described above), uretdione derivatives, and uretonimine derivatives. Furthermore, polyisocyanate derivatives include polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI) and the like.

These polyisocyanate derivatives can be used alone or in combination of two or more.

The isocyanate compound preferably includes polyisocyanate derivatives, more preferably derivatives of alicyclic diisocyanates, and still more preferably isocyanurate derivatives of 1,3-bis(isocyanatomethyl)cyclohexane.

The blocking agent contains, as an essential component, a blocking agent having an O═C—CH—C═O skeleton. The O=C-CH-C=O skeleton represents an active methylene skeleton and/or an active methine skeleton.

When a blocking agent having an O═C—CH—C═O skeleton is used, a solar cell module (described later) obtained using this laminate is excellent in moisture resistance and heat resistance.

Examples of the blocking agent having an O=C-CH-C=O skeleton include active methylene compounds and active methine compounds. Specific examples include dialkyl malonate (e.g., dimethyl malonate, malon diethyl acid, dipropyl malonate, di-n-butyl malonate, di-t-butyl malonate, di-2-ethylhexyl malonate, methyl n-butyl malonate, ethyl n-butyl malonate, methyl s-butyl malonate, ethyl s-butyl malonate, methyl t-butyl malonate, ethyl t-butyl malonate, diethyl methylmalonate, dibenzyl malonate, diphenyl malonate, benzylmethyl malonate, ethylphenyl malonate, t-butylphenyl malonate , isopropylidenemalonate, etc.), malonic acid ester derivatives such as monosubstituted malonic acid esters (e.g., ethyl methylmalonate, ethyl ethylmalonate, etc.), for example, alkyl acetoacetates (e.g., methyl acetoacetate, ethyl acetoacetate, acetoacetate derivatives such as n-propyl acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate, t-butyl acetoacetate, benzyl acetoacetate, phenyl acetoacetate, etc., such as 2-acetoacetoxyethyl methacrylate, acetylacetone, cyano Ethyl acetate, Meldrum's acid and the like can be mentioned.

These blocking agents having an O═C—CH—C═O skeleton can be used alone or in combination of two or more.

The blocking agent having an O═C—CH—C═O skeleton is preferably a malonic acid ester derivative, more preferably a dialkyl malonate, and still more preferably an ethyl malonate.

In addition, the blocking agent can contain, as an optional component, a blocking agent that does not have an O═C—CH—C═O skeleton.

Blocking agents having no O═C—CH—C═O skeleton include, for example, imidazole compounds, imidazoline compounds, pyrimidine compounds, guanidine compounds, alcohol compounds, phenol compounds, amine compounds, and imine compounds. compounds, oxime-based compounds, carbamic acid-based compounds, urea-based compounds, acid amide-based (lactam-based) compounds, acid imide-based compounds, triazole-based compounds, pyrazole-based compounds, mercaptan-based compounds, bisulfites, and the like.

These blocking agents having no O═C—CH—C═O skeleton can be used alone or in combination of two or more.

The content of the blocking agent having no O=C-CH-C=O skeleton is, for example, 80% by mass or less, preferably 50% by mass or less, more preferably 20% by mass, relative to the total amount of the blocking agent. Below, more preferably 10% by mass or less, particularly preferably 5% by mass or less, and usually 0% by mass or more. The content of the blocking agent having an O=C-CH-C=O skeleton is, for example, 20% by mass or more, preferably 50% by mass or more, more preferably 80% by mass, relative to the total amount of the blocking agent. % or more, more preferably 90 mass % or more, particularly preferably 95 mass % or more, and usually 100 mass % or less.

The blocking agent preferably does not contain a blocking agent that does not have an O═C—CH—C═O skeleton, and contains only a blocking agent that has an O═C—CH—C═O skeleton.

By reacting the isocyanate compound and the blocking agent, a blocked isocyanate is obtained as a reaction product of the isocyanate compound and the blocking agent.

As the blending ratio of the isocyanate compound and the blocking agent, the equivalent ratio (active group/isocyanate group) of the active group that reacts with the isocyanate group in the blocking agent (that is, the blocking group) to the isocyanate group of the isocyanate compound is For example, 0.2 or more, preferably 0.5 or more, more preferably 0.8 or more, still more preferably 1.0 or more, for example 1.5 or less, preferably 1.2 or less, more preferably is less than or equal to 1.1.

The reaction conditions are, for example, atmospheric pressure, an inert gas (e.g., nitrogen gas, argon gas, etc.) atmosphere, and a reaction temperature of, for example, 0° C. or higher, preferably 20° C. or higher. 100° C. or lower, preferably 80° C. or lower, more preferably 70° C. or lower. Also, the reaction time is, for example, 0.5 hours or longer, preferably 1.0 hours or longer, and for example, 24 hours or shorter, preferably 12 hours or shorter.

The completion of the reaction can be determined, for example, by confirming the disappearance or reduction of the isocyanate group using infrared spectroscopy.

Further, each of the above reactions may be carried out in the absence of a solvent or, for example, in the presence of a solvent.

Examples of solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; nitriles such as acetonitrile; alkyl esters such as methyl acetate, ethyl acetate, butyl acetate and isobutyl acetate; , n-heptane, octane and other aliphatic hydrocarbons, for example, cyclohexane, methylcyclohexane and other alicyclic hydrocarbons, for example, toluene, xylene, ethylbenzene and other aromatic hydrocarbons, for example, methyl cellosolve acetate, Glycol ether esters such as ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate , ethers such as diethyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether; Halogenated aliphatic hydrocarbons such as carbon chloride, methyl bromide, methylene iodide, and dichloroethane, such as N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethylsulfoxide, hexamethylphosphonylamide, etc. Polar aprotons, further propylene glycol 1-monomethyl ether 2-acetate and the like. These solvents can be used alone or in combination of two or more.

Moreover, in each of the above reactions, a blocked catalyst can be added, if necessary.

Examples of blocked catalysts include basic compounds, and specific examples include alkali metal alcoholates such as sodium methylate, sodium ethylate, sodium phenolate, potassium methylate, tetramethylammonium, Hydroxides of tetraalkylammonium such as tetraethylammonium, tetrabutylammonium, acetates such as tetraalkylammonium, weak organic acid salts such as octylate, myristate, benzoate such as acetic acid, caproic acid, octyl acids, alkali metal salts of alkylcarboxylic acids such as myristic acid, metal salts of the above alkylcarboxylic acids such as tin, zinc, and lead; aminosilyl group-containing compounds such as hexamethylenedisilazane; Hydroxides of alkali metals such as potassium are included. Moreover, these blocked catalysts can also be used as a solution dissolved in the above-described solvent, if necessary.

These blocked catalysts can be used alone or in combination of two or more.

Blocked catalysts preferably include alkali metal alcoholates, more preferably sodium methylate.

The blending ratio of the blocking catalyst is not particularly limited, but for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass with respect to 100 parts by mass of the isocyanate compound. It is 5 parts by mass or more, preferably 3 parts by mass or less, and more preferably 2 parts by mass or less.

Moreover, such blocked isocyanate is obtained, for example, as a non-water-dispersible blocked isocyanate, and can be used, for example, by dissolving it in the above-described solvent.

When the blocked isocyanate is dissolved in a solvent, the solid content concentration is, for example, 1% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and for example, 95% by mass or less, preferably is 90% by mass or less.

Then, by reacting the isocyanate compound with the blocking agent as described above, the isocyanate group of the isocyanate compound is blocked by the blocking group of the blocking agent to obtain the blocked isocyanate.

Since the isocyanate group of such a blocked isocyanate is blocked by a blocking agent, an excellent pot life can be ensured by using it as a curing agent in a curable composition.

The content of the blocked isocyanate in the curable composition is appropriately adjusted so as to fall within the range described below.

The curable functional group-containing fluoropolymer is a fluoropolymer containing a blocked isocyanate as a curing agent and having a functional group (curable functional group) that cures the curable composition.

A curable functional group is a functional group that has activity toward a blocking agent that has blocked isocyanate groups and/or has activity toward isocyanate groups.

Specific examples of the curable functional group include, for example, hydroxyl group (excluding hydroxyl group contained in carboxyl group (hereinafter the same)), carboxyl group, -COOCO- group, cyano group, amino group, glycidyl group, silyl groups, silanate groups, isocyanate groups, and the like. These curable functional groups can be used alone or in combination of two or more.

From the viewpoint of curing reactivity, the curable functional group preferably includes a hydroxyl group, a carboxyl group, -COOCO- group, a cyano group, an amino group and a silyl group, more preferably a hydroxyl group, a carboxyl group, an amino group, Examples include silyl groups, more preferably hydroxyl groups and carboxyl groups from the viewpoint of availability, and particularly preferably hydroxyl groups.

The curable functional group-containing fluoropolymer is, for example, a fluorine-containing monomer capable of forming a fluoropolymer by homopolymerization (hereinafter referred to as a fluorine-containing-polymerizable monomer), and its fluorine-containing-polymerizable It is a copolymer with a monomer that can be copolymerized with a monomer and that contains the above curable functional group (hereinafter referred to as a curable functional group-containing copolymerizable monomer).

In other words, in the curable functional group-containing fluoropolymer, a fluoropolymer (base polymer) obtained by polymerization of a fluorine-containing polymerizable monomer is subjected to curing derived from a curable functional group-containing copolymerizable monomer. functional groups are introduced.

Examples of fluorine-containing polymerizable monomers include tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), vinylidene fluoride (VdF), vinyl fluoride (VF), and (meth)acrylic acid fluoroalkyl ester. (AFAE), fluorovinyl ether, hexafluoropropylene (HFP), perfluoro(alkyl vinyl ether) (PAVE), and the like.

These fluorine-containing polymerizable monomers can be used alone or in combination of two or more.

Preferred fluorine-containing polymerizable monomers include tetrafluoroethylene, chlorotrifluoroethylene and vinylidene fluoride, more preferably tetrafluoroethylene and chlorotrifluoroethylene.

Curable functional group-containing copolymerizable monomers include, for example, hydroxyl group-containing copolymerizable monomers, carboxyl group-containing copolymerizable monomers, -COOCO-group-containing copolymerizable monomers , cyano group-containing copolymerizable monomer, amino group-containing copolymerizable monomer, glycidyl group-containing copolymerizable monomer, silyl group-containing copolymerizable monomer, silanate group-containing copolymer Polymerizable monomers, isocyanate group-containing copolymerizable monomers and the like, preferably hydroxyl group-containing copolymerizable monomers, carboxyl group-containing copolymerizable monomers, amino group-containing copolymerizable monomers, Examples include polymerizable monomers and silyl group-containing copolymerizable monomers.

Examples of hydroxyl group-containing copolymerizable monomers 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-containing vinyl ethers such as hydroxy-2-methylbutyl vinyl ether, 5-hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether, and hydroxyl-containing vinyl ethers such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether and glycerol monoallyl ether Allyl ethers, for example, hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

These hydroxyl group-containing copolymerizable monomers can be used alone or in combination of two or more.

From the viewpoint of polymerization reactivity and reaction curability, the hydroxyl group-containing copolymerizable monomer preferably includes hydroxyl group-containing vinyl ethers, more preferably 4-hydroxybutyl vinyl ether and 2-hydroxyethyl vinyl ether.

Carboxyl group-containing copolymerizable monomers include, for example, acrylic acid, methacrylic acid, vinylacetic acid, crotonic acid, cinnamic acid, 3-allyloxypropionic acid, 3-(2-allyloxyethoxycarbonyl)propionic acid, Itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, maleic anhydride, fumaric acid, fumaric acid monoester, vinyl phthalate, vinyl pyromellitic acid, 3-(2-allyloxyethoxycarbonyl)propionic acid , 3-(2-allyloxybutoxycarbonyl)propionic acid, 3-(2-vinyloxyethoxycarbonyl)propionic acid, 3-(2-vinyloxybutoxycarbonyl)propionic acid and the like.

These carboxyl group-containing copolymerizable monomers can be used alone or in combination of two or more.

As the carboxyl group-containing copolymerizable monomer, crotonic acid, itaconic acid, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, and 3-allyl are preferred from the viewpoint of suppressing the formation of homopolymers. Oxypropionic acid can be mentioned.

Examples of amino group-containing copolymerizable monomers include amino vinyl ethers represented by CH ₂ ═CH—O—(CH ₂ ) _x —NH ₂ (x=0 to 10), such as CH ₂ ═CH Allylamines represented by —O—CO(CH ₂ ) _x —NH ₂ (x=1 to 10), such as aminomethylstyrene, vinylamine, acrylamide, vinylacetamide and vinylformamide.

These amino group-containing copolymerizable monomers can be used alone or in combination of two or more.

Silyl group-containing copolymerizable monomers include, for example, silicone vinyl monomers. Examples of silicone-based vinyl monomers include _CH2 =CHCO2( _CH2 )3Si(OCH3) _{3 , CH2} = _{CHCO2 ( CH2} )3Si _{( OC2H5} ) _{3 , CH2 =} C( _CH3 ) _CO2 ( _CH2 )3Si(OCH3) ₃ , _CH2 =C _{( CH3} ) _CO2 ( _CH2 )3Si _{( OC2H5} ) _{3 , CH2} = _{CHCO2 (} CH ₂ ) _{3SiCH3 ( OC2H5} ) ₂ , _CH2 =C( _CH3 ) _CO2 ( _CH2 ) _{3SiC2H5 (} OCH3) ₂ , _{CH2 =} C _{( CH3} ) _{CO2 (} CH ₂ ) 3Si( _CH3 ) _{2 ( OC2H5} ), _CH2 =C( _CH3 ) _CO2 ( _CH2 ) _3Si ( _CH3 ) _2OH , _{CH2 =} CH( _CH2 ) _3Si ( _OCOCH3 ) ₃ , _CH2 =C( _CH3 ) _CO2 ( _CH2 ) _{3SiC2H5 ( OCOCH3} ) ₂ , _CH2 =C( _CH3 ) _CO2 ( _CH2 ) _{3SiCH3 (} N _{( CH3} ) _COCH3 ) ₂ , _CH2 =CHCO2( _CH2 ) _3SiCH3 [ON _{( CH3} ) _C2H5 ] ₂ , _{CH2 =} C _{( CH3} ) _{CO2 ( CH2} ) _3SiC6H5 (Meth)acrylates such as [ON( _CH3 ) _C2H5 ] ₂ ; _{CH2 =} CHSi[ON=C( _CH3 )(C2H5)] _{3 , CH2 =} CHSi ₍ OCH3 ) ₃ , _CH2 =CHSi( _OC2H5 ) ₃ , _CH2 =CHSiCH3(OCH3) ₂ , _CH2 = _CHSi ( _OCOCH3 ) ₃ , _CH2 = _{CHSi ( CH3} ) _{2 ( OC2H5} ), _CH2 =CHSi( _CH3 ) _2SiCH3 (OCH3) ₂ , _{CH2 = CHSiC2H5 ( OCOCH3} ) ₂ , _{CH2 = CHSiCH3} [ON _{( CH3} ) _C2H5 ] ₂ , Vinylsilanes such as vinyltrichlorosilane or partial hydrolysates thereof, e.g. trimethoxysilylethyl vinyl ether, triethoxysilylethyl vinyl ethers such as vinyl ether, trimethoxysilylbutyl vinyl ether, methyldimethoxysilylethyl vinyl ether, trimethoxysilylpropyl vinyl ether, triethoxysilylpropyl vinyl ether;

These silyl group-containing copolymerizable monomers can be used alone or in combination of two or more.

Silyl group-containing copolymerizable monomers preferably include silicone-based vinyl monomers.

Furthermore, the curable functional group-containing fluoropolymer may contain other monomers as raw material components. Such monomers include, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl cyclohexylcarboxylate, carboxylic acid vinyl esters such as vinyl benzoate and para-t-butyl vinyl benzoate; alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether; ethylene, propylene, n-butene, isobutene; and non-fluorinated olefins such as These can be used alone or in combination of two or more.

The method for producing the curable functional group-containing fluoropolymer is not particularly limited, and known methods can be employed. More specifically, for example, a curable functional group-containing fluoropolymer can be obtained by polymerizing each of the above components using a known polymerization initiator or the like.

The curable functional group-containing fluoropolymer contains a structural unit based on a fluorine-containing polymerizable monomer and a structural unit based on a curable functional group-containing copolymerizable monomer. Preferably, the curable functional group-containing fluoropolymer includes a structural unit based on a fluorine-containing polymerizable monomer, a hydroxyl group-containing copolymerizable monomer, a carboxyl group-containing copolymerizable monomer, an amino group-containing and a structural unit based on at least one monomer selected from the group consisting of a copolymerizable monomer and a silyl group-containing copolymerizable monomer. More preferably, the curable functional group-containing fluoropolymer comprises a structural unit based on a fluorine-containing polymerizable monomer, a hydroxyl group-containing copolymerizable monomer and/or a carboxyl group-containing copolymerizable monomer. based structural units.

In the curable functional group-containing fluoropolymer, the molar ratio of the structural unit based on the fluorine-containing polymerizable monomer is, for example, 80 mol% or more, preferably 90 mol%, relative to the total amount of the curable functional group-containing fluoropolymer. mol % or more, for example, 99 mol % or less, preferably 98 mol % or less. Further, the molar ratio of the structural unit based on the curable functional group-containing copolymerizable monomer is, for example, 1 mol% or more, preferably 2 mol% or more, relative to the total amount of the curable functional group-containing fluoropolymer. and is, for example, 20 mol % or less, preferably 10 mol % or less.

In addition, the content of the curable functional groups contained in the fluoropolymer is preferably the same as the molar ratio of structural units based on the curable functional group-containing copolymerizable monomer. Specifically, the curable functional group is, for example, 1 mol% or more, preferably 2 mol% or more, and preferably 20 mol% or less, relative to the total amount of the curable functional group-containing fluorine-containing polymer. is 10 mol % or less.

The content of curable functional groups can be calculated by appropriately combining NMR, FT-IR, elemental analysis, fluorescent X-ray analysis, and neutralization titration depending on the type of monomer.

Specific examples of such curable functional group-containing fluoropolymers include, for example, curable functional group-containing tetrafluoroethylene (TFE)-based polymers, curable functional group-containing chlorotrifluoroethylene (CTFE)-based polymers, and curable functional group-containing fluoropolymers. Functional group-containing vinylidene fluoride (VdF)-based polymer, curable functional group-containing (meth)acrylic acid fluoroalkyl ester (AFAE)-based polymer, and the like.

Examples of the curable functional group-containing TFE polymer include copolymers of TFE/isobutylene/hydroxybutyl vinyl ether/optionally other monomers, TFE/vinyl versatate/hydroxybutyl vinyl ether/optionally other monomers. copolymers of monomers, copolymers of TFE/VdF/hydroxybutyl vinyl ether/if necessary, other monomers, and the like. These can be used alone or in combination of two or more.

The curable functional group-containing TFE-based polymer is preferably a copolymer of TFE/isobutylene/hydroxybutyl vinyl ether/optionally other monomers, TFE/vinyl versatate/hydroxybutyl vinyl ether/optionally other Copolymers of monomers are mentioned.

Moreover, the curable functional group-containing TFE-based polymer is also available as a commercial product, and examples thereof include Zeffle (registered trademark) GK series (manufactured by Daikin Industries, Ltd.).

The curable functional group-containing CTFE-based polymer includes, for example, a copolymer of CTFE/hydroxybutyl vinyl ether/if necessary, other monomers. These can be used alone or in combination of two or more.

In addition, the curable functional group-containing CTFE-based polymer is also available as a commercial product, for example, Lumiflon (registered trademark) series (manufactured by Asahi Glass), Fluonate (registered trademark) series (manufactured by DIC), Cefralcoat (registered trademark) series (manufactured by Central Glass Co., Ltd.), Zaffron (registered trademark) series (manufactured by Toagosei Co., Ltd.), and the like.

The curable functional group-containing VdF-based polymer includes, for example, a copolymer of VdF/TFE/hydroxybutyl vinyl ether/if necessary, other monomers. These can be used alone or in combination of two or more.

Moreover, the curable functional group-containing VdF-based polymer is also available as a commercial product.

Examples of curable functional group-containing AFAE polymers include fluoro (meth)acrylic acid represented by CF ₃ CF ₂ (CF ₂ CF ₂ ) _n CH ₂ CH ₂ OCOCH=CH ₂ (mixture of n = 3 and 4) Copolymers of alkyl esters/2-hydroxyethyl methacrylate/stearyl acrylate/if necessary, other monomers and the like can be mentioned. These can be used alone or in combination of two or more.

In addition, curable functional group-containing AFAE polymers are also available as commercial products. trademark) series (manufactured by DuPont).

These curable functional group-containing fluoropolymers can be used alone or in combination of two or more.

As the curable functional group-containing fluorine polymer, TFE containing a curable functional group is preferable from the viewpoint of improving pigment (titanium oxide (described later)) dispersibility, weather resistance, copolymerization, chemical resistance, moisture resistance, etc. system polymers.

The content of the curable functional group-containing fluoropolymer in the curable composition is appropriately adjusted so as to fall within the range described below.

Alkoxysilane is preferably a Si atom and preferably 1 to 4, more preferably 1 to 3, and particularly preferably 2 to 3 (hereinafter referred to as x) alkoxy groups bonded to the Si atom. (linear, branched or cyclic alkoxy group) and 4-x alkyl groups (linear, branched or cyclic alkyl group).

Also, the alkoxysilane has a functional group containing at least one element selected from group 15-16 elements (excluding oxygen). Preferably, the alkoxy and/or alkyl groups bonded to the Si atom carry functional groups.

Group 15-16 elements (excluding oxygen) refer to Group 15-16 elements (excluding oxygen) in the periodic table (according to IUPAC Periodic Table of the Elements (version date 8 January 2016). The same shall apply hereinafter.). ). Specifically, for example, nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), Group 15 elements such as bismuth (Bi), sulfur (S), selenium (Se), Group 16 elements excluding oxygen, such as tellurium (Te) and polonium (Po), can be mentioned. Nitrogen (N) and sulfur (S) are preferred. A preferred example of a group 15 element is nitrogen (N) and a preferred example of a group 16 element is sulfur (S).

The Group 15-16 elements (excluding oxygen) can be used alone or in combination of two or more.

In other words, the functional group of the alkoxysilane should contain at least one element of Groups 15 and 16 (excluding oxygen), and may contain two or more.

Moreover, the phrase "excluding oxygen" does not deny that oxygen is contained in the functional group. That is, if the functional group contains at least one element of Groups 15 and 16 (excluding oxygen), it may contain oxygen as another element. Preferably, the functional group does not contain oxygen.

More specifically, such functional groups are not particularly limited, but primary amino groups (—NH ₂ ), secondary amino groups (—NH—), mercapto groups (—SH), isocyanate groups (—NCO ) and the like. These functional groups can be used alone or in combination of two or more. The functional group preferably includes a primary amino group (--NH ₂ ), a secondary amino group (--NH--) and a mercapto group (--SH).

Specific examples of alkoxysilanes having such functional groups include alkoxysilanes having a primary amino group, alkoxysilanes having a secondary amino group, and alkoxysilanes having both a primary amino group and a secondary amino group. , alkoxysilanes having a mercapto group, and the like.

If the curable composition contains these alkoxysilanes, it is possible to suppress the occurrence of white turbidity that is considered to be caused by phase separation. This is because the carbonyl group, ester group, or the like of the blocking agent (blocking agent having an O=C—CH—C=O skeleton) reacts with the functional group (amino group, mercapto group, etc.) of the alkoxysilane. It is presumed that the phase separation is suppressed by or by their strong interaction.

More specifically, the alkoxysilane having a primary amino group is an alkoxysilane having a primary amino group and no secondary amino group, such as 3-aminopropylmethyldimethoxysilane, 3-amino propyltrimethoxysilane and the like.

The alkoxysilane having a secondary amino group is an alkoxysilane having a secondary amino group and not having a primary amino group, such as N-phenyl-3-aminopropyltrimethoxysilane.

The alkoxysilane having both a primary amino group and a secondary amino group is an alkoxysilane having both a primary amino group and a secondary amino group, such as N-β(aminoethyl)γ-aminopropyltrimethoxysilane (alias: N-2-(aminoethyl)-3-aminopropyltrimethoxysilane), N-β (aminoethyl) γ-aminopropyltriethoxysilane (alias: N-2-(aminoethyl)-3-amino propyltriethoxysilane), N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane (alias: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane), N-β (aminoethyl) γ- Aminopropylmethyldiethoxysilane (alias: N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane) and the like can be mentioned.

Alkoxysilanes having a mercapto group include, for example, 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane.

These alkoxysilanes can be used alone or in combination of two or more.

As the alkoxysilane, from the viewpoint of adhesion, preferably an alkoxysilane having a primary amino group, an alkoxysilane having both a primary amino group and a secondary amino group, and from the viewpoint of low yellowness, more preferably , alkoxysilanes having a primary amino group.

In addition, if the curable composition contains an alkoxysilane having a primary amino group, an alkoxysilane having both a primary amino group and a secondary amino group, or the like, those amino groups and the isocyanate group of the blocked isocyanate (the isocyanate group regenerated by elimination of the blocking agent) may react to form a urea bond. Further, in heating (baking), which will be described later, a silyl cross-linking reaction with water may occur to form a structural unit of Si--O--Si.

The content of the alkoxysilane in the curable composition is appropriately adjusted so as to fall within the range described below.

Moreover, the curable composition can further contain titanium oxide as an optional component. Preferably, the curable composition contains titanium oxide.

Titanium oxide is a white pigment such as titanium monoxide (TiO), dititanium trioxide (Ti ₂ O ₃ ), titanium dioxide (TiO ₂ ), titanium peroxide (TiO _{3.nH 2} O), and the like. mentioned. Titanium dioxide is preferred.

Titanium dioxide includes, for example, crystalline titanium dioxide such as anatase type, rutile type, and brookite type. Rutile-type titanium dioxide is preferred. Titanium dioxide may be produced by any production method such as a sulfuric acid method, a chlorine method, or a vapor phase method, and may be treated with a known treatment agent containing, for example, Al, Si, Zn, or the like. may be Furthermore, it is preferred to use a weather resistant grade.

These titanium oxides can be used alone or in combination of two or more.

The content of titanium oxide in the curable composition is appropriately adjusted so as to fall within the range described below.

The curable composition can be prepared as a one-component coating agent by mixing the above-mentioned blocked isocyanate, curable functional group-containing fluoropolymer and alkoxysilane (and titanium oxide if necessary).

The mixing method is not particularly limited, and for example, batch mixing or sequential mixing may be used. For example, the curable functional group-containing fluoropolymer and titanium oxide can be premixed, and then the resulting mixture, blocked isocyanate, and alkoxysilane can be mixed.

The content of each component (based on solid content) in the curable composition is as follows.

That is, the content of the blocked isocyanate (based on solid content) is, for example, 1% by mass or more, preferably 5% by mass or more, for example, 50% by mass or less, relative to the total solid content of the curable composition. Preferably, it is 30% by mass or less.

Further, the content of the curable functional group-containing fluoropolymer (based on solid content) is, for example, 20% by mass or more, preferably 30% by mass or more, relative to the total solid content of the curable composition. 95% by mass or less, preferably 90% by mass or less.

In addition, the content of alkoxysilane (based on solid content) is, for example, 0.1% by mass or more, preferably 0.3% by mass or more, relative to the total solid content of the curable composition. % by mass or less, preferably 5% by mass or less.

In addition, the content of titanium oxide (based on solid content) is, for example, 0% by mass or more, preferably 10% by mass or more, for example, 70% by mass or less, relative to the total solid content of the curable composition. Preferably, it is 50% by mass or less.

In addition, the blocked isocyanate is, for example, 2 parts by mass or more, preferably 5 parts by mass or more, and for example, 40 parts by mass or less, preferably with respect to 100 parts by mass as the total amount of the blocked isocyanate and the curable functional group-containing fluorine polymer. is 20 parts by mass or less. Further, the curable functional group-containing fluoropolymer is, for example, 60 parts by mass or more, preferably 80 parts by mass or more, and is, for example, 98 parts by mass or less, preferably 95 parts by mass or less.

Also, the molar ratio of the curable functional group of the curable functional group-containing fluoropolymer to the isocyanate group of the isocyanate compound in the blocked isocyanate (that is, the latent isocyanate group blocked by the blocking agent) (curable functional group/isocyanate group) is 0.5 or more, preferably 0.9 or more, and 10 or less, preferably 5 or less.

Furthermore, in the curable composition, the content of the alkoxysilane is 0.2 parts by mass or more, preferably 0.3 parts by mass or more, relative to 100 parts by mass of the total amount of the blocked isocyanate and the curable functional group-containing fluoropolymer. , more preferably 0.35 parts by mass or more, more preferably 0.4 parts by mass or more, and 8 parts by mass or less, preferably 7 parts by mass or less, more preferably 6 parts by mass or less.

In the curable composition, the content of titanium oxide, which is optionally used, is 0 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the curable functional group-containing fluoropolymer. Preferably, it is 100 parts by mass or less. On the other hand, when titanium oxide is used, it is preferably used in a proportion of 20 parts by mass or more.

In addition, if necessary, the curable composition may further contain antioxidants, other curing accelerators, ultraviolet absorbers, light stabilizers, fillers, silane coupling agents, epoxy resins, catalysts, coating improvers. agents, leveling agents, nucleating agents, lubricants, release agents, antifoaming agents, thickeners, plasticizers, surfactants, pigments (excluding titanium oxide), pigment dispersants, dyes, organic or inorganic fine particles, Additives such as fungicides, flame retardants, adhesion improvers and matting agents may be included.

Examples of antioxidants include pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4- hydroxyphenyl)propionate, 3,9-bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl]-2,4, Phenolic antioxidants such as 8,10-tetraoxa-spiro[5,5]undecane, phosphites such as triphenylphosphite, tris(2-ethylhexyl)phosphite, tris(tridecyl)phosphite Antioxidants, for example, phosphoric acid ester antioxidants such as dibutyl phosphate and 2-ethylhexyl acid phosphate. These antioxidants can be used alone or in combination of two or more.

The antioxidant is preferably a phosphate ester-based antioxidant.

The blending ratio of the antioxidant is not particularly limited, and is appropriately set according to the purpose and application.

The timing of addition of these additives is not particularly limited, and may be added in advance to each component described above (blocked isocyanate, curable functional group-containing fluorine polymer, alkoxysilane, etc.), and each component described above may be added in advance. may be added at the same time when mixing the components, or may be added separately after mixing the components described above.

Then, such a curable composition is cured by a method described later to obtain a cured product, thereby obtaining the protective resin layer 3 .

That is, the protective resin layer 3 is formed from the cured product of the curable composition.

Therefore, such a protective resin layer 3 is excellent in solvent resistance.

Further, in the solar cell module 6 (described later) obtained using the laminate 1 including the protective resin layer 3, the adhesion between the protective resin layer 3 and the encapsulant layer 2 and the adhesion between the protective resin layer 3 and the substrate 4 (described later), in particular, excellent adhesiveness between the protective resin layer 3 and the encapsulant layer 2, and furthermore, excellent adhesiveness between the encapsulant layer 2 and the base material 4 (described later). Excellent for

Moreover, a solar cell module 6 (described later) obtained by using the laminate 1 having this protective resin layer 3 is excellent in moisture resistance and heat resistance.

Then, the laminate 1 is manufactured together with the solar cell module 6 in manufacturing the solar cell module 6 .

A method for manufacturing the laminate 1 and the solar cell module 6 will be described in detail below.

To manufacture the laminate 1 and the solar cell module 6, first, the surface layer 5 is prepared as shown in FIG. 2(A).

The surface layer 5 is a member for protecting the surface of the solar cell module 6, and includes, for example, a glass substrate.

The thickness of the surface layer 5 is, for example, 0.5 mm or more and, for example, 10 mm or less.

Next, the sealing material layer 2 sealing the solar cells 7 is laminated on the surface of the surface layer 5 .

In order to laminate the sealing material layer 2 sealing the solar cells 7 on the surface of the surface layer 5, first, a sealing material composition is prepared.

To prepare the encapsulant composition, the olefin-based encapsulant described above is mixed with additives added as necessary.

Additives include, for example, silane coupling agents, organic peroxides, and auxiliary agents.

These additives can be used alone or in combination of two or more.

The blending ratio of the additive is appropriately set according to the purpose and application.

The mixing method is not particularly limited, and known kneading machines such as rolls, Banbury mixers and kneader lab plastomills can be used. Moreover, the mixing conditions are not particularly limited, and are appropriately set according to the equipment used.

A sealing material composition is thus prepared.

Next, the encapsulant composition is molded to prepare the encapsulant layer 2 .

Specifically, the encapsulating material layer 2 is composed of a first encapsulating material layer 8 having half the thickness of the encapsulating material layer 2 and a second encapsulating material layer 9 having half the thickness of the encapsulating material layer 2. Prepared separately.

Examples of molding methods include injection molding, extrusion molding, inflation molding, pultrusion molding, and compression molding.

Then, in order to laminate the sealing material layer 2 sealing the solar cells 7 on the surface of the surface layer 5, the first sealing material layer 8 is placed on the surface of the surface layer 5 as shown in FIG. Next, as shown in FIG. 2(C), the solar cell 7 is arranged on the surface of the first sealing material layer 8, and then, as shown in FIG. 2(D), the solar cell 7 The second sealing material layer 9 is laminated on the surface of the first sealing material layer 8 so as to seal the .

As a result, the encapsulant layer 2 in which the solar cells 7 are sealed (embedded) in the central portion in the thickness direction is formed.

The thickness of the sealing material layer 2 is, for example, 0.1 mm or more and, for example, 10 mm or less.

Separately, as shown in FIG. 2(E), a protective resin layer 3 is laminated on the surface of the substrate 4 .

In order to laminate the protective resin layer 3 on the surface of the base material 4, a curable composition is applied to the surface of the base material 4, followed by drying and curing reaction.

The base material 4 is a member for protecting the solar cell module 6 from heat, ultraviolet rays, moisture, and the like, and includes, for example, a PET film, a fluorine film, and the like.

The thickness of the base material 4 is, for example, 0.2 mm or more and, for example, 10 mm or less.

The method of applying the curable composition is not particularly limited, and examples include spray coaters, curtain spray coaters, gravure coaters, doctor coaters, bar coaters, call coaters, reverse roll coaters, curtain coaters, beads, spirals, slots, and the like. A known coating method can be used.

The temperature conditions in the drying and curing reaction are, for example, 40° C. or higher, preferably 80° C. or higher, and for example, 300° C. or lower, preferably 200° C. or lower. Also, the required time is, for example, 30 seconds or more and, for example, 3 days or less.

As a result, the blocking agent blocking the blocked isocyanate reacts with the curable functional group in the curable functional group-containing fluoropolymer, or the isocyanate group regenerated by elimination of the blocking agent from the blocked isocyanate and curing The curable functional group in the functional group-containing fluoropolymer reacts and cures to form a coating film. As a result, the protective resin layer 3 is obtained.

Moreover, if necessary, the protective resin layer 3 can be cured at 20° C. or higher and 300° C. or lower for 1 minute or longer and 30 days or shorter.

The thickness of the protective resin layer 3 is, for example, 1 μm or more and, for example, 50 μm or less.

Next, as shown in FIG. 2(F), a protective resin is applied so that the sealing material layer 2 laminated on the surface of the surface layer 5 and the protective resin layer 3 laminated on the surface of the substrate 4 are in contact with each other. The layer 3 is laminated on the surface of the sealing material layer 2 and is thermocompression bonded (hot press) as shown in FIG. 2(G).

In thermocompression bonding, specifically, the substrate 4 and the surface layer 5 are pressed from both sides in the thickness direction at, for example, 0.1 MPa or more and 50 MPa or less, and heated to 30° C. or more and 180° C. or less. The thermocompression bonding time is, for example, 1 minute or more and 60 minutes or less.

As a result, the surface layer 5 and the sealing material layer 2 are heat-sealed, and the sealing material layer 2 and the protective resin layer 3 are heat-sealed.

As a result, the laminate 1 including the sealing material layer 2 and the protective resin layer 3 in this order is obtained, and the laminate 1, the solar cells 7 sealed in the laminate 1, and one side of the laminate 1 A solar cell module 6 having a substrate 4 arranged on the other side of the laminate 1 and a surface layer 5 arranged on the other side of the laminate 1 is obtained.

In other words, the solar cell module 6 includes the surface layer 5, the laminate 1, and the substrate 4 in this order. Specifically, the solar cell module 6 includes a surface layer 5 , a sealing material layer 2 sealing the solar cells 7 , a protective resin layer 3 , and a substrate 4 in this order.

The thickness of the solar cell module 6 is, for example, 1 mm or more and, for example, 30 mm or less.

In solar cell module 6 , protective resin layer 3 in laminate 1 is interposed between encapsulant layer 2 and base material 4 to protect encapsulant layer 2 .

The laminate 1 comprises a sealing material layer 2 containing an olefin-based sealing material, and a protective resin which is a cured product of a curable composition containing a blocked isocyanate, a curable functional group-containing fluoropolymer, and an alkoxysilane. A layer 3 is provided.

Therefore, the adhesiveness between the protective resin layer 3 and the sealing material layer 2 and the adhesiveness between the protective resin layer 3 and the base material 4 (described later) are excellent. The adhesiveness between the sealing material layer 2 and the base material 4 is excellent.

Specifically, the maximum delamination strength between the protective resin layer 3 and the sealing material layer 2 is, for example, 50 N/10 mm or more, preferably 60 N/10 mm or more, and usually 120 N/10 mm or less. .

If the maximum delamination strength is equal to or higher than the lower limit, the adhesion between the sealing material layer 2 and the protective resin layer 3 is excellent, and the adhesion between the sealing material layer 2 and the base material 4 is improved. Excellent.

The method for measuring the maximum delamination strength will be described in detail in the examples below.

Furthermore, the solar cell module 6 having such a laminate 1 is excellent in moisture resistance and heat resistance.

Specifically, even if such a solar cell module 6 is exposed outdoors for a long period of time, peeling of the encapsulant layer 2 and the substrate 4 can be suppressed.

Such moisture resistance and heat resistance can be confirmed by a heat and moisture resistance test (pressure cooker test (PCT)).

Specifically, the retention rate of the maximum delamination strength between the sealing material layer 2 and the protective resin layer 3 after the pressure cooker test is, for example, 10% or more, preferably 15% or more. 95% or less.

If the above retention rate is equal to or higher than the above lower limit, the solar cell module 6 including such a laminate 1 will be excellent in moisture resistance and heat resistance.

In addition, the method for measuring the retention rate will be described in detail in Examples described later.

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. "Parts" and "%" are based on mass unless otherwise specified. In addition, specific numerical values such as the mixing ratio (content ratio), physical property values, and parameters used in the following description are the corresponding mixing ratios ( Content ratio), physical properties, parameters, etc. be able to.
1. Production of Laminate and Solar Cell Module Type Laminate (Production Example 1) (Preparation of Blocked Isocyanate)
Using Takenate D-127N (a solution of an isocyanurate derivative of 1,3-bisisocyanatomethylcyclohexane, manufactured by Mitsui Chemicals), methyl isobutyl ketone of an isocyanurate derivative of 1,3-bisisocyanatomethylcyclohexane was obtained by solvent replacement. (MIBK) solution (solid content 75% by mass) was prepared (hereinafter sometimes referred to as D-127N (MIBK)). 459.13 g of D-127N (MIBK), 278.23 g of MIBK, and 254.39 g of diethyl malonate were added to a four-necked flask sealed with nitrogen, and mixed well at room temperature for 15 minutes. At this time, the equivalent ratio (active group/isocyanate group) of the active group (blocking group) in the blocking agent to the isocyanate group was set to 1.05. Then, 2.92 g of a 28% sodium methylate/methanol solution (blocking catalyst) was added and reacted at 60° C. until the amount of residual isocyanate was 1% or less. After completion of the reaction, the temperature was returned to room temperature, 4.89 g of 2-ethylhexyl acid phosphate (antioxidant) was added, and the mixture was mixed at room temperature for 1 hour to obtain a blocked isocyanate (latent NCO % 6.0).

(Production example 2)
500 parts by mass of pentamethylene diisocyanate, 1 part by mass of isobutyl alcohol, 2,6-di(tert-butyl)-4- 0.3 parts by mass of methylphenol and 0.3 parts by mass of tris(tridecyl)phosphite were charged and reacted at 80° C. for 2 hours.

Then, 0.05 part by mass of N-(2-hydroxypropyl)-N,N,N-trimethylammonium-2-ethylhexanoate was added as a trimerization catalyst. The refractive index and isocyanate purity were measured, and the reaction was continued until a predetermined reaction rate was reached. After 50 minutes, the predetermined reaction rate was reached, so 0.12 parts by mass of o-toluenesulfonamide was added (isocyanate group conversion rate: 10 mass %). The resulting reaction solution was passed through a thin film distillation apparatus (degree of vacuum 0.093 KPa, temperature 150° C.) to remove unreacted pentamethylene diisocyanate. 0.02 parts by mass of toluenesulfonamide was added to obtain a polyisocyanate composition (isocyanate group concentration: 24% by mass).

(Production Example 3) (Mixing of curable functional group-containing fluoropolymer and titanium oxide)
In a mayonnaise bottle, 37.05 g of Zeffle GK-570 (curable functional group-containing fluoropolymer, curable functional group: hydroxyl group, manufactured by Daikin Industries, hydroxyl value 55-65 mgKOH/g), titanium oxide CR93 (manufactured by Ishihara Sangyo Co., Ltd.) 48. 60 g, 31.34 g of butyl acetate (solvent), and 115 g of glass beads were added, mixed lightly, and then well mixed on a paint shaker for 2 hours. Next, 54.89 g of Zeffle GK-570 (curable functional group-containing fluoropolymer) and 8.11 g of butyl acetate (solvent) were added to the resulting mixture and mixed well. After that, the glass beads were removed by filtration to obtain a mixture of a curable functional group-containing fluoropolymer and titanium oxide (white paint varnish). In the mixture, the proportion of titanium oxide was 52.6 parts by mass with respect to 100 parts by mass of Zeffle GK-570 (curable functional group-containing fluoropolymer).

Example 1
The molar ratio ( They were well mixed at a ratio of 2 (hardening functional group/isocyanate group). After that, KBM-903 (aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) is added so as to be 1 part by mass with respect to 100 parts by mass of the total amount of blocked isocyanate and curable functional group-containing fluoropolymer, mixed well, and cured. A liquid composition (one-liquid type coating agent) was obtained. After that, as shown in FIG. 3(A), the resulting solution was coated 175 on a plasma-treated PET film 10 (Lumirror X10S, manufactured by Toray) so that the film thickness after drying was 10 to 15 μm. C. for 2 minutes. Thereby, the curable composition was cured, and the protective resin layer 3 was laminated on the upper surface of the PET film 10 .

Separately, isotactic polypropylene (iPP) (propylene-ethylene-1-butene copolymer having an isotactic structure) 20 parts by weight, and propylene-ethylene-1-butene copolymer (PEBR) (propylene-ethylene -1-butene copolymer), silane coupling agent (VTMOS) (vinyltrimethoxysilane) 2.0 parts, organic peroxide (PH25B) 0.09 parts, auxiliary agent (TAIC) 0.2 parts were blended and kneaded (190° C., 5 min) in a Laboplastomill to obtain a sealing material composition. Then, a press molding machine was used to form a sealing material layer 2 (thickness: 0.6 mm) from the sealing material composition.

Then, two sealing material layers 2 were laminated, and as shown in FIG. 3B, a glass plate 11 (thickness: 2 mm) was laminated on the upper surface thereof.

Next, as shown in FIG. 3(C), the protective resin layer is formed so that the sealing material layer 2 laminated on the surface of the glass plate 11 and the protective resin layer 3 laminated on the surface of the PET film are in contact with each other. 3 is laminated on the surface of the sealing material layer 2, and then, as shown in FIG. crimped.

Thus, the laminate 1 was manufactured, and the solar cell module type laminate 12 was manufactured.

Note that the solar cell module type laminate 12 is a test piece of a solar cell module that does not include solar cells in the sealing material layer 2 .

Comparative example 1
The blocked isocyanate of Production Example 1 was changed to the isocyanate composition of Production Example 2, and the molar ratio of the curable functional group (hydroxyl group) of the curable functional group-containing fluorine polyol to the isocyanate group (curable functional group/isocyanate group) A laminated body 1 and a solar cell module type laminated body 12 were manufactured in the same manner as in Example 1, except that the ratio was set to 1.

In Comparative Example 1, the isocyanate composition, the curable functional group-containing fluoropolyol, and aminopropyltrimethoxysilane are a two-component coating agent.

Comparative example 2
A mixture was obtained by blending 2.0 parts of a silane coupling agent (VTMOS) (vinyltrimethoxysilane) with 100 parts by weight of an ethylene-vinyl acetate copolymer (EVA). Then, using a press molding machine, the mixture was molded into a sealing material layer 2 (thickness: 0.6 mm) made of EVA.

A laminate 1 and a solar cell module laminate 12 were produced in the same manner as in Example 1, except that the encapsulant layer 2 of Example 1 was changed to the encapsulant layer 2 made of EVA. .

Comparative example 3
A laminate 1 and a solar cell module laminate 12 were produced in the same manner as in Comparative Example 1, except that the encapsulant layer 2 of Comparative Example 1 was changed to the encapsulant layer 2 made of EVA. .
2. Evaluation (solvent resistance)
Disposable chopsticks were wrapped with absorbent cotton and thoroughly soaked in methyl ethyl ketone (MEK). This was pressed against the protective resin layer with a load of 1 kg, rubbed 100 times, and then the appearance was observed.

The solvent resistance was evaluated according to the following criteria. The results are shown in Table 1. ◎: No change in appearance was observed.
O: Traces of rubbing were observed.
Δ: Peeling was observed in part of the protective resin layer.
x: Dissolution of the protective resin layer or separation of the protective resin layer was observed.

(Adhesion (delamination test))
The delamination strength between the sealing material layer 2 and the protective resin layer 3 was measured using a tensile compression tester (Model 205N, manufactured by Intesco).

A strip of 10 mm width was cut from the solar cell module laminate, and a delamination test (180 degree delamination, test speed of 50 mm/min) was performed using a tension/compression tester.

The maximum value (maximum delamination strength) on the chart was read from the measurement result of the delamination strength. The results are shown in Table 1.

(Moisture resistance and heat resistance (heat and humidity resistance test (pressure cooker test (PCT))
Using a pressure cooker tester, measure the delamination strength of the encapsulant layer 2 and the protective resin layer 3 after 48 hours under conditions of a temperature of 121 ° C. and a humidity of 100%, and the retention rate is calculated according to the following formula (1). asked. The results are shown in Table 1.

(Interlayer peel strength after 48 hours under conditions of temperature 121 ° C. and humidity 100% / interlayer peel strength before heat and humidity resistance test) (1)

Details of the abbreviations in the table are given below.
D-127N: D-127N (MIBK) obtained in Production Example 1, a methyl isobutyl ketone (MIBK) solution of the isocyanurate derivative of 1,3-bisisocyanatomethylcyclohexane (H ₆ XDI) (solid content: 75% by mass) )
KBM-903: aminopropyltrimethoxysilane, Shin-Etsu Chemical isotactic polypropylene (iPP): ethylene content 3.0 mol%, 1-butene content 1.0 mol%, MFR (230 ° C.) 7 g / 10 min, melting point 140 ℃
Propylene/ethylene/1-butene copolymer (PEBR): ethylene content 14.0 mol%, 1-butene content 20 mol%, MFR (230°C) 8.5 g/10 min, melting point not observed (ΔH: 0 .5 J/g), molecular weight distribution (Mw/Mn) 2.0, Shore A hardness 37
Ethylene-vinyl acetate copolymer (EVA): density 950 kg/m ³ , vinyl acetate content 28% by mass, MFR (190°C) 15 g/10 min, melting point 71°C
Silane coupling agent (VTMOS): vinyltrimethoxysilane, Dow Corning Toray organic peroxide (PH25B): dialkyl peroxide, Perhexa 25B, NOF auxiliary agent (TAIC): triallyl isocyanurate ( TAIC), trade name M-60 (TAIC content 60%), manufactured by Nippon Kasei Co., Ltd.

1 Laminate 2 Encapsulant Layer 3 Protective Resin Layer 4 Base Material 5 Surface Layer 6 Solar Cell Module 7 Solar Cell

Claims (4)

A sealing material layer and a protective resin layer are provided in order,
The protective resin layer is a cured product of a curable composition containing a blocked isocyanate, a curable functional group-containing fluoropolymer, and an alkoxysilane,
The blocked isocyanate includes a blocked isocyanate in which the isocyanate group of the isocyanate compound is blocked by a blocking agent having an O=C-CH-C=O skeleton,
A laminate, wherein the sealing material layer contains an olefin-based sealing material. 2. The laminate according to claim 1, wherein the maximum delamination strength between said sealing material layer and said protective resin layer is 50 N/10 mm or more. 3. The laminate according to claim 1, wherein a retention rate of maximum delamination strength between said sealing material layer and said protective resin layer after a pressure cooker test is 15% or more. A laminate according to claims 1 to 3,
a solar cell sealed in the laminate;
a base material arranged on one side of the laminate;
and a surface layer arranged on the other side of the laminate.

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