WO2011161824A1 - Composition for solar cell panel sealing material and solar cell panel using the same - Google Patents

Abstract

The disclosed composition for a solar cell panel sealing material contains (a) a vinyl ester resin or an unsaturated polyester resin (10-40 mass%), (b) vinyl monomers and/or (meth)acrylate monomers (30-70 mass%), (c) a denaturant (5-40 mass%) (wherein the sum of the mass percentages of the aforementioned components (a) to (c) is 100 mass%), and (d) a UV-curing agent (0.1-15 parts mass per 100 parts mass of the aforementioned components (a) to (c) combined).

Description

Composition for solar cell panel encapsulant and solar cell panel using the same

The present invention relates to a solar cell panel encapsulant composition and a solar cell panel using the same, and in particular, a translucent member disposed on the light receiving surface side of the solar cell and a back member disposed on the back surface side. Composition for solar cell panel encapsulant that is excellent in adhesion, transparency, flexibility, adhesion, tensile strength, weather resistance, especially water resistance and manufacturing cost is suppressed, and solar cell using the same Regarding panels.

In recent years, in order to mitigate the global environmental destruction caused by the global warming caused by the energy crisis caused by the shortage of energy supply capacity accompanying the rapid increase in energy demand or the greenhouse effect due to the increase of carbon dioxide, A source is desired.
In particular, a solar cell that is clean, highly safe, and has the ability to supply energy permanently for a long period of time is a new energy source with the greatest expectations for the above demand.

Generally, a solar battery is a solar battery module that electrically connects a single solar battery cell or a plurality of solar battery cells to form one power generation unit, and a plurality of the solar battery modules are connected on a support plate. Used as a solar panel. The solar battery panel further seals the solar battery cell between the translucent member having translucency disposed on the light receiving surface side of the solar battery cell, the back member disposed on the back surface side, and both members. And a sealing material.

A solar cell is an energy generating element utilizing the photovoltaic effect of a semiconductor. In general, several solar cells shown below are well known.
1. Crystalline solar cell A p-type or n-type single crystal or polycrystal wafer doped with n-type or p-type impurities to form a pn junction.
2. Amorphous silicon solar battery cell A mono-Si or Silang gas is decomposed by heat, high-frequency electric field or light, and a-Si is generated and deposited.
3. Compound semiconductor solar cell A pn structure formed by liquid phase epitaxial growth of p-type GaAs on n-type GaAs, or a pn structure formed by stacking and firing n-type CdS and p-type CdTe.
Other examples include CuInSe ₂ solar cells, n-type CdS / p-type CuInS ₂ solar cells, and the like.

Such a solar cell panel is required to operate stably for 20 to 30 years in an outdoor environment irradiated with sunlight. For special products, it is necessary to operate stably in high vacuum space.

However, the solar cell panel has the following problems.
Under solar light irradiation, the solar cell panel is usually heated to about 80 ° C to 100 ° C. At this temperature, the sealing material becomes extremely plasticized, leading to a sharp drop in adhesive strength, and peeling and deformation. As a result, rainwater, humidity, and the like enter, and the operation as a solar cell is significantly impaired. In addition, at night time, since there is no irradiation of sunlight, it is cooled rapidly. For example, a solar cell panel at night may be up to several tens of degrees below zero in an extreme case.
Thus, during the day and at night, the temperature may change from a high temperature region of + 80 ° C. to 100 ° C. to a low temperature region of several tens of degrees below zero, and the solar cell is subjected to severe temperature conditions that repeat high and low temperatures. As a result, the constituent material is expanded and contracted, so that the peeling is further promoted and the operation of the solar cell is reduced due to rain water, humidity, and the like.

From such a point, the solar cell panel sealing material has been desired to have improved temperature characteristics and enhanced adhesion.
For example, in Patent Document 1 (US Pat. No. 3,957,537), a heating adhesive represented by a ternary copolymer of polyvinyl butyral resin, ethylene-methyl methacrylate-methacrylic acid, etc. is used, and a glass plate is used on the surface. And sealed. In Patent Document 2 (US Pat. No. 4,499,658), a silicone-based primer and a crosslinking agent such as peroxide are added to ethylene / vinyl acetate binary copolymer or polyvinyl butyral resin as a sealing material. Used.
However, even with these proposals, it cannot be said that the characteristics as a solar cell encapsulant are sufficiently achieved.

At present, ethylene-vinyl acetate copolymer resin (EVA) is used as a solar cell panel sealing material. EVA is excellent in physical properties such as transparency, flexibility, tensile strength, weather resistance, etc., but a translucent member (eg, glass or polycarbonate) having translucency disposed on the light receiving surface side of the solar battery cell. , Adhesiveness with the back surface member (for example, polyester resin) disposed on the back surface side of the solar battery cell is insufficient, peeling from both members is likely to occur, and the water resistance is inferior due to rainwater, humidity, etc. There is a problem that the operation of the solar cell panel tends to be lowered.
Further, in the manufacturing process of the solar cell panel, in order to make EVA function as a sealing material, several tens of minutes of thermocompression bonding is necessary, and the thickness of the sealing material layer needs to be as thick as 100 to 200 μm. In addition, there is a problem that the manufacturing cost increases.

US Pat. No. 3,957,537 U.S. Pat. No. 4,499,658

Therefore, the object of the present invention is excellent in adhesiveness between the translucent member arranged on the light receiving surface side of the solar battery cell and the back member arranged on the back surface side, transparency, flexibility, adhesiveness, tensile strength, It is providing the composition for solar cell panel sealing materials which is excellent in weather resistance, especially water resistance, and the manufacturing cost is suppressed, and a solar cell panel using the same.

As a result of intensive studies, the present inventor has found that a composition containing the following components (a), (b), (c) and (d) in a specific quantitative relationship can solve the above problems. The headline and the present invention were completed.

That is, the present invention is as follows.
1. (A) Vinyl ester resin or unsaturated polyester resin 10 to 40% by mass
(B) Vinyl monomer and / or (meth) acrylate monomer 30 to 70% by mass
(C) modifying agent 5-40% by mass,
(However, the total of the components (a) to (c) is 100% by mass)
And (d) an ultraviolet curing agent A composition for a solar cell panel encapsulant containing 0.1 to 15 parts by mass with respect to a total of 100 parts by mass of the components (a) to (c).
2. The said component (a) is epoxy (meth) acrylate, The composition for solar cell panel sealing materials of said 1 characterized by the above-mentioned.
3. 3. The solar cell panel encapsulant composition as described in 1 or 2 above, wherein the component (b) is a monomer having an N-vinyl group.
4). The component (c) is a polyol (c-1) having a hydroxyl value of 40 to 330 mgKOH / g; and a polyol (c-2) having a hydroxyl value of 40 to 330 mgKOH / g and an acid value of 2 to 20 mgKOH / g Modified rubber (c-3); at least one selected from the group consisting of compound (c-4) having an epoxy equivalent of 150 to 700 g / mol; The composition for solar cell panel sealing materials of description.
5. The component (c-1) is a castor oil-based polyol (c-1-1) having a hydroxyl value of 40 to 330 mgKOH / g; a polybutadiene-based polyol (c-1-2) having a hydroxyl value of 40 to 330 mgKOH / g; 5. The solar cell panel sealing according to 4 above, which is at least one selected from the group consisting of a polyisoprene-based polyol having a value of 40 to 330 mg KOH / g or a hydrogenated product (c-1-3) thereof Material composition.
6). 6. The solar cell panel sealing according to 5 above, wherein the component (c-1) is an aromatic castor oil-based polyol (c-1-1-1) having a hydroxyl value of 40 to 330 mgKOH / g Material composition.
7). The component (c-2) is a castor oil-based polyol (c-2-1) having a hydroxyl value of 40 to 330 mgKOH / g and an acid value of 2 to 20 mgKOH / g. The composition for solar cell panel sealing materials as described in any one of.
8). 5. The solar cell panel encapsulant composition as described in 4 above, wherein the component (c-3) is acid-modified polybutadiene or acid-modified polyisoprene.
9. 5. The composition for solar cell panel sealing material according to 4 above, wherein the component (c-4) is a polyepoxy compound (c-4-1) having an epoxy equivalent of 150 to 250 g / mol.
10. 5. The solar cell panel sealing material according to 4 above, wherein the component (c-4) is a polymer (c-4-2) having a saturated skeleton having an epoxy equivalent of 500 to 700 g / mol. Composition.
11. Single or multiple solar cells;
A translucent member having translucency disposed on the light-receiving surface side of the solar battery cell;
A back member disposed on the back side of the solar cell;
In a solar battery panel comprising: a sealing material that seals the solar battery cell between the translucent member and the back member;
11. A solar cell panel, wherein the encapsulant comprises the solar cell panel encapsulant composition as described in any one of 1 to 10 above.
12 12. The solar cell panel as described in 11 above, wherein the translucent member is glass or polycarbonate resin, and the back member is polyester resin.

Since the composition for a solar cell panel encapsulant of the present invention contains the components (a), (b), (c) and (d) with a specific quantitative relationship, the solar cell receives light. It is excellent in adhesiveness between a translucent member disposed on the surface side, particularly glass or polycarbonate, and a back surface member disposed on the back side, particularly a polyester resin such as polyethylene terephthalate. Therefore, peeling from both members hardly occurs, and intrusion of rainwater, humidity, and the like from the end of the panel is suppressed, and the water resistance is excellent. Thereby, the operation | movement fall of a solar cell panel can be prevented. Moreover, since it is excellent in this adhesiveness, while the thickness of a sealing material can be made thin, the thermocompression bonding like the conventional EVA is not required. Therefore, the manufacturing cost can be suppressed.
Moreover, the composition for solar cell panel sealing materials of this invention is excellent also in transparency, a softness | flexibility, tensile strength, and a weather resistance. Furthermore, the composition for a solar cell panel encapsulant of the present invention can provide stable storage stability that does not separate with time, hardly generate bubbles, and can provide smooth surface properties.
Since the solar cell panel of the present invention uses the composition for a solar cell panel encapsulant as an encapsulant, the translucent member, particularly glass or polycarbonate, and the back member, particularly polyethylene terephthalate. Such a polyester resin is excellent in adhesiveness, and the sealing material is hardly peeled off from both members even under severe use environment, and intrusion of rainwater, humidity and the like is suppressed and water resistance is excellent. Thereby, the operation | movement fall of a solar cell panel can be prevented. Moreover, since it is excellent in this adhesiveness, while the thickness of a sealing material can be made thin, the thermocompression bonding like the conventional EVA is not required. Therefore, the manufacturing cost can be suppressed. Moreover, the solar cell panel of this invention is excellent also in transparency, a softness | flexibility, tensile strength, and a weather resistance.

Hereinafter, the present invention will be described in more detail.
(A) Vinyl ester resin or unsaturated polyester resin Component (a) of the composition for solar cell panel sealing material of the present invention (hereinafter sometimes simply referred to as composition) is a vinyl ester resin or an unsaturated polyester resin. is there.
The vinyl ester resin is specifically selected from urethane (meth) acrylate resin, epoxy (meth) acrylate resin, and polyester (meth) acrylate resin, and is excellent in adhesiveness, heat resistance, and water resistance. An epoxy (meth) acrylate resin is mentioned. In addition, the (meth) acrylate referred to in the present invention refers to acrylate or methacrylate.

Such urethane (meth) acrylate resin is preferably obtained by reaction of polyol, polyisocyanate and (meth) acrylate having one or more hydroxyl groups in one molecule, and two or more (meth) acrylates in one molecule. ) It has an acryloyl group.

The polyol used in the urethane (meth) acrylate resin preferably has a number average molecular weight of 200 to 3000, particularly preferably 400 to 2000.
Typical examples of the polyol include polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene polyols, and the like. These polyols are used alone or in combination of two or more.

As used herein, the polyether polyol may include a polyol obtained by adding the alkylene oxide to bisphenol A and bisphenol F, in addition to a polyalkylene oxide such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

The polyester polyol is a condensation polymer of dibasic acids and polyhydric alcohols or a ring-opening polymer of a cyclic ester compound such as polycaprolactone. Dibasic acids used here are, for example, phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, Hexahydroterephthalic acid, hexahydroisophthalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,12-dodecanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2 , 3-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid anhydride, 4,4′-biphenyldicarboxylic acid, and dialkyl esters thereof. Polyhydric alcohols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, 1,3 -Butanediol, neopentyl glycol, hydrogenated bisphenol A, 1,4-butanediol, 1,6-hexanediol, adducts of bisphenol A and propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, Glycerin, trimethylolpropane, 1,3-propanediol, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, 1,4-cycl Hexane dimethanol, paraxylene glycol, bicyclohexyl-4,4'-diol, 2,6-decalin glycol, and 2,7-decalin glycol, and the like.

Examples of the polyisocyanate used in the urethane (meth) acrylate resin include 2,4-TDI and its isomer or a mixture of isomers, MDI, HDI, IPDI, XDI, hydrogenated XDI, dicyclohexylmethane diisocyanate, tolidine diisocyanate, and naphthalene. A diisocyanate, a triphenylmethane triisocyanate, etc. can be mentioned, These can be used individually or in mixture of 2 or more types.

Examples of the (meth) acrylate (hydroxyl group-containing (meth) acrylate) having one or more hydroxyl groups per molecule used in the urethane (meth) acrylate resin include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl ( Mono (meth) acrylates such as (meth) acrylate, 3-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, tris (hydroxyethyl) isocyanuric acid di (meth) acrylate, And polyvalent (meth) acrylates such as pentaerythritol tri (meth) acrylate.

Examples of the method for producing the urethane (meth) acrylate resin include: (1) First, a polyisocyanate and a polyol are preferably reacted at NCO / OH = 1.3 to 2 to form a terminal isocyanate compound, and then a hydroxyl group is produced. A method of reacting the containing (meth) acrylate so that the hydroxyl groups are approximately equal to the isocyanate group, and (2) reacting the polyisocyanate compound and the hydroxyl-containing (meth) acrylate at NCO / OH = 2 or more, Examples include a method in which a compound of a terminal isocyanate is produced and then a polyol is added to react.

The epoxy (meth) acrylate resin used as the vinyl ester resin preferably has two or more (meth) acryloyl groups in one molecule, and is an esterification catalyst for epoxy resin and unsaturated monobasic acid. It is obtained by reacting in the presence of.

Examples of the epoxy resin mentioned here include a bisphenol type or novolac type epoxy resin alone, or a resin in which a bisphenol type and a novolac type epoxy resin are mixed, and the average epoxy equivalent is preferably 150 to It is in the range of 450.

Here, as a typical example of the bisphenol type epoxy resin, a glycidyl ether type epoxy resin substantially having two or more epoxy groups in one molecule obtained by the reaction of epichlorohydrin and bisphenol A or bisphenol F is used. An epoxy resin, a methyl glycidyl ether-type epoxy resin obtained by reaction of methyl epichlorohydrin and bisphenol A or bisphenol F, an epoxy resin obtained from an alkylene oxide adduct of bisphenol A and epichlorohydrin or methyl epichlorohydrin, or the like. Typical examples of the novolak type epoxy resin include an epoxy resin obtained by a reaction of phenol novolak or cresol novolak with epichlorohydrin or methyl epichlorohydrin.

Typical examples of unsaturated monobasic acids used for epoxy (meth) acrylate resins include acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, monomethyl maleate, monopropyl maleate, and monoester maleate. (2-ethylhexyl) or sorbic acid. These unsaturated monobasic acids may be used alone or in combination of two or more. The reaction between the epoxy resin and the unsaturated monobasic acid is preferably carried out using an esterification catalyst at a temperature of 60 to 140 ° C., particularly preferably 80 to 120 ° C.

As the esterification catalyst, known catalysts such as tertiary amines such as triethylamine, N, N-dimethylbenzylamine, N, N-dimethylaniline or diazabicyclooctane, triphenylphosphine or diethylamine hydrochloride Can be used as is.

The polyester (meth) acrylate resin used as the vinyl ester resin is a saturated or unsaturated polyester having two or more (meth) acryloyl groups in one molecule, and (meth) acrylic at the end of the saturated or unsaturated polyester. the compound is obtained by reacting. The number average molecular weight of such a resin is preferably 500 to 5,000.

The saturated polyester used in the present invention is a condensation reaction between a saturated dibasic acid and a polyhydric alcohol, and the unsaturated polyester is a dibasic acid containing an α, β-unsaturated dibasic acid and a polyhydric alcohol. It is obtained by the condensation reaction. In addition, the resin which made the terminal of unsaturated polyester react with the (meth) acryl compound shall be contained in vinyl ester resin in this invention, and shall be distinguished from the unsaturated polyester resin demonstrated below.

Examples of the saturated dibasic acid herein include the compounds shown in the above-mentioned polyester polyol, and examples of the α, β-unsaturated dibasic acid include maleic acid, maleic anhydride, fumaric acid, and itaconic acid. And itaconic anhydride. Moreover, the compound shown to the term of the said polyester polyol can be mentioned also about polyhydric alcohol.

The (meth) acrylic compound of the polyester (meth) acrylate resin used as the vinyl ester resin includes unsaturated glycidyl compounds, various unsaturated monobasic acids such as acrylic acid or methacrylic acid, and glycidyl esters thereof. is there. Preferably, glycidyl (meth) acrylate is used.

The unsaturated polyester resin is obtained by polycondensing an acid component and an alcohol component by a known method, and the kind thereof is not particularly limited as long as it is known as a thermosetting resin. . As the acid component, for example, unsaturated dibasic acids such as maleic anhydride, maleic acid, fumaric acid and itaconic acid are used. If necessary, use a saturated dibasic acid such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, and sebacic acid, and acids other than dibasic acids such as benzoic acid and trimellitic acid. be able to. Examples of the alcohol component include polyhydric alcohols shown in the above-mentioned polyester polyol section.

Component (b) Vinyl monomer and / or (meth) acrylate monomer Component (b) of the composition of the present invention is a vinyl monomer and / or (meth) acrylate monomer. Specific examples include, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-hydroxyethyl) ) Isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, and tricyclodecane dimethanol di (meth) acrylate.

Others include hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) ) Acrylate, butyl (meth) acrylate, amyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) ) Acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isode (Meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, benzyl (meth) Acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, methoxypolyethylene glycol (Meth) acrylate, methoxypolypropylene glycol (meth) acrylate, dicyclopentadiene (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, tricyclodecanyl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate, diacetone (meth) acrylamide, iso Butoxymethyl (meth) acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, N, N-diethyl (meth) acrylamide, N, N'-dimethylaminopropyl (meth) acrylamide, (meth) acryloylmo Examples include ruphorin and vinyl ethers such as hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, and 2-ethylhexyl vinyl ether.

The component (b) vinyl monomer and / or (meth) acrylate monomer of the composition of the present invention is preferably in view of adhesiveness to an adherend (hereinafter sometimes simply referred to as adhesiveness) and low viscosity expression. A compound (b-1) having a cyclic structure and one ethylenically unsaturated group, and at least one monomer selected from a diacrylate compound (b-2), wherein (b-1) and (b -2) is more preferably used in combination.

(B-1) Compound having a cyclic structure and one ethylenically unsaturated group Component (b-1) used in the present invention is a compound having a cyclic structure and one ethylenically unsaturated group.
Examples of the component (b) include alicyclic structure-containing (meth) acrylates such as isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and dicyclopentanyl (meth) acrylate; Examples include benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, acryloylmorpholine, vinylimidazole, vinylpyridine and the like.
Furthermore, compounds represented by the following formulas (1) to (3) can be given.

(Wherein R ² represents a hydrogen atom or a methyl group, R ³ represents an alkylene group having 2 to 8 carbon atoms, preferably 2 to 5 carbon atoms, R ⁴ represents a hydrogen atom or a methyl group, and p is preferably Shows the number from 1 to 4.)

(Wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ are independent of each other and are H or CH ₃ , and q is an integer of 1 to 5)

Examples of the component (b) include monomers having an N-vinyl group in terms of excellent adhesiveness and low viscosity, such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, N-vinylimidazole. , N-vinylcarbazole and the like. Of these, N-vinylcaprolactam is preferred because of its excellent adhesiveness and low viscosity.

The component (b-2) used in the present invention is a diacrylate monomer.
Examples of the diacrylate monomer used in the present invention include ethylene glycol diacrylate, dipropylene glycol diacrylate (DPGDA), 1,6-hexanediol diacrylate (HDDA), 1,4-butanediol diacrylate, and tetraethylene glycol diacrylate. Examples include acrylate, tripropylene glycol diacrylate (TPGDA), PO-modified neopentyl glycol diacrylate, and modified bisphenol A diacrylate. In terms of transparency, tensile strength, and weather resistance, dipropylene glycol diacrylate and tripropylene glycol diacrylate are preferable.

When (b-1) and (b-2) are used in combination, when the blending ratio is (b-1) + (b-2) = 100 parts by mass, (b-1) is 80 -20 parts by mass, preferably 75-25 parts by mass, and (b-2) is 20-80 parts by mass, preferably 25-75 parts by mass.
When the component (b) and the component (e) are used in the above proportion, the balance between transparency and adhesiveness is excellent.

(C) Denaturant Component (c) used in the present invention is a denaturant.
The component (c) modifier has a function of improving adhesiveness in the composition of the present invention.
Examples of the modifier (c) include a polyol (c-1) having a hydroxyl value of 40 to 330 mgKOH / g; and a polyol (c-) having a hydroxyl value of 40 to 330 mgKOH / g and an acid value of 2 to 20 mgKOH / g. 2); modified rubber (c-3); at least one selected from the group consisting of compound (c-4) having an epoxy equivalent of 150 to 700 g / mol.

(I) The polyol (c-1) having a hydroxyl value of 40 to 330 mgKOH / g will be described.

The hydroxyl value of the component (c) includes a translucent member (in particular, glass or polycarbonate resin) having translucency disposed on the light receiving surface side of the solar cell in the solar cell panel of the present invention, and the solar cell. It contributes to the improvement of the selective adhesiveness with respect to the back surface member (especially polyester resin like polyethylene terephthalate) arrange | positioned at the back surface side. Hereinafter, the translucent member and the back member may be collectively referred to as an “adhered body”.

The (i) polyol (c-1) having a hydroxyl value of 40 to 330 mgKOH / g includes aromatic, aliphatic, polybutadiene, castor oil, polyisoprene, and the like. As long as it is any type, the selective adhesiveness to the adherend is good.
(I) The hydroxyl value is preferably 40 to 330 mgKOH / g from the viewpoint of adhesiveness, and more preferably 150 to 300 mgKOH / g.

(I) As a polyol (c-1) having a hydroxyl value of 40 to 330 mgKOH / g, more preferably, from the viewpoint of selective adhesiveness to an adherend,
(I) Castor oil-based polyol (c-1-1) having a hydroxyl value of 40 to 330 mgKOH / g
(I) Polybutadiene-based polyol (c-1-2) having a hydroxyl value of 40 to 330 mgKOH / g
(I) Polyisoprene polyol having a hydroxyl value of 40 to 330 mgKOH / g or a hydrogenated product thereof (c-1-3)
(I) Epoxy polyol resin (c-1-4) having a hydroxyl value of 40 to 330 mgKOH / g
Is mentioned.

In the present invention, the polyol of component (c) can be used as a mixture of two or more if necessary.

(I) A castor oil-based polyol (c-1-1) having a hydroxyl value of 40 to 330 mgKOH / g will be described.

The “castor oil” is an oil containing a triester compound of ricinoleic acid and glycerin. Usually, it is a natural fat or oil or a processed natural fat or oil, but it may be a synthetic fat or oil if it contains the above compounds. The ricinoleic acid constituting the triester compound contained in this castor oil is preferably contained in an amount of 90 mol% or more of the fatty acids constituting the whole triester compound. Further, the castor oil may be a processed product such as a hydrogenated product (usually hydrogenated to an intercarbon unsaturated bond in the ricinoleic acid skeleton). Usually, castor oil contains 90 mol% or more (including 100 mol%) of the above-described triester compound (in the case of a hydrogenated product, a hydrogenated product of the triester compound).

The “castor oil-based polyol” is an ester compound of ricinoleic acid and / or hydrogenated ricinoleic acid and a polyhydric alcohol. If it has this structure, it may be a polyol obtained by using castor oil as a starting material, or a polyol obtained by using a raw material other than castor oil as a starting material. This polyhydric alcohol is not particularly limited.

Castor oil-based polyols include polyols derived from castor oil and polyols obtained by modifying castor oil.

The polyol derived from castor oil is a glycerin ester in which part of the ricinoleic acid is replaced with oleic acid, and ricinoleic acid obtained by saponifying castor oil is esterified with trimethylolpropane or other short molecular polyols. These are fatty acid ester polyols derived from castor oil, such as a mixture of these and castor oil.

Examples of polyols obtained by modifying castor oil include vegetable oil-modified polyols and modified polyols having an aromatic skeleton (such as bisphenol A). A vegetable oil-modified polyol is obtained by replacing a part of glycerin ester ricinoleic acid with a fatty acid obtained from other plants, for example, higher fatty acids such as linoleic acid, linolenic acid, oleic acid obtained from soybean oil, rapeseed oil, olive oil, etc. It is obtained.

Among the castor oil-based polyols, castor oil-based polyol (c-1-1) having a component (i) hydroxyl value of 40 to 330 mgKOH / g is preferable from the viewpoint of the effect of the present invention.
Further, (i) an aromatic castor oil-based polyol (c) having a hydroxyl value of 40 to 330 mgKOH / g in terms of improving toughness (impact resistance), flexibility, and adhesion to an adherend. 1-1-1) is preferred. More preferably, it is 150 to 240 mg KOH / g.

The component (c-1-1-1) is a modified polyol derived from castor oil having an aromatic skeleton (for example, bisphenol A). The component (c-1-1-1) is commercially available, and examples thereof include “URIC AC series” (Ito Oil Co., Ltd.). Among these, an adduct obtained by adding polyalkylene glycol and bisphenol A to ricinoleic acid has preferable adhesion to an adherend, particularly polycarbonate, glass, and polyester resin, and can be represented by, for example, the following formula (4). .

In the formula (4), m represents an average number of 2 to 5, and n represents an average number of 2 to 5.

Modified polyols derived from castor oil represented by the above formula (4) are, for example, trade names URIC AC-005 (hydroxyl value 194 to 214 mg KOH / mg, viscosity 700 to 1500 mPa · s / 25 ° C.), AC-006 ( Hydroxyl value 168 to 187 mgKOH / mg, viscosity 3000 to 5000 mPa · s / 25 ° C., AC-008 (hydroxyl value 180 mgKOH / mg, viscosity 1600 mPa · s / 25 ° C.), AC-009 (hydroxyl value 225 mgKOH / mg, viscosity 1500 mPa -It can obtain from Ito Oil Co., Ltd. as s / 25 degreeC.

(I) A polybutadiene-based polyol (c-1-2) having a hydroxyl value of 40 to 330 mgKOH / g will be described.

Examples of the polybutadiene-based polyol used in the present invention include homopolymers such as 1,2-polybutadiene polyol and 1,4-polybutadiene polyol, poly (pentadiene / butadiene) polyol, poly (butadiene / styrene) polyol, poly ( Examples thereof include copolymers such as butadiene / acrylonitrile) polyols, and hydrogenated polybutadiene-based polyols obtained by adding hydrogen to these polyols.
Polybutadiene-based polyols are commercially available. For example, “Poly bd R-15HT (hydroxyl value 102.7 mgKOH / mg, Mw1200)” and “Poly bd R-45HT (hydroxyl value 46.6 mgKOH / manufactured by Idemitsu Kosan Co., Ltd.) are available. mg, Mw2800) "and the like.
In view of the effects of the present invention, the hydroxyl value of the (c-1-2) polybutadiene-based polyol is preferably 40 to 330 mgKOH / g, more preferably 40 to 110 mgKOH / g.
(C-1-2) The weight average molecular weight (GPC method) of the polybutadiene-based polyol is preferably 50 to 3000, and more preferably 800 to 1500.

(I) A polyisoprene-based polyol having a hydroxyl value of 40 to 330 mgKOH / g or a hydrogenated product thereof (c-1-3) will be described.

Examples of such component (c-1-3) include Polyip (registered trademark) (hydroxyl-terminated liquid polyisoprene) manufactured by Idemitsu. “Poly ip (registered trademark)” (hydroxyl value 46.6 mg KOH / mg, Mn 2500) is a polyisoprene type liquid polymer having a highly reactive hydroxyl group at the molecular end.
An example of the hydrogenated product is Epole (registered trademark) (hydroxyl-terminated liquid polyolefin) manufactured by Idemitsu. “Epol®” (hydroxyl value 50.5 mg KOH / mg, Mn 2500) is a liquid polyolefin obtained by hydrogenating “Poly ip®”. Almost no double bonds remain in the molecule.

(I) The epoxy polyol resin (c-1-4) having a hydroxyl value of 40 to 330 mgKOH / g will be described.

(I) The epoxy polyol resin (c-1-4) having a hydroxyl value of 40 to 330 mgKOH / g used in the present invention is obtained by reacting an epoxy resin with an active hydrogen compound.

Examples of the epoxy resin used here include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcin, pyrocatechol, and phloroglucinol; dihydroxynaphthalene, biphenol, methylene bisphenol (bisphenol F), methylene bis ( Orthocresol), ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis (orthocresol), tetrabromobisphenol A, 1,3-bis (4-hydroxycumylbenzene), 1,4-bis (4- Hydroxycumylbenzene), 1,1,3-tris (4-hydroxyphenyl) butane, 1,1,2,2-tetra (4-hydroxyphenyl) ethane, thiobisphenol, sulfobis Polyglycidyl ether compounds of polynuclear polyhydric phenol compounds such as enol, oxybisphenol, phenol novolak, orthocresol novolak, ethylphenol novolak, butylphenol novolak, octylphenol novolak, resorcin novolak, bisphenol A novolak, bisphenol F novolak, terpene diphenol; Polyglycidyl ether compound of ethylene oxide and / or propylene oxide adduct of the above mononuclear polyhydric phenol compound or polynuclear polyphenol compound; polyglycidyl ether compound of hydrogenated mononuclear polyhydric phenol compound; ethylene glycol, propylene glycol , Butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, Polyglycidyl ethers of polyhydric alcohols such as methylolpropane, pentaerythritol, sorbitol, bisphenol A-ethylene oxide adduct; maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacin Acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, aliphatic such as endomethylenetetrahydrophthalic acid, aromatic or Homopolymers or copolymers of glycidyl esters of alicyclic polybasic acids and glycidyl methacrylate; glycidyl such as N, N-diglycidylaniline, bis (4- (N-methyl-N-glycidylamino) phenyl) methane Has an amino group Epoxy compounds; vinylcyclohexene diepoxide, dicyclopentanediene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxy Epoxidized products of cyclic olefin compounds such as bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; epoxidized conjugated diene polymers such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymer, triglycidyl isocyanate And heterocyclic compounds such as nurate. In addition, these epoxy resins may be internally crosslinked by a prepolymer of terminal isocyanate.

Among these epoxy resins, biphenol, methylene bisphenol (bisphenol F), methylene bis (orthocresol), ethylidene bisphenol (bisphenol AD), isopropylidene bisphenol (bisphenol A), isopropylidene bis (orthocresol), tetrabromobisphenol A, Excellent adhesion to adherends when bisphenol type epoxy resins such as polyglycidyl ether compounds such as 1,3-bis (4-hydroxycumylbenzene) and 1,4-bis (4-hydroxycumylbenzene) are used It is preferable because of its properties.

(I) An epoxy polyol resin (c-1-4) having a hydroxyl value of 40 to 330 mgKOH / g is obtained by reacting an epoxy group of the epoxy resin with an active hydrogen compound such as a carboxylic acid compound, a polyol or an amino compound. It is what

Examples of the carboxylic acid compound include acetic acid, propionic acid, 2,2-dimethylolpropionic acid, 12-hydroxystearic acid, lactic acid, butyric acid, octylic acid, ricinoleic acid, lauric acid, benzoic acid, toluic acid, cinnamic acid, phenyl Aliphatic, aromatic or cycloaliphatic monocarboxylic acids such as acetic acid and cyclohexanecarboxylic acid, maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, adipic acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, Examples include hexahydro acid and hydroxypolycarboxylic acid.

Examples of the polyol include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,2,4-trimethyl-1,5-pentanediol, 1,6-hexanediol, 2-ethyl-1,6-hexanediol, 1,2-octanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, glycerin, trimethylolpropane, pentaerythritol Like low molecular weight polyols is.

Examples of the amino compounds include dialkylamine compounds such as dibutylamine and dioctylamine; alkanolamine compounds such as methylethanolamine, butylethanolamine, diethanolamine, diisopropanolamine, and dimethylaminopropylethanolamine; morpholine, piperidine, 4-methylpiperazine And heterocyclic amine compounds such as

Among the above active hydrogen compounds, alkanolamine compounds such as diethanolamine are preferable.

Also, the epoxy resin can be chain-extended with a compound having two or more active hydrogen groups such as monoethanolamine and monoisopropanolamine.

When the active hydrogen compound is reacted with the epoxy resin, a normal method of adding the active hydrogen compound to the epoxy resin can be employed. For example, the presence of a known catalyst such as a tertiary amine compound or a phosphonium salt. Below, a method in which both are heated to 60 to 200 ° C. and reacted for 3 to 10 hours can be used.

(I) A preferable hydroxyl value of the epoxy polyol resin (c-1-4) having a hydroxyl value of 40 to 330 mgKOH / g is 100 to 140 mgKOH / g from the viewpoint of the effect of the present invention.

Examples of the epoxy polyol resin (c-1-4) having (i) a hydroxyl value of 40 to 330 mgKOH / g include EPICLON U-125-60BT (hydroxyl value 100 to 140 mgKOH / g) manufactured by DIC Corporation.

(I) A polyol (c-2) having a hydroxyl value of 40 to 330 mgKOH / g and (ii) an acid value of 2 to 20 mgKOH / g will be described.

The polyol (c-2) having a hydroxyl value of 40 to 330 mg KOH / g and (ii) an acid value of 2 to 20 mg KOH / g is aromatic, aliphatic or castor oil-based. However, by satisfying the hydroxyl value of (i) and the acid value of (ii), selective adhesion to adherends (especially polycarbonate resin, glass, polyester resin) (especially adhesion between different materials) is improved. To do.
The hydroxyl value of (i) is more preferably 230 to 300 mgKOH / g.
The acid value of (ii) is more preferably 4 to 15 mg KOH / g.

If (i) and (ii) are satisfied,
As the polyol (c-2) having a hydroxyl value of 40 to 330 mgKOH / g and (ii) an acid value of 2 to 20 mgKOH / g,
(I) a castor oil-based polyol (c-2-1) having a hydroxyl value of 40 to 330 mgKOH / g and (ii) an acid value of 2 to 20 mgKOH / g
Is exemplified.

(I) A castor oil-based polyol (c-2-1) having a hydroxyl value of 40 to 330 mg KOH / g and (ii) an acid value of 2 to 20 mg KOH / g is a polyol derived from castor oil. As disclosed in JP-A-2005-89712, it contains a castor oil-based polyol derived from ricinoleic acid, an acidic phosphate ester compound having a total carbon number of 12 or more, and, if necessary, terpene phenols Polyol compositions can also be used. These can be obtained from Ito Refinery under the trade names URIC H-1262 and H2151U, for example.

The Ito Oil URIC H-1262 is a polyol containing a castor oil-based polyol and an acidic phosphate ester compound having a total carbon number of 12 or more (viscosity: 3,500 to 8,500 mPa · s / 25 ° C., hydroxyl value: 240 to 290 (unit mgKOH / g), acid value: 4 to 15 (unit mgKOH / g)), excellent adhesion to adherends (especially polycarbonate resin, glass, polyester resin), especially metal adhesion ( Excellent adhesion to Al) and hydrolysis resistance.
The Ito Oil URIC H-2151U is a polyol containing a castor oil-based polyol, an acidic phosphate compound having 12 or more carbon atoms and terpene phenols (viscosity: 3,500 to 8,500 mPa · s / 25). ° C, hydroxyl value: 240 to 290 (unit mgKOH / g), acid value: 4 to 15 (unit mgKOH / g)), and adherence to adherends (especially polycarbonate resin, glass, polyester resin) Excellent, especially metal adhesion (particularly adhesion to Al) and hydrolysis resistance.

The modified rubber (c-3) will be described.
Examples of the modified rubber (c-3) used in the present invention include (c-3-1) liquid carboxylated polyisoprene and (c-3-2) carboxylated polybutadiene.

(C-3-1) Carboxylated polyisoprene The carboxylated polyisoprene (c-3-1) used in the present invention is mainly used when adhering the composition of the present invention to an adherend. Improves wettability and improves the adhesion.
Examples of the component (c-3-1) include LIR-420 manufactured by Kuraray as maleated polyisoprene.

(C-3-2) Carboxylated polybutadiene The carboxylated polybutadiene (c) used in the present invention functions to improve adhesion when the composition of the present invention is adhered to an adherend.
Component (c-3-2) is a liquid liquid which is transparent at room temperature, and has a main chain microstructure of polybutadiene consisting of vinyl 1,2-bond type, trans 1,4-bond type, cis 1,4-bond type. It is a polymer. Here, the vinyl 1,2-bond is preferably 30% by weight or less, and if the vinyl 1,2-bond exceeds 30% by weight, the storage stability of the resulting composition is deteriorated. Further, the cis 1,4-bond is preferably 40% by weight or more. If the cis 1,4-bond is less than 40% by weight, the adhesiveness of the resulting composition is lowered, which is not preferable.

The carboxylated polybutadiene (c-3-2) component is obtained by reacting liquid polybutadiene with a carboxyl group-introducing compound, and the ratio of 1,3-butadiene and carboxyl group-introducing compound constituting the liquid polybutadiene is 1,3. -80 to 98% by weight of butadiene and 2 to 20% by weight of the carboxyl group-introducing compound are preferred.

The liquid polybutadiene used in the reaction preferably has a number average molecular weight of 500 to 10,000, more preferably 1,000 to 7,000, and a wide molecular weight distribution. The liquid polybutadiene more preferably has an iodine value measured according to DIN 53241, iodine of 30 to 500 g / 100 g of substance. Furthermore, the liquid polybutadiene preferably has a molecular structure of 70 to 90% cis-double bonds, 10 to 30% trans-double bonds and 0 to 3% vinyl double bonds.

As the carboxyl group-introducing compound, an ethylenically unsaturated dicarboxy compound, for example, an ethylenically unsaturated dicarboxylic acid, its anhydride or monoester can be used. Specific examples of the compound include maleic acid, fumaric acid, itaconic acid, 3,6-tetrahydrophthalic acid, itaconic anhydride, 1,2-dimethylmaleic anhydride, maleic acid monomethyl ester and maleic acid monoethyl ester. be able to. Among these, maleic anhydride is preferable because of safety, economy and reactivity. (Maleed polybutadiene is preferred.)

Production of a polybutadiene / maleic anhydride-addition product comprising polybutadiene and maleic anhydride can be carried out by a known method.

The acid value of maleated liquid polybutadiene according to DIN ISO 3682 is preferably 50 to 120 (mgKOH / g), more preferably 70 to 90 (mgKOH / g). When the acid value is less than 50 (mgKOH / g), the adhesiveness of the resulting composition is lowered, and when it exceeds 120 (mgKOH / g), the viscosity of the obtained composition is increased and workability is lowered.

Furthermore, the maleation rate of the maleated liquid polybutadiene is related to the viscosity, but is preferably 6 to 20%, more preferably 6 to 15%, and still more preferably 7 to 10%.

Further, the viscosity (20 ° C.) of maleated liquid polybutadiene measured by DIN 53214 is preferably 3 to 16 Pa · s, more preferably 5 to 13 Pa · s, and further preferably 6 to 9 Pa · s.

In addition, maleated liquid polybutadiene has a vinyl-double bond of 30% or less, and those having a cis-double bond in the above range have higher flexibility than liquid polybutadiene in which the cis-double bond is less than the above lower limit. And has a high maleation rate (acid value) as described above. Therefore, the obtained composition is rich in adhesiveness and sufficiently polarized, so that it can be made more flexible and the flexibility can be easily adjusted.
Liquid polybutadiene having a cis-double bond less than the above lower limit rapidly increases in viscosity as the maleation rate increases, but those having a cis-double bond in the above range have a small increase in viscosity. Since the viscosity is low as in the above range, the reactivity is increased and workability is improved. Moreover, the composition obtained is excellent in terms of low viscosity expression and adhesiveness.

Examples of commercially available maleated liquid polybutadiene include POLYVEST OC 800S (registered trademark) and 1200S manufactured by Degussa.

The compound (c-4) having an epoxy equivalent of 150 to 700 g / mol will be described.

One form of the compound (c-4) having an epoxy equivalent of 150 to 700 g / mol used in the present invention is a polyepoxy compound (c-4-1) having an epoxy equivalent of 150 to 250 g / mol. .

Examples of the polyepoxy compound (c-4-1) having an epoxy equivalent of 150 to 250 g / mol in the composition of the present invention include mononuclear polyhydric phenols such as hydroquinone, resorcin, pyrocatechol, and phloroglucinol. Polyglycidyl ether compounds of compounds: dihydroxynaphthalene, biphenol, methylene bisphenol (bisphenol F), methylene bis (orthocresol), ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis (orthocresol), tetrabromobisphenol A, 1 , 3-bis (4-hydroxycumylbenzene), 1,4-bis (4-hydroxycumylbenzene), 1,1,3-tris (4-hydroxyphenyl) butane, 1,1,2, -Polynuclear polyphenol compounds such as tetra (4-hydroxyphenyl) ethane, thiobisphenol, sulfobisphenol, oxybisphenol, phenol novolak, orthocresol novolak, ethylphenol novolak, butylphenol novolak, octylphenol novolak, resorcin novolak, terpene phenol Polyglycidyl of polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A-ethylene oxide adduct Ether; maleic acid, fumaric acid, itaconic acid, succinic acid, glu Phosphoric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, Homopolymers or copolymers of glycidyl esters of aliphatic, aromatic or alicyclic polybasic acids such as endomethylenetetrahydrophthalic acid and glycidyl methacrylate; N, N-diglycidylaniline, bis (4- (N- Epoxy compounds having a glycidylamino group such as methyl-N-glycidylamino) phenyl) methane and diglycidylorthotoluidine; vinylcyclohexene diepoxide, dicyclopentanediene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxy Cyclohexa Epoxides of cyclic olefin compounds such as polycarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; epoxidized polybutadiene And epoxidized conjugated diene polymers such as epoxidized styrene-butadiene copolymer, and heterocyclic compounds such as triglycidyl isocyanurate.

Examples of the polyepoxy compound (c-4-1) having an epoxy equivalent of 150 to 250 g / mol used in the present invention include biphenol, methylene bisphenol (bisphenol F), methylene bis (orthocresol), ethylidene bisphenol, isopropyl Ridenbisphenol (bisphenol A), isopropylidenebis (orthocresol), tetrabromobisphenol A, 1,3-bis (4-hydroxycumylbenzene), 1,4-bis (4-hydroxycumylbenzene), 1, Polyphenols of bisphenol compounds such as 1,3-tris (4-hydroxyphenyl) butane, 1,1,2,2-tetra (4-hydroxyphenyl) ethane, thiobisphenol, sulfobisphenol, oxybisphenol, terpene diphenol Glycidyl Jill ether is more preferable in terms of adhesion.

Examples of polyglycidyl ethers of bisphenol compounds having an epoxy equivalent of 150 to 250 g / mol include Adeka Resin EP-4100E (Asahi Denka Kogyo; bisphenol A diglycidyl ether, epoxy equivalent 190).

Another form of the compound (c-4) having an epoxy equivalent of 150 to 700 g / mol used in the present invention is a polyolefin polymer (c-4-2) having an epoxy equivalent of 500 to 700 g / mol. It is. A polyolefin polymer having a hydroxyl group at one end and having an epoxy group introduced is preferred. More preferably, it is liquid.

A specific example of the polymer (c-4) having an epoxy equivalent of 150 to 700 g / mol is Kuraray L-207 (same as KRATON LIQUID ™ L-207 POLYMER). L-207 has a fully saturated skeleton (epoxidized ethylene / propylene / ethylene / butylene-OH structure) having an epoxy equivalent of 590 g / mol, a hydroxyl equivalent of 7000 g / mol, and a glass transition temperature of −53 ° C. It is a coalescence and is preferable in terms of adhesiveness.

(D) Ultraviolet curing agent The composition for solar cell panel encapsulant of the present invention comprises (d) an ultraviolet curing agent as an essential component.

In the composition of the present invention, the oligomer component (for example, vinyl ester resin or unsaturated polyester resin (a)) has a double bond such as a (meth) acryloyl group. Therefore, if an ultraviolet curing agent is added, an ultraviolet fluorescent lamp or It can be easily cured in a short time by ultraviolet irradiation using a high-pressure mercury lamp or the like.

Examples of the ultraviolet curing agent include benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, acetophenone, benzoin, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin-n-butyl ether. Benzoin isobutyl ether, benzyl-1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl1-phenylpropan-1-one, benzyl sulfide, thioxanthone, Examples thereof include bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-chlorothixant and the like.

(Composition ratio of the composition)
In the composition of the present invention, the component (a) is blended in an amount of 10 to 40% by mass from the viewpoint of obtaining water resistance, adhesiveness, transparency and appropriate viscosity. A more preferable blending ratio of component (a) is 15 to 35% by mass in terms of water resistance and adhesiveness.
When the compounding amount of the component (a) exceeds 40% by mass, the adhesiveness and water resistance are deteriorated, and the viscosity of the prepared composition is out of an appropriate viscosity range described below, and the storage stability is deteriorated. Air bubbles are easily generated and a smooth surface cannot be obtained.

In the composition of the present invention, the component (b) is blended in an amount of 30 to 70% by mass from the viewpoints of viscosity, adhesiveness, and transparency. A more preferable amount of component (b) is 40 to 65% by mass from the viewpoint of viscosity, adhesiveness, and transparency.
When the compounding amount of the component (b) exceeds 70% by mass, adhesiveness, water resistance and flexibility are lowered. On the other hand, if it is less than 30% by mass, the adhesiveness is deteriorated, the viscosity of the prepared composition is outside the appropriate viscosity range described below, storage stability is deteriorated, bubbles are easily generated, and a smooth surface is obtained. It becomes impossible.

In the composition of the present invention, the component (c) is blended in an amount of 5 to 40% by mass from the viewpoint of adhesiveness, transparency and viscosity. Further, the blending ratio of the component (c) is 10 to 30% by mass, particularly preferably 10 to 25% by mass in terms of adhesiveness and viscosity.
When the compounding amount of the component (c) exceeds 40% by mass, the adhesiveness and water resistance are deteriorated, the storage stability is deteriorated, bubbles are easily generated, and a smooth surface cannot be obtained. Moreover, if it is less than 5 mass%, adhesiveness will fall.

In the composition of the present invention, the component (d) is a total of 100 masses of the components (a) to (c) from the viewpoint of practical photocuring time (irradiation intensity of 500 mJ / cm ² for 10 seconds or less). 0.1 to 15 parts by mass with respect to the amount. The amount of the component (d) is more preferably 1 to 10 parts by weight, particularly preferably 2 to 5 parts by weight in terms of practical photocuring time (irradiation intensity of 500 mJ / cm ² for 3 seconds or less). Part.
When the amount of component (d) exceeds 15 parts by mass, transparency, adhesiveness and water resistance are deteriorated. Moreover, if it is less than 0.1 mass part, photocuring is inadequate.

The viscosity of the composition of the present invention at 25 ° C. is, for example, 3,000 mPa · s or less, more preferably 100 to 2,000 mPa · s. If the viscosity is within this range, stable storage stability that does not separate with time changes is obtained, bubbles are not easily generated, and smooth surface properties can be obtained.粘度 The viscosity can be measured with a B-type viscometer.

As a method for preparing the composition, for example, components (b) and (c) are added as reactive diluents to component (a) in a container equipped with a stirrer. As an addition method, first, the component (b) is added to the component (a) and sufficiently stirred at room temperature. If the viscosity is too high, stirring may be performed while heating at 100 ° C. or lower. If it exceeds 100 ° C., the vapor generation of the component (b) becomes remarkable, which is not preferable in the working environment. Thereafter, after adding component (c) and stirring, when the liquid temperature reaches room temperature, component (d) is added, and the mixture is sufficiently stirred so as not to remain undissolved.
When adding other components, add them at the end and stir well.
The composition obtained by stirring is rapidly processed or stored in a cool and dark place.

The solar cell panel of the present invention is arranged on one or a plurality of solar cells, a translucent member having translucency arranged on the light receiving surface side of the solar cells, and on the back side of the solar cells. And a sealing material for sealing the solar battery cell between the translucent member and the back surface member, and the sealing material is the tail solar battery of the present invention. It consists of a composition for panel sealing materials.
The solar cell may be any known one, for example, the above-described crystalline solar cell, amorphous silicon solar cell, compound semiconductor solar cell, CuInSe ₂ solar cell, n-type CdS / p-type CuInS _2. Although a photovoltaic cell etc. are mentioned, this invention is not restrict | limited to these.
As the translucent member, glass or polycarbonate resin is preferred in the present invention from the viewpoint that the adhesiveness of the composition is particularly good. Examples of the back member include a fluororesin film and a polyester resin film. From the viewpoint that the adhesiveness of the composition is particularly good, a polyester resin, particularly polyethylene terephthalate (PET) is preferred in the present invention.
In the solar cell panel, the thickness of the sealing material is, for example, 20 to 600 μm, preferably 50 to 400 μm.

As a method for forming the sealing material, for example, the composition for solar cell panel sealing material of the present invention is applied on a light-transmitting member or a back surface member, sandwiched between the light transmitting member and the back surface member, and ultraviolet light is applied. The method of hardening is mentioned.
Coating methods include spin coating, (doctor) knife coating, micro gravure coating, direct gravure coating, offset gravure, reverse gravure, reverse roll coating, (Meyer) bar coating, and die coating A method such as spray coating or dip coating can be preferably applied. For example, a manual spinner (ASS-301 type manufactured by Able Co., Ltd.) can be cited as an apparatus for spin coating.
In the present invention, there is no need for thermocompression bonding as in the case where conventional EVA is used as a sealing material, which is advantageous in terms of manufacturing cost.

Hereinafter, the present invention will be further described with reference to examples and comparative examples, but the present invention is not limited to the following examples.

The raw materials used in the examples and comparative examples are as follows.
Component (a-1) Vinyl ester resin (i) Urethane acrylate Sartomer CN963B80 Urethane acrylate (HDDA blend), Type = Polyester, 60 ° C. viscosity = 1,100, Number of functional groups = 2
(Ii) Polyester acrylate CN292 polyester acrylate manufactured by Sartomer, type = aliphatic polyester, viscosity at 25 ° C. = 630, number of functional groups = 4
(Iii) Epoxy acrylate Sartomer CNUVE151 epoxy acrylate, type = polyester, viscosity at 25 ° C. = 150,000, number of functional groups = 2
(Iv) Aliphatic urethane acrylate manufactured by Sartomer CN966J75 Aliphatic urethane acrylate (IBOA blend), type = polyester, 60 ° C. viscosity = 4,240, 25 ° C. viscosity = 105,000, number of functional groups = 2
Component (a-2) Unsaturated polyester resin RIGOLAC 21E-A-2 (trademark) manufactured by Showa Polymer Co., Ltd.

Component (b-1) Compound having a cyclic structure and one ethylenically unsaturated group (i) N-vinylcaprolactam boiling point 117 ° C. (10 mm Hg) manufactured by BASF
Vapor pressure <0.1 mm Hg (20 ℃)
Flash point 110 ° C
Melting point 35 ℃
Viscosity 3.5 cps (40 ° C)
Component (b-2) Diacrylate monomer (i) Dipropylene glycol diacrylate (DPGDA) manufactured by BASF
(Ii) BASF, tripropylene glycol diacrylate (TPGDA)

Component (c) Modifier (c-1-2) Polybutadiene polyol manufactured by Idemitsu Kosan Co., Ltd., Poly bd R-15HT
Viscosity: 1.5 Pa · s / 30 ° C., hydroxyl value: 102.7 mg KOH / g
(C-1-1-1) Aromatic castor oil-based polyol manufactured by Ito Oil Co., Ltd., URIC (trademark) AC-006, a polyol derived from castor oil represented by the above formula (4), viscosity: 0.7 to 1.5 Pa · s / 25 ° C., hydroxyl value: 194 to 214 mg KOH / g
(C-1-3) Polyisoprene-based polyol manufactured by Idemitsu Kosan Co., Ltd. Polyisoprene type liquid polymer having a highly reactive hydroxyl group at the molecular end (hydroxyl value 46.6 mgKOH / mg, number average) Molecular weight Mn = 2500)
(C-2-1) Castor oil-based polyol Ito Oil URIC H-1262
Polyol containing a castor oil-based polyol and an acidic phosphate ester compound having a total carbon number of 12 or more Viscosity: 3,500 to 8,500 Pa · s / 25 ° C., acid value: 4 to 15 (unit mgKOH / g), hydroxyl value : 240-290 (unit mgKOH / g)
(C-2-1) Castor oil-based polyol Ito Oil URIC H-2151U
A polyol containing a castor oil-based polyol, an acidic phosphate ester compound having 12 or more carbon atoms and terpene phenols Viscosity: 3,500 to 8,500 Pa · s / 25 ° C., acid value: 4 to 15 (unit: mgKOH / g), hydroxyl value: 240 to 290 (unit: mgKOH / g)
(C-1-3) Hydrogenated polyisoprene polyol manufactured by Idemitsu Kosan Co., Ltd. Epol (trademark) hydroxyl terminated liquid polyolefin (viscosity (Pa · s / 30 ° C) 75, hydroxyl value (mgKOH / g) 50.5, number average Molecular weight 2500)
(C-3-1) Maleinized polyisoprene Kuraray LIR-420 (acid value (mgKOH / g) 40)
(C-3-2) Maleic acid-modified polybutadiene
SARTOMER Ricon130MA8 (viscosity (Pa · s / 30 ° C) 6.5, acid value (mgKOH / g) 46, number average molecular weight 2700)
(C-3-2) Maleic acid-modified polybutadiene
POLYVEST (trademark) OC 800 S manufactured by EVONIK (1,4-cis double bond in polybutadiene: 75%, 1,4-trans double bond: 24%, vinyl bond: 1%, maleation ratio: 7.5 %, Number average molecular weight: 3300 (GPC), weight average molecular weight: 13,600 (GPC), viscosity (20 ° C.): 6 to 9 Pa · s (measured with DIN 53214), acid value: 70 to 90 mg KOH / g, iodine Value: 380 to 420 g / 100 g, (polymerized with Ziegler-Natta catalyst)
(C-1-4) Epoxy polyol resin
DIC Corporation EPICLON (trademark) U-125-60BT
(Viscosity (Pa · s / 30 ° C) 70, hydroxyl value (mgKOH / g) 120)
(C-4-1) Polyepoxy compound Adeka Resin EP-4100E having an epoxy equivalent of 150 to 250 g / mol (Asahi Denka Kogyo; bisphenol A diglycidyl ether, epoxy equivalent 190)
(C-4-2) Polymer having a saturated skeleton having an epoxy equivalent of 500 to 700 g / mol L-207 manufactured by Kuraray (same as KRATON LIQUID ™ L-207 POLYMER) (Epoxy equivalent is 590 g / mol, Hydroxyl equivalent weight is 7000 g / mol, glass transition temperature -53 ° C, polymer with fully saturated skeleton (epoxidized ethylene / propylene / ethylene / butylene-OH structure)

The characteristics of each polyol were measured as follows.
-Viscosity measurement method The viscometer is measured using a single cylindrical rotational viscometer (B type TVC--5) according to JIS K7117-1.
1. A 500ml beaker (standard) is used for the measuring instrument.
2. Standard rotor is selected from two types: M1 to M4 rotors for low and medium viscosity and H1 to H7 rotors for medium and high viscosity. Hydroxyl value measurement method Hydroxyl value is included in 1g of sample. This is the number of mg of potassium hydroxide required to acetylate the OH group. According to JIS K 1557-1, OH groups in the sample are acetylated using acetic anhydride, and acetic acid not used is titrated with potassium hydroxide solution.

A: Amount of 0.5 mol / l potassium hydroxide ethanol solution used for the blank test (ml)
B: 0.5mol / l potassium hydroxide ethanol solution used for titration (ml)
f: Factor

-Acid value measuring method It represents with the mg number of potassium hydroxide required to neutralize the acidic component contained in 1g of sample oils. According to JIS K 1557-5,
(1) End-point pH measurement Take 10 mL of buffer stock solution B in a 200-mL beaker, add 100 mL of titration solvent, immerse the electrode, and use the pH that changes within 0.1 pH within 30 seconds as the buffer end point.
(2) Measurement of acid value 1. Weigh accurately 20 g of sample into a 200 mL beaker.
2. Add 125mL of toluene / 2-propanol / pure water mixed solvent and titrate with 0.1mol / L potassium hydroxide titrant.
Result of (1) 11.72 Set pH as the end point and calculate the acid value by the following formula. Moreover, a blank is calculated | required in the same procedure.
Acid value (mgKOH / g) = (D−B) × K × F × M / S
D: Titration value (mL)
B: Blank (0.085mL)
K: Molecular weight of KOH (56.1)
F: Factor of titrant (1.000)
M: Molar concentration of titrant (0.1 mol / L)
S: Sampling amount (g)

Component (d) Component UV curing agent manufactured by CIBA, IRGACURE ™ 819, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide

Examples 1 to 20 and Comparative Examples 1 to 6
In the blending ratio (parts by mass) shown in Tables 1 to 7 below, the component (a) is put into a container equipped with a stirrer, then the component (b) is added, and the mixture is sufficiently stirred at room temperature. After adding c) and stirring, when the liquid temperature reached room temperature, the component (d) was added, and the mixture was sufficiently stirred so as not to remain undissolved to obtain a composition. The viscosity (mPa · s) at 25 ° C. of the obtained composition was measured. That is, using a handy type digital viscometer TVC-7 type viscometer (Toki Sangyo Co., Ltd.), the viscosity at 25 ° C. was measured using an appropriate rotor (No. 0 to No. 5) according to the viscosity. The results are also shown in Tables 1 to 7.

Next, on each adherend shown in Tables 1 to 7 (dimensions: 150 mm × 25 mm × thickness 1 mm), the composition was applied by spin coating (coating thickness 15 to 20 μm), and this was applied under air to 500 mJ. A laminate was prepared by irradiating with UV light having an energy of / cm ² to be cured.

Each adherend used is as follows.
・ Polycarbonate PC (trade name Panlite L-1225L, manufactured by Teijin Chemicals Ltd.)
・ Glass (slide glass for microscope preparation)
・ PET: Unitika Unitika polyester resin MA-2103

Transparency test (measurement of haze value and total light transmittance)
Using a laminate using glass as the adherend, measurement was performed using a measuring instrument (trade name “COH-300A”) manufactured by Nippon Denshoku Industries Co., Ltd.

Adhesion test The obtained laminate was subjected to the following cross-cut tape test.
(Adhesion test: cross-cut tape test)
The measurement was performed as follows in accordance with the cross cut tape test method described in Japanese Industrial Standard K5400.
Cross-cut test (Cross-cut Test, coating thickness 15-20 μm (spin coating method)): A 1 × 1 mm square cut is made on the test surface (the layer side of the composition) using a cutter knife. Use the cutter guide. The number of grids is 10 vertical x 10 horizontal = 100. Strongly press the cellophane tape into the grid, and peel off the end of the tape rapidly at an angle of 45 ° to see the grid pattern (number of grids remaining without peeling).

Water Resistance Test Each laminate was immersed in boiling water (pure water) for 1 hour and then naturally dried indoors, and visually observed for deterioration of the appearance of the composition layer.
○: No peeling or cracking (immersion for 1 hour)
×: Peeling or cracking occurred (immersion for 1 hour)

Adhesion test between different materials An adhesion test between different materials was performed by measuring the shear adhesive strength as shown below.
On the polyester resin (B1) having dimensions of 150 mm × 1 mm thickness × 25 mm width, the composition is applied by spin coating (coating thickness: 15 to 20 μm) to form a layer (A) of the composition. The glass or polycarbonate layer (B2) having the same dimensions as the above (B1) shown in Tables 1 to 7 is pressure-bonded, and UV irradiation (wavelength: 325 nm, integrated irradiation intensity) from the layer (B2) (glass or polycarbonate layer) side is applied. 50 mJ / cm ² ) and UV-cured to prepare a laminate, and then the layer (B2) is pulled in a direction parallel to the bonding surface of the layer (A) of the composition to obtain a tensile strength at break. It was measured.
The results are shown in Tables 1-7. In Tables 1 to 7, the laminate composed of (B1)-(A)-(B2) is shown as (B1) vs (B2). For example, when (B1) is a polyester resin (PET) and (B2) is glass, it is shown as “polyester resin (PET) vs glass”.

Weather resistance test Each laminate was exposed to 2000 hours in a cycle of 12 minutes of rain and 48 minutes of drying at a black panel temperature of 63 ° C. using a sunshine weather meter, and the appearance was evaluated.
○: No change in appearance ×: Whitening, yellowing, peeling

Flexibility test method: Each laminate was subjected to a 90-degree bending test and evaluated according to the following criteria.
○: Not peeled Δ: Partially peeled / cracked X: Whole surface peeled / cracked The results are shown in Tables 1-7.

As is apparent from the table, in Examples 1 to 20 of the present invention, the components (a), (b), (c) and (d) are contained in a specific quantitative relationship. Translucent member placed on the light-receiving surface side of the cell, especially glass or polycarbonate, and back side member placed on the back side, especially excellent adhesion to polyester resin such as polyethylene terephthalate, excellent water resistance Yes. It is also excellent in transparency, flexibility, tensile strength, and weather resistance.
On the other hand, in Comparative Example 1, since the amount of component (b) added exceeded the upper limit defined in the present invention, the adhesiveness deteriorated, and the water resistance and flexibility also deteriorated.
In Comparative Example 2, since the amount of component (a) added exceeded the upper limit defined in the present invention, the adhesiveness deteriorated and the water resistance also deteriorated.
Since the comparative example 3 did not add the component (c), adhesiveness deteriorated and water resistance also deteriorated.
In Comparative Example 4, the amount of component (c) added exceeded the upper limit defined in the present invention, and the adhesion, water resistance, and foreign material adhesion deteriorated.
In Comparative Example 5, since the amount of component (d) added was less than the lower limit specified in the present invention, the composition was not cured.
In Comparative Example 6, since the amount of component (d) added exceeded the upper limit defined in the present invention, the adhesiveness deteriorated and the water resistance also deteriorated.

Claims (12)

1. (A) Vinyl ester resin or unsaturated polyester resin 10 to 40% by mass
   (B) Vinyl monomer and / or (meth) acrylate monomer 30 to 70% by mass
   (C) modifying agent 5-40% by mass,
   (However, the total of the components (a) to (c) is 100% by mass)
   And (d) an ultraviolet curing agent A composition for a solar cell panel encapsulant containing 0.1 to 15 parts by mass with respect to a total of 100 parts by mass of the components (a) to (c).
2. The composition for a solar cell panel encapsulant according to claim 1, wherein the component (a) is an epoxy (meth) acrylate.
3. The composition for a solar cell panel sealing material according to claim 1 or 2, wherein the component (b) is a monomer having an N-vinyl group.
4. The component (c) is a polyol (c-1) having a hydroxyl value of 40 to 330 mgKOH / g; and a polyol (c-2) having a hydroxyl value of 40 to 330 mgKOH / g and an acid value of 2 to 20 mgKOH / g The modified rubber (c-3) is at least one selected from the group consisting of the compound (c-4) having an epoxy equivalent of 150 to 700 g / mol. The composition for solar cell panel sealing materials as described in any one of.
5. The component (c-1) is a castor oil-based polyol (c-1-1) having a hydroxyl value of 40 to 330 mgKOH / g; a polybutadiene-based polyol (c-1-2) having a hydroxyl value of 40 to 330 mgKOH / g; The solar cell panel seal according to claim 4, which is at least one selected from the group consisting of a polyisoprene-based polyol having a value of 40 to 330 mgKOH / g or a hydrogenated product thereof (c-1-3). Stopping composition.
6. The solar cell panel seal according to claim 5, wherein the component (c-1) is an aromatic castor oil-based polyol (c-1-1-1) having a hydroxyl value of 40 to 330 mgKOH / g. Stopping composition.
7. The component (c-2) is a castor oil-based polyol (c-2-1) having a hydroxyl value of 40 to 330 mgKOH / g and an acid value of 2 to 20 mgKOH / g. 4. The composition for solar cell panel sealing material according to 4.
8. The composition for a solar cell panel sealing material according to claim 4, wherein the component (c-3) is acid-modified polybutadiene or acid-modified polyisoprene.
9. The composition for solar cell panel sealing material according to claim 4, wherein the component (c-4) is a polyepoxy compound (c-4-1) having an epoxy equivalent of 150 to 250 g / mol. .
10. The solar cell panel sealing material according to claim 4, wherein the component (c-4) is a polymer (c-4-2) having a saturated skeleton having an epoxy equivalent of 500 to 700 g / mol. Composition.
11. Single or multiple solar cells;
    A translucent member having translucency disposed on the light-receiving surface side of the solar battery cell;
    A back member disposed on the back side of the solar cell;
    In a solar battery panel comprising: a sealing material that seals the solar battery cell between the translucent member and the back member;
    A solar cell panel, wherein the encapsulant comprises the composition for a solar cell panel encapsulant according to any one of claims 1 to 10.
12. The solar cell panel according to claim 11, wherein the translucent member is glass or polycarbonate resin, and the back member is a polyester resin.