JP2006269844A - Composition of protective coating agent for end part of solar cell module and method for manufacturing solar cell module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sealing material excellent in stability to adhesiveness, light, humidity, heat, and heat cycles or the like as a protective coating agent for the end of solar cell module, and also to provide a method for manufacturing the solar cell module using the same. <P>SOLUTION: The composition of the protective coating agent for the end of the solar cell module is composed of (A) a thermoplastic resin, (B) wax, and (C) an adhesion imparting resin. Namely, the composition is composed of (B) 5-70 pts.wt. of the wax, and (C) 10-300 pts.wt. of the adhesion imparting resin based on (A) 100 pts.wt. of the thermoplastic resin. The softening point temperature (Tm) by JIS K-2207 of the composition is 100-160°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an adhesive resin sealing material used for sealing a solar cell module formed on a substrate with a protective material, and a method for manufacturing a solar cell module using the adhesive resin sealing material.

Currently, clean energy research and development is underway from the standpoint of environmental protection. Among them, solar cells are attracting attention because their resources (sunlight) are infinite and pollution-free. A typical example of a solar cell in which a plurality of solar cell modules formed on the same substrate are connected in series or in parallel is an amorphous thin film solar cell. The thin-film solar cell is considered to become the mainstream of future solar cells because it is thin and lightweight, low in manufacturing cost, and easy to increase in area, etc. Demand is also expanding for business use and general residential use. Roof tiles with solar cells have also been developed for general housing.
The module using the above-mentioned thin film solar cell has a plurality of solar cell elements connected in series or in parallel, a surface protective member such as a glass plate on the light receiving side, and ethylene monofluoride on both sides of the aluminum foil on the back side. Adhesive resin sealing such as EVA (ethylene-vinyl acetate copolymer resin), which is provided with a back surface protective member such as a moisture-proof protective sheet to which (trade name: Tedlar, manufactured by DuPont) is bonded, is excellent in adhesive sealing and inexpensive. It is heat-sealed and sealed with a stopper. A solar cell module using a surface protection member such as a glass plate is provided with a frame around it, and the periphery of the solar cell module is inserted into a holding portion having a U-shaped frame of a metal frame. It is fixed and held by an adhesive protective agent injected so as to fill the gap. Here, as the adhesive protective agent, an adhesive elastic sealing material such as butyl rubber or liquid silicone rubber that is solid after curing is used (Patent Documents 1 and 2), and a surface protective member such as a glass plate or a frame is used. Absorbs thermal expansion and suppresses moisture intrusion. When butyl rubber is used as an adhesive protective agent, it is difficult to automate the work, so there is a problem in mass productivity. When silicone rubber that is liquid and becomes solid after curing is used, the workability of mixing two liquids is poor. Then, there is a problem that a long time of 24 hours or more is required for curing.
Japanese Examined Patent Publication No. 62-14111 JP 2003-298092 A

  The present invention solves the above problems, and as an end protection coating agent for solar cell modules, it has excellent adhesion, stability to light, moisture, heat, heat cycle, etc., and is excellent in mass productivity of solar cell modules. Providing a resin sealing material. Furthermore, it is providing the manufacturing method of a solar cell module using the same.

As a result of diligent research to solve the above problems, a module end protective coating composition for solar cells comprising (A) a thermoplastic resin, (B) a wax, and (C) a tackifying resin was invented. That is, (A) softening point temperature according to JIS K-2207 (B) consisting of 5 to 70 parts by weight of wax and (C) 10 to 300 parts by weight of tackifying resin (100 parts by weight of thermoplastic resin) Tm) is a solar cell module end protective coating agent composition having a temperature of 100 to 160 ° C. Further, (A) the thermoplastic resin is preferably at least one selected from an olefin resin, a rubber resin, a polyamide resin, a polyester resin, a polyurethane resin, and a silicone resin, and (B) the wax is polypropylene and / or polyethylene. (C) The tackifier is preferably at least one selected from petroleum resins, terpene resins, and rosin resins.
Moreover, it is a manufacturing method of the solar cell module which uses the said module edge part protective coating agent composition for solar cells, and is a solar cell manufactured by it.

  According to the present invention, as an end portion protective coating agent for a solar cell module, a resin sealing material excellent in adhesiveness, stability to light, moisture, heat, heat cycle, etc., and excellent in mass productivity of solar cell modules is obtained. be able to.

Hereinafter, the present invention will be described in detail.

[(A) Thermoplastic resin]
(A) The thermoplastic resin is polyethylene, ethylene vinyl acetate copolymer, ethylene / ethylene acrylate copolymer, polypropylene, atactic polypropylene, ethylene / methyl methacrylate copolymer, ethylene / acrylic acid copolymer, ethylene・ Olefin resins such as methacrylic acid copolymer, ethylene / polyvinyl alcohol copolymer, ethylene / ethyl acrylate / maleic anhydride copolymer, metal salt of ethylene / methacrylic acid copolymer, ethylene / propylene copolymer Polymer, ethylene / butylene copolymer, ethylene / propylene copolymer, ethylene / propylene / diene copolymer, styrene / butadiene / styrene copolymer, styrene / isoprene / styrene copolymer, styrene / ethylene and butylene / Styrene block copolymer Butyl rubber, isobutylene-isoprene copolymers, polybutadiene, rubber-based resins such as isoprene rubber, polyamide resins, polyester resins, polyurethane resins, those of at least one selected from silicone resins.
Of these, olefin resins, rubber resins, polyamide resins, polyester resins, polyurethane resins, and silicone resins are preferable, and styrene / butadiene / styrene copolymers and styrene / isoprene / styrene copolymers are more preferable. is there.
The thermoplastic resin used in the present invention may contain a thermosetting resin or the like as long as the object of the present invention is not impaired.

[(B) Wax]
Specific examples of the (B) wax of the present invention include paraffin wax, microcrystalline wax, polypropylene wax, and polyethylene wax. Polypropylene wax and polyethylene wax are preferred. These can be used alone or in combination of two or more.
The softening point temperature of the wax used in the present invention according to JIS K-2207 is not particularly limited, but is preferably 65 ° C to 160 ° C, and more preferably 80 ° C to 150 ° C. When the softening point temperature is 65 ° C. or higher, heat-resistant adhesion is improved, and when it is 160 ° C. or lower, the viscosity can be lowered during melting or solvent dilution, and workability is improved.
(B) The amount of wax used is 50 to 70 parts by weight, preferably 10 to 50 parts by weight, in terms of adhesion and workability, with respect to 100 parts by weight of the thermoplastic resin (A).

[(C) Tackifier]
The (C) tackifier of the present invention includes polybutene, liquid polybutadiene, aliphatic C5 petroleum resin, aromatic C9 petroleum resin, C5C9 copolymer petroleum resin, dicyclopentadiene petroleum resin, hydrogenated petroleum resin and the like. Selected from petroleum resins, polyhydroxy polyolefins, terpenes, terpene phenols, rosin phenols, terpene resins such as aromatic modified terpenes, hydrogenated terpenes, rosin resins such as modified rosins, methyl esters, glycerin esters, pentaerythritol esters At least one type.
Among these, hydrogenated petroleum resins, terpene phenols, and hydrogenated terpenes are preferable.
(C) The usage-amount of a tackifier is 10-300 weight part with respect to 100 weight part of said (A) thermoplastic resins, Preferably it is 50-200 weight part.

[(D) Other additives]
In the present invention, a coupling agent, a pigment, a dye, an inorganic filler, an antioxidant, an organic peroxide, a diluent, a plasticizer, and the like can be used as necessary.
The organic peroxide is preferably used for heat modification to impart heat resistance. Any organic peroxide capable of imparting heat resistance can be used. Specifically, for example, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5- Di (t-butylperoxy) -3-hexyne and the like can be mentioned.
Diluents can be used to impart or improve coatability. As the diluent, an organic solvent is usually used. Although there is no particular limitation on the physical properties of the organic solvent, a compound or mixture having a boiling point of 200 ° C. or lower at atmospheric pressure is preferable, a boiling point of 150 ° C. or lower is more preferable, and 70 ° C. or higher and 130 ° C. or lower is more preferable. These diluents can be used alone or in combination of two or more, and the amount used is not particularly limited, and the amount is selected according to the coating suitability. These include alcohols, glycol ethers, ethylene glycol ether acetates, aromatic hydrocarbons, ketones, esters, ethers and the like. Specific examples of these compounds include the following.

Examples of alcohols include methanol, ethanol, propanol, butanol and the like. Examples of glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and the like. Examples of ethylene glycol ether acetates include ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and the like. Aromatic hydrocarbons include toluene, xylene and the like. Examples of ketones include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone and the like. Esters include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and the like. Examples of ethers include tetrahydrofuran.
The plasticizer is preferably added to impart or improve flexibility. Any plasticizer that can impart and improve flexibility can be used without any particular limitation. Specific examples include liquid polybutene, low molecular weight polyisobutylene having a molecular weight of 5000 to 12000, paraffinic oil, naphthenic oil, process oil, and linear aliphatic acid esters.
The filler is preferably added in order to make the heat shrinkage rate in an appropriate range. Further, it may be used as a bulking agent as long as the effect of the present invention is not impaired. Any filler can be used as long as the module end protective coating agent composition for solar cells satisfies the above-described physical properties, and further can have a heat shrinkage rate within a predetermined range, and there is no particular limitation. Specific examples include silica, alumina, barium sulfate, calcium carbonate, titanium oxide, carbon black, and talc.
The antioxidant is preferably added to prevent thermal deterioration. Any antioxidant can be used as long as it can prevent thermal degradation, and there is no particular limitation. Specific examples include hindered phenol compounds and phosphate ester compounds.

  The softening point temperature (Tm) according to JIS K 2207 of the module end protective coating agent composition for solar cells of the present invention is 100 to 160 ° C., preferably 120 to 150 ° C. in terms of heat resistance and workability.

[Method for producing module end protection coating composition for solar cell]
Production of solar cell module end protection coating composition is a powerful stirring and mixing device such as (A) thermoplastic resin, (B) wax, (C) tackifying resin under nitrogen atmosphere, such as sigma blade type kneader There is no particular limitation. Generally, after mixing uniformly for 1 to 3 hours at a temperature in the range of 120 to 200 ° C., the solid resin is obtained by cooling.
The method for forming the protective coating layer of the solar cell module in the present invention is roughly classified into the following two.
(1) A method of applying the composition for a protective coating of the present invention to a cell end portion for a solar battery using a hand gun and a hot melt applicator.
(2) A method of applying or installing a molded product obtained by molding the protective coating composition of the present invention into a desired shape using a hand gun or a hot melt applicator.
In the case of (1), the aluminum frame may be installed immediately after coating, and then cooled and solidified, or reheated and solidified.
In the case of (2), after installing the aluminum frame, reheat and solidify.

The edge part of the cell for solar cells can be sealed using the protective coating agent composition of this invention.
Moreover, a solar cell module can be manufactured by heating and melting this protective coating agent composition and applying it to a protective frame of a solar cell.
Moreover, a solar cell module can be manufactured by heating and melting the protective coating agent composition and applying it to the end of the solar cell.
Furthermore, a solar cell module can be manufactured by installing a protective frame immediately after applying the protective coating agent composition.

Moreover, after installing a protective frame in a photovoltaic cell, it heats at 50-160 degreeC, a protective coating agent composition can be fuse | melted, and a solar cell module can be manufactured.
The protective coat layer thus obtained has excellent moisture permeation resistance, excellent flexibility, toughness, and adhesive properties, and can maintain photoelectric conversion efficiency even under high temperature and high humidity.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Evaluation methods]
Evaluation was performed by the following test methods.
1. Moisture permeability A moisture-proof coating film adjusted to a thickness of 100 μm using a moisture-proof coating composition adjusted to a moisture permeability test is a temperature of 40 ° C. and a humidity of 90 according to JIS Z-0208 (a moisture permeability test method for moisture-proof packaging materials). The moisture permeability under the condition of% was measured.
2. Softening point temperature It measured by the ring and ball method according to JIS K-2207 using the module edge part protective coating agent composition for solar cells adjusted to the softening point measurement test.
3. Adhesion test The shear strength of the test piece which bonded glass (JIS R-3202) using the solar cell module edge part protective coating agent composition adjusted to the adhesive force test was measured.
4). Workability The workability when a protective coat layer was prepared by the method described in the method of use (1) using the solar cell module end protective coating agent adjusted for the workability test was evaluated in three stages.
○: Good workability Δ: Workability is bad ×: Work is extremely bad Strain, cracking of panel after forming protective coating layer Solar cell module edge adjusted to 4 pieces using solar cell module edge protective coating agent formation test module to evaluate flexibility and cure shrinkage A protective coating layer was formed using the partial protective coating agent composition. The distortion and cracking of the panel after forming the coating layer were evaluated in three stages.
○: No abnormality in the appearance Δ: The cell is distorted ×: The cell is cracked High temperature and high humidity test 3. The photoelectric conversion efficiency of the cell provided with the solar cell module end protection coating agent prepared in the adhesion test and the photoelectric conversion efficiency after being left in an environment of 60 ° C. and 95% for 500 hours were observed, and the following three stages Was evaluated.
○: Good with no change from the initial state Δ: Slightly decreased ×: Clearly decreased.

[Raw materials used]
<(A) Thermoplastic resin>
(A-1) Clayton G-1762X (manufactured by Shell Japan)
(A-2) Butyl 065 (Nippon Butyl)
<(B) Wax>
(B-1) Biscol 660P (manufactured by Sanyo Chemical)
(B-2) EP-11 (JSR)
<(C) Tackifier>
(C-1) YS Polystar T130 (Yasuhara Chemical)
(C-2) Escorets 5320 (manufactured by Tonex)
<Plasticizer>
Plasticizer-1 Nisseki Polybutene HV-1900 (Nippon Petroleum)
<Antioxidant>
Antioxidant-1 Irganox 1010 (manufactured by Ciba Specialty Chemicals)
<Coupling agent>
Silane coupling agent SH-6040 (Toray Dow Corning Silicone)
<Epoxy resin>
Epoxy resin EP4000 (Asahi Denka) /m-xylylenediamine=86.5/13.5
<Silicone resin>
(Silicone resin) SE9175 (made by Toray Dow Corning Silicone).

[Example 1]
The compound composition shown in Table 1 was kneaded for 1 hour in a melt kneader under a nitrogen atmosphere, and then cooled and adjusted to obtain a module end protective coating agent composition for solar cells. Using the prepared protective coating composition, a moisture permeability test, an adhesion test, a moisture-proof coating film formation test on the cell, and a high-temperature and high-humidity test of the cell were performed in order to evaluate flexibility and cure shrinkage. The results are shown in Table 1.

[Example 2 to Comparative Example 2]
The moisture-proof coat layer was evaluated according to Example 1 except that the composition shown in Table 1 was used. The results are shown in Table 1.

Claims (10)

(A) Thermoplastic resin For 100 parts by weight,
(B) End protection of a module for a solar cell comprising 5 to 70 parts by weight of wax and (C) 10 to 300 parts by weight of a tackifying resin and having a softening point temperature (Tm) of 100 to 160 ° C. according to JIS K-2207 Coating agent composition. 2. The solar cell module according to claim 1, wherein the thermoplastic resin (A) is at least one selected from an olefin resin, a rubber resin, a polyamide resin, a polyester resin, a polyurethane resin, and a silicone resin. Edge protective coating composition. 3. The module end protective coating agent composition for solar cell according to claim 1 or 2, wherein the wax (B) is polypropylene and / or polyethylene. The module end for solar cell according to any one of claims 1 to 3, wherein the (C) tackifier is at least one selected from petroleum resins, terpene resins, and rosin resins. Protective coating agent composition. The manufacturing method of the solar cell module characterized by sealing the edge part of the cell for solar cells using the protective coating agent composition in any one of Claims 1-4. The method for producing a solar cell module according to claim 5, wherein the protective coating agent composition according to any one of claims 1 to 4 is heated and melted and applied to a protective frame of a solar cell. The method for producing a solar cell module according to claim 5, wherein the protective coating agent composition according to any one of claims 1 to 4 is heated and melted and applied to an end portion of a cell for solar cells. A method for producing a solar cell module, comprising: installing a protective frame immediately after applying the protective coating composition by the method according to claim 6 or 7. After installing a protection frame in a photovoltaic cell, it heats at 50-160 degreeC, The manufacturing method of the solar cell module characterized by melting the protective coating agent composition in any one of Claims 1-4 . The solar cell manufactured by the manufacturing method of the solar cell module of Claim 5.