JP6540560B2 - Method of manufacturing solar cell module - Google Patents

Description

The present invention relates to a method of manufacturing a solar cell module of the flame retardant.

  In general, a solar cell module has a light transmitting substrate such as glass or polycarbonate on the light receiving surface side, and a back surface protective material such as a light transmitting substrate similar to the light receiving surface on the back surface side or a PET film EVA (ethylene-vinyl acetate copolymer, polyolefin, ionomer, etc.) is used as the sealing material.

  Since these sealing materials are flammable resins, the reduction of combustibility is an issue. In particular, when used for a residential roof, the flame caused by the splinter causes the light transmitting substrate on the light receiving surface side, for example, glass, to crack, and the solar cell module continues to burn by igniting an encapsulant such as EVA. The phenomenon occurs.

  In addition, if the solar cell module continues to burn, the back sheet is mainly made of PET, so combustion can not be stopped, combustion holes are generated in the back sheet, and fragments of glass and cells fall to the bottom There is.

  When installing a solar cell module on the roof of a house, it is necessary to pass a test based on laws and regulations on fire protection, and the flame caused by the above-mentioned sparks causes the solar cell module to penetrate and spread, resulting in burnables, glass, and power generating elements It may not reach the passing of this test that the fragments etc. of it fall to the lower part.

  In addition, when a light transmitting film is used on the light receiving surface side and the back surface side as seen in a flexible thin film solar cell, the light transmitting film spreads fire and fire holes are generated by the flame due to the spark. In the case where the sealing material such as EVA is ignited, the solar cell module continues to burn, and finally, a phenomenon in which the combustion material falls to the lower part occurs.

As a measure for solving such a problem, there is a method of adding a chlorine-based or red phosphorus-based flame-retardant material to the cell back side sealing material of a solar cell (Patent Document 1).
In addition, a method of adding a flame retardant such as intomescent ammonium phosphate which suppresses combustion by heat insulation to a sealing material (Patent Document 2), or a sealing material such as nano clay, hydrous magnesium silicate, calcium carbonate, etc. Methods of adding nanoparticles and the like have been disclosed (Patent Document 3).

The method of adding chlorine and red phosphorus to the sealing material in Patent Document 1 is not preferable because dioxins may be generated at the time of combustion.
In the method of adding a flame retardant such as intomescent ammonium phosphate as described in Patent Document 2 to the encapsulant, the particle size of the intomescent material is large, and it is transmitted when it is added to the encapsulant It has the disadvantage of reducing the rate.
The method of adding nanoparticles such as nanoclay, hydrous magnesium silicate, calcium carbonate and the like in Patent Document 3 may impair the permeability of the encapsulant unless the dispersion state of the particles is properly controlled.

JP-A-9-27633 Unexamined-Japanese-Patent No. 2007-335853 JP, 2011-134986, A

The present invention has been made to solve the above problems, a solar cell module process is easy, and a good laminate sealing is obtained, to provide a method of manufacturing a solar cell module excellent in flame retardancy To aim.

  As a result of intensive investigations to achieve the above object, the present inventors are effective in laminating a silicone layer on the outer surface of the light transmitting substrate or the light transmitting film or the back surface protective material on the back of the solar cell module. Found out.

  As a solar cell sealing material, although EVA, polyolefin, an ionomer, etc. are generally used, it is possible to improve a flame retardance by partially applying silicone to such resin. The structure may be a laminate of EVA, polyolefin, ionomer, etc. and silicone, or may be a structure in which only silicone is applied to the sealing material.

Accordingly, the present invention provides a method for producing the following solar cell module.
[ 1 ]
A light transmitting substrate or a light transmitting film is provided on the light receiving surface side, and a light transmitting substrate or a light transmitting film or a back surface protective material is provided on the back surface, and the light transmitting substrate or the light transmission film is provided on the back surface. Or the manufacturing method of the solar cell module by which the silicone layer is formed in the outer surface of back surface protection material, Comprising:
The silicone layer is
(A) The following average composition formula (I)
R ¹ _a SiO _{(4-a) / 2} (I)
(Wherein, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05).
100 parts by mass of an organopolysiloxane having a degree of polymerization of 100 or more,
(B) 20 to 150 parts by mass of a reinforcing silica having a specific surface area of 50 m ² / g or more,
(C) A combination of an organohydrogenpolysiloxane (crosslinking agent) as a curing agent and a hydrosilylation reaction catalyst An effective amount to cure the component (A)
A silicone composition comprising
A sheet-like silicone composition unvulcanized, forming a rear surface side light-transmitting substrate or the back side light-transmitting film or the back surface protection member and a pre-contact is allowed structure,
A light receiving surface side light-transmitting substrate or the light-receiving surface side light-transmitting film, and a solar cell element strings, Ru are stacked and the sealing material, and said structure step,
The resulting laminate is heated and pressed under vacuum using a vacuum laminator to cure the unvulcanized silicone composition, and the outer surface of the back side light transmitting substrate or back side light transmitting film or back surface protective material step of sealing at the same time to form a silicone layer, a solar cell element string in a sealing material
A manufacturing method of a solar cell module characterized by including .
[ 2 ]
A light transmitting substrate or a light transmitting film is provided on the light receiving surface side, and a light transmitting substrate or a light transmitting film or a back surface protective material is provided on the back surface, and the light transmitting substrate or the light transmission film is provided on the back surface. Or the manufacturing method of the solar cell module by which the silicone layer is formed in the outer surface of back surface protection material, Comprising:
The silicone layer is
(A) The following average composition formula (I)
R ¹ _a SiO _{(4-a) / 2} (I)
(Wherein, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05).
100 parts by mass of an organopolysiloxane having a degree of polymerization of 100 or more,
(B) 20 to 150 parts by mass of a reinforcing silica having a specific surface area of 50 m ² / g or more,
(C) A combination of an organohydrogenpolysiloxane (crosslinking agent) as a curing agent and a hydrosilylation reaction catalyst An effective amount to cure the component (A)
A silicone composition comprising
A solar cell in which a solar cell element string is sealed between a light receiving surface side light transmitting substrate or light receiving surface side light transmitting film and a back surface side light transmitting substrate or a back surface side light transmitting film or a back surface protective material Laminating a layer of an unvulcanized sheet-like silicone composition on the outer surface of the back side light transmitting substrate or the back side light transmitting film or the back surface protective material of the module;
Forming a silicone layer by heat curing the silicone composition using a heating plate
A manufacturing method of a solar cell module characterized by including .
[ 3 ]
Furthermore, the method for producing a solar cell module according to [1] or [2], wherein the silicone composition further comprises (D) a flame retardant.
[ 4 ]
The thickness of a silicone layer is 0.05-3 mm, The manufacturing method of the solar cell module in any one of [1] -[3] characterized by the above-mentioned.

  INDUSTRIAL APPLICABILITY The solar cell module of the present invention can provide a solar cell module which is not significantly changed as the solar cell module structure, has improved flame retardancy, and is compatible with the spark test and the like. Further, in the present invention, by post-installing silicone on the solar cell module which has already been formed, the flame retardancy can be improved, and a feature suitable for the spark test and the like can be added.

  The solar cell module of the present invention provides a solar cell module process which can be easily manufactured using a vacuum laminator without any significant change in the process of manufacturing the solar cell module, has improved flame retardancy, and is compatible with spark tests and the like. It is something that can be done.

It is sectional drawing of the solar cell module which concerns on the 1st Example of this invention. It is sectional drawing of the solar cell module which concerns on the 2nd Example of this invention. FIG. 6 is a cross-sectional view of a solar cell module of Comparative Example 1;

  The solar cell module according to the present invention is a solar cell module having a light transmitting substrate or a light transmitting film on the light receiving surface side, and a crystalline solar cell element or a thin film solar cell element comprising a semiconductor substrate as a power generation element is disposed. The present invention is applicable to a solar cell module provided with a light transmitting substrate or a light transmitting film or a back surface protection material on the back side, and exerts an effect in all.

  A white sheet glass, a polycarbonate, an acrylic resin board etc. are used as a transparent substrate of the light-receiving surface side of the solar cell module which concerns on this invention, A fluorine resin etc., such as ETFE, are used as a transparent film.

  As the sealing material of the solar cell module according to the present invention, a sealing material such as EVA, polyolefin, ionomer, etc. can be used, and a structure in which silicone is at least partially composite-laminated to these sealing materials is used. It can also be used. In addition, you may use silicone alone.

  In the present invention, the silicone layer is laminated on the outer surface of the light transmitting substrate or the light transmitting film or the back surface protective material used on the back surface side of the solar cell module.

  The light transmitting substrate and the light transmitting film on the back side according to the present invention are the same as the light transmitting substrate and the film on the light receiving surface side. As a back surface protection material, TPT "PVF (polyvinyl fluoride) / adhesive / PET (polyethylene terephthalate) / adhesive / PVF", TPE "PVF / adhesive / PET / adhesive / EVA", or especially "PVF" The film of the laminate shown in “adhesive / PET” or the like is used.

  In this case, the present invention can impart a flame retardant effect by forming a flame retardant silicone layer on the outer surface of the light transmitting substrate or the light transmitting film on the back surface side or the back surface protective material.

  The silicone layer according to the present invention is preferably in the form of a sheet, and can be processed with a uniform film thickness.

  With regard to the flame retardant silicone layer, since the light transmittance is inferior, it is possible to apply a structure that does not require light transmittance on the back side of the solar cell module. When light transmittance is required on the back side of the solar cell module, a light-transmissive silicone layer to which a flame retardant material is not applied can be applied.

  FIG. 1: shows an example of the silicone layer arrangement | positioning aspect of a solar cell module. FIG. 1 shows a solar cell module 100 according to a first embodiment of the present invention, which is an example of white sheet glass, a sealing material EVA layer 102, and a solar cell element as a light receiving surface side light transmitting substrate 101 from the sunlight incident direction. A crystalline silicon solar cell element string 103, a sealing material EVA layer 102, a back surface side light transmitting substrate or a light transmitting film or a back surface protecting material 104, and a silicone layer 105 are formed in this order. These laminates are heated and pressed under vacuum by a vacuum laminator, crosslinked and integrated. Although the solar cell module 100 formed in this manner is not shown, the outer peripheral portion is surrounded by an aluminum frame, and a terminal box for taking out the electrodes is attached to the back side to become a completed type.

  Further, FIG. 2 shows a solar cell module 200 according to the second embodiment of the present invention, wherein white sheet glass, a sealing material EVA layer 102, crystalline silicon solar cell element strings as a light transmitting substrate 101 from the sunlight incident direction. 103, a sealing material EVA layer 102, a back light transmitting substrate or light transmitting film or back protection material 104, and a silicone layer (flame retardant silicone layer) 106 containing a flame retardancy imparting material There is.

  Moreover, FIG. 3 is a solar cell module 300 which is a comparative example of the present invention, showing white sheet glass as a light transmitting substrate 101, a sealing material EVA layer 102, crystalline silicon solar cell element strings 103, and sealing It is comprised in order of the stop material EVA layer 102, a back surface side transparent board | substrate or a transparent film, or the back surface protection material 104. As shown in FIG.

  Here, the thickness of the silicone layer to be used is preferably 0.05 to 3 mm, particularly 0.1 to 1 mm. The thickness of the silicone layer to which the flame retardant is imparted is likewise preferably 0.05 to 3 mm, particularly 0.1 to 1 mm. In order to obtain the feature of flame retardancy, the thickness of the silicone layer is preferably large, but there is a problem that the cost increases.

In the present invention, the silicone layer is preferably obtained by curing a silicone composition containing the following components (A) to (C).
(A) The following average composition formula (I)
R ¹ _a SiO _{(4-a) / 2} (I)
(Wherein, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05).
Organopolysiloxanes having a degree of polymerization of 100 or more,
(B) Reinforcing silica having a specific surface area of 50 m ² / g or more,
(C) Curing agent Effective amount to cure the component (A).
In this case, for the purpose of imparting flame retardancy, (D) a flame retarder can be blended.

More specifically, the component (A) is an organopolysiloxane having a degree of polymerization of 100 or more, which is represented by the following average composition formula (I).
R ¹ _a SiO _{(4-a) / 2} (I)
(Wherein, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05).

In the above average composition formula (I), R ¹ represents the same or different non-substituted or substituted monovalent hydrocarbon group, and usually has 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, And alkyl groups such as methyl, ethyl, propyl, butyl, hexyl and octyl, cycloalkyl groups such as cyclopentyl and cyclohexyl, alkenyl groups such as vinyl, allyl and propenyl, and cyclo An alkenyl group, an aryl group such as a phenyl group or a tolyl group, an aralkyl group such as a benzyl group or a 2-phenylethyl group, or a group obtained by substituting part or all of the hydrogen atoms of these groups with a halogen atom or a cyano group Among these, methyl, vinyl, phenyl and trifluoropropyl are preferable, and methyl and vinyl are particularly preferable.

  Specifically, the main chain of the organopolysiloxane comprises repeating dimethylsiloxane units, or part of the dimethylpolysiloxane structure consisting of repeating dimethylsiloxane units constituting the main chain, a phenyl group, a vinyl group, It is preferable to use a diphenylsiloxane unit having a 3,3,3-trifluoropropyl group or the like, a methylphenylsiloxane unit, a methylvinylsiloxane unit, a methyl-3,3,3-trifluoropropylsiloxane unit or the like, and the like. .

In particular, those having an aliphatic unsaturated group such as two or more of an alkenyl group and a cycloalkenyl group in one molecule of organopolysiloxane are preferable, and a vinyl group is particularly preferable. In this case, it is preferable that 0.01 to 20% by mole, particularly 0.02 to 10% by mole of all R ¹ is an aliphatic unsaturated group. The aliphatic unsaturated group may be bonded to the silicon atom at the molecular chain end, or may be bonded to the silicon atom in the middle of the molecular chain, or both, but at least the molecular chain terminal Preferably, it is bonded to the silicon atom of In addition, a is a positive number of 1.95 to 2.05, preferably 1.98 to 2.02, and more preferably 1.99 to 2.01.

  The organopolysiloxane of component (A) is blocked at the molecular chain end with a triorganosiloxy group such as a trimethylsiloxy group, dimethylphenylsiloxy group, dimethylhydroxysiloxy group, dimethylvinylsiloxy group, methyldivinylsiloxy group, trivinylsiloxy group, etc. Preferred ones are listed. Particularly preferable examples include methylvinylpolysiloxane, methylphenylvinylpolysiloxane, methyltrifluoropropylvinylpolysiloxane and the like.

  Such organopolysiloxanes are obtained, for example, by (co) hydrolytic condensation of one or more of organohalogenosilanes, or alkaline or acidity of cyclic polysiloxanes (trimer, tetramer of siloxane, etc.) It can be obtained by ring-opening polymerization using a catalyst of These are basically linear diorganopolysiloxanes, but the component (A) may be a mixture of two or more different molecular weights (degree of polymerization) and molecular structures.

  The degree of polymerization of the organopolysiloxane is 100 or more, preferably 100 to 100,000, and particularly preferably 3,000 to 20,000. In addition, this polymerization degree can be measured as a weight average polymerization degree of polystyrene conversion by gel permeation chromatography (GPC) analysis.

The reinforcing silica having a BET specific surface area of 50 m ² / g or more of the component (B) is added to obtain a composition having excellent mechanical strength before and after curing. In this case, in order to improve the transparency of the silicone sealing material, the BET specific surface area is preferably more than 200 m ² / g, and more preferably 250 m ² / g or more. When the BET specific surface area is 200 m ² / g or more, the transparency of the cured product tends to be high. The upper limit is not particularly limited, but is usually 500 m ² / g or less.

  Examples of such reinforcing silica as the component (B) include fumed silica (dry silica or fumed silica), precipitated silica (wet silica) and the like. In addition, those obtained by hydrophobizing these surfaces with chlorosilane, alkoxysilane, hexamethyldisilazane or the like are also suitably used. In particular, treatment with hexamethyldisilazane is preferred because the transparency is increased. The use of fumed silica as reinforcing silica is preferred to enhance transparency. The reinforcing silica may be used alone or in combination of two or more.

  As the reinforcing silica of component (B), commercially available products can be used. For example, Aerosil series such as Aerosil 130, Aerosil 200, Aerosil 300, Aerosil R-812, Aerosil R-972, Aerosil R-974 (Japan Surface-untreated or surface-hydrophobicized with Aerosil Co., Ltd., Cabosil MS-5, MS-7 (Cabot Co., Ltd.), Leorosil QS-102, 103, MT-10 (manufactured by Tokuyama Co., Ltd.), etc. Surface-untreated or surface of (that is, hydrophilic or hydrophobic) fumed silica, Toxeal US-F (manufactured by Tokuyama Co., Ltd.), NIPSIL-SS, NIPSIL-LP (manufactured by Nippon Silica Kogyo Co., Ltd.), etc. Hydrophobicized precipitated silica and the like can be mentioned.

  The compounding amount of the reinforcing silica of the component (B) is 20 to 150 parts by mass, preferably 30 to 90 parts by mass, more preferably 50 to 50 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). 90 parts by mass. If the blending amount of the component (B) is 20 parts by mass or more, the reinforcing effect before and after curing is easily obtained, and the transparency of the silicone sealing material after curing does not decrease. When it is 150 parts by mass or less, the dispersion of the silica in the silicone sealing material is good, and at the same time, the processability to a sheet form is also good. However, when the component (D) is contained, the lower limit of the component (B) may be 5 parts by mass.

  The curing agent for the component (C) is not particularly limited as long as it can cure the component (A), but it is widely known as an addition reaction (hydrosilylation reaction) curing agent known as a curing agent for silicone compositions. That is, a combination of an organohydrogenpolysiloxane (crosslinking agent) and a hydrosilylation reaction catalyst, or (b) an organic peroxide is preferred.

The organohydrogenpolysiloxane as a crosslinking agent in the (a) addition reaction (hydrosilylation reaction) contains hydrogen atoms (SiH groups) bonded to at least two silicon atoms in one molecule, and the following averages Composition formula (II)
R ² _b H _c SiO _{(4-bc) / 2} (II)
(Wherein R ² is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, preferably one having no aliphatic unsaturated bond. Specific examples include a methyl group, an ethyl group, Alkyl group such as propyl group, butyl group, pentyl group and hexyl group, unsubstituted monovalent hydrocarbon group such as cyclohexyl group, cyclohexenyl group and phenyl group, 3,3,3-trifluoropropyl group, cyanomethyl group and the like Or a substituted monovalent hydrocarbon group such as a substituted alkyl group in which at least a part of the hydrogen atoms of the above monovalent hydrocarbon group is substituted with a halogen atom or a cyano group, b is 0.7 to 2.1, c Is 0.01 to 1.0, and b + c is 0.8 to 3.0, preferably b is 0.8 to 2.0, c is 0.2 to 1.0, and b + c is 1.0 to 2 Is a positive number satisfying .5)
The conventionally known organohydrogenpolysiloxanes shown by the above are applicable. The molecular structure of the organohydrogenpolysiloxane may be linear, cyclic, branched, or three-dimensional network. In this case, one having a number (or degree of polymerization) of silicon atoms in one molecule of 2 to 300, particularly 4 to 200, which is liquid at room temperature is preferably used. The hydrogen atom (SiH group) bonded to the silicon atom may be at the end of the molecular chain or at the side chain, or both, and at least two (usually 2 to 300) in one molecule. Preferably, those containing 3 or more (for example, 3 to 200), and more preferably 4 to 150 or so are used.

Specifically as this organohydrogenpolysiloxane, 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methyl hydrogen cyclopolysiloxane, methyl hydrogen Siloxane · dimethyl siloxane cyclic copolymer, tris (dimethylhydrogensiloxy) methylsilane, tris (dimethylhydrogensiloxy) phenylsilane, both terminal trimethylsiloxy group blocked methyl hydrogen polysiloxane, both terminal trimethylsiloxy group blocked dimethyl siloxane · methyl Hydrogen siloxane copolymer, dimethylpolysiloxane terminated with dimethylpolysiloxane, dimethylpolysiloxane terminated with dimethylsiloxane, methyl hydride Gensiloxane copolymer, both terminal trimethylsiloxy group-capped methylhydrogensiloxane diphenylsiloxane copolymer, both terminal trimethylsiloxy group-capped methylhydrogensiloxane diphenylsiloxane dimethylsiloxane copolymer, cyclic methyl hydrogen polysiloxane, Cyclic methyl hydrogen siloxane / dimethylsiloxane copolymer, cyclic methyl hydrogen siloxane / diphenylsiloxane / dimethyl siloxane copolymer, copolymer comprising (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/2 units, A copolymer or the like comprising (CH ₃ ) ₂ HSiO _1/2 units, SiO _4/2 units and (C ₆ H ₅ ) SiO _3/2 units, or in each of the above exemplified compounds, a part or all of methyl groups Other alkyl groups such as ethyl and propyl and Those substituted with an aryl group such as a phenyl group may, for example, be mentioned.

  The compounding amount of the organohydrogenpolysiloxane is 0.1 to 30 parts by mass, more preferably 0.1 to 10 parts by mass, still more preferably 0.3 with respect to 100 parts by mass of the organopolysiloxane (A). It is preferable to set it as -10 mass parts.

  In addition, this organohydrogenpolysiloxane has a molar ratio of 0.5 hydrogen atom (i.e., SiH group) bonded to the silicon atom in the component (C) to the alkenyl group bonded to the silicon atom in the component (A). It is preferable to blend in an amount of 5 to 5 mol / mol, preferably 0.8 to 4 mol / mol, more preferably 1 to 3 mol / mol.

  In addition, as the hydrosilylation reaction catalyst used for the crosslinking reaction of the above (a) addition reaction (hydrosilylation reaction), known catalysts can be applied. For example, platinum black, platinum chloride, platinum platinum chloride, platinum chloride Examples thereof include a reactant of an acid and a monohydric alcohol, a complex of chloroplatinic acid and an olefin, a platinum-based catalyst such as platinum bisacetoacetate, a palladium-based catalyst, a rhodium-based catalyst and the like. In addition, the compounding quantity of this hydrosilylation reaction catalyst can be made into a catalytic quantity, Usually, it converts into platinum group metal mass, and it is with respect to the total mass of (A), (B) component and organohydrogenpolysiloxane, 1 to 1,000 ppm is preferable, and a range of 5 to 100 ppm is more preferable. If it is less than 1 ppm, the addition reaction may not proceed sufficiently and curing may be insufficient, and it is uneconomical to add an amount exceeding 1,000 ppm.

  In addition to the above reaction catalyst, an addition reaction control agent may be used for the purpose of adjusting the curing rate or pot life. Specific examples thereof include ethynyl cyclohexanol and tetramethyl tetravinyl cyclotetrasiloxane.

  On the other hand, as the organic peroxide (b), for example, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dicumyl peroxide, 2,5-Dimethyl-bis (2,5-t-butylperoxy) hexane, di-t-butylperoxide, t-butylperbenzoate, 1,6-hexanediol-bis-t-butylperoxycarbonate etc Can be mentioned.

  The amount of the (b) organic peroxide added is preferably 0.1 to 15 parts by mass, and more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the component (A). If the addition amount is 0.1 parts by mass or more, the crosslinking reaction proceeds sufficiently to hardly cause a decrease in hardness or insufficient strength. A content of 15 parts by mass or less is preferable in terms of cost, and a large amount of decomposition products of the curing agent is generated. It is difficult to increase the color change of the sheet.

As the flame retardancy imparting agent of the component (D), known materials can be used, and platinum compounds, carbon black, fumed titanium oxide, benzara (Fe ₂ O and Fe ₃ O ₄ ), and triazoles such as benzotriazole Compounds can be formulated. The flame retardant may be used alone or in combination of two or more. The flame retardancy can also be improved by highly filling the crystalline silica or the aluminum oxide powder to relatively reduce the amount of the siloxane component.

  Although the addition amount of the component (D) is not particularly limited, it is preferably 0.001 to 0.5 parts by mass, more preferably 0.002 to 0.05 parts by mass with respect to a total of 100 parts by mass of the components (A) to (C). It is preferable to use a part.

  The silicone composition according to the present invention can be obtained by kneading a predetermined amount of the above-mentioned components with a two-roll mill, a kneader, a Banbury mixer or the like.

  The plasticity of the thus prepared silicone composition before curing will be 150 to 1,000, preferably 200 to 800, and more preferably 250 to 600. When the plasticity is greater than 150, the shape of the uncured sheet is easy to maintain, and the tack is not too strong and easy to use. In addition, if it is 1,000 or less, the sheeting process becomes easy. The degree of plasticity can be measured in accordance with JIS K6249.

  When the silicone composition in an unvulcanized state according to the present invention is formed into a sheet, the forming method is not particularly limited, but extrusion molding, calendar molding, etc. may be used. At this time, the thickness of the silicone composition sheet is preferably 0.05 to 3 mm, particularly 0.1 to 1 mm.

  The silicone composition in an unvulcanized state according to the present invention has, for example, a back surface protective material or a back surface light transmitting substrate or film as a substrate, and one surface of the silicone composition and the back surface protecting material or a back surface light transmitting substrate or film It can be molded while bonding together.

  For example, as a method of laminating a silicone composition in an unvulcanized state and a back surface protective material or a back surface light transmitting substrate or film, a sheet laminated together in advance may be simultaneously press molded with a roll or After pressing and forming, there is a method of sticking and forming while laminating simultaneously with the back surface protective material or the back surface light transmitting substrate or film in the winding process.

  In addition, hardening of the said silicone composition can be performed by heating for 20 to 60 minutes at 120-150 degreeC.

  Here, the manufacturing method of the solar cell module of the present invention will be described. For example, when the solar cell module is a solar cell module having a back side light transmitting substrate or film or a back surface protective material on the back side, The silicone composition in the state and the back side light transmitting substrate or the film or the back surface protective material are pressed in advance by a roll and attached. Others are the same as a general solar cell module formation process, the sealing material EVA is placed on the light transmitting substrate or film on the light receiving surface side, and the solar cell element strings are placed on the top, and the solar cell element strings The sealing material EVA is placed on the back surface, and the unvulcanized silicone composition and the back surface light transmitting substrate or the sheet having the film or the back surface protective material attached thereto are the back surface light transmitting substrate or film or the back surface. The protective material is placed so that it is oriented on the side of the solar cell element strings, and heating and pressing is performed under vacuum using a vacuum laminator to crosslink the silicone composition in an unvulcanized state and at the same time the solar cell element strings are sealed with a sealant. A closed solar cell module can be formed. At this time, a Teflon (registered trademark) -impregnated glass cloth may be placed on the silicone composition and used so that the silicone composition does not adhere to the rubber portion of the vacuum laminator.

  Next, a method of placing and installing the silicone composition on a solar cell module which has already been formed will be described. For example, in the case of a solar cell module having a light transmitting substrate or film on the light receiving surface side and a back surface side light transmitting substrate or film on the back surface side or a back surface protective material, only the protective film of the silicone composition is peeled off After the silicone composition is stuck on the side light transmitting substrate or film or back surface protective material, it is pressed from the upper surface of the protective film and brought into close contact using a roller or the like. The protective film is then peeled off and heated on a heating plate. At that time, heating is performed at 80 ° C. or lower for temporary pressure bonding so that the sealing material does not flow out, and thereafter heating is performed at 80 ° C. or lower in an oven.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In addition, the part of the unit of a compounding quantity is a mass part. Moreover, a weight average molecular weight and a weight average polymerization degree are polystyrene conversion values in a gel permeation chromatography (GPC) analysis.

[Example]
First, the silicone composition used in the examples will be described.
<Preparation of Translucent Silicone Composition>
100 parts of organopolysiloxane consisting of 99.85 mol% of dimethylsiloxane units, 0.025 mol% of methyl vinyl siloxane units, 0.125 mol% of dimethyl vinyl siloxane units and having an average degree of polymerization of about 6,000, BET specific surface area 70 parts of 300 m ² / g silica (trade name Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.), 16 parts of hexamethyldisilazane as a dispersant, and 4 parts of water are added and kneaded in a kneader at 170 ° C. The compound was prepared by heat treatment for 2 hours.

  100 parts of the above-mentioned compound and 0.5 parts of C-25A (platinum catalyst) / C-25B (organohydrogenpolysiloxane) (both manufactured by Shin-Etsu Chemical Co., Ltd.) as an addition crosslinking curing agent After uniformly mixing 0 parts with 2 rolls, a sheet of the silicone composition in an unvulcanized state was produced by a calender roll.

Preparation of Flame Retardant Silicone Composition
100 parts of organopolysiloxane consisting of 99.85 mol% of dimethylsiloxane units, 0.025 mol% of methyl vinyl siloxane units, 0.125 mol% of dimethyl vinyl siloxane units and having an average degree of polymerization of about 6,000, BET specific surface area 30 parts of 200 m ² / g of silica (trade name Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.), 4 parts of hexamethyldisilazane as a dispersant, and 1.2 parts of water are added and kneaded in a kneader, 170 ° C. The mixture was heat treated for 2 hours to prepare a compound.

  100 parts by mass of the above compound 50 parts by mass of crystalline silica (Crystallite VX-S Co., Ltd. Ryumori) having an average particle diameter of 4 μm and titanium oxide CR-60 having an average particle diameter of 0.2 μm (Ishihara Sangyo Co., Ltd.) 3 parts by mass and 0.015 parts by mass of benzotriazole to obtain a flame retardant silicone compound.

  This compound is added in an amount of 0.5 parts of C-25A (platinum catalyst) / C-25B (organohydrogenpolysiloxane) (both from Shin-Etsu Chemical Co., Ltd.) as an addition crosslinking curing agent. After uniformly mixing 0 parts with 2 rolls, a sheet of the silicone composition in an unvulcanized state was produced by a calender roll. If necessary, protective sheets were laminated on both sides of this sheet.

  In addition, EVA sheet (fast cure type) for SANBIC Co., Ltd. solar cell is used as EVA, Nakajima Glass Industrial Co., Ltd. white sheet glass (3.2 mm thickness, with single-sided embossed shape) as a light transmitting substrate on the surface, back surface protection material The solar cell module of the Example and the comparative example was produced using TPT (Tedlar-PET-Tedlar: PTD250) of MA packaging Co., Ltd. as a.

  The solar cell module 100 (FIG. 1) shown in the example prepares a sheet in which a sheet of an unvulcanized silicone composition is previously bonded to the back surface protective material TPT 104, and a white sheet glass 101, a sealing material EVA layer 102, a solar cell The element strings 103, the sealing material EVA layer 102, and the bonded sheet were laminated, and heat compression bonding was performed using a vacuum heating laminator. The thickness of silicone is 0.5 mm.

  The solar cell module 200 (FIG. 2) shown in the example prepares a sheet in which the sheet of the unvulcanized silicone composition to which the flame retardant material has been applied is bonded in advance to the back surface protective material TPT104. The EVA layer 102, the solar cell element strings 103, the sealing material EVA layer 102, and the bonded sheet were laminated, and heat compression bonding was performed using a vacuum heating laminator. Moreover, the thickness of the silicone which gave the flame retardant is 0.5 mm.

  The solar cell module 300 (FIG. 3) shown in the comparative example does not attach the unvulcanized silicone composition, and the sealing material EVA layer 102, the solar cell element strings 103, and the sealing material EVA layer are formed on the white sheet glass 101. 102, a back surface protective material TPT104 is laminated, and heat compression bonding is performed by vacuum lamination at 140 ° C. for 5 minutes under vacuum and vacuum pressure bonding for 25 minutes.

Next, each process in manufacture of each solar cell module is demonstrated.
[Fabrication of solar cell module]
[1] Preparation of Unvulcanized Silicone and Adhesion to Back Surface Protective Material The above silicone composition was formed into a sheet by calendering. At this time, the sheet thickness of the silicone composition in an unvulcanized state is prepared to be 0.03 mm, 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 3 mm thick, and the back surface protective material TPT104 is used as a substrate. It was processed while being attached.
The upper surface of the silicone composition in the uncured state was formed by pressing the embossed film to protect the silicone surface.
[2] Configuration of Solar Cell Element (Cell) As a solar cell, a 156 mm square p-type single crystal cell for a solar cell was used.
[3] Production of Solar Cell Element (Cell) Strings The solar cell cell strings 103 were arranged in 60 straight sizes (6 × 10 columns), and connection wires were respectively connected in series and formed.
[4] Formation of Solar Cell Module The solar cell module 100 will be described as an example.
The sealing material EVA 102 was placed on the upper surface of the white sheet glass 101. The solar cell strings 103 are placed on the top surface of the EVA 102, the EVA 102 is placed on the top surface, and the back protective material TPT seals the laminate sheet on which the final unvulcanized silicone composition and the back protective material TPT 104 are attached. It mounted in the form orientated to stop material EVA102.
The laminate thus obtained was vacuum heated and pressed for 30 minutes at 140 ° C. under a vacuum of 5 minutes and vacuum pressure bonding for 30 minutes with a vacuum laminator to form a solar cell module. At this time, a Teflon (registered trademark) impregnated cross sheet was used on the upper surface of the silicone sheet so that the pressing surface of the vacuum laminator would not stick to the silicone sheet.

  In the solar cell module manufactured through the above steps, a frame made of aluminum alloy was attached to the periphery, an edge seal material such as silicone was enclosed, and the final frame corner was screwed to complete the final solar cell module .

  Next, a method of forming a solar cell module in which a silicone composition is placed on a solar cell module which has already been formed will be described.

  A sheet of the silicone composition with a thickness of 0.5 mm on the back surface protective material TPT104 of the solar cell module (crystal system) which has already been formed, and with the protective sheet peeled off on only one side, the peeled surface is oriented to TPT. After pasting and pressing with a roller, the protective sheet on the other side of the silicone composition was peeled off. Thereafter, the solar cell module was placed on a heating plate at 80 ° C. with the glass surface oriented to the heating plate and heated for 40 minutes. After heating, it was heated in an atmosphere at 70 ° C. for 2 hours in an air atmosphere.

Next, an example and a comparative example of a spark test are shown.
[Spring test]
Implemented in accordance with Article 63 of the Building Standard Act.
The brand prepared two wooden brands having a size of 80 mm × 80 mm × 60 mm and a weight of 155 g per specimen, and was precured for 24 hours or more at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%.
As for the blowing, the outlet height was 250 mm, the width was 1,000 mm or more, and the length of the blowout nozzle was 1,200 mm or more.
The burner temperature was set to be 900 ± 50 ° C. at 60 mm from the top of the burner, and the brand was exposed to the flame for 240 seconds.
The solar cell module produced as described above was placed at an inclination angle of 30 ° so that the light receiving surface side glass was on the top.
Two brands were placed on the top of the solar cell module as specified in Article 63 of the Building Standard Law. The test was continued until the burning of the brand completely disappeared, and the condition of the solar cell module after burning was observed.

First, Table 1 shows the results of the spark test of the solar cell module in which the silicone composition was formed to a thickness of 0.5 mm.

Next, the result of a spark test of a solar cell module to which a silicone composition is not attached, which is a comparative example, is shown in Table 2.

As shown in Table 1, all the solar cell modules in Table 1 passed with no combustion through holes in the state of the solar cell modules after the spark test. In particular, the solar cell module 200 using the flame retardant silicone had a small burn area on the back of the solar cell module and a high flame retardancy.
As shown in Table 2, in the state of the solar cell module after the spark test, in the solar cell module 300, a combustion through hole was generated, and the brand fell on the back side. The through hole was 200 × 200 mm and was rejected.

  Moreover, in the solar cell module 100, the evaluation result in which the thickness of silicone was changed is shown in Table 3.

As shown in Table 3, when the thickness of the silicone layer was 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, and 3 mm, the combustion through holes were not generated and the test was passed.
Further, in any of the pass determinations, no combustion accompanied by a flame was found on the back of the solar cell module.
Furthermore, the tip of the flame by combustion of the test body did not reach the position of 600 mm on the left and right.

  On the other hand, as shown in Table 4, when the thickness of the silicone layer was 0.03 mm, in the spark test, the combustion through holes were 120 x 120 mm and part of the brand dropped on the back surface, which resulted in rejection. Therefore, the thickness of the silicone layer is preferably 0.05 mm or more.

  Subsequently, the results of the spark test of the solar cell module which has already been formed and the solar cell module in which the silicone layer is placed on the module are shown in Table 5.

  As described above, the solar cell module according to the present invention can enhance flame retardancy by installing silicone on the back surface light transmitting substrate, the back surface light transmitting film, and the back surface protective material, and is suitable for the spark test. It is possible to provide a solar cell module that

100, 200, 300 solar cell module 101 light transmitting substrate 102 sealing material EVA layer 103 solar cell strings 104 back surface protective material 105 silicone layer 106 flame retardant imparting silicone layer

Claims (4)

A light transmitting substrate or a light transmitting film is provided on the light receiving surface side, and a light transmitting substrate or a light transmitting film or a back surface protective material is provided on the back surface, and the light transmitting substrate or the light transmission film is provided on the back surface. Or the manufacturing method of the solar cell module by which the silicone layer is formed in the outer surface of back surface protection material, Comprising:
The silicone layer is
(A) The following average composition formula (I)
R ¹ _a SiO _{(4-a) / 2} (I)
(Wherein, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05).
100 parts by mass of an organopolysiloxane having a degree of polymerization of 100 or more,
(B) 20 to 150 parts by mass of a reinforcing silica having a specific surface area of 50 m ² / g or more,
(C) A combination of an organohydrogenpolysiloxane (crosslinking agent) as a curing agent and a hydrosilylation reaction catalyst An effective amount to cure the component (A)
A silicone composition comprising
A sheet-like silicone composition unvulcanized, forming a rear surface side light-transmitting substrate or the back side light-transmitting film or the back surface protection member and a pre-contact is allowed structure,
A light receiving surface side light-transmitting substrate or the light-receiving surface side light-transmitting film, and a solar cell element strings, Ru are stacked and the sealing material, and said structure step,
The resulting laminate is heated and pressed under vacuum using a vacuum laminator to cure the unvulcanized silicone composition, and the outer surface of the back side light transmitting substrate or back side light transmitting film or back surface protective material step of sealing at the same time to form a silicone layer, a solar cell element string in a sealing material
A manufacturing method of a solar cell module characterized by including . A light transmitting substrate or a light transmitting film is provided on the light receiving surface side, and a light transmitting substrate or a light transmitting film or a back surface protective material is provided on the back surface, and the light transmitting substrate or the light transmission film is provided on the back surface. Or the manufacturing method of the solar cell module by which the silicone layer is formed in the outer surface of back surface protection material, Comprising:
The silicone layer is
(A) The following average composition formula (I)
R ¹ _a SiO _{(4-a) / 2} (I)
(Wherein, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05).
100 parts by mass of an organopolysiloxane having a degree of polymerization of 100 or more,
(B) 20 to 150 parts by mass of a reinforcing silica having a specific surface area of 50 m ² / g or more,
(C) A combination of an organohydrogenpolysiloxane (crosslinking agent) as a curing agent and a hydrosilylation reaction catalyst An effective amount to cure the component (A)
A silicone composition comprising
A solar cell in which a solar cell element string is sealed between a light receiving surface side light transmitting substrate or light receiving surface side light transmitting film and a back surface side light transmitting substrate or a back surface side light transmitting film or a back surface protective material Laminating a layer of an unvulcanized sheet-like silicone composition on the outer surface of the back side light transmitting substrate or the back side light transmitting film or the back surface protective material of the module;
Forming a silicone layer by heat curing the silicone composition using a heating plate
A manufacturing method of a solar cell module characterized by including . The method for producing a solar cell module according to claim 1 or 2, further comprising (D) a flame retardancy imparting agent in the silicone composition. The thickness of a silicone layer is 0.05-3 mm, The manufacturing method of the solar cell module in any one of the Claims 1-3 characterized by the above-mentioned.

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