JP2014099514A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a see-through and light-through solar cell module which, although inexpensive materials are used, can simply adjust its daylighting properties and excels in reliability because of its high interlayer adhesion.SOLUTION: A solar cell module of the present invention is a see-through and light-through solar cell module including, from a light incident side, a weatherproof protective member, a plurality of solar cell elements, and a solar cell back sheet. The solar cell back sheet is a hot-melt resin composition containing 100 pts.wt. of polyolefin hot-melt resin which includes at least two plastic films for holding an adhesive layer therebetween, the material of the adhesive layer being modified with a polar vinyl compound, and 0.0001-20 pts.wt. of one or more kinds of coloring agent selected from the group consisting of a pigment and a dye.

Description

  The present invention relates to a laminate using an epoxy-modified polyolefin resin composition, a solar cell backsheet, and a method for producing the same.

  In recent years, attention has been focused on solar cells that directly convert sunlight into electric energy from the viewpoint of effective use of resources and prevention of environmental pollution. The solar cell has, as basic elements, a power generation element, a sealing material, a back surface protective film (back sheet), and a transparent light receiving plate (glass plate or the like) provided on the light receiving side of the power generation element.

  Today, various types of solar cells such as see-through type, light-through type, flexible type, and roof tile-integrated type have been developed, and it can be said that solar cells are diversified. With the diversification of solar cells, the performance required for peripheral materials is diversifying, and the development of highly functional peripheral materials is required.

  For example, Patent Document 1 discloses a transparent protective sheet that is suitably used for a see-through type solar cell module, and includes a first resin sheet, a first protective sheet for the solar cell module, from the surface (exposed surface) side. It is a laminate in which an adhesive layer, an ultraviolet shielding layer, a second resin sheet, a second adhesive layer, and a resin layer are laminated in order, and at least the first adhesive layer is a two-component laminate comprising a main agent and a curing agent. A layer obtained by curing the adhesive, and the main component of the laminate adhesive is a protective sheet containing a mixture of a specific polyurethane diol (A) and an aliphatic polycarbonate diol (B). It is disclosed that a transparent solar cell module in which yellowing during use is suppressed can be provided.

JP2012-0779868A

  In view of the above-mentioned background art, it is necessary to prevent yellowing in the protective member on the sunlight incident side and the constituent member of the back sheet used in the see-through type and light-through type solar cells, and the lighting property is required. Therefore, the present inventors thought that it was necessary to adjust the transmittance of the sheet.

  First, it is assumed that the cause of this yellowing is mainly due to the deterioration of the resin, which is the material of the structural member, due to ultraviolet rays due to sunlight irradiation, and the function of adjusting the transmittance of the above-described sheet Therefore, the transmittance of the protective member on the sunlight incident side is determined separately from the adjustment of the transmittance of the entire module. Was found to be adjustable to maximize.

  Here, in order to manufacture such a see-through type and a light-through type back sheet, the inventors of the present invention have a method of pasting a colored film having appropriate lighting properties with a transparent adhesive resin, and coloring the transparent film. I thought that there was a method of pasting together with the adhesive resin. Moreover, the former judged that the transmittance | permeability of the colored film to be used had to be adjusted, and the latter had the subject that it should keep the adhesive strength from falling, while coloring adhesive resin.

  In order to adjust the transmittance of the backsheet, it is preferable to use a backsheet having a multilayer structure, and it is possible to adjust the adhesive layer to an appropriate transmittance instead of the film layer which is a constituent member thereof. The present inventors have found that this is preferable from the viewpoint of manufacturing backsheets adjusted to various transmittances.

  However, in this case, an appropriate adhesive layer is selected that has appropriate lighting characteristics, that is, transmittance, and can also have characteristics required for the backsheet such as water vapor transmission rate and interlayer adhesion strength. There is a need.

  Here, if the transmittance of an inexpensive polyolefin-based hot melt adhesive can be adjusted and good adhesiveness can be maintained, an inexpensive back sheet can be produced by laminating an inexpensive transparent polyester film by an extrusion laminating method or the like. However, although thermoplastic resins based on polyolefins are used as hot-melt adhesives for plastic materials, there is a problem of insufficient adhesion to polar resins. Furthermore, when a pigment or dye is added to a polyolefin-based thermoplastic resin, the added pigment or dye bleeds, causing a problem of poor appearance or poor adhesion.

  For this reason, the present inventors have a daylighting property by coloring the hot-melt adhesive based on polyolefin, improving the adhesion to polar resins, and using it as an adhesive layer for the backsheet. Making it possible to manufacture a back sheet was set as a problem to be solved by the present invention.

  That is, the problem of the present invention is that it is possible to easily adjust the daylighting property despite the use of an inexpensive material, and it has excellent reliability due to high interlayer adhesion. It is to provide a solar cell module.

  As a result of intensive studies on the above problems, the present inventors can easily adjust the daylighting property using an inexpensive material by using a back sheet including an adhesive layer made of a specific material, and The present inventors completed the present invention by discovering that the see-through and light-through solar cell modules have excellent reliability due to high interlayer adhesion.

  That is, when the present inventors add 0.0001 to 20 parts by weight of a pigment or a dye to a polyolefin hot melt resin containing an inexpensive polar vinyl compound, the polar resin of the polyolefin hot melt resin, for example, a polyester film In addition, it was found that the daylighting property can be adjusted by adjusting the number of added parts while improving the adhesiveness to the surface, and discovered that this can be utilized as an adhesive layer for the backsheet having the daylighting property, thereby completing the present invention. I let you.

  That is, the solar cell module of the present invention is a see-through, light-through solar cell module including a weatherproof protective member, a plurality of solar cell elements, and a solar cell backsheet from the light incident side, and the solar cell backsheet is From a group consisting of 100 parts by weight of a polyolefin-based hot-melt resin, which includes at least two plastic films sandwiching the adhesive layer, and wherein the material of the adhesive layer is modified with a polar vinyl compound, a pigment, and a dye The present invention relates to a see-through and a light-through solar cell module, which is a hot-melt resin composition containing one or more selected colorants from 0.0001 to 20 parts by weight.

  The polyolefin hot melt resin is preferably further modified with an aromatic vinyl compound.

  The polar vinyl compound preferably contains an unsaturated polar group having at least one polar group selected from the group consisting of epoxy, unsaturated carboxylic acid, and unsaturated carboxylic acid anhydride.

  The polyolefin-based hot-melt resin includes (a-2) an epoxy group-containing vinyl monomer and (a-3) an aromatic vinyl in the presence of a radical polymerization initiator with respect to the polyolefin-based resin. It is preferably an epoxy-modified polyolefin hot melt resin obtained by melt-kneading a monomer.

  The polyolefin hot-melt resin is (a-1) 0.5 to 30 parts by weight of an epoxy group-containing vinyl monomer in the presence of a radical polymerization initiator with respect to 100 parts by weight of the polyolefin resin. And (a-3) an epoxy-modified polyolefin hot melt resin obtained by melt-kneading 0-30 parts by weight of an aromatic vinyl monomer.

  The colorant is preferably a carbon-based material or a dye intended to be colored black.

  The total light transmittance of the solar cell backsheet is preferably 0 to 70%.

  The plastic film is preferably a polyester film.

  The solar battery backsheet is preferably a backsheet laminated by an extrusion lamination method.

  The solar cell module of the present invention can easily adjust its daylighting property despite the use of an inexpensive material, and has high interlaminar adhesion, and is excellent in reliability. See-through and write-through It is a solar cell module.

  The present invention is described in detail below.

  The polyolefin-based hot melt resin of the present invention contains a polar vinyl compound, and is characterized by containing 100 parts by weight of a polyolefin-based hot melt resin and a pigment and / or a dye of 0.0001 to 20 parts by weight.

  Polyolefin hot melt resins include, for example, polyethylene, polypropylene, poly-1-butene, polyisobutylene, polymethylpentene, propylene-ethylene copolymer, ethylene-propylene-diene copolymer, ethylene / butene-1 copolymer. , Polyolefins such as ethylene / octene copolymers, cyclic polyolefins such as copolymers of cyclopentadiene and ethylene and / or propylene, ethylene / vinyl acetate copolymers (EVA), ethylene / ethyl acrylate copolymers (EEA) ), And polyolefins introduced with polar groups such as isobutylene / maleic anhydride copolymer, acid-modified polypropylene such as maleic anhydride-modified polypropylene, maleic acid-modified polypropylene, and acrylic acid-modified polypropylene. Among them, polyethylene, polypropylene, and propylene-ethylene copolymer are preferable, polypropylene and propylene-ethylene copolymer are more preferable, and propylene-ethylene copolymer has an ethylene content of 5 to 15% by weight. Particularly preferred.

  The polar vinyl compound is not particularly limited as long as it is derived from a raw material containing a vinyl group and a polar functional group. Unsaturated carboxylic acid, its anhydride, epoxy group-containing vinyl compound, hydroxyl group-containing vinyl compound, halogen And vinyl-containing compounds.

  Examples of the hydroxyl group-containing vinyl compound include vinyl alcohol, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, cyclohexane dimethanol monovinyl ether, and the like.

  Examples of the halogen-containing vinyl compound include vinyl chloride and vinyl fluoride.

  The modification with a polar vinyl compound means that a polar vinyl compound is added to the polyolefin resin and allowed to react, and examples thereof include copolymerization, block copolymerization, living polymerization, graft polymerization, and solution polymerization. Preferably, a polar vinyl compound is added to a mixture obtained by melting and kneading a polyolefin resin and a radical polymerization initiator, and then melt kneading. More preferably, extrusion melt kneading is preferably performed. In this case, it is preferable that the polar vinyl compound participates in the graft reaction as the reaction, and it is particularly preferable that the polar vinyl compound is grafted to the main chain of the polyolefin resin.

  As the pigment, either an inorganic pigment or an organic pigment can be used, and examples thereof include carbon black, ultramarine, amber, senna, calcium carbonate, kaolin, titanium dioxide, polycyclic pigment, azo pigment, and lake pigment.

  Examples of the dye include natural dyes, synthetic dyes, and fluorescent dyes.

  The pigment and the dye can be used alone or in admixture of two or more.

  Examples of the aromatic vinyl compound include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, β-methyl styrene, dimethyl styrene, trimethyl styrene, and other methyl styrene, o-chloro styrene, m -Chlorostyrene such as chlorostyrene, p-chlorostyrene, α-chlorostyrene, β-chlorostyrene, dichlorostyrene, trichlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, dibromostyrene, tribromostyrene Such as bromostyrene, o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, difluorostyrene, trifluorostyrene, etc., o-nitrostyrene, m-nitrostyrene, p-nitrostyrene, dinit Nitrostyrene such as styrene and trinitrostyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, dihydroxystyrene, vinylphenol such as trihydroxystyrene, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene And diisopropenylbenzene such as o-diisopropenylbenzene, m-diisopropenylbenzene, and p-diisopropenylbenzene. Among these, styrene, α-methylstyrene, p-methylstyrene, divinylbenzene monomer or divinylbenzene isomer mixture is preferable, and styrene is particularly preferable. Said aromatic vinyl monomer can be used individually or in mixture of 2 or more types.

  Epoxy is a compound containing an epoxy group, such as glycidyl methacrylate (GMA), glycidyl acrylate, monoglycidyl maleate, diglycidyl maleate, monoglycidyl itaconate, diglycidyl itaconate, monoglycidyl allyl succinate, allyl succinate Acid diglycidyl, p-styrene carboxylic acid glycidyl, allyl glycidyl ether, methacryl glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, 3,4-epoxy-1-butene, 3,4-epoxy-3-methyl- Examples include 1-butene. Among these, glycidyl methacrylate and glycidyl acrylate are preferable, and glycidyl methacrylate is particularly preferable. Said epoxy group containing compound can also be used individually or in mixture of 2 or more types.

Examples of the unsaturated carboxylic acid include maleic acid, phthalic acid, methacrylic acid, acrylic acid, vinyl acetate, and derivatives thereof.
Examples of the carboxylic acid anhydride include maleic anhydride and phthalic anhydride.

  The addition amount of the aromatic vinyl monomer is preferably 0.1 to 50 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the (a-1) polyolefin resin. . If the amount added is too small, the graft ratio of the epoxy group-containing vinyl monomer to the polyolefin resin tends to be inferior, which is not preferable. If the amount added is too large, the grafting efficiency of the epoxy group-containing vinyl monomer reaches the saturation range, so it is preferable to set the upper limit to 50 parts by weight.

  Examples of radical initiators include ketone peroxides such as methyl ethyl ketone peroxide and methyl acetoacetate peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t -Peroxyketals such as -butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, permethane hydroperoxide, Hydroperoxides such as 1,1,3,3-tetramethylbutyl hydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, α, α ' Bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 Dialkyl peroxides such as dialkyl peroxides such as benzoyl peroxide, peroxydicarbonates such as di (3-methyl-3-methoxybutyl) peroxydicarbonate, di-2-methoxybutylperoxydicarbonate, t- Butyl peroxyoctate, t-butyl peroxyisobutyrate, t-butyl peroxylaurate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxyisopropyl carbonate, 2, 5-Dimethyl-2,5-di (benzoylperoxy Hexane, t- butyl peroxy acetate, t- butyl peroxybenzoate, etc. peroxy esters such as di -t- butyl peroxy isophthalate and the like.

  Among them, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl Peroxyketals such as 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, dicumyl peroxide, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexane, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2, Dialkyl peroxides such as 5-di (t-butylperoxy) hexyne-3, diacyl peroxides such as benzoyl peroxide; t-butyl -Oxyoctate, t-butyl peroxyisobutyrate, t-butyl peroxylaurate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxyisopropyl carbonate, 2,5 It is preferable to use -dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, or the like. Said radical initiator can be used individually or in mixture of 2 or more types.

  The addition amount of the radical polymerization initiator is preferably 0.01 to 10 parts by weight and more preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the (a-1) polyolefin resin. .

  Examples of the carbon-based material include graphite, carbon black, ketjen black, graphene, carbon nanoparticles, carbon nanotubes, fullerene, diamond, acetylene black, and derivatives thereof.

As a method for adding the colorant, it is added when the resin is melt-kneaded. The timing of addition may be either before or after the modification, but it is preferable to add while modifying or after the modification.
If necessary, the epoxy-modified polyolefin resin composition of the present invention may be added with a thermoplastic resin, an elastomer, a tackifier (tackifier), a plasticizer and the like within a range not impairing the effects of the present invention. Also good.

  Examples of the elastomer include styrene thermoplastic elastomer (TPS), olefin thermoplastic elastomer (TPO), butyl rubber, acrylic rubber, chlorinated polyethylene, butadiene rubber, isoprene rubber, and styrene-butadiene rubber.

  The tackifier is a low-molecular resin having a number average molecular weight of 300 to 3000 and a softening point of 60 to 150 ° C. based on the ring and ball method defined in JISK-2207, and includes rosin and rosin derivatives, polyterpene resins, aromatics -Modified terpene resins and their hydrides, terpene phenol resins, coumarone-indene resins, aliphatic petroleum resins, alicyclic petroleum resins and their hydrides, aromatic petroleum resins and their hydrides, aliphatic aromatics Examples thereof include low molecular weight polymers of copolymer petroleum resins, dicyclopentadiene petroleum resins and their hydrides, styrene or substituted styrene.

  Examples of the plasticizer include petroleum-based process oils such as paraffinic process oil, naphthenic process oil, aromatic process oil, low molecular weight liquid polymers such as silicone oil, liquid polybutene, and liquid polyisoprene.

  Furthermore, additives such as antioxidants, ultraviolet absorbers, chain transfer agents, nucleating agents, lubricants, fillers, flame retardants, and antistatic agents are added as necessary within the range not impairing the effects of the present invention. May be.

  These additives may be added in advance to the polyolefin resin, may be added when the polyolefin resin is melted, or may be added after the epoxy-modified polyolefin resin composition is produced.

  About the addition method at the time of melt-kneading, it is preferable to melt-knead by adding an epoxy group-containing vinyl monomer and an aromatic vinyl monomer to a mixture obtained by melt-kneading a polyolefin resin and a radical polymerization initiator.

  The processing temperature at the time of melt kneading is preferably 130 to 300 ° C. In the case of 130 ° C. to 300 ° C., the polyolefin resin is sufficiently melted and hardly thermally decomposed.

  Further, the kneading time, that is, the time after mixing the radical polymerization initiator is preferably usually 30 seconds to 60 minutes.

  For melt kneading, an extruder, a Banbury mixer, a kneader, a mill, a heating roll, or the like can be used. From the viewpoint of productivity, it is preferable to use a single-screw or twin-screw extruder. Moreover, in order to improve the miscibility and dispersibility of various raw materials, you may use together the said melt-kneading apparatus.

  Examples of the plastic film include a polyester film, a polyolefin film, a polypropylene film, a polyethylene film, a nylon film, a fluororesin film, a polyamide film, a polyimide film, a polycarbonate film, and a polyphenylene ether film.

  When the modified polyolefin hot melt resin according to the present invention is formed into a film by a melt extrusion method, first, the modified polyolefin hot melt resin is supplied to an extruder, and the resin is heated and melted.

  The modified polyolefin hot melt resin is preferably pre-dried before being supplied to the extruder. By performing such preliminary drying, foaming of the resin extruded from the extruder can be prevented.

  The pre-drying method is not particularly limited. For example, the raw material (that is, the modified polyolefin hot melt resin according to the present invention) can be formed into pellets and the like and can be performed using a hot air dryer or the like. .

  Next, the modified polyolefin hot melt resin heated and melted in the extruder is supplied to the T die. At this time, if a gear pump is used, the uniformity of the extrusion amount of the resin can be improved and thickness unevenness can be reduced.

  Next, the modified polyolefin hot melt resin supplied to the T-die is extruded as a sheet-like molten resin from the T-die, and a plastic film is sandwiched between two laminate rolls from both sides of the sheet-like molten resin and laminated. A three-layer sheet is obtained.

  When obtaining a sheet having a five-layer structure, first, the modified polyolefin hot melt resin supplied to the T-die is extruded from the T-die as a sheet-like molten resin, and sandwiched with plastic from both sides of the sheet-like molten resin and laminated. Thus, a sheet having a three-layer structure is obtained. Thereafter, the modified polyolefin hot melt resin supplied to the T die is extruded from the T die as a sheet-like molten resin, and a plastic film and two sheets of the above three-layer structure are extruded from both sides of the sheet-like molten resin. The laminate is sandwiched between two laminating rolls to obtain a five-layer sheet.

  Of the two laminate rolls sandwiching the sheet-like molten resin, one is a rigid metal roll having a smooth surface, and the other is a flexible roll having an elastic outer cylinder having a smooth surface and capable of elastic deformation. It is preferable that

  With such a rigid metal roll and a flexible roll provided with a metal elastic outer cylinder, the sheet-like molten resin is sandwiched and laminated, whereby a sheet having good adhesion and surface appearance between the films. Can be obtained.

  The surface temperature of the metal roll is preferably 20 ° C. or higher, more preferably 50 ° C. or higher, from the viewpoint of adhesiveness. When the surface temperature of a metal roll is 20 degrees C or less, the adhesive force between films after lamination may be insufficient, which is not preferable. That is, the roll is preferably heated at the time of use.

  On the other hand, the surface temperature of the flexible roll is preferably 150 ° C. or lower, and more preferably 130 ° C. or lower. When the surface temperature of the flexible roll is 150 ° C. or higher, the thermal shrinkage of the film that comes into contact with the roll increases, and the performance may deteriorate.

When bonding the film by extrusion lamination, film tension applied to the plastic film is at 0.7 kgf / m ² or less, more preferably by extrusion laminating at 0.5 kgf / m ² following conditions of each film Sheets having a three-layer structure and a five-layer structure in which the heat shrinkage rates in the MD and TD directions are both 3% or less and the difference in heat shrinkage rate between the films is less than 1.5% are obtained.

  The temperature of the modified polyolefin hot melt resin discharged from the T die is preferably 150 to 300 ° C, and more preferably 170 to 280 ° C. When the temperature is lower than 150 ° C., the melt viscosity is high and uneven thickness of the film may occur, or the inter-film adhesive strength after lamination may be insufficient, which is not preferable. When the temperature exceeds 300 ° C., the melt viscosity of the resin is too low, which makes molding difficult and is not preferable.

  There is no restriction | limiting in particular in the lamination pressure of a metal roll and a flexible roll, The grade from which sufficient adhesive force is acquired is preferable.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited at all by these Examples.

[Polyolefin hot melt resin]
(Production Example 1)
(A-1) Propylene-ethylene copolymer (Versify 3401, MFR8, manufactured by Dow Chemical) 100 parts by weight, 1,3-di (t-butylperoxyisopropyl) benzene (Nippon Yushi Co., Ltd .: Perbutyl P, 0.5 parts by weight of 1 minute half-life (175 ° C) is supplied to a vented meshing co-rotating twin screw extruder (TEX44, L / D = 38, manufactured by Nippon Steel) with a cylinder temperature of 200 ° C. Then, after melt-kneading, 5 parts by weight of (a-2) glycidyl methacrylate and 5 parts by weight of styrene (a-3) were added from the nozzle in the middle of the cylinder to obtain pellets of an epoxy-modified polyolefin resin composition. .

(Production Example 2)
Vented meshing type counter-rotating type 2 in which 0.5 parts by weight of carbon black (manufactured by Tokai Carbon Co .: Sheast V) is set to a cylinder temperature of 200 ° C. with respect to 100 parts by weight of the pellets obtained in Production Example 1. It was supplied to a shaft condenser (20C200, manufactured by Toyo Seiki Seisakusho Co., Ltd.) and melt kneaded. The resin after kneading was pulverized so as to be a lump having a diameter of 0.6 mm or less.

Example 1
3.8 parts by weight of the resin obtained in Production Example 2 is dry blended with 100 parts by weight of the pellets obtained in Production Example 1, dried at 60 ° C. for 15 hours, and then a 40 mmφ single screw extruder and a 400 mm width. And was extruded as a 200 μm sheet-shaped molten resin at 290 ° C.

A PET film (PET film, Shine beam transparent, manufactured by Toyobo Co., Ltd., thickness 50 μm) is sandwiched between both sides of this sheet-like molten resin by a metallic roll heated to 80 ° C. and a silicon rubber film roll heated to 35 ° C. The film was laminated while controlling the film tension at 0.4 kgf / m ² to obtain a three-layer laminated film of PET film / modified polyolefin resin composition / PET film.

(Examples 2 to 6)
In Example 1, the dry blend amount of the resin obtained in Production Example 2 was 8.0 parts by weight in Example 2, 12.5 parts by weight in Example 3, and 12.5 parts by weight in Example 3. Each of the three layers of Examples 2 to 6 was the same as Example 1, except that 14.0 parts by weight in Example 4, 35.0 parts by weight in Example 5, and 90 parts by weight in Example 6 were used. A laminated film was obtained.

(Light transmittance measurement method)
The total transmittance of the films obtained in Examples 1 to 6 was measured with a turbidimeter (NDH-300A, manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Table 1.

  Next, the samples of Examples (1) to (6) were cut into a size of 10 mm × 250 mm (MD longitudinal direction), and interlayer adhesion strength was measured at room temperature using an autograph (AG-2000A, Shimadzu Corporation). The value normalized by the length of the three-layer interface was evaluated as the adhesive strength by measuring the T-peel strength by pulling both ends of the PET film at 200 mm / min. As a result of the evaluation, all of them were 20 N / cm, and good interlayer adhesion was observed.

  From these results, it can be seen that by adding a pigment or dye to the modified polyolefin resin of the present invention, it is possible to adjust the light transmittance and to construct a laminate having excellent interlayer adhesion.

(Example 7)
Glass (heat treated glass for solar cell cover (single-sided embossed), SFN 3.2 mm thickness, manufactured by Asahi Glass Co., Ltd.), vinyl acetate copolymer resin sealing sheet (Ultra Pearl, 0.45 mm thickness, manufactured by Sanvic Co., Ltd.), implementation The back sheet produced in Example (1) was laminated in this order, and was hot-pressed using a vacuum laminator (manufactured by Spire: Spi-Laminator) to obtain a laminate.

(Examples 8 to 12)
In Example 7, the back sheet used was the back sheet produced in Example 2 in Example 8, the back sheet produced in Example 3 in Example 9, and the back sheet produced in Example 4 in Example 10. Each of the laminates of Examples 8 to 12 is the same as Example 7 except that Example 11 is the back sheet produced in Example 5 and Example 12 is the back sheet produced in Example 6. Got.

(Light transmittance measurement method)
The total transmittance of the films obtained in Examples 7 to 12 was measured with a turbidimeter (NDH-300A, manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Table 2.

  Thus, the solar cell module produced using the back sheet using the modified polyolefin resin added with the pigment or dye in the present invention can adjust the light transmittance. As a result, when this back sheet is used, the daylighting property of the solar cell module can be adjusted.

  That is, it is possible to install solar cells in various parts that require high design properties, such as stained glass parts, carport roof parts, automobile sunroof parts, and building materials that emphasize design.

  In addition, it is clear that weight reduction is achieved as compared with a see-through or light-through type solar cell module sealed with two sheets of glass.

  Furthermore, the back sheet of the present invention can also be used as a front sheet, and the solar cell in which cells are sealed with two sheets of the present invention and a sealing material can secure light weight and flexibility. Therefore, it is possible to make a see-through and light-through type solar cell module that can be used in a curved portion by combining with a cell.

Claims (9)

A weather-resistant protective member from the light incident side, a plurality of solar cell elements, and a see-through including a solar cell backsheet, a light-through solar cell module,
The solar cell backsheet includes at least two plastic films sandwiching the adhesive layer; and
100 parts by weight of a polyolefin-based hot melt resin, wherein the material of the adhesive layer is modified with a polar vinyl compound, and 0.0001 to 20 parts by weight of one or more colorants selected from the group consisting of pigments and dyes A see-through solar cell module and a light-through solar cell module.   The see-through and light-through solar cell module according to claim 1, wherein the polyolefin-based hot melt resin is further modified with an aromatic vinyl compound.   The said polar vinyl compound contains the unsaturated polar group which has at least 1 or more types of polar group chosen from the group which consists of an epoxy, unsaturated carboxylic acid, and unsaturated carboxylic anhydride. See-through and light-through solar cell modules.   The polyolefin-based hot melt resin is (a-1) an epoxy group-containing vinyl monomer and (a-3) an aromatic vinyl in the presence of a radical polymerization initiator with respect to the polyolefin-based resin. The see-through and light-through solar cell module according to any one of claims 1 to 4, which is an epoxy-modified polyolefin hot melt resin obtained by melt-kneading a monomer.   In the presence of a radical polymerization initiator, (a-2) 0.5-30 parts by weight of an epoxy group-containing vinyl monomer with respect to 100 parts by weight of the polyolefin-based resin (a-1) And (a-3) an epoxy-modified polyolefin hot melt resin obtained by melt-kneading 0 to 30 parts by weight of an aromatic vinyl monomer, and the see-through and light-through according to claim 5 Solar cell module.   The see-through and light-through solar cell module according to any one of claims 1 to 5, wherein the colorant is a carbon-based material or a dye intended to be colored black.   The see-through and light-through solar cell module according to claim 1, wherein the solar cell backsheet has a total light transmittance of 0 to 70%.   The see-through and light-through solar cell module according to claim 1, wherein the plastic film is a polyester film.   The see-through and light-through solar cell module according to any one of claims 1 to 8, wherein the solar cell back sheet is a back sheet laminated by an extrusion laminating method.