WO2010058695A1

WO2010058695A1 - Backside protective sheet for solar cell and solar cell module provided with same

Info

Publication number: WO2010058695A1
Application number: PCT/JP2009/068708
Authority: WO
Inventors: 篤史渡邉; 昌典橋本
Original assignee: テクノポリマー株式会社
Priority date: 2008-11-21
Filing date: 2009-10-30
Publication date: 2010-05-27
Also published as: JP2013051442A; JP2010153801A; JP2013082927A

Abstract

Disclosed is a backside protective sheet for a solar cell, which comprises a resin layer containing a silicon-containing thermoplastic resin such as a graft polymer resin which is obtained by polymerizing a monomer containing an aromatic vinyl compound in the presence of a silicon-containing rubber. The backside protective sheet for a solar cell may also comprise another resin layer which is bonded to the above-described resin layer. The thickness of the backside protective sheet for a solar cell is preferably 10-1,000 µm. Also disclosed is a solar cell module comprising the backside protective sheet for a solar cell.

Description

Solar cell back surface protective film and solar cell module including the same

The present invention relates to a back surface protective film for a solar cell and a solar cell module including the same, and more specifically, has excellent adhesion to a filler part of a solar cell module including an ethylene / vinyl acetate copolymer composition and the like. The present invention relates to a solar cell back surface protective film and a solar cell module using the same.

In recent years, a solar power generation system including a solar cell module has become widespread as one of power generation means using clean energy. In the solar cell module, a large number of plate-like solar cell elements are arranged, and these are wired in series and in parallel, and packaged to protect the elements and unitized. And this solar cell module usually uses a composition containing an ethylene / vinyl acetate copolymer having a high transparency and excellent moisture resistance by covering the surface of the solar cell element that is exposed to sunlight with a glass plate. Then, after the gap around the solar cell element is filled to form the filler portion, the back surface, that is, the exposed surface of the filler portion is sealed with a protective film made of a resin material.

As a back surface protective film for a solar cell, a film containing a fluororesin, a polyethylene resin, a polyester resin, or the like has been conventionally known. However, the adhesiveness to the filler portion and the long-term durability are not sufficient.
Patent Document 1 discloses a solar cell in which a base film made of polyethylene terephthalate is provided with a thermal adhesive layer including a styrene / olefin copolymer having thermal adhesiveness with a polyolefin resin such as an ethylene / vinyl acetate copolymer. A backside sealing film is disclosed.
Patent Document 2 discloses a film in which a coating film containing a polyurethane resin or an organic silane compound is formed on a base film made of polyethylene terephthalate.
Patent Document 3 discloses a polyester film containing an ethylene terephthalate unit, and a paint containing a crosslinking agent, a polyester resin having a glass transition point of 20 ° C. to 100 ° C., an acrylic resin, and the like. The polyester film for solar cell back surface protective films provided with the coated film was disclosed.

JP 2003-60218 JP 2006-175664 A JP 2007-268710 A

As described in Patent Documents 1 to 3, when the film is provided with an adhesive layer, a certain adhesiveness with the filler part containing the ethylene / vinyl acetate copolymer composition is obtained. The step of forming is separately required, and defects due to uneven coating may occur, and the protection of the filler portion is not always satisfactory.
An object of the present invention is a film which does not have an adhesive layer for adhering to a filler part embedding a solar cell element on its surface, and has adhesiveness, heat resistance and weather resistance to the filler part. An object of the present invention is to provide a solar cell back surface protective film and a solar cell module including the same.

In addition, as described above, the solar cell module is formed by arranging a large number of plate-like solar cell elements, and the sunlight is applied to the back surface protective film for solar cells from the gap between adjacent solar cell elements. There was a leak. And in recent years, in a solar cell module provided with a solar cell element capable of performing photoelectric conversion on both front and back surfaces, studies have been made to give solar cell back surface protective film a function of reflecting sunlight and improve power generation efficiency. .
Another object of the present invention is a film that does not have an adhesive layer for adhering to a filler part that embeds a solar cell element on the surface thereof. An object of the present invention is to provide a back surface protective film for a solar cell including a resin layer having excellent weather resistance and excellent reflectivity to sunlight, particularly light having a wavelength of 400 to 1,400 nm, and a solar cell module including the same.

Moreover, since members, such as a solar cell element in a solar cell module, are easy to see through the filler part containing an ethylene-vinyl acetate copolymer composition etc., it is suppressed and the external appearance property of a solar cell module is improved. For this reason, disposing a dark colored colored layer as a back protective film for solar cells has been studied. However, depending on the constituent material of the dark colored colored layer, sunlight leaked from the gaps between the solar cell elements is absorbed and stored, and the power generation efficiency may be reduced.
Another object of the present invention is a film that does not have an adhesive layer for adhering to a filler part that embeds a solar cell element on the surface thereof. Solar cell back surface protective film including a resin layer having both excellent weather resistance, transparency to light with a wavelength of 800 to 1,400 nm, and absorption with respect to light with a wavelength of 400 to 700 nm, and a solar cell module including the same Is to provide.

The present invention is shown below.
1. A back surface protective film for a solar cell, comprising a resin layer containing a silicon-containing thermoplastic resin (hereinafter also referred to as “first resin layer”).
2. 2. The light having a wavelength of 400 to 1,400 nm is emitted on the surface of the resin layer (first resin layer) in the solar cell back surface protective film, and the reflectance to the light is 50% or more. Back surface protection film for solar cells.
3. 3. The solar cell back surface protective film according to 1 or 2, wherein the resin layer (first resin layer) further contains a white colorant.
4). 2. The resin layer (first resin layer) according to 1 above, wherein the transmittance for light having a wavelength of 800 to 1,400 nm is 60% or more and the absorptance for light having a wavelength of 400 to 700 nm is 60% or more. Back surface protective film for solar cells.
5). The back protective film for a solar cell according to 1 or 4 above, wherein the resin layer (first resin layer) further contains an infrared transmitting colorant.
6). The back surface for solar cells according to any one of 1 to 5 above, wherein the silicon-containing thermoplastic resin contains a graft polymerization resin obtained by polymerizing a monomer containing an aromatic vinyl compound in the presence of a silicon-containing rubber. Protective film.
7). Furthermore, the back surface protective film for solar cells in any one of said 1 thru | or 6 provided with the other resin layer joined to the said resin layer (1st resin layer).
8). 8. The back surface protective film for solar cell as described in 7 above, wherein the other resin layer is a white resin layer.
9. 9. The back protective film for a solar cell according to any one of 1 to 8 above, which has a thickness of 10 to 1,000 μm.
10. A solar cell module comprising the solar cell back surface protective film according to any one of 1 to 9 above.

According to the back surface protective film for a solar cell of the present invention, since the first resin layer containing the silicon-containing thermoplastic resin is provided, the first resin layer and the ethylene / vinyl acetate copolymer embedded in the solar cell element. It is excellent in adhesiveness, heat resistance and weather resistance with a filler part containing a coalescence composition. Therefore, a solar cell module in which the filler part is reliably protected can be provided.
When light having a wavelength of 400 to 1,400 nm is radiated to the surface of the first resin layer in the solar cell back surface protective film, the reflectance of the light is 50% or more. The layer is highly reflective to sunlight, so that when sunlight leaks from the gap between adjacent solar cell elements toward the back surface protective film for solar cells, the reflected light is supplied to the back surface of the solar cell elements. Thus, it can be used for photoelectric conversion to improve power generation efficiency.
Further, when the first thermoplastic resin composition further contains a white colorant, the first resin layer is particularly excellent in reflectivity for sunlight. Therefore, not only in the case of a single layer type film, but also in the case of a laminated film having the first resin layer and another resin layer, etc., depending on the purpose and application, and the filler portion and surface in the first resin layer Even when the member is disposed on the non-side, the effect of improving the power generation efficiency is excellent regardless of the configuration of other resin layers and the like.

In the first resin layer, when the transmittance for light with a wavelength of 800 to 1,400 nm is 60% or more and the absorption with respect to light with a wavelength of 400 to 700 nm is 60% or more, sunlight is When the first resin layer leaks from the gap between adjacent solar cell elements toward the back surface protective film for solar cells, heat storage due to light having the wavelength of 800 to 1,400 nm is suppressed. The heat storage of the filler part bonded to the layer is also suppressed. And the thermal storage in the solar cell module formed using this film is suppressed, and the deformation | transformation of structural members including a film and the fall of electric power generation efficiency can be suppressed. When a member having excellent light reflectivity is disposed on the side of the first resin layer that does not face the filler portion, the light transmitted through the first resin layer is reflected from the surface of the member. Then, the reflected light can be supplied to the back surface of the solar cell element and used for photoelectric conversion to improve power generation efficiency. Moreover, the back surface protective film for solar cells of this invention is a laminated film provided with the 1st resin layer which has this property, and another resin layer as said member, Comprising: Other resin layers are white resin layers. In this case, the same effect can be surely obtained.
When the first thermoplastic resin composition further contains an infrared transmitting colorant, the first resin layer has a transmittance of 60% or more for light having a wavelength of 800 to 1,400 nm, and It is possible to provide a solar cell module having a property that the absorptance with respect to light having a wavelength of 400 to 700 nm is 60% or more and having an excellent dark appearance. And when sunlight hits a film, not only the deformation of the structural members including the film and the decrease in power generation efficiency are suppressed, but also the solar cell provided with the back surface protective film for solar cell of the present invention, When placed on a roof or the like, the appearance of the solar cell is excellent. Furthermore, the back surface protective film for solar cells of the present invention is a laminated film comprising a first resin layer containing an infrared transmitting colorant and another resin layer, and the other resin layer is a white resin layer. In this case, heat storage in the first resin layer and its deformation are suppressed, heat storage in the solar cell module is suppressed, and the effect of improving power generation efficiency is excellent.

When the silicon-containing thermoplastic resin contains a graft polymerization resin obtained by polymerizing a monomer containing an aromatic vinyl compound in the presence of a silicon-containing rubber, hydrolysis resistance, dimensional stability, Excellent impact properties.

According to the solar cell module of the present invention, since the back surface protective film for solar cell of the present invention is provided, it is possible to form a solar cell with excellent shape stability and thereby improved photoelectric conversion efficiency.

It is a schematic sectional drawing which shows an example of the back surface protection film for solar cells of this invention (single layer type). It is a schematic sectional drawing which shows an example of the back surface protection film (lamination type) for solar cells of this invention. It is a schematic sectional drawing which shows the other example of the back surface protection film for solar cells of this invention (lamination | stacking type). It is a schematic sectional drawing which shows an example of the solar cell module of this invention.

Hereinafter, the present invention will be described in detail. In the present specification, “(co) polymerization” means homopolymerization and copolymerization, “(meth) acryl” means acryl and methacryl, and “(meth) acrylate” It means acrylate and methacrylate.

The back surface protective film for solar cells of the present invention is characterized by including a resin layer (first resin layer) containing a silicon-containing thermoplastic resin.

The solar cell back surface protective film of the present invention may be a single-layer film 1A having only the first resin layer (see FIG. 1), the first resin layer 11 and the first resin layer 11. It may be a laminated film (including a laminated sheet) 1B including another layer 15 joined (see FIGS. 2 and 3). The other layer 15 will be described later.
In the present invention, the back protective film for a solar cell is a surface of the first resin layer to adhere to the exposed surface of the filler part of the solar cell module, whether it is a single layer film or a laminated film. Used.

The first resin layer is a flexible layer obtained by using a silicon-containing thermoplastic resin alone or by using a first thermoplastic resin composition containing the silicon-containing thermoplastic resin. As will be described later, the first thermoplastic resin composition may be a composition containing a silicon-containing thermoplastic resin and a silicon-free thermoplastic resin, or a silicon-containing thermoplastic resin, an additive, It may be a composition containing Since the first resin layer can be a single-layer film as described above, the silicon-containing thermoplastic resin and the first thermoplastic resin composition have at least film-forming properties.
Hereinafter, the first thermoplastic resin composition is used for forming the first resin layer, including the case where the first resin layer is formed using only the silicon-containing thermoplastic resin.

The glass transition temperature (hereinafter also referred to as “Tg”) of the thermoplastic resin contained in the first resin layer is preferably 90 ° C. to 220 ° C., more preferably 95 ° C. to 200 ° C., and still more preferably 100 ° C. to 180 ° C., particularly preferably 105 ° C. to 160 ° C. When the glass transition temperature Tg is in the above range, the heat resistance is excellent. In addition, when Tg is too high, it exists in the tendency for the flexibility of the said 1st resin layer to fall. On the other hand, when Tg is too low, the heat resistance tends to be insufficient. The glass transition temperature Tg can be measured by a differential scanning calorimeter (DSC).
In addition, when the 1st thermoplastic resin composition which forms the said 1st resin layer contains several thermoplastic resin, at least 1 resin has Tg of the said range. Preferably, at least one silicon-containing thermoplastic resin has a Tg in the above range.

The silicon-containing thermoplastic resin is a resin containing a silicon atom in the molecule, and is an aromatic vinyl resin (hereinafter referred to as “silicon-containing aromatic vinyl resin”), a polyolefin resin (silicon-containing polyolefin resin), a polycrystal. Vinyl chloride resin (silicon-containing polyvinyl chloride resin), polyvinylidene chloride resin (silicon-containing polyvinylidene chloride resin), saturated polyester resin (silicon-containing saturated polyester resin), polycarbonate resin (silicon-containing polycarbonate resin), polyamide Examples thereof include resins (silicon-containing polyamide-based resins), acrylic resins (silicon-containing acrylic resins), fluororesins (silicon-containing fluorine-based resins), silicon resins, and the like. These can be used alone or in combination of two or more.
The form of the resin obtained by polymerizing the monomer containing the polymerizable unsaturated compound in the silicon-containing thermoplastic resin is obtained by polymerizing the monomer containing the silicon-containing polymerizable unsaturated compound. A resin comprising a (co) polymer; a graft polymerization resin obtained by polymerizing a monomer containing a silicon-containing polymerizable unsaturated compound in the presence of a silicon-free rubber; a silicon-containing rubber in the presence of a silicon-containing rubber Graft polymerization resin obtained by polymerizing monomer not containing polymerizable unsaturated compound; Graft polymerization obtained by polymerizing monomer containing silicon-containing polymerizable unsaturated compound in the presence of silicon-containing rubber Examples thereof include resins. These resins can be used alone or in combination of two or more.
In the present invention, it is derived from an aromatic vinyl compound because it is excellent in adhesiveness, heat resistance and weather resistance with a filler part containing an ethylene / vinyl acetate copolymer composition or the like embedding a solar cell element. A silicon-containing aromatic vinyl resin having a structural unit is preferred.

The content of the silicon-containing thermoplastic resin contained in the first thermoplastic resin composition is preferably 1 to 100% by mass, more preferably 3 to 100%, based on the total amount of the resin component (thermoplastic resin). The mass is more preferably 10 to 90% by mass. If it is the above ratio, the first resin layer containing the first thermoplastic resin composition is embedded in the solar cell element, and has adhesiveness with a filler part containing an ethylene / vinyl acetate copolymer composition, Excellent heat resistance and weather resistance.

On the other hand, the silicon-free thermoplastic resin includes aromatic polyester resin, polyolefin resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and other saturated polyester resins. A monomer that does not contain a silicon-containing polymerizable unsaturated compound in the presence of a polycarbonate resin, a polyamide resin, an acrylic resin containing a structural unit derived from a (meth) acrylic acid ester compound, a fluorine resin, or a silicon-free rubber. Examples thereof include a silicon-free graft polymerization resin (diene graft polymerization resin, acrylic graft polymerization resin, etc.) obtained by polymerization. These resins can be used alone or in combination of two or more.

The silicon-containing aromatic vinyl resin is a silicon-containing resin having a structural unit derived from an aromatic vinyl compound, and is exemplified below.
[1] Silicon-containing copolymer [2] obtained by polymerizing a monomer (hereinafter referred to as “monomer (m1)”) containing an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound. A graft obtained by polymerizing a monomer (hereinafter referred to as “monomer (m2)”) containing an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound in the presence of a silicon-free rubber. Polymerized resin (hereinafter referred to as “graft polymerized resin (g1)”)
[3] Graft polymerization resin (hereinafter referred to as “graft polymerization resin”) obtained by polymerizing a monomer containing an aromatic vinyl compound (hereinafter referred to as “monomer (m3)”) in the presence of silicon-containing rubber. (G2) ".)
Of these, the embodiments [2] to [3] are preferred, and the embodiment [3] is particularly preferred.

The silicon-containing copolymer of the above embodiment [1] is a polymer obtained by polymerizing a monomer (m1) containing an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound.
The aromatic vinyl compound is not particularly limited as long as it is a compound having at least one vinyl bond and at least one aromatic ring. Examples include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, β-methylstyrene, ethylstyrene, p-tert-butylstyrene, vinyltoluene, vinylxylene, vinylnaphthalene, monochlorostyrene, dichloromethane. Examples thereof include styrene, monobromostyrene, dibromostyrene, tribromostyrene, and fluorostyrene. These compounds can be used alone or in combination of two or more. Of these aromatic vinyl compounds, styrene and α-methylstyrene are preferred.

The silicon-containing polymerizable unsaturated compound is not particularly limited as long as it is a compound having a silicon atom and having at least one vinyl bond. For example, a compound represented by the following general formula (1) is used. be able to.
R ¹ Si (OR ² ) ₃ (1)
[Wherein, R ¹ is an organic group having 1 to 20 carbon atoms having at least one carbon-carbon double bond, and R ² is the same or different from each other, and is a hydrogen atom, an aliphatic hydrocarbon group or an aromatic group. Group hydrocarbon group. ]
Examples of the carbon-carbon double bond include a vinyl group, an acryloyl group, a methacryloyl group, an allyl group, a norbornenyl group, and a cyclohexenyl group.

Examples of the silicon-containing polymerizable unsaturated compound represented by the general formula (1) include vinyl trialkoxysilane compounds, 3-methacryloxyalkyltrialkoxysilane compounds, 3-acryloxyalkyltrialkoxysilane compounds, and allyltrialkoxysilanes. Compounds, norbornenyl trialkoxysilane compounds, cyclohexenylethyltrialkoxysilane compounds, and the like.

Examples of the vinyl trialkoxysilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, and vinyltributoxysilane.
Examples of the 3-methacryloxyalkyltrialkoxysilane include 3-methacryloxymethyltrimethoxysilane, 3-methacryloxyethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxymethyltriethoxysilane, Methacryloxyethyltriethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxymethyltripropoxysilane, 3-methacryloxyethyltripropoxysilane, 3-methacryloxypropyltripropoxysilane, 3-methacryloxypropyltributoxy Silane etc. are mentioned.
Examples of the 3-acryloxyalkyltrialkoxysilane include 3-acryloxymethyltrimethoxysilane, 3-acryloxyethyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxymethyltriethoxysilane, 3- Acryloxyethyltriethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxymethyltripropoxysilane, 3-acryloxyethyltripropoxysilane, 3-acryloxypropyltripropoxysilane, 3-acryloxypropyltributoxy Silane etc. are mentioned.
Examples of the allyltrialkoxysilane include allyltrimethoxysilane, allyltriethoxysilane, allyltripropoxysilane, and allyltributoxysilane.
Examples of the norbornenyltrialkoxysilane include norbornenyltrimethoxysilane, norbornenyltriethoxysilane, norbornenyltripropoxysilane, norbornenyltributoxysilane, and the like.
Examples of the cyclohexenylethyltrialkoxysilane include cyclohexenylethyltrimethoxysilane, cyclohexenylethyltriethoxysilane, cyclohexenylethyltripropoxysilane, and cyclohexenylethyltributoxysilane.

Other silicon-containing polymerizable unsaturated compounds other than the above include diethoxymethylvinylsilane, tris (2-methoxyethoxy) vinylsilane, p-vinylphenylmethyldimethoxysilane, 1- (m-vinylphenyl) methyldimethyliso Propoxysilane, 3- (p-vinylphenoxy) propylmethyldiethoxysilane, 3- (p-vinylbenzoyloxy) propylmethyldimethoxysilane, 2- (p-vinylphenyl) ethylmethyldimethoxysilane, 2- (m- Vinylphenyl) ethylmethyldimethoxysilane, 2- (o-vinylphenyl) ethylmethyldimethoxysilane, 1- (p-vinylphenyl) ethylmethyldimethoxysilane, 1- (m-vinylphenyl) ethylmethyldimethoxysilane, 1- ( o-Vinylphenyl) Rumethyldimethoxysilane, 1- (o-vinylphenyl) -1,1,2-trimethyl-2,2-dimethoxydisilane, 1- (p-vinylphenyl) -1,1-diphenyl-3-ethyl-3, 3-diethoxydisiloxane, m-vinylphenyl- [3- (triethoxysilyl) propyl] diphenylsilane, [3- (p-isopropenylbenzoylamino) propyl] phenyldipropoxysilane, N-3- (methacryloxy- 2-hydroxypropyl) -3-aminopropyltriethoxysilane, methacryloxypropyltris (methoxyethoxy) silane, 3- [tris (trimethylsiloxy) silyl] propyl methacrylate, 3- [tris (dimethylvinylsiloxy)] propyl methacrylate, 3- (Trichlorosilyl) propyl Tacrylate, trimethylsilyl methacrylate, tris (trimethylsiloxy) -3-methacryloxypropylsilane, methacryloxypropylmethyldiethoxysilane, acryloxytrimethylsilane, bistrimethylsilyl itaconate, (methacryloxymethyl) bis (trimethylsiloxy) methylsilane, 2- (Trimethylsiloxy) ethyl methacrylate, 2- (acryloxyethoxy) trimethylsilane, 3-methacryloxypropylbis (trimethylsiloxy) methylsilane, (3-acryloxypropyl) methylbis (trimethylsiloxy) silane, (3-acrylic Roxypropyl) dimethylmethoxysilane, (3-acryloxypropyl) tris (trimethylsiloxy) silane, trichlorovinylsilane, allyltrichloro Silane etc. are mentioned.

The above silicon-containing polymerizable unsaturated compounds can be used alone or in combination of two or more.

The monomer (m1) forming the silicon-containing copolymer of the above embodiment [1] may be composed of an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound, and the aromatic vinyl compound and Further, it may be composed of a silicon-containing polymerizable unsaturated compound and another vinyl compound. Other vinyl compounds include vinyl cyanide compounds, (meth) acrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds. Compounds and the like. These can be used alone or in combination of two or more.

Among the other vinyl compounds, examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, ethacrylonitrile, α-chloro (meth) acrylonitrile and the like. These vinyl cyanide compounds may be used alone or in combination of two or more.
Examples of the (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Examples include cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and the like. These (meth) acrylic acid ester compounds may be used alone or in combination of two or more.

Examples of the maleimide compounds include maleimide, N-methylmaleimide, N-butylmaleimide, N-phenylmaleimide, N- (2-methylphenyl) maleimide, N-cyclohexylmaleimide and the like. These maleimide compounds may be used alone or in combination of two or more. In addition, as another method for introducing a structural unit derived from a maleimide compound, for example, a method of copolymerizing maleic anhydride and then imidizing may be used.
Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. These unsaturated acid anhydrides may be used alone or in combination of two or more.

Examples of the hydroxyl group-containing unsaturated compound include 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, and 3-hydroxy- 2-methyl-1-propene, hydroxystyrene, N- (4-hydroxyphenyl) maleimide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate , 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate , 7-hydroxyheptyl (meth) acrylate, (meth) acrylic 8-hydroxy-octyl, (meth) acrylic acid 9-hydroxy-nonyl, (meth) acrylate, 12-hydroxylauryl (meth) acrylic acid 11-hydroxy-undecyl, and (meth) 12-hydroxy dodecyl acrylate. These hydroxyl group-containing unsaturated compounds may be used alone or in combination of two or more.

Examples of the amino group-containing unsaturated compound include aminoethyl (meth) acrylate, propylaminoethyl (meth) acrylate, dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, (meth) acrylic acid 2 -Dimethylaminoethyl, 2-diethylaminoethyl (meth) acrylate, 2- (di-n-propylamino) ethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, 2- (meth) acrylic acid 2- Diethylaminopropyl, 2- (di-n-propylamino) propyl (meth) acrylate, 3-dimethylaminopropyl (meth) acrylate, 3-diethylaminopropyl (meth) acrylate, 3- (di) (meth) acrylate -N-propylamino) propyl, 2-tert- (meth) acrylic acid Butylaminoethyl, phenylaminoethyl (meth) acrylate, 4-aminostyrene, 4-dimethylaminostyrene, N-vinyldiethylamine, N-acetylvinylamine, (meth) acrylamine, N-methyl (meth) acrylamine, etc. Is mentioned. These amino group-containing unsaturated compounds can be used alone or in combination of two or more.

Examples of the amide group-containing unsaturated compound include (meth) acrylamide, N-methylol (meth) acrylamide, 3-dimethylaminopropyl (meth) acrylamide and the like. These amide group-containing unsaturated compounds can be used alone or in combination of two or more.

The content ratio of the structural unit derived from the silicon-containing polymerizable unsaturated compound constituting the silicon-containing copolymer of the above embodiment [1] is preferably 0.01 to 15% by mass with respect to the total amount of the structural unit, More preferably, the content is 0.1 to 10% by mass. If it is the said ratio, the 1st resin layer containing the silicon-containing copolymer of this aspect [1], and the filler part containing an ethylene-vinyl acetate copolymer composition etc. which embeds a solar cell element. Excellent adhesion, heat resistance and weather resistance.
In the silicon-containing copolymer of the above embodiment [1], the content ratio of the structural unit derived from the aromatic vinyl compound and the structural unit derived from the silicon-containing polymerizable unsaturated compound is not particularly limited. The total amount of is preferably 40 to 100% by mass, more preferably 60 to 90% by mass, based on the total amount of the structural units constituting the silicon-containing copolymer. If it is the said ratio, the 1st resin layer containing the silicon-containing copolymer of this aspect [1], and the filler part containing an ethylene-vinyl acetate copolymer composition etc. which embeds a solar cell element. Excellent adhesion, heat resistance and weather resistance.

The weight average molecular weight (hereinafter also referred to as “Mw”) of the silicon-containing copolymer of the above embodiment [1] is preferably 30,000 from the viewpoint of impact resistance, flexibility, film formability, toughness, and the like. To 1,000,000, more preferably 50,000 to 500,000. The Mw can be measured by GPC using standard polystyrene.

The silicon-containing copolymer of the above embodiment [1] is produced by polymerizing the monomer in the presence of a polymerization initiator. As the polymerization method, a known method such as solution polymerization is applied.

The graft polymerization resin (g1) of the above embodiment [2] is obtained by polymerizing a monomer (m2) containing an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound in the presence of a silicon-free rubber. Graft polymerization resin.
The graft polymerization resin (g2) of the above embodiment [3] is a graft polymerization resin obtained by polymerizing the monomer (m3) containing an aromatic vinyl compound in the presence of a silicon-containing rubber.

The components of the non-silicon-containing rubber and silicon-containing rubber (hereinafter also referred to as “rubber component”) used in the above embodiments [2] and [3] will be described below. The shape, size, molecular weight, etc.) are not particularly limited.
The shape of the rubber component is not particularly limited, and may be particulate (spherical or substantially spherical), linear, curved, or the like. In the case of particles, the volume average particle diameter is preferably 5 to 2,000 nm, more preferably 10 to 1,800 nm, and further preferably 50 to 1,500 nm. If the volume average particle diameter is in the above range, the processability of the first thermoplastic resin composition and the impact resistance of the obtained first resin layer are excellent. The volume average particle diameter can be measured by image analysis using an electron micrograph, a laser diffraction method, a light scattering method, or the like.

Examples of the silicon-free rubber include acrylic rubbers; homopolymers such as polybutadiene and polyisoprene, styrene / butadiene copolymers, styrene / isoprene copolymers, and diene rubbers such as natural rubber; conjugated diene compounds. A polymer obtained by hydrogenating a (co) polymer containing units comprising the above (however, the hydrogenation rate is usually 50% or more); an ethylene unit and a unit comprising an α-olefin having 3 or more carbon atoms; And ethylene / α-olefin copolymer rubbers; urethane rubbers and the like. These can be used alone or in combination of two or more.

The acrylic rubber is preferably a (co) polymer containing a structural unit derived from an alkyl acrylate ester compound having an alkyl group with 2 to 8 carbon atoms. The content of the structural unit is preferably 80% by mass or more, more preferably 90% by mass or more, with respect to the total amount of the structural unit.

Examples of the acrylic acid alkyl ester compound include ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, and the like. These compounds can be used alone or in combination of two or more. Of these, acrylic acid alkyl ester compounds are preferably n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate.

When the acrylic rubber contains a structural unit derived from another monomer, the other monomer includes vinyl chloride, vinylidene chloride, vinyl cyanide compound, aromatic vinyl compound, vinyl ester compound, methacrylic acid. Alkyl ester compound, carboxyl group-containing unsaturated compound, methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, propoxymethyl (meth) acrylate, butoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) ) Acrylate, propoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, propoxypropyl (meth) acrylate, butoxypropyl (meth) acrylate, 2-methoxy- Alkoxy group-containing unsaturation such as methyl-propyl (meth) acrylate, 2-propoxy-1-methylpropyl (meth) acrylate, 2-butoxy-1-methylpropyl (meth) acrylate, methoxytripropylene glycol (meth) acrylate Monofunctional monomers such as compounds, hydroxyl group-containing unsaturated compounds, fluorine-containing unsaturated compounds; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol Di- or triallyl such as mono- or polyethylene glycol di (meth) acrylate such as di (meth) acrylate, divinylbenzene, diallyl phthalate, diallyl maleate, diallyl succinate, triallyl triazine Compounds, allyl (meth) allyl compounds such as acrylates, such as conjugated diene compound, 1,3-butadiene, etc., a polyfunctional monomer or the like having two or more unsaturated bonds. In the present invention, the other monomer preferably contains a polyfunctional monomer. That is, the acrylic rubber is preferably a copolymer containing a structural unit derived from the polyfunctional monomer.
The content of the structural unit derived from the polyfunctional monomer constituting the preferred acrylic rubber is preferably from 0.01 to the total amount of the structural unit from the viewpoint of low-temperature impact properties, flexibility, and the like. It is 10% by mass, more preferably 0.05 to 8% by mass, and still more preferably 0.1 to 5% by mass.

The Tg of the acrylic rubber is preferably −10 ° C. or lower from the viewpoint of low temperature impact property, flexibility, and the like.

Examples of the method for producing the acrylic rubber include emulsion polymerization. In this case, the volume average particle size and the like can be adjusted by selecting production conditions such as the type of emulsifier and the amount used, the type of initiator and the amount used, polymerization time, polymerization temperature, and stirring conditions. . Moreover, as another adjustment method of the said volume average particle diameter (particle diameter distribution), the method of blending 2 or more types of the said acrylic rubber which has a different particle diameter may be sufficient.

Examples of the silicon-containing rubber include a silicon-containing polymerizable unsaturated compound and at least one selected from conjugated diene compounds such as butadiene, α-olefin compounds such as ethylene and propylene, and alkyl acrylate compounds. Rubber obtained by copolymerization of a monomer (hydrogenated rubber may be used); silicone rubber comprising polyorganosiloxane obtained by polycondensation of one or more organosiloxanes; organosiloxane and silicon-containing crosslink Obtained by using an agent (a saturated silane compound having 3 or 4 alkoxy groups); rubber obtained by using an organosiloxane and a silicon-containing polymerizable unsaturated compound; an organosiloxane and a silicon-containing crosslink Obtained using an agent (a saturated silane compound having 3 or 4 alkoxy groups) and a silicon-containing polymerizable unsaturated compound A conjugated diene compound, at least one silicon-free polymerizable unsaturated compound selected from an aromatic vinyl compound, a vinyl cyanide compound, a (meth) acrylic acid ester compound, and the like, and a silicon-containing coupling agent (alkyl And dichlorosilane compounds, alkyltrichlorosilane compounds, dialkylchlorosilane compounds, trichlorosilane, tetrachlorosilane, tetraalkoxysilane compounds, etc.). The silicon-containing rubber can be used singly or in combination of two or more. In addition, when two or more of the silicon-containing rubbers are combined, and when at least one of the silicon-containing rubbers is combined with another rubber, it may be referred to as a composite rubber. In rubber, a plurality of rubbers may be chemically bonded, may have entanglement, or may be a mere coexisting substance.

The silicon-containing rubber is a rubber obtained by copolymerizing a monomer containing a silicon-containing polymerizable unsaturated compound and an alkyl acrylate ester compound (hereinafter referred to as “silicon-containing rubber (s1)”). A rubber obtained by using an organosiloxane and a silicon-containing polymerizable unsaturated compound (hereinafter referred to as “silicon-containing rubber (s2)”), an organosiloxane, and a silicon-containing crosslinking agent (3 or 4 alkoxy groups). And a rubber obtained using a silicon-containing polymerizable unsaturated compound (hereinafter referred to as “silicon-containing rubber (s3)”) and a composite rubber (hereinafter referred to as “silicon-containing rubber ( s4) ") is preferred.

Of the monomers used for the formation of the silicon-containing rubber (s1), the compounds exemplified in the above embodiment [1] can be used as the silicon-containing polymerizable unsaturated compound. These compounds can be used alone or in combination of two or more. Of these, the silicon-containing polymerizable unsaturated compounds are p-vinylphenylmethyldimethoxysilane, 2- (p-vinylphenyl) ethylmethyldimethoxysilane and 3- (p-vinylbenzoyloxy) propylmethyldimethoxysilane. P-vinylphenylmethyldimethoxysilane is particularly preferred. The content of the silicon-containing polymerizable unsaturated compound contained in 100% by mass of the monomer is preferably 0.01 to 15% by mass, more preferably 0.1 to 10% by mass.
The acrylic acid alkyl ester compound is preferably an acrylic acid alkyl ester having an alkyl group having 2 to 8 carbon atoms, and the compounds exemplified in the acrylic acid alkyl ester compound used for forming the acrylic rubber may be used. it can. These compounds can be used alone or in combination of two or more. Of these, acrylic acid alkyl ester compounds are preferably n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate. The content of the alkyl acrylate ester compound contained in 100% by mass of the monomer is preferably 85 to 99.99% by mass, more preferably 90 to 99.9% by mass.

The monomer used for forming the silicon-containing rubber (s1) may be composed of a silicon-containing polymerizable unsaturated compound and an acrylic acid alkyl ester compound, or a silicon-containing polymerizable unsaturated compound and acrylic. It may consist of an acid alkyl ester compound and another polymerizable compound. Other polymerizable compounds include vinyl cyanide compounds, aromatic vinyl compounds, methacrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, and amide group-containing compounds. Examples thereof include unsaturated compounds, alkoxy group-containing unsaturated compounds, fluorine-containing unsaturated compounds, and polyfunctional monomers having two or more unsaturated bonds. These can be used alone or in combination of two or more.
In this invention, it is preferable that the said monomer contains a polyfunctional monomer, and the compound illustrated in the polyfunctional monomer used for formation of the said acrylic rubber can be used. The amount used is preferably 10% by mass or less, more preferably 5% by mass or less, with respect to 100% by mass of the monomer.

The Tg of the silicon-containing rubber (s1) is preferably −10 ° C. or less from the viewpoint of low temperature impact property, flexibility, and the like.

The silicon-containing rubber (s2) is a rubber obtained by using an organosiloxane and a silicon-containing polymerizable unsaturated compound, and is a polyorganosiloxane rubber containing an organosiloxane segment and another segment.
The silicon-containing rubber (s3) is a rubber obtained by using organosiloxane, a silicon-containing crosslinking agent (a saturated silane compound having 3 or 4 alkoxy groups), and a silicon-containing polymerizable unsaturated compound. Yes, it is a polyorganosiloxane rubber containing an organosiloxane segment and other segments.
The silicon-containing rubbers (s2) and (s3) are preferably obtained in a latex state by emulsion polymerization, for example, US Pat. Nos. 2,891,920 and 3,294,725. The polyorganosiloxane rubber produced by the method described in the above.

The polyorganosiloxane rubber is obtained by, for example, shear-mixing organosiloxane and water in the presence of a sulfonic acid-based emulsifier such as alkylbenzenesulfonic acid or alkylsulfonic acid using a homomixer or an ultrasonic mixer. The silicone rubber contained in the latex obtained by the condensation method is preferable. Alkylbenzenesulfonic acid is suitable because it acts as an emulsifier for organosiloxane and also as a polymerization initiator. In this case, it is preferable to use an alkylbenzene sulfonic acid metal salt, an alkyl sulfonic acid metal salt, or the like in combination because it has an effect of stably maintaining the silicone rubber when the graft polymerization resin is produced. In the present invention, when the organosiloxane is used, a silicon-containing polymerizable unsaturated compound is used in combination, and the polymer terminal may be sealed with a dimethylvinylsilyl group, a methylphenylvinylsilyl group, or the like. Good. Moreover, the terminal of the polyorganosiloxane rubber may be sealed with, for example, a hydroxyl group, an alkoxy group, a trimethylsilyl group, a methyldiphenylsilyl group, or the like.

The organosiloxane used in the above reaction is, for example, a compound having a structural unit represented by the following general formula (2).
(R _m SiO _{(4-m) / 2} ) (2)
[Wherein, R represents a substituted or unsubstituted monovalent hydrocarbon group, and m represents an integer of 0 to 3. ]
The structure of the compound represented by the general formula (2) is linear, branched or cyclic, but the compound is preferably an organosiloxane having a cyclic structure. R which this organosiloxane has, that is, monovalent hydrocarbon group includes alkyl group such as methyl group, ethyl group, propyl group and butyl group; aryl group such as phenyl group and tolyl group; vinyl group, allyl group and the like And a group in which some of the hydrogen atoms bonded to carbon atoms in these hydrocarbon groups are substituted with halogen atoms, cyano groups, etc .; and at least one of the hydrogen atoms in the alkyl group is substituted with a mercapto group And the like.

Examples of the organosiloxane include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, and octaphenylcyclotetrasiloxane. In addition to a cyclic compound such as a linear or branched organosiloxane. These can be used alone or in combination of two or more.
The organosiloxane may be a polyorganosiloxane condensed in advance, for example, having an Mw of about 500 to 10,000. When the organosiloxane is a polyorganosiloxane, the molecular chain terminal may be sealed with a hydroxyl group, an alkoxy group, a trimethylsilyl group, a methyldiphenylsilyl group, or the like.

Further, as the silicon-containing polymerizable unsaturated compound used in the above reaction, the compounds exemplified in the above embodiment [1] can be used. These compounds can be used alone or in combination of two or more. Of these, the silicon-containing polymerizable unsaturated compounds are p-vinylphenylmethyldimethoxysilane, 2- (p-vinylphenyl) ethylmethyldimethoxysilane and 3- (p-vinylbenzoyloxy) propylmethyldimethoxysilane. P-vinylphenylmethyldimethoxysilane is particularly preferred.

In the production of the silicon-containing rubbers (s2) and (s3), when the organosiloxane and the silicon-containing polymerizable unsaturated compound are used in combination, the amount of the silicon-containing polymerizable unsaturated compound used is the sum of these. The amount is preferably 0.01 to 15% by mass, more preferably 0.05 to 12% by mass, and still more preferably 0.1 to 10% by mass with respect to 100% by mass. If the amount of the silicon-containing polymerizable unsaturated compound used is too large, the resulting first resin layer may not have sufficient impact resistance and weather resistance.

Examples of the silicon-containing crosslinking agent used in the production of the silicon-containing rubber (s3) include trifunctional crosslinking agents such as methyltrimethoxysilane, ethyltrimethoxysilane, phenyltrimethoxysilane, and ethyltriethoxysilane, and tetraethoxysilane. And a tetrafunctional cross-linking agent. A crosslinkable prepolymer obtained by condensation polymerization of these compounds in advance may be used. These may be used alone or in combination of two or more.
The first resin layer containing a graft polymerization resin obtained by polymerizing a monomer (m3) containing an aromatic vinyl compound in the presence of the silicon-containing rubber (s3) obtained using the silicon-containing crosslinking agent Especially excellent in impact resistance.

The amount of the silicon-containing crosslinking agent used in the production of the silicon-containing rubber (s3) is 100 mass of the total amount of the organosiloxane, the graft crossing agent (usually a silicon-containing polymerizable unsaturated compound) and the silicon-containing crosslinking agent. % Is usually 10% by mass or less, preferably 5% by mass or less, and more preferably 0.01 to 5% by mass. When the usage-amount of the said silicon-containing crosslinking agent exceeds 10 mass%, the softness | flexibility of the polyorganosiloxane type rubber obtained may be impaired, and the flexibility of the 1st resin layer obtained may fall.

The amount of the emulsifier used in the production of the silicon-containing rubber (s2) or (s3) is usually 0.1 to 5 parts by mass with respect to 100 parts by mass of the total amount of the organosiloxane and the silicon-containing polymerizable unsaturated compound. The amount is preferably 0.3 to 3 parts by mass.
The amount of water used in the production of the silicon-containing rubber (s2) or (s3) is usually 100 to 500 parts by weight, preferably 100 parts by weight, based on the total amount of organosiloxane and silicon-containing polymerizable unsaturated compound. Is 200 to 400 parts by mass.
The condensation temperature in the production of the silicon-containing rubber (s2) or (s3) is usually 5 ° C. to 100 ° C.

The volume average particle diameter of the silicon-containing rubbers (s2) and (s3) is usually 500 nm or less, preferably 400 nm or less, more preferably 50 to 400 nm. When the volume average particle diameter is 500 nm or less, the processability of the first thermoplastic resin composition and the impact resistance of the obtained first resin layer are excellent. On the other hand, when the volume average particle diameter exceeds 500 nm, the appearance of the first resin layer tends to be inferior, for example, the glossiness is lowered.
The volume average particle size is determined by the amount of emulsifier and water used in the production of the silicon-containing rubbers (s2) and (s3), the method of adding the organosiloxane, and the dispersion when using a homomixer or an ultrasonic mixer. It can be easily controlled depending on the degree.

The Tg of the silicon-containing rubber (s2) is preferably −150 ° C. to −30 ° C. from the viewpoint of low temperature impact property, flexibility, and the like.
The Tg of the silicon-containing rubber (s3) is preferably −150 ° C. to −30 ° C. from the viewpoint of low temperature impact property, flexibility, and the like.

The composite rubber (s4) is exemplified below. In these embodiments, as described above, the rubbers may be chemically bonded, may have entanglement, or may be a mere coexisting substance.
(1) Combination of the silicon-containing rubbers (s1) and (s2) (2) Combination of the silicon-containing rubbers (s1) and (s3) (3) Silicone-containing rubbers (s1), (s2) and (s3) (4) Combination of acrylic rubber and silicon-containing rubber (s2) (5) Combination of acrylic rubber and silicon-containing rubber (s3) (6) Acrylic rubber, silicon-containing rubber (s2) and ( Combination of s3)

The composite rubbers of the above aspects (4) to (6) can be produced, for example, by the method described in JP-A-4-239010. Examples of commercially available products in these embodiments include “Metablene SX-006” (trade name) manufactured by Mitsubishi Rayon Co., Ltd.

The graft polymerization resins (g1) and (g2) according to the above embodiments [2] and [3] are resins generally referred to as rubber-reinforced resins. As a result of the polymerization of the monomer around the rubber, the rubber The resin having a graft polymer portion on at least the surface and the inside.

Examples of the silicon-free rubber used for forming the graft polymerization resin (g1) in the above embodiment [2] include acrylic rubber and diene rubber, and acrylic rubber is preferable.

As the aromatic vinyl compound and the silicon-containing polymerizable unsaturated compound contained in the monomer (m2) used for forming the graft polymerization resin (g1), the compounds exemplified in the above embodiment [1] can be used. The proportions of the aromatic vinyl compound and the silicon-containing polymerizable unsaturated compound contained in the monomer (m2) are preferably 85 to 99.99% by mass when the total of these is 100% by mass and 0.01 to 15% by mass, more preferably 90 to 99.95% by mass and 0.05 to 10% by mass.

The monomer (m2) may be composed of an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound, an aromatic vinyl compound, a silicon-containing polymerizable unsaturated compound, and another vinyl. It may consist of a system compound. In the latter case, the ratio of the total amount of the aromatic vinyl compound and the silicon-containing polymerizable unsaturated compound contained in the monomer (m2) is usually 60% by mass or more. Other vinyl compounds include vinyl cyanide compounds, (meth) acrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds. A compound, an epoxy group-containing unsaturated compound, an oxazoline group-containing unsaturated compound, and the like. These can be used alone or in combination of two or more.

The graft polymerization resin (g1) is produced by polymerizing the monomer (m2) in the presence of the silicon-free rubber, but the production method is not particularly limited. , Emulsion polymerization, solution polymerization, bulk polymerization and the like can be applied.
The proportions of the used amounts of the non-silicon-containing rubber and the monomer (m2) used in the production of the graft polymerization resin (g1) are as follows. ) Is preferably 25 to 400 parts by mass, more preferably 40 to 300 parts by mass.

In addition, the monomer (m3) used for forming the graft polymerization resin (g2) of the above embodiment [3] may be composed only of an aromatic vinyl compound, or an aromatic vinyl compound and silicon-containing polymerization. It may consist of other vinyl compounds excluding the unsaturated organic compounds. In the latter case, the proportion of the aromatic vinyl compound contained in the monomer (m3) is preferably 20% by mass or more and less than 100% by mass, more preferably 40 to 90% by mass. Other vinyl compounds include vinyl cyanide compounds, (meth) acrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds. A compound, an epoxy group-containing unsaturated compound, an oxazoline group-containing unsaturated compound, and the like. These can be used alone or in combination of two or more.

The graft polymerization resin (g2) is produced by polymerizing the monomer (m3) in the presence of the silicon-containing rubber, but the production method is not particularly limited. Emulsion polymerization, solution polymerization, bulk polymerization and the like can be applied.
The amount of the silicon-containing rubber and the monomer (m3) used in the production of the graft polymerization resin (g2) is such that the monomer (m3) is based on 100 parts by mass of the silicon-containing rubber. The amount is preferably 25 to 400 parts by mass, more preferably 40 to 300 parts by mass.

In the present invention, the above silicon-containing aromatic vinyl resin may be combined with other thermoplastic resins. Another thermoplastic resin is a resin that contains a silicon atom in the molecule and does not contain a structural unit derived from an aromatic vinyl compound, and a resin that contains no silicon atom in the molecule and contains a structural unit derived from an aromatic vinyl compound And a resin that does not contain a silicon atom in the molecule and does not contain a structural unit derived from an aromatic vinyl compound.

As a resin that contains a silicon atom in the molecule and does not contain a structural unit derived from an aromatic vinyl compound, a resin that does not contain an aromatic vinyl compound in the presence of a silicon-containing rubber (hereinafter referred to as “monomer (m4 ) ”)), A graft polymer resin (hereinafter referred to as“ graft polymer resin (g3) ”), a silicon-containing acrylic resin, a silicon-containing polyolefin resin, a silicon-containing polyvinyl chloride resin, Examples thereof include silicon-containing polyvinylidene chloride resins, silicon-containing saturated polyester resins, silicon-containing polycarbonate resins, silicon-containing polyamide resins, silicon-containing fluorine resins, and silicon resins.

As a resin containing a structural unit that does not contain a silicon atom in the molecule and is derived from an aromatic vinyl compound, a monomer containing an aromatic vinyl compound (hereinafter referred to as “monomer (m5)”) is polymerized. The monomer (hereinafter referred to as “monomer (m6)”) containing an aromatic vinyl compound is polymerized in the presence of the aromatic vinyl (co) polymer obtained and the silicon-free rubber. Examples thereof include a non-silicon-containing graft polymerization resin (hereinafter referred to as “graft polymerization resin (g4)”).

Examples of the resin that does not contain a silicon atom in the molecule and does not contain a structural unit derived from an aromatic vinyl compound include polyolefin resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene. Saturated polyester resins such as terephthalate and polyethylene naphthalate, polycarbonate resins, polyamide resins, acrylic resins containing structural units derived from (meth) acrylic acid ester compounds, fluororesins, and aromatic vinyl compounds in the presence of silicon-free rubber , A silicon-free graft polymerization resin (hereinafter referred to as “graft polymerization resin (g5)” obtained by polymerizing a monomer containing no silicon-containing polymerizable unsaturated compound (hereinafter referred to as “monomer (m7)”). ) "Etc.). Examples of the graft polymerization resin (g5) include diene graft polymerization resins and acrylic graft polymerization resins.

When the first thermoplastic resin composition is composed of a silicon-containing aromatic vinyl resin and another thermoplastic resin as a resin component, a combination of a silicon-containing aromatic vinyl resin and a graft polymerization resin (g4), A combination of a silicon-containing aromatic vinyl resin and a graft polymerization resin (g5) can be used.

As described above, the silicon-containing thermoplastic resin may be a resin other than the silicon-containing aromatic vinyl resin, and specific examples thereof include an aromatic vinyl compound in addition to the graft polymerization resin (g3). Examples thereof include a silicon-containing copolymer obtained by polymerizing a monomer containing a polymerizable unsaturated compound not included and a silicon-containing polymerizable unsaturated compound.
These resins are aromatic compounds obtained by polymerizing the resin component of the above embodiments [1] to [3] and a monomer containing an aromatic vinyl compound (hereinafter referred to as “monomer (m5)”). It can be used in combination with a resin having a structural unit derived from an aromatic vinyl compound, such as a vinyl (co) polymer and the above graft polymerization resin (g4). It is excellent in adhesiveness, heat resistance and weather resistance with a filler part containing an ethylene / vinyl acetate copolymer composition and the like embedding a solar cell element.

The resin component contained in the first thermoplastic resin composition is an aromatic vinyl (co) polymer obtained by polymerizing a graft polymerization resin (g3) and a monomer (m5), and a graft polymerization resin. A case where the resin is a combination of at least one selected from (g4) (hereinafter referred to as “aspect [4]”) will be described.
That is, the above aspect [4] is exemplified below.
(4-1) A resin comprising a graft polymerization resin (g3) and an aromatic vinyl (co) polymer (4-2) A graft polymerization resin (g3) and a silicon-free graft polymerization resin (g4) Resin (4-3) A resin comprising a graft polymerization resin (g3), a silicon-free graft polymerization resin (g4), and an aromatic vinyl (co) polymer

As the silicon-containing rubber used for forming the graft polymerized resin (g3), the silicon-containing rubbers (s1) to (s4) are preferable.
Moreover, as a monomer (m4) used for formation of the graft polymerization resin (g3), a vinyl cyanide compound, a (meth) acrylic acid ester compound, a maleimide compound, an unsaturated acid anhydride, a hydroxyl group-containing unsaturated compound At least one compound selected from a compound, an amino group-containing unsaturated compound, an amide group-containing unsaturated compound, an epoxy group-containing unsaturated compound, an oxazoline group-containing unsaturated compound, and the like is used.

The graft polymerization resin (g3) is produced by polymerizing the monomer (m4) in the presence of the silicon-containing rubber, but the production method is not particularly limited. Emulsion polymerization, solution polymerization, bulk polymerization and the like can be applied.
The amount of the silicon-containing rubber and the monomer (m4) used in the production of the graft polymerization resin (g3) is such that the monomer (m4) is based on 100 parts by mass of the silicon-containing rubber. The amount is preferably 25 to 400 parts by mass, more preferably 40 to 300 parts by mass.

The monomer (m5) used for the formation of the aromatic vinyl (co) polymer may be composed only of an aromatic vinyl compound, or an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound. It may consist of other vinyl compounds. In the latter case, the proportion of the aromatic vinyl compound contained in the monomer (m5) is preferably 20% by mass or more and less than 100% by mass, more preferably 40 to 90% by mass. Other vinyl compounds include vinyl cyanide compounds, (meth) acrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds. A compound, an epoxy group-containing unsaturated compound, an oxazoline group-containing unsaturated compound, and the like. These can be used alone or in combination of two or more. Of these, vinyl cyanide compounds are preferred.

The aromatic vinyl (co) polymer is produced by polymerizing the monomer (m5), but the production method is not particularly limited. For example, emulsion polymerization, solution polymerization, bulk Polymerization or the like can be applied.

Examples of the silicon-free rubber used for forming the silicon-free graft polymerization resin (g4) include acrylic rubber and diene rubber, and acrylic rubber is preferable.

The monomer (m6) used for forming the silicon-free graft polymerization resin (g4) may be composed of only an aromatic vinyl compound, or an aromatic vinyl compound and a silicon-containing polymerizable unsaturated compound. It may consist of other vinyl compounds. In the latter case, the ratio of the aromatic vinyl compound contained in the monomer (m6) is preferably 20% by mass or more and less than 100% by mass, more preferably 40 to 90% by mass. Other vinyl compounds include vinyl cyanide compounds, (meth) acrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds. A compound, an epoxy group-containing unsaturated compound, an oxazoline group-containing unsaturated compound, and the like. These can be used alone or in combination of two or more.

The silicon-free graft polymerized resin (g4) is produced by polymerizing the monomer (m6) in the presence of the silicon-free rubber, but the production method is particularly limited. For example, emulsion polymerization, solution polymerization, bulk polymerization, and the like can be applied.
The amount of the silicon-free rubber and the monomer (m6) used in the production of the silicon-free graft polymerization resin (g4) is as follows. The body (m6) is preferably 25 to 400 parts by mass, more preferably 40 to 300 parts by mass.

In the above embodiment [4], in the case of the above embodiment (4-1), the content ratios of the graft polymerization resin (g3) and the aromatic vinyl (co) polymer are not particularly limited, but the graft polymerization resin (g3) The content ratio of the silicon-containing rubber used for the formation is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, based on the entire resin component. When the content ratio of the silicon-containing rubber is in the above range, the resulting first resin layer is excellent in impact resistance.

In the above aspect [4], in the case of the above aspect (4-2), the content ratio of the graft polymerization resin (g3) and the silicon-free graft polymerization resin (g4) is not particularly limited, but the graft polymerization resin (g3) The ratio of the total content of the silicon-containing rubber used for forming the silicon-free rubber and the silicon-free rubber used for forming the silicon-free graft polymerized resin (g4) is preferably 3 to 40 based on the entire resin component. The mass is selected to be 5% by mass, more preferably 5 to 30% by mass. When the ratio of the total content of the rubber components is in the above range, the resulting first resin layer is excellent in impact resistance.

In the above aspect [4], in the case of the above aspect (4-3), the content ratios of the graft polymerization resin (g3), the silicon-free graft polymerization resin (g4) and the aromatic vinyl (co) polymer are particularly limited. Although the ratio of the total content of the silicon-containing rubber used for the formation of the graft polymerization resin (g3) and the silicon-free rubber used for the formation of the silicon-free graft polymerization resin (g4) is not Is preferably 3 to 40% by mass, more preferably 5 to 30% by mass. When the ratio of the total content of the rubber components is in the above range, the resulting first resin layer is excellent in impact resistance.

The resin component contained in the first thermoplastic resin composition is a graft polymerization resin (g4) and a resin selected from the above embodiments [1] to [3], which is a silicon-containing aromatic vinyl resin. A case where the resins are combined (hereinafter referred to as “aspect [5]”) will be described.
That is, the above aspect [5] is exemplified below.
(5-1) A resin comprising the silicon-free graft polymerization resin (g4) and the silicon-containing copolymer of the above embodiment [1] (5-2) a silicon-free graft polymerization resin (g4) and the above embodiment [ 2], that is, a resin comprising the graft polymerization resin (g1) (5-3) a silicon-free graft polymerization resin (g4), and the resin of the above embodiment [3], ie, the graft polymerization resin (g2). Resin consisting of

In the above embodiment [5], in the case of the above embodiment (5-1), the content ratios of the silicon-free graft polymerization resin (g4) and the silicon-containing copolymer of the above embodiment [1] are not particularly limited. The content ratio of the non-silicon-containing rubber used for forming the non-containing graft polymerization resin (g4) is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, based on the entire resin component. Selected. When the content ratio of the non-silicon-containing rubber is within the above range, the resulting first resin layer is excellent in impact resistance.

In the above aspect [5], in the case of the above aspect (5-2), the content ratios of the silicon-free graft polymerization resin (g4) and the graft polymerization resin (g1) are not particularly limited. The ratio of the total content of the silicon-free rubber used for forming (g4) and the silicon-free rubber used for forming the graft polymerization resin (g1) is preferably 3 to It is selected to be 40% by mass, more preferably 5 to 30% by mass. When the ratio of the total content of the rubber components is in the above range, the resulting first resin layer is excellent in impact resistance.

In the above aspect [5], in the case of the above aspect (5-3), the content ratios of the silicon-free graft polymerization resin (g4) and the graft polymerization resin (g2) are not particularly limited. The ratio of the total content of the silicon-free rubber used for the formation of (g4) and the silicon-containing rubber used for the formation of the graft polymerization resin (g2) is preferably 3 to 40 with respect to the entire resin component. The mass is selected to be 5% by mass, more preferably 5 to 30% by mass. When the ratio of the total content of the rubber components is in the above range, the resulting first resin layer is excellent in impact resistance.

Further, the resin component contained in the first thermoplastic resin composition polymerizes a monomer (m7) that does not contain an aromatic vinyl compound or a silicon-containing polymerizable unsaturated compound in the presence of a silicon-free rubber. When the obtained resin is a combination of the non-silicon-containing graft polymerization resin (g5) and a resin selected from the above embodiments [1] to [5] which is a silicon-containing aromatic vinyl resin (hereinafter referred to as an embodiment). [6]) will be described.
That is, the above aspect [6] is exemplified below.
(6-1) A resin comprising the silicon-free graft polymerization resin (g5) and the silicon-containing copolymer of the above-mentioned embodiment [1] (6-2) a silicon-free graft polymerization resin (g5) and the above-mentioned embodiment [ 2], that is, a resin comprising a graft polymerization resin (g1) (6-3) a silicon-free graft polymerization resin (g5), and a resin of the above embodiment [3], ie, a graft polymerization resin (g2). A resin (6-4) containing no silicon-containing graft polymerization resin (g5) and a resin (6-5) containing no silicon-containing graft polymerization resin (g5) and the above embodiment [5]. A resin comprising

Examples of the silicon-free rubber used for forming the silicon-free graft polymerization resin (g5) include acrylic rubber and diene rubber, and acrylic rubber is preferable.

Examples of the monomer (m7) used for forming the silicon-free graft polymerization resin (g5) include vinyl cyanide compounds, (meth) acrylic acid ester compounds, maleimide compounds, unsaturated acid anhydrides, hydroxyl group-containing compounds. At least one compound selected from a saturated compound, an amino group-containing unsaturated compound, an amide group-containing unsaturated compound, an epoxy group-containing unsaturated compound, an oxazoline group-containing unsaturated compound, and the like is used.

The silicon-free graft polymerization resin (g5) is produced by polymerizing the monomer (m7) in the presence of the silicon-free rubber, but its production method is particularly limited. For example, emulsion polymerization, solution polymerization, bulk polymerization, and the like can be applied.
The amount of the silicon-free rubber and the monomer (m7) used in the production of the silicon-free graft polymerization resin (g5) is such that the amount of the single monomer is 100 parts by mass of the silicon-free rubber. The body (m7) is preferably 25 to 400 parts by mass, more preferably 40 to 300 parts by mass.

In the above aspect [6], in the case of the above aspect (6-1), the content ratios of the silicon-free graft polymerization resin (g5) and the silicon-containing copolymer of the above aspect [1] are not particularly limited. The content ratio of the non-silicon-containing rubber used for forming the non-containing graft polymerization resin (g5) is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, based on the entire resin component. Selected. When the content ratio of the non-silicon-containing rubber is within the above range, the resulting first resin layer is excellent in impact resistance.

In the above aspect [6], in the case of the above aspect (6-2), the content ratios of the non-silicon-containing graft polymerization resin (g5) and the graft polymerization resin (g1) are not particularly limited. The total content of the non-silicon-containing rubber used for forming (g5) and the non-silicon-containing rubber used for forming the graft polymerization resin (g1) is preferably 3 to It is selected to be 40% by mass, more preferably 5 to 30% by mass. When the ratio of the total content of the silicon-free rubber is within the above range, the resulting first resin layer is excellent in impact resistance.

In the above aspect [6], in the case of the above aspect (6-3), the content ratio of the silicon-free graft polymerization resin (g5) and the graft polymerization resin (g2) is not particularly limited. The ratio of the total content of the silicon-free rubber used for the formation of (g5) and the silicon-containing rubber used for the formation of the graft polymerization resin (g2) is preferably 3 to 40 with respect to the entire resin component. The mass is selected to be 5% by mass, more preferably 5 to 30% by mass. When the ratio of the total content of the silicon-free rubber and the silicon-containing rubber is within the above range, the resulting first resin layer is excellent in impact resistance.

In the above embodiment [6], in the case of the above embodiment (6-4), the content ratio of the silicon-free graft polymerization resin (g5) and the resin of the above embodiment [4] is not particularly limited, but silicon-free graft polymerization The ratio of the total content of the non-silicon-containing rubber used for forming the resin (g5) and the rubber component contained in the resin of the above aspect [4] is preferably 3 to 40 mass with respect to the entire resin component. %, More preferably 5 to 30% by mass. When the ratio of the total content of the rubber components is in the above range, the resulting first resin layer is excellent in impact resistance.

In the above embodiment [6], in the case of the above embodiment (6-5), the content ratio of the silicon-free graft polymerization resin (g5) and the resin of the above embodiment [5] is not particularly limited, but silicon-free graft polymerization is not limited. The proportion of the total content of the non-silicon-containing rubber used for forming the resin (g5) and the rubber component contained in the resin of the above embodiment [5] is preferably 3 to 40 mass with respect to the entire resin component. %, More preferably 5 to 30% by mass. When the ratio of the total content of the rubber components is within the above range, the resulting first resin layer is excellent in impact resistance.

As the production method of the graft polymerization resins (g1) to (g5), a known method can be applied as described above, and a production method by emulsion polymerization will be described below.
In emulsion polymerization, in addition to rubber components and monomers (meaning monomers (m2), (m3), (m4), (m6) and (m7)), usually polymerization initiators and chain transfer agents (Molecular weight regulator), emulsifier, water and the like are used.

As the polymerization initiator, a redox in which an organic peroxide such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramentane hydroperoxide and the like, and a reducing agent such as a sugar-containing pyrophosphate formulation and a sulfoxylate formulation are combined. System initiators; persulfates such as potassium persulfate; peroxides such as benzoyl peroxide (BPO), lauroyl peroxide, tert-butyl peroxylaurate, and tert-butyl peroxymonocarbonate. These can be used alone or in combination of two or more. The amount of the polymerization initiator used is usually 0.1 to 1.5% by mass with respect to the total amount of the monomers.
The polymerization initiator can be added to the reaction system all at once or continuously.

Examples of the chain transfer agent include mercaptans such as octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, n-hexyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan, tert-tetradecyl mercaptan; and α-methylstyrene dimer. These can be used alone or in combination of two or more. The amount of the chain transfer agent used is usually 0.05 to 2.0% by mass with respect to the total amount of the monomers.
The chain transfer agent can be added to the reaction system all at once or continuously.

Examples of the emulsifier include anionic surfactants and nonionic surfactants. Anionic surfactants include higher alcohol sulfates; alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate; aliphatic sulfonates such as sodium lauryl sulfate; higher aliphatic carboxylates, aliphatic phosphates, etc. Is mentioned. Examples of nonionic surfactants include polyethylene glycol alkyl ester compounds and alkyl ether compounds. These can be used alone or in combination of two or more. The amount of the emulsifier used is usually 0.3 to 5.0% by mass with respect to the total amount of the monomers.

Emulsion polymerization can be performed under temperature conditions depending on the type of monomer, polymerization initiator, and the like. The latex obtained by this emulsion polymerization is usually purified by coagulating with a coagulant to make the resin component powdery, and then washing and drying. Examples of the coagulant include inorganic salts such as calcium chloride, magnesium sulfate, magnesium chloride, and sodium chloride; inorganic acids such as sulfuric acid and hydrochloric acid; organic acids such as acetic acid and lactic acid.

The graft ratio in the graft polymerization resins (g1) to (g5) is preferably 20 to 170%, more preferably 30 to 170%, and further preferably 40 to 150%. If this graft ratio is too low, the flexibility of the first resin layer obtained using the first thermoplastic resin composition may not be sufficient. On the other hand, if the graft ratio is too high, the viscosity of the first thermoplastic resin composition becomes high, and it may be difficult to reduce the thickness.

The graft ratio can be determined by the following formula.
Graft ratio (mass%) = {(ST) / T} × 100
In the above formula, S is obtained by adding 1 gram of graft polymerization resin to 20 ml of acetone (acetonitrile when the rubber component includes acrylic rubber), shaking at 25 ° C. for 2 hours with a shaker, The mass (gram) of insoluble matter obtained by centrifuging at 60 ° C. for 60 minutes with a centrifuge (rotation speed: 23,000 rpm) to separate the insoluble matter and the soluble matter, and T is 1 gram It is the mass (gram) of the rubber component contained in the graft polymerization resin. The mass of the rubber component can be obtained by a method of calculating from a polymerization prescription and a polymerization conversion rate, a method of obtaining from an infrared absorption spectrum (IR), and the like.

The graft ratio is determined by appropriately determining, for example, the type and amount of polymerization initiator used in the production of the graft polymerization resin, the type and amount of chain transfer agent, the monomer addition method and addition time, the polymerization temperature, etc. , Can be adjusted by selecting.

The intrinsic viscosity [η] (in methyl ethyl ketone, 30 ° C.) of the acetone-soluble component of the graft polymerization resin (when the rubber component contains acrylic rubber, acetonitrile-soluble component) is preferably 0.1 to 2.5 dl / g, more preferably 0.2 to 1.5 dl / g, still more preferably 0.25 to 1.2 dl / g. When the intrinsic viscosity is within this range, it is possible to form a first resin layer that is excellent in processability of the first thermoplastic resin composition and has high thickness accuracy.

Here, the intrinsic viscosity [η] can be obtained in the following manner.
When determining the graft ratio in the above graft polymerization resin, acetone-soluble matter recovered after centrifugation (if the rubbery polymer contains acrylic rubber, acetonitrile-soluble matter) is dissolved in methyl ethyl ketone and the concentration is different. Are prepared, and the reduced viscosity at each concentration is measured at 30 ° C. using an Ubbelohde viscometer to determine the intrinsic viscosity [η].

The intrinsic viscosity [η] is used when producing the graft polymerization resin, by adjusting the type and amount of polymerization initiator, chain transfer agent, emulsifier, solvent, etc., and further adjusting the polymerization time, polymerization temperature, etc. It can be controlled easily.

In order to make the first resin layer particularly excellent in adhesiveness with a filler part including an ethylene / vinyl acetate copolymer composition that embeds a solar cell element, the silicon-containing thermoplastic resin is used. The content of the silicon-containing structural unit derived from is preferably 0.05 to 20% by mass with respect to the total amount of the structural unit constituting the resin component (thermoplastic resin) contained in the first thermoplastic resin composition. More preferably, the content is 0.07 to 15% by mass, and still more preferably 0.1 to 10% by mass. When there is too much content of the said silicon-containing structural unit, an external appearance property may fall. The silicon-containing structural unit means a unit derived from a silicon-containing polymerizable unsaturated compound and a unit derived from an organosiloxane.

In order to make the first resin layer particularly excellent in heat resistance, the resin component (thermoplastic resin) contained in the first thermoplastic resin composition is a structural unit derived from a maleimide compound (hereinafter referred to as “ The structural unit (u1) ”is preferably included. This structural unit (u1) may be derived from any resin component. That is, the silicon-containing thermoplastic resin may contain the structural unit (u1), and other resin components may contain the structural unit (u1).
From the above viewpoint, the content of the structural unit (u1) is preferably 1 to 45 masses with respect to the total amount of the structural units constituting the resin component (thermoplastic resin) contained in the first thermoplastic resin composition. %, More preferably 5 to 40% by mass, still more preferably 10 to 35% by mass. When there is too much content of the said structural unit (u1), the flexibility of a 1st resin layer may fall.

The resin component having the structural unit (u1) is preferably a copolymer comprising a structural unit derived from an aromatic vinyl compound, a structural unit derived from a vinyl cyanide compound, and a structural unit (u1). . The content ratio of each structural unit is not particularly limited. Examples of this copolymer include acrylonitrile / styrene / N-phenylmaleimide copolymer.

Additives blended in the first thermoplastic resin composition used to form the first resin layer include antioxidants, ultraviolet absorbers, anti-aging agents, colorants, fluorescent whitening agents, weathering agents, and fillers. , Antistatic agents, flame retardants, antifogging agents, antibacterial agents, fungicides, antifouling agents, tackifiers and the like.

Examples of the antioxidant include hindered amine compounds, hydroquinone compounds, hindered phenol compounds, sulfur-containing compounds, and phosphorus-containing compounds. These can be used alone or in combination of two or more.
The content of the antioxidant is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of the thermoplastic resin including the silicon-containing thermoplastic resin.

Examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, and triazine compounds. These can be used alone or in combination of two or more.
The content of the ultraviolet absorber is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of the thermoplastic resin including the silicon-containing thermoplastic resin.

Examples of the anti-aging agent include naphthylamine compounds, diphenylamine compounds, p-phenylenediamine compounds, quinoline compounds, hydroquinone derivative compounds, monophenol compounds, bisphenol compounds, trisphenol compounds, polyphenol compounds, thiols. Examples thereof include bisphenol compounds, hindered phenol compounds, phosphite compounds, imidazole compounds, nickel dithiocarbamate salts, phosphoric compounds, and the like. These can be used alone or in combination of two or more.
The content of the anti-aging agent is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of the thermoplastic resin including the silicon-containing thermoplastic resin.

Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, butyl octyl phthalate, di- (2-ethylhexyl) phthalate, diisooctyl phthalate, and diisodecyl phthalate; dimethyl adipate , Diisobutyl adipate, di- (2-ethylhexyl) adipate, diisooctyl adipate, diisodecyl adipate, octyl decyl adipate, di- (2-ethylhexyl) azelate, diisooctyl azelate, diisobutyl azelate, dibutyl sebacate, di- Fatty acid esters such as (2-ethylhexyl) sebacate and diisooctyl sebacate; trimellitic acid isodecyl ester, trimellitic acid octyl Esters, trimellitic acid esters such as trimellitic acid n-octyl ester, trimellitic acid isononyl ester; di- (2-ethylhexyl) fumarate, diethylene glycol monooleate, glyceryl monoricinoleate, trilauryl phosphate, tristearyl phosphate, Examples include tri- (2-ethylhexyl) phosphate, epoxidized soybean oil and the like. These can be used alone or in combination of two or more.
The content of the plasticizer is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of the thermoplastic resin including the silicon-containing thermoplastic resin.

The first thermoplastic resin composition used for forming the first resin layer can be prepared by mixing raw material components such as a silicon-containing thermoplastic resin with a Henschel mixer and then melt-kneading. Examples of the apparatus used for melt kneading include a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader, and a continuous kneader.

When the back surface protective film for solar cells of the present invention is a single-layer film 1A as shown in FIG. 1, the production method of this film 1A is not particularly limited, and is an extrusion method (inflation film molding method, T-die casting). Film forming method), calender forming method, press forming method and the like.

Since the back surface protective film for a solar cell according to the present invention includes the first resin layer containing the silicon-containing thermoplastic resin, the surface of the first resin layer is bonded to the filler portion for embedding the solar cell element. Therefore, it is excellent in adhesiveness between the first resin layer and a filler part containing an ethylene / vinyl acetate copolymer composition or the like that embeds the solar cell element without providing an adhesive layer. Moreover, since this 1st resin layer has the said structure, when the back surface protection film for solar cells of this invention is a laminated | multilayer film, 1st resin layer and other resin which faces this 1st resin layer Excellent adhesion to layers.

The thickness of the back protective film for solar cells of the present invention is preferably 10 to 1,000 μm. The lower limit of the thickness is preferably 15 μm, more preferably 20 μm, and still more preferably 25 μm. The upper limit of the thickness is preferably 950 μm, more preferably 900 μm, and still more preferably 850 μm.

When the back surface protective film for solar cells of the present invention is a single layer type film (only the first resin layer), the lower limit of the thickness is preferably 10 μm from the viewpoint of adhesiveness with the filler part. The thickness is preferably 15 μm, more preferably 20 μm. The upper limit of the thickness is usually 1,000 μm, preferably 800 μm, more preferably 600 μm, and still more preferably 500 μm.

As described above, the back surface protective film for a solar cell of the present invention may be a film composed of only the first resin layer, that is, a single-layer film (see FIG. 1), the first resin layer 11, It may be a laminated film composed of another layer 15 bonded to the first resin layer 11 (see FIGS. 2 and 3).

The other layer 15 may be a layer that imparts at least one action of hydrolysis resistance, water resistance (moisture resistance), light reflectivity, and flame retardancy, depending on the purpose and application. The other layer 15 may be a single layer or may be composed of two or more layers.
The constituent material of the other layer 15 may be a resin composition (thermoplastic resin composition or cured resin composition), an inorganic compound, a metal, or the like.
A film 1 </ b> B in FIG. 2 that represents a laminated film includes a first resin layer 11 and another layer 15 bonded to the first resin layer 11. In FIG. 2, the other layer 15 represents another resin layer.
3 is a film in which the other layer 15 includes a metal layer 151 and a resin layer 153, and the first resin layer 11, the metal layer 151, and the resin layer 153 are sequentially joined.

When the back surface protective film for solar cells of the present invention is a laminated film 1B as shown in FIGS. 2 and 3, the thicknesses of the first resin layer 11 and the other layer 15 are preferably 5 to 600 μm, respectively. And 5 to 800 μm, more preferably 10 to 500 μm and 8 to 700 μm.

The back surface protective film for solar cells of this invention is illustrated below.
(1) When light having a wavelength of 400 to 1,400 nm is radiated to the surface of the first resin layer in the solar cell back surface protective film, a film having a reflectance of 50% or more with respect to the light (hereinafter referred to as “the present invention”). ("Film (I)")
(2) A film having a first resin layer having a transmittance of 60% or more for light having a wavelength of 800 to 1,400 nm and an absorbance of 60% or more for light having a wavelength of 400 to 700 nm (hereinafter referred to as “this” Invented film (II) ")

In the film (I) of the present invention, the reflectance with respect to light having a wavelength of 400 to 1,400 nm is such that the above light is applied to the surface of the first resin layer of the back protective film for solar cells (thickness 10 to 1,000 μm) of the present invention. Is measured by radiating. The reflectance is 50% or more, preferably 60% or more, more preferably 70% or more. The higher the reflectance, the more the light can be reflected toward the solar cell element disposed in the filler portion, and the photoelectric conversion efficiency can be improved.
In the present invention, “the reflectance with respect to light having a wavelength of 400 to 1,400 nm is 50% or more” means that the reflectance of light in the wavelength range from 400 nm to 1,400 nm is 400 nm or every 1,400 nm to 20 nm. Means that the average value calculated using each reflectance is 50% or more, and does not require that all the reflectances of light in the above-mentioned wavelength region are 50% or more.

In the film (I) of the present invention, when light having a wavelength of 400 to 1,400 nm is emitted only to the film constituting the first resin layer (thickness of 5 to 1,000 μm), the reflectance with respect to this light is preferably Is 50% or more, more preferably 60% or more, still more preferably 70% or more.

In the film (I) of the present invention, the L value (brightness) of the surface of the first resin layer is preferably 60 or more so that the reflectance for light with a wavelength of 400 to 1,400 nm is 50% or more. .
Therefore, the first thermoplastic resin composition constituting the first resin layer that satisfies the above properties is preferably a thermoplastic resin composition containing a silicon-containing thermoplastic resin and a white colorant.

Examples of the white colorant include titanium oxide, zinc oxide, calcium carbonate, barium sulfate, calcium sulfate, alumina, silica, 2PbCO ₃ .Pb (OH) ₂ , [ZnS + BaSO ₄ ], talc, and gypsum. Of these, titanium oxide is preferred. Moreover, these can be used individually by 1 type or in combination of 2 or more types. The content ratio of the white colorant in the first thermoplastic resin composition is based on 100 parts by mass of the total amount of the resin component (thermoplastic resin) including the silicon-containing thermoplastic resin from the viewpoint of reflectivity to the light. The amount is preferably 1 to 45 parts by mass, more preferably 3 to 40 parts by mass, and still more preferably 5 to 30 parts by mass. When there is too much content of this white type coloring agent, the flexibility of the film (I) of this invention may fall.
In addition, if it does not reduce the reflectance with respect to the said light to the surface of the 1st resin layer of the film (I) of this invention to less than 50%, according to the objective, a use, etc., further another colorant is added. Can be used. When using other colorants, the content is usually 5 parts by mass or less with respect to 100 parts by mass of the total amount of the resin component (thermoplastic resin) including the silicon-containing thermoplastic resin.

In the present invention, as shown in FIG. 2, a laminated film 1 </ b> B including a first resin layer 11 and another layer 15, and the light of only the film constituting the first resin layer 11. When the reflectance is less than 50% (when the first resin layer does not contain a white colorant or the like), by selecting the constituent material of the other layer 15, the wavelength 400 to 400 on the surface of the first resin layer is selected. It can be set as the film (I) of this invention whose reflectance with respect to 1,400 nm light is 50% or more, and, thereby, a photoelectric conversion efficiency can be improved.

In any case where the film (I) of the present invention is a monolayer film or a laminated film, the surface of the first resin layer has excellent reflectivity for light involved in photoelectric conversion. Therefore, when sunlight leaks from the gap between adjacent solar cell elements toward the back surface protective film for solar cell, the sunlight is reflected from the first resin layer, and the reflected light is reflected on the back surface of the solar cell element. It can be supplied and used for photoelectric conversion to improve power generation efficiency.

On the other hand, in the film (II) of the present invention, the transmittance with respect to light with a wavelength of 800 to 1,400 nm and the absorption with respect to light with a wavelength of 400 to 700 nm are on the surface of the first resin layer, that is, with a thickness of 10 to Each light is emitted only to the surface of a 1,000 μm single layer film (only the first resin layer) or to the film (thickness 5 to 1,000 μm) constituting the first resin layer in the laminated film. It is to be measured.
The transmittance is 60% or more, preferably 65% or more, and more preferably 70% or more. As the transmittance is higher, heat storage by light having a wavelength of 800 to 1,400 nm is suppressed in the first resin layer, so that heat storage of the filler portion bonded to the first resin layer is also suppressed. And the thermal storage of the solar cell module formed using this film (II) is suppressed, and electric power generation efficiency can be improved.
In the present invention, “the transmittance with respect to light having a wavelength of 800 to 1,400 nm is 60% or more” means that the transmittance of light in the wavelength region from 800 nm to 1,400 nm using the film constituting the first resin layer. Is measured every 800 nm or from 1,400 nm to 20 nm, and the average value calculated using each transmittance is 60% or more, and the light transmittance in the above wavelength range is all 60% or more. It is not required to be.

In the film (II) of the present invention, the light absorptance of the film constituting the first resin layer is 60% or more, preferably 70% or more, more preferably 80% or more. The higher the absorptance, the lower the brightness of the film constituting the first resin layer, and the dark first resin layer is formed. That is, this first resin layer forms a dark-colored solar cell back surface protective film. Thereby, when a solar cell is arrange | positioned on the roof etc. of a house, it is excellent in external appearance property.
In the present invention, “the transmittance with respect to light having a wavelength of 400 to 700 nm is 60% or more” means that the light absorptance in the wavelength region from 400 nm to 700 nm using the film constituting the first resin layer is 400 nm or Measured every 700 nm to 20 nm, meaning that the average value calculated using each absorptivity is 60% or more, and requires that all the absorptances of light in the above wavelength range are 60% or more is not.

In the film (II) of the present invention, in the film constituting the first resin layer, the transmittance for light with a wavelength of 800 to 1,400 nm is 60% or more, and the absorptance for light with a wavelength of 400 to 700 nm is 60% or more. Therefore, the film constituting the first resin layer preferably has a property of absorbing visible light and transmitting infrared light.
Accordingly, the first thermoplastic resin composition constituting the first resin layer satisfying the above properties includes a silicon-containing thermoplastic resin and a colorant having a property of absorbing visible light and transmitting infrared light (hereinafter referred to as “infrared rays”). It is preferable that the composition contains a “transparent colorant”.

The infrared transmissive colorant usually has a color other than white, and is preferably a dark color such as black, brown, dark blue, or dark green. By using a dark-colored infrared transmissive colorant, a solar cell module having an excellent dark-colored appearance can be provided without impairing the adhesion between the first resin layer and the filler part.

Examples of the infrared transmissive colorant include perylene pigments. As the perylene pigment, compounds represented by the following general formulas (3) to (5) can be used.

[Wherein, R ⁵ and R ⁶ are the same or different from each other, and are a butyl group, a phenylethyl group, a methoxyethyl group, or a 4-methoxyphenylmethyl group. ]

[In the formula, R ⁷ and R ⁸ are the same or different from each other, and include a phenylene group, a 3-methoxyphenylene group, a 4-methoxyphenylene group, a 4-ethoxyphenylene group, an alkylphenylene group having 1 to 3 carbon atoms, and a hydroxyphenylene group. Group, 4,6-dimethylphenylene group, 3,5-dimethylphenylene group, 3-chlorophenylene group, 4-chlorophenylene group, 5-chlorophenylene group, 3-bromophenylene group, 4-bromophenylene group, 5- Bromophenylene group, 3-fluorophenylene group, 4-fluorophenylene group, 5-fluorophenylene group, naphthylene group, naphthalenediyl group, pyridylene group, 2,3-pyridinediyl group, 3,4-pyridinediyl group, 4- Methyl-2,3-pyridinediyl group, 5-methyl-2,3-pyridinediyl group, 6-methyl Le-2,3-pyridinediyl group, 5-methyl-3,4-pyridinediyl group, 4-methoxy-2,3-pyridinediyl group, or a 4-chloro-2,3-pyridinediyl group. ]

In addition, as the perylene-based pigment, commercially available products such as “Paligen Black S 0084”, “Palogen Black L 0086”, “Lumogen Black FK4280”, “Lumogen Black FK4281” (all of which are trade names manufactured by BASF) are used. Can be used.
The infrared transmissive colorant can be used alone or in combination of two or more.

The content ratio of the infrared transmitting colorant in the first thermoplastic resin composition is 100 in terms of the total amount of the resin component (thermoplastic resin) containing the silicon-containing thermoplastic resin from the viewpoints of the transmittance and absorbability with respect to each light. The amount is preferably 5 parts by mass or less, more preferably 0.1 to 5 parts by mass with respect to parts by mass.
In addition, the 1st thermoplastic resin composition which comprises the 1st resin layer contained in the film (II) of this invention is according to the objective, a use, etc., unless the said permeability and absorptivity are reduced. Other colorants can be included. For example, a solar cell module having various appearances can be obtained by using a yellow pigment, a blue pigment, or the like as a colorant other than the infrared-transmitting colorant and using the following combinations.
[1] Brown coloration by combination of black-based infrared transmitting colorant and yellow pigment [2] Dark blue coloration by combination of black-based infrared transmitting colorant and blue pigment When other colorant is used, The content in the thermoplastic resin composition is usually 200 parts by mass or less, preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the infrared transmitting colorant.

Carbon black is known as a dark colorant. Since this carbon black absorbs light having a wavelength in the infrared region, the temperature of the film rises when sunlight leaks from the gap between adjacent solar cell elements toward the film (II) of the present invention. It is easy to increase the temperature of the filler part including the solar cell element, and may reduce the power generation efficiency, but by using the infrared transmissive colorant, the design property is not reduced without reducing the power generation efficiency. And excellent durability.

When the film (II) of the present invention is a single-layer film, that is, a film 1A (see FIG. 1) composed of a first resin layer, sunlight is reflected from the gap between adjacent solar cell elements to the back surface for solar cells. When leaking toward the protective film, the light having the wavelength of 800 to 1,400 nm is transmitted through the first resin layer, and heat storage due to this light is suppressed, so that the filler portion that adheres to the first resin layer Heat storage is suppressed. And the heat storage in the solar cell module formed using this film (II) is also suppressed, and the fall of power generation efficiency can be suppressed. Therefore, when this film (II) is separately combined with a member having light reflectivity to form a solar cell module, a part of sunlight leaked from the gap between adjacent solar cell elements and transmitted through the first resin layer. Can be reflected from the member, and the reflected light can be supplied to the back surface of the solar cell element while being transmitted through the first resin layer, and used for photoelectric conversion to improve power generation efficiency.
In addition, when the film (II) of the present invention is a laminated film as shown in FIG. 2, that is, a film 1 </ b> B including the first resin layer 11 and another layer 15, For example, by providing light reflectivity, part of sunlight leaking from the gap between adjacent solar cell elements and transmitted through the first resin layer is reflected from the member, and the reflected light is reflected from the first resin layer. While being transmitted, it can be supplied to the back surface of the solar cell element and used for photoelectric conversion to improve power generation efficiency.

When the film (II) of the present invention is a laminated film, the first resin layer has a transmittance of 60% or more for light with a wavelength of 800 to 1,400 nm and an absorptance for light with a wavelength of 400 to 700 nm of 60%. %, And when light having a wavelength of 800 to 1,400 nm is radiated to the surface of the first resin layer in the solar cell back surface protective film, the reflectance to this light is preferably 50% or more. . By providing this configuration, it has a dark color appearance and is excellent in appearance, and when sunlight hits the film, deformation of the constituent members including the film can be suppressed and power generation efficiency can be improved.
In order to obtain such a film (II), the other layer is preferably a resin layer, and this resin layer is preferably a white resin layer. And it is preferable that the composition which comprises this white resin layer contains a white colorant. When this composition is a thermoplastic resin composition or a cured resin composition, and these resin compositions are compositions containing a white colorant, the type of resin, the type of white colorant, and the content thereof The amount is not particularly limited.

When the back surface protective film for solar cells of the present invention is a laminated film including the first resin layer and other layers, from the viewpoint of optical properties such as productivity, flexibility, workability, and reflectivity. The other layer is a resin layer made of a thermoplastic resin composition (hereinafter referred to as “second thermoplastic resin composition”) containing a thermoplastic resin (hereinafter referred to as “second thermoplastic resin”). It is preferable to include.

The second thermoplastic resin is not particularly limited as long as it is a resin having thermoplasticity, and the thermoplastic resins exemplified in the description of the first thermoplastic resin can be used, one kind alone or two kinds. A combination of the above can be used. In the present invention, the second thermoplastic resin may be a copolymer resin obtained by polymerizing a monomer containing an aromatic vinyl compound in the presence of a rubbery polymer, or the copolymer resin and rubber. A rubber-reinforced aromatic vinyl resin comprising a mixture with an aromatic vinyl (co) polymer obtained by polymerizing a monomer containing an aromatic vinyl compound in the absence of a porous polymer, polyester Resins and olefin resins are preferred. When the second thermoplastic resin contains a rubber-reinforced aromatic vinyl resin, it is excellent in hydrolysis resistance, dimensional stability, impact resistance, and the like.

The second thermoplastic resin composition may be a composition composed only of the second thermoplastic resin, or may be a composition containing the second thermoplastic resin and an additive. The content of the additive can be the same as in the case of the first thermoplastic resin composition.

When the back surface protective film for solar cells of the present invention is a laminated film 1B as shown in FIG. 2, the manufacturing method of this film 1B is selected by the constituent materials of the other layers 15 and is not particularly limited. When the material is a thermoplastic resin composition, methods such as a co-extrusion method (T-die cast film molding method, etc.), a thermal fusion method, a dry lamination method, etc. can be mentioned, and a cured resin composition, an inorganic compound, a metal And the like, examples thereof include a heat fusion method, a vapor deposition method, and a sputtering method. In addition, a film obtained using the first thermoplastic resin composition and a film that constitutes the other layer 15 may be a polyurethane resin composition, an epoxy resin composition, an acrylic resin composition, or the like. You may join by the adhesive agent of this.
Examples of the film constituting the other layer 15 include a film made of a thermoplastic resin composition containing a polyester resin (hereinafter referred to as “polyester film”), a film for forming a water vapor barrier layer described later, and the like. . Examples of the polyester film include a polyethylene terephthalate film, a polyethylene naphthalate film, and a polybutylene terephthalate film. The other layer 15 may be formed using a commercially available product. For example, “Melinex 238” (trade name) manufactured by Teijin DuPont, “SR55” (trade name) manufactured by SKC, “Toray” Lumirror X10P, Lumirror ZV10, Lumirror X10S, Lumirror E20 (above, trade name) and the like. When the other layer 15 is formed using a polyester film, it can be set as the back surface protective film for solar cells excellent in scratch resistance.

When the back surface protective film for solar cells of the present invention is a laminated film, the other layer 15 can include a water vapor barrier layer. The other layer 15 can consist of only a water vapor | steam barrier layer, and also can consist of a water vapor | steam barrier layer and another resin layer.
The solar cell back surface protective film 1 </ b> C including the water vapor barrier layer is exemplified in FIG. 3, and includes a first resin layer 11, a water vapor barrier layer 15 including a metal layer 151 and a resin layer 153, and a first resin layer. 11 and the metal layer 151 are joined.

The water vapor barrier layer has a water vapor transmission rate (also referred to as “water vapor water vapor transmission rate”) measured under conditions of a temperature of 40 ° C. and a humidity of 90% RH in accordance with JIS K7129, preferably 3 g / (m ² · day) or less. More preferably, the layer has a performance of 1 g / (m ² · day) or less, and further preferably 0.7 g / (m ² · day) or less.
The water vapor barrier layer is preferably a layer made of an electrically insulating material.

The water vapor barrier layer may have a single layer structure or a multilayer structure made of one kind of material, or may have a single layer structure or a multilayer structure made of two or more kinds of materials. In the present invention, it is preferable that a vapor barrier layer is formed by using a vapor deposition film in which a film made of a metal and / or a metal oxide is formed on the surface as a material for forming a vapor barrier layer. Both the metal and the metal oxide may be a single substance or two or more kinds.
The water vapor barrier layer forming material may be a three-layer film in which a film made of a metal and / or a metal oxide is disposed between an upper resin layer and a lower resin layer.

Examples of the metal include aluminum.
Examples of the metal oxide include oxides of elements such as silicon, aluminum, magnesium, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, and yttrium. Of these, silicon oxide, aluminum oxide, and the like are particularly preferable from the viewpoint of water vapor barrier properties.
The film made of the metal and / or metal oxide may be formed by a method such as plating, vacuum deposition, ion plating, sputtering, plasma CVD, or microwave CVD. Two or more of these methods may be combined.

Examples of the resin layer in the vapor deposition film include polyester films such as polyethylene terephthalate film and polyethylene naphthalate; polyolefin films such as polyethylene and polypropylene; polyvinylidene chloride film, polyvinyl chloride film, fluororesin film, polysulfone film, polystyrene film, polyamide Examples thereof include a film, a polycarbonate film, a polyacrylonitrile film, and a polyimide film. The thickness of this resin film is preferably 5 to 50 μm, more preferably 8 to 20 μm.

The water vapor barrier layer may be formed using a commercially available product. For example, a film or sheet such as “Tech Barrier AX” manufactured by Mitsubishi Plastics, “GX Film” manufactured by Toppan Printing Co., Ltd., “Ecosia VE500” manufactured by Toyobo Co., Ltd. Can do.

The arrangement of the water vapor barrier layer facing the first resin layer is not particularly limited. When a vapor deposition film is used as the water vapor barrier layer forming material, a film made of a metal and / or a metal oxide may be bonded to the first resin layer, or the vapor deposition film may be on the outside (surface side). Good.

The thickness of the water vapor barrier layer is preferably 5 to 300 μm, more preferably 8 to 250 μm, and still more preferably 10 to 200 μm. If the water vapor barrier layer is too thin, the water vapor barrier property may be insufficient. If it is too thick, the flexibility as the back surface protective film for solar cell of the present invention may not be sufficient.

A method for producing a laminated film in which the other layer is a water vapor barrier layer is exemplified below.
(1) After producing a single layer type film as described above using the first thermoplastic resin composition, the surface of the single layer type film and the film for forming a water vapor barrier layer are thermally fused or Method of joining by dry lamination or adhesive (2) After producing a single layer type film as described above using the first thermoplastic resin composition, a metal and / or on the surface of the single layer type film Method for Forming Film Consisting of Metal Oxide (3) After producing a single layer type film as described above using the first thermoplastic resin composition, a metal and / or on the surface of this single layer type film Alternatively, a method of forming a film made of a metal oxide, and then bonding the film to another film using the thermoplastic resin composition by heat fusion, dry lamination, or an adhesive.

The solar cell module of the present invention is provided with the solar cell back surface protective film of the present invention. A schematic diagram of the solar cell module of the present invention is shown in FIG.
The solar cell module 2 in FIG. 4 includes a surface-side transparent protective member 21, a surface-side sealing film (surface-side filler) 23, a solar cell element 25, and a back surface side from the sunlight receiving surface side (upper side in the drawing). The sealing film (back surface side filler portion) 27 and the solar cell back surface protective film 1 of the present invention may be disposed in this order.

As the said surface side transparent protection member 21, what consists of a material excellent in water vapor | steam barrier property is preferable, and the transparent substrate which consists of glass, resin, etc. is used normally. In addition, although glass is excellent in transparency and weather resistance, since impact resistance is not sufficient and heavy, when using as a solar cell mounted on the roof of a house, it is preferable to use a weather resistant transparent resin. Examples of the transparent resin include a fluorine-based resin.
The thickness of the surface side transparent protective member 21 is usually about 1 to 5 mm when glass is used, and is usually about 0.1 to 5 mm when transparent resin is used.

The solar cell element 25 has a power generation function by receiving sunlight. As such a solar cell element, if it has a function as a photovoltaic power, it will not be specifically limited, A well-known thing can be used. For example, a crystalline silicon solar cell element such as a single crystal silicon type solar cell element or a polycrystalline silicon type solar cell element; an amorphous silicon solar cell element composed of a single bond type or a tandem structure type; gallium arsenide (GaAs) or indium phosphorus ( III-V compound semiconductor solar cell elements such as InP); II-VI compound semiconductor solar cell elements such as cadmium tellurium (CdTe) and copper indium selenide (CuInSe ₂ ). Of these, a crystalline silicon solar cell element is preferable, and a polycrystalline silicon solar cell element is particularly preferable. A thin film polycrystalline silicon solar cell element, a thin film microcrystalline silicon solar cell element, a hybrid element of a thin film crystalline silicon solar cell element and an amorphous silicon solar cell element, or the like can be used.

Although not shown in FIG. 3, the solar cell element 25 usually includes a wiring electrode and a take-out electrode. The wiring electrode has an action of collecting electrons generated in the plurality of solar cell elements by receiving sunlight, for example, a solar cell element on the surface side sealing film (surface side filler part) 21 side, It connects so that the solar cell element by the side of the back surface side sealing film (back surface side filler material part) 27 side may be connected. The take-out electrode has an action of taking out electrons collected by the wiring electrode or the like as a current.

The front-side sealing film (front-side filler part) 21 and the back-side sealing film (back-side filler part) 27 (hereinafter collectively referred to as “sealing film”) are usually the same as each other. Alternatively, after using a different sealing film forming material to form a sheet-shaped or film-shaped sealing film in advance, between the surface-side transparent protective member 21 and the solar cell back surface protective film 1, the solar cell element 25, etc. Formed by thermocompression bonding.
The thickness of each sealing film (filler part) is usually about 100 μm to 4 mm, preferably about 200 μm to 3 mm, more preferably about 300 μm to 2 mm. If the thickness is too thin, the solar cell element 25 may be damaged. On the other hand, if the thickness is too thick, the manufacturing cost increases, which is not preferable.

The sealing film forming material is usually a resin composition or a rubber composition. Examples of the resin contained in the composition include an olefin resin, an epoxy resin, and a polyvinyl butyral resin. Examples of the rubber include silicone rubber and hydrogenated conjugated diene rubber. Of these, olefin resins and hydrogenated conjugated diene rubbers are preferred.

Examples of olefin resins include olefins such as ethylene, propylene, butadiene, and isoprene, or polymers obtained by polymerizing diolefins, and ethylene and other monomers such as vinyl acetate and acrylate esters. Copolymers, ionomers and the like can be used. Specific examples include polyethylene, polypropylene, polymethylpentene, ethylene / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, ethylene / (meth) acrylic acid ester copolymer, ethylene / vinyl alcohol copolymer, chlorine. Examples thereof include chlorinated polyethylene and chlorinated polypropylene. Among these, an ethylene / vinyl acetate copolymer and an ethylene / (meth) acrylic acid ester copolymer are preferable, and an ethylene / vinyl acetate copolymer is particularly preferable.

Examples of hydrogenated conjugated diene rubber include hydrogenated styrene / butadiene rubber, styrene / ethylene butylene / olefin crystal block polymer, olefin crystal / ethylene butylene / olefin crystal block polymer, styrene / ethylene butylene / styrene block polymer, and the like. It is done. Preferably, a hydrogenated conjugated diene block copolymer having the following structure, that is, a polymer block A containing an aromatic vinyl compound unit; a conjugated diene compound having a 1,2-vinyl bond content exceeding 25 mol% Polymer block B obtained by hydrogenating at least 80 mol% of a double bond portion of a polymer containing units; Polymer double containing a conjugated diene compound unit having a 1,2-vinyl bond content of 25 mol% or less Polymer block C obtained by hydrogenating 80 mol% or more of the bonded portion; and a polymer block C obtained by hydrogenating 80 mol% or more of the double bond portion of the copolymer containing the aromatic vinyl compound unit and the conjugated diene compound unit. It is a block copolymer having at least two selected from the combined block D.

The sealing film-forming material may contain a crosslinking agent, a crosslinking aid, a silane coupling agent, an ultraviolet absorber, a hindered phenol-based or phosphite-based antioxidant, a hindered amine-based light stabilizer, a light as necessary. Additives such as diffusing agents, flame retardants, and anti-discoloring agents can be contained.
As described above, the material for forming the front surface side sealing film (front surface side filler portion) 23 and the material for forming the back surface side sealing film (back surface side filler portion) 27 are the same or different. However, the same is preferable from the viewpoint of adhesiveness.

The solar cell module of the present invention, for example, after arranging the surface side transparent protective member, the surface side sealing film, the solar cell element, the back surface side sealing film and the solar cell back surface protective film of the present invention in this order, These can be manufactured as one body by a lamination method or the like in which heat pressure bonding is performed while vacuum suction is performed.
The lamination temperature in this lamination method is usually about 100 ° C. to 250 ° C. from the viewpoint of adhesion of the solar cell back surface protective film of the present invention. The laminating time is usually about 3 to 30 minutes.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to such examples as long as the gist of the present invention is not exceeded. In the following, “part” and “%” are based on mass unless otherwise specified.

1. Evaluation method Measurement methods for various evaluation items are shown below.
1-1. Rubber content in thermoplastic resin From the composition at the time of raw material preparation for producing the thermoplastic resin composition constituting each resin layer, the total ratio of all rubber components to the total amount of thermoplastic resin in each resin layer Calculated.
1-2. N-Phenylmaleimide unit amount and silicon-containing structural unit amount It was calculated from the composition at the time of charging the raw materials for producing the thermoplastic resin composition constituting each resin layer.
1-3. Glass transition temperature (Tg)
Based on JIS K 7121, it was measured with a differential scanning calorimeter “DSC2910” (model name) manufactured by TA Instruments.

1-4. Peel strength The back protective film for solar cells was cut into strips (length 200 mm, width 15 mm, thickness described in the table) to obtain two evaluation films. A film “Ultra Pearl” (trade name, manufactured by Sanvic Co., Ltd.) having a length of 100 mm, a width of 15 mm and a thickness of 400 μm made of an ethylene / vinyl acetate copolymer is placed between two evaluation films and in a laminated state. I put it in the laminator. Thereafter, the upper and lower portions of the laminator were evacuated and preheated at 150 ° C. for 5 minutes. Next, the upper part was returned to atmospheric pressure and pressed for 15 minutes to obtain a sample for measuring peel strength.
In the obtained peel strength measurement sample, the peel strength was measured by peeling the T-shape from the portion where the evaluation film was not adhered to the EVA film. Moreover, the peeling state was evaluated. The peeled state was evaluated as “◯” when the EVA film was broken, and “X” when broken at the interface between the EVA film and the evaluation film part.

1-5. L value Back surface protection film for solar cells (50 mm x 50 mm, thickness is listed in the table), using a spectrophotometer "TCS-II" (model name) manufactured by Toyo Seiki Seisakusho Co., Ltd. L value of the 1st resin layer surface in a protective film was measured.

1-6. Reflectance (%) for light with a wavelength of 400 to 1,400 nm
Using a back protection film for solar cells (50 mm x 50 mm, thickness shown in the table) as a measurement sample, reflectivity was measured with an ultraviolet-visible near-infrared spectrophotometer "V-670" (model name) manufactured by JASCO Corporation did. That is, light was emitted to the surface of the first resin layer of the measurement sample, the reflectance in the wavelength region from 400 nm to 1,400 nm was measured every 20 nm, and the average value thereof was calculated.

1-7. Transmittance (%) for light with a wavelength of 800 to 1,400 nm
A first resin layer film (50 mm × 50 mm, thickness is listed in the table) obtained using a first thermoplastic resin composition containing an infrared transmitting colorant (perylene-based black pigment) is used as a measurement sample. The transmittance was measured with an ultraviolet-visible near-infrared spectrophotometer “V-670” (model name) manufactured by Bunko Co., Ltd. That is, light was emitted to the measurement sample, the transmittance in the wavelength region from 800 nm to 1,400 nm was measured every 20 nm, and the average value thereof was calculated.

1-8. Absorptivity (%) for light of wavelength 400-700nm
A first resin layer film (50 mm × 50 mm, thickness shown in the table) obtained using the first thermoplastic resin composition containing an infrared transmitting colorant (perylene-based black pigment) is used as a measurement sample. Transmittance and reflectance were measured with a spectrophotometer “V-670” (model name). That is, light was emitted to the measurement sample, the transmittance and reflectance in the wavelength range from 400 nm to 700 nm were measured every 20 nm, and the average value thereof was calculated. The absorptance was calculated by the following formula using the average value of transmittance and the average value of reflectance.
Absorptivity (%) = 100− {Transmittance (%) + Reflectance (%)}

1-9. Tensile strength retention (wet heat aging test)
The solar cell back surface protective film of a predetermined size was subjected to the following exposure test, and the tensile strength before and after exposure was measured according to JIS K7127, and the ratio was calculated.

<Exposure test>
The back protective film for solar cells was cut into strips (length: 200 mm, width: 15 mm) and left for 2,000 hours under conditions of a temperature of 85 ° C. and a humidity of 85% RH.

1-10. Dimensional stability The back surface protective film for a solar cell having a predetermined size was subjected to the following heating test, the length of the marked line before and after heating was measured, and the dimensional change rate was calculated based on the following formula.

From the calculated value, the dimensional stability was determined according to the following criteria.
○: Dimensional change rate is less than 1% Δ: Dimensional change rate is 1% or more and less than 2% ×: Dimensional change rate is 2% or more <Heating test>
The back surface protective film for solar cells was cut into a square shape (120 mm × 120 mm), and a square marked line of 100 mm × 100 mm was drawn at the center. The film was left in a constant temperature bath at a temperature of 120 ° C. for 30 minutes, then taken out and allowed to cool.

1-11. Photoelectric conversion efficiency improvement rate In a room adjusted to a temperature of 25 ° C. ± 2 ° C. and a humidity of 50 ± 5% RH, a cell is previously prepared using Peccell Technologies' Solar Simulator “PEC-11” (model name). A glass cell with a thickness of 3 mm is placed on the surface of a ¼ polycrystalline silicon cell whose photoelectric conversion efficiency is measured, and a back surface protective film for a solar cell is placed on the back surface. The silicon cell is sandwiched between the glass and the solar cell. EVA was introduced between the back surface protective films to seal the silicon cells, thereby producing solar cell modules. Then, in order to reduce the influence of temperature, the photoelectric conversion efficiency was measured immediately after the light irradiation. The photoelectric conversion efficiency improvement rate was calculated | required using the obtained photoelectric conversion efficiency and the photoelectric conversion efficiency of the cell single-piece | unit.
Photoelectric conversion efficiency improvement rate (%) = {(Photoelectric conversion efficiency of module−Photoelectric conversion efficiency of single cell) ÷ (Photoelectric conversion efficiency of single cell)} × 100

1-12. Water vapor barrier property Under the conditions of a temperature of 40 ° C. and a humidity of 90% RH, the water vapor permeability is measured according to JIS K7129B using a water vapor permeability measuring device “PERMATRAN W3 / 31” (model name) manufactured by MOCON. did. In addition, the surface of the side which is not the 1st resin layer was arrange | positioned as a permeation | transmission surface at the water vapor | steam side.

1-13. Scratch resistance The surface of the back surface protective film for solar cells that is not the first resin layer is subjected to 500 reciprocal frictions using a reciprocating friction tester manufactured by Tohken Seimitsu Kogyo Co., Ltd. under a vertical load of 500 g. It was. The subsequent surface was visually observed and judged according to the following criteria.
○: No scratch was observed Δ: Scratch was slightly observed ×: Scratch was clearly observed

2. Production raw materials for the back surface protective film for solar cells The raw material components used for the preparation of the thermoplastic resin composition are shown below.

2-1. Graft polymerization resin (A-1)
1.3 parts of p-vinylphenylmethyldimethoxysilane and 98.7 parts of octamethylcyclotetrasiloxane are mixed, and this is put into 300 parts of distilled water in which 2.0 parts of dodecylbenzenesulfonic acid is dissolved, and 3 parts by a homogenizer. The mixture was stirred and dispersed for emulsification. This emulsified dispersion was transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer, and heated at 90 ° C. for 6 hours while stirring. Subsequently, it was kept at 5 ° C. for 24 hours to complete the condensation, and a latex containing a polyorganosiloxane rubber (silicon-containing rubber) was obtained. The condensation rate was 93%. Thereafter, the latex was neutralized to pH 7 using an aqueous sodium carbonate solution. The obtained polyorganosiloxane rubber had a volume average particle size of 300 nm.
Next, a glass flask equipped with a stirrer and having an internal volume of 7 liters was charged with 100 parts of ion exchange water, 1.5 parts of potassium oleate, 0.01 parts of potassium hydroxide, 0.1 part of tert-dodecyl mercaptan, A batch polymerization component consisting of latex prepared at pH 7 containing 15 parts of organosiloxane rubber, 15 parts of styrene and 5 parts of acrylonitrile was added, and the temperature was raised while stirring. When the temperature reaches 45 ° C., the activity comprises 0.1 part of sodium ethylenediaminetetraacetate, 0.003 part of ferrous sulfate, 0.2 part of sodium formaldehyde sulfoxylate dihydrate and 15 parts of ion-exchanged water. Aqueous agent aqueous solution and 0.1 part of diisopropylbenzene hydroperoxide were added and polymerization was carried out for 1 hour.
Thereafter, 50 parts of ion-exchanged water, 1 part of potassium oleate, 0.02 part of potassium hydroxide, 0.1 part of tert-dodecyl mercaptan, 0.2 part of diisopropylbenzene hydroperoxide, 30 parts of styrene and An incremental polymerization component consisting of 10 parts of acrylonitrile was added continuously over 3 hours to continue the polymerization. After completion of the addition, stirring was further continued. After 1 hour, 0.2 part of 2,2′-methylenebis (4-ethyl-6-tert-butylphenol) was added to complete the polymerization, and a latex containing the graft polymerization resin (A-1) was obtained. Next, 1.5 parts of sulfuric acid is added to the latex to coagulate the resin component at 90 ° C., and then the resin component is washed with water, dehydrated and dried to obtain a powdered graft polymerization resin (A-1). Obtained. The glass transition temperature (Tg) was 108 ° C., the graft ratio was 84%, and the intrinsic viscosity [η] (in methyl ethyl ketone, 30 ° C.) was 0.60 dl / g.

2-2. Graft polymerization resin (A-2)
Accommodates latex with a solid content concentration of 40% containing 50 parts of acrylic rubber (gel content 90%) with a volume average particle diameter of 100 nm, obtained by emulsion polymerization of 99 parts of n-butyl acrylate and 1 part of allyl methacrylate. 1 part of sodium dodecylbenzenesulfonate and 150 parts of ion-exchanged water were added to the reactor and diluted. Thereafter, the inside of the reactor was replaced with nitrogen gas, and 0.02 part of disodium ethylenediaminetetraacetate, 0.005 part of ferrous sulfate and 0.3 part of sodium formaldehydesulfoxylate were added, and the mixture was stirred up to 60 ° C. The temperature rose.
On the other hand, in a separately prepared container, 1.0 part of terpinolene and 0.2 part of cumene hydroperoxide were dissolved in 50 parts of a mixture of 37.5 parts of styrene and 12.5 parts of acrylonitrile. To obtain a monomer composition.
Next, the monomer composition was polymerized at 70 ° C. over 5 hours while being added to the reactor at a constant flow rate to obtain a latex containing a graft polymerization resin (A-2). Magnesium sulfate was added to this latex to coagulate the resin component. Thereafter, the resin component was washed with water, dehydrated and dried to obtain a powdered graft polymerization resin (A-2). The glass transition temperature (Tg) was 108 ° C., the graft ratio was 93%, and the intrinsic viscosity [η] (in methyl ethyl ketone, 30 ° C.) was 0.30 dl / g.

2-3. Graft polymerization resin (A-3)
50 parts of acrylic rubber (gel content 90%) obtained by emulsion polymerization of 97.5 parts of n-butyl acrylate, 1 part of allyl methacrylate and 1.5 parts of vinylmethoxysilane 1 part of sodium dodecylbenzenesulfonate and 150 parts of ion-exchanged water were added to a reactor containing a latex containing 40% solid content and diluted. Thereafter, the inside of the reactor was replaced with nitrogen gas, and 0.02 part of disodium ethylenediaminetetraacetate, 0.005 part of ferrous sulfate and 0.3 part of sodium formaldehydesulfoxylate were added, and the mixture was stirred up to 60 ° C. The temperature rose.
On the other hand, in a separately prepared container, 1.0 part of terpinolene and 0.2 part of cumene hydroperoxide were dissolved in 50 parts of a mixture of 37.5 parts of styrene and 12.5 parts of acrylonitrile. To obtain a monomer composition.
Next, the monomer composition was polymerized at 70 ° C. over 5 hours while being added to the reactor at a constant flow rate to obtain a latex containing the graft polymerization resin (A-3). Magnesium sulfate was added to this latex to coagulate the resin component. Thereafter, the resin component was washed with water, dehydrated and dried to obtain a powdered graft polymerization resin (A-3). The glass transition temperature (Tg) was 108 ° C., the graft ratio was 93%, and the intrinsic viscosity [η] (in methyl ethyl ketone, 30 ° C.) was 0.30 dl / g.

2-4. Graft polymerization resin (A-4)
In a glass reaction vessel equipped with a stirrer, 75 parts of ion-exchanged water, 0.5 parts of potassium rosinate, 0.1 part of tert-dodecyl mercaptan, volume average particle size of 270 nm polybutadiene rubber (gel content: 90%) Latex having a solid content concentration of 57% containing 32 parts, Styrene-butadiene copolymer having a volume average particle size of 550 nm (styrene unit content 25%, gel content 50%) Latex having a solid content concentration of 68%, styrene 15 parts and 5 parts of acrylonitrile were put, and it heated up, stirring in nitrogen stream. When the internal temperature reached 45 ° C., an aqueous solution in which 0.2 parts of sodium pyrophosphate, 0.01 parts of ferrous sulfate heptahydrate and 0.2 parts of glucose were dissolved in 20 parts of ion-exchanged water was added. . Thereafter, 0.07 part of cumene hydroperoxide was added, polymerization was started at 70 ° C., and polymerization was performed for 1 hour.
Thereafter, 50 parts of ion-exchanged water, 0.7 part of potassium rosinate, 30 parts of styrene, 10 parts of acrylonitrile, 0.05 part of tert-dodecyl mercaptan and 0.01 part of cumene hydroperoxide are continuously added over 3 hours. The polymerization was continued. After the polymerization for 1 hour, 0.2 part of 2,2′-methylene-bis (4-ethylene-6-tert-butylphenol) was added to complete the polymerization to obtain a latex.
Next, magnesium sulfate was added to the latex to coagulate the resin component. Thereafter, the graft polymerization resin (A-4) was obtained by washing with water and drying. The graft ratio was 72%, and the intrinsic viscosity [η] of the acetone-soluble component was 0.47 dl / g. The glass transition temperature (Tg) was 108 ° C.

2-5. Acrylonitrile / styrene copolymer AS resin “SAN-H” (trade name) manufactured by Technopolymer Co., Ltd. was used. The glass transition temperature (Tg) is 108 ° C.

2-6. Acrylonitrile / styrene / N-phenylmaleimide copolymer Acrylonitrile / styrene / N-phenylmaleimide copolymer “Polyimilex PAS1460” (trade name) manufactured by Nippon Shokubai Co., Ltd. was used. The amount of N-phenylmaleimide units is 40%, the amount of styrene units is 51%, and the Mw in terms of polystyrene by GPC is 120,000. The glass transition temperature (Tg) is 173 ° C.

2-7. White colorant Titanium oxide “Taipeku CR-50-2” (trade name) manufactured by Ishihara Sangyo Co., Ltd. was used. The average primary particle size is 0.25 μm.

2-8. Infrared transmitting colorant A perylene-based black pigment “Lumogen BLACK FK4280” (trade name) manufactured by BASF was used.

2-9. Yellow colorant A quinophthalone yellow pigment “Pariotol Yellow K0961HD” (trade name) manufactured by BASF was used.

As the film for forming the other layers, the following water vapor barrier layer forming film and polyester film were used.

2-10. Water vapor barrier layer forming film (R-1)
A transparent vapor deposition film “Tech Barrier AX” (trade name) manufactured by Mitsubishi Plastics, Inc. was used. It is a transparent film having a silica vapor deposition film on one side of a PET film, and has a thickness of 12 μm and a water vapor transmission rate (JIS K7129) of 0.15 g / (m ² · day).
2-11. Water vapor barrier layer forming film (R-2)
An inorganic binary vapor barrier film “Ecosia VE500” (trade name) manufactured by Toyobo Co., Ltd. was used. It is a transparent film obtained by vapor-depositing (silica / alumina) on one side of a PET film, and has a thickness of 12 μm and a water vapor permeability of 0.5 g / (m ² · day).

2-12. Resin layer forming film (F-1)
A translucent PET film “Lumirror X10S” (trade name) manufactured by Toray Industries, Inc. was used. The thickness is 50 μm.
2-13. Resin layer forming film (F-2)
A milk white PET film “Melinex 238” (trade name) manufactured by Teijin DuPont was used. The thickness is 75 μm.

3. 3. Production and evaluation of back surface protective film for solar cell 3-1. Production and evaluation of back surface protective film for single-layer solar cell Example 1-1
Using Brabender, 40 parts of graft polymerization resin (A-1), 20 parts of acrylonitrile / styrene copolymer, 40 parts of acrylonitrile / styrene / N-phenylmaleimide copolymer and 20 parts of white colorant Were kneaded at 250 ° C. to obtain a first thermoplastic resin composition. Then, the back surface protective film for single layer type solar cells of thickness 35micrometer was obtained using T die. Various evaluation was performed about this back surface protective film for solar cells. The results are shown in Table 1.

Examples 1-2 to 1-5 and Comparative Examples 1-1 to 1-2
A back protective film for a single-layer solar cell was obtained in the same manner as in Example 1-1 except that the components listed in Table 1 were used at a predetermined ratio. Various evaluation was performed about this back surface protective film for solar cells. The results are also shown in Table 1.

As is apparent from Table 1, the back protective films for solar cells according to Comparative Examples 1-1 and 1-2 using a thermoplastic resin composition not containing a silicon-containing thermoplastic resin were made of an ethylene / vinyl acetate copolymer. In the adhesion to the film, the peel strength was as low as 12 to 15 N, and the adhesion was not sufficient.
On the other hand, the back surface protective films for solar cells according to Examples 1-1 to 1-5 using the first thermoplastic resin composition containing the silicon-containing thermoplastic resin have a high peel strength of 61 to 77 N and excellent adhesion. It was.

3-2.2 Production and Evaluation of Back Surface Protection Film for Layer Type Solar Cell Example 2-1
Each raw material component for forming the 1st resin layer and the 2nd resin layer of Table 2 was used at a barrel temperature of 270 ° C. using a twin screw extruder (model name “TEX44”, manufactured by Nippon Steel). By melt-kneading, two kinds of pellets of the first resin composition and the second resin composition were obtained.
Next, a multilayer film molding machine having two extruders having a die width of 1,400 mm and a lip interval of 1.5 mm and two screw diameters of 65 mm is used. Two resin compositions were supplied. Then, the molten resin was discharged from the T die at a melting temperature of 270 ° C. to obtain a two-layer soft film. After that, this two-layer soft film was cooled and solidified while being in surface contact with a cast roll whose surface temperature was controlled to 95 ° C. with an air knife, and a back surface protective film for laminated solar cells (white-white) having a thickness of 70 μm. White type) was obtained. The thicknesses of the first resin layer and the second resin layer are as shown in Table 2. The thickness of the film was determined by using a thickness gauge (model name “ID-C1112C”, manufactured by Mitutoyo Co., Ltd.), cutting the film after 1 hour from the start of film production, and at the center in the film width direction and at both ends from the center. Then, the thickness was measured at intervals of 10 mm (n = 107), and the average value was obtained. Measurement point values in the range of 20 mm from the edge of the film were removed from the average calculation.
Various evaluations were performed on the solar cell back surface protective film, and the results are also shown in Table 2.

Examples 2-2 to 2-5
After producing the first resin composition and the second resin composition using the raw material components for forming the first resin composition and the second resin composition described in Table 2, Example 2-1 and Similarly, a back surface protective film (white-white type) for a laminated solar cell was obtained. And about these back surface protection films for solar cells, various evaluation was performed and the result was written together in Table 2.

Examples 2-6 to 2-10
After producing the first resin composition and the second resin composition using the raw material components for forming the first resin composition and the second resin composition described in Table 3, Example 2-1 and Similarly, a back surface protective film for a laminated solar cell (black-white type) was obtained. And about these back surface protective films for solar cells, various evaluation was performed and the result was written together in Table 3.

Example 2-11
The raw material component for forming the 1st resin composition of Table 4 was knead | mixed at 250 degreeC using the Brabender, and the 1st resin composition was obtained. Then, the soft film which consists of this 1st resin composition was obtained using T die (150 micrometers in thickness).
Next, the resin layer forming film (F-1) was adhered to the surface of the soft film using a polyurethane-based adhesive to obtain a laminated solar cell back surface protective film. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 4.

Example 2-12
Using the first resin composition shown in Table 4 and the resin layer forming film (F-2), a laminated solar cell back surface protective film was obtained in the same manner as in Example 2-11. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 4.

Examples 2-13 to 2-14
Using the first resin composition shown in Table 5 and the resin layer forming film (F-1) or (F-2), the back surface of the laminated solar cell in the same manner as in Example 2-11 A protective film was obtained. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 5.

3-3. Production and Evaluation of Back Protective Film for Solar Cell Having Water Vapor Barrier Layer Example 3-1
The raw material component for forming the 1st resin layer of Table 6 was knead | mixed at 250 degreeC using the Brabender, and the 1st resin composition was obtained. Then, the soft film which consists of this 1st resin composition was obtained using T-die (120 micrometers in thickness).
Next, the water vapor barrier layer forming film (R-1) described in Table 6 is adhered to the surface of the soft film using a polyurethane-based adhesive so that the vapor deposition film becomes the outer surface, A solar cell back surface protective film having a water vapor barrier layer was obtained. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 6.

Example 3-2
Using the first resin composition described in Table 6, a flexible film was obtained in the same manner as in Example 3-1, and then the water vapor barrier layer forming film described in Table 6 was deposited on the outer surface. Thus, it was made to adhere using a polyurethane-based adhesive to obtain a back surface protective film for solar cells having a water vapor barrier layer. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 6.

Examples 3-3 to 3-4
Using the first resin composition described in Table 7, a soft film was obtained in the same manner as in Example 3-1, and then the water vapor barrier layer forming film described in Table 7 was used as the outer surface of the vapor deposition film. Thus, it was made to adhere using a polyurethane-based adhesive to obtain a back surface protective film for solar cells having a water vapor barrier layer. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 7.

Example 3-5
The raw material components for forming the first resin composition shown in Table 8 were kneaded at 250 ° C. using a Brabender to obtain a first resin composition. Then, the soft film which consists of this 1st resin composition was obtained using the T die (thickness 170 micrometers).
Next, the water vapor barrier layer-forming film (R-1) shown in Table 8 was adhered to the surface of the soft film using a polyurethane-based adhesive so that the deposited film was the outer surface. . Furthermore, the resin layer forming film (F-1) described in Table 8 is adhered to the surface of the vapor deposition film in the water vapor barrier layer using a polyurethane-based adhesive, and the solar cell having the water vapor barrier layer and the second resin layer is obtained. A battery back surface protective film was obtained. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 8.

Example 3-6
Using the materials shown in Table 8, a solar cell back surface protective film having a first resin layer, a water vapor barrier layer, and a second resin layer was obtained in the same manner as in Example 3-5. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 8.

Examples 3-7 to 3-8
Using the materials shown in Table 9, a back protective film for a solar cell having a first resin layer, a water vapor barrier layer, and a second resin layer was obtained in the same manner as in Example 3-5. And about this solar cell back surface protective film, various evaluation was performed and the result was written together in Table 9. FIG.

The back surface protective film for solar cells of the present invention includes a filler containing an ethylene / vinyl acetate copolymer composition or the like that embeds a solar cell element constituting a solar cell module in the resin layer (first resin layer). It is excellent in adhesiveness to parts, heat resistance and weather resistance, and as a whole film, it is excellent in light reflectivity or design, and of course a solar cell module constituting a solar cell used for a roof of a house This is useful as a member for protecting the back surface of a flexible solar cell module.

1, 1A, 1B and 1C: Back surface protection film for solar cell 11: First resin layer 15: Other layers (other resin layers, water vapor barrier layers, etc.)
151: Metal layer 153: Resin layer 2: Solar cell module 21: Front side transparent protective member 23: Front side sealing film 25: Solar cell element 27: Back side sealing film

Claims

A back protective film for solar cells, comprising a resin layer containing a silicon-containing thermoplastic resin.
The solar cell back surface protection according to claim 1, wherein when light having a wavelength of 400 to 1,400 nm is radiated to the surface of the resin layer in the solar cell back surface protective film, the reflectance to the light is 50% or more. the film.
The back protective film for solar cells according to claim 1 or 2, wherein the resin layer further contains a white colorant.
2. The back surface for a solar cell according to claim 1, wherein the resin layer has a transmittance of 60% or more for light having a wavelength of 800 to 1,400 nm and an absorbance of 60% or more for light having a wavelength of 400 to 700 nm. Protective film.
The solar cell back surface protective film according to claim 1, wherein the resin layer further contains an infrared transmitting colorant.
6. The solar cell according to claim 1, wherein the silicon-containing thermoplastic resin includes a graft polymerization resin obtained by polymerizing a monomer containing an aromatic vinyl compound in the presence of a silicon-containing rubber. Back protection film.
Furthermore, the back surface protective film for solar cells in any one of Claim 1 thru | or 6 provided with the other resin layer joined to the said resin layer.
The back surface protective film for a solar cell according to claim 7, wherein the other resin layer is a white resin layer.
The back surface protective film for solar cells according to any one of claims 1 to 8, wherein the thickness is 10 to 1,000 µm.
A solar cell module comprising the solar cell back surface protective film according to any one of claims 1 to 9.