JP5735225B2 - Laminated sheet for solar cell and solar cell module - Google Patents

Description

  The present invention relates to a laminated sheet for a solar cell used for protecting a solar cell element and a solar cell module including the laminated sheet.

  In recent years, as awareness of environmental issues such as global warming has increased, solar power generation, in particular, has high expectations in terms of cleanliness and non-pollution. The solar cell constitutes the central part of a photovoltaic power generation system that directly converts sunlight energy into electricity. In general, a plurality of solar cell elements (cells) are wired in series and in parallel as the structure, and various packaging is performed to protect the cells, thereby forming a unit. A unit incorporated in this package is called a solar cell module, and a surface to which sunlight is applied is generally covered with a transparent substrate (glass / translucent solar cell sheet; front sheet), and a thermoplastic (for example, ethylene- The gap is filled with a filler (sealing resin layer) made of a vinyl acetate copolymer), and the back surface is protected by a back surface sealing sheet (back sheet).

  Since these solar cell modules are mainly used outdoors, various characteristics are required for the structure and material structure thereof. The back sheet is also required to have sufficient durability, flame retardancy, dimensional stability, high mechanical strength, etc. in consideration of outdoor use. In addition, from the viewpoint of cleanliness and non-pollution, it is also required to reduce the environmental load. Furthermore, adhesion with a sealing resin layer and a junction box is also an important required characteristic. In particular, in order to effectively protect the power generation element in the sealing resin layer, the adhesiveness with the sealing resin layer is very important.

  As the back sheet, a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a cyclic olefin copolymer film (hereinafter sometimes referred to as “COC film”), a film made of polymethylmethacrylate and a COC film are laminated. The back sheet | seat which consists of a body, a polypropylene resin film, a fluorine resin film, etc. are proposed. (For example, see Patent Documents 1 to 8)

  On the other hand, an ethylene-vinyl acetate copolymer blended with an organic peroxide is widely used as the sealing resin layer (see, for example, Patent Document 9). The sealing resin layer must be flexible in the operating temperature range in order to protect the power generation element from impacts, etc., so that it can be carried at room temperature or stretched or slacked when attempting trimming or other processing. It has occurred and has the disadvantage of poor handling. Therefore, it is supplied in a form that is thickened or integrated with a process film.

  On the other hand, the structure (for example, refer patent documents 10-12) which laminated and integrated the sealing resin layer and the outer layer sheet | seat (back sheet | seat or front sheet | seat) is proposed. This improves handling when the sealing resin layer is used alone, and shortens the process compared to handling the sealing resin layer and the outer layer sheet (back sheet or front sheet) separately. Can be expected.

JP 2007-70430 A JP 2007-7885 A JP 2006-294780 A JP 2006-198922 A JP-A-8-306947 JP 2003-243679 A Japanese Patent No. 4177590 US registered patent No. 5593532 JP 58-60579 A JP-A-4-76230 JP 2000-91611 A JP 2000-174298 A

  However, backsheets such as those proposed in Patent Documents 1 to 8 are practical in terms of durability such as heat resistance (dimensional stability) and hydrolysis resistance, flame resistance, weather resistance, and sheet handling properties. Regarding various properties such as (workability) and adhesiveness with a sealing resin layer and a junction box, there is a problem that not all of them are necessarily satisfied.

Next, in Patent Documents 10 to 12, there is no special description or suggestion for increasing the adhesive strength between the sealing resin layer and the outer layer sheet, the adhesive strength is not sufficient, and peeling occurs. There was a problem.
In addition, for the outer layer sheet, as described above, heat resistance (dimensional stability), hydrolysis resistance, durability, flame resistance, weather resistance, sheet handling (workability), sealing resin layer and junction box There is a problem that not all of the properties such as adhesiveness are necessarily satisfied.

  That is, in the conventional technology, the sealing resin layer and the outer layer sheet having excellent durability, flame retardancy and dimensional stability and high adhesion to the sealing resin layer are laminated and integrated, thereby improving handling properties. An excellent laminated sheet for solar cells and a solar cell module including the laminated sheet have not been provided.

  Therefore, an object of the present invention is to improve handling properties by laminating and integrating a sealing resin layer and an outer sheet having excellent durability, flame retardancy, and dimensional stability and high adhesion to the sealing resin layer. An object is to provide an excellent laminated sheet for solar cell and a solar cell module including the laminated sheet.

As a result of intensive studies in view of the above problems, the present inventors have conceived the present invention described below and solved the problem. That is, the present invention
The following (I) layer and the following (II) layer are laminated and integrated, and the dimensional change rate of the following (II) layer when heated at 150 ° C. for 30 minutes in a dry air current is 3% or less. Battery laminated sheet.
(I) Sealing resin layer (II) Provided is a base material layer having a polyphenylene ether-based resin layer made of a resin composition containing polyphenylene ether as a main component on the surface in contact with the (I) layer.
Furthermore, this invention provides the solar cell module which uses the said laminated sheet for solar cells.

According to the present invention, the encapsulating resin layer and the outer layer sheet having excellent durability, flame retardancy and dimensional stability and high adhesion to the encapsulating resin layer are laminated and integrated so that the handling property is excellent. The laminated sheet for solar cells and the solar cell module comprising the same can be provided.
In addition, the laminated sheet for solar cell of the present invention includes a sealing resin layer and a layer having a polyphenylene ether-based resin layer, which are laminated in advance. The alignment process, the trimming process, and the like can be easily performed.

It is a schematic sectional drawing which shows an example of the solar cell module of this invention.

  Hereinafter, a laminated sheet for a solar cell as one example of an embodiment of the present invention and a solar cell module including the same will be described. However, the scope of the present invention is not limited to the embodiments described below.

  In the present specification, “main component” is intended to allow other components to be included within a range that does not interfere with the action and effect of the resin constituting each layer of the laminated sheet for solar cells of the present invention. It is. Further, this term does not limit the specific content, but it is 50% by mass or more, preferably 65% by mass or more, more preferably 80% by mass or more of the total components of the resin composition. It is a component occupying a range of mass% or less.

  In general, a “film” is a thin flat product whose thickness is extremely small compared to the length and width and whose maximum thickness is arbitrarily limited, and is usually supplied in the form of a roll. (JIS K6900) In general, the term “sheet” refers to a product that is thin according to the definition in JIS, and whose thickness is small for the length and width but flat. However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.

<(I) layer>
Of the layers constituting the solar cell laminate sheet of the present invention, the (I) layer is a sealing resin layer. Here, the layer (I) is not particularly limited, but is preferably composed of a resin composition containing a polyolefin resin or a modified polyolefin resin as a main component. Specific polyolefin resins and modified polyolefin resins are exemplified below, but these resins may be used alone or in combination of two or more. In addition, the layer (I) may be a single layer or a laminate of two or more layers as long as each layer is a layer composed of a resin composition mainly composed of a polyolefin resin or a modified polyolefin resin.

[Polyolefin resin]
The kind of the polyolefin resin is not particularly limited, but is preferably at least one resin selected from the group consisting of a polyethylene polymer, a polypropylene polymer, and a cyclic olefin polymer.

[Polyethylene polymer]
The type of the polyethylene polymer is not particularly limited, and specifically, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene (ethylene-α-olefin copolymer), medium density polyethylene. , High density polyethylene, or ultra high density polyethylene. Among these, linear low density polyethylene (ethylene-α-olefin copolymer) has low crystallinity and excellent transparency and flexibility, so that it inhibits the power generation characteristics of the solar cell element and causes excessive stress to the solar cell element. In addition, it is preferable because it is difficult to cause defects such as damage.

  The ethylene-α-olefin copolymer may be a random copolymer or a block copolymer. Although it does not specifically limit as a kind of alpha olefin copolymerized with ethylene, Usually, a C3-C20 alpha olefin is used suitably. Examples of the α-olefin copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 3-methyl-butene. -1,4-methyl-pentene-1 and the like. In the present invention, propylene, 1-butene, 1-hexene, and 1-octene are preferably used as the α-olefin copolymerized with ethylene from the viewpoints of industrial availability, various characteristics, and economical efficiency. It is done. The α-olefin copolymerized with ethylene may be used alone or in combination of two or more.

  Further, the content of the α-olefin copolymerized with ethylene is not particularly limited, but is usually 2 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, and usually It is 40 mol% or less, preferably 30 mol% or less, more preferably 25 mol% or less. Within this range, the crystallinity is reduced by the copolymerization component, so that the transparency is improved and problems such as blocking of the raw material pellets are less likely to occur. In addition, the kind and content of the α-olefin copolymerized with ethylene can be qualitatively and quantitatively analyzed by a well-known method, for example, a nuclear magnetic resonance (NMR) measuring apparatus or other instrumental analyzer.

  The method for producing the polyethylene polymer is not particularly limited, and a known polymerization method using a known olefin polymerization catalyst can be employed. For example, slurry polymerization method, solution polymerization method, bulk polymerization method, gas phase polymerization method using multi-site catalyst represented by Ziegler-Natta type catalyst, single site catalyst represented by metallocene catalyst and post metallocene catalyst And a bulk polymerization method using a radical initiator. The ethylene-α-olefin copolymer used as the sealing resin layer is preferably a relatively soft resin, and has a low molecular weight component from the viewpoint of ease of granulation after polymerization and prevention of blocking of raw material pellets. A polymerization method using a single site catalyst capable of polymerizing a raw material with a small molecular weight distribution and a small molecular weight distribution is suitable.

  Specific examples of the polyethylene-based polymer used in the present invention include trade names “Hizex”, “Neozex”, “Ultzex”, and Nippon Polyethylene Corporation (manufactured by Prime Polymer Co., Ltd.). Product names “Novatec HD”, “Novatech LD”, “Novatech LL”, product names “Engage”, “Affinity”, “Infuse” manufactured by Dow Chemical Co., Ltd. ) ”, Trade name“ TAFMER A ”,“ TAFMER P ”manufactured by Mitsui Chemicals, Inc., trade name“ Kernel ”manufactured by Nippon Polyethylene Co., Ltd., etc. Can do.

[Polypropylene polymer]
The type of the polypropylene polymer is not particularly limited, and specific examples include a propylene homopolymer, a propylene copolymer, a reactor type polypropylene thermoplastic elastomer, and a mixture thereof. It is done.
As a copolymer of propylene, a random copolymer (random polypropylene) of propylene and ethylene or other α-olefin, a block copolymer (block polypropylene), a block copolymer or a graft copolymer containing a rubber component Etc. The other α-olefin copolymerizable with propylene is preferably one having 4 to 12 carbon atoms, such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4 -Methyl-1-pentene, 1-decene, etc. are mentioned, The 1 type (s) or 2 or more types of mixture is used.

  Further, the content of the α-olefin copolymerized with propylene is not particularly limited, but is usually 2 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, and usually It is 40 mol% or less, preferably 30 mol% or less, more preferably 25 mol% or less. Within this range, the crystallinity is reduced by the copolymerization component, so that the transparency is improved and problems such as blocking of the raw material pellets are less likely to occur. In addition, the kind and content of the α-olefin copolymerized with propylene can be qualitatively and quantitatively analyzed by a well-known method, for example, a nuclear magnetic resonance (NMR) measuring device or other instrumental analyzer.

  The production method of the polypropylene polymer is not particularly limited, and a known polymerization method using a known olefin polymerization catalyst can be employed. For example, slurry polymerization method, solution polymerization method, bulk polymerization method, gas phase polymerization method using multi-site catalyst represented by Ziegler-Natta type catalyst, single site catalyst represented by metallocene catalyst and post metallocene catalyst And a bulk polymerization method using a radical initiator. The propylene-α-olefin copolymer used as the sealing resin layer is preferably a relatively soft resin, and has a low molecular weight component from the viewpoint of ease of granulation after pelletization and prevention of blocking of raw material pellets. A polymerization method using a single site catalyst capable of polymerizing a raw material with a small molecular weight distribution and a small molecular weight distribution is suitable.

  As specific examples of polypropylene used in the present invention, trade names “Novatech PP” and “Wintech” manufactured by Nippon Polypro Co., Ltd., trade names “Prime Polypro” and “Prime TPO” manufactured by Prime Polymer Co., Ltd., A trade name “Noblen” manufactured by Sumitomo Chemical Co., Ltd. can be exemplified.

[Cyclic olefin polymer]
The type of the cyclic olefin polymer is not particularly limited, and specifically, a cyclic olefin polymer obtained by ring-opening polymerization of one or more cyclic olefins, a hydride thereof, and a linear chain. And a block copolymer of a linear α-olefin and a cyclic olefin, and a random copolymer of a linear α-olefin and a cyclic olefin.

  The type of the cyclic olefin constituting the cyclic olefin polymer is not particularly limited, but bicyclohept-2-ene (2-norbornene) and its derivatives such as norbornene, 6-methylnorbornene, 6-ethyl. Norbornene, 6-n-butylnorbornene, 5-propylnorbornene, 1-methylnorbornene, 7-methylnorbornene, 5,6-dimethylnorbornene, 5-phenylnorbornene, 5-benzylnorbornene, tetracyclo-3-dodecene and its derivatives As, for example, 8-methyltetracyclo-3-dodecene, 8-ethyltetracyclo-3-dodecene, 8-hexyltetracyclo-3-dodecene, 10-dimethyltetracyclo-3-dodecene, 5,10-dimethyl Tetracyclo-3-dodecene Etc., and the like. In the present invention, norbornene, tetracyclododecene, and the like are preferably used from the viewpoints of industrial availability, various characteristics, economy, and the like.

  Although it does not specifically limit as a kind of linear alpha olefin copolymerized with the said cyclic olefin, Usually, a C2-C20 linear alpha olefin is used suitably. Examples of the linear α-olefin copolymerized with the cyclic olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene. Etc. In the present invention, ethylene is preferably used as the linear α-olefin copolymerized with the cyclic olefin from the viewpoints of industrial availability, various properties, economy, and the like. The linear α-olefin copolymerized with the cyclic olefin may be used alone or in combination of two or more.

  Further, the content of the cyclic olefin copolymerized with the linear α-olefin is not particularly limited, but is usually 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more. And, it is usually 70 mol% or less, preferably 60 mol% or less, more preferably 50 mol% or less. When the content of the cyclic olefin is increased, the heat resistance, the barrier property and the transparency can be improved, and when the content is decreased, the flexibility is improved, which is preferable. If the content of the cyclic olefin is within this range, it is preferable because the crystallinity is reduced by the copolymerization component, transparency is exhibited, and problems such as blocking of raw material pellets hardly occur. In addition, the kind and content of the cyclic olefin copolymerized with the linear α-olefin can be qualitatively and quantitatively analyzed by a well-known method, for example, a nuclear magnetic resonance (NMR) measuring device or other instrumental analyzer.

  Examples of the cyclic olefin polymer used in the present invention include, for example, JP-A-60-168708, JP-A-612012016, JP-A-61-115912, and JP-A-61-115916. Manufactured according to known methods described in JP-A-61-271308, JP-A-61-272216, JP-A-62-252406, JP-A-62-2252407, etc. be able to.

  Specific examples of the cyclic olefin-based polymer used in the present invention include trade names “APEL” manufactured by Mitsui Chemicals, Inc., trade names “TOPAS” manufactured by Topas Advanced Polymers, Examples include trade names “ZEONOR” and “ZEONEX” manufactured by Nippon Zeon Co., Ltd.

[Modified polyolefin resin]
The type of the modified polyolefin resin constituting the layer (I) in the present invention is not particularly limited, but EVA (ethylene-vinyl acetate copolymer), EVOH (ethylene-vinyl alcohol copolymer), E- MMA (ethylene-methyl methacrylate copolymer), E-EAA (ethylene-ethyl acrylate copolymer), E-GMA (ethylene-glycidyl methacrylate copolymer), ionomer resin (ionic crosslinkable ethylene-methacrylic acid copolymer) It is preferably at least one resin selected from the group consisting of a polymer, an ionically crosslinkable ethylene-acrylic acid copolymer), a silane crosslinkable polyolefin, and a maleic anhydride graft copolymer.

  As described above, the laminated sheet for a solar cell of the present invention is a (I) layer that is a sealing resin layer, and a polyphenylene ether-based resin layer comprising a resin composition containing polyphenylene ether as a main component on the surface in contact with the (I) layer. The (II) layer having a layer is laminated and integrated. When the layer (I) is composed of the modified polyolefin resin as a main component, the adhesiveness with the polyphenylene ether resin layer is improved due to the presence of the modified group.

  The content of various monomers that modify the modified polyolefin resin is not particularly limited, but is usually 0.5 mol% or more, preferably 1 mol% or more, more preferably 2 mol% or more. And, it is usually 40 mol% or less, preferably 30 mol% or less, more preferably 25 mol% or less. Within this range, the crystallinity is reduced by the copolymerization component, so that the transparency is improved and problems such as blocking of the raw material pellets are less likely to occur. The types and contents of various monomers that modify the modified polyolefin resin can be qualitatively and quantitatively analyzed by a known method, for example, a nuclear magnetic resonance (NMR) measuring device or other instrumental analyzer.

  The method for producing the modified polyolefin resin used in the present invention is not particularly limited. A known olefin polymerization catalyst is used except for the ionomer resin, silane crosslinkable polyolefin, and maleic anhydride graft copolymer shown below. Known polymerization methods used, for example, slurry polymerization method, solution polymerization method, bulk polymerization method, gas phase polymerization method using multi-site catalyst represented by Ziegler-Natta type catalyst and single site catalyst represented by metallocene catalyst Or a bulk polymerization method using a radical initiator.

  The ionomer resin contains at least a part of an unsaturated carboxylic acid component of a copolymer comprising ethylene, an unsaturated carboxylic acid, and other unsaturated compounds as optional components, at least one of a metal ion and an organic amine. It can be obtained by summing. The ionomer resin can also be obtained by saponifying at least a part of an unsaturated carboxylic acid ester component of a copolymer comprising ethylene, an unsaturated carboxylic acid ester, and other unsaturated compounds as optional components. .

  The silane crosslinkable polyolefin can be obtained by melt-mixing a polyolefin-based resin, a silane coupling agent described below, and a radical generator described below at a high temperature and graft polymerization.

  The maleic anhydride graft copolymer can be obtained by melt-mixing a polyolefin resin, maleic anhydride, and a radical generator described later at a high temperature and graft polymerization.

  Specific examples of the modified polyolefin resin used in the present invention include EVA (ethylene-vinyl acetate copolymer), trade name “Novatech EVA” manufactured by Nippon Polyethylene Co., Ltd., Mitsui DuPont Polychemical Co., Ltd. Product name “EVAFLEX” manufactured by Nihon Unicar Co., Ltd. “NUC” series, EVOH (ethylene-vinyl alcohol copolymer) as the product name “Soarnol” manufactured by Nippon Synthetic Chemical Co., Ltd., The product name “EVAL” manufactured by Kuraray Co., Ltd. and E-MMA (ethylene-methyl methacrylate copolymer) are trade names “ACRIFT” manufactured by Sumitomo Chemical Co., Ltd., and E-EAA (ethylene-ethyl acrylate copolymer). The product name “REXPEARL EEA” manufactured by Nippon Polyethylene Co., Ltd., E-GMA As the ethylene-glycidyl methacrylate copolymer), the trade name “BONDFAST” manufactured by Sumitomo Chemical Co., Ltd., and as the ionomer resin, the product name “HIMILAN” manufactured by Mitsui DuPont Polychemical Co., Ltd., silane crosslinking Examples of the functional polyolefin include trade name “Linklon” manufactured by Mitsubishi Chemical Corporation, and examples of the maleic anhydride graft copolymer include “Admer” manufactured by Mitsui Chemicals, Inc.

  The melt flow rate (MFR) of the polyolefin resin and the modified polyolefin resin is not particularly limited. For example, in the case of polyethylene, MFR (JIS K7210, temperature: 190 ° C., load: 21.18N) Preferably it is 0.5 g / 10 min or more, more preferably 2 g / 10 min or more, still more preferably 3 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 25 g / 10 min or less, still more preferably 20 g / 10 min. The following are used. Here, the MFR may be selected in consideration of molding processability at the time of molding the sheet, adhesiveness at the time of sealing the solar cell element (cell), wraparound condition, and the like. For example, when calendering a sheet, the MFR is preferably relatively low, specifically 0.5 g / 10 min or more and 5 g / 10 min or less from the handling property when the sheet is peeled off from the forming roll. In the case of extrusion molding using a T-die, the MFR is preferably 2 g / 10 min or more, more preferably 3 g / 10 min or more, and preferably 30 g from the viewpoint of reducing the extrusion load and increasing the extrusion amount. / 10 min or less, more preferably 20 g / 10 min or less may be used. Furthermore, from the viewpoint of adhesion and ease of wraparound when sealing a solar cell element (cell), the MFR is preferably 2 g / 10 min, more preferably 3 g / 10 min or more, and preferably 30 g / What is used is 10 min or less, more preferably 20 g / 10 min or less.

In the resin composition constituting the (I) layer in the present invention, various physical properties (flexibility, heat resistance, transparency, adhesiveness, etc.), molding processability, economical efficiency, etc. are within the scope of the present invention. Resin other than the above-described polyolefin resin and modified polyolefin resin can be mixed for the purpose of further improving the property.
Examples of the resin include other polyolefin resins and various elastomers (olefin-based, styrene-based, etc.), modified with polar groups such as carboxyl group, amino group, imide group, hydroxyl group, epoxy group, oxazoline group, and thiol group. Resin and tackifying resin.

  Examples of the tackifying resin include petroleum resins, terpene resins, coumarone-indene resins, rosin resins, and hydrogenated derivatives thereof. Specifically, the petroleum resin includes cyclopentadiene or an alicyclic petroleum resin derived from a dimer thereof and an aromatic petroleum resin derived from a C9 component, and the terpene resin includes a terpene resin derived from β-pinene and a terpene resin. Examples of the phenol resin include rosin resins such as gum rosin and wood rosin, and esterified rosin resins modified with glycerin, pentaerythritol, and the like. The tackifying resin can be obtained with various softening temperatures mainly depending on the molecular weight, but the compatibility, bleed over time and color tone when mixed with the polyolefin resin and modified polyolefin resin component described above. In view of heat stability, the softening temperature is preferably 100 or higher, more preferably 120 ° C. or higher, and preferably 150 ° C. or lower, more preferably 140 ° C. or lower. preferable. When a resin other than the polyolefin-based resin or modified polyolefin-based resin described above is mixed, usually, when the resin composition constituting the (I) layer is 100% by mass, 20% by mass or less is preferable, and 10% by mass or less is preferable. Is more preferable.

  Moreover, various additives can be added to the resin composition constituting the (I) layer in the present invention, if necessary. Examples of the additive include radical generators (crosslinking agents / crosslinking aids), silane coupling agents, antioxidants, ultraviolet absorbers, weathering stabilizers, light diffusing agents, nucleating agents, pigments (for example, white pigments) ), Flame retardants, discoloration inhibitors and the like. In the present invention, it is preferable that at least one additive selected from a radical generator, a silane coupling agent, an antioxidant, an ultraviolet absorber, and a weathering stabilizer is added for reasons described later.

[Radical generator]
The radical generator (crosslinking agent / crosslinking aid) has a crosslinked structure for the purpose of improving heat resistance or increasing mechanical strength when a polyolefin resin or a modified polyolefin resin is used for the sealing resin layer. Useful for. The radical generator is not particularly limited, and examples thereof include organic peroxides, azo compounds such as azobisisobutyronitrile (AIBN) and polymer azo compounds, and organometallic compounds such as allyltin and triethylborane. . Among them, organic peroxides that generate radicals at 100 ° C. or higher and have a decomposition temperature of 70 ° C. or higher at a half-life of 10 hours are preferably used from the viewpoint of reaction rate and safety during compounding. The
Examples of such radical generators include 2,5-dimethylhexane; 2,5-dihydroperoxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; 3-di- t-butyl peroxide; t-dicumyl peroxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne; dicumyl peroxide; α, α'-bis (t-butylperoxy) Isopropyl) benzene; n-butyl-4,4-bis (t-butylperoxy) butane; 2,2-bis (t-butylperoxy) butane; 1,1-bis (t-butylperoxy) cyclohexane; 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane; t-butylperoxybenzoate; benzoyl peroxide, etc. are preferred It is possible to have. The amount of these radical generators added is to suppress the increase in resin pressure and the generation of foreign matter such as gels and fish eyes, and to prevent problems such as bleed out from molded products. The amount of the resin composition constituting the (I) layer in the present invention is preferably 5% by mass or less, more preferably 3% by mass or less, based on 100% by mass. Moreover, in order to advance a crosslinking reaction efficiently, it is preferable that it is 0.25 mass% or more, It is more preferable that it is 0.5 mass% or more, It is further more preferable that it is 0.75 mass% or more. .

[Silane coupling agent]
Silane coupling agents are useful for improving the adhesion to protective materials for sealing resin layers (glass, resin front sheets, back sheets, etc.) and solar cell elements. And compounds having a hydrolyzable group such as an alkoxy group in addition to an unsaturated group such as an acryloxy group and a methacryloxy group, an amino group, and an epoxy group. Specific examples of the silane coupling agent include N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxy. Examples include silane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like. In the present invention, γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane are preferably used because of good adhesiveness and little discoloration such as yellowing. The amount of the silane coupling agent added is 100% by mass of the resin composition constituting the layer (I) in the present invention in order to suppress an increase in the resin pressure and the generation of foreign substances such as gels and fish eyes. In order to suppress problems such as bleed out from the molded product, the content is preferably 5% by mass or less, and more preferably 3% by mass or less. Moreover, in order to express adhesiveness, it is preferable that it is 0.1 mass% or more, and it is more preferable that it is 0.2 mass% or more.
In addition, similar to the silane coupling agent, a coupling agent such as an organic titanate compound can be effectively used.

As described above, the laminated sheet for a solar cell of the present invention is a (I) layer that is a sealing resin layer, and a polyphenylene ether-based resin layer comprising a resin composition containing polyphenylene ether as a main component on the surface in contact with the (I) layer. The (II) layer having a layer is laminated and integrated. When the radical generator (crosslinking agent, crosslinking aid) or silane coupling agent is contained in the layer (I), the adhesion to the polyphenylene ether resin layer is particularly good.
Although the mechanism of particularly good adhesion is not clear, the active hydrogen and radical generator contained in the polyphenylene ether resin, which is the main component of the polyphenylene ether resin layer, and the reactive group (alkoxysilane) of the silane coupling agent It is presumed that the adhesiveness of both layers is remarkably improved by the reaction with the group) to form a crosslinked structure.

[Antioxidant]
As the antioxidant, various commercially available products can be applied, and various types such as monophenol type, bisphenol type, polymer type phenol type, sulfur type and phosphite type can be exemplified. Examples of monophenols include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and the like. Examples of the bisphenol include 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4 '-Thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 3,9-bis [{1,1-dimethyl- 2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl} 2,4,9,10-tetraoxaspiro] 5,5-undecane.

  Examples of the high molecular phenolic group include 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3 , 5-di-tert-butyl-4-bidoxybenzyl) benzene, tetrakis- {methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate} methane, bis { (3,3′-bis-4′-hydroxy-3′-tert-butylphenyl) butyric acid} glycol ester, 1,3,5-tris (3 ′, 5′-di-tert-butyl-4 '-Hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione, triphenol (vitamin E) and the like can be mentioned.

  Examples of sulfur-based compounds include dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiopropionate.

  The phosphite system includes triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, Crick neopentanetetrayl bis (octadecyl phosphite), tris (mono and / or di) phenyl phosphite, diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10 -Dihydro-9-oxa-10-phosphine Phenanthrene, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-methylphenyl) phosphite, 2,2- And methylene bis (4,6-tert-butylphenyl) octyl phosphite. In the present invention, phenol-based and phosphite-based antioxidants are preferably used in view of the effects of antioxidants, thermal stability, economy, etc., and using both in combination as an antioxidant with respect to the added amount It is more preferable because the effect can be enhanced. The addition amount of the antioxidant is usually 0.1% by mass or more, preferably 0.2% by mass or more with respect to 100% by mass of the resin composition constituting the layer (I) in the present invention. It is preferable to add in a range of not more than mass%, preferably not more than 0.5 mass%.

[Ultraviolet absorber]
As the ultraviolet absorber, various commercially available products can be applied, and various types such as benzophenone, benzotriazole, triazine, and salicylic acid ester can be exemplified. Examples of the benzophenone-based UV absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n. -Dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2, , 4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, etc. But it can.

  The benzotriazole ultraviolet absorber is a hydroxyphenyl-substituted benzotriazole compound, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) Benzotriazole, 2- (2-hydroxy-3,5-dimethylphenyl) benzotriazole, 2- (2-methyl-4-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3-methyl-5-t- Butylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, etc. be able to. Examples of triazine ultraviolet absorbers include 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2- ( And 4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyloxy) phenol. Examples of salicylic acid esters include phenyl salicylate and p-octylphenyl salicylate. The addition amount of the ultraviolet absorber is usually 0.01% by mass or more, preferably 0.05% by mass or more with respect to 100% by mass of the resin composition constituting the layer (I) in the present invention, and 2 It is preferable to add in the range of 0.0 mass% or less, preferably 0.5 mass% or less.

[Anti-stabilizer]
A hindered amine light stabilizer is suitably used as a weather stabilizer that imparts weather resistance in addition to the above ultraviolet absorber. A hindered amine light stabilizer does not absorb ultraviolet rays like an ultraviolet absorber, but exhibits a remarkable synergistic effect when used together with an ultraviolet absorber. In addition to hindered amines, there are some that function as light stabilizers, but they are often colored and are not preferred for the (I) layer in the present invention.

  Examples of hindered amine light stabilizers include dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1 , 3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {{2, 2,6,6-tetramethyl-4-piperidyl} imino}], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2, 6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) separate, 2- (3 , 5-Di-tert-4- Mud alkoxybenzylacetic) -2-n-butyl malonic acid bis (1,2,2,6,6-pentamethyl-4-piperidyl) and the like. The amount of the hindered amine light stabilizer added is usually 0.01% by mass or more, preferably 0.05% by mass or more, with respect to 100% by mass of the resin composition constituting the layer (I) in the present invention. And it is preferable to add in 0.5 mass% or less, Preferably it is 0.3 mass% or less.

  The above-mentioned antioxidant, ultraviolet absorber and anti-wrinkle stabilizer generally tend to cause yellowing as the addition amount increases. Therefore, it is preferable that only the minimum necessary amount is added, and no addition is also preferable. It is.

  In general, the temperature of a solar cell module is raised to about 85 to 90 ° C. due to heat generated during power generation or radiant heat of sunlight. In this case, in order to suppress problems such as fluidization of the (I) layer, a crystalline resin in which a crosslinked structure is formed in the (I) layer with the above-described radical generator or silane coupling agent is used. For example, a method using a resin having a high glass transition point may be used. The preferred crystal melting peak temperature when using a crystalline resin, or the preferred glass transition temperature when using an amorphous resin is 100 ° C. or higher, more preferably 110 ° C. or higher, and even more preferably 120 ° C. or higher. It is. Moreover, 160 degrees C or less is preferable, More preferably, it is 150 degrees C or less, More preferably, it is 145 degrees C or less, More preferably, it is 140 degrees C or less. If the upper limit temperature is in the above range, it is preferable because it can be sealed without excessively high temperature in the solar cell element sealing step, and if the lower limit temperature is in the above range, the (I) layer flows during use. It is preferable that problems such as these are difficult to occur.

  The flexibility of the (I) layer in the present invention may be appropriately adjusted in consideration of the shape, thickness, installation location, etc. of the applied solar cell. For example, the vibration frequency in dynamic viscoelasticity measurement is 10 Hz and the strain is 0. When the storage elastic modulus (E ′) at a temperature of 20 ° C. is preferably 1 MPa or more, more preferably 5 MPa or more, and even more preferably 10 MPa or more when measured under the conditions of 0.1% and a heating rate of 3 ° C./min. good. If the storage elastic modulus is within the range, it is preferable that the solar cell element is damaged due to excessive stress and the solar cell element is not easily damaged when an impact is applied to the solar cell module. . Further, it is preferably less than 1000 MPa, more preferably 500 MPa or less, and still more preferably 100 MPa or less. If the storage elastic modulus is in such a range, it is difficult to cause problems such as insufficient handling properties when the layer (I) in the present invention is collected in the form of the sheet or the like, and blocking between the sheet surfaces. It is preferable that sufficient flexibility can be imparted when producing a flexible module.

  The total light transmittance of the (I) layer in the present invention is the kind of solar cell to be applied, for example, an amorphous thin film type silicone type or a part that does not block sunlight reaching the solar electronic element (for example, a solar cell element and a back sheet) However, in consideration of the photoelectric conversion efficiency of the solar cell and the handling properties when superposing various members, it is usually preferably 85% or more. More preferably, it is 90% or more.

[(I) Method for forming layer]
Next, the method for forming the (I) layer in the present invention will be described. The thickness is not particularly limited, but is usually 0.03 mm or more, preferably 0.05 mm or more, more preferably 0.1 mm or more, and about 1 mm or less, preferably 0.7 mm or less, more preferably What is necessary is just 0.5 mm or less.
Since the laminated sheet for solar cells of the present invention has a laminated structure of a flexible (I) layer and a rigid (II) layer, it is applied without reducing handling properties even if the thickness is thin. Depending on the type and configuration of the solar cell, and in view of economy, the (I) layer may be thinned.
(I) As a method for forming a layer, a known method, for example, a single-screw extruder, a multi-screw extruder, a Banbury mixer, a kneader or other melt mixing equipment is used, and an extrusion casting method or a calendar method using a T die. In the present invention, an extrusion casting method using a T die is preferably used from the viewpoints of handling properties and productivity. The molding temperature in the extrusion casting method using a T die is appropriately adjusted depending on the flow characteristics and film forming properties of the resin composition to be used, but is generally 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, More preferably, the temperature is 140 ° C. or higher, and is generally 300 ° C. or lower, preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 180 ° C. or lower. A radical generator or a silane coupling agent is added. In such a case, it is preferable to lower the molding temperature in order to suppress an increase in resin pressure and a fish eye accompanying the crosslinking reaction. Various additives such as radical generators, silane coupling agents, antioxidants, UV absorbers, weathering stabilizers, etc., may be dry-blended with the resin in advance and then supplied to the hopper, or all materials may be melted in advance. It may be supplied after mixing to produce pellets, or a master batch in which only the additive is previously concentrated in the resin may be prepared and supplied. Moreover, on the surface and / or the back surface of the (I) layer in the present invention obtained in the form of a sheet, if necessary, in the step of blocking the sheets when the sheet is used as a scroll or the sealing step of the solar cell element Embossing and various unevenness (cone, pyramid shape, hemispherical shape, etc.) processing may be performed for the purpose of improving the handleability and ease of bleeding. Furthermore, when a sheet is formed, another base film (such as an expanded polyester film (OPET) or an expanded polypropylene film (OPP)) and an extrusion laminate are used for the purpose of improving the handleability when forming the sheet. Lamination may be performed by a method such as a sand lamination method.
Further, as will be described later, extrusion lamination onto the polyphenylene ether resin layer in the (II) layer, co-extrusion with the polyphenylene ether resin layer in the (II) layer, etc. are also preferable because the manufacturing process can be shortened.

<(II) layer>
The layer (II) in the laminated sheet for solar cells of the present invention is a base material layer having a polyphenylene ether-based resin layer made of a resin composition containing polyphenylene ether as a main component on the surface in contact with the (I) layer. The (II) layer may be composed only of the polyphenylene ether resin layer, and one or more other layers are provided on the surface opposite to the surface in contact with the (I) layer in the polyphenylene ether resin layer. It may be provided. Examples of other layers include an intermediate layer for exhibiting mechanical strength, insulation and heat resistance, and a gas barrier layer.

[Polyphenylene ether resin layer]
The lower limit of the content of polyphenylene ether as the main component of the polyphenylene ether-based resin layer is not particularly determined, but is preferably 50% by mass or more, more preferably 65% by mass or more, and 80% by mass. % Or more is more preferable. If it is this range, durability, a flame retardance, dimensional stability and high mechanical strength, high adhesiveness with a sealing resin layer, etc. can be achieved.

  Specific examples of polyphenylene ether include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2-methyl-6- 6). Ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2,6-dipropyl-1,4-phenylene) ether, poly (2-ethyl-) 6-propyl-1,4-phenylene) ether, poly (2,6-dimethoxy-1,4-phenylene) ether, poly (2,6-dichloromethyl-1,4-phenylene) ether, poly (2,6 -Dibromomethyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,6-ditolyl-1,4-phenylene) Ether, poly (2,6-dichloro-1,4-phenylene) ether, poly (2,6-dibenzyl-1,4-phenylene) ether, poly (2,5-dimethyl-1,4-phenylene) ether, etc. Is mentioned. Among them, poly (2,6-dimethyl-1,4-phenylene) ether is preferably used because it is easily available industrially.

  Further, it may be a copolymer obtained by grafting a styrene compound to polyphenylene ether. Examples of the polyphenylene ether grafted with a styrene compound include a copolymer obtained by graft polymerization of styrene, α-methylstyrene, vinyltoluene, chlorostyrene and the like as the styrene compound to the polyphenylene ether.

  Furthermore, the polyphenylene ether may be modified with a modifying agent having a polar group. For example, acid halide, carbonyl group, acid anhydride, acid amide, carboxylic acid ester, acid azide, sulfone group, nitrile group, cyano group, isocyanate ester, amino group, imide group, hydroxyl group, epoxy group, oxazoline group, thiol Group and the like.

  The range of molecular weight preferable as polyphenylene ether used in the present invention is usually preferably 30000 or more, more preferably 40000 or more, and further preferably 40000 or more as a lower limit with respect to the weight average molecular weight measured in terms of polystyrene by gel permeation chromatography (GPC). The upper limit is preferably 100,000 or less, more preferably 90000 or less, and even more preferably 80000 or less. If the molecular weight is within this range, the balance between extrusion moldability, mechanical properties, flame retardancy, and the like is achieved. I can take it.

For the purpose of improving physical properties such as extrusion moldability, impact resistance, heat resistance, flame retardancy and adhesion to the above polyphenylene ether, GPPS (general purpose polystyrene), HIPS (impact polystyrene), ABS (acrylonitrile- Styrene such as butadiene-styrene, SEBS (hydrogenated styrene-butadiene-styrene block copolymer), SBS (styrene-butadiene-styrene block copolymer), and SEPS (hydrogenated styrene-isoprene-styrene block copolymer). Resin, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-propylene-nonconjugated diene copolymer, ethylene-ethyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene -Vinyl acetate-Glycidyl methacrylate copolymer Body and ethylene - propylene -g- ethylene resin such as maleic anhydride copolymer, polyester polyether elastomers, polyester-based resins such as a polyester polyester elastomer, polyamide resin, polyphenylene sulfide resin be adequate amount preferred.
Among them, since the compatibility with the polyphenylene ether resin is excellent and the adhesiveness with the (I) layer is also good, a styrene resin is preferably used, and further, an unsaturated hydrocarbon site such as butadiene is used. Hydrogenated elastomers such as SEBS (hydrogenated styrene-butadiene-styrene block copolymer) that are not contained are suitable for use because they are less prone to gelation and blistering during extrusion molding.
These addition amounts are preferably blended in appropriate amounts within a range not exceeding the mass% of the polyphenylene ether described above. For example, polystyrene resin and polyethylene resin are 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more. By blending in this range, the melt processability and impact resistance are improved. In addition, if it is added in an amount of 40% by mass or less, preferably 30% by mass or less, more preferably 25% by mass or less, and still more preferably 20% by mass or less, the heat resistance is excessively reduced or the flame retardancy is inhibited. It is preferable because there are no problems.

Since polyphenylene ether has an aromatic ring and oxygen atom in the unit skeleton, it easily forms a carbonized layer during combustion, and also has radical scavenging ability due to the presence of active hydrogen, and suppresses molecular chain breakage. Because of its easy characteristics, the resin is excellent in flame retardancy without causing dripping of the molten resin.
In addition, the addition of halogen flame retardants such as brominated biphenyl ether, metal hydroxide flame retardants such as magnesium hydroxide, inorganic flame retardants such as nitrogen compounds and antimony compounds can improve the flame retardancy. Although possible, phosphorus-based flame retardants described below are preferable from the viewpoints of environmental load, imparting flame retardancy, and ensuring mechanical strength.

Phosphorus flame retardants include triphenyl phosphate, trixylenyl phosphate, triethyl phosphate, cresyl phenyl phosphate, xylenyl phosphate, resorcinol bis (diphenyl) phosphate, 2-ethylhexyl diphenyl phosphate, dimethyl methyl phosphate, triallyl phosphate, etc. Phosphoric acid ester flame retardants, condensed phosphoric acid ester flame retardants such as aromatic condensed phosphoric acid esters, phosphazene flame retardants such as phosphonitrile phenyl ester, red phosphorus, etc. are preferably used. In view of the above, a flame retardant having a boiling point and a thermal decomposition temperature of about 400 ° C. or higher is preferable, industrially easily available and inexpensive triphenyl phosphate, industrially easily available and highly decomposed condensed phosphate ester, Such Sufazen flame retardants are preferred.
These are preferably added in an amount of 30% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less. Within this range, the addition of the flame retardant is preferable because the heat resistance is not lowered excessively and the environment is not contaminated as a volatile gas during the melt processing. Moreover, as a lower limit of the number of added parts, it is 0.1 mass% or more, Preferably it is 1.0 mass% or more, More preferably, it is 3.0 mass% or more. If it is this range, since the effect which improves a flame retardance is acquired, it is suitable.

  As will be described later, when a polyphenylene ether-based resin composition containing polyphenylene ether as a main component is extruded, it is extruded at a relatively high temperature (260 ° C. to 320 ° C.). May be required. An example of the heat resistance index is a weight reduction temperature by thermogravimetric analysis. For the phosphorus-based flame retardant described above, the 5% weight loss temperature when heated from normal temperature to 400 ° C. at an increase rate of 10 ° C./min in an inert gas atmosphere is preferably 150 ° C. or more, and more preferably It is 200 degreeC or more, More preferably, it is 250 degreeC or more, Most preferably, it is 275 degreeC or more. Within the above range, the phosphorus-based flame retardant volatilizes during molding and deteriorates the working environment, reduces the flame retardancy of the molded sheet, or promotes reaction with the base material during extrusion molding. Difficult to cause problems such as worsening the appearance. Moreover, there is no restriction | limiting in particular in an upper limit, If it is more than extrusion molding temperature, it is preferable.

  In addition to the above components, other additional components as necessary within the range not impairing the characteristics and effects of the present invention, such as carbon filler, glass filler, talc, mica, etc., in order to improve heat resistance and mechanical strength Inorganic fillers, heat stabilizers, antioxidants, plasticizers (oil, low molecular weight polyethylene, epoxidized soybean oil, polyethylene glycol, fatty acid esters, etc.) for improving extrusion moldability, difficult for improving flame retardancy In order to improve the combustion aid and durability, a weather resistance (light) improver, a nucleating agent and various colorants may be added.

In the polyphenylene ether used in the present invention, the lower limit of the intrinsic viscosity determined from the viscosity measured in chloroform at 30 ° C. is preferably 0.2 dl / g or more, more preferably 0.3 dl / g or more, and 0 More preferably, it is 4 dl / g or more. If the value of the intrinsic viscosity is within this range, problems such as inferior heat resistance, flame retardancy, and mechanical strength are unlikely to occur. The upper limit is preferably 0.8 dl / g or less, more preferably 0.7 dl / g or less, and further preferably 0.6 dl / g or less. When the value of the intrinsic viscosity is within this range, it is difficult to cause problems such as the shear viscosity becomes too high and the productivity is inferior.
Further, for the purpose of improving moldability, polyphenylene ethers having different intrinsic viscosities may be used in combination.

  Commercially available polyphenylene ethers are sold under the trade names “PPO646”, “PPO640”, and “PPO630” by SABIC Innovation Plastics and under the tradenames “S201A” and “S202” from Asahi Kasei Chemicals, respectively. Is possible.

The polyphenylene ether-based resin layer may be transparent or colored. For the purpose of coloring, when used mainly as a back sheet, the solar cell of the present invention is formed by reflecting or absorbing solar rays that have passed through the solar cells to increase power generation efficiency and by reflecting or absorbing ultraviolet rays. The purpose is to prevent ultraviolet deterioration of the laminated sheet constituting material and improve various properties such as weather resistance, durability, heat resistance, thermal dimensional stability and strength of the laminated sheet for solar cell. In particular, whitening is effective in reflecting sunlight and improving power generation efficiency.
Furthermore, the design and decoration of the solar cell module can be improved by various colorings including blackening.
The “light reflection” in the light reflective colored layer includes light scattering as well as light reflection.

  As a coloring method, a method of dispersing and adding a pigment as a colorant, a method of adding an incompatible polymer or fine particles to a substrate, and forming voids or bubbles at the blend interface during film stretching, or the like can be used.

As a pigment used for coloring, a white pigment, a black pigment, etc. are mentioned preferably. Although it does not specifically limit as a white pigment, For example, calcium carbonate, anatase type titanium oxide, rutile type titanium oxide, zinc oxide, lead carbonate, barium sulfate, basic lead carbonate, basic lead sulfate, basic silicic acid Lead, zinc white, zinc sulfide, lithopone and the like can be used. As the titanium oxide, the rutile type is preferable because it causes less yellowing after irradiation with light for a longer time than the anatase type, and is suitable for suppressing changes in color difference.
Among the above white pigments, at least one inorganic fine particle selected from the group consisting of rutile type titanium oxide, barium sulfate, calcium carbonate and silicon dioxide is preferable from the viewpoint of stability and non-heavy metal compound, and barium sulfate and rutile type oxidation are preferable. Titanium is more preferable, and barium sulfate is more preferable.

  Barium sulfate is a good white material that is physically and chemically stable and exhibits a reflectance of 99% or more over almost the entire visible light region, and is a substance used as a white standard. Moreover, it is a material with high coloring property and concealment property, is efficiently whitened, and has a high light reflectivity effect as a solar cell backsheet.

  The black pigment is not particularly limited, and carbon black, black iron oxide, and the like are used. Among them, carbon black is preferably used from the viewpoint of long-term stability. In order to develop other colors (blue, red, yellow, etc.), it may be added to the above-mentioned resin by adding a dye or a pigment, but the addition of a pigment is more preferable from the viewpoint of long-term stability.

The above-mentioned polyphenylene ether-based resin composition is formed by adding the above-mentioned components to polyphenylene ether, but a commercially available product that has been mixed in advance may be purchased and used.
Commercially available polyphenylene ether-based resin compositions are trade names “Noryl PX9406”, “Noryl LTA1350” and “Noryl N300” from SABIC Innovation Plastics and trade names “Zylon 540Z” and “Zylon 640Z” from Asahi Kasei Chemicals. "Zyron 740Z" is sold by Mitsubishi Engineering Plastics as "Iupiace LN91", "Iupiace AN70", "Iupiace AH90", "Iupiace TX903B", and "Remalloy BX528-A3".

The polyphenylene ether-based resin layer in the present invention can be produced by a conventionally known method.
Each compounding agent may be kneaded in advance or may be kneaded all at once during film formation.
The molding method may be any of extrusion, calendering, and casting, but extrusion molding is preferred from the viewpoint of easy collection of thin film products and production efficiency. At this time, since extrusion molding is performed at a relatively high temperature (about 260 ° C. to 320 ° C.), thermal decomposition products such as sag (resin deposits) and foreign matters are generated at the time of molding, and the resulting film or sheet has an appearance. It is easily damaged. As countermeasures, a method of opening the lip gap of the die and reducing the shear rate, a method of plating the surface of the die channel, and other resins that have good slidability between the polyphenylene ether resin layer and the metal (for example, high-density polyethylene resin) There are a method of co-extrusion and a method of co-extrusion of the polyphenylene ether resin layer and the (I) layer to obtain the laminated sheet for solar cell of the present invention. When other resins are coextruded, the other resins are usually peeled off after cooling and solidification. However, when other resins are used by being laminated on the solar cell sheet of the present invention, it is possible to adopt an aspect in which the other resins are not peeled off only on one side.

In order to perform extrusion molding, the shear viscosity measured by the Koka type flow tester is preferably 50 Pa · s (500 poise) or more when the shear rate at 300 ° C. is 100 sec ⁻¹ , and 100 Pa · s (1000 poise) or more. More preferably, 500 Pa · s (5000 poise) or more is more preferable. If the shear viscosity is within this range, problems such as poor physical properties are unlikely to occur, and is preferably 5000 Pa · s (50000 poise) or less, more preferably 3500 Pa · s (35000 poise) or less, more preferably 2000 Pa · s (20000 poise) or less. Further preferred. If the shear viscosity is within this range, the extrudability is insufficient and the molding machine is not overloaded, which is preferable from the viewpoint of productivity.
In order to adjust the shear viscosity to the above value, adjust the molecular weight of polyphenylene ether, adjust the component ratio of styrene resin, ethylene resin, polyamide resin, etc., adjust the type and amount of flame retardant. Other methods include adding a plasticizer.

  The deflection temperature under load of the polyphenylene ether-based resin layer in the present invention is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and more preferably 140 ° C. or higher. If the deflection temperature under load is 100 ° C. or higher, the heat resistance in the sealing process, which will be described later, is difficult to cause problems such as a large dimensional change, and the upper limit value is not particularly defined, but is 200 ° C. or lower. Preferably, it is 180 ° C. or lower, and more preferably 160 ° C. or lower. If the deflection temperature under load is 200 ° C. or less, the above-mentioned shear viscosity becomes too high and it is difficult to cause problems such as poor productivity.

  In general, in a two-component blend system of polyphenylene ether and polystyrene, the deflection temperature under load changes linearly depending on the blending ratio, the deflection temperature under load is between about 190 ° C. and about 80 ° C. when the polyphenylene ether is between 100% and 0%. Change to ° C. Therefore, in order to improve the deflection temperature under load, it is effective to increase the content of polyphenylene ether. In addition, the addition amount of a flame retardant or plasticizer that lowers the deflection temperature under load is reduced, or polyphenylene sulfide or polyamide is reduced. It is also effective to blend a high heat-resistant resin such as or blend an inorganic filler.

  In addition, since polyphenylene ether is supplied in large quantities as a general-purpose engineering plastic, it is also preferable in terms of having supply stability even if the amount of consumption further increases in the future as a solar cell application for which future demand is expected to increase.

[Middle layer]
In the layer (II) in the present invention, by forming an intermediate layer, the thickness of the entire laminated sheet for solar cells can be increased, and mechanical strength, insulation, and heat resistance can be further improved. preferable. Examples of the resin forming the intermediate layer include polyethylene resins, polypropylene resins, cyclic polyolefin polymers, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins). ), Polyvinyl chloride resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, fluorine resin, polyamide resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, silicone resin , Polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin and the like.
Among the above, olefin resins such as polyethylene resins, polypropylene resins, and cyclic polyolefin polymers are excellent in hydrolysis resistance and excellent in durability, and because the specific gravity is light, it leads to weight reduction of the entire sheet. Among polyester resins and polyphenylene sulfide resins, those obtained by biaxial stretching are particularly preferable because they have very high mechanical strength (elastic modulus). A fluororesin has both flame retardancy and durability, and is preferable for the purpose of improving physical properties.

[Gas barrier layer]
As the gas barrier layer, a layer having an inorganic thin film layer can be preferably used. In addition, a metal thin film such as aluminum foil or a thermoplastic polymer can be used as the gas barrier layer, and any material that can be used for a normal packaging material can be used without any particular limitation.
Specifically, polyolefins such as homopolymers or copolymers such as ethylene, propylene and butene, amorphous polyolefins such as cyclic polyolefin, polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, nylon 6, nylon 66, polyamide such as nylon 12, copolymer nylon, ethylene-vinyl acetate copolymer partial hydrolyzate (partially saponified product, EVOH), polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polycarbonate , Polyvinyl butyral, polyarylate, acrylate resin and the like. Among these, polyester, polyamide, and polyolefin are preferable from the viewpoint of film properties. Of these, polyethylene terephthalate and polyethylene naphthalate are more preferable from the viewpoint of film strength. Furthermore, polyethylene naphthalate is preferable in terms of weather resistance and hydrolysis resistance.

  Examples of the inorganic substance constituting the inorganic thin film layer include silicon, aluminum, magnesium, zinc, tin, nickel, titanium, hydrogenated carbon, and the like, or oxides, carbides, nitrides, or mixtures thereof. Diamond-like carbon mainly composed of silicon oxide, aluminum oxide, and hydrogenated carbon is preferable. In particular, silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide are preferable in that high gas barrier properties can be stably maintained.

  The material gas that can be used for chemical vapor deposition is preferably composed of at least one gas. For example, in the formation of a silicon compound thin film, it is preferable to use a rare gas such as ammonia, nitrogen, oxygen, hydrogen or argon as the second source gas for the first source gas containing silicon.

Examples of the first source gas containing silicon include monosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane. Ethoxysilane, diphenyldiethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, hexamethyldisiloxane, hexamethyldisilazane, etc. alone or 2 Can be used in combination.
The source gas may be liquid or gas at room temperature, and the liquid source can be vaporized by a source vaporizer and supplied into the apparatus. In the catalytic chemical vapor deposition method, monosilane gas is preferable from the viewpoint of deterioration of the heated catalyst body, reactivity, and reaction rate.

  As a method for forming the inorganic thin film layer of the gas barrier film, any of a vapor deposition method and a coating method can be used, but the vapor deposition method is preferable in that a uniform thin film having a high gas barrier property can be obtained. This vapor deposition method includes methods such as physical vapor deposition (PVD) or chemical vapor deposition (CVD). Examples of physical vapor deposition include vacuum deposition, ion plating, and sputtering, and chemical vapor deposition includes plasma CVD using plasma and a catalyst that thermally decomposes a material gas using a heated catalyst body. Examples include chemical vapor deposition (Cat-CVD).

The (II) layer in the present invention is formed with a polyphenylene ether-based resin layer on the surface in contact with the (I) layer. Furthermore, by forming a polyphenylene ether-based resin layer on the surface opposite to the surface in contact with the (I) layer, it is easy to develop long-term adhesiveness, durability, and flame resistance with a sealing material or a junction box. it can. Moreover, you may use as a multilayer structure which formed the above-mentioned intermediate | middle layer and gas-barrier layer.
The thickness of the polyphenylene ether-based resin layer when used as a multilayer structure is not particularly limited, but exhibits excellent properties of the polyphenylene ether-based resin layer such as flame retardancy, heat resistance, and mechanical strength. Therefore, it is preferable to exceed 50% of the total thickness, more preferably 65% or more, and still more preferably 80% or more. In the present invention, the thickness ratio of the polyphenylene ether-based resin layer exceeds 50% of the total thickness means that the total thickness of each polyphenylene ether-based resin layer including at least the surface in contact with the (I) layer is (II) the entire layer This means that the thickness exceeds 50%.

In the case of the structure in which each layer described above is formed into a multi-layer, or in the case of a polyphenylene ether-based resin single layer, the total thickness is preferably 0.025 mm or more, more preferably 0.05 mm or more, and 0.075 mm or more. More preferably, it is 0.1 mm or more. If the thickness is within this range, problems such as insufficient mechanical strength are unlikely to occur, and the upper limit is not particularly determined. However, if it is too thick, handling properties will be reduced, so practically 0.5 mm or less. Is preferably 0.4 mm or less, and more preferably 0.3 mm or less.
In addition, in the case of the structure which consists only of a polyphenylene ether-type resin layer, when there are two or more polyphenylene ether-type resin layers from which a composition differs, of course, it is contained in a structure.

  When each of the above-described layers is formed into a multi-layer, a method by co-extrusion or a known adhesive or pressure-sensitive adhesive may be used. The polyphenylene ether-based resin layer in the present invention has an affinity for an adhesive or a pressure-sensitive adhesive, and has a strong adhesive force, so that it can be easily formed into multiple layers. Moreover, you may use well-known methods, such as a corona discharge process, a plasma process, and a flame process, in order to improve the affinity with respect to an adhesive agent.

In addition, it is known to develop surface characteristics such as scratch resistance and antifouling on the surface that is the outermost surface when formed as a solar cell module, that is, the surface opposite to the surface in contact with the (I) layer. The hard coat treatment or antifouling treatment may be applied.
Moreover, you may perform the process which forms an unevenness | corrugation on the surface for the purpose of improving the slipperiness of a surface and improving the handleability at the time of module assembly or construction. In order to form irregularities on the surface, a method of embossing at the time of film forming, a method of putting inorganic particles such as silica and talc into the surface layer, a method of co-extrusion of a layer containing inorganic particles and peeling after cooling and solidification Any means may be used. Of course, the surface may be smoothed by using a known method such as coating from the viewpoint of design properties.

In the present invention, the (II) layer is preferably excellent in flame retardancy. By having flame retardancy, for example, it is possible to prevent the spread of fire when a fire occurs, which is preferable for safety. However, since flame resistance is not necessarily required for all solar cell modules depending on applications and usage conditions, the present invention does not positively exclude those having inferior flame resistance.
The evaluation of flame retardancy is judged by the combustion behavior in the combustion test. As described above, polyphenylene ether is a resin having excellent flame retardancy. To impart flame retardancy, the content of polyphenylene ether in the polyphenylene ether-based resin layer is increased, the amount of flame retardant added is increased, and components such as lubricants are added. There are methods such as decreasing the thickness ratio and increasing the thickness ratio of the entire polyphenylene ether-based resin layer.

  Generally, since the laminated sheet for solar cells is exposed to the external environment, hydrolysis resistance, which is one of durability, is necessary to stably protect the solar cells for a long period of time. This is evaluated by measuring physical properties after accelerated evaluation under any environment. In order to impart hydrolysis resistance, low molecular weight components (such as additives) may be reduced, or hydrolyzable compositions (polyamide, polyester, polycarbonate, etc.) may be reduced. It is also possible to mix a hydrolysis inhibitor (carbodiimide or the like).

  Mechanical strength substituted by tensile modulus, tensile elongation at break, etc. is necessary for handling in the module formation process and protection of the cell from external impact after module installation. (II) The thickness of the layer may be increased, or a component having impact resistance such as an elastomer may be added.

  The storage elastic modulus of the (II) layer in the present invention may be appropriately adjusted in consideration of the shape, thickness, installation location, etc. of the applied solar cell. For example, the vibration frequency in dynamic viscoelasticity measurement is 10 Hz, the strain The storage elastic modulus (E ′) at a temperature of 20 ° C. when measured under the conditions of 0.1% and a temperature increase rate of 3 ° C./min is preferably 1000 MPa or more, more preferably 1500 MPa or more, and further preferably 2000 MPa or more. I just need it. If the storage elastic modulus is within such a range, problems such as stretching during film transport and wrinkles are unlikely to occur, and the modularization process to be described later after (I) layer integration with the layer, etc. It is preferable that handling property can be imparted. The upper limit is not particularly limited, but is preferably 5000 MPa or less, more preferably 4000 MPa or less, and still more preferably 3000 MPa or less. If the storage elastic modulus is within such a range, it is preferable that problems such as difficulty in handling due to being too hard when the film is conveyed are suitable. In order to adjust the storage elastic modulus within this range, the storage elastic modulus of the polyphenylene ether resin layer in the (II) layer is adjusted, or the polyphenylene ether resin layer is combined with another layer having a high storage elastic modulus. You can do it.

  Moreover, the crosslinking EVA which is a general sealing resin has a crosslinking step of about 150 ° C. and takes about 30 minutes. Therefore, in order to avoid trouble in the solar cell module forming step (sealing step), the (II) layer in the present invention needs to have heat resistance and a small dimensional change.

  The heat resistance is evaluated by a dimensional change rate, and the dimensional change rate of the (II) layer when heated at 150 ° C. for 30 minutes in a dry air stream is 3% or less, preferably 1% or less, more preferably May be 0.5% or less. If the dimensional change rate is within such a range, it is preferable that problems such as inferior productivity are unlikely to occur. In order to adjust the dimensional change rate within this range, the deflection temperature under load of the polyphenylene ether-based resin layer in the (II) layer is adjusted to the predetermined value described above, or the dimensional change of the polyphenylene ether-based resin layer is small. It can be combined with other layers.

<Laminated sheet for solar cell>
The laminated sheet for solar cell of the present invention is formed by laminating and integrating the (I) layer and the (II) layer. The preferred ranges of the thicknesses of the (I) layer and the (II) layer are as described above, and the thickness ratio is not particularly limited. However, the overall thickness of the solar cell laminate sheet of the present invention is preferably 0.1 mm or more, more preferably 0.15 mm or more, and even more preferably 0.2 mm or more, when handling a solar cell module. In addition, it is preferable that 1.0 mm or less, more preferably 0.8 mm or less, and still more preferably 0.5 mm or less, which does not cause problems such as inhibiting productivity.

In order to produce the laminated sheet for solar cells of the present invention, the method for laminating the (I) layer and the (II) layer is not particularly limited, and a conventionally known method can be used. Specifically, in the state where the (I) layer and the (II) layer are superposed, heating and pressure bonding are used to laminate, and when the (I) layer or (II) layer is extruded, the (II) layer or ( Examples thereof include an extrusion laminating method in which the I) layer is unwound and pressed and laminated by a cast unit portion, a coextrusion method in which the (I) layer and the (II) layer are simultaneously extruded, a dry laminating method, a calendering method, and the like.
These may be used in combination. Among these, after forming the (II) layer in advance, the method of laminating the (I) layer by the extrusion laminating method is excellent in productivity, and the sealing resin layer itself as the (I) layer It is preferable because handling is improved.

In addition, as will be described later, in the solar cell module manufacturing process, a solar cell element may be sealed and a thermocompression bonding process may be performed at about 150 ° C. for about 30 minutes in order to promote a crosslinking reaction of the sealing material. . Therefore, when the (I) layer and the (II) layer are laminated, it is only necessary to exhibit an adhesive property that can be handled. In the present invention, although it depends on the combination with the sealing resin layer to be applied, it is also possible to improve the adhesiveness after the thermocompression bonding step. In the laminated sheet for solar cells of the present invention, (I) after the heat treatment at 150 ° C. for 30 minutes under a pressure of 0.1 MPa (1 kgf / cm ² ) or more and 1.0 MPa (10 kgf / cm ² ) or less. The peel strength between the layer and the layer (II) is preferably 10 N / 15 mm or more, more preferably 20 N / 15 mm or more, and even more preferably 30 N / 15 mm or more. If the peel strength is within the range, the sealing resin layer and the outer layer sheet are used in the manufacturing process of the solar cell module, when fixed to a structure such as a roof, or when used as a flexible module. This is suitable because it is difficult to cause problems such as peeling of water and inflow of moisture or mixing of foreign substances. Moreover, although an upper limit is not restrict | limited in particular, if it is about 150 N / 15mm practically, it has sufficient adhesiveness.

<Solar cell module>
The laminated sheet for solar cells of the present invention (hereinafter also referred to as this laminated sheet) is used, and the solar cell element is fixed to the transparent substrate (front sheet) and the sealing resin layer as the upper protective material, and the lower part is fixed with the laminated sheet. Thus, the solar cell module of the present invention can be produced. Examples of such solar cell modules include various types.
As a specific example, as shown in FIG. 1, the transparent substrate 10, the sealing resin layer 12, the solar cell elements 14A and 14B, and the solar cell laminated sheet of the present invention (in this case, in this order from the sunlight receiving side) (I) Layer 16A is disposed on the solar cell element side) 16A and 16B are laminated, and (II) junction box 18 (electricity generated from the solar cell element is externally provided on the lower surface of layer 16B. The terminal box for connecting the wiring to be taken out is bonded. The solar cell elements 14A and 14B are connected by a wiring 20 in order to conduct the generated current to the outside. The wiring 20 is taken out to the outside through through holes (not shown) provided in the laminated sheets 16A and 16B for solar cells, and is connected to the junction box 18.
Since the solar cell module deteriorates when moisture enters the inside, when attaching accessories such as a junction box, ensure sufficient sealing so that outside air does not enter the inside of the solar cell module. Although it is necessary, according to the laminated sheet for solar cells of the present invention, since it can be bonded only by heat treatment, it becomes possible to easily and reliably prevent the intrusion of outside air.

  In addition, in the solar cell module of the present invention, when the sealing resin layer is used in two or more parts, it is composed of the same composition as the resin composition constituting the (I) layer in the present invention in all parts. A sealing resin layer may be used, or a sealing resin layer made of a different resin composition may be used. When the sealing resin layer is used for a portion requiring light transmittance, it must be transparent, but when used as a lower protective material, the sealing resin layer (I) is not transparent. It doesn't matter.

  As the transparent substrate, glass, or a single-layer or multilayer plastic sheet such as acrylic resin, polycarbonate, polyester, or fluorine-containing resin is used. In the case of plastic, for the purpose of imparting gas barrier properties, an inorganic thin film is formed in the same manner as the gas barrier layer constituting the laminated sheet for solar cells, or heat resistance, weather resistance, mechanical strength, chargeability, For the purpose of improving dimensional stability, etc., crosslinking agents, antioxidants, light stabilizers, UV absorbers, antistatic agents, reinforcing fibers, flame retardants, preservatives, etc. are added, and various sheets are added to this. Can be stacked. The thickness of the transparent substrate can be appropriately set in view of strength, gas barrier properties, durability, and the like.

  The solar cell element is arranged and wired between the sealing resin layers. Examples thereof include a single crystal silicone type, a polycrystalline silicone type, an amorphous silicone type, various compound semiconductor types, a dye sensitized type, and an organic thin film type.

  Although it does not specifically limit as a manufacturing method of the solar cell module at the time of using the laminated sheet for solar cells of this invention, Generally, it laminates | stacks in order of a transparent substrate, a sealing resin layer, a solar cell element, and this laminated sheet. , A step of aligning, a step of vacuum-sucking them and thermocompression bonding them, and a step of trimming the protruding sealing resin to a predetermined dimension. In this laminated sheet, a layer having a sealing resin layer and a polyphenylene ether-based resin layer is laminated in advance, and by using this, the lamination, alignment step, trimming step, etc. in the above steps can be easily performed. I can do it.

  The solar cell module of the present invention can be suitably used for various applications regardless of small size, large size, indoors, and outdoors due to the excellent durability, flame retardancy, dimensional stability and high mechanical strength of the laminated sheet.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

  The constituent material used when producing the laminated sheet for solar cells below is illustrated.

As the (I) layer, the following sheet was used.
EVA1 : VISTASOLAR (crosslinker-containing EVA resin) (thickness 0.5 mm) manufactured by ETIMEX
EVA2 : Extruded with a φ25 mm twin screw extruder using EVAFLEX150 manufactured by Mitsui DuPont, and cooled and solidified with a 20 ° C. cast roll to obtain a sheet having a thickness of 0.5 mm.
PO1 : A sheet having a thickness of 0.5 mm was obtained in the same manner by using a raw material obtained by adding 1.0 part by mass of Arupema Yoshitsune Lupelox TBEC as a crosslinking agent to 100 parts by mass of Mitsui Chemicals Tuffmer A4085.
PO2 : A sheet having a thickness of 0.5 mm was obtained in the same manner by using a raw material obtained by adding 0.5 parts by mass of Momentive SILQUEST as a silane coupling agent to 100 parts by mass of Mitsui Chemicals Tuffmer A4085.
PO3 : Bond Fast 7M manufactured by Sumitomo Chemical Co., Ltd. was used to extrude with a φ25 mm twin screw extruder, and cooled and solidified with a 40 ° C. cast roll to obtain a sheet with a thickness of 0.5 mm.

The sheet shown below was used as the (II) layer.
PPE1 : Polyphenylene ether resin composition (deflection temperature under load; 150 ° C., containing 89% by mass of polyphenylene ether, containing 7% by mass of triphenyl phosphate, manufactured by SABIC Innovation Plastics, trade name “Noryl N300”) Machine, barrel set temperature set to 240-300 ° C., extruded with 1150 mm width single layer die (set temperature 300 ° C.), and cooled and solidified with cast roll set to 80 ° C. to produce 0.05 mm thick sheet .

PPE2 : A sheet was produced in the same manner as PPE1 except that the thickness of 0.05 mm was adjusted to 0.22 mm by adjusting the speed of the cast roll.
PPE3 : A sheet having a thickness of 0.05 mm was prepared in the same manner as PPE2, except that a polyphenylene ether-based resin composition (deflection temperature under load; 90 ° C.) was used and the set temperature of the cast roll was set to 60 ° C.
PET1 : Polyethylene terephthalate (PET) resin film (Lumirror X10S manufactured by Toray Industries, Inc., thickness 0.05 mm).
PEN1 : Polyethylene naphthalate (PEN) resin film (Teonex Q51C, manufactured by Teijin DuPont Co., Ltd., thickness 0.025 mm).
ETFE1 : Polyethylenetetrafluoroethylene (ETFE) resin film ( Aflex manufactured by Asahi Glass Co., Ltd., thickness 0.025 mm).
PET2 : White PET resin film (Lumirror E20 manufactured by Toray Industries, Inc., thickness 0.188 mm).
COC1 : Extruded with a cyclic olefin copolymer (COC) resin (TOPAS 6015, thickness 0.05 mm, manufactured by Topas Advanced Polymers Co., Ltd.) with a φ25 mm twin screw extruder, and cooled and solidified with a cast roll at 80 ° C. Thus, a sheet having a thickness of 0.05 mm was obtained.
PC1 : A sheet having a thickness of 0.05 mm was obtained in the same manner as COC 1 except that polycarbonate (PC) resin (Caliver 301 manufactured by Sumitomo Dow Co., Ltd.) was used.
PMMA1 : A sheet having a thickness of 0.05 mm was obtained in the same manner as COC1 except that a polymethyl methacrylate (PMMA) resin film (Sumitex MH manufactured by Sumitomo Chemical Co., Ltd.) was used.

  The following evaluation was performed using the said film which comprises the laminated sheet for solar cells. The results are shown in Table 1.

(1) Durability Tensile of sample taken after processing sample for 144 hours under conditions of temperature 120 ° C, humidity 100%, 2 atm in a highly accelerated life tester (pressure cooker tester; EHS-211M manufactured by ESPEC) The breaking stress value was measured according to JISK7127 under conditions of a temperature of 20 ° C. and a test speed of 200 mm / min. The ratio (retention rate) of the measured value after the acceleration test to the initial measured value was measured as a% value, and the durability was evaluated according to the following criteria.
○: Retention ratio is 80% or more Δ: Retention ratio is 50% or more and less than 80% ×: Retention ratio is less than 50% or the sample shape cannot be maintained

(2) Flame retardance A test piece was cut out to a length of 200 mm and a width of 50 mm, wound in a cylindrical shape in the width direction, and the side surface was fixed with an adhesive tape. The cylinder was fixed vertically with a clamp, the sample was fixed vertically with the clamp, a 20 mm flame was used with a gas burner, and a 3 second indirect flame was performed twice at the lower end. The flame retardancy was evaluated according to the following criteria.
○: Combustion duration is within 30 seconds, and no molten resin is dripped.
X: Combustion duration exceeds 30 seconds, or molten resin is dripped.

(3) Junction Box Adhesiveness In the sample, a silicone sealant (“TSE392” manufactured by Momentive Co., Ltd.) was applied to the surface opposite to the (I) layer (film thickness after drying: 0.5 mm), and the adhesive strength was as follows: Evaluated by criteria.
○: Adhering well ×: Floating or peeling or Adhering but easily peeling

  As is clear from Reference Example 1, it can be seen that the use of PPE is excellent in durability, flame retardancy, and junction box adhesion. It turns out that it is inferior to durability and a flame retardance when the polyester-type resin of PET and PEN is used from Reference Examples 2 and 3. It can be seen from Reference Examples 4 and 7 that COC and PMMA are inferior in flame retardancy. It can be seen from Reference Example 5 that ETFE is inferior in junction box adhesion. It can be seen from Reference Example 6 that the use of PC is inferior in durability.

Next, the configuration shown in Table 2 (I) layer and the (II) layer was laminated, using a heating press machine 0.1MPa (1kgf / cm ²⁾ or more, 1.0MPa (10kgf / cm ²⁾ or less The laminated sheet of the present invention is prepared by adjusting the pressure to 150 ° C. for 30 minutes, and the heat resistance of the (I) layer, the storage elastic modulus, and between the (I) and (II) layers. The following evaluation was performed on the peel strength. The results are shown in Table 2.

(4) Dimensional stability (heat resistance)
After cutting the sample into 100 mm × 100 mm square and processing the sample for 30 minutes in a circulation oven set at 150 ° C., (II) the absolute value% of the ratio of the dimensional displacement of the layer to the original size was measured. The larger one of the longitudinal direction and the orthogonal direction was noted, and the dimensional stability was evaluated according to the following criteria.
◎: 0.5% or less ○: Over 0.5% to 1.0% or less △: Over 1.0% to 3.0% or less ×: Over 3.0%

(5) Storage elastic modulus Using a viscoelasticity measuring device manufactured by IT Measurement Co., Ltd., trade name “Viscoelastic Spectrometer DVA-200”, a sample (4 mm long, 60 mm wide) was subjected to a vibration frequency of 10 Hz and a strain of 0.1. %, Temperature rising rate 3 ° C./min, 25 mm between chucks, the sample melted from −150 ° C. in the transverse direction (direction perpendicular to the flow direction from the sheet extruder or the longitudinal direction of the roll). The dynamic viscoelasticity was measured until measurement became impossible, and the storage elastic modulus (E ′) (MPa) at 20 ° C. was determined from the obtained data and evaluated according to the following criteria.
◎: 2000 MPa or more ○: 1500 MPa or more and less than 2000 MPa Δ: 1000 MPa or more and less than 1500 MPa ×: less than 1000 MPa

(6) Peel strength A sample was cut into a 150 mm × 150 mm square and treated for 48 hours in a pressure cooker tester under conditions of a temperature of 120 ° C., a humidity of 100%, and 2 atmospheres.
The unprocessed sample and the processed sample were cut out to a width of 15 mm, and the 180 ° peel strength was measured at a test speed of 50 mm / min.
A: Peel strength is 30 N / 15 mm or more B: Peel strength is 20 N / 15 mm or more and less than 30 N / 15 mm B: Peel strength is 10 N / 15 mm or more and less than 20 N / 15 mm X: Peel strength is less than 10 N / 15 mm

In Reference Example A , the substrate (solar cell sheet) was so strongly bonded that it could break, and an accurate value could not be obtained. From Reference Examples A to B and Example 3 , the sealing material containing the crosslinking agent (radical generator) exhibited strong adhesiveness. From Example 4, the sealing material containing the silane coupling agent exhibited strong adhesiveness. From Reference Examples C to D , even a system that did not contain a radical generator or a silane coupling agent showed adhesion more than that of ETFE and PET base materials (Comparative Examples 1 to 3). Further, from Comparative Example 4, when the load deflection temperature of PPE was low, although strong adhesiveness was expressed, heat resistance was insufficient.
Further, from Examples 3 to 4 and Reference Examples A to D , the heat resistance and the storage elastic modulus sufficiently satisfy the desired values, and the heat resistance and handling properties as a solar cell laminated sheet were excellent. .

DESCRIPTION OF SYMBOLS 10 ... Transparent substrate 12 ... Sealing resin layer 14A, 14B ... Solar cell element 16A ... Solar cell laminated sheet (I) layer 16B ... Solar cell laminated sheet (II) layer 18 ... Junction box 20 ... Wiring

Claims (8)

The following (I) layer and the following (II) layer are laminated and integrated, and the dimensional change rate of the following (II) layer when heated at 150 ° C. for 30 minutes in a dry air current is 3% or less. Battery laminated sheet.
(I) Sealing resin layer comprising a resin composition comprising an ethylene-α-olefin copolymer as a main component (II) From a resin composition containing 80% by mass or more of polyphenylene ether on the surface in contact with the (I) layer Base layer having polyphenylene ether resin layer   The laminated sheet for a solar cell according to claim 1, wherein the layer (I) comprises a radical generator or a silane coupling agent. The laminate sheet for solar cells according to claim 1 or 2 , wherein a peel strength between the (I) layer and the (II) layer is 10 N / 15 mm or more. The storage elastic modulus (E ′) at a temperature of 20 ° C. measured at a vibration frequency of 10 Hz, a strain of 0.1%, and a heating rate of 3 ° C./min in the dynamic viscoelasticity measurement of the layer (II) is 1000 MPa. It is the above, The laminated sheet for solar cells of any one of Claim 1 to 3 characterized by the above-mentioned. The (II) layer is a base material layer having a polyphenylene ether-based resin layer made of a resin composition containing 80% by mass or more of polyphenylene ether on the surface opposite to the surface in contact with the (I) layer. The laminated sheet for solar cells according to any one of claims 1 to 4 . The thickness of the polyphenylene ether-based resin layer in the (II) layer is a ratio exceeding 50% of the total thickness of the (II) layer, according to any one of claims 1 to 5. Laminated sheet for solar cells. A solar cell module comprising the laminated sheet for solar cells according to any one of claims 1 to 6 . 8. The solar cell module according to claim 7 , wherein a junction box is bonded to a surface of the laminated sheet for solar cells opposite to a surface in contact with the (I) layer in the (II) layer. 9.