WO2014007212A1

WO2014007212A1 - Protective film for solar cell modules, and solar cell module using same

Info

Publication number: WO2014007212A1
Application number: PCT/JP2013/068037
Authority: WO
Inventors: 康司川島
Original assignee: 恵和株式会社
Priority date: 2012-07-03
Filing date: 2013-07-01
Publication date: 2014-01-09
Also published as: JP2014013791A

Abstract

The purpose of the present invention is to provide: a protective film for solar cell modules, which is capable of preventing defects during thermal fusion bonding; and a solar cell module which uses the protective film for solar cell modules. A protective film for solar cell modules of the present invention is provided with a thermally fusion bonding resin layer; and a synthetic resin that is a main component of the thermally fusion bonding resin layer is crosslinked by irradiation of an electron beam. The thermally fusion bonding resin layer preferably contains a crosslinking agent. The synthetic resin is preferably a polypropylene. The thermally fusion bonding resin layer preferably contains a pigment in a dispersed state. The irradiation dose of the electron beam is preferably from 5 kGy to 300 kGy (inclusive). This protective film for solar cell modules is preferably formed only of the thermally fusion bonding resin layer. The thermally fusion bonding resin layer preferably has an average thickness of from 40 μm to 500 μm (inclusive).

Description

Protective film for solar cell module and solar cell module using the same

The present invention relates to a protective film suitably used for a solar cell module and a solar cell module using the protective film.

In recent years, solar power generation as a clean energy source has attracted attention due to increasing awareness of environmental problems such as global warming, and solar cells having various forms have been developed. This solar battery is generally composed of a plurality of solar battery modules that are packaged by a plurality of solar battery cells wired in series or in parallel.

The solar cell module is required to have sufficient durability and weather resistance that can be used outdoors for a long time. As a specific structure of the general solar cell module 31, as shown in FIG. 5, a transparent substrate 32 made of glass or the like, a surface side filler layer 33 made of a thermoplastic resin, and a photovoltaic element The solar battery cell 34, the back side filler layer 35 made of a thermoplastic resin, and a solar cell module backsheet 40 (hereinafter simply referred to as a backsheet) are laminated in this order and integrally formed. (See, for example, JP 2009-302361 A). The back-side filler layer 35 is formed of, for example, ethylene-vinyl acetate copolymer resin (EVA), and the back sheet 40 has a heat melting layer formed of a thermoplastic polyethylene resin. A resin layer 36 is provided. And in the said integral molding, generally the laminated body laminated | stacked as mentioned above is adhere | attached by the heating lamination method.

The heat-sealing resin layer 36 heat-fuses the back side filler layer 35 and the back sheet 40 by melting by heating and solidification by subsequent cooling. At this time, if the heat-sealing resin layer 35 flows excessively, problems such as leakage from the sheets, generation of wrinkles, thickness non-uniformity, and the like occur, leading to deterioration in quality. However, if the heating temperature is lowered to prevent these problems, sufficient fusion strength cannot be obtained. Therefore, a means for preventing such a problem is required.

JP 2009-302361 A

This invention is made | formed in view of such a situation, and aims at provision of the protective film for solar cell modules which can prevent the malfunction at the time of heat sealing | fusion, and a solar cell module using the same. .

The invention made to solve the above problems is
It has a heat-sealing resin layer,
This is a protective film for a solar cell module in which the synthetic resin, which is the main component of the heat-sealing resin layer, is crosslinked by electron beam irradiation.

The solar cell module protective film is bonded to the front surface side or the back surface side of the solar cell module by thermally fusing the heat sealing resin layer, and can protect the components of the solar cell module. And since the synthetic resin which is a main component of a heat-fusion resin layer has high heat resistance by being bridge | crosslinked by electron beam irradiation, it is suppressed that it flows too much at the time of heat-fusion. As a result, the solar cell module protective film can be easily and reliably filled, preventing problems such as leakage from the sheet of the heat-fusion resin layer during heat-fusion, generation of wrinkles, and uneven thickness. Can adhere to the agent layer.

The heat-sealing resin layer may contain a crosslinking agent. Thus, the crosslinking reaction at the time of electron beam irradiation can be enhanced by adding a crosslinking agent to the heat-sealing resin layer. In particular, when polypropylene is used for the heat-sealable resin layer, the addition of a cross-linking agent makes the cross-linking reaction of the polypropylene electron irradiation superior to the molecular cutting reaction, and heat resistance is maintained while maintaining the strength of the polypropylene. Can be raised.

When the heat sealing resin layer contains a crosslinking agent, the synthetic resin may be polypropylene. Thus, the intensity | strength of the said protective film for solar cell modules, heat resistance, etc. can be improved by making the main component of a heat-fusion resin layer into a polypropylene.

It is preferable that a pigment is dispersed and contained in the heat-sealing resin layer. Thus, the dispersion of the pigment in the heat-sealing resin layer can improve the heat resistance, thermal dimensional stability, weather resistance, strength, aging resistance, etc. of the protective film for solar cell module. it can.

The irradiation dose of the electron beam is preferably 5 kGy or more and 300 kGy or less. Thus, heat resistance can be raised, suppressing deterioration of a heat sealing | fusion resin layer by making irradiation dose of an electron beam into the said range.

The said protective film for solar cell modules is good to consist only of the said heat sealing | fusion resin layer. Since the heat-sealing resin layer is formed of a synthetic resin such as polyethylene or polypropylene having high strength and weather resistance, the solar cell module protective film has sufficient durability even if it is composed only of the heat-sealing resin layer. Can be demonstrated. Thus, by making it a single layer structure, manufacture of the said protective film for solar cell modules becomes easy, and it can reduce production cost.

When the protective film for a solar cell module is composed only of a heat-sealing resin layer, the average thickness of the heat-sealing resin layer is preferably 40 μm or more and 500 μm or less. Thus, by making the average thickness of the heat-sealing resin layer in the above range, the solar cell module can be reduced in weight, while providing sufficient strength, weather resistance, etc. to the protective film for the solar cell module, and withstand voltage. Therefore, it is possible to easily and reliably cope with the high voltage of the solar cell module.

The solar cell module protective film may be composed of only the heat-sealing resin layer, but may further include a hydrolysis-resistant layer on one surface side of the heat-sealing resin layer. Thus, by providing a hydrolysis-resistant layer on one surface side of the heat-sealing resin layer, the durability, weather resistance, and the like of the protective film for solar cell module can be dramatically improved. Moreover, the solar cell module which can be used suitably for a long time use outdoors is obtained by using the said protective film for solar cell modules excellent in durability, a weather resistance, etc. in this way.

It is preferable to further provide a gas barrier layer on one surface side of the heat sealing resin layer. Thus, by providing a gas barrier layer on the one surface side of the heat-sealing resin layer, gas barrier properties against oxygen, water vapor, and the like can be imparted to the protective film for a solar cell module. Moreover, the solar cell module which can be used suitably for a long time use outdoors is obtained by using the said protective film for solar cell modules which has gas barrier property in this way.

The solar cell module protective film may be used as a back sheet of the solar cell module. Thus, a photovoltaic cell can be protected easily and reliably by using the said protective film for solar cell modules as a solar cell module backsheet.

Another invention made to solve the above problems is as follows:
The protective film for the solar cell module;
A filler layer thermally fused to the surface of the protective film for the solar cell module;
Solar cells disposed in the filler layer;
A translucent substrate disposed on the surface of the filling layer.

In the solar cell module, since the synthetic resin constituting the heat-sealing resin layer of the protective film for solar cell modules is cross-linked by electron beam irradiation, between the sheets of the heat-sealing resin layer at the time of heat-sealing the protective film Problems such as leakage, wrinkles, and uneven thickness are prevented. Therefore, the solar cell module is excellent in productivity and quality.

Here, the “back surface” means the surface opposite to the light receiving surface of the solar cell module.

As described above, the solar cell module protective film of the present invention can prevent problems during heat fusion, and can improve the productivity and quality of the solar cell module.

It is typical sectional drawing which shows the protective film for solar cell modules which concerns on one Embodiment of this invention. It is typical sectional drawing which shows the protective film for solar cell modules which concerns on the form different from the protective film for solar cell modules of FIG. It is typical sectional drawing which shows the protective film for solar cell modules which concerns on the form different from the protective film for solar cell modules of FIG.1 and FIG.2. (A) is typical sectional drawing which shows the solar cell module using the protective film for solar cell modules of FIG. 1, (b) is a schematic diagram which shows the solar cell module using the protective film for solar cell modules of FIG. FIG. It is typical sectional drawing which shows the conventional common solar cell module.

Hereinafter, embodiments of the protective film for a solar cell module according to the present invention will be described in detail with reference to the drawings as appropriate. First, as a first embodiment of the present invention, a back sheet for a solar cell module (hereinafter sometimes referred to as a back sheet) shown in FIG. 1 and FIG.

[First embodiment]
The solar cell module protective film 1 of the first embodiment is composed of only the heat-sealing resin layer 3 formed in a sheet shape.

<Heat-fusion resin layer>
The heat-sealing resin layer 3 is a synthetic resin layer that melts when the solar cell module protective film 1 is heat-sealed to the back surface of the solar cell module.

The synthetic resin used for the heat-sealing resin layer 3 is not particularly limited, and for example, a synthetic resin mainly composed of an ethylene-based polymer or polypropylene can be used. Examples of the ethylene polymer include polyethylene such as low density polyethylene, medium density polyethylene and high density polyethylene, ethylene-α olefin copolymer, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene- (meta ) Acrylic acid copolymer, an ionic cross-linked product of ethylene- (meth) acrylic acid copolymer, ethylene-vinyl ester copolymer, and the like can be used. Among these, it has excellent adhesion to an ethylene vinyl acetate copolymer (EVA) usually used for a filler layer of a solar cell module, has good hydrolysis resistance, and is crosslinked by electron beam irradiation. Polyethylene which proceeds predominantly is preferred. Moreover, when adding the below-mentioned crosslinking agent to a heat sealing | fusion resin layer, the polypropylene excellent in intensity | strength, heat resistance, etc. is preferable. In polypropylene, the molecular cleavage reaction at the time of electron irradiation is dominant over the crosslinking reaction, so the strength etc. deteriorates if electron irradiation is performed as it is, but the strength etc. is maintained by adding a crosslinking agent and performing electron irradiation. The heat resistance can be increased as it is. In addition, the said synthetic resin can also be used individually by 1 type, and can also use 2 or more types together.

A polymer obtained by copolymerizing a compound having a reactive functional group such as a glycidyl group, a silanol group, or an amino group with the ethylene polymer can be used for the heat-sealing resin layer 3. Moreover, a photopolymerization initiator can be added to the ethylene polymer to impart photopolymerizability. As this photopolymerization initiator, for example, a hydrogen abstraction type or an internal cleavage type can be used.

As the hydrogen abstraction type (bimolecular reaction type) photopolymerization initiator, for example, benzophenone, methyl orthobenzoylbenzoate, 4-benzoyl-4'-methyldiphenyl sulfide, isopropylthioxanthone and the like can be used.

As the internal cleavage type photopolymerization initiator, for example, benzoin alkyl ether, benzyl dimethyl ketal or the like can be used. Further, α-hydroxyalkylphenone type polymerization initiators such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, alkylphenylglyoxylate, diethoxyacetophenone, 2-methyl Α-aminoalkylphenone type such as -1- [4- (methylthio) phenyl] -2-morpholinopropane-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 A polymerization initiator, an acyl phosphine oxide, etc. can be used.

The synthetic resin constituting the heat-sealing resin layer 3 is cross-linked by electron beam irradiation. By irradiation with an electron beam, the molecules of the synthetic resin are cross-linked, and heat resistance and the like are increased. In addition, a well-known thing can be used as an apparatus which irradiates an electron beam.

The lower limit of the electron beam irradiation dose is preferably 5 Gy, more preferably 10 Gy. On the other hand, the upper limit of the electron beam irradiation dose is preferably 300 Gy, more preferably 200 Gy. When the irradiation dose is less than the above lower limit, the synthetic resin is not sufficiently cross-linked, and the effect of increasing the heat resistance may not be obtained. Conversely, when the irradiation dose exceeds the above upper limit, the synthetic resin is deteriorated, and the strength, life, etc. of the heat-sealing resin layer 3 may be reduced.

The lower limit of the acceleration voltage of the electron beam is preferably 10 kV, more preferably 50 kV. On the other hand, the upper limit of the acceleration voltage of the electron beam is preferably 500 kV, more preferably 400 kV. When the acceleration voltage is less than the above lower limit, the synthetic resin is not sufficiently cross-linked, and the effect of increasing the heat resistance may not be obtained. On the other hand, when the acceleration voltage exceeds the above upper limit, the penetrating power of the electron beam becomes strong, which may cause damage to other members and the manufacturing apparatus.

It is preferable that a cross-linking agent is added to the heat-sealing resin layer 3 in order to enhance the cross-linking reaction during electron beam irradiation.

The cross-linking agent is not particularly limited as long as it can exhibit a cross-linking reaction between molecules by electron beam irradiation, and a known polyfunctional monomer generally used as a cross-linking agent can be used. It is preferable to use a functional monomer. Examples of the allyl polyfunctional monomer include triallyl isocyanurate (TAIC), triallyl cyanurate, and trimethallyl isocyanurate. Among these, TAIC is particularly preferable. Two or more kinds of the allylic polyfunctional monomers may be used.

As a minimum of content of a crosslinking agent, 1 mass% is preferable and 1.5 mass% is more preferable. On the other hand, as an upper limit of content of a crosslinking agent, 30 mass% is preferable and 20 mass% is more preferable. When the content of the crosslinking agent is less than the above range, a sufficient crosslinking effect may not be obtained. On the other hand, when the content of the crosslinking agent exceeds the above range, the quality of the synthetic resin may be deteriorated or molding may be difficult.

The heat-sealing resin layer 3 may contain a pigment in a dispersed manner. Although it does not specifically limit as this pigment, The white pigment which can provide light diffusibility is preferable.

As the white pigment, for example, calcium carbonate, titanium oxide, zinc oxide, lead carbonate, barium sulfate and the like can be used. Among these, titanium oxide is preferable because it is excellent in dispersibility in the resin material forming the synthetic resin layer and has a relatively large effect of improving whiteness and solar reflectance.

Non-white pigments include black pigments such as carbon black and black iron oxide, blue pigments such as ultramarine and bitumen, red pigments such as red bean (iron oxide red), cadmium red, and molybdenum orange, and metals that give metallic luster. A powder pigment etc. are mentioned, The designability of a solar cell module can be improved by carrying out dispersion | distribution containing of these pigments in the heat-fusion resin layer 3. FIG.

The lower limit of the average particle diameter of the pigment is preferably 100 nm, and more preferably 300 nm. On the other hand, as an upper limit, 30 micrometers is preferable and 3 micrometers is more preferable. When the average particle diameter of the pigment is less than the above lower limit, uniform dispersion in the heat-sealing resin layer 3 may be difficult due to aggregation or the like. On the contrary, when the average particle diameter exceeds the above upper limit, the effect of improving various properties such as heat resistance to the heat-sealing resin layer 3 may be reduced.

The lower limit of the pigment content is preferably 3% by mass, and more preferably 5% by mass. On the other hand, as an upper limit, 30 mass% is preferable and 20 mass% is more preferable. When the pigment content is less than the above lower limit, the effect of improving the durability, heat resistance, strength, etc. of the heat sealing resin layer 3 may be reduced. On the contrary, when the pigment content exceeds the above upper limit, the dispersibility of the pigment in the heat-sealing resin layer 3 is lowered, and the strength of the heat-sealing resin layer 3 may be lowered.

Furthermore, for the purpose of improving and modifying the handling property, heat resistance, weather resistance, thermal dimensional stability, mechanical properties, etc., the heat-sealing resin layer 3 is provided with, for example, a heat-resistant agent, an antioxidant, and an ultraviolet ray inhibitor. Various additives such as an antistatic agent, a solvent, a lubricant, a filler, a reinforcing fiber, a reinforcing agent, a flame retardant, a flame retardant, a foaming agent, and an antifungal agent can be appropriately mixed.

Examples of the heat-resistant agent include aromatic amine-based antioxidants, hindered phenol-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like. The above can be used.

The molding method of the heat-sealing resin layer 3 is not particularly limited, and a known method such as an extrusion method such as a T-die method or an inflation method, a cast molding method, or a cutting method is employed.

The lower limit of the thickness (average thickness) of the heat sealing resin layer 3 is preferably 40 μm, and more preferably 50 μm. On the other hand, the upper limit of the thickness of the heat-sealing resin layer 3 is preferably 500 μm, and more preferably 300 μm. When the thickness of the heat-sealing resin layer 3 is less than the above lower limit, the solar electronic module is protected in addition to the possibility of insufficient bonding between the solar cell module protective film 1 and the solar cell module filler layer. Therefore, the strength, weather resistance, voltage resistance, etc. may not be sufficiently exhibited. On the contrary, when the thickness of the heat-sealing resin layer 3 exceeds the upper limit, the flexibility of the protective film 1 for the solar cell module is reduced, and further, the solar cell module is required to be thin and light. It will be contrary.

When the protective film 1 for the solar cell module is bonded to the front surface side or the back surface side of the solar cell module by heating lamination, the synthetic resin that is the main component of the heat-sealing resin layer 3 is crosslinked by electron beam irradiation. Therefore, excessive flow is suppressed. As a result, the protective film 1 for the solar cell module prevents problems such as leakage from the sheet of the heat sealing resin layer 3 during heat sealing, generation of wrinkles, thickness non-uniformity, and the like easily and reliably. It can be adhered to the filler layer.

<Solar cell module 21>
The solar cell module 21 in FIG. 4 (a) includes a protective film 1 for the solar cell module, filler layers 22 and 24 thermally fused to the surface of the protective film 1 for the solar cell module, and the filler layer. Solar cell 23 disposed between 22 and 24, and translucent substrate 25 disposed on the surface of filler layer 24.

The translucent substrate 25 is laminated on the outermost surface, and has (a) transparency to sunlight and electrical insulation, (b) mechanical, chemical and physical strength, specifically Is excellent in weather resistance, heat resistance, durability, water resistance, gas barrier against water vapor, wind pressure resistance, chemical resistance, fastness, etc., and (c) high surface hardness and surface dirt, dust, etc. It is required to have excellent antifouling properties for preventing accumulation.

As the material for forming the translucent substrate 25, glass or synthetic resin is used. Synthetic resins used for the translucent substrate 25 include, for example, polyethylene resins, polypropylene resins, cyclic polyolefin resins, fluorine resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), and acrylonitrile. Butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, various nylons, etc. Polyamide resin, polyimide resin, polyamideimide resin, polyaryl phthalate resin, silicone resin, polyphenylene sulfide resin, polysulfone resin, acetal resin, polyethersulfone resin, polyurethane resin Fat, and cellulosic resins. Among these resins, fluorine resins, cyclic polyolefin resins, polycarbonate resins, poly (meth) acrylic resins, or polyester resins are particularly preferable.

When a synthetic resin is used for the light-transmitting substrate 25, a transparent vapor deposition film of an inorganic oxide such as silicon oxide or aluminum oxide is laminated on one surface by the PVD method or the CVD method for the purpose of improving gas barrier properties. For the purpose of improving and improving processability, heat resistance, weather resistance, mechanical properties, dimensional stability, etc., for example, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, antistatic agents, light stabilizers It is also possible to contain various additives such as fillers, reinforcing fibers, reinforcing agents, flame retardants, flame retardants, foaming agents, fungicides, and pigments.

The thickness (average thickness) of the translucent substrate 25 is not particularly limited, and is appropriately selected depending on the material to be used so as to have required strength, gas barrier properties, and the like. The thickness of the synthetic resin translucent substrate 25 is preferably, for example, 6 μm to 300 μm, and more preferably 9 μm to 150 μm. Further, the thickness of the glass translucent substrate 25 is generally about 3 mm.

The filler layer 22 and the filler layer 24 are filled around the solar battery cell 23, and have scratch resistance, shock absorption, and the like for protecting the solar battery cell 23. In addition, the filler layer 24 laminated | stacked on the surface of the photovoltaic cell 23 has transparency which permeate | transmits sunlight in addition to the said various functions.

Examples of the material for forming the filler layer 22 and the filler layer 24 include fluorine resin, ethylene vinyl acetate copolymer resin (EVA), ionomer resin, ethylene-acrylic acid or methacrylic acid copolymer, polyethylene resin, polypropylene resin, Examples include acid-modified polyorene fin-based resins obtained by modifying polyolefin-based resins such as polyethylene with unsaturated carboxylic acids such as acrylic acid, polyvinyl butyral resins, silicone-based resins, epoxy-based resins, and (meth) acrylic resins. Among these synthetic resins, fluorine resins, ethylene vinyl acetate copolymer resins (EVA), or silicone resins that are excellent in weather resistance, heat resistance, gas barrier properties, and the like are preferable.

Examples of the material for forming the filler layer 22 and the filler layer 24 include a thermoreversible crosslinkable olefin polymer composition disclosed in JP-A No. 2000-34376, specifically, (a) an unsaturated carboxylic acid anhydride. Modified olefin polymer modified with a product and an unsaturated carboxylic acid ester, wherein the average number of carboxylic anhydride groups per molecule is one or more, and the carboxylic acid in the modified olefin polymer A modified olefin polymer in which the ratio of the number of carboxylic acid ester groups to the number of acid anhydride groups is 0.5 to 20, and (b) a hydroxyl group-containing polymer having an average number of hydroxyl groups per molecule of 1 or more. Also, those having a ratio of the number of hydroxyl groups of component (b) to the number of carboxylic anhydride groups of component (a) of 0.1 to 5 are used.

For the purpose of improving the weather resistance, heat resistance, gas barrier properties, etc., the forming material of the filler layer 22 and the filler layer 24 is, for example, a crosslinking agent, a thermal antioxidant, a light stabilizer, an ultraviolet absorber, a light absorber, and the like. Various additives such as an antioxidant can be appropriately contained. In addition, the thickness (average thickness) of the filler layer 22 and the filler layer 24 is not particularly limited, but is preferably 200 μm or more and 1000 μm or less, and more preferably 350 μm or more and 600 μm or less.

The solar battery cell 23 is a photovoltaic element that converts light energy into electrical energy, and is disposed between the filler layer 22 and the filler layer 24. The plurality of solar cells 23 are laid in substantially the same plane, and are wired in series or in parallel although not shown. Examples of the solar battery cell 23 include a crystalline silicon solar electronic element such as a single crystal silicon type solar cell element and a polycrystalline silicon type solar cell element, an amorphous silicon solar cell element having a single junction type or a tandem structure type, and gallium arsenide. Group 3 to 5 compound semiconductor solar electronic devices such as (GaAs) and indium phosphorus (InP), and Group 2 to 6 compound semiconductor solar electronic devices such as cadmium tellurium (CdTe) and copper indium selenide (CuInSe ₂ ) Etc., and those hybrid elements can also be used. Note that the filler layer 22 and the filler layer 24 are also filled between the plurality of solar battery cells 23 without any gap.

<Method for Manufacturing Solar Cell Module 21>
Although it does not specifically limit as a manufacturing method of the said solar cell module 21, Generally, it has the following processes.
(A) The process of laminating | stacking the filler layer 24, the photovoltaic cell 23, the filler layer 22, and the said protective film 1 for said solar cell modules in this order (B) The said laminated body is integrated and heated by vacuum suction Integrated molding process by vacuum heating lamination method etc.

The lower limit of the heating temperature in the vacuum heating lamination method is preferably 100 ° C, more preferably 120 ° C. On the other hand, as an upper limit of heating temperature, 200 degreeC is preferable and 180 degreeC is more preferable. When the heating temperature is less than the above lower limit, the heat-sealing resin layer 3 is not sufficiently melted, and there is a possibility that adhesion to the filler layer 22 is not sufficiently performed. On the other hand, when the heating temperature exceeds the above upper limit, the heat-sealing resin layer 3 and other layers of the solar cell module 21 may be deteriorated.

Moreover, in the manufacturing method of the said solar cell module 21, for the purpose of the adhesiveness etc. between the photovoltaic cell 23, the filler layer 22, and the filler layer 24, for example, a hot melt adhesive, a solvent type adhesive, Apply photo-curing adhesive, etc., or apply corona discharge treatment, ozone treatment, low temperature plasma treatment, glow discharge treatment, oxidation treatment, primer coating treatment, undercoat treatment, anchor coating treatment, etc. Is possible.

As described above, the solar cell module 21 has high heat resistance when the heat-sealing resin layer 3 of the protective film 1 for solar cell module is irradiated with an electron beam to the synthetic resin as a main component. Thereby, the solar cell module 21 prevents inconveniences such as leakage from the sheets of the heat-sealing resin layer 3, generation of wrinkles, thickness non-uniformity, etc. during vacuum heating lamination in the above manufacturing method, It can be easily and reliably bonded to the filler layer 22. As a result, the solar cell module 21 has high productivity and quality.

[Second Embodiment]
Next, a solar cell module backsheet according to a different embodiment from that shown in FIG. 1 and FIG. In the protective film 11 for solar cell module shown in FIG. 2, the heat-sealing resin layer 3 and the hydrolysis-resistant layer 13 are laminated in this order from the surface side (light receiving side).

Since the heat-sealing resin layer 3 is the same as the solar cell module protective film 1 of FIG. 1 described above, the same reference numerals are given and description thereof is omitted.

However, the thickness (average thickness) of the heat-sealing resin layer 3 can be made thinner than that used for the protective film 1 for solar cell modules in FIG. As a minimum of the thickness of the heat sealing | fusion resin layer 3, 10 micrometers is preferable and 50 micrometers is more preferable. On the other hand, the upper limit of the thickness of the heat-sealing resin layer 3 is preferably 400 μm, and more preferably 300 μm.

<Hydrolysis resistant layer>
The hydrolysis-resistant layer 13 is formed with a synthetic resin as a main component. Examples of the synthetic resin as the main component of the hydrolysis-resistant layer 13 include hydrolysis-resistant polyethylene terephthalate, polyethylene naphthalate (PEN), vinyl fluoride resin (PVF), and vinylidene fluoride resin that are excellent in hydrolysis resistance and heat resistance. Fluorine resin such as (PVDF) or a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE) can be used.

The hydrolysis-resistant polyethylene terephthalate is polyethylene terephthalate whose hydrolysis resistance is improved by, for example, reducing the content of low-molecular impurities (oligomers).

The polyethylene naphthalate is a polyester resin having ethylene naphthalate as a main repeating unit, and is synthesized with naphthalenedicarboxylic acid as a main dicarboxylic acid component and ethylene glycol as a main glycol component.

The ethylene naphthalate unit is preferably 80 mol% or more of all repeating units of the polyester. If the proportion of ethylene naphthalate units is less than 80 mol%, the hydrolysis resistance, strength, and barrier properties of polyethylene naphthalate may be reduced.

Examples of the naphthalenedicarboxylic acid include 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, and the like. In view of surface, 2,6-naphthalenedicarboxylic acid is particularly preferred.

The terminal carboxyl group amount of polyethylene naphthalate is preferably 10 eq / T (equivalent / 106 g) or more and 40 eq / T or less, more preferably 10 eq / T or more and 30 eq / T or less, and further preferably 10 eq / T or more and 25 eq / T or less. When the amount of the terminal carboxyl group is less than the above lower limit, the productivity may decrease. On the other hand, when the amount of the terminal carboxyl group exceeds the above upper limit, the effect of improving the hydrolysis resistance by the carbodiimide compound may be decreased.

In addition, the manufacturing method of polyethylene naphthalate is not particularly limited, and various known methods such as a transesterification method and a direct esterification method can be employed.

The hydrolysis-resistant layer 13 may contain a carbodiimide compound in the main component synthetic resin. Thus, by containing a carbodiimide compound, the hydrolysis resistance of the hydrolysis-resistant layer 13 is remarkably improved. As content of this carbodiimide compound, 0.1 mass% or more and 10 mass% or less are preferable, and 0.5 mass% or more and 3 mass% or less are more preferable. Thus, by making content of a carbodiimide compound into the said range, the hydrolysis resistance of the hydrolysis-resistant layer 13 can be improved effectively.

As this carbodiimide compound, for example, (a) N, N′-diphenylcarbodiimide, N, N′-diisopropylphenylcarbodiimide, N, N′-dicyclohexylcarbodiimide, 1,3-diisopropylcarbodiimide, 1- (3-dimethylaminopropyl) And monocarbodiimides such as 3-ethylcarbodiimide, and (b) polycarbodiimide compounds such as poly (1,3,5-triisopropylphenylene-2,4-carbodiimide). Among these, N, N′-diphenylcarbodiimide and N, N′-diisopropylphenylcarbodiimide are preferable, and the hydrolysis resistance of the hydrolysis-resistant layer 13 can be further improved. Further, the molecular weight of the carbodiimide compound is preferably in the range of 200 to 1000, particularly in the range of 200 to 600. When the molecular weight is less than the above lower limit, the scattering property of the carbodiimide compound may increase, and when the molecular weight exceeds the upper limit, the dispersibility of the carbodiimide compound in the resin may decrease.

Further, the hydrolysis-resistant layer 13 may contain an antioxidant in addition to the carbodiimide compound in the synthetic resin that is the main component. Thus, by including both a carbodiimide compound and antioxidant in a synthetic resin, the said hydrolysis resistance improves markedly, Furthermore, decomposition | disassembly of a carbodiimide compound can also be suppressed. As content of this antioxidant, 0.05 mass% or more and 1 mass% or less are preferable, and 0.1 mass% or more and 0.5 mass% or less are more preferable. When the content of the antioxidant is less than the above lower limit, the carbodiimide degradation inhibiting function and the hydrolysis resistance may be reduced. When the content of the antioxidant exceeds the above upper limit, the hydrolysis resistant layer There is a possibility that the color tone of 13 is impaired. Specifically, as the antioxidant, hindered phenol compounds and thioether compounds, particularly hindered phenol compounds, are preferable, and the hydrolysis resistance of the hydrolysis resistant layer 13 can be effectively improved. . The mass ratio of the antioxidant content to the carbodiimide compound content is preferably 0.1 or more and 1.0 or less, and more preferably 0.15 or more and 0.8 or less. If this mass ratio is less than the above lower limit, the effect of suppressing hydrolysis of carbodiimide itself may be insufficient. On the other hand, if this mass ratio exceeds the above upper limit, the effect of suppressing hydrolysis of carbodiimide will peak. become. In addition, the addition method of a carbodiimide compound and antioxidant may be a method of kneading to a synthetic resin or a method of adding to a polycondensation reaction of a synthetic resin.

Further, the hydrolysis-resistant layer 13 may contain an aromatic polyester in addition to the main component synthetic resin. By containing the aromatic polyester in the hydrolysis-resistant layer 13 as described above, the knot strength, the delamination resistance, the mechanical strength, and the like can be improved while maintaining the hydrolysis resistance of the hydrolysis-resistant layer 13. it can. As content of this aromatic polyester, 1 to 10 mass% is preferable. By setting the content of the aromatic polyester within the above range, knot strength, delamination resistance, mechanical strength, and the like can be effectively improved. Specifically, the aromatic polyester is preferably a polyester obtained by copolymerizing a terephthalic acid component and 4,4'-diphenyldicarboxylic acid as a main dicarboxylic acid component and ethylene glycol as a main glycol component.

The hydrolysis-resistant layer 13 may contain a pigment in a dispersed manner. Although it does not specifically limit as this pigment, The white pigment which can provide light diffusibility is preferable. The type, content, etc. of the white pigment can be the same as those of the heat-sealing resin layer 3.

Further, the forming method of the hydrolysis-resistant layer 13 and the additives in the forming material of the hydrolysis-resistant layer 13 can be the same as those of the heat-sealing resin layer 3.

The lower limit of the thickness (average thickness) of the hydrolysis-resistant layer 13 is preferably 12 μm, and more preferably 20 μm. On the other hand, the upper limit of the thickness of the hydrolysis-resistant layer 13 is preferably 300 μm, and more preferably 200 μm. When the thickness of the hydrolysis-resistant layer 13 is less than the above lower limit, the durability improving effect of the hydrolysis-resistant layer 13 may not be sufficiently exhibited and handling may be difficult. On the other hand, when the thickness of the hydrolysis-resistant layer 13 exceeds the above upper limit, it is contrary to the demand for thinning and lightening the solar cell module.

In addition, about the thickness of the heat-fusion resin layer 3 and the hydrolysis-resistant layer 13, for example, the heat-fusion resin layer 3 is 200 μm or more, and the thickness of the hydrolysis-resistant layer 13 is 100 μm or less. You may enlarge the ratio for 3 to the said protective film 11 for solar cell modules. Conversely, for example, the thickness of the hydrolysis-resistant layer 13 is set to 180 μm or more, and the thickness of the heat-sealing resin layer 3 is set to 100 μm or less, so that the proportion of the hydrolysis-resistant layer 13 in the protective film 11 for solar cell modules is increased. May be.

As a method for laminating the hydrolysis-resistant layer 13 to the heat fusion resin layer 3, a known method can be appropriately employed. For example, the hydrolysis-resistant layer 13 can be provided by directly laminating the heat-sealing resin layer 3 by a T-die method using a coextrusion method or the like. Alternatively, the hydrolysis-resistant layer 13 may be separately formed into a film and then bonded and laminated on the surface of the heat-sealing resin layer 3 with an adhesive. Thus, when it adhere | attaches via an adhesive agent, with the adhesive bond layer formed between the heat-fusion resin layer 3 and the hydrolysis-resistant layer 13, the impact resistance of the said protective film 11 for solar cell modules, durability Property, fastness, etc. can be improved.

As an adhesive for adhering the heat-sealing resin layer 3 and the hydrolysis-resistant layer 13, a laminating adhesive or a melt-extruded resin is used. Examples of the laminating adhesive include dry laminating adhesive, wet laminating adhesive, hot melt laminating adhesive, non-solvent laminating adhesive, and the like. Among these laminating adhesives, a dry laminate having excellent adhesive strength, durability, weather resistance, etc., and a function of sealing and protecting defects (such as scratches, pinholes, recesses, etc.) such as the hydrolysis-resistant layer 13. Especially preferred are adhesives.

Examples of the adhesive for dry laminate include, for example, polyvinyl acetate adhesive, homopolymers such as ethyl acrylate, butyl, 2-ethylhexyl ester, and copolymers thereof with methyl methacrylate, acrylonitrile, styrene, etc. Polyacrylate adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives made of copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc., cellulose Adhesive, polyester adhesive, polyamide adhesive, polyimide adhesive, urea resin, melamine resin, amino resin adhesive, phenol resin adhesive, epoxy adhesive, polyurethane adhesive, reactive type (Meth) acrylic adhesive, chloroprene rubber, nitrile rubber , Styrene - butadiene made of rubber or the like rubber adhesive, a silicone-based adhesive, an alkali metal silicate, inorganic adhesive or the like made of a low-melting glass. Among these adhesives for dry laminating, a polyurethane system in which a decrease in adhesion strength and delamination due to long-term outdoor use of the protective film 11 for solar cell modules is prevented, and deterioration such as yellowing is further reduced. Adhesives, particularly polyester urethane adhesives are preferred. The curing agent is preferably an aliphatic polyisocyanate with little thermal yellowing.

Examples of the melt-extruded resin include a polyethylene resin, a polypropylene resin, an acid-modified polyethylene resin, an acid-modified polypropylene resin, an ethylene-acrylic acid or methacrylic acid copolymer, a Surlyn resin, and an ethylene-vinyl acetate copolymer. One type or two or more types of thermoplastic resins such as a polymer, a polyvinyl acetate resin, an ethylene-acrylic acid ester or a methacrylic acid ester copolymer, a polystyrene resin, and a polyvinyl chloride resin can be used. In addition, when adopting the extrusion laminating method using the above melt-extruded resin, in order to obtain stronger adhesive strength, the above-described anchor coat treatment is performed on the lamination facing surface of the film (or layer) laminated via the adhesive. A surface treatment such as the above may be performed.

As a minimum of the amount of lamination of the above-mentioned adhesive (solid content conversion), 1 g / m ² is preferred and 3 g / m ² is especially preferred. On the other hand, as an upper limit of the lamination amount of the adhesive, 20 g / m ² is preferable, and 15 g / m ² is particularly preferable. When the amount of the adhesive layered is less than the above lower limit, the adhesive strength and the defect sealing function may not be obtained. On the other hand, when the lamination amount of the adhesive exceeds the above upper limit, the lamination strength and durability may be lowered.

In addition, in the adhesive for laminating or the melt-extruded resin, for the purpose of improving and modifying handling properties, heat resistance, weather resistance, mechanical properties, etc., for example, a solvent, a lubricant, a crosslinking agent, an antioxidant, Various additives such as an antistatic agent, a filler, a reinforcing fiber, a reinforcing agent, a flame retardant, a flame retardant, a foaming agent, an antifungal agent, and a pigment can be appropriately mixed.

The solar cell module protective film 11 can be heat-sealed to the filler layer of the solar cell module easily and reliably as in the solar cell module protective film 1 of FIG. Moreover, since the said protective film 11 for solar cell modules is equipped with the hydrolysis-resistant layer 13, it exhibits high durability and a weather resistance.

[Third embodiment]
Next, the back sheet for a solar cell module according to the embodiment shown in FIGS. 1 and 4A and FIG. 2 shown in FIGS. 3 and 4B will be described. In the protective film 111 for solar cell module shown in FIG. 3, the heat sealing resin layer 3, the gas barrier layer 12, and the hydrolysis resistant layer 13 are laminated in this order from the surface side (light receiving side).

Since the heat-sealing resin layer 3 and the hydrolysis-resistant layer 13 are the same as the solar cell module protective film 11 shown in FIG. 2, the same reference numerals are given and description thereof is omitted.

<Gas barrier layer>
The gas barrier layer 12 is a layer having a function of reducing permeation of gas such as hydrogen gas and oxygen gas. The gas barrier layer 12 includes a base film and an inorganic oxide layer laminated on the base film.

The base film of the gas barrier layer 12 is formed with a synthetic resin as a main component. Examples of the main component synthetic resin of the base film include polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer. (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, Examples include silicone resins, polysulfone resins, polyphenylene sulfide resins, polyether sulfone resins, polyurethane resins, acetal resins, and cellulose resins. Among these, polyethylene terephthalate having a good balance between various functions such as heat resistance and weather resistance and price is particularly preferable. In addition, the method for forming the base film, the additive in the base film forming material, and the like can be the same as those of the heat-sealing resin layer 3.

The lower limit of the thickness (average thickness) of the base film is preferably 7 μm and more preferably 10 μm. On the other hand, as an upper limit of the thickness of a base film, 20 micrometers is preferable and 15 micrometers is more preferable. When the thickness of the base film is less than the above lower limit, there is a possibility that inconveniences such as curling easily occur during vapor deposition for forming the inorganic oxide layer, and handling becomes difficult. . On the other hand, when the thickness of the base film exceeds the above upper limit, it is contrary to the demand for thinning and lightening of the solar cell module.

The inorganic oxide layer is a layer for expressing gas barrier properties against oxygen, water vapor, and the like, and is formed by depositing an inorganic oxide on the back surface of the base film. The vapor deposition means for forming this inorganic oxide layer is not particularly limited as long as the inorganic oxide can be vapor deposited on the synthetic resin base film without causing deterioration such as shrinkage and yellowing. (A) Physical vapor deposition methods (Physical Vapor Deposition method; PVD method) such as vacuum deposition method, sputtering method, ion plating method, ion cluster beam method, (b) Plasma chemical vapor deposition method, thermal chemical vapor deposition method, A chemical vapor deposition method (Chemical Vapor Deposition method; CVD method) such as a photochemical vapor deposition method is employed. Among these vapor deposition methods, a vacuum vapor deposition method and an ion plating method that can form a high-quality inorganic oxide layer with high productivity are preferable.

The inorganic oxide constituting the inorganic oxide layer is not particularly limited as long as it has gas barrier properties. For example, aluminum oxide, silica oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, magnesium oxide Among them, aluminum oxide or silica oxide having a good balance between gas barrier properties and price is particularly preferable.

The lower limit of the thickness (average thickness) of the inorganic oxide layer is preferably 3 mm, more preferably 400 mm. On the other hand, the upper limit of the thickness of the inorganic oxide layer is preferably 3000 mm, more preferably 800 mm. When the thickness of the inorganic oxide layer is less than the above lower limit, the gas barrier property may be lowered. On the other hand, when the thickness of the inorganic oxide layer exceeds the above upper limit, the flexibility of the inorganic oxide layer is reduced, and defects such as cracks are likely to occur.

The inorganic oxide layer may have a single layer structure or a multilayer structure of two or more layers. By making the inorganic oxide layer into a multilayer structure in this way, the deterioration of the base film is reduced by reducing the thermal burden applied during vapor deposition, and the adhesion between the base film and the inorganic oxide layer is further improved. can do. The vapor deposition conditions in the physical vapor deposition method and the chemical vapor deposition method are appropriately designed according to the resin type of the base film, the thickness of the inorganic oxide layer, and the like.

Also, in order to improve the close adhesion between the base film and the inorganic oxide layer, the surface of the base film is preferably subjected to a surface treatment. Examples of such adhesion improving surface treatment include (a) corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, and the like ( b) Primer coat treatment, undercoat treatment, anchor coat treatment, vapor deposition anchor coat treatment and the like. Among these surface treatments, corona discharge treatment and anchor coat treatment that improve adhesion strength with the inorganic oxide layer and contribute to the formation of a dense and uniform inorganic oxide layer are preferable.

Examples of the anchor coating agent used for the anchor coating treatment include a polyester anchor coating agent, a polyamide anchor coating agent, a polyurethane anchor coating agent, an epoxy anchor coating agent, a phenol anchor coating agent, and a (meth) acrylic anchor coating. Agents, polyvinyl acetate anchor coating agents, polyolefin anchor coating agents such as polyethylene aly polypropylene, and cellulose anchor coating agents. Among these anchor coating agents, polyester anchor coating agents that can further improve the adhesive strength between the base film and the inorganic oxide layer are particularly preferable.

The lower limit of the coating amount of the anchor coating agent (in terms of solid content), preferably from ^{^{0.1g / m 2, 1g / m}} 2 is more preferable. In contrast, the upper limit of the amount of coating of the anchor coating agent is preferably ^{^{5g / m 2, 3g / m}} 2 is more preferable. When the coating amount of the anchor coating agent is less than the above lower limit, the effect of improving the adhesion between the base film and the inorganic oxide layer may be reduced. On the other hand, when the coating amount of the anchor coating agent exceeds the above upper limit, the strength, durability, etc. of the gas barrier layer 12 may be lowered.

In addition, in the above-mentioned anchor coating agent, there are various silane coupling agents for improving adhesion, anti-blocking agents for preventing blocking with a base film, ultraviolet absorbers for improving weather resistance, etc. Additives can be mixed as appropriate. The mixing amount of the additive is preferably 0.1% by weight or more and 10% by weight or less from the balance between the effect expression of the additive and the function inhibition of the anchor coat agent.

The said protective film 111 for solar cell modules can be obtained by forming each layer which comprises the said protective film 111 for said solar cell modules, and adhere | attaching and laminating | stacking these layers using the above-mentioned adhesive agent, for example. it can. Moreover, the protective film 111 for solar cell modules can also be manufactured using the method of apply | coating and laminating | stacking the composition of another layer on the back surface of a certain layer, without using an adhesive agent.

The solar cell module protective film 111 can be easily and reliably heat-sealed to the solar cell module filler layer in the same manner as the solar cell module protective film 1 shown in FIG. Moreover, since the said protective film 111 for solar cell modules is provided with the gas barrier layer 12, it has high gas barrier property with respect to oxygen, water vapor | steam, etc.

<Solar cell module 121>
The solar cell module 121 of FIG. 4 (b) includes the solar cell module protective film 111, the filler layers 22 and 24 thermally bonded to the surface of the solar cell module protective film 111, and the filler layer. Solar cell 23 disposed between 22 and 24, and translucent substrate 25 disposed on the surface of filler layer 24.

The solar cell module 121 can easily and reliably heat-fuse the heat-sealing resin layer 3 of the solar cell module protective film 111 to the filler layer 22 as described above. Since the solar cell module 121 includes the gas barrier layer 12, the gas barrier property against oxygen, water vapor, and the like is improved, and the solar cell module 121 can be suitably used for outdoor use for a long time. In addition, since the solar cell module 121 includes the hydrolysis-resistant layer 13 and durability and weather resistance are improved, the solar cell module 121 can be suitably used for a roof-standing solar cell module.

[Other Embodiments]
The protective film for solar cell modules and the solar cell module of the present invention are not limited to the above embodiment. For example, the protective film for the solar cell module is formed by laminating other layers (synthetic resin layer, metal layer, inorganic oxide layer, etc.) and film in addition to the heat fusion resin layer, the gas barrier layer, and the hydrolysis resistant layer. Also good. Thus, by laminating | stacking another layer or film, various characteristics, such as the voltage resistance of the said solar cell module protective film, gas-barrier property, a weather resistance, and durability, can be improved significantly.

Further, in order to improve the degree of crosslinking of the heat-sealing resin layer, for example, an organic peroxide, a silane coupling agent or the like may be added to the forming material.

As the organic peroxide, it is preferable to employ one having a decomposition temperature of 145 ° C. or less with a half-life of 10 hours from the viewpoint of reactivity. Examples of the organic peroxide having a half-life decomposition time of 10 hours and a temperature of 145 ° C. or less include dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, Benzoyl peroxide, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, 1,1 -Di (t-amylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-amylperoxy) cyclohexane, t-amylperoxyisononanoate, t-amylperoxynormal octoate 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-butyl) Peroxy) cyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-amyl-peroxybenzoate, t -Butylperoxyacetate, t-butylperoxyisononanoate, t-butylperoxybenzoate, n-butyl-4,4-di- (t-butylperoxy) valerate, di (2-t-butylperoxy) Propyl) benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl- Use 2,5-di (t-butylperoxy) hexyne-3, etc. It can be. These organic peroxides can be used alone or in combination of two or more.

The compounding amount of the organic peroxide is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the synthetic resin. If the amount of the organic peroxide is less than the above lower limit, the formation of a crosslinked structure may be insufficient. On the other hand, when the compounding amount of the organic peroxide exceeds the above upper limit, the synthetic resin may be deteriorated due to decomposition due to excessive reaction or the like.

Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- Glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane or the like can be used.

The blending amount of the silane coupling agent is preferably 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the synthetic resin. If the blending amount of the silane coupling agent is smaller than the above lower limit, the adhesiveness may be lowered. On the other hand, if the amount of the silane coupling agent exceeds the upper limit, sufficient heat resistance and weather resistance may not be obtained.

In the above embodiment, an inorganic oxide layer is deposited on a base film to form a gas barrier film, and this gas barrier film is laminated with other layers. You may form a gas barrier layer by vapor-depositing directly on the surface etc. of a hydrolysis-resistant layer. As the vapor deposition method, the PVD method or the CVD method described above can be used.

Furthermore, a metal foil such as an aluminum foil can be used as the gas barrier layer. Examples of the material of the aluminum foil include aluminum or an aluminum alloy, and an aluminum-iron alloy (soft material) is preferable. The iron content in the aluminum-iron alloy is preferably 0.3% or more and 9.0% or less, and particularly preferably 0.7% or more and 2.0% or less. When this iron content is less than the above lower limit, the effect of preventing the generation of pinholes may be insufficient. On the other hand, when the iron content exceeds the above upper limit, flexibility is hindered and workability may be reduced. Moreover, as a material of the aluminum foil, flexible aluminum subjected to annealing treatment is preferable from the viewpoint of preventing wrinkles and pinholes.

The lower limit of the thickness (average thickness) of the aluminum foil is preferably 6 μm, and particularly preferably 15 μm. Moreover, as an upper limit of the thickness of aluminum foil, 30 micrometers is preferable and 20 micrometers is especially preferable. When the thickness of the aluminum foil is less than the above lower limit, the aluminum foil is liable to break during processing, and the gas barrier property may be lowered due to pinholes or the like. On the contrary, if the thickness of the aluminum foil exceeds the above upper limit, cracks or the like may occur during processing, and the thickness and weight of the solar cell module protective film increase, resulting in a request for thin and light weight. It will be contrary.

In addition, the surface of the aluminum foil may be subjected to surface treatment such as chromate treatment, phosphate treatment, and lubricating resin coating treatment from the viewpoint of preventing dissolution and corrosion, and from the viewpoint of promoting adhesion. A coupling treatment or the like may be performed.

Furthermore, as the gas barrier layer, a film made of cycloolefin polymer (COC) that is particularly excellent in optical isotropy and water vapor blocking property may be used.

In addition, although the said protective film for solar cell modules can be used as a back sheet laminated | stacked on the back surface side of a solar cell module like the said embodiment, as what is called a front sheet laminated | stacked on the surface side of a solar cell module. Can also be used. Moreover, it can also laminate | stack on both the surface side and back surface side of a solar cell module.

As described above, the protective film for a solar cell module of the present invention can be easily and reliably heat-sealed with the solar cell module, and the productivity and quality of the solar cell module can be improved. Therefore, the protective film for solar cell modules of the present invention and the solar cell module using the same are useful as a constituent element of the solar cell and can be suitably used.

DESCRIPTION OF SYMBOLS 1 Protective film for solar cell modules 3 Thermal

fusion resin layer

11, 111 Protective film for solar cell modules 12 Gas barrier layer 13 Hydrolysis

resistant layer

21, 121 Solar cell module 22 Filler layer 23 Solar cell 24 Filler layer 25 Permeability Photoelectric substrate 31 Solar cell module 32 Translucent substrate 33 Filler layer 34 Solar cell 35 Filler layer 36 Thermal fusion layer 37 Base layer 38 Gas barrier layer 39 Hydrolysis resistant layer 40 Back sheet A Surface direction

Claims

It has a heat-sealing resin layer,
A protective film for a solar cell module, in which a synthetic resin as a main component of the heat-sealing resin layer is crosslinked by electron beam irradiation.
The solar cell module protective film according to claim 1, wherein the heat-sealing resin layer contains a crosslinking agent.
The protective film for a solar cell module according to claim 2, wherein the synthetic resin is polypropylene.
4. The protective film for a solar cell module according to claim 1, wherein a pigment is dispersed and contained in the heat sealing resin layer.
The protective film for a solar cell module according to any one of claims 1 to 4, wherein an irradiation dose of the electron beam is 5 kGy or more and 300 kGy or less.
The protective film for a solar cell module according to any one of claims 1 to 5, comprising only the heat-sealing resin layer.
The protective film for a solar cell module according to claim 6, wherein the average thickness of the heat-sealing resin layer is 40 µm or more and 500 µm or less.
The solar cell module protective film according to any one of claims 1 to 5, further comprising a hydrolysis-resistant layer on one surface side of the heat-sealing resin layer.
The solar cell module protective film according to any one of claims 1 to 5, further comprising a gas barrier layer on one surface side of the heat-sealing resin layer.
The protective film for a solar cell module according to any one of claims 1 to 9, which is used as a back sheet of a solar cell module.
A protective film for a solar cell module according to any one of claims 1 to 10,
A filler layer thermally fused to the surface of the protective film for the solar cell module;
Solar cells disposed in the filler layer;
A solar cell module comprising: a translucent substrate disposed on a surface of the filling layer.