JP2006013413A - Filler layer for solar cell module, solar cell module and reclaimable solar cell element, and manufacturing method for reclaimable transparent front substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a filler layer for a solar cell module and a reclaimable solar cell element or a reclaimable transparent front substrate, for making it possible to recover reusable resources such as transparent front substrates, solar cell elements, etc. from constituting members, and recycle or reuse them. <P>SOLUTION: A filler layer for a solar cell module having a peel layer the main constituent of which is thermoplastic resin (a) whose peel strength measured in a 180° peel test in an atmosphere of 25°C is in the range of 1 N/15 mm width to 150 N/15 mm width, (b) whose Vicat softening temperature measured based on JIS Standard K7206 is in the range of 60°C to 128°C, and (c) whose melt mass-flow rate measured based on JIS Standard K7210 is in the range of 0.1 g/10 min to 50 g/10 min, and (d) an output retention rate of photovoltaic power measured before and after the test according to the rules for a solar cell module using the filler layer is in the range of 80% to 100%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transparent front substrate and a filler layer for a solar cell module having a release layer that can be peeled off from a solar cell element, a method for producing a recycled solar cell element and a recycled transparent front substrate, and a method for reusing a solar cell module.

  In recent years, with increasing awareness of environmental issues, solar power generation systems as an inexhaustible and clean energy source have attracted attention, and their production volume is increasing year by year.

  However, drastic cost reduction is indispensable for the solar power generation system to be used more extensively. Specifically, realization of power generation cost comparable to existing power such as thermal power generation, less energy consumed for production of solar cell elements and solar cell modules, and significant cost reduction of components are required.

  In addition, when a large-scale introduction of a solar power generation system is realized, there is a concern that a large amount of waste equivalent to that will be performed. While the need for building a resource-recycling society has been screamed, the photovoltaic power generation system, which is expected to play a role in the future of clean energy sources, will continue the current treatment method as industrial waste, and consume large amounts of resources. I can't do it. Therefore, it is necessary to construct a recycling system that reduces the burden on the environment by reducing the consumption of resources through the efficient use, recycling, and reuse of substances, and the development of a solar cell module that enables the realization of the recycling system. is required.

  A solar cell module is generally configured by sequentially laminating a transparent front substrate, a filler sheet, a solar cell element, a filler sheet, and a back surface protection sheet, and these are fixed by an aluminum outer frame to form a module. A photovoltaic power generation system is formed by arranging a plurality of these modules into a unit.

  Among these constituent members, transparent front substrates such as glass and solar cell elements are reusable resources that are less damaged than the peripheral members even when exposed to sunlight for a long period of time.

However, many solar cell modules currently on the market use EVA (ethylene-vinyl acetate copolymer resin) sheets as filler sheets, and EVA sheets that are thermosetting are from other module components. Since separation is extremely difficult, it is difficult to recover the transparent front substrate and the solar cell element from the used module. In addition, a long-time thermal crosslinking process is indispensable, and the amount of energy during module manufacture is increased. Furthermore, there is a problem in that an acidic gas is generated as an outgas at the time of crosslinking, not only worsening the surrounding environment, but also damaging solar cell elements and electrodes to promote deterioration.
In addition, the prior art document regarding this invention has not been discovered.

  The present invention recovers reusable resources such as a transparent front substrate and a solar cell element among constituent members of a solar cell module, and is used for a solar cell module that can be recycled or reused. PROBLEM TO BE SOLVED: To provide a material layer, and to provide a method for manufacturing a regenerated solar cell element and a regenerated transparent front substrate that are particularly desired to be reused due to their high cost among reusable resources of solar cell modules Main purpose.

  As a result of intensive studies in view of the above circumstances, the present inventors can recycle a solar cell element or the like from a used solar cell module by providing a release layer mainly composed of a thermoplastic resin as a filler layer. The present inventors have found that resources can be easily recovered and completed the present invention.

  That is, in the present invention, a solar cell in which a transparent front substrate, a wiring electrode and an extraction electrode are disposed, a solar cell element in which a filler layer is disposed on at least one surface, and a back surface protection sheet are laminated in this order. A solar cell module filler layer used in a battery module, wherein the filler layer (a) has a peel strength of 1 N / 15 mm width from a transparent front substrate measured in a 180 ° peel test in an atmosphere at 25 ° C. (B) Vicat softening temperature measured in accordance with JIS standard K7206 is in the range of 60 ° C. to 128 ° C. (c) Measured in accordance with JIS standard K7210 Also having a release layer mainly composed of a thermoplastic resin having a melt mass flow rate in the range of 0.1 g / 10 min to 50 g / 10 min. And the output maintenance factor of the photovoltaic power before and after the test measured based on (d) regulation of the solar cell module using the filler layer is in the range of 80% to 100%. A filler layer for a solar cell module is provided.

  In the present invention, since the solar cell module filler layer has a release layer mainly composed of a thermoplastic resin, reusable resources can be easily recovered from the used solar cell module. Has the advantage. Moreover, in this invention, the solar cell module using the said filler layer for solar cell modules can fully satisfy | fill the required characteristic as a solar cell module by having the above characteristics.

  In the said invention, it is preferable that the said filler layer distribute | arranged between the said transparent front substrate and the said solar cell element is in the range whose (e) total light transmittance is 70%-100%. The filler layer disposed between the transparent front substrate and the solar cell element is preferably within the above range from the viewpoint of power generation efficiency.

Moreover, it is preferable that the said peeling layer is arrange | positioned so that both surfaces of a solar cell element and a transparent front substrate may be touched. Since the release layer is in contact with both sides of the solar cell element and the transparent front substrate, the solar cell element and the transparent front substrate can be easily separated from the used solar cell module, and also attached to the solar cell element and the transparent front substrate. This is because the filler layer thus formed can be easily removed.
At this time, the filler layer may be formed by laminating the release layer, a filler layer made of a resin composition different from the release layer, and the release layer in this order. This is because when the solar cell element and the transparent front substrate are taken out from the solar cell module, the part of the filler layer in contact with them may be a release layer.

  On the other hand, in the present invention, the filler layer may be formed of only the release layer. By forming the filler layer only with the release layer, not only can each constituent member be easily separated from the used solar cell module, but also the filler layer attached to each constituent member can be easily removed. This is because reusable resources such as solar cell elements and transparent front substrates can be recovered by a simpler method.

  In the above invention, the solar cell module is allowed to stand for 1000 hours in a high-temperature and high-humidity state at a temperature of 85 ° C. and a humidity of 85%, and then the filler layer and the transparent front substrate measured in a 180 ° peel test in a 25 ° C. atmosphere The peel strength is preferably in the range of 0.5 N / 15 mm width to 140 N / 15 mm width. This is because if the peel strength from the transparent front substrate is within this range, it can sufficiently withstand long-term use.

Such a thermoplastic resin is preferably a copolymer of polyethylene for polymerization and an ethylenically unsaturated silane compound.
The thermoplastic resin preferably further contains polyethylene for addition. This is because the production of the solar cell module can be suppressed at a low cost.

  In the said invention, it is preferable that Si (silicon) is contained in the said peeling layer as 8 ppm-3500 ppm as superposition | polymerization Si amount. This is because by having the polymerized Si amount within this range, the adhesiveness to the solar cell element, the transparent front substrate, and the back surface protective sheet can be improved.

  The gel fraction of the release layer is preferably 30% or less. When the gel fraction exceeds the above range, the workability at the time of manufacturing the solar cell module is lowered, and the improvement in adhesion with the transparent front substrate and the back surface protective sheet is not recognized. Furthermore, it is because it will become difficult to reproduce | regenerate the members contained in a solar cell module, for example, a solar cell element, and a transparent front substrate, when a gel fraction exceeds the said range.

The release layer used in the present invention preferably further contains at least one additive selected from the group consisting of a light stabilizer, an ultraviolet absorber, a heat stabilizer and an antioxidant. This is because by containing these additives, stable mechanical strength over a long period of time, prevention of yellowing, prevention of cracking, and excellent processing suitability can be obtained.
The present invention also provides a solar cell module using the above-described filler layer for a solar cell module.

The present invention also provides a method for producing a regenerative solar cell element that obtains a regenerative solar cell element from the solar cell module, wherein the solar cell module is heated to a temperature equal to or higher than the softening point of a thermoplastic resin that is a constituent material of the release layer. A regeneration process comprising: a heating process for heating; a separation process for separating a solar cell element by separating a release layer plasticized by heating; and a removing process for removing a filler layer attached to the solar cell element A method for manufacturing a solar cell element is provided.
According to the said method, since a solar cell element can be easily isolate | separated from a used solar cell module, it has the advantage that a reproduction | regeneration solar cell element can be manufactured easily.

  The removal step is preferably performed by physical cleaning that physically removes the filler layer, chemical cleaning that chemically removes the filler layer, or a combination thereof.

Furthermore, in the present invention, there is provided a method for producing a regenerated transparent front substrate obtained from the solar cell module, wherein the solar cell module is heated to a temperature equal to or higher than a softening point of a thermoplastic resin constituting the release layer. A regenerative transparency comprising: a heating step for separating; a separation step for peeling the release layer plasticized by heating to separate the transparent front substrate; and a removal step for removing the filler layer adhering to the transparent front substrate. A method for manufacturing a front substrate is provided.
According to the above method, since the transparent front substrate can be easily separated from the used solar cell module, there is an advantage that the recycled transparent front substrate can be easily manufactured.

  The removal step is preferably performed by physical cleaning that physically removes the filler layer, chemical cleaning that chemically removes the filler layer, or a combination thereof.

  The present invention is also a method for reusing a solar cell module in which members are reused from the above-described solar cell module, wherein the solar cell module is heated to a temperature equal to or higher than a softening point of a thermoplastic resin that is a constituent material of the release layer. There is provided a method for reusing a solar cell module, comprising a heating step and a separation step of separating a transparent front substrate by peeling a release layer plasticized by heating. This is because the solar cell element or the transparent front substrate can be easily reused (recycled or reused) according to this method.

  In the method for reusing a solar cell module, the separation step preferably includes a back surface protection sheet separation step for separating the back surface protection sheet from the solar cell module. For example, in the case of using a material that generates harmful gas by heating, such as a fluororesin, as the back surface protection sheet, the solar cell module can be reused by including a back surface protection sheet separating step for separating the back surface protection sheet from the solar cell module. This is because the environmental load during use can be reduced.

  The solar cell module filler layer according to the present invention heats the solar cell module in which the filler layer is used to a temperature equal to or higher than the softening point of the thermoplastic resin that is the main component of the release layer. Since it can isolate | separate easily, it has the advantage that reusable resources, such as a solar cell element and a transparent front substrate, can be easily collect | recovered from a used solar cell module. The recovered resource can be reused as a constituent member of the solar cell module as it is, or can be recycled by being heated and melted and used as another material. In particular, it is useful in that a regenerated solar cell element and a regenerated transparent front substrate can be easily obtained from a used solar cell module.

  The present invention includes a filler layer for a solar cell module, a solar cell module using the same, a method for manufacturing a regenerated solar cell element and a regenerated transparent front substrate, and a method for reusing the solar cell module. Hereinafter, each will be described in detail.

A. Filler layer for solar cell module The solar cell module filler layer of the present invention is a solar cell element in which a transparent front substrate, a wiring electrode and an extraction electrode are disposed, and a filler layer is disposed on at least one surface; A solar cell module filler layer used in a solar cell module in which a back surface protective sheet is laminated in this order, and the filler layer was measured in (a) a 180 ° peel test in an atmosphere at 25 ° C. The peel strength with the transparent front substrate is in the range of 1 N / 15 mm width to 150 N / 15 mm width, and (b) the Vicat softening temperature measured based on JIS standard K7206 is in the range of 60 ° C. to 128 ° C., (C) Heat having a melt mass flow rate measured in accordance with JIS standard K7210 within a range of 0.1 g / 10 min to 50 g / 10 min. It has a release layer mainly composed of a plastic resin, and the output retention rate of the photovoltaic power before and after the test measured based on (d) regulation of the solar cell module using the filler layer is 80. It is characterized by being in the range of 100% to 100%.

  The configuration of a solar cell module in which such a filler layer for a solar cell module of the present invention is used will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of such a solar cell module. A plurality of solar cell elements 1 are arranged in the same plane, and a wiring electrode 2 and an extraction electrode 3 are arranged between the solar cell elements. Both sides of the solar cell element 1 are sandwiched between an upper filler layer 4a and a lower filler layer 4b. A transparent front substrate 5 is laminated outside the upper filler layer 4a, and the lower filler layer 4b A back surface protection sheet 6 is laminated on the outside. This solar cell module 10 may be fixed by an outer frame 7 such as aluminum. Hereinafter, the filler layer for solar cell modules used for such a solar cell module will be described.

The filler layer of the present invention is an adhesive protective sheet for directly fixing a solar cell element and its peripheral wiring, and has a role of adhering to a transparent front substrate and a back protective sheet.
In the present invention, the filler layer may be disposed on at least one surface of the solar cell element as described above, but is disposed on both surfaces of the solar cell element and sandwiches the solar cell element. It is preferable that it is comprised as follows.
The filler layer used in the solar cell module of the present invention must satisfy the following condition (a) in order to satisfy the required characteristics of the solar cell module.

(A) Adhesiveness to transparent front substrate Since the filler layer for a solar cell module of the present invention has a role of adhering the solar cell element and the transparent front substrate, the filler layer and the transparent front substrate are high. Adhesion is required.

  In the present invention, the peel strength between the filler layer and the transparent front substrate measured in a 180 ° peel test under a 25 ° C. atmosphere is in the range of 1 N / 15 mm width to 150 N / 15 mm width, preferably 3 N / 15 mm. The width is in the range of 150 N / 15 mm width, more preferably in the range of 10 N / 15 mm width to 150 N / 15 mm width.

The peel strength is a value obtained by the following test method.
Testing machine: Tensile testing machine (model name: Tensilon) manufactured by A & D Co., Ltd.
Measurement angle: 180 ° Peeling peeling speed: 50 mm / min

  Within this range, the adhesiveness between the transparent front substrate and the filler layer becomes sufficient, and the generation of voids at these adhesion interfaces can be suppressed.

  In addition, the filler layer used in the present invention preferably retains the above characteristics for a long time, and after the solar cell module is left for 1000 hours in a high temperature and high humidity state of 85 ° C. and 85% humidity. The peel strength between the filler layer and the transparent front substrate measured in a 180 ° peel test in an atmosphere at 25 ° C. is preferably in the range of 0.5 N / 15 mm width to 140 N / 15 mm width, more preferably 3 N. / 15 mm width to 140 N / 15 mm width, more preferably in the range of 10 N / 15 mm width to 140 N / 15 mm width. The measuring method is the same method as described above.

  Moreover, when the filler layer for solar cell modules of this invention is arrange | positioned between a transparent front substrate and a solar cell element, it is preferable to have the characteristic of (e) demonstrated below.

(E) Light transmittance As a filler layer used between a transparent front substrate and a solar cell element, high light transmittance is required. In the present invention, the total light transmittance of the filler layer is in the range of 70% to 100%, preferably 80% to 100%, more preferably 90% to 100%.
The total light transmittance can be measured by a usual method, for example, can be measured by a color computer.

  In addition, as a filler layer used between a back surface protection sheet and a solar cell element, it is not particularly necessary to have the light transmittance as described above, but rather for improving design efficiency and power generation efficiency by reflected light, etc. The filler layer is preferably filled with an inorganic pigment and colored.

  The filler layer used in the present invention satisfies the required characteristics as described above and has a release layer mainly composed of a thermoplastic resin.

  In the solar cell module of the present invention, the filler layer is preferably composed only of a release layer, but even if the release layer has a multi-layer structure of a filler layer made of a resin composition different from the release layer. Good.

  When the filler layer is composed only of the release layer, not only can each component be easily separated from the used solar cell module, but also the filler layer attached to each component can be easily removed. It is advantageous in that reusable resources such as a transparent front substrate and a solar cell element can be recovered by a simpler method.

  On the other hand, in the case of a multilayer structure, it is not particularly limited as long as it is composed of a release layer and a filling layer. For example, a two-layer structure composed of a release layer and a filling layer, a release layer, Examples thereof include a three-layer structure in which a filling layer and a release layer are laminated in this order. By using the filler layer in this manner, it is possible to reduce the amount of the release layer material that is relatively expensive, which is advantageous in terms of cost.

  When the filler layer has a multilayer structure, in the solar cell module of the present invention, it is preferable that the release layer is disposed so as to be in contact with both surfaces of the solar cell element and the transparent front substrate. When the release layer is disposed so as to contact the solar cell element and the transparent front substrate, not only the solar cell element and the transparent front substrate can be easily separated by heating, but also the solar cell element and the transparent front substrate can be easily separated. This is because the release layer attached to the substrate can be easily removed. The solar cell element and the transparent front substrate thus collected can be used as a regenerated solar cell element and a regenerated transparent front substrate.

  Therefore, when the filler layer has a multilayer structure, a three-layer structure in which the release layer, the filler layer, and the release layer described above are laminated in this order is particularly preferable.

  Even when the filler layer is disposed in contact with the solar cell element, the filler layer attached to the solar cell element can be reduced by selecting the material of the filler layer. This is useful in that a regenerated solar cell element can be obtained by washing or the like. In addition, when the filling layer is disposed in contact with the transparent front substrate, the attached filling layer can be removed by chemical cleaning and reused, and the deposit can be suppressed to a small amount. Recycling is possible by heating and melting.

Hereinafter, the peeling layer and the filling layer will be described.
(1) Release layer As described above, the release layer is a layer composed mainly of a thermoplastic resin. Here, “containing as a main component” means that the release layer material contains 50% by weight or more of a thermoplastic resin, preferably 70% by weight or more, more preferably 90% by weight or more. Is.

  In the present invention, since the filler layer has a release layer mainly composed of a thermoplastic resin, the release layer is plasticized by heating to a temperature higher than the softening point of the thermoplastic resin. The releasable layer can be peeled off, so that reusable resources such as solar cell elements can be easily recovered and reused or recycled.

As such a thermoplastic resin, (b) it is necessary that the Vicat softening temperature measured in accordance with JIS standard K7206 is in the range of 60 ° C to 128 ° C, preferably 60 ° C to 115 ° C, Preferably it exists in the range of 60 to 110 degreeC.
When the thermoplastic resin has a softening point within this range, the release layer can be easily plasticized without damaging other components of the solar cell module.

  Further, as the thermoplastic resin used in the present invention, (c) the melt mass flow rate measured based on JIS standard K7210 needs to be within the range of 0.1 g / 10 min to 50 g / 10 min, Is in the range of 0.1 g / 10 min to 10 g / 10 min, more preferably 0.5 g / 10 min to 8 g / 10 min.

  Within this range, the fluidity of the thermoplastic resin at the time of manufacturing the solar cell module becomes appropriate, so that not only is it excellent in workability, but other constituent members such as a transparent front substrate and the release layer When the layers are laminated so as to be in direct contact, the adhesion at the interface is sufficiently ensured.

  Furthermore, the thermoplastic resin used in the present invention is preferably a resin that does not turn yellow even when exposed to sunlight for a long period of time. Specifically, the yellowing degree measured based on JIS standard K7105 is preferably 50% increase or less, more preferably 25% increase or less, and further preferably 5% increase or less.

  The thermoplastic resin and other additives that are the materials for the release layer will be specifically described below.

(Thermoplastic resin)
The thermoplastic resin used in the present invention is not particularly limited as long as it satisfies the above required characteristics. For example, a preferred example is a copolymer of polyethylene for polymerization and an ethylenically unsaturated silane compound. Can be mentioned.

  In the present invention, the copolymer may be any of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer. Among these, a graft copolymer is preferable when adhesion to other components such as a transparent front substrate is required, and in the case of a graft copolymer, the main component of polyethylene for polymerization is used. It is preferably a silane-modified resin in which an ethylenically unsaturated silane compound is arranged as a side chain in the chain.

  The polymerization polyethylene used in the present invention is not particularly limited as long as it is a polyethylene-based polymer. Specifically, the low-density polyethylene, the medium-density polyethylene, the high-density polyethylene, the ultra-low-density polyethylene, and the ultra-low-density polyethylene. High density polyethylene or linear low density polyethylene is preferred. Moreover, these can also use 1 type, or 2 or more types.

Furthermore, as the polyethylene for polymerization, polyethylene having many side chains is preferable. Here, usually, polyethylene with many side chains has a low density, and polyethylene with few side chains has a high density. Therefore, it can be said that polyethylene with a low density is preferable. The density of the polyethylene for polymerization in the present invention is preferably in the range of 0.850 to 0.960 g / cm ³ , more preferably in the range of 0.865 to 0.930 g / cm ³ . This is because if the polymerization polyethylene is a polyethylene having many side chains, that is, a polyethylene having a low density, the ethylenically unsaturated silane compound is easily graft-polymerized to the polymerization polyethylene.

  On the other hand, the ethylenically unsaturated silane compound used in the present invention is not particularly limited, but vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tripropoxy silane, vinyl tributoxy silane, vinyl triopentoxy silane. At least one selected from the group consisting of vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltrimethylenedioxysilane, vinyltriethylenedioxysilane, vinylpropionyloxysilane, vinyltriacetoxysilane, and vinyltricarboxysilane It is preferable that.

  The method for producing the copolymer is not particularly limited, and can be synthesized by an ordinary method. For example, it can be obtained by mixing the polyethylene for polymerization, the ethylenically unsaturated silane compound, and a catalyst and polymerizing them at a high temperature. At this time, the heating temperature is preferably 300 ° C. or lower, more preferably 270 ° C. or lower. If it is higher than this, the silanol group portion is easily crosslinked and gelled.

  In particular, when a graft copolymer is obtained, it can be obtained by heat-melt mixing polyethylene for polymerization, an ethylenically unsaturated silane compound, and a free radical generator. The preferred heating temperature is the same as above.

  Examples of free radical generators include hydroperoxides such as diisopropylbenzene hydroperoxide and 2,5-dimethyl-2,5-di (hydroperoxy) hexane; di-t-butyl peroxide, t-butyl Cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 Dialkyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide Tert-butyl-peroxyisobutyrate, t- Tilperoxyacetate, t-butylperoxy-2-ethylhexanoate, t-butylperoxypivalate, t-butylperoxyoctoate, t-butylperoxyisopropylcarbonate, t-butylperoxybenzoate, di Peroxyesters such as -t-butylperoxyphthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexyne-3 And organic peroxides such as ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, or azo compounds such as azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile).

  The amount of the free radical generator used is preferably 0.001% by weight or more in the silane-modified resin.

  In the above copolymer, the amount of the ethylenically unsaturated silane compound used is preferably in the range of 0.001 to 4 parts by weight, more preferably 0.01 parts by weight, relative to 100 parts by weight of the polyethylene for polymerization. Within 3 parts by weight.

  As the thermoplastic resin used in the present invention, it is preferable to contain polyethylene for addition in addition to the above copolymer. This is because the cost of the copolymer is high, and it is more cost-effective to form the release layer by mixing the additive polyethylene than to form the release layer with only the copolymer.

  The additive polyethylene used in the present invention is at least one selected from the group consisting of low density polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, and linear low density polyethylene. preferable.

The content of polyethylene for addition is preferably 0.01 to 9900 parts by weight, and more preferably 90 to 9,900 parts by weight with respect to 100 parts by weight of the copolymer.
When using 2 or more types of the said copolymer, it is preferable that content of the polyethylene for addition becomes the said range with respect to the total amount of 100 weight part.

(Other additives)
The material of the release layer preferably further contains at least one additive selected from the group consisting of a light stabilizer, an ultraviolet absorber, a heat stabilizer and an antioxidant. This is because by including these additives, it is possible to obtain stable mechanical strength over a long period of time, prevention of yellowing, prevention of cracking, and excellent processing suitability.

  The light stabilizer supplements the active species that initiate photodegradation in the thermoplastic resin used in the release layer, and prevents photooxidation. Specific examples include light stabilizers such as hindered amine compounds and hindered piperidine compounds.

  UV absorbers absorb harmful UV rays in sunlight and convert them into innocuous heat energy within the molecule, which excites the active species that initiate photodegradation in the thermoplastic resin used in the release layer. Is to prevent. Specifically, benzophenone-based, benzotriazole-based, salicylate-based, acrylonitrile-based, metal complex-based, hindered amine-based, and ultrafine titanium oxide (particle size: 0.01 μm to 0.06 μm) or ultrafine zinc oxide (particle size) : 0.01 [mu] m to 0.04 [mu] m).

  Thermal stabilizers include tris (2,4-di-t-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite, and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite And a lactone heat stabilizer such as a reaction product of 8-hydroxy-5,7-di-t-butyl-furan-2-one and o-xylene. It is preferable to use a phosphorus-based heat stabilizer and a lactone-based heat stabilizer in combination.

  The antioxidant prevents oxidative deterioration of the thermoplastic resin used for the release layer. Specific examples include phenol-based, amine-based, sulfur-based, phosphorus-based, and lactone-based antioxidants.

  These light stabilizers, ultraviolet absorbers, heat stabilizers and antioxidants can be used alone or in combination of two or more.

  The contents of the light stabilizer, ultraviolet absorber, heat stabilizer and antioxidant differ depending on the particle shape, density, etc., but are 0.001% to 5% by weight in the material of the release layer, respectively. It is preferable to be within the range.

(Peeling layer)
In the present invention, Si (silicon) is preferably contained in the release layer in the range of 8 ppm to 3500 ppm, particularly 10 ppm to 3000 ppm, especially 50 ppm to 2000 ppm as the amount of polymerized Si. This is because when the amount of polymerized Si is included within this range, the adhesiveness with the transparent front substrate and the solar cell element can be kept good.
In the present invention, as a method for measuring the amount of polymerized Si, only the filler layer is heated, burned, and ashed to convert polymerized Si to SiO _2. A method of quantifying the amount of polymerized Si by ICP emission analysis (high-frequency plasma emission analyzer: ICPS8100 manufactured by Shimadzu Corporation) is used after dissolution.

  The gel fraction of the release layer used in the solar cell module of the present invention is preferably 30% or less, particularly preferably 10% or less, and particularly preferably 0%. When the gel fraction exceeds the above range, the workability at the time of manufacturing the solar cell module is lowered, and the improvement in adhesion with the transparent front substrate and the back surface protective sheet is not recognized. Furthermore, it is because it will become difficult to reproduce | regenerate the members contained in a solar cell module, for example, a solar cell element, and a transparent front substrate, when a gel fraction exceeds the said range.

The gel fraction of the release layer in the present invention refers to, for example, a transparent front substrate, a filler layer, a solar cell element, a filler layer, and a back surface protective sheet laminated in this order, and then vacuumed together as a unit. It refers to the gel fraction of the release layer when a solar cell module is produced using each layer as an integrally molded body by using a normal molding method such as a lamination method for thermocompression bonding.
As a method for measuring the gel fraction, 1 g of the solar cell module filler layer is weighed and placed in an 80 mesh wire mesh bag. The sample with the wire mesh is put into the Soxhlet extractor, and xylene is refluxed at the boiling point. After continuous extraction for 24 hours, the whole wire mesh and the sample are taken out, weighed after the drying treatment, the weight is compared before and after extraction, the weight% of the remaining insoluble matter is measured, and this is used as the gel fraction.

  The release layer used in the present invention is not particularly limited, but in order to obtain the gel fraction, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctate, dioctyltin dilaurate are contained in the release layer. The silanol condensation catalyst for promoting the dehydration condensation reaction between silanols of silicone such as may be added within a range of 0.05 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin, but may not be added. preferable.

(2) Filling layer Next, the filling layer will be described. As described above, the filling layer is not particularly limited as long as it is a resin composition different from that of the release layer and desirably is a resin composition cheaper than the release layer. For example, it is possible to use a resin whose plasticity does not change even when heated to a temperature at which the release layer is plasticized, for example, a cross-linked resin such as EVA to which a cross-linking agent is added.

  The thermosetting resin is not particularly limited as long as it has good workability and is excellent in adhesiveness with other components such as a transparent front substrate and a back surface protective sheet. A known thermosetting resin used as a layer can be used. Further, the filler layer may contain various additives for the purpose of mechanical strength, yellowing prevention and crack prevention.

  Further, when the release layer contains a copolymer of polyethylene for polymerization and an ethylenically unsaturated silane compound as described above and polyethylene for addition, the filling layer may be made of polyethylene. Is possible. This is because the adhesiveness to the release layer is good and the cost can be improved.

(3) Filler layer The thickness of the filler layer for a solar cell module of the present invention is preferably in the range of 10 to 2000 μm, particularly preferably in the range of 100 to 1250 μm. If it is thinner than the above range, the cell cannot be supported, and the cell is likely to be damaged.If it is thicker than the above range, the module weight becomes heavy and not only the workability during installation is bad, but also in terms of cost. It may be disadvantageous.

  The method for producing the filler layer is not particularly limited. For example, when the filler layer is composed of only a release layer, the copolymer is heated and melted as a thermoplastic resin and extruded. Can do. Further, in addition to the above copolymer, polyolefin and additives used as necessary may be mixed and introduced into the hopper of the extruder and heated and melted in the cylinder.

The heating temperature at the time of melting by heating is preferably 300 ° C. or lower, more preferably 270 ° C. or lower. This is because, as described above, the above copolymer is easily gelled by heating to crosslink the silanol group portion.
After heating and melting, it can be formed into a sheet having a predetermined thickness by an existing method such as T-die or inflation, and used as a filler layer used in the solar cell module of the present invention.

  On the other hand, when the filler layer has a multi-layer structure, for example, a lamination method in which the release layer and the filler layer are formed into a sheet shape in advance as described above, and these are integrated by vacuum suction or the like to be thermocompression bonded. Thus, it can be manufactured as an integrally molded body.

(4) Solar cell module The solar cell module using the solar cell module filler layer according to the present invention as described above is required to have a high conversion efficiency maintenance rate in order to withstand long-term use.
Therefore, in the present invention, (d) the output retention rate of the photovoltaic power before and after the test measured based on the regulation of the solar cell module is in the range of 80% to 100%, preferably 90% to 100%. More preferably, it is in the range of 95% to 100%. This is because the conversion efficiency maintenance ratio is sufficiently secured when the photovoltaic output maintenance ratio is within this range.

    In addition, the output maintenance factor of the photovoltaic power before and after the test measured based on the regulation of the solar cell module is measured according to JIS standard C8917 when the solar cell element is a crystal system, and the solar cell element is amorphous. The case is measured according to JIS standard C8938, and the other solar cell elements are measured by a method according to this.

B. Next, the solar cell module of the present invention will be described. The solar cell module of the present invention is characterized by using the solar cell module filler layer described in the above “A. Solar cell module filler layer”.
Hereinafter, each member which comprises the solar cell module of this invention is demonstrated. The filler layer is the same as that described in the above-mentioned “A. Filler layer for solar cell module” as described above, and thus the description thereof is omitted here.

(1) Solar cell element The solar cell element used in the present invention is not particularly limited as long as it has a function as a photovoltaic power, and a known one generally used as a solar cell element is used. Can do. For example, a crystalline silicon solar cell element such as a single crystal silicon type solar cell element or a polycrystalline silicon type solar cell element, an amorphous silicon solar cell element made of a single bond type or a tandem structure type, gallium arsenide (GaAs) or indium phosphorus ( III-V compound semiconductor solar cell elements such as InP) and II-VI compound semiconductor solar cell elements such as cadmium tellurium (CdTe) and copper indium selenide (CuInSe ₂ ).

  A thin film polycrystalline silicon solar cell element, a thin film microcrystalline silicon solar cell element, a hybrid element of a thin film crystalline silicon solar cell element and an amorphous silicon solar cell element, or the like can also be used.

  These solar cell elements are formed on, for example, a glass substrate, a plastic substrate, a metal substrate or the like, a crystalline silicon such as a pn junction structure, an amorphous silicon such as a pin junction structure, or an electromotive force portion such as a compound semiconductor. Is formed and configured.

  In the solar cell module of the present invention, a plurality of solar cell elements 1 are arranged as shown in FIG. When the solar cell element 1 is illuminated with sunlight, electrons (−) and holes (+) are generated, and a current flows out by the wiring electrode 2 and the extraction electrode 3 arranged between the solar cell elements.

(2) Transparent front substrate In the present invention, the transparent front substrate has a function of protecting the inside of the module from wind and rain, external impact, fire, and the like, and ensuring long-term reliability of the solar cell module in outdoor exposure.

  Such a transparent front substrate is not particularly limited as long as it has sunlight permeability, electrical insulation, and is excellent in mechanical or chemical or physical strength. The well-known thing used as a transparent front substrate for solar cell modules can be used. Examples thereof include a glass plate, a fluorine resin sheet, a cyclic polyolefin resin sheet, a polycarbonate resin sheet, a poly (meth) acrylic resin sheet, a polyamide resin sheet, and a polyester resin sheet. Among these, it is preferable to use a glass plate as the transparent front substrate in the present invention. The glass plate is excellent in heat resistance, and can be set to a sufficiently high heating temperature when separating each constituent member from the used solar cell module and removing the filler layer adhering to the glass plate surface. Therefore, reuse or recycling is easy.

(3) Back surface protection sheet The back surface protection sheet is a weather-resistant film that protects the back surface of the solar cell module from the outside world. As a back surface protection sheet used for the solar cell module of the present invention, a metal plate or metal foil such as aluminum, a fluorine resin sheet, a cyclic polyolefin resin sheet, a polycarbonate resin sheet, a poly (meth) acrylic resin sheet, a polyamide And a composite sheet obtained by laminating and laminating a weather-resistant film and a barrier film.
The thickness of the back surface protective sheet used in the present invention is preferably in the range of 20 μm to 500 μm, more preferably in the range of 60 μm to 150 μm.

(4) Other components In the present invention, in addition to the above, other layers may be arbitrarily added and laminated for the purpose of absorbing sunlight, reinforcing, and other purposes.

  In addition, after laminating the constituent members, an outer frame can be provided in order to fix the layers as an integrally molded body. As the outer frame, the same materials as those used for the back surface protection sheet can be used.

(5) Manufacturing method of solar cell module The manufacturing method of the solar cell module of such this invention is not specifically limited, The well-known method conventionally used as a manufacturing method of a solar cell module can be used. For example, a transparent front substrate, a filler layer, a solar cell element, a filler layer, and a back surface protective sheet are stacked in this order, and if necessary, other components are stacked and then vacuum suction is performed. For example, a conventional molding method such as a lamination method in which the layers are integrated and thermocompression-bonded is used, and these layers are thermocompression-molded as an integrally molded body.
In the present invention, the lamination temperature when such a lamination method is used is preferably in the range of 90 ° C to 230 ° C, and more preferably in the range of 110 ° C to 190 ° C. If the temperature is lower than the above range, it may not melt sufficiently and the adhesion to the transparent front substrate, auxiliary electrode, solar cell element, back surface protective sheet, etc. may be deteriorated. This is not preferable because water cross-linking due to is likely to proceed and the gel fraction may increase. The laminating time is preferably within a range of 5 to 60 minutes, and particularly preferably within a range of 8 to 40 minutes. If the time is shorter than the above range, it may not be sufficiently melted and the adhesion with the same member may be deteriorated, and if it is long, there may be a problem in the process, especially depending on the temperature and humidity conditions, the gel fraction This is because it becomes an increase factor. As for humidity, if it is too high, it will lead to an increase in the gel fraction, and if it is too low, there is a possibility that the adhesion to various members will be reduced. .

  Also, two or more layers can be integrated in advance by a lamination method or the like. For example, an integrated transparent front substrate and filler layer or an integrated filler layer and back surface protective sheet can be used.

  In addition, in order to enhance the adhesion between each layer, a heat-melt adhesive, a photo-curing adhesive, etc., whose main component is a (meth) acrylic resin, olefin resin, vinyl resin, etc., as necessary It is also possible to use an adhesive.

  Furthermore, pretreatment such as corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, or the like can be applied to each stacked facing surface.

Further, a surface pretreatment can be performed by previously forming a primer coating agent layer, an undercoat agent layer, an adhesive layer, an anchor coating agent layer, or the like on each of the opposing surfaces of the layers.
The outer frame for fixing the integrally molded body in which these layers are laminated can be attached after the layers are laminated and before thermocompression bonding, but may be attached after the thermocompression bonding.

C. Next, a method for manufacturing a regenerative solar cell element according to the present invention will be described.
A method for producing a regenerative solar cell element according to the present invention is a method for producing a regenerative solar cell element that obtains a regenerative solar cell element from the solar cell module described above. A heating step of heating to a temperature equal to or higher than the softening point, a separation step of peeling the release layer plasticized by heating to separate the solar cell element, and a removal step of removing the filler layer attached to the solar cell element It is characterized by that. Hereinafter, each step will be described.

1. Heating Step In the heating step, the solar cell module is heated to a temperature equal to or higher than the softening point of the thermoplastic resin that is the constituent material of the release layer. By heating to a temperature equal to or higher than the softening point of the thermoplastic resin in this manner, the plasticity of the thermoplastic resin, which is a constituent material of the release layer, changes, and the release layer can be easily peeled off.

  The heating method includes a method of putting a solar cell module in a container filled with a heated gas, a solid such as a liquid or a powder, or a combination thereof, or a method of holding a solar cell module on a heated hot plate. Can be mentioned.

  The heating temperature is a temperature equal to or higher than the softening point of the thermoplastic resin that is a constituent material of the release layer, and is appropriately selected according to the thermoplastic resin used. Here, the softening point refers to the Vicat softening temperature measured based on the JIS standard K7206 of the thermoplastic resin. The heating temperature in the heating step is preferably the same temperature as the Vicat softening temperature, or preferably 0 ° C to 390 ° C or higher and higher than the Vicat temperature, more preferably 10 ° C to 290 ° C or more, and further preferably 20 ° C to 20 ° C or more. It is preferably within a range of 140 ° C. or higher.

  The specific heating temperature in the heating step is preferably in the range of 60 ° C to 450 ° C, more preferably in the range of 70 ° C to 350 ° C, and still more preferably in the range of 80 ° C to 200 ° C.

2. Separation Step In the separation step of the present invention, the solar cell element is separated by peeling the release layer plasticized by heating in the heating step. The separation method may be performed by any method as long as it can be separated without damaging the solar cell element.
Examples of the separation method include a method using a separation means and a method of applying a shear stress.

  The method using the separation means is a filler layer disposed between the transparent front substrate and the solar cell element of the solar cell module heated in the heating step described above, and disposed between the solar cell element and the back surface protective sheet. The filler layer is cut by passing the separating means, and the transparent front substrate and the back surface protective sheet are separated from the solar cell element. As such a separating means, a softened filler layer is used. Although it will not specifically limit if it is a means which can cut | disconnect, A wire etc. can be mentioned as a suitable example. The separation means using such a wire will be described with reference to the drawings. For example, as shown in FIG. 2, a wire 24 using a separation device including a wire fixing jig 21, a module pressing jig 22, and an oil bath 23. The means which peels the solar cell element 1 and the filler layer 4 by moving can be mentioned. FIG. 3 is a perspective view of the separation device.

  Moreover, as a method of applying the shearing force, the solar cell module heated in the heating step described above is extruded in the lateral direction with respect to at least one of the solar cell element or the transparent front substrate and at least one of the solar cell element or the back surface protective sheet. Thus, a shearing force is applied to the filler layer, thereby separating the transparent front substrate and the back surface protective sheet from the solar cell element.

3. Removal Step In the removal step in the present invention, the filler layer attached to the solar cell element is removed. Examples of the removal method include physical cleaning that physically removes the filler layer, chemical cleaning that chemically removes the filler layer, or a combination thereof. Further, when a plurality of chemical cleaning methods are combined, a plurality of physical cleaning methods are combined, and further, these may be combined.

  Examples of the physical cleaning include a method of spraying gas, liquid or solid, or a combination thereof, and a method of wiping with a cloth or the like. The physical cleaning is preferably performed while the filler layer is heated. For example, an air blast method or a shot blast method in which a shot of a steel ball is jetted at high speed using compressed air or centrifugal force in a heated atmosphere can be used. If the deposit is a part corresponding to the release layer, physical cleaning is useful.

  In this physical cleaning, it is necessary to remove deposits so as not to damage the regenerative solar cell element. Therefore, for example, when the fine particle is sprayed to remove the filler layer, the particle size of the fine particle is preferably in the range of 5 μm to 500 μm. For example, solids that can be used for physical cleaning include steel abrasives, stainless steel abrasives, zinc abrasives, copper abrasives, alumina abrasives, silicon carbide abrasives, glass abrasives, resin abrasives, Examples thereof include silica sand, ceramic beads, zirconia, slag, calcium carbonate, and baking soda.

Examples of the liquid include a heated organic solvent and a metal liquid.
Examples of the gas include air, nitrogen gas, argon gas, and inert gas such as helium gas.

Examples of chemical cleaning include a method of treating with an acid or an alkali, a method of dissolving with a solvent, and the like. The solvent that can be used for chemical cleaning can be appropriately selected depending on the adhering filler layer.
Specific examples include a method of immersing a separated solar cell element in an organic solvent such as xylene and removing the release layer from the surface of the solar cell element. An organic solvent such as xylene may be heated or refluxed.
Moreover, the method etc. which apply | coat stearic acid to the isolate | separated solar cell element in a heating state, and remove a peeling layer are mentioned.

In addition, stearic acid is applied to the separated solar cell element in a heated state to remove the filler layer to some extent, and then the solar cell element with the filler layer remaining on the surface is immersed in an organic solvent such as xylene to obtain a surface of the solar cell element. And a method of peeling off the remaining filler layer. An organic solvent such as xylene may be heated or refluxed.
Further, after the solar cell element separated in an organic solvent such as xylene is immersed and the filler layer is removed to some extent from the surface of the solar cell element, the solar cell element with the filler layer remaining on the surface is taken out and stearinized in a heated state. Examples include a method of applying an acid and peeling off the filler layer remaining on the surface of the solar cell element. An organic solvent such as xylene may be heated or refluxed.

  As a method of combining physical cleaning and chemical cleaning, for example, a method in which the deposit is completely removed by an air blast method or a shot blast method after being immersed in a liquid that dissolves the deposit to some extent.

  As described above, deposits can be removed, and a regenerated solar cell element can be easily manufactured from a used solar cell module by washing with alcohol or the like as necessary.

  In addition, the manufacturing method of the said reproduction | regeneration solar cell element is applicable when collect | recovering other structural members, such as a transparent front substrate, from a solar cell module. For example, when recovering the surface glass used as the transparent front substrate, it can be reused as the surface glass for the solar cell module if the deposits can be completely removed. In addition, when the deposits cannot be completely removed or the surface glass is broken, it can be recycled as another material by melting and heating. In that case, since the amount of adhesion to the surface glass is small compared to the conventional case, the recycling cost can be reduced.

C. Method for Producing Recycled Transparent Front Substrate The method for producing a regenerated transparent front substrate of the present invention is a method for producing a regenerated transparent front substrate that obtains a regenerated transparent front substrate from the above-described solar cell module, and the solar cell module is formed of a release layer A heating process for heating to a temperature equal to or higher than the softening point of the thermoplastic resin, a separation process for separating the recycled transparent front substrate by peeling the release layer plasticized by heating, and a filler layer attached to the transparent front substrate And a removing step for removing the. Hereinafter, each step will be described.

1. Heating Step In the heating step, the peeling layer can be easily peeled by heating the solar cell module to a temperature equal to or higher than the softening point of the thermoplastic resin that is the constituent material of the peeling layer. The heating method and the heating temperature are the same as those described in the column “B. Manufacturing method of regenerative solar cell element”, so description thereof is omitted here.

2. Separation Step In the separation step, the transparent front substrate is separated by peeling the release layer plasticized by heating in the heating step. The separation method is not particularly limited as long as it does not damage the transparent front substrate.
Specifically, a method using the separation means described in the above-mentioned section “B. Manufacturing method of regenerated solar cell element” and a method of applying shear stress can be mentioned.

3. Removal Step In the removal step, the filler layer attached to the transparent front substrate is removed. The removal method can be performed by physical cleaning, chemical cleaning, or a combination thereof, as described in the section of “B. Manufacturing method of regenerated solar cell element”. Since details are as described above, description thereof is omitted here.
After removing the filler layer, the recycled transparent front substrate can be easily produced from the used solar cell module by washing with alcohol or the like if necessary.

D. Method for Reusing Solar Cell Modules Finally, a method for reusing solar cell modules according to the present invention will be described. A method for reusing a solar cell module according to the present invention is a method for reusing a solar cell module in which a member is reused from the solar cell module described in the section “A. Solar cell module”. It comprises a heating step of heating to a temperature equal to or higher than the softening point of the thermoplastic resin, which is a constituent material, and a separation step of peeling and separating the member from the release layer plasticized by heating.

According to the method for reusing a solar cell module of the present invention, for example, a member such as a solar cell element included in a solar cell module which is regarded as a defective product during processing of the solar cell module, a solar cell element of a solar cell module collected after use, or the like These members can be reused (recycled or reused), which is not only advantageous in terms of cost but also suitable when considering the global environment.
As described above, the solar cell module used in the method for reusing a solar cell module of the present invention is a solar cell module that is determined to be defective in the manufacturing process of the solar cell module, or a solar cell that is recovered after use. List modules.

  In the present invention, such a solar cell module is subjected to a heating step and a separation step. The heating step and the separation step are performed according to the above-mentioned “B. Manufacturing method of regenerative solar cell element” or “C Since it is the same as that described in “Method for Manufacturing Recycled Transparent Front Substrate”, description thereof is omitted here.

In addition, in this invention, it is preferable that a back surface protection sheet separation process is performed simultaneously in the said separation process.
For example, when using a material that generates harmful gas by heating, such as a fluororesin, as the back surface protection sheet, the back surface protection sheet can be reused by separating the back surface protection sheet from the solar cell module in the back surface protection sheet separation step. This is because sometimes it is possible to prevent generation of harmful gas due to heating of the back surface protection sheet, thereby reducing the environmental load.
The separation of the back surface protection sheet may be performed simultaneously with the separation of the solar cell element or the transparent front substrate, or may be performed before the separation of these members.

In the present invention, the process after the separation step differs depending on whether the member is used as it is (reuse) or the member is used as a material (recycle). In the case of reuse, for example, when the member is a solar cell element or a transparent front substrate, the processing method described in the above-mentioned “B. Method for manufacturing regenerated solar cell element” or “C. Method for manufacturing regenerated transparent front substrate”. Etc. are reused. On the other hand, when it is recycled, it is recycled according to the recycling method described later.
Thus, whether to reuse or recycle is determined at the stage of the solar cell module, for example, it is clear that the solar cell element has already been damaged, and after the separation step, the solar cell It may be determined by looking at the state of members constituting the solar cell module such as an element and a transparent front substrate.

(Recycling Law)
In the method for reusing a solar cell module of the present invention, a method for recycling a solar cell element and a transparent front substrate among members of the solar cell module will be described.
1. In the case where the element is damaged after the separation step, the solar cell element is recycled without being subjected to the above-described removal step or after being used for a different use from the solar cell element.
Specifically, it is used for re-melting to re-form and recycle Si ingots, or for other uses when there are many impurities in Si.

2. Transparent Front Substrate Also in this case, after the separation step, the above-described removal step is performed or is performed, and then used as an application different from the transparent front substrate. Specifically, it is a method of recovering glass raw material (cullet) and melting it to re-form the plate glass.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
(1) Manufacture of Filler Layer Vicat softening temperature (hereinafter also referred to as Vicat softening temperature) measured based on JIS standard K7206 80 ° C., melting point 90 ° C., and melt mass flow rate (hereinafter also referred to as MFR) at 190 ° C. ) 100 parts by weight of linear low-density polyethylene having a density of 2 g / 10 min and a density of 0.898 g / cm ³ , 2.0 parts by weight of vinyltrimethoxysilane, and a free radical generator (t-butyl-peroxyisobutyrate) 0.1 part by weight was mixed and graft copolymerized at a melt stirring temperature of 200 ° C. to prepare a silane-modified linear low-density polyethylene modified with silane.

3.75 parts by weight of a hindered amine light stabilizer, 3.75 parts by weight of a benzotriazole ultraviolet absorber, 0.5 part by weight of a phosphorus heat stabilizer, and 100 parts by weight of a linear low density polyethylene Were mixed and melt processed to obtain a master batch.
MFR 3.5 g / 10 min, density 0.900 g / cm ^{3 at} Vicat softening temperature 70 ° C., melting point 90 ° C., 190 ° C. with respect to 20 parts by weight of the above-mentioned silane-modified linear low-density polyethylene having a silane modification rate of 0.3%. 80 parts by weight of a linear low density polyethylene and 5 parts by weight of the above masterbatch were added and mixed. Using a 150 mmφ extruder and a film molding machine having a 1000-width T die, a resin temperature of 230 ° C., a take-up speed of 4 m / A film having a thickness of 400 μm was formed in min.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 600 ppm.

(2) Manufacture of solar cell module Using the obtained film as a filler layer, a glass plate (transparent front substrate) with a thickness of 3 mm, a filler layer with a thickness of 400 μm, a solar cell element made of polycrystalline silicon, with a thickness of 400 μm As a filler layer and a back surface protection sheet, a laminated sheet composed of a 38 μm-thick polyvinyl fluoride resin sheet (PVF), a 30 μm-thick aluminum foil, and a 38 μm-thick polyvinyl fluoride resin sheet (PVF) is used. The solar cell module of the present invention was manufactured by sequentially laminating and pressing with a vacuum laminator for manufacturing a solar cell module at 150 ° C. for 15 minutes with the solar cell element surface facing up. As a result of cutting out the filler layer from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 2)
A silane-modified linear low-density polyethylene similar to that in Example 1 was prepared, and a master batch similar to that in Example 1 was prepared.
100 parts by weight of the silane-modified linear low density polyethylene and 5 parts by weight of the master batch were added and mixed, and a 400 μm film was formed as in Example 1.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
A solar cell module was manufactured in the same manner as in Example 1. As a result of cutting out the filler layer from the obtained solar cell module and measuring the gel fraction, it was 0%.

Example 3
A silane-modified linear low-density polyethylene similar to that in Example 1 was prepared, and a master batch similar to that in Example 1 was prepared.
1. Release layer (outer layer)
Linear low density polyethylene 80 having an MFR of 3.5 g / 10 min and a density of 0.900 g / cm ³ at Vicat softening temperature of 70 ° C., melting point of 90 ° C. and 190 ° C. with respect to 20 parts by weight of the above silane-modified linear low density polyethylene. Part by weight and 5 parts by weight of the above master batch were added and mixed.
2. Packing layer (inner layer)
A linear low-density polyethylene having an MFR of 3.5 g / 10 min and a density of 0.902 g / cm ^{3 at} a Vicat softening temperature of 75 ° C., a melting point of 100 ° C. and 190 ° C. was used.

The release layer and the filler layer were laminated in the order of the release layer, the filler layer, and the release layer. The film thickness ratio was 1: 6: 1. In the production, a multilayer extruder having a thickness of 400 μm was formed at a resin temperature of 230 ° C. and a take-off speed of 4 m / min using a multilayer extruder having 150 mmφ and 50 mmφ and a film forming machine having a 1000-width T die.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained release layer was 600 ppm.
A solar cell module was manufactured in the same manner as in Example 1. As a result of cutting out the filler layer from the obtained solar cell module and measuring the gel fraction, it was 0%.

Example 4
A silane-modified linear low-density polyethylene similar to that in Example 1 was prepared, and a master batch similar to that in Example 1 was prepared.
1. Release layer (outer layer)
100 parts by weight of the above silane-modified linear low density polyethylene and 5 parts by weight of the above master batch were added and mixed.
2. Packing layer (inner layer)
The same as in Example 3.

A multilayer film was formed in the same manner as in Example 3.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained release layer was 3000 ppm.
A solar cell module was manufactured in the same manner as in Example 1. As a result of cutting out the filler layer from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 5)
A silane-modified linear low-density polyethylene similar to that in Example 1 was prepared, and a master batch similar to that in Example 1 was prepared.
1. Release layer (outer layer)
Same as Example 3.
2. Packing layer (inner layer)
100 parts by weight of linear low-density polyethylene having a Vicat softening temperature of 75 ° C., a melting point of 100 ° C., and a MFR of 3.5 g / 10 min and a density of 0.902 g / cm ³ at 190 ° C. and 5 parts by weight of the master batch were added and mixed.

A multilayer film was formed in the same manner as in Example 3.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained release layer was 600 ppm.
A solar cell module was manufactured in the same manner as in Example 1. As a result of cutting out the filler layer from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 6)
A silane-modified linear low-density polyethylene similar to that in Example 1 was prepared, and a master batch similar to that in Example 1 was prepared.
1. Release layer (outer layer)
Same as Example 3.
2. Packing layer (inner layer)
Linear low density polyethylene 95 having an MFR of 3.5 g / 10 min and a density of 0.902 g / cm ³ at Vicat softening temperature of 75 ° C., melting point of 100 ° C. and 190 ° C. with respect to 5 parts by weight of the above silane-modified linear low density polyethylene. Part by weight and 5 parts by weight of the above master batch were added and mixed.

A multilayer film was formed in the same manner as in Example 3.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained release layer was 600 ppm.
A solar cell module was manufactured in the same manner as in Example 1. As a result of cutting out the filler layer from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 7)
A silane-modified linear low-density polyethylene similar to that in Example 1 was prepared, and a master batch similar to that in Example 1 was prepared.
1. Release layer (outer layer)
A film having a thickness of 50 μm was formed in the same manner as in Example 1.
2. Packing layer (inner layer)
An ethylene-vinyl acetate copolymer sheet having a thickness of 300 μm was used.

  3 mm thick glass plate (transparent front substrate), 50 μm thick release layer, 300 μm thick ethylene-vinyl acetate copolymer sheet, 50 μm thick release layer, solar cell element made of polycrystalline silicon, 50 μm thick release layer As a layer, an ethylene-vinyl acetate copolymer sheet having a thickness of 300 μm, the release layer having a thickness of 50 μm, and a back surface protective sheet, a polyvinyl fluoride resin sheet (PVF) having a thickness of 38 μm, an aluminum foil having a thickness of 30 μm, and a 38 μm thickness Laminate sheets made of polyvinyl fluoride resin sheet (PVF) are laminated in this order, and the solar cell element surface is faced up, and after being pressure-bonded at 150 ° C. for 15 minutes with a vacuum laminator for manufacturing a solar cell module, 150 The solar cell module of the present invention was manufactured by heating in an oven at 15 ° C. for 15 minutes. The release layer was cut out from the obtained solar cell module and the gel fraction was measured. As a result, it was 0%.

(Example 8)
(1) Production of filler layer 100 parts by weight of linear low density polyethylene as in Example 1, 0.005 parts by weight of vinyltrimethoxysilane, free radical generator (t-butyl-peroxyisobutyrate) ) 0.1 parts by weight was mixed and graft copolymerized at a melt stirring temperature of 200 ° C. to prepare a silane-modified linear low-density polyethylene modified with silane.
To 100 parts by weight of the above-mentioned silane-modified linear low-density polyethylene, 5 parts by weight of the same master batch as in Example 1 was added and mixed, and a 150 mmφ extruder, a film forming machine having a 1000-width T die was used, A film having a thickness of 400 μm was formed at a resin temperature of 230 ° C. and a take-up speed of 4 m / min.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 8 ppm.

(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protective sheet as in Example 1 were laminated in the same manner as in Example 1, and solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by using a vacuum laminator for manufacturing a solar cell module at 90 ° C. for 5 minutes. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

Example 9
(1) Production of Filler Layer 5 parts by weight of the same master batch as in Example 1 is added to and mixed with 100 parts by weight of the same silane-modified linear low density polyethylene as in Example 1, 150 mmφ extruder, 1000 width A film forming machine having a T die was used to form a film having a thickness of 400 μm at a resin temperature of 230 ° C. and a take-off speed of 4 m / min.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protection sheet as in Example 1 were laminated in the same manner as in Example 1, and the solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by pressure bonding at 190 ° C. for 90 minutes with a vacuum laminator for manufacturing the solar cell module. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 15%.

(Example 10)
(1) Production of filler layer 100 parts by weight of linear low density polyethylene having a Vicat softening temperature of 60 ° C., a melting point of 70 ° C., an MFR of 15 g / 10 min at 190 ° C. and a density of 0.865 g / cm ³ , and vinyltrimethoxysilane. 0 parts by weight and 0.1 parts by weight of a free radical generator (t-butyl-peroxyisobutyrate) are mixed and graft-copolymerized at a melt stirring temperature of 1700C to obtain a silane-modified linear low Density polyethylene was prepared.
5 parts by weight of the same master batch as in Example 1 was added to and mixed with 100 parts by weight of the above silane-modified linear low density polyethylene, and a film was formed in the same manner as in Example 1.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protective sheet as in Example 1 were laminated in the same manner as in Example 1, and solar cell element The solar cell module of the present invention was manufactured by pressure bonding at 90 ° C. for 15 minutes with a vacuum laminator for manufacturing the solar cell module with the surface facing up. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 11)
(1) Manufacture of filler layer 100 parts by weight of high density polyethylene with MFR 5 g / 10 min and density 0.950 g / cm ³ at Vicat softening temperature 127 ° C., melting point 135 ° C., 190 ° C., and 2.0 parts by weight of vinyltrimethoxysilane And a free radical generator (t-butyl-peroxyisobutyrate) (0.1 part by weight) were mixed and graft copolymerized at a melt stirring temperature of 300 ° C. to prepare a silane-modified linear low-density polyethylene.
5 parts by weight of the same master batch as in Example 1 is added to 100 parts by weight of the above-mentioned silane-modified linear low-density polyethylene, mixed, and a 150 mmφ extruder and a film forming machine having a 1000-width T die are used. A film having a thickness of 400 μm was formed at a resin temperature of 300 ° C. and a take-off speed of 4 m / min.
Film formation could be carried out without any problem. Moreover, the external appearance of the obtained film was favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protection sheet as in Example 1 were laminated in the same manner as in Example 1, and the solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by using a vacuum laminator for manufacturing a solar cell module at 230 ° C. for 15 minutes. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 12)
(1) Production of filler layer 100 parts by weight of linear low-density polyethylene having a MFR of 0.1 g / 10 min and a density of 0.900 g / cm ³ at Vicat softening temperature of 80 ° C., melting point of 90 ° C. and 190 ° C., and vinyltrimethoxysilane Silane-modified linear chain obtained by mixing 2.0 parts by weight and 0.1 part by weight of a free radical generator (t-butyl-peroxyisobutyrate) and graft-copolymerizing the mixture at a melt stirring temperature of 200 ° C. A low density polyethylene was prepared.
To 100 parts by weight of the above-mentioned silane-modified linear low density polyethylene, 5 parts by weight of the same master batch as in Example 1 was added and mixed, and a 150 mmφ extruder, a film forming machine having a 1000-width T die was used, A film having a thickness of 400 μm was formed at a resin temperature of 250 ° C. and a take-up speed of 4 m / min.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protective sheet as in Example 1 were laminated in the same manner as in Example 1, and solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by pressure bonding at 150 ° C. for 60 minutes with a vacuum laminator for manufacturing the solar cell module. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 13)
(1) Production of filler layer 100 parts by weight of linear low density polyethylene having a Vicat softening temperature of 80 ° C., a melting point of 90 ° C., an MFR of 50 g / 10 min at 190 ° C. and a density of 0.880 g / cm ³ , and vinyltrimethoxysilane. 0 part by weight and 0.1 part by weight of a free radical generator (t-butyl-peroxyisobutyrate) are mixed and graft-copolymerized at a melt stirring temperature of 200 ° C. to give a silane-modified linear low Density polyethylene was prepared.
To 100 parts by weight of the above silane-modified linear low density polyethylene, 5 parts by weight of the master batch of Example 1 was added and mixed. Using a 150 mmφ extruder, a film molding machine having a 1000-width T-die, the resin temperature A film having a thickness of 400 μm was formed at 190 ° C. and a take-up speed of 15 m / min.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protection sheet as in Example 1 were laminated in the same manner as in Example 1, and the solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by pressure bonding at 110 ° C. for 30 minutes with a vacuum laminator for manufacturing the solar cell module. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 14)
(1) Production of filler layer 100 parts by weight of linear low density polyethylene having a Vicat softening temperature of 80 ° C., a melting point of 90 ° C., a MFR of 2 g / 10 min at 190 ° C. and a density of 0.898 g / cm ³ , vinyltrimethoxysilane; 0 part by weight and 0.1 part by weight of a free radical generator (t-butyl-peroxyisobutyrate) are mixed and graft-copolymerized at a melt stirring temperature of 200 ° C. to give a silane-modified linear low Density polyethylene was prepared.
For 100 parts by weight of the above-mentioned silane-modified linear low density polyethylene, linear low density polyethylene 0 having a Vicat softening temperature of 70 ° C., a melting point of 90 ° C., an MFR of 3.5 g / 10 min at 190 ° C., and a density of 0.900 g / cm ³ .01 parts by weight and 5 parts by weight of the master batch of Example 1 were added and mixed. Using a 150 mmφ extruder and a film forming machine having a 1000-width T die, the resin temperature was 230 ° C., the take-up speed was 4 m / min, and the thickness was 400 μm. The film was formed.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3500 ppm.
(2) Manufacture of solar cell module The obtained film was used as a filler layer, and the solar cell module of the present invention was manufactured in the same manner as in Example 1. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 15)
(1) Production of Filler Layer A film having a polymerized Si amount of 3500 ppm was produced in the same manner as in Example 14 above.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protective sheet as in Example 1 were laminated in the same manner as in Example 1, and the solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by pressure bonding at 230 ° C. for 60 minutes with a vacuum laminator for manufacturing the solar cell module. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 30%.

(Example 16)
(1) Production of Filler Layer 80 parts by weight of linear low density polyethylene similar to Example 1 and 20 parts by weight of silane-modified linear low density polyethylene similar to Example 1 are the same as in Example 1. 5 parts by weight of the master batch was added and mixed, and a film having a thickness of 10 μm was formed at a resin temperature of 230 ° C. and a take-off speed of 18 m / min using a 150 mmφ extruder and a film forming machine having a 1000-width T die.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 600 ppm.
(2) Manufacture of solar cell module The obtained film was used as a filler layer, and the solar cell module of the present invention was manufactured in the same manner as in Example 1. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 17)
(1) Production of Filler Layer 80 parts by weight of linear low density polyethylene similar to Example 1 and 20 parts by weight of silane-modified linear low density polyethylene similar to Example 1 are the same as in Example 1. 5 parts by weight of the master batch was added and mixed, and a film having a thickness of 2000 μm was formed at a resin temperature of 230 ° C. and a take-up speed of 1 m / min using a 150 mmφ extruder and a film forming machine having a 1000-width T die.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 600 ppm.
(2) Manufacture of solar cell module The obtained film was used as a filler layer, and the solar cell module of the present invention was manufactured in the same manner as in Example 1. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Example 18)
(1) Production of Filler Layer For 100 parts by weight of the same silane-modified linear low density polyethylene as in Example 1, 9900 parts by weight of linear low density polyethylene as in Example 1 and the same as in Example 1 5 parts by weight of the master batch was added and mixed, and a film was formed in the same manner as in Example 1.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 30 ppm.
(2) Manufacture of solar cell module The obtained film was used as a filler layer, and the solar cell module of the present invention was manufactured in the same manner as in Example 1. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Comparative Example 1)
It carried out like Example 1 except not having used silane modification linear low density polyethylene.
(Comparative Example 2)
A glass plate having a thickness of 3 mm is used as a transparent front substrate for a solar cell module, and a 400 μm thick ethylene-vinyl acetate copolymer sheet, a solar cell element made of polycrystalline silicon, and a 400 μm thick ethylene-vinyl acetate on one surface thereof. As a copolymer sheet and a back surface protection sheet, a laminated sheet composed of a 38 μm thick polyvinyl fluoride resin sheet (PVF), a 30 μm thick aluminum foil, and a 38 μm thick polyvinyl fluoride resin sheet (PVF) is laminated. A solar cell module was manufactured by pressing a solar cell element face up with a laminator for manufacturing a solar cell module at 150 ° C. for 15 minutes and then heating in a 150 ° C. oven for 15 minutes.
As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 94%.

(Comparative Example 3)
(1) Production of filler layer 100 parts by weight of linear low density polyethylene as in Example 1, 0.0007 parts by weight of vinyltrimethoxysilane, free radical generator (t-butyl-peroxyisobutyrate) ) 0.1 parts by weight was mixed and graft copolymerized at a melt stirring temperature of 200 ° C. to prepare a silane-modified linear low-density polyethylene modified with silane.
To 100 parts by weight of the above-mentioned silane-modified linear low-density polyethylene, 5 parts by weight of the same master batch as in Example 1 was added and mixed, and a 150 mmφ extruder, a film forming machine having a 1000-width T die was used, A film having a thickness of 400 μm was formed at a resin temperature of 230 ° C. and a take-up speed of 4 m / min.
Film formation could be carried out without any problem. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 1 ppm.
(2) Manufacture of solar cell module Using the obtained film as a filler layer, the same transparent front substrate, solar cell element, and back surface protective sheet as in Example 1 were laminated in the same manner as in Example 1, and solar cell element The solar cell module of the present invention was manufactured with the surface facing upward by using a vacuum laminator for manufacturing the solar cell module at 150 ° C. for 15 minutes. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 0%.

(Comparative Example 4)
(1) Production of Filler Layer A film was produced in the same manner as in Example 12 except that 100 parts by weight of linear low density polyethylene having an MFR of 0.01 g / 10 min at 190 ° C. was used.
Although film formation was extremely difficult, it could be carried out. Moreover, the external appearance and the total light transmittance of the obtained film were favorable. The amount of polymerized Si in the obtained film was 3000 ppm.
(2) Manufacture of solar cell module A solar cell module was manufactured in the same manner as in Example 12 using the film obtained above.

(Comparative Example 5)
(1) Production of Filler Layer A film was produced in the same manner as in Example 13 except that 100 parts by weight of linear low density polyethylene having an MFR of 60 g / 10 min at 190 ° C. was used.
(2) Manufacture of solar cell module Using the film obtained above, a solar cell module was manufactured in the same manner as in Example 13, but the fluidity during modularization was high, the constituent members contacted, and the cell was damaged. Therefore, it could not be modularized.

(Comparative Example 6)
(1) Production of Filler Layer Similar to Example 1, 20 parts by weight of silane-modified linear low density polyethylene similar to Example 1 above, 80 parts by weight of linear low density polyethylene similar to Example 1 5 parts by weight of the master batch and 5 parts by weight of a crosslinking agent were mixed to produce a film having a polymerized Si amount of 3000 ppm.
(2) Manufacture of solar cell module The obtained film was used as a filler layer, and the solar cell module of the present invention was manufactured in the same manner as in Example 1. As a result of cutting out a filler sample from the obtained solar cell module and measuring the gel fraction, it was 32%.

(Characteristic evaluation)
The following tests were conducted on the filler layers used in the solar cell modules obtained in Examples 1 to 18 and Comparative Examples 1 to 4 and 6.

(1) Measurement of total light transmittance About the filler layer used for the solar cell module obtained by the said Examples 1-18 and Comparative Examples 1-4, 6, the total light transmittance (%) by the color computer. ) Was measured. Specifically, the solar cell module filler layer sheet is sandwiched between front and back ethylene tetrafluoroethylene copolymer films (trade name: AFLEX100N, manufactured by Asahi Glass Co., Ltd.) and 150 ° C. at 15 ° C. using a vacuum laminator for manufacturing solar cell modules. After pressure-bonding for a minute, the ethylene tetrafluoroethylene copolymer film was peeled off, and only the heated filler layer sheet for solar cell module was measured.

(2) Measurement of adhesion of transparent front substrate Immediately after the production of the solar cell modules obtained in Examples 1 to 18 and Comparative Examples 1 to 4 and 6, and in a high temperature and high humidity state at a temperature of 85 ° C. and a humidity of 85%. The peel strength (N / 15 mm width) at room temperature (25 ° C.) between the filler layer after being left for 1000 hours and the transparent front substrate was measured.

(3) Measurement of solar cell element adhesion After the solar cell modules obtained in Examples 1 to 18 and Comparative Examples 1 to 4 and 6 were left in a high temperature and high humidity state of 85 ° C. and 85% humidity for 1000 hours. The peel strength (N / 15 mm width) at room temperature (25 ° C.) between the filler layer and the solar cell element made of polycrystalline silicon was measured.

(4) Measurement of photovoltaic power output retention rate Based on JIS standard C8917, the solar cell modules obtained in Examples 1 to 18 and Comparative Examples 1 to 4 and 6 were subjected to environmental tests. The photovoltaic power output before and after the test was measured for comparative evaluation.
The measurement results of the above test are shown in Table 1.

  As is apparent from the measurement results shown in Table 1, the total light transmittance of the filler layers used in the solar cell modules of Examples 1 to 18 was excellent. Moreover, the peeling strength with the transparent front substrate and solar cell element under room temperature (25 degreeC) of the solar cell module of the said Examples 1-18 was also excellent, and the output maintenance rate of the photovoltaic power was high.

  On the other hand, in Comparative Example 1, since the silane-modified linear low density polyethylene was not used for the filler layer, the solar cell module could not be manufactured without being in close contact with the transparent front substrate and the solar cell element. Moreover, in the comparative example 3, the adhesive strength was weak and the output maintenance rate was not able to be kept enough as a solar cell module.

(Evaluation of reusability)
About the said Examples 1-18 and Comparative Examples 2, 4, and 6, it evaluated based on the possibility of removal of a filler layer about the reusability of a transparent front substrate and a solar cell element.
The removal of the filler layer was performed by the following method.

1. First Method The obtained solar cell module was put into an oven at 200 ° C. After 5 minutes, the solar cell module was taken out of the oven and separated into a transparent front substrate, a solar cell element, and a back surface protection sheet to which a filler layer plasticized by heating was attached. The transparent front substrate to which the separated filler layer is adhered and the solar cell element are placed on a holding table, and soybean oil heated to 200 ° C. is caused to flow so as to contact the surface to which the filler layer is adhered, thereby transparent substrate and solar cell. The filler layer was removed from the device.

2. Second Method The obtained solar cell module was put into an oven at 200 ° C. After 5 minutes, the solar cell module was taken out of the oven and separated into a transparent front substrate, a solar cell element, and a back surface protection sheet to which a filler layer plasticized by heating was attached. The transparent front substrate and the solar cell element to which the separated filler layer was adhered were removed from the transparent front substrate and the solar cell element by a shot blasting method in a 200 ° C. atmosphere.

3. Third Method The obtained solar cell module was placed on a hot plate at 200 ° C. and heated. After 7 minutes, each was separated into a transparent front substrate, a solar cell element, and a back surface protection sheet to which a filler layer plasticized by heating adhered. The transparent front substrate and the solar cell element to which the separated filler layer was adhered were placed on the hot plate again, and the filler layer was wiped off with a cloth.

4). Fourth Method The obtained solar cell module was heated in a silicon oil bath heated to 180 ° C. After 20 minutes, the back protective sheet was peeled from the release layer plasticized by heating. Next, using the separation apparatus shown in FIG. 2, a transparent front substrate and a solar cell in which a φ0.15 mm wire is passed through a release layer plasticized by heating between the transparent front substrate and the solar cell element, and a filler layer is attached. Separated into elements. The transparent front substrate and the solar cell element to which the separated filler layer was adhered were immersed in a xylene bath heated to 80 ° C. and left for 24 hours. After standing, the solar cell element and the transparent front substrate were taken out, and the release layer remaining on the surface of the solar cell element and the transparent front substrate was gently wiped with a waste cloth.

5. Fifth Method The obtained solar cell module was heated in a silicon oil bath heated to 180 ° C. After 20 minutes, the back protective sheet was peeled from the release layer plasticized by heating. Next, using the separation apparatus shown in FIG. 2, a transparent front substrate and a solar cell in which a φ0.15 mm wire is passed through a release layer plasticized by heating between the transparent front substrate and the solar cell element, and a filler layer is attached. Separated into elements. The transparent front substrate to which the separated filler layer was adhered and the solar cell element were placed on a hot plate at 200 ° C., the softened release layer was dissolved with stearic acid, and the dissolved release layer was gently wiped with a waste cloth.

6). Sixth Method The obtained solar cell module was heated in a silicon oil bath heated to 180 ° C. After 20 minutes, the back protective sheet was peeled from the release layer plasticized by heating. Next, using the separation apparatus shown in FIG. 2, a transparent front substrate and a solar cell in which a φ0.15 mm wire is passed through a release layer plasticized by heating between the transparent front substrate and the solar cell element, and a filler layer is attached. Separated into elements.
The transparent front substrate and the solar cell element to which the separated filler layer was adhered were placed on a 200 ° C. hot plate, stearic acid was applied to the softened release layer, and the filler layer was removed. Thereafter, the solar cell element and the transparent front substrate with the filler layer remaining on the surface are immersed in a xylene bath heated to 80 ° C. and left for 240 hours to leave the release layer and the solar cell element, and the release layer and the transparent front substrate. Was peeled off.

7). Seventh Method The obtained solar cell module was heated in a silicon oil bath heated to 180 ° C. After 20 minutes, the back protective sheet was peeled from the release layer plasticized by heating. Next, using the separation apparatus shown in FIG. 2, a transparent front substrate and a solar cell in which a φ0.15 mm wire is passed through a release layer plasticized by heating between the transparent front substrate and the solar cell element, and a filler layer is attached. Separated into elements. The transparent front substrate and the solar cell element to which the separated filler layer was adhered were immersed in a xylene bath heated to 80 ° C. and left for 24 hours. After standing, the solar cell element having the filler layer remaining on the surface and the transparent front substrate were taken out, placed on a hot plate at 200 ° C., stearic acid was applied to the softened release layer, and the release layer was gently wiped with a waste cloth.

8). Eighth Method The obtained solar cell module was heated in a silicon oil bath heated to 190 ° C. After 2 minutes, the back protective sheet was peeled from the release layer plasticized by heating. Next, using the separation apparatus shown in FIG. 2, a transparent front substrate and a solar cell in which a φ0.08 mm wire is passed through a release layer plasticized by heating between the transparent front substrate and the solar cell element, and a filler layer is attached. Separated into elements. The transparent front substrate and the solar cell element to which the separated filler layer was adhered were placed on a hot plate at 190 ° C., and the softened release layer was gently wiped with a waste cloth.

9. Ninth Method The obtained solar cell module was heated in a silicone oil bath heated to 195 ° C. 2
After a minute, the back surface protective sheet was peeled from the release layer plasticized by heating. Next, using the separation apparatus shown in FIG. 2, a transparent front substrate and a solar cell in which a φ0.08 mm wire is passed through a release layer plasticized by heating between the transparent front substrate and the solar cell element, and a filler layer is attached. Separated into elements. The transparent front substrate and the solar cell element to which the separated filler layer was adhered were immersed in a xylene bath heated to 80 ° C. and left for 2 hours. After leaving, the peeling layer remaining on the surface of the solar cell element and the transparent front substrate in a xylene bath was gently wiped with a waste cloth.

10. Tenth Method The obtained solar cell module was immersed in a xylene bath heated to 80 ° C. and left for 20 hours. After leaving, the peeling layer remaining on the surface of the solar cell element and the transparent front substrate in a xylene bath was gently wiped with a waste cloth.

  Using the above ten methods, the transparent front substrate and the surface of the solar cell element taken out from the solar cell modules obtained in Examples 1 to 18 and Comparative Examples 2, 4, and 6 were visually observed, and the filler It was confirmed whether the layer was removed. In addition, when oil etc. adhered in the removal of the filler layer by the above-described method (separation step and removal step), it was washed with a solvent such as isopropyl alcohol as necessary.

  As a result of the evaluation, in Examples 9, 11, 12, and 15, it was somewhat difficult to remove the filler layer from the transparent front substrate and the solar cell element, but the solar cell modules obtained in Examples 1 to 18 In any of the above methods from the first method to the tenth method, it is possible to remove the filler layer from the transparent front substrate and the solar cell element, and it was recovered by removing the filler layer. The transparent front substrate and the solar cell element were reusable or recyclable.

  On the other hand, for the solar cell module obtained in Comparative Example 2, the solar cell module cannot be disassembled by any of the first method to the tenth method, and the transparent front surface from the solar cell module is not possible. The substrate and the solar cell element could not be collected and could not be reused or recycled. In Comparative Example 4, since the plasticity after softening was low, it was very difficult to remove the filler layer from the transparent front substrate and the solar cell element, and it was impossible to reuse or recycle. Further, in Comparative Example 6, it was extremely difficult to disassemble the solar cell module, and reuse or recycling was impossible.

It is a schematic sectional drawing which shows an example of the solar cell module of this invention. It is a schematic sectional drawing which shows an example of the separation apparatus in the manufacturing method of the reproduction | regeneration solar cell element of this invention. It is a perspective view which shows an example of the separation apparatus in the manufacturing method of the reproduction | regeneration solar cell element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solar cell element 2 ... Wiring electrode 3 ... Extraction electrode 4 ... Filler layer 4a ... Upper filler layer 4b ... Lower filler layer 5 ... Transparent front substrate 6 ... Back surface protection sheet 7 ... Outer frame 10 ... Solar cell module 21 … Wire fixing jig 22… Wire holding jig 23… Oil bath 24… Wire

Claims (18)

Solar cell used in a solar cell module in which a transparent front substrate, a wiring electrode and an extraction electrode are arranged, and a solar cell element in which a filler layer is arranged on at least one surface and a back surface protection sheet are laminated in this order. A module filler layer, wherein the filler layer comprises:
(A) The peel strength with the transparent front substrate measured in a 180 ° peel test at 25 ° C. is in the range of 1 N / 15 mm width to 150 N / 15 mm width, and (b) measured based on JIS standard K7206. (C) a thermoplastic resin having a melt mass flow rate measured in accordance with JIS standard K7210 within a range of 0.1 g / 10 min to 50 g / 10 min. Having a release layer as a main component,
The photovoltaic cell output retention rate before and after the test measured based on the rule (d) of the solar cell module using the filler layer is in the range of 80% to 100%. Module filler layer. The said filler layer distribute | arranged between the said transparent front substrate and the said solar cell element is (e) The total light transmittance exists in the range of 70%-100%, It is characterized by the above-mentioned. Filler layer for solar cell modules. The said peeling layer is arrange | positioned so that both surfaces of a solar cell element and a transparent front substrate may be contact | connected, The filler layer for solar cell modules of Claim 1 or Claim 2 characterized by the above-mentioned. The said filler layer is what the said peeling layer, the filling layer which consists of a resin composition different from the said peeling layer, and the said peeling layer were laminated | stacked in this order, The Claim 3 characterized by the above-mentioned. Filler layer for solar cell modules. The said filler layer is formed only by the said peeling layer, The filler layer for solar cell modules of Claim 3 characterized by the above-mentioned. After leaving the solar cell module in a hot and humid state at a temperature of 85 ° C. and a humidity of 85% for 1000 hours, the peel strength between the filler layer and the transparent front substrate measured in a 180 ° peel test under an atmosphere of 25 ° C. The filler layer for a solar cell module according to any one of claims 1 to 5, wherein the filler layer is in a range of 0.5 N / 15 mm width to 140 N / 15 mm width. The solar cell module filling according to any one of claims 1 to 6, wherein the thermoplastic resin is a copolymer of a polyethylene for polymerization and an ethylenically unsaturated silane compound. Material layer. The said thermoplastic resin contains the polyethylene for addition further, The filler layer for solar cell modules of Claim 7 characterized by the above-mentioned. The solar cell module filler layer according to claim 7 or 8, wherein the release layer contains Si (silicon) in an amount of 8 ppm to 3500 ppm as the amount of polymerized Si. 10. The solar cell module filler layer according to claim 1, wherein the release layer has a gel fraction of 30% or less. 11. The said peeling layer contains the at least 1 sort (s) of additive further chosen from the group which consists of a light stabilizer, a ultraviolet absorber, a heat stabilizer, and antioxidant from Claim 1 to Claim 10 characterized by the above-mentioned. The filler layer for solar cell modules according to claim 1. A solar cell module, wherein the solar cell module filler layer according to any one of claims 1 to 11 is disposed on at least one surface of a solar cell element. It is a manufacturing method of the reproduction | regeneration solar cell element which obtains a reproduction | regeneration solar cell element from the solar cell module described in Claim 12, Comprising: A solar cell module is heated to the temperature more than the softening point of the thermoplastic resin which is a constituent material of a peeling layer A regenerative sun comprising: a heating step for separating; a separation step for separating a solar cell element by peeling a release layer plasticized by heating; and a removing step for removing a filler layer attached to the solar cell element A battery element manufacturing method. The regeneration according to claim 13, wherein the removing step is performed by physical cleaning for physically removing the filler layer, chemical cleaning for chemically removing the filler layer, or a combination thereof. Manufacturing method of solar cell element. It is a manufacturing method of the reproduction | regeneration transparent front substrate which obtains a reproduction | regeneration transparent front substrate from the solar cell module described in Claim 12, Comprising: A solar cell module is heated to the temperature more than the softening point of the thermoplastic resin which is a constituent material of a peeling layer A regenerative transparency comprising: a heating step for separating; a separation step for peeling the release layer plasticized by heating to separate the transparent front substrate; and a removal step for removing the filler layer adhering to the transparent front substrate. Manufacturing method of front substrate. The regeneration according to claim 15, wherein the removing step is performed by physical cleaning for physically removing the filler layer, chemical cleaning for chemically removing the filler layer, or a combination thereof. A method for producing a transparent front substrate. It is a reuse method of the solar cell module which reuses a member from the solar cell module described in Claim 12, Comprising: A solar cell module is heated to the temperature more than the softening point of the thermoplastic resin which is a constituent material of a peeling layer. A method for reusing a solar cell module, comprising: a heating step; and a separation step of separating a transparent front substrate by peeling a release layer plasticized by heating. The method for reusing a solar cell module according to claim 17, wherein the separation step includes a back surface protection sheet separation step of separating a back surface protection sheet from the solar cell module.

Images