JPH09191116A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure scratch resistance, inflammability, initial filling properties and durability by coating the light incident side surface of a photovoltaic element with a transparent polymer resin coating material containing a fibrous inorganic compound comprising a nonwoven fabric of glass fiber coupled with acrylic resin having a transparent resin film layer on the front. SOLUTION: A photovoltaic element 101 is coated, on the light incident side surface, with a coating material of transparent orgarnic polymer resin 103 containing a fibrous inorganic compound 102 and having a transparent resin film layer 104 on the front. Preferably, the thickness of fibrous inorganic compound 102 is 50-200μm, the weight ratio of organic polymer resin B to one layer of fibrous inorganic compound A is 15-30, and the weight ratio A/B of coating material is 4-12. A nonwoven fabric of glass fiber is employed as the fibrous inorganic compound A and a synthetic resin is employed as a bonding material. Content of synthetic resin in the nonwoven fabric of glass fiber is 2-6% and an acryl resin is preferably employed as the synthetic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved solar cell module, and more particularly to at least a light incident side surface of a photovoltaic element coated with a transparent organic polymer resin containing a fibrous inorganic compound. Solar cell module.

[0002]

2. Description of the Related Art In recent years, awareness of environmental problems has been increasing worldwide. Above all, the fear of global warming caused by CO ₂ emission is serious, and the demand for clean energy is increasing more and more. Under these circumstances, solar cells are expected as a clean energy source because of their safety and ease of handling. By the way, there are various forms of solar cells.
Typical examples include crystalline silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, copper indium selenide solar cells, and compound semiconductor solar cells. Among them, thin film crystalline silicon solar cells, compound semiconductor solar cells, and amorphous silicon solar cells can be made large in area at a relatively low cost, and therefore research and development are being actively pursued in various fields.

Among these solar cells, a thin film solar cell typified by an amorphous silicon solar cell in which silicon is deposited on a conductive metal substrate and a transparent conductive layer is formed on the conductive metal substrate is lightweight and has impact resistance and flexibility. Since it is rich in nature, it is regarded as a promising future module form. However, unlike the case of depositing silicon on a glass substrate, it is necessary to cover the light incident side surface with a transparent coating material to protect the solar cells, and therefore the surface coating material requires the following items. . That is, it has good transparency (transparency) in the visible light region used for solar cell power generation, and protects the internal photovoltaic element from stress such as scratches and impacts from the outside (resistant). (Scratchability), it is required that the coating material itself is less deteriorated (weather resistance) and that the coating material itself is hard to burn (flame retardancy) while protecting the photovoltaic element in an outdoor installation environment.

As a surface coating layer satisfying such conditions, conventionally, a glass or acrylic resin film, a tetrafluoroethylene-ethylene copolymer film, an outermost surface coating material,
A transparent fluoride polymer thin film using a fluororesin film such as a polyvinyl fluoride film or a fluororesin paint is used, and various transparent organic materials such as ethylene-vinyl acetate copolymer are used as a filler inside the thin film. A polymer resin is used. Since the filler is inexpensive, it can be used in a large amount to protect the internal photovoltaic element, and EVA, which is known as a transparent organic polymer resin excellent in heat resistance and weather resistance, is used. Often. However, when glass is used as the outermost surface coating material, the glass is heavy, inflexible, and high in cost. Therefore, particularly in the case of an amorphous silicon solar cell, its characteristic features are light weight, flexibility, and The advantage of low cost is lost. Therefore, in the case of an amorphous silicon solar cell, a transparent fluoride polymer thin film is often used as the outermost surface coating material. The fluoride polymer thin film is rich in weather resistance and water repellency, and the decrease in conversion efficiency of the solar cell module due to the decrease in light transmittance due to yellowing / white turbidity due to resin deterioration or surface stains should be reduced. In addition, the solar cell module can be made more flexible.

However, when a resin film such as a fluoride polymer thin film is used as the outermost surface covering material, the scratch resistance is lower than that of a solar cell module using glass. It is often used as a surface coating material by impregnating a fibrous inorganic compound such as a glass fiber non-woven fabric. As a conventional example of using the fibrous inorganic compound as a surface coating material for a solar cell module, as described in U.S. Pat. S.
Department of Energy, Annu
al Report “Investigation o
f Test Methods, Material P
properties, and Processes f
or Solar Cell Encapsulant
s "(June 1979), page 10-1 (hereinafter referred to as Reference 1) and" Final Report ".
on the Investing of
Proposed Process Sequence
for the Array Automated
Assembly task "(Aug. 1980),
It is disclosed in page 233 (hereinafter referred to as Document 2). However, the purpose in this case is different from the improvement of scratch resistance, ensuring the distance between the solar cells and the glass as the surface coating material, ensuring the insulation resistance between the solar cells and the outside,
And it is to secure the exhaust passage in the vacuuming process. In addition, Japanese Patent Laid-Open No. Sho 60-1875 (hereinafter referred to as Document 3) discloses a glass on the outermost surface in a solar cell bonding manufacturing process in which cells move and adjacent cells contact each other or strings move. In order to solve the problem of squeezing out, it is disclosed that glass fiber is impregnated in the filler and used. Furthermore, Japanese Examined Japanese Patent Publication Sho 62-3
Japanese Patent No. 3756 (hereinafter referred to as Document 4) discloses a solar cell device in which a solar cell element is embedded in glass fiber reinforced plastic. FIG. 6 is a conventional example showing a coating configuration of such a solar cell module. In FIG. 6, 603 is a fluoride polymer thin film layer, 602 is a transparent organic polymer resin, and 601 is a photovoltaic element. More specifically, the fluoride polymer thin film layer 603 is an ETFE (ethylene-tetrafluoroethylene copolymer) film, P
It is a fluororesin film such as a VF (polyvinyl fluoride) film, and the transparent organic polymer resin 602 is EVA (ethylene-vinyl acetate copolymer), butyral resin or the like.

As described above, in the case of a so-called thin film solar cell such as an amorphous silicon solar cell, in order to take advantage of its features such as light weight, flexibility and low cost, the outermost surface coating material is It is desirable to use a resin film. However, compared to a solar cell module using glass, a solar cell module with a resin film layer on the outermost surface is vulnerable to external stresses such as scratches and impacts. For protection (internal protection), a transparent organic polymer resin used as a filler is often impregnated with a fibrous inorganic compound such as a glass fiber non-woven fabric to enhance the reinforcing effect and to be used as a surface coating material. Therefore, the amount of transparent organic polymer resin needs to be sufficient to impregnate the glass fiber nonwoven fabric. However, when the amount of the transparent organic polymer resin is large, there are the following problems. That is, it promotes a decrease in light transmittance of the surface coating material, which causes a decrease in conversion efficiency of the solar cell module. and again,
An organic polymer resin mainly used as a filler has a high combustion energy and is easily combustible, so thickening the filler reduces flame retardancy. In particular, when installing a solar cell module on the roof or using it as a roof-integrated solar cell module as a roof material,
It must be designated as a "non-combustible material" by the Minister of Construction, and must pass Class A in the flammability test prescribed by UL1703 in the United States.

As described above, it is desired to impregnate a glass fiber nonwoven fabric with the smallest possible amount of transparent organic polymer resin to ensure scratch resistance, flame retardancy, initial filling property and high conversion efficiency. However, in a solar cell module impregnated with a glass fiber nonwoven fabric, there is a problem that the surface coating material is colored and the conversion efficiency is lowered during long-term outdoor use at high temperature. This is because the synthetic resin used as the binder for the glass fiber nonwoven fabric is colored. In addition, in the coating material that secures these, the glass fiber is raised during long-term outdoor use and the surface coating material becomes opaque, so that the light transmittance to the photovoltaic element is reduced and the conversion efficiency is reduced. There is also. Such glass fiber embossing is particularly noticeable where there are large irregularities on the mounting member on the photovoltaic substrate. The reason for this is that by reducing the transparent organic polymer resin layer, the cross-linking agent contained in the resin is likely to volatilize to the outside and the crosslinking rate is lowered, so that the deterioration of the transparent organic polymer resin is easily promoted Can be considered. Since the transparent organic polymer resin and resin film as an adhesive and the transparent organic polymer resin as a filler and the photovoltaic element are not in contact with each other in the protruding portion of the glass fiber non-woven fabric, adhesion at their interface Power is reduced. In other words, it is easily affected by humidity from the outside, and moisture from the outside penetrates through the interface to deteriorate the characteristics of the solar cell, and a leak current is generated through such infiltrated water, resulting in a life of 20 years. There is a problem with the reliability of long-term use of the said solar cell module. Furthermore, when using a solar cell module as a roofing material, the reliability as a roof must be maintained for a very long period of 50 years, which is an even greater problem. As described above, Craneglass 230 (Cr
It is disclosed to use an an and Company). However, Craneglass 230 is
Since a vinyl acetate resin is used as a binder and the content thereof is 10% or more, coloring is remarkable under high temperature conditions. That is, the conversion efficiency of the solar cell module is reduced.

Further, in the above-mentioned document 3, a transparent cover glass is used as the outermost layer, and a glass fiber group in which two mats of long glass fibers are stacked directly above or below the photovoltaic element is arranged, and ethylene-acetic acid is used. A solar cell module in which a photovoltaic element is filled with a vinyl copolymer (EVA) is disclosed. However, in this case, glass is used as the outermost surface coating material, and the advantage cannot be utilized in the amorphous silicon solar cell module. Further, in the above-mentioned document 4, after arranging two glass fibers having a small number of end portions on both upper and lower surfaces of the photovoltaic element,
A solar cell module in which a resin is poured and the outermost layer is covered with a surface protective film is disclosed. However, in this case, there is only one glass fiber on the photovoltaic element, and in order to improve scratch resistance, the amount of organic polymer resin as a filler is increased or one nonwoven fabric is thick. I have to An increase in the amount of organic polymer resin makes it difficult to ensure flame retardancy, and the use of thick non-woven fabric causes the glass fibers to stand out during long-term outdoor exposure. Further, Document 4 does not mention about ensuring long-term reliability, and there is a point that a solution is required for embossing of glass fiber after long-term outdoor use.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the conventional solar cell module,
An object of the present invention is to provide an improved solar cell module having high reliability even in long-term outdoor use. Another object of the present invention is to secure scratch resistance, flame resistance, initial filling property,
Furthermore, the surface coating material can be colored during long-term outdoor exposure so that it can be secured for about 20 years without deteriorating the characteristics as a solar cell, and high reliability as a roof material can be obtained over a long-term use of about 50 years. An object of the present invention is to provide a highly reliable solar cell module in which glass fibers are not raised and the adhesive force between the outermost surface resin film and the transparent organic polymer resin can be secured.

[0010]

Means for Solving the Problems The present inventors have conducted extensive research and development to solve the above problems. As a result, it has been found that the above object can be achieved by the following. That is, at least the light-incident side surface of the photovoltaic element is provided with a transparent resin film layer on the outermost surface, in a solar cell module covered with a covering material made of a transparent organic polymer resin having a fibrous inorganic compound, A glass fiber non-woven fabric is formed by binding the fibrous inorganic compound with an acrylic resin.

[0011]

The solar cell module based on the above-mentioned structure includes the following aspects and has a remarkable effect. (1) The coating material has excellent heat resistance and weather resistance with little discoloration at high temperatures or long-term outdoor use. That is, by using an acrylic resin that is less discolored by light and heat as a binder, it is possible to obtain a solar cell module in which the conversion efficiency is less likely to decrease even when used for a long time at high temperatures or outdoors. (2) By the presence of the fibrous inorganic compound directly above and / or immediately below the organic polymer resin,
Since the fibrous inorganic compound does not rise and the adhesiveness between the outermost surface resin film and the transparent organic polymer resin layer, and the transparent organic polymer resin layer and the photovoltaic element can be secured, the coating material can be used for a long period of time. It is possible to obtain a highly reliable solar cell module in which the light transmittance does not decrease. Also, high scratch resistance can be secured. Specifically, for example, compared with the conventional configuration having one layer of fibrous inorganic compound, the air in the filler can be sufficiently degassed and the initial degassing property is excellent, and sufficient degassing is performed for a long time. Also during use, the fibrous inorganic compound is suppressed from being raised. Further, by using two or more layers of fibrous inorganic compound,
The fibrous inorganic compound is homogenized. (3) The thickness of the fibrous inorganic compound is 50 μm to 200 μm
By setting m, the effect of the above (2) can be further enhanced. That is, the migration of the synthetic resin used as the binder between the fibers is suppressed, and the fibrous inorganic compound is in a stable state. (4) Since the weight ratio of the transparent organic polymer resin to the fibrous inorganic compound is 4 to 12, a small amount of the transparent organic polymer resin provides a coating material having excellent scratch resistance. That is, by reinforcing the transparent organic polymer resin with the fibrous inorganic compound, the thickness of the transparent organic polymer resin can be reduced while ensuring scratch resistance.

(5) By setting the content of the acrylic resin in the fibrous inorganic compound to 3% to 6.0%, the effects of (1) and (2) above can be further enhanced. The fluffiness of the fibrous inorganic compound is suppressed and it becomes easy to handle. That is, depolymerization of the synthetic resin with respect to the fibrous inorganic compound can be minimized. (6) By setting the wetting index of the outermost surface transparent resin film layer on the photovoltaic element side to be 40 dyne to 45 dyne, a coating material with excellent adhesive strength and high long-term reliability can be obtained. In other words, the resin film and the transparent organic polymer resin are optimized to improve the adhesive strength between the resin film and the transparent organic polymer resin in the initial stage, and also the coating that has high reliability in the adhesive strength after long-term outdoor exposure. It becomes a material. (7) Since the resin film is a fluoride polymer, the coating has excellent weather resistance. That is, the weather resistance of the fluoride polymer is desirably exhibited in combination with the transparent organic polymer resin as the filler. (8) The tetrafluoroethylene-ethylene copolymer is formed by converting the fluoride polymer into a tetrafluoroethylene-ethylene copolymer.
It is a coating material that makes full use of the weather resistance, transparency, and mechanical strength of the ethylene copolymer.

(9) ASTM D- of transparent resin film
By setting the tensile elongation at break in the 882 test method to 200% to 800% in both the longitudinal direction and the lateral direction, the outermost surface coating material does not have cracks, so water from the outside is prevented from entering and electrical insulation from the outside is achieved. Can be secured. (10) By using an ethylene-vinyl acetate copolymer (EVA) as the transparent organic polymer resin, the above-mentioned effects can be obtained without significantly changing the configuration of the conventional coating material for the solar cell module. it can. (11) By treating the transparent organic polymer resin with a coupling agent, the adhesive strength with the outermost surface transparent resin film, the photovoltaic element substrate and the fibrous inorganic compound is improved, and high reliability as a coating material is obtained. Can be secured. (12) By treating the fibrous inorganic compound with a coupling agent, it is possible to further improve the adhesive force with the transparent organic polymer resin and prevent the fibrous inorganic compound from rising. (13) The thickness of the transparent organic polymer resin is 200 μm to 8
When it is 00 μm, the coating material has excellent flame retardancy. That is, flame retardancy can be ensured by reducing the amount of organic polymer resin having high combustion energy. (14) The solar cell module can be easily manufactured with a low-cost device by manufacturing by bonding the solar cell module by a single vacuum exhaust method. (15) The solar cell module is manufactured by stacking and laminating the photovoltaic element with the light-receiving surface side facing upward,
With the minimum amount of transparent organic polymer resin, the irregularities on the light-receiving surface side of the photovoltaic element can be embedded. That is, the followability of the coating material on the light receiving surface side with respect to the irregularities on the surface of the photovoltaic element is improved.

[0014]

Embodiment Examples The present invention will be described with reference to the following embodiment examples. FIG. 1 is a schematic configuration diagram of an example of the solar cell module of the present invention. In FIG. 1, 101 is a photovoltaic element,
Reference numeral 102 is a fibrous inorganic compound, 103 is a transparent organic polymer resin as a surface filler, 104 is a transparent resin film located on the outermost surface, 105 is a back surface filler, and 106 is a back surface insulating film. Light from the outside is incident from the outermost film 104, reaches the photovoltaic element 101, and the generated electromotive force is extracted to the outside from an output terminal (not shown). The photovoltaic element 101 in the solar cell module of the present invention is typically one in which a semiconductor photoactive layer as a light conversion member and a transparent conductive layer are formed on a conductive substrate. A schematic configuration diagram as an example thereof is shown in FIG. In FIG. 2, 201 is a conductive substrate, 202 is a back reflection layer, 2
03 is a semiconductor photoactive layer, 204 is a transparent conductive layer, 205 is a current collecting electrode, and 206 is an output terminal.

The conductive substrate 201 serves as a substrate for the photovoltaic element, and also serves as a lower electrode. Materials include silicon, tantalum, molybdenum, tungsten,
Examples include stainless steel, aluminum, copper, titanium, carbon sheets, lead-plated steel sheets, resin films having a conductive layer formed thereon, and ceramics. A metal layer, a metal oxide layer, or a metal layer and a metal oxide layer may be formed as the back surface reflection layer 202 on the conductive substrate 201. For the metal layer, for example, Ti, Cr, Mo, W, A
1, Ag, Ni, etc. are used. For the metal oxide layer, for example, ZnO, TiO ₂ , SnO ₂ or the like is used. These metal layer and metal oxide layer can be formed by a resistance heating vapor deposition method, an electron beam vapor deposition method, a sputtering method, or the like. The semiconductor photoactive layer 203 is a portion that performs photoelectric conversion, and as a specific material, pn junction type polycrystalline silicon, pin junction type amorphous silicon, or C
uInSe ₂ , CuInS ₂ , GaAs, CdS / Cu ₂
S, CdS / CdTe, CdS / InP, CdTe / C
Examples thereof include compound semiconductors such as u ₂ Te. The semiconductor photoactive layer can be formed by a known method. That is, in the case of polycrystalline silicon, sheeting of molten silicon or heat treatment of amorphous silicon, plasma CVD using silane gas as a raw material in the case of amorphous silicon, ion plating, ion beam deposition, vacuum in the case of compound semiconductors. It can be formed by a vapor deposition method, a sputtering method, an electrodeposition method or the like.

The transparent conductive layer 204 functions as the upper electrode of the solar cell. As the material used, for example, I
_{n 2 O 3, SnO 2,} In 2 O 3 -SnO 2 (ITO), Zn
There are O, TiO ₂ , Cd ₂ SnO ₄ , and a crystalline semiconductor layer doped with a high concentration of impurities. Examples of the formation method include resistance heating evaporation, sputtering, spraying, CVD, and impurity diffusion. A grid-shaped collector electrode 205 (grid) may be provided on the transparent conductive layer in order to collect current efficiently. Specific materials for the collector electrode 205 include, for example, Ti, Cr, Mo, W, Al, Ag, N.
Examples of the conductive paste include i, Cu, Sn, and silver paste. As a method of forming the collecting electrode 205, sputtering using a mask pattern, resistance heating, a CVD method, a method of depositing a metal film on the entire surface and then removing an unnecessary portion by etching, and patterning by a photo CVD directly There are a method of forming an electrode pattern, a method of plating after forming a negative pattern mask of a grid electrode pattern, a method of printing a conductive paste, and the like. As the conductive paste, a fine powder of silver, gold, copper, nickel, carbon or the like dispersed in a binder polymer is usually used. Examples of the binder polymer include resins such as polyester, epoxy, acrylic, alkyd, polyvinyl acetate, rubber, urethane, and phenol.

The output terminal 206 is attached to the conductive substrate and the collecting electrode in order to extract the electromotive force. A method of spot-welding a metal body such as a copper tab or joining with a solder 207 is used for the conductive substrate, and a method of electrically connecting the metal body with a conductive paste or solder 207 is used for the collecting electrode. Note that it is desirable to provide an insulator 208 in order to prevent the output terminal from coming into contact with the conductive metal substrate or the semiconductor layer and short-circuiting when the collector terminal 205 is attached to the collector electrode 205. The photovoltaic elements formed as described above are connected in series or in parallel depending on the desired voltage or current. In the case of series connection, the plus side and the minus side of the output terminal are connected, and in the case of parallel connection, the same polarity is connected. Alternatively, a desired voltage or current can be obtained by integrating a photovoltaic element on an insulated substrate. The material of the metal member used for connecting the output terminal and the element may be selected from copper, silver, solder, nickel, zinc and tin in consideration of high conductivity, solderability and cost. desirable.

The outermost surface resin film 104, the surface filler 103 and the fibrous inorganic compound 102 used in the present invention will be described below. The surface filler 103 is necessary to cover the irregularities of the photovoltaic element with a resin, protect the element from a harsh external environment such as temperature change, humidity, and impact, and secure the adhesion between the surface film and the element. However, since flame retardancy is also required at the same time, by containing a fibrous inorganic compound, the amount of the filler is reduced, so that the surface filling becomes a flame retardant material while ensuring scratch resistance. It is desirable to use wood. However, when the content of the fibrous inorganic compound with respect to the transparent organic polymer resin becomes high, as a harmful effect, peeling occurs between the fibrous inorganic compound and the transparent organic polymer resin in long-term outdoor exposure, and the fibrous inorganic compound is raised. The problem of happening occurs.
That is, in order to secure flame retardancy, and to improve the light transmittance and the conversion efficiency of the solar cell module, it is preferable that the thickness of the filler is thin, the mechanical strength, and the unevenness of the photovoltaic element. In order to obtain a highly reliable coating material that does not cause the fibrous inorganic compound to stand out during long-term outdoor exposure, it must be thick to some extent. Specifically, the thickness of the transparent organic polymer resin in the solar cell module is preferably 200 μm to 800 μm. If the thickness of the transparent organic polymer resin is 200 μm or less, the fibrous inorganic compound for obtaining sufficient scratch resistance cannot be contained, and if it is 800 μm or more, flame retardancy cannot be ensured.

The fibrous inorganic compound 102 has a thickness of 50 μm.
To 200 μm, the weight ratio of the organic polymer resin to the fibrous inorganic compound layer is 15 to 30, and the weight ratio of the organic polymer resin to the fibrous inorganic compound in the coating material is 4 to 12. preferable. If the thickness of the fibrous inorganic compound is 50 μm or less, it will be very difficult to produce the fibrous inorganic compound, and in order to obtain the reinforcing effect of the covering material, a great number of fibrous inorganic compounds must be laminated. Therefore, the process is complicated when manufacturing a solar cell module. When the thickness of the fibrous inorganic compound is 200 μm or more, the acrylic resin contained as an adhesive in the fibrous inorganic compound migrates, and a stable fibrous inorganic compound cannot be obtained. This means that in the portion where the acrylic resin is rich due to migration, depolymerization of the acrylic resin occurs during long-term outdoor use, and since there is a void in that portion, it is easily affected by humidity from the outside. Furthermore, moisture from the outside penetrates through the interface and deteriorates the characteristics of the solar cell. The fibrous inorganic compound used is a fibrous inorganic compound having a fiber diameter of 4 μm to 15 μm or a mixture of these fibrous inorganic compounds, and the fiber length thereof is preferably 1 mm to 1000 mm. If the weight ratio of the organic polymer resin to the fibrous inorganic compound in the coating material is 4 or less, the fibrous inorganic compound cannot be sufficiently filled with the transparent organic polymer resin as the filler, and 12 or more. If so, the reinforcing effect is small and scratch resistance cannot be secured.

When the solar cell module is expected to be used in a more severe environment, it is preferable to improve the adhesion between the filler and the photovoltaic element or the surface film.
The adhesion can be improved by adding a silane coupling agent or an organic titanate compound to the filler. The addition amount thereof is preferably 0.1 to 3 parts by weight, more preferably 0.25 to 1 part by weight, relative to 100 parts by weight of the filler resin. Furthermore, in order to improve the adhesiveness between the fibrous inorganic compound and the filler, the surface of the fibrous inorganic compound is subjected to a silane coupling treatment to improve the adhesiveness between the fibrous inorganic compound and the filler, and to improve the long-term use of the fiber. It is also possible to suppress the protrusion of the particulate inorganic compound.
Specific examples of the silane coupling agent include vinyltrichlorosilane and vinyltris (β-methoxyethoxy).
Silane; vinyltriethoxysilane; vinyltrimethoxysilane; γ-methacryloxypropyltrimethoxysilane; β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; γ-glycidoxypropylmethyldiethoxysilane; N-β (Aminoethyl) γ-aminopropyltrimethoxysilane; N-β (aminoethyl)
γ-aminopropylmethyldimethoxysilane; γ-aminopropyltriethoxysilane; N-phenyl-γ-aminopropyltrimethoxysilane; γ-mercaptopropyltrimethoxysilane; γ-chloropropyltrimethoxysilane and the like.

As the fibrous inorganic compound, a glass fiber non-woven fabric is generally used. Generally, a synthetic resin is used as a binder for binding glass fibers into a glass fiber nonwoven fabric. Specifically, the content of the synthetic resin in the glass fiber nonwoven fabric is preferably 2.0% to 6.0%,
3.0% to 4.5% is more preferable. Furthermore, it is preferable to use an acrylic resin as the synthetic resin. When the content is 2.0% or less, it is difficult to bind the glass fibers, which is difficult to manufacture the glass fiber non-woven fabric, and there is a problem that the glass fibers are often fluffed in handling. When the rate is 6.0% or more, the rate of depolymerization of the synthetic resin increases during long-term use, and the number of voids generated in that portion also increases. Acrylic resin has little discoloration due to light and heat, so using it as a binder means that it suppresses discoloration of the light-receiving surface of the solar cell module, which is a coating material with excellent heat resistance and weather resistance. Becomes

As the resin satisfying the weather resistance, adhesiveness, filling property, heat resistance, cold resistance, impact resistance and the like required for the filler, ethylene-vinyl acetate copolymer (EVA), ethylene-
Examples thereof include methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), polyolefin resins such as butyral resin, urethane resins, and silicone resins. Among these, EVA is particularly preferable because it has well-balanced physical properties for use in solar cells. However, since the heat deformation temperature is low as it is, it easily deforms and creeps under high temperature use. Therefore, it is desirable to increase the heat resistance by crosslinking. In the case of EVA, it is common to crosslink with an organic peroxide. The cross-linking by the organic peroxide is performed by free radicals generated from the organic peroxide extracting hydrogen or halogen atoms in the resin to form a C—C bond. Thermal decomposition, redox decomposition and ionic decomposition are known as methods for activating organic peroxides. Generally, the thermal decomposition method is preferred.

Examples of the organic peroxide include hydroperoxide type, dialkyl (allyl) peroxide type, diacyl peroxide type, peroxyketal type, peroxyester type, peroxycarbonate type and ketone peroxide type. Specific examples of the hydroperoxide system include t-butyl peroxide; 1,
1,3,3-Tetramethylbutyl peroxide; p-menthane hydroperoxide; cumene hydroperoxide; p-cymene hydroperoxide; diisopropylbenzene peroxide; 2,5-dimethylhexane 2,
5-dihydroperoxide; cyclohexane peroxide; 3,3,5-trimethylhexanone peroxide and the like. Specific examples of the dialkyl (allyl) peroxide type include di-t-butyl peroxide; dicumyl peroxide; t-butylcumyl peroxide.

Specific examples of the diacyl peroxide type include diacetyl peroxide; dipropionyl peroxide; diisobutyryl peroxide; dioctanoyl peroxide; didecanoyl peroxide; dilauroyl peroxide; bis (3,3,5-trimethylhexanoyl). ) Peroxide; benzoyl peroxide; m-toluyl peroxide; p-chlorobenzoyl peroxide; 2,4-dichlorobenzoyl peroxide; peroxysuccinic acid and the like.

Specific examples of the peroxyketal system include:
2,2-di-t-butylperoxybutane; 1,1-di-t-butylperoxycyclohexane; 1,1-di-
(T-Butylperoxy) -3,3,5-trimethylcyclohexane; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; 2,5-dimethyl-2,5
-Di (t-butylperoxy) hexyne-3; 1,3-
Di (t-butylperoxyisopropyl) benzene;
2,5-Dimethyl-2,5-dibenzoylperoxyhexane; 2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3; n-butyl-4,4-bis (t-butylperoxy) valerate And so on.

Specific examples of the peroxy ester type are:
t-butyl peroxyacetate; t-butyl peroxyisobutyrate; t-butyl peroxypivalate;
t-butyl peroxy neodecanoate; t-butyl peroxy 3,3,5-trimethyl hesanoate; t-butyl peroxy 2-ethylhexanoate; (1,1,
3,3-Tetramethylbutylperoxy) 2-ethylhexanoate; t-butylperoxylaurate; t-
Butyl peroxy benzoate; di (t-butyl peroxy) adipate; 2,5-dimethyl 2,5-di (peroxy 2-ethylhexanoyl) hexane; di (t-butyl peroxy) isophthalate; t-butyl peroxymalate; Acetyl cyclohexyl sulfonyl peroxide and the like.

Specific examples of the peroxycarbonate system include t-butylperoxyisopropyl carbonate;
Di-n-propyl peroxydicarbonate; di-se
c-Butylperoxydicarbonate; di (isopropylperoxy) dicarbonate; di (2-ethylhexylperoxy) dicarbonate; di (2-ethoxyethylperoxy) dicarbonate; di (methoxidepropylperoxy) carbonate; di (3-methoxybutylperoxy) ) Dicarbonate; bis- (4-t-butylcyclohexylperoxy) dicarbonate and the like. Specific examples of the ketone peroxide type include acetylacetone peroxide; methyl ethyl ketone peroxide; methyl isobutyl ketone peroxide; ketone peroxide. In addition to these, vinyl tris (t
-Butylperoxy) silane can also be used.

The amount of the organic peroxide added is the filler resin 10
It is 0.5 to 5 parts by weight with respect to 0 parts by weight. By using the organic peroxide in combination with the filler, it is possible to perform crosslinking and thermocompression bonding while heating under pressure. The heating temperature and time can be determined by the thermal decomposition temperature characteristics of each organic peroxide. Generally, thermal decomposition is more than 90%, preferably 95
The heating and pressurization is terminated when the temperature and time for advancing by 10% or more are reached. The gel fraction of the resulting filler is preferably 80% or more, more preferably 90% or more. The gel fraction of 80% or less means that the resin contains a large amount of non-crystalline portions, that is, the deterioration of the resin is promoted. In order to efficiently carry out the crosslinking reaction, it is desirable to use triallyl isocyanurate (TAIC) called a crosslinking aid. The amount of addition is generally 100% filler resin.
It is 1 to 5 parts by weight with respect to parts by weight.

The material of the filler used in the present invention is excellent in weather resistance, but an ultraviolet absorber may be used in combination for further improving weather resistance or protecting the lower layer of the filler. . The amount added is about 0.1 to 0.5 parts by weight with respect to 100 parts by weight of the resin. As the ultraviolet absorber, known compounds of salicylic acid type, benzophenone type, benzotriazole type and cyanoacrylate type can be used. Specific examples of the salicylic acid type include phenyl salicylate; p-tert-butylphenyl salicylate; p-octylphenyl salicylate.

Specific examples of benzophenone-based compounds include 2,
4-dihydroxybenzophenone; 2-hydroxy-4
-Methoxybenzophenone; 2-hydroxy-4-octoxybenzophenone; 2-hydroxy-4-dodecyloxybenzophenone; 2,2'-dihydroxy-4-
Methoxybenzophenone; 2,2'-dihydroxy-
4,4'-dimethoxybenzophenone;2-hydroxy-4-methoxy-5-sulfobenzophenone; bis (2
-Methoxy-4-hydroxy-5-benzophenone) methane and the like.

Specific examples of the benzotriazole type compounds include:
2- (2'-hydroxy-5'-methylphenyl) benzotriazole; 2- (2'-hydroxy-5'-te
rt-Butylphenyl) benzotriazole; 2-
(2'-Hydroxy-3 ', 5'-di.tert-butylphenyl) benzotriazole; 2- (2'-hydroxy-3'-tert-butyl-5-methylphenyl)
-5-chlorobenzotriazole; 2- (2'-hydroxy-3 ', 5'-di.tert-butylphenyl)-
5-chlorobenzotriazole; 2- (2'-hydroxy-3 ', 5'-di.tert-amylluphenyl) benzotriazole; 2- {2'-hydroxy-3'-
(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl} benzotriazole; 2,2-methylenebis {4- (1,1,3,3-tetramethylbutyl) -6 -(2H-benzotriazol-2-yl) phenol} and the like. Specific examples of the cyanoacrylate type include 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate; ethyl-2
-Cyano-3,3'-diphenyl acrylate and the like. One or more of these UV absorbers can be added.

A hindered amine-based light stabilizer can be used as a method for imparting weather resistance in addition to the above ultraviolet absorber. A hindered amine-based light stabilizer does not absorb ultraviolet rays unlike an ultraviolet absorber, but exhibits a remarkable synergistic effect when used in combination with an ultraviolet absorber. The amount added is generally about 0.1 to 0.3 parts by weight with respect to 100 parts by weight of the resin. Of course, some other than hindered amines function as light stabilizers, but are often colored, which is not desirable for the filler of the present invention. Examples of the hindered amine light stabilizer include dimethyl-1- (2-hydroxyethyl) -4-hydroxy-succinate.
2,2,6,6-Tetramethylpiperidine polycondensate; poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl}
{(2,2,6,6-tetramethyl-4-piperidyl)
Imino {hexamethylene {2,2,6,6-tetramethyl-4-piperidyl) imino}]; N, N'-bis (3-aminopropyl) ethylenediamine · 2,4-bis [N-butyl-N -(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,
3,5-triazine condensate; bis (2,2,6,6-tetramethyl-4-piperidyl) sebalate;
5-di-tert-4-hydroxybenzyl) -2-n
-Bis (1,2,2,6,6-pentamethyl-4-piperidyl) butylmalonate and the like can be used.

It is preferable to use a low-volatile ultraviolet absorber in consideration of the use environment of the solar cell module. If a light stabilizer is added in addition to the ultraviolet absorber, the filler becomes more stable to light. Further, an antioxidant can be added to improve heat resistance and heat workability. The addition amount is preferably 0.1 to 1 part by weight with respect to 100 parts by weight of the resin. As such an antioxidant, a monophenol type, a bisphenol type, a polymer type phenol type, a sulfur type or a phosphoric acid type can be used. Specific examples of the monophenol type include 2,6-di-ter.
t-butyl-p-cresol; butylated hydroxyanisole; 2,6-di-tert-butyl-4-ethylphenol and the like.

Specific examples of bisphenol-based compounds include 2,
2'-methylene-bis- (4-methyl-6-tert-
Butylphenol); 2,2'-methylene-bis- (4
-Ethyl-6-tert-butylphenol); 4,
4'-thiobis- (3-methyl-6-tert-butylphenol); 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol); 3,9-bis {1,1-dimethyl- 2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl} 2,4,8,10-tetraoxaspiro} 5,5 undecane and the like.

Specific examples of the high-molecular phenol type include:
1,1,3-tris- (2-methyl-4-hydroxy-
5-tert-butylphenyl) butane; 1,3,5-
Trimethyl-2,4,6-tris (3,5-di-ter
t-butyl-4-hydroxybenzyl) benzene; tetrakis- {methylene-3- (3 ', 5'-di-tert)
-Butyl-4'-hydroxyphenyl) propionate} methane; bis (3,3'-bis-4'-hydroxy-3'-tert-butylphenyl) butyric acid} glycol ester; 1,3,5-tris (3 ',
5'-di-tert-butyl-4'-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5
H) trione; such as triphenol (vitamin E).

Specific examples of sulfur compounds include dilauryl thiodipropionate; dimyristyl thiodipropionate; distearyl thiopropionate. Specific examples of the phosphoric acid system include triphenyl phosphite; diphenyl isodecyl phosphite; phenyl diisodecyl phosphite; 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite. Phyto; cyclic neopentane tetrayl bis (octadecyl phosphite); tris (mono and / or diphenyl phosphite; diisodecyl pentaerythritol diphosphite; 9,10-dihydro-9-oxa-10-phosphaphenathrene-10
-Oxide; 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9
-Oxa-10-phosphaphenanthrene-10-oxide; 10-decyloxy-9,10-dihydro-9-
Oxa-10-phosphaphenanthrene; cyclic neopentanetetraylbis (2,4-di-tert-
Butylphenyl) phosphite; cyclic neopentanetetraylbis (2,6-di-tert-methylphenyl) phosphite; 2,2-methylenebis (4,6)
-Tert-butylphenyl) octyl phosphite and the like.

In order to suppress the decrease in the amount of light reaching the photovoltaic element as much as possible, the surface filler must be transparent, and specifically, the light transmittance is 80 in the visible light wavelength range of 400 nm to 800 nm. % Or more, and more preferably 90% or more. Also,
In order to facilitate the incidence of light from the atmosphere, the refractive index at 25 ° C. is preferably 1.1 to 2.0,
More preferably, it is 1.1 to 1.6. Since the surface resin film 104 used in the present invention is located at the outermost surface layer of the solar cell module, it has weather resistance, stain resistance, mechanical strength, and other properties for ensuring long-term reliability in outdoor exposure of the solar cell module. is necessary. Examples of the resin film used in the present invention include fluororesin and acrylic resin. These middle fluororesins are particularly preferable because they are excellent in weather resistance and stain resistance. Specific examples of the fluororesin include polyvinylidene fluoride resin, polyvinyl fluoride resin and tetrafluoroethylene-ethylene copolymer. Polyvinylidene fluoride resin is excellent in terms of weather resistance, but ethylene tetrafluoride-ethylene copolymer is excellent in terms of compatibility between weather resistance and mechanical strength and transparency.

In order to improve the adhesiveness with the filler, it is desirable to perform surface treatment such as corona treatment, plasma treatment, ozone treatment, UV irradiation, electron beam irradiation and flame treatment on the surface film. Specifically, the wetting index on the photovoltaic element side is preferably 35 dyne. When the wetting index is 35 dyne or less, the adhesive force between the resin film and the filler is insufficient, so that the filler and the resin film are separated from each other. Further, since the stretched film of the resin film causes cracks, it is preferable that the stretched film is not stretched. Specifically, ASTM
The tensile breaking elongation in the D-882 test method is preferably 200% to 800% in both the longitudinal direction and the transverse direction.

The insulating film 106 is used for the photovoltaic element 10
It is necessary to maintain electrical insulation between the conductive metal substrate 1 and the outside. As a material, it is possible to secure sufficient electrical insulation with a conductive metal substrate, and also has excellent long-term durability and thermal expansion,
A material having flexibility and capable of withstanding heat shrinkage is preferable. Examples of suitable insulating films include nylon, polyethylene terephthalate, and polycarbonate. The filling material 105 on the back surface is the photovoltaic element 1.
01 for bonding the insulating film 106 on the back surface. As the material, a material that can secure sufficient adhesiveness to the conductive substrate, has excellent long-term durability, can withstand thermal expansion and thermal contraction, and has flexibility is preferable. Suitable materials used include hot-melt materials such as EVA and polyvinyl butyral, double-sided tapes, and epoxy adhesives having flexibility. Also, the surface filler 1
Often the same material as 03. A reinforcing plate may be attached to the outside of the coating film on the back surface in order to increase the mechanical strength of the solar cell module or to prevent distortion and warpage due to temperature change. For example, a steel plate, a plastic plate, or an FRP (glass fiber reinforced plastic) plate is preferable.

In order to obtain a solar cell module using the above-mentioned photovoltaic element, filler, front surface resin film, and back surface coating material, for example, the following method can be adopted. In order to cover the light receiving surface of the photovoltaic element, a method is generally used in which a filler 103 molded in a sheet shape is prepared and heat-pressed on the front and back of the element. The coating structure of the solar cell module is as shown in FIG. That is, the photovoltaic element 101, the fibrous inorganic compound 102, the filling material 103, the front surface resin film 104, the back surface filling material 105, and the insulating film 106 are laminated in the order shown in the figure or in the reverse order, and are thermocompression bonded. However, in order to coat the photovoltaic element with a small amount of the filler, it is more preferable to stack the resin films in the order shown in the drawing. Further, by providing continuous two or more layers of the fibrous inorganic compound directly above and directly below the filler, the degassing property is improved, and the solar cell module is provided with flame retardancy, scratch resistance, heat resistance, and weather resistance. be able to. Specifically, by using two or more layers of fibrous inorganic compound, it is possible to secure higher degassing property as compared with the case of one layer, and to make the fibrous inorganic compound a highly uniform fibrous inorganic compound. Therefore, scratch resistance is also improved. When the reinforcing plate is provided, it may be superposed on the insulating film via an adhesive and pressure-bonded, which may be performed simultaneously with the above process or after the process. In addition,
The heating temperature and heating time at the time of pressure bonding are determined by the temperature and time at which the crosslinking reaction proceeds sufficiently. As the thermocompression bonding method, conventionally known double vacuum evacuation method, single vacuum evacuation method, roll lamination and the like can be selected and used. Above all, the thermocompression bonding by the single vacuum evacuation method is a preferable method because a solar cell module can be easily manufactured with a low-cost device.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. The present invention is not limited to these examples.

[0042]

Embodiment 1

[Production of Photovoltaic Element] An amorphous silicon (a-Si) solar cell (photovoltaic element) having the structure shown in FIG. 2 was produced as follows. Washed stainless steel substrate 201
An Al layer (thickness 5000 Å) and a ZnO layer (thickness 5000 Å) were sequentially formed on the upper surface as a back reflection layer 202 by a sputtering method. Then, an n-type a-Si layer is formed from a mixed gas of SiH ₄ , PH ₃ and H ₂ by a plasma CVD method into SiH ₄
The i-type a-Si layer from a mixed gas between H _2, SiH ₄ and BF
_A p-type microcrystalline μc-Si layer is formed from a mixed gas of ₃ and H ₂ , and the n-layer film thickness 150 Å / i-layer film thickness 4000 Å / p-layer film thickness 100 Å / n-layer film thickness 100 Å / i-layer film thickness 800 Å / A tandem-type a-Si photoelectric conversion semiconductor layer 203 having a layer structure with a p-layer thickness of 100Å was formed. Next, as the transparent conductive layer 204, an In ₂ O ₃ thin film (film thickness 700 Å) was formed by vapor-depositing In in an O ₂ atmosphere by a resistance heating method. Furthermore, the grid electrode 205 for current collection was formed by screen printing of silver paste. Then, the negative terminal 2
A copper tab was attached to the stainless steel substrate as the 06a using the solder 207, and a tin foil tape was attached to the collector electrode 205 as the positive side terminal 206b with the solder 207. Thus, a plurality of photovoltaic elements were obtained.

[0043]

[Fabrication of Cell Block] A plurality of photovoltaic elements obtained as described above were connected in series to fabricate a solar cell block having a structure shown in FIG. That is, after arranging the photovoltaic elements,
The positive side terminal 308 of one element of the adjacent elements and the negative side terminal 309 of the other element were connected by a copper tab 307 using solder. As a result, a solar cell block in which three elements were serialized was obtained. At this time, the copper tab connected to the output terminal of the end element was turned to the back surface so that the output could be taken out from the hole of the back surface coating layer described later.

[0044]

[Modularization] EVA sheet 403 (manufactured by Springborn Laboratories, trade name: PHOTOCAP A9918P ^*) on the light-receiving surface side of the cell block obtained above ^.
/ 200 rms / 936, thickness 460 μm) and glass fiber non-woven fabric (manufactured by Honshu Paper Co., Ltd., trade name: Grasper GMC)
-00-020 (B), basis weight 20 g / m ² , thickness 10
0 μm, binder acrylic resin 4.0 wt. % Content) 40
2 and non-stretched ETFE film 404 (manufactured by DuPont, trade name: non-stretched Tefzel film, thickness 50 microns), an insulating film 405 (manufactured by DuPont, trade name: Dartec, thickness 75 μm) as a back surface coating material, The same EVA sheet 403 as that used for the surface coating material as an adhesive, and a galvanized steel plate 406 painted in black as a reinforcing plate (zinc plated steel plate, thickness 0.27 mm)
The ETFE film 404 / glass fiber non-woven fabric 402
/ Glass fiber nonwoven fabric 402 / EVA403 / glass fiber nonwoven fabric 402 / glass fiber nonwoven fabric 402 / cell block 401 / EVA403 / insulating film 405 / EVA4
03 / Reinforcing plate 406 is sequentially stacked so that the ETFE film 404 is on top, and while being degassed under pressure using a single vacuum evacuation laminating device, placed in an oven preheated to 150 ° C. for 100 minutes. 30 at 150 ° C
A solar cell module was obtained by heating for a minute. The EVA sheet used here was composed of 100 parts by weight of EVA resin (33% vinyl acetate content) and 1.5 parts by weight of the crosslinking agent.
Parts by weight, UV absorber 0.3 parts by weight, light stabilizer 0.1
By weight, 0.2 parts by weight of an antioxidant and 1.0 part by weight of a silane coupling agent are mixed. The output terminal was previously turned on the back surface of the photovoltaic element, and after lamination, the output could be taken out from the terminal take-out opening previously opened in the galvalume steel plate. Thus, a solar cell module was obtained.

[0045]

Example 2 In Example 1, the glass fiber nonwoven fabric was EV
A solar cell module was produced in the same manner as in Example 1 except that two sheets were laminated just below the A sheet.

[0046]

Example 3 The thickness of the EVA sheet in Example 1 was set to 6
A solar cell module was produced in the same manner as in Example 1 except that the thickness was changed to 00 μm.

[0047]

[Example 4] In Example 1, three glass fiber nonwoven fabrics were laminated immediately above and three below each other, and the EVA sheet had a thickness of 6
A solar cell module was produced in the same manner as in Example 1 except that the thickness was changed to 00 μm.

[0048]

[Embodiment 5] In Embodiment 1, the backside insulating film is made of P.
Example 1 except that the ET film (thickness: 50 μm) was used.
A solar cell module was produced in the same manner as in.

[0049]

Example 6 The glass fiber nonwoven fabric used in Example 1 was GMC-00-080 (B) (weight per unit area: 80 g / m 2.
² , ETFE film / EVA
A solar cell module was produced in the same manner as in Example 1 except that the glass fiber non-woven fabric / cell block / EVA / insulating film / EVA / reinforcing plate were sequentially stacked so that the ETFE film was on top.

[0050]

Comparative Example 1 A solar cell module was produced in the same manner as in Example 1 except that the glass nonwoven fabric using polyvinyl acetate as the binder of the glass fiber nonwoven fabric was used in Example 1.

[0051]

Comparative Example 2 A solar cell module was manufactured in the same manner as in Example 1 except that the weight per unit area of the glass fiber nonwoven fabric was 5 g / m ² and the thickness was 25 μm.

[0052]

[Comparative Example 3] In Example 1, the glass fiber non-woven fabric was mixed with G
A solar cell module was produced in the same manner as in Example 1 except that MC-00-080 (B) (weight per unit area: 80 g / m ² , thickness: 400 μm) was used.

[0053]

Comparative Example 4 A solar cell module was produced in the same manner as in Example 1 except that the glass fiber nonwoven fabric having a binder content of 15% in the glass fiber nonwoven fabric was used.

[0054]

Comparative Example 5 Example 1 except that the surface resin film in Example 1 was changed to a stretched ETFE film thickness of 38 μm.
A solar cell module was produced in the same manner as in.

[0055]

[Comparative Example 6] The thickness of the EVA sheet in Example 1 was set to 1
A solar cell module was produced in the same manner as in Example 1 except that the thickness was changed to 000 μm.

[0056]

[Evaluation] Examples 1 to 6 and Comparative Examples 1 to 6
The following items were evaluated for each of the solar cell modules obtained in. The evaluation results obtained are summarized in Table 1.

(1) Initial appearance The initial appearance of the solar cell module was visually evaluated.
The evaluation results are shown in Table 1 according to the following evaluation criteria. That is,
◯: When there is no appearance defect, Δ: When there is some appearance defect but it is acceptable for practical use, ×: Deaeration failure,
When the appearance defect such as the curvature of the module is very large.

(2) Scratch resistance By the method as shown in FIG. 5, the most uneven surface of the module surface on the metal member is scratched with a weight of 2 pounds and 5 pounds, and the surface coating material after scratching is external. It was evaluated whether or not the insulation property with respect to can be maintained. The judgment is
The module was immersed in an electrolyte solution having a conductivity of 3000 Ω · cm, and a case where the leakage current exceeded 50 μA when a voltage of 2200 V was applied between the device and the solution was regarded as a failure. The evaluation result is 5 pounds passed: ○, 2 pounds passed:
Table 1 shows the results of Δ and failure on the basis of x.

(3) Flame retardance The solar cell module is installed on a deck inclined horizontally by 22 degrees, and 760 ± 2 is provided on the surface coating material side of the solar cell module.
A 8 ° C gas burner flame is applied for 10 minutes. A flame spread of less than 6 feet from the sample tip was accepted. The evaluation results are shown in Table 1 on the basis of ○: pass, ×: fail.
Shown in

(4) Observation of appearance under high temperature and high humidity After the solar cell module was stored at 85 ° C./85% (relative humidity) for 200 hours, the solar cell module was taken out,
The change in appearance was visually observed. The evaluation results are shown in Table 1 based on the following criteria. That is, ○: there is no change in appearance, △: there are some defects in appearance but it can be used practically, ×: defects in appearance such as poor deaeration, module bending, discoloration of the surface coating material If very large.

(5) Weather resistance A solar cell module was placed in a sunshine weatherometer, and an accelerated weather resistance test was conducted by light irradiation with a xenon lamp and a rainfall cycle.
The change in appearance after 00 hours was observed. The results are as follows: ○: When there is no change in appearance, Δ: When there are some defects in appearance but it can be used practically, ×: When there is significant peeling or discoloration of the coating material, which is clearly acceptable for practical use The standard values are shown in Table 1.

(6) Light resistance A solar cell module was placed in a super energy irradiation tester (manufactured by Suga Test Instruments Co., Ltd.) and irradiated with ultraviolet rays for 5 hours by a metal halide lamp [strength: 100 mW / cm ² @ 300].
nm-400 nm, atmosphere: Black panel temperature 70 ° C
/ Humidity 70% RH] and condensation for 1 hour [temperature 30 ° C / humidity 96% RH].
The change in appearance after 000 hours was observed. The result is ○:
When there is no change in appearance, Δ: There are some defects in appearance but it is acceptable for practical use, ×: When there is significant peeling or discoloration of the coating material and there is apparently acceptable for practical use, Table 1 Shown in.

(7) Heat resistance The solar cell module was left in an atmosphere of 90 ° C. for 3000 hours and the change in appearance was observed. The results are shown in Table 1 on the basis of the criteria of ◯ indicating no change and x indicating change such as discoloration.

As is clear from Table 1, all the solar cell modules of the Examples have practically sufficient scratch resistance,
Flame resistance, weather resistance, light resistance and heat resistance were obtained. The initial appearance was good, and there were no defects such as defective filling. Further, even after 10,000 hours of the high temperature and high humidity test and the weather resistance test, a module having an excellent appearance could be obtained without peeling that would cause a practical defect and the glass fiber nonwoven fabric was not raised. In addition, high reliability can be secured for long-term use. On the other hand, in Comparative Example 1 in which the glass woven fabric using polyvinyl acetate was used as the binder, the coating material was significantly discolored after the heat resistance test, which clearly promotes a decrease in conversion efficiency of the solar cell module. It was Further, in Comparative Example 2 in which the amount of glass fiber nonwoven fabric was small, sufficient scratch resistance could not be secured. Further, since the amount of the glass fiber non-woven fabric was small, the thickness of EVA as the filler could not be ensured, and the ETFE of EVA was slightly peeled off after the weather resistance test and the light resistance test. On the contrary, in Comparative Example 3 in which the amount of the glass fiber non-woven fabric was large, the glass fiber non-woven fabric could not be sufficiently filled, and the initial appearance had large defects. Of course, with respect to weather resistance, light resistance, heat resistance, etc., sufficient reliability cannot be obtained because deterioration of the EVA sheet is promoted due to infiltration of water.

In Comparative Example 4, since the glass fiber nonwoven fabric having a binder content of 15% was used, all of the high temperature and high humidity test, the weather resistance test, the light resistance test and the heat resistance test were conducted. In the test (1), the surface coating material was colored, which resulted in the promotion of a decrease in conversion efficiency of the solar cell module. In Comparative Example 5 in which a stretched film was used as the ETFE film on the outermost surface, cracks were confirmed in the ETFE film from the initial appearance, whereby cracks were liable to be infiltrated with water and the glass fiber was remarkably weathered at 10,000 hours. Embossing of the non-woven fabric occurred. Further, in Comparative Example 6 in which the EVA sheet as the surface filler has a large thickness of 1000 μm, the initial appearance was good, but the combustibility could not be ensured because the amount of EVA was large. Further, discoloration after the heat resistance test was also confirmed.

[0066]

[Table 1]

[0067]

According to the present invention, at least the surface of the photovoltaic element on the light incident side is coated with a transparent organic polymer resin having a fibrous inorganic compound and provided with a transparent resin film layer on the outermost surface. In the coated solar cell module, the fibrous inorganic compound is a glass fiber non-woven fabric bonded by an acrylic resin, so that scratch resistance and flame retardancy, which have been problems in the past, can be achieved at the same time, and heat resistance It is possible to obtain a highly reliable solar cell module which is excellent in weather resistance and light resistance and does not have a change in appearance such as embossing of a glass fiber nonwoven fabric even after long-term outdoor exposure.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a solar cell module of the present invention.

FIG. 2 is a schematic cross-sectional view showing the basic structure of a photovoltaic element used in the solar cell module shown in FIG.

FIG. 3 is a sectional view of a serialized module according to the present invention.

FIG. 4 is a schematic sectional view of a solar cell module according to the present invention.

FIG. 5 is a schematic diagram showing a scratch resistance test.

FIG. 6 is a schematic cross-sectional view showing an example of a conventional solar cell module.

[Explanation of symbols]

 101, 301, 401, 601 Photovoltaic element 103 Surface filler 302, 403, 602 Filler 102, 402 Glass fiber nonwoven fabric 104, 303, 404, 603 Surface resin film 105 Backside filler 106, 304, 405, 604 Insulation Film 406 Reinforcing material 201 Conductive substrate 202 Backside reflective layer 203 Semiconductor photoactive layer 204 Transparent conductive layer 205, 305a Current collecting electrode (plus side) 305b Current collecting electrode (minus side) 206a Output terminal (plus side terminal) 206b Output terminal (Negative side terminal) 207,308 Solder 208,307 Insulation tape 306 Copper tab 501 Solar cell module surface 502 Blade

Front Page Continuation (72) Inventor Ichiro Kataoka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoshi Yamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (18)

[Claims] 1. A solar cell in which at least the light-incident side surface of a photovoltaic element is covered with a covering material made of a transparent organic polymer resin having a fibrous inorganic compound and provided with a transparent resin film layer on the outermost surface. In the module, a solar cell module, wherein the fibrous inorganic compound is a glass fiber non-woven fabric bonded by an acrylic resin. 2. The solar cell module according to claim 1, wherein the fibrous inorganic compound exists as a continuous layer of two or more layers immediately above and / or immediately below the organic polymer resin. 3. The fibrous inorganic compound has a thickness of 50 μm.
To 200 μm, the solar cell module according to claim 1 or 2. 4. The solar cell module according to claim 2, wherein a weight ratio of the organic polymer resin to the fibrous inorganic compound 1 layer is 15 to 30. 5. The solar cell module according to claim 1, wherein the weight ratio of the organic polymer resin to the fibrous inorganic compound in the coating material is 4 to 12. 6. The solar cell module according to claim 1, wherein the content of the acrylic resin is 2.0% to 8.0%. 7. The solar cell module according to claim 1, wherein a content of the acrylic resin is 3.0% to 7%. 8. The solar cell module according to claim 1, wherein the fibrous inorganic compound is treated with a coupling agent. 9. The solar cell module according to claim 1, wherein the transparent resin film layer is a fluoride polymer. 10. The fluoropolymer is a tetrafluoroethylene-ethylene copolymer.
A solar cell module according to item 1. 11. The wetting index of the tetrafluoroethylene-ethylene copolymer film layer on the photovoltaic device side is 40 d.
The solar cell module according to claim 10, wherein the solar cell module is yne to 45 dyne. 12. The ASTM D of the transparent resin film
The solar cell module according to any one of claims 1 to 11, wherein the tensile breaking elongation in the -882 test method is 200% to 800% in both the longitudinal direction and the lateral direction. 13. The solar cell module according to claim 1, wherein at least one of the transparent organic polymer resins is a thermoplastic polyolefin resin. 14. The solar cell module according to claim 13, wherein the thermoplastic polyolefin resin is an ethylene-vinyl acetate copolymer (EVA). 15. The transparent organic polymer resin is treated with a coupling agent, according to any one of claims 1 to 14.
The solar cell module according to any one of 1. 16. The transparent organic polymer resin has a thickness of 20.
The thickness is 0 μm to 800 μm.
16. The solar cell module according to any one of 1 to 15. 17. The solar cell module according to claim 1, wherein the solar cell module is manufactured by laminating with a single vacuum exhaust system. 18. The solar cell module according to claim 1, wherein the solar cell module is manufactured by laminating and stacking the photovoltaic element with the light receiving surface side facing upward. Battery module.