JP2005347721A - Filling material layer for solar cell module and solar cell module using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filling material layer for a solar cell module that is capable of preventing the incursion of water if the layer is determined to be a solar cell module and never adversely affects a solar cell element, an electrode or the like if a transparent front substrate or a backside protective sheet is broken and so on after the layer has been used for a long period of time or even if the layer is used under a high humidity condition and so on. <P>SOLUTION: The filling material layer for a solar cell module is used in the solar cell module, wherein water vapor permeability per thickness of the solar cell module filling layer of 100 μm is 0.9 to 9 g/m<SP>2</SP>day. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filler layer for a solar cell module excellent in water vapor barrier properties, and a solar cell module using the same.

In recent years, solar cells as clean energy sources have attracted attention due to increasing awareness of environmental problems, and solar cell modules having various forms have been developed and proposed.
In general, the above solar cell module is laminated in the order of, for example, a transparent front substrate, a filler layer, a solar cell element as a photovoltaic element, a filler layer, and a back surface protective sheet, and then vacuum-suck them. It is manufactured using the lamination method etc. which are thermocompression bonded.

Currently, ethylene-vinyl acetate copolymer resin having a thickness of 100 μm to 1500 μm is the most common material constituting the filler layer for solar cell modules from the viewpoint of processability, workability, manufacturing cost, etc. It is used as a typical one.
However, when producing a solar cell module using a filler layer made of an ethylene-vinyl acetate copolymer resin, the ethylene-vinyl acetate copolymer resin undergoes thermal decomposition or the like due to conditions such as thermocompression bonding, There is a problem that acetic acid gas and the like are generated, which not only worsen the working environment and the like, but also adversely affect the solar cell elements, electrodes, and the like, thereby causing deterioration and reduction in power generation efficiency.

Furthermore, the filler layer made of the ethylene-vinyl acetate copolymer resin has poor water vapor permeability, and when used in a high humidity environment, moisture reaches the solar cell element. However, it may adversely affect the solar cell element, the electrode, etc., and may cause problems such as deterioration and reduction in power generation efficiency.
On the other hand, in order to solve the above-described problem, a technique for separately forming a water vapor barrier layer on the back surface protection sheet has been disclosed (Patent Document 1). However, this technique requires a process for forming the water vapor barrier layer, which takes time when forming the solar cell module, and may cause a problem in terms of manufacturing cost.

JP-A-6-61518

  Therefore, when the present invention is a solar cell module, it is possible to prevent moisture from entering, and when the transparent front substrate or the back surface protective sheet is damaged after long-term use, or used under high humidity conditions. Even if it is a case etc., it aims at providing the filler layer for solar cell modules which does not have a bad influence on a solar cell element, an electrode, etc.

In the present invention, in order to achieve the above object, the solar cell module filler layer used in the solar cell module, the water vapor permeability per 100 μm of the thickness of the solar cell module filler layer Is 0.9-9 g / m < ² > * day, The solar cell module filler layer is provided.
If the filler layer for the solar cell module as described above can sufficiently prevent moisture from entering, even if it is used under high humidity conditions, the moisture can reach the solar cell element. Intrusion can be prevented, and the solar cell element, the electrode, and the like can be adversely affected and power generation efficiency can be prevented from decreasing. In particular, after long-term use, when the transparent front substrate, the back protective sheet is broken, damaged, deteriorated, etc., the filler layer may be exposed to the outside environment. In the present invention, since the filler layer itself has good water vapor permeability, deterioration of elements and electrodes can be suppressed.
Here, it is preferable that the thickness of the said filler layer for solar cell modules is 50-2000 micrometers.

In the present invention, the filler layer for a solar cell module further contains a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polymerization polyethylene, and the gel fraction is 30% or less. It is preferable.
Since the filler layer for solar cell modules as described above has a silane-modified resin in addition to the above-described good water vapor permeability, it is in close contact with a transparent front substrate such as glass and a back surface protective sheet. Since the main chain is made of polyethylene, no harmful gas is generated and the working environment is not deteriorated. In addition, when used in a solar cell module, the gel fraction of the solar cell module filler layer is in the above range, so that it can be sealed in a short time, and further there is an advantage that heat treatment or the like is unnecessary. .

In this invention, it is preferable that the said filler layer for solar cell modules further has polyethylene for addition. Since the cost of the silane-modified resin is high, it is preferable that the filler layer for the solar cell module contains the additive polyethylene.
In the present invention, the polyethylene for polymerization and the polyethylene for addition further comprise low density polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, very low density polyethylene, and linear low density polyethylene. It is preferably at least one polyethylene selected from the group.

  Furthermore, it is preferable that 8 ppm to 3500 ppm of Si (silicon) is contained in the filler layer for solar cell module as the amount of polymerized Si. This is because by having the amount of polymerized Si within this range, the adhesion to the solar cell element and the transparent front substrate can be improved.

  Furthermore, in this invention, it is preferable that the silanol condensation catalyst is not substantially contained in the said filler layer for solar cell modules. In the present invention, since the gel fraction in the solar cell module filler layer is preferably a predetermined value or less, the resin composition using the ethylenically unsaturated silane compound is used for water crosslinking and the like. This is because the desired gel fraction cannot be obtained if a silanol condensation catalyst generally blended in is contained.

  The present invention also provides a solar cell module comprising the solar cell module filler layer. The solar cell module having the solar cell module filler layer according to the present invention has the advantages of the solar cell module filler layer as described above and is advantageous in terms of cost.

  The filler layer for the solar cell module of the present invention has moisture even when used under high humidity conditions, or when the transparent front substrate and the back protective sheet are damaged, damaged or deteriorated after long-term use. Intrusion to the solar cell element can be prevented, the solar cell element, the electrode and the like are adversely affected, and power generation efficiency can be prevented from being lowered.

  The present invention includes a solar cell module filler layer and a solar cell module using the same. Hereinafter, the filler layer for solar cell modules and the solar cell module using the same will be described. In the present invention, a sheet means any of a sheet-like material or a film-like material, and a film means any case of a film-like material or a sheet-like material. is there.

A. First, the filler layer for solar cell modules of the present invention will be described. The solar cell module filler layer of the present invention is a solar cell module filler layer used in the solar cell module, and has a water vapor transmission rate per 100 μm in thickness of the solar cell module filler layer. It is 0.9 to 9 g / m ² · day. In the present invention, because the solar cell module filler layer as described above is used, when used for a long time in a high-humidity environment, or after long-term use, the transparent front substrate, the back protective sheet is broken, damaged, When the filler layer is exposed to the outside environment due to deterioration, etc., moisture can be prevented from reaching the solar cell element, and adverse effects on the solar cell element and electrodes can be prevented. Therefore, it is possible to prevent a decrease in power generation efficiency over a long period of time even in various usage environments.

Here, the value of the water vapor transmission rate per 100 μm thickness of the solar cell module filler layer in the present invention is calculated by utilizing the property that the water vapor transmission rate is inversely proportional to the thickness of the resin film. Specifically, the thickness of the solar cell module filler layer is d (μm), the water vapor transmission rate is X (g / m ² · day), and the water vapor transmission rate per 100 μm is x (g / g / m). m ² · day)
x = Xd / 100
Use the value obtained in.

  The water vapor transmission rate in the present invention is a value measured by a water vapor transmission rate measuring device (PERMATRAN: model name) manufactured by MOCON under the conditions of a measurement temperature of 37.8 ° C. and a humidity of 90% RH. .

Moreover, it is preferable that the filler layer for solar cell modules of this invention has the said water vapor permeability, and the function as a normal filler layer for solar cell modules is favorable.
Specifically, the adhesiveness with the transparent front substrate has a predetermined value, and was measured based on a predetermined rule of the solar cell module using the solar cell module filler layer of the present invention. It is preferable that the output maintenance rate of the photovoltaic power before and after the test is 80% or more.
As the adhesion to the transparent front substrate, the peel strength with respect to the transparent front substrate measured in a 180 ° peel test in a 25 ° C. atmosphere of the solar cell module filler layer is in the range of 1 N / 15 mm width to 150 N / 15 mm width. In particular, it is preferably in the range of 3 N / 15 mm width to 150 N / 15 mm width, and 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

  Moreover, in the solar cell module using the solar cell module filler layer of the present invention, the output retention rate of the photovoltaic power before and after the test measured based on a predetermined rule is in the range of 80% to 100%. It is preferable that it is within a range of 90% to 100%, particularly 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.
As a material for the solar cell module filler layer that satisfies the above-described conditions, the solar cell module filler contains a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polyethylene for polymerization. When a layer is used for a solar cell module, a material having a gel fraction of 30% or less can be given as an example of a suitable material.
Hereinafter, the suitable material of such a filler layer for solar cell modules is demonstrated.

1. Silane Modified Resin The silane modified resin used in the present invention is obtained by polymerizing an ethylenically unsaturated silane compound and polymerization polyethylene. Such a silane-modified resin is obtained by mixing an ethylenically unsaturated silane compound, a polymerization polyethylene and a radical generator, melting and stirring at a high temperature, and graft-polymerizing the ethylenically unsaturated silane compound onto the polymerization polyethylene. be able to.

  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 as long as it is graft-polymerized with the above-described polyethylene for polymerization. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyl Triisopropoxysilane, vinyltributoxysilane, vinyltripentyloxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltrimethylenedioxysilane, vinyltriethylenedioxysilane, vinylpropionyloxysilane, vinyltriacetoxysilane , And at least one selected from the group consisting of vinyltricarboxysilane can be used. In the present invention, among these, vinyltrimethoxysilane is preferably used.

  The amount of the ethylenically unsaturated silane compound contained in the solar cell module filler layer in the present invention is preferably 10 ppm or more, more preferably 20 ppm or more. The solar cell module filler layer has the ethylenically unsaturated silane compound polymerized with the polymerizing polyethylene, so that the material used for the transparent front substrate and back sheet for solar cell modules described later, such as glass, etc. This achieves good adhesion. Therefore, when it is less than the range mentioned above, adhesiveness with glass etc. is insufficient. Further, the upper limit of the amount of the ethylenically unsaturated silane compound is preferably 4000 ppm or less, and more preferably 3000 ppm or less. The upper limit is not limited in terms of adhesion to glass or the like, but if it exceeds the above range, the adhesion to glass or the like does not change and the cost increases.

  The silane-modified resin is preferably contained in the solar cell module filler layer in the range of 1 to 80% by weight, more preferably in the range of 5 to 70% by weight. Similarly, in this case, the silane-modified resin has an ethylenically unsaturated silane compound polymerized with the polymerization polyethylene, thereby providing adhesion to glass or the like. Therefore, the said filler layer for solar cell modules has high adhesiveness with glass etc. by having the above silane modified resins. Therefore, the above-mentioned range is preferably used from the viewpoint of adhesion to glass or the like and cost.

Further, the silane modified resin preferably has a melt mass flow rate at 190 ° C. of 0.5 to 10 g / 10 minutes, more preferably 1 to 8 g / 10 minutes. It is because it is excellent in the moldability of the filler layer for solar cell modules, adhesiveness with the transparent front substrate and the back surface protective sheet, and the like.
Moreover, it is preferable that melting | fusing point of the said silane modified resin is 110 degrees C or less. When manufacturing a solar cell module using the solar cell module filler layer, the above range is preferable in terms of workability and the like.

  Examples of the radical generator to be added to the silane-modified resin include hydroperoxides such as diisopropylbenzene hydroperoxide and 2,5-dimethyl-2,5-di (hydroperoxy) hexane; di-t-butyl Peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-peroxy) ) Dialkyl peroxides such as hexyne-3; bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, etc. Diacyl peroxides; t-butyl peroxyacetate Over DOO, t- butyl peroxy-2-ethylhexanoate, t- butyl peroxypivalate, t- butyl peroxy octoate. t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, di-t-butyl peroxyphthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2, Peroxyesters such as 5-di (benzoylperoxy) hexyne-3; organic peroxides such as methyl peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; or azobisisobutyronitrile and azobis (2 , 4-dimethylvaleronitrile) and the like.

The amount of the radical generator used is preferably 0.001% by weight or more in the silane-modified resin. This is because radical polymerization between the ethylenically unsaturated silane compound and the polymerization polyethylene hardly occurs when the amount is less than the above range.
In addition, the silane modified resin used for this invention can be used also for a laminated glass use. Laminated glass is produced by thermocompression bonding between a glass and a glass with a flexible and tough resin or the like. From the viewpoint of adhesion to glass, the silane-modified resin may be used. it can.

2. Additive Polyethylene In the present invention, the solar cell module filler layer preferably includes the silane-modified resin and the additive polyethylene. Examples of the polyethylene for addition include the same as those described in the above-mentioned “1. Silane modified resin”. In the present invention, the additive polyethylene is particularly preferably the same resin as the polymerization polyethylene. Since the cost of the silane-modified resin is high, the silane-modified resin and the additive polyethylene are mixed to form the solar cell module filler layer, rather than forming the solar cell module filler layer only with the silane-modified resin. This is because it is advantageous in terms of cost.
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 silane modified resin.
When using 2 or more types of the said silane modified resin, it is preferable that content of the polyethylene for addition becomes the said range with respect to the total amount of 100 weight part.

The polyethylene for addition preferably has a melt mass flow rate at 190 ° C. of 0.5 to 10 g / 10 min, more preferably 1 to 8 g / 10 min. It is because it is excellent in the moldability of the filler layer for solar cell modules.
Furthermore, the melting point of the additive polyethylene is preferably 130 ° C. or lower. The above range is preferable in terms of workability and the like during the production of the solar cell module using the solar cell module filler layer.
The melting point is measured by differential scanning calorimetry (DSC) in accordance with the plastic transition temperature measurement method (JISK7121). In this case, when two or more melting points exist, the higher temperature is defined as the melting point.

3. Additives In the present invention, additives such as a light stabilizer, an ultraviolet absorber, and a heat stabilizer can be used as necessary. The solar cell module filler layer of the present invention has a silane-modified resin as described above, and a mechanical stabilizer and an adhesive strength that are stable over a long period of time by adding a light stabilizer, an ultraviolet absorber, and a thermal stabilizer to this. , Yellowing prevention, crack prevention, and excellent processability can be obtained.
The light stabilizer captures the active species at the start of photodegradation in the polymer used in the polymerization polyethylene and the additive polyethylene and prevents photooxidation. Specifically, at least one selected from the group consisting of a hindered amine compound, a hindered piperidine compound, and the like can be used.

  The ultraviolet absorber absorbs harmful ultraviolet rays in sunlight, converts them into innocuous heat energy in the molecule, and initiates photodegradation activity in the polymer used for the polymerization polyethylene and the additive polyethylene. It prevents the species from being excited. Specifically, benzophenone-based, benzotriazole-based, salicylate-based, acrylonitrile-based, metal complex salt-based, hindered amine-based, ultrafine titanium oxide (particle diameter: 0.01 μm to 0.06 μm) or ultrafine zinc oxide ( At least one type selected from the group consisting of inorganic ultraviolet absorbers (particle diameter: 0.01 μm to 0.04 μm) can be used.

  Examples of the heat stabilizer include tris (2,4-di-tert-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorus Acid, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite, and bis (2,4-di-tert-butylphenyl) penta Phosphorus heat stabilizers such as erythritol diphosphite; and lactone heat stabilizers such as a reaction product of 8-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene Can do. Moreover, these can also use 1 type (s) or 2 or more types. Among these, it is preferable to use a phosphorus heat stabilizer and a lactone heat stabilizer in combination.

The content of the light stabilizer, ultraviolet absorber, heat stabilizer and the like varies depending on the particle shape, density, etc., but is preferably in the range of 0.01 to 5% by weight in the solar cell module filler layer. .
Moreover, when the said filler layer for solar cell modules is used for a solar cell module so that it may mention later, it is preferable that a gel fraction is low. For this reason, it is not necessary for the silane-modified resin to form a crosslinked structure. Therefore, a crosslinking agent or a catalyst for promoting the condensation reaction of silanol groups is not particularly required.

  Specifically, it is preferable that a silanol condensation catalyst that promotes a dehydration condensation reaction between silanols of silicone such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctate, and dioctyltin dilaurate is substantially not contained. Here, “substantially not contained” refers to a case where the amount is 0.05 parts by weight or less with respect to 100 parts by weight of the resin constituting the filler layer for a solar cell module.

4). Solar Cell Module Filler Layer The film thickness of the solar cell module filler layer of the present invention is preferably in the range of 50 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.

Furthermore, in the present invention, Si (silicon) is contained in the solar cell module filler 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. It is preferable. This is because when the amount of polymerized Si is included within this range, it is possible to maintain good adhesion with the transparent front substrate and the solar cell element, and it can be said that the above range is preferable from the viewpoint of cost.
In the present invention, the amount of polymerized Si is measured by heating only the filler layer for the solar cell module, burning it, and ashing to convert the polymerized Si to SiO ₂ , so that the ash is alkali-melted. Then, a method is used in which the volume of polymerized Si is quantified by an ICP emission analysis (high-frequency plasma emission analyzer: ICPS8100, manufactured by Shimadzu Corporation) after dissolution in pure water.

Furthermore, the resin constituting the solar cell module filler layer preferably has a melt mass flow rate at 190 ° C. of 0.5 to 10 g / 10 min, more preferably 1 to 8 g / 10 min. . It is because it is excellent in the moldability of the filler layer for solar cell modules, adhesiveness with the transparent front substrate and the back surface protective sheet, and the like.
Moreover, it is preferable that melting | fusing point of resin which comprises the said filler layer for solar cell modules is 130 degrees C or less. When manufacturing a solar cell module using the solar cell module filler layer, the above range is preferable in terms of workability and the like. In addition, since the measuring method of melting | fusing point is the same as that of what was mentioned above, description here is abbreviate | omitted.

  Moreover, when the filler layer for solar cell modules of this invention is used for a solar cell module, it is preferable that a gel fraction is 30% or less, especially 10% or less, especially 0%. Since the silane-modified resin used in the present invention does not form a crosslinked structure in this way, it can be sealed in a short time, and post-treatment such as heat treatment is unnecessary. Moreover, when a gel fraction exceeds the said range, the workability at the time of solar cell module manufacture will fall, and the improvement of adhesiveness with a transparent front substrate and a back surface protection sheet will not be recognized.

The gel fraction when the solar cell module filler layer is used for the solar cell module is, for example, a transparent front substrate, a solar cell module filler layer, a solar cell element, a solar cell module filler layer, And a back surface protective sheet are sequentially laminated, and then the solar cell module is manufactured using each layer as an integrally molded body by using a normal molding method such as a lamination method in which these are integrated and then vacuum sucked and thermocompression bonded. It refers to the gel fraction of the solar cell module filler layer.
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 10 hours of continuous extraction, the whole wire mesh and the sample are taken out, weighed after the drying treatment, the weight before and after extraction is compared, the weight% of the remaining insoluble matter is measured, and this is used as the gel fraction.

5). Next, the manufacturing method of the filler layer for solar cell modules of this invention is demonstrated.
First, the preparation method of the silane modified resin used for this invention is demonstrated. The silane-modified resin can be obtained by heat-melt mixing a mixture of an ethylenically unsaturated silane compound, a polymerization polyethylene and a radical generator, and graft-polymerizing the ethylenically unsaturated silane compound onto the polymerization polyethylene. .

Although there is no particular limitation on the method of heating and melting and mixing these mixtures, the additive is preferably a method in which a master batch in which the additives are previously kneaded and contained in the resin is mixed with the main raw material and extruded and melted. The heating temperature is preferably 300 ° C. or lower, and more preferably 270 ° C. or lower. The silane-modified resin is preferably melt-mixed in the above range because the silanol group portion is easily cross-linked and gelled by heating.
Next, the formation method of the filler layer for solar cell modules of this invention is demonstrated. After the silane-modified resin is heated and melted and mixed as described above, the obtained silane-modified resin can be pelletized, and heated and melted again to be extruded, but the silane-modified resin and the silane-modified resin are placed in the hopper of the extruder. It is also possible to mix and add the additive polyethylene and heat and melt it in a cylinder, and the latter is superior in terms of cost.

After the above-described resin is heated and melted, it can be formed into a sheet having a thickness of 50 to 2000 μm by an existing method such as T-die or inflation to obtain a filler layer for a solar cell module.
The heating temperature at the time of heating and melting again is preferably 300 ° C. or lower, more preferably 270 ° C. or lower. As described above, since the silanol group portion of the silane-modified resin is easily cross-linked and gelled by heating, it is desirable to heat and melt the resin within the above range and to extrude.

B. Next, the solar cell module of the present invention will be described. The solar cell module of the present invention has the filler layer for a solar cell module of the present invention described above. FIG. 1 is a schematic cross-sectional view showing an example of a solar cell module manufactured using a filler layer for a solar cell module. As shown in FIG. 1, a transparent front substrate 1, a solar cell module filler layer 2, a solar cell element 3 as a photovoltaic element, a solar cell module filler layer 2, a back surface protection sheet 4, etc. Then, the solar cell module T can be manufactured using each layer as an integrally formed body by using a normal forming method such as a lamination method in which these are integrated and then vacuum sucked and thermocompression bonded.

  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. .

In the present invention, the solar cell module filler layer may be provided between the transparent front substrate and the solar cell element, or between the transparent front substrate and the solar cell element, and the back surface protective sheet and the solar cell. You may provide between elements.
Moreover, in the said solar cell module, it can laminate | stack by adding another layer arbitrarily for purposes, such as absorptivity of sunlight, reinforcement, others.

As the transparent front substrate used in the solar cell module of the present invention, glass, a fluorine resin sheet, a transparent composite sheet obtained by laminating and laminating a weather resistant film and a barrier film, and the like can be used.
Moreover, as a back surface protection sheet used for the solar cell module of the present invention, a metal such as aluminum, a fluorine resin sheet, a composite sheet obtained by laminating and laminating a weather resistant film and a barrier film, or the like can be used.
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.

The following examples further illustrate the invention.
[Example 1]
(1) Preparation of silane modified resin Density 0.898 g / cm ³ , melt flow rate at 190 ° C. (hereinafter referred to as MFR) 2 g / 10 min linear low density polyethylene (hereinafter referred to as LLDPE) 98 weight 2 parts by weight of vinyltrimethoxysilane and 0.1 part by weight of dicumyl peroxide as a radical generator were mixed with each part, and heated and melted and stirred at 200 ° C. to obtain a silane-modified resin.

(2) Formation of filler layer for solar cell module 10 parts by weight of the above silane-modified resin, 90 parts by weight of LLDPE having a density of 0.898 g / cm ³ and MFR of 2 g / 10 min at 190 ° C., a light stabilizer prepared separately, 5 parts by weight of a master batch containing an ultraviolet absorber and a heat stabilizer (based on 100 parts by weight of a linear low density polyethylene, 3.75 parts by weight of a hindered amine light stabilizer, 3.75 parts by weight of a benzotriazole ultraviolet absorber, Phosphorus heat stabilizer 0.5 parts by weight is mixed, melted, processed and pelletized) and mixed into a φ25 mm extruder, a hopper of a film molding machine having a 300 mm width T-die, an extrusion temperature of 230 ° C., A sheet having a thickness of 250 μm was formed at a take-up speed of 4.8 m / min. The above film formation could be carried out without hindrance. Through these series of operations, a filler layer for a solar cell module was obtained.
(3) Production of solar cell module Using the above solar cell module filler layer, a glass plate having a thickness of 3 mm, a solar cell module filler layer having a thickness of 250 μm prepared in the above (2), and crystalline silicon Solar cell element, filler layer for solar cell module having a thickness of 250 μm, a polyvinyl fluoride resin sheet (PVF) having a thickness of 38 μm, an aluminum foil having a thickness of 30 μm, and a polyvinyl fluoride resin having a thickness of 38 μm A laminated sheet composed of a sheet (PVF) is laminated via an acrylic resin adhesive layer, the solar cell element surface is directed upward, and a vacuum laminator for producing a solar cell module at 150 ° C. for 14 minutes. The solar cell module was obtained by pressure bonding.

[Examples 2 to 6]
(1) Preparation of silane-modified resin In the same manner as in Example 1, a silane-modified resin was obtained.
(2) Formation of Filler Layer for Solar Cell Module In Example 2, the take-up speed was 2.9 m / min, in Example 3, the take-up speed was 2.0 m / min, and in Example 4, the take-up speed was taken up. The speed is 1.5 m / min, in Example 5, the take-up speed is 1.2 m / min, and in Example 6, except that the sheet is formed at a take-up speed of 1.0 m / min. Similarly, the film could be formed without any trouble. At this time, in Example 2, the thickness is 400 μm, in Example 3, the thickness is 600 μm, in Example 4, the thickness is 800 μm, in Example 5, the thickness is 1000 μm, and in Example 6, the thickness is 1200 μm. A filler layer for a solar cell module was obtained.
(3) Manufacture of solar cell module In Example 2, as in Example 1, in Examples 3 to 6, Example 1 was used except that it was pressure-bonded at 150 ° C for 18 minutes with a vacuum laminator for manufacturing a solar cell module. The solar cell module was obtained by producing similarly.

[Examples 7 and 8]
(1) Preparation of silane-modified resin In the same manner as in Example 1, a silane-modified resin was obtained.
(2) Formation of solar cell module filler layer In Example 7, 40 parts by weight of the silane-modified resin, 60 parts by weight of LLDPE having an MFR of 2.0 g / 10 min and a density of 0.898 g / cm ³ , In Example 8, except that the silane-modified resin was changed to 100 parts by weight, the film could be formed without any trouble in the same manner as in Example 1, and a solar cell module filler layer having a thickness of 400 μm was obtained. .
(3) Production of solar cell module A solar cell module was obtained in the same manner as in Example 1.

[Example 9]
(1) Preparation of silane-modified resin In the same manner as in Example 1, a silane-modified resin was obtained.
(2) Formation of solar cell module filler layer A solar cell module filler layer was obtained in the same manner as in Example 8.
(3) Production of solar cell module A solar cell module was obtained by producing in the same manner as in Example 1 except that the vacuum laminator for producing the solar cell module was pressure-bonded at 180 ° C for 30 minutes.

[Example 10]
(1) Preparation of silane-modified resin A silane-modified resin was obtained in the same manner as in Example 1 except that LFRPE of MFR2.2 at a density of 0.865 g / cm ³ and 190 ° C was used.
(2) Formation of filler layer for solar cell module 40 parts by weight of the silane-modified resin, 60 parts by weight of LLDPE of MFR2.2 at a density of 0.865 g / cm ³ and 190 ° C., and a light stabilizer prepared separately. 5 parts by weight of a master batch containing an ultraviolet absorber and a heat stabilizer (based on 100 parts by weight of a linear low density polyethylene, 3.75 parts by weight of a hindered amine light stabilizer, 3.75 parts by weight of a benzotriazole ultraviolet absorber, Phosphorus heat stabilizer 0.5 parts by weight is mixed, melted, processed and pelletized) and mixed into a φ25 mm extruder, a hopper of a film molding machine having a 300 mm width T-die, an extrusion temperature of 230 ° C., A sheet having a thickness of 400 μm was formed at a take-up speed of 2.9 m / min. The above film formation could be carried out without hindrance. Through these series of operations, a filler layer for a solar cell module was obtained.
(3) Production of Solar Cell Module A solar cell module was obtained in the same manner as in Example 1.

[Example 11]
(1) Preparation of silane modified resin Density 0.930 g / cm ³ , MFR at 190 ° C. of LLDPE of 97 parts by weight of 97 parts by weight of LLDPE, 3 parts by weight of vinyltrimethoxysilane, dicumylpar as a radical generator 0.15 parts by weight of oxide was mixed and heated, melted and stirred at 200 ° C. to obtain a silane-modified resin.
(2) Formation of Filler Layer for Solar Cell Module 40 parts by weight of the above silane-modified resin, 60 parts by weight of LLDPE having a density of 0.930 g / cm ³ and an MFR at 190 ° C. of 3.7 g / 10 min. 5 parts by weight of a master batch containing a stabilizer, an ultraviolet absorber, and a heat stabilizer (3.75 parts by weight of a hindered amine light stabilizer and 100 parts by weight of a linear low density polyethylene, 3. a benzotriazole ultraviolet absorber; 75 parts by weight and 0.5 parts by weight of a phosphorus-based heat stabilizer are mixed, melted, processed, and pelletized), and are put into a hopper of a film forming machine having a φ25 mm extruder and a 300 mm wide T-die and extruded. A sheet having a thickness of 400 μm was formed at a temperature of 230 ° C. and a take-up speed of 2.9 m / min. The above film formation could be carried out without hindrance. Through these series of operations, a filler layer for a solar cell module was obtained.
(3) Production of Solar Cell Module A solar cell module was obtained in the same manner as in Example 1.

[Example 12]
(1) Preparation of silane-modified resin Density 0.930 g / cm ³ , MFR at 190 ° C. of LLDPE 97 parts by weight is 3 parts by weight of vinyltrimethoxysilane, and dicumylpar as a radical generator. 0.15 parts by weight of oxide was mixed and heated, melted and stirred at 200 ° C. to obtain a silane-modified resin.
(2) Formation of Filler Layer for Solar Cell Module 40 parts by weight of the above silane-modified resin, 60 parts by weight of LLDPE having a density of 0.930 g / cm ³ and an MFR at 190 ° C. of 3.7 g / 10 min. 5 parts by weight of a master batch containing a stabilizer, an ultraviolet absorber, and a heat stabilizer (3.75 parts by weight of a hindered amine light stabilizer and 100 parts by weight of a linear low density polyethylene, 3. a benzotriazole ultraviolet absorber; 75 parts by weight and 0.5 parts by weight of a phosphorus-based heat stabilizer are mixed, melted, processed, and pelletized), and are put into a hopper of a film forming machine having a φ25 mm extruder and a 300 mm wide T-die and extruded. A sheet having a thickness of 400 μm was formed at a temperature of 230 ° C. and a take-up speed of 2.9 m / min. The above film formation could be carried out without hindrance. Through these series of operations, a filler layer for a solar cell module was obtained.
(3) Production of Solar Cell Module A solar cell module was obtained in the same manner as in Example 1.

[Comparative Example 1]
100 parts by weight of an ethylene-vinyl acetate copolymer (28 parts by weight of vinyl acetate) having a density of 0.942 g / cm ³ and an MFR at 190 ° C. of 15 g / 10 minutes, 2 parts by weight of vinyltrimethoxysilane, radicals As a generator, 0.2 part by weight of tertiary butyl peroxide was mixed, and heated and melted and stirred at 200 ° C. to obtain a silane-modified ethylene-vinyl acetate copolymer.
100 parts by weight of this silane-modified ethylene-vinyl acetate copolymer and 5 parts by weight of a master batch containing a crosslinking agent, a light stabilizer, a UV absorber, and a heat stabilizer separately prepared (ethylene-vinyl acetate copolymer 100) 2.0 parts by weight of tertiary butyl peroxide, 3.75 parts by weight of a hindered amine light stabilizer, 3.75 parts by weight of a benzotriazole ultraviolet absorber, and 0.5 parts by weight of a phosphorous heat stabilizer with respect to parts by weight. Mixed, melted, processed, and pelletized), and put into a hopper of a φ25 mm extruder and a film molding machine having a 300-mm-wide T-die, and an extrusion temperature of 100 ° C. and a take-up speed of 2.9 m / min. A 400 μm sheet was formed. The above film formation could be carried out without hindrance. Through these series of operations, a filler layer for a solar cell module was obtained.
About preparation of a solar cell module, after crimping | bonding by 150 degreeC 14 minutes with the vacuum laminator for solar cell module manufacture, the solar cell module was obtained by heating in 150 degreeC 15 minutes.

[Comparative Example 2]
In Comparative Example 1, a solar cell module filler layer and a solar cell module were obtained in the same manner as in Comparative Example 1 except that the crosslinking agent was not added to the master batch.

[Evaluation]
The water vapor transmission rate (before and after the deterioration test) and the gel fraction of Examples 1 to 12 and Comparative Examples 1 and 2 were measured. The results are summarized in Table 1. The test method is as follows.
(Water vapor transmission rate)
The obtained solar cell module filler layer sheet was sandwiched between front and back ethylene tetrafluoroethylene copolymer films, and the film was peeled off after thermocompression bonding in a vacuum laminator for manufacturing solar cell modules under each module process condition. Then, only the heated filler layer for solar cell module was used for the measurement.
Moreover, after storing only the said filler layer for solar cell modules on 85 degreeC and 85% RH conditions for 1000 hours, the high-temperature and high-humidity storage stability of water vapor permeability was evaluated by measuring water vapor permeability.
(Gel fraction)
It measured using the method demonstrated in the column of the said "A. Solar cell module filler layer".

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

Explanation of symbols

2 ... Solar cell module filler layer T ... Solar cell module

Claims (8)

A solar cell module filler layer used in a solar cell module,
The solar cell module filler layer, wherein the solar cell module filler layer has a water vapor transmission rate of 0.9 to 9 g / m ² · day per 100 μm in thickness. The thickness of the said filler layer for solar cell modules is 50-2000 micrometers, The filler layer for solar cell modules of Claim 1 characterized by the above-mentioned. The solar cell module filler layer contains a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polymerization polyethylene, and has a gel fraction of 30% or less. The filler layer for solar cell modules according to claim 1 or 2. 4. The solar cell module filler layer according to claim 3, wherein the solar cell module filler layer further includes polyethylene for addition. The polymerization polyethylene and the additive polyethylene are at least selected from the group consisting of low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, ultra-low-density polyethylene, and linear low-density polyethylene. The filler layer for a solar cell module according to claim 3 or 4, wherein the filler layer is one polyethylene. 6. The solar cell module filler layer according to claim 3, wherein Si (silicon) is contained in an amount of 8 ppm to 3500 ppm as the amount of polymerized Si. Filler layer for solar cell modules. The solar cell module filler according to any one of claims 3 to 6, wherein a silanol condensation catalyst is substantially not contained in the solar cell module filler layer. layer. A solar cell module comprising the solar cell module filler layer according to any one of claims 1 to 7.

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