JP2006245503A - Filler for solar cell module, solar cell module employing same, and method of manufacturing filler for solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To mainly provide a filler for solar cell module in which filler resin can be suppressed from getting cloudy when a hot-spot phenomenon occurs. <P>SOLUTION: The present invention provides a filler for solar cell module containing filler resin which contains silane modified resin resulting from polymerizing an ethylene unsaturated silane compound and polyethylene for polymerization, and a nucleus agent distributed in the filler resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a solar cell module filler used in a solar cell module.

In recent years, solar cells as a clean energy source have attracted attention due to the growing awareness of environmental issues.
Solar cell elements are often manufactured using a single crystal silicon substrate or a polycrystalline silicon substrate. For this reason, the solar cell element is vulnerable to physical impact, and it is necessary to protect it from rain when the solar cell is installed outdoors. Moreover, since the electrical output generated by one solar cell element is small, it is necessary to connect a plurality of solar cell elements in series and parallel so that a practical electrical output can be taken out. For this reason, a solar cell module is usually manufactured by connecting a plurality of solar cell elements and enclosing them with a transparent substrate and a filler. In general, a solar cell module is manufactured by using a lamination method or the like in which a transparent front substrate, a filler, a solar cell element, a filler, a back surface protection sheet, and the like are sequentially laminated, and these are vacuum-sucked and thermocompression bonded.

  Currently, as a filler, ethylene-vinyl acetate copolymer resin (EVA) having a thickness of 100 μm to 1500 μm is most commonly used from the viewpoints of processability, workability, manufacturing cost, etc. ing. However, the filler made of ethylene-vinyl acetate copolymer resin has a problem that the adhesive strength with the solar cell element is not always sufficient, and peeling occurs when used for a long time. Therefore, as a method of imparting adhesiveness to the filler, a method of polymerizing a silane compound on a resin has been proposed (see, for example, Patent Document 1 and Patent Document 2).

  In a solar cell module installed outdoors, when a certain solar cell element is in the shadow of a plurality of solar cell elements of a solar cell module that is generating power, The battery element becomes a resistance. At this time, a potential difference of the product of the resistance value and the flowing current is generated in both electrodes of the solar cell element. That is, a reverse bias voltage is applied to the solar cell element, and the solar cell element generates heat. Such a phenomenon is called a hot spot.

And when a hot spot phenomenon generate | occur | produces and the temperature of a solar cell element rises, the temperature of a filler will also rise in connection with this. When the outside air temperature decreases, the temperature of the solar cell module, that is, the temperature of the solar cell element and the filler decreases, but the outside temperature gradually decreases, so the filler whose temperature has increased due to the occurrence of the hot spot phenomenon is gradually cooled. That is, it is gradually cooled.
When a polymer resin obtained by polymerizing a silane compound with the above-described resin is used as a filler, crystals slowly grow in the filler when it is slowly cooled, and part of the filler becomes cloudy and the appearance is remarkably increased. Damaged.

  As a method of suppressing the temperature rise of the solar cell module when the hot spot phenomenon occurs, for example, a film having a high heat emissivity with an uneven surface on the back side of the solar cell module or around the solar cell module It has been proposed to provide a ventilation opening in the module frame (see, for example, Patent Document 3). In addition, by incorporating particles that increase the thermal conductivity such as alumina and zirconia in the back side filler, the thermal conductivity inside the solar cell module is improved even when a hot spot phenomenon occurs, and the temperature of the solar cell element is increased. A method for suppressing the rise has been proposed (see, for example, Patent Document 4). If the temperature rise of the solar cell module or the solar cell element can be suppressed, the temperature rise of the filler can be suppressed as a result, and it is considered possible to suppress the cloudiness of the filler. However, none of the patent documents describes the prevention of white turbidity of the filler accompanying the occurrence of the hot spot phenomenon.

  Further, as described above, ethylene-vinyl acetate copolymer resin is the center as a conventional filler, and it is good adhesiveness to prevent white turbidity of the filler using a copolymer resin obtained by polymerizing a silane compound. At present, there are not many proposals for.

Japanese Examined Patent Publication No. 62-14111 JP 2004-214641 A JP-A-6-181333 JP 2004-327630 A

  This invention is made | formed in view of the said situation, and it aims at providing the filler for solar cell modules which can suppress the cloudiness of resin for fillers when a hot spot phenomenon generate | occur | produces. .

  In order to achieve the above object, the present invention provides a filler resin containing a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polymerization polyethylene, and a nucleus dispersed in the filler resin. The filler for solar cell modules characterized by containing an agent is provided.

  According to the present invention, since the solar cell module filler contains a nucleating agent and the nucleating agent is dispersed in the filler resin, the nucleating agent can be used even when there is a temperature change due to a hot spot phenomenon or the like. Since a large number of small crystals are formed, the growth of crystals is hindered, so that it is possible to suppress white turbidity of the filler resin. Therefore, a solar cell module with a beautiful appearance can be obtained by using the solar cell module filler of the present invention. Moreover, when producing a solar cell module using the solar cell module filler of the present invention, since the solar cell module filler contains a nucleating agent, thermal contraction of the resin for the filler hardly occurs during lamination. The module processability can be improved. Furthermore, the solar cell module filler of the present invention contains a silane-modified resin, and this silane-modified resin has excellent adhesion to a transparent front substrate, a back surface protective sheet, etc., and the main chain is made of polyethylene. Therefore, there is an advantage that no harmful gas is generated and the working environment is not deteriorated.

  In the said invention, it is preferable that the said nucleating agent is contained within the range of 0.0005 weight%-2 weight%. If the content of the nucleating agent is too small, the effect of suppressing white turbidity of the filler resin may not be sufficiently obtained. If the content of the nucleating agent is too large, the transparent front substrate or the back surface may be formed when a solar cell module is obtained. This is because the adhesiveness to the protective sheet or the solar cell element may be reduced, the dispersibility in the resin for the filler may be deteriorated, and it may be economically disadvantageous. Furthermore, if the content of the nucleating agent is too large, the infrared transmittance decreases, that is, the heat ray absorbability may decrease and the heat absorption may increase, and the temperature inside the solar cell module may easily increase. Because.

  In the present invention, the nucleating agent is preferably a sorbitol nucleating agent.

  Furthermore, in this invention, it is preferable that the said resin for fillers contains the polyethylene for addition further. Since the silane-modified resin is high in cost, it is preferable to contain an additive polyethylene.

Further, in the present invention, the average density of the polyethylene contained in the resin for the filler ^is preferably in the range of ^{0.890g / cm 3 ~0.935g / cm 3} . If the average density of the polyethylene contained in the filler resin is as low as the above range, the crystallization of the polyethylene due to temperature change is hindered, so that the cloudiness of the filler resin can be effectively suppressed. Because it can.

In the present invention, the filler resin is preferably having a density containing polyethylene is in the range of ^{0.890g / cm 3 ~0.930g / cm 3} . By containing such low-density polyethylene, the average density of polyethylene contained in the filler resin can be lowered, so that crystallization of polyethylene due to temperature change can be prevented, and the filler resin It is because the cloudiness of can be effectively suppressed.

  Furthermore, in the present invention, Si (silicon) is preferably contained in the range of 8 ppm to 3500 ppm as the amount of polymerized Si. As described above, since the adhesiveness with the transparent front substrate or the back surface protective sheet is increased by containing the silane-modified resin, the adhesiveness with the glass or the like is insufficient when the amount of the polymerized Si is less than the above range. This is because, when the above range is exceeded, it is considered that the adhesiveness with glass or the like does not change and the cost is increased.

  Moreover, the filler for solar cell modules of the present invention may further contain at least one additive selected from the group consisting of a light stabilizer, an ultraviolet absorber, and a heat stabilizer. By containing these additives, stable mechanical strength, adhesive strength, yellowing prevention, crack prevention, and excellent processability can be obtained over a long period of time.

  Furthermore, when the solar cell module filler of the present invention is formed into a sheet shape having a thickness of 400 ± 10 μm, the average infrared transmittance in the wavelength range of 15000 nm to 25000 nm is preferably 40% or more. When the temperature of the solar cell element rises due to solar radiation heat or heat generated during solar cell power generation, the power generation efficiency may decrease due to its temperature characteristics, but the average infrared transmittance of the solar cell module filler is the above This is because, if the range is relatively high, the absorption of infrared rays (heat rays), that is, the endothermic property is low, and the temperature rise inside the solar cell module can be suppressed.

  The present invention also provides a solar cell module having a front side filler layer using the above-described filler for a solar cell module, wherein the gel fraction of the front side filler layer is 30% or less. . Since the solar cell module of the present invention has a front-side filler layer using the above-described filler for solar cell modules, the adhesion between the front-side filler layer and the transparent front substrate or the solar cell element is good and the appearance is beautiful. It can be. In addition, by setting the gel fraction of the front side filler layer in the above range, it is possible to seal in a short time when a solar cell module is manufactured, and further, no heat treatment or the like is required. In addition, since the gel fraction is low, the front-side filler layer can be easily softened and melted by heating, which enables reuse of solar cell elements and transparent front substrates used in solar cell modules, for example. It becomes possible.

Furthermore, the present invention provides a solar cell module comprising a filler resin containing a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polyethylene for polymerization, and a nucleating agent dispersed in the filler resin. a method of manufacturing a use filler masterbatch at least one of the nucleating agents and additives, having a density containing polyethylene and in the range of 0.890g ^/ cm ³ ~0.930g ^/ cm 3 The manufacturing method of the filler for solar cell modules characterized by using is provided.

  In the present invention, not only the nucleating agent is added to the solar cell module filler, but also a polyethylene having a relatively low density is used for the master batch. Since many small crystals are formed to prevent crystal growth, and by containing low-density polyethylene, the average density of polyethylene contained in the filler resin is lowered, which can prevent crystallization of polyethylene. It is possible to produce a solar cell module filler that is not easily clouded.

  In the present invention, since the solar cell module filler contains a nucleating agent, even when there is a temperature change due to a hot spot phenomenon or the like, it is possible to suppress the white turbidity of the filler resin.

  Hereinafter, the solar cell module filler of the present invention, a solar cell module using the same, and a method for manufacturing the solar cell module filler will be described.

A. First, the filler for solar cell modules of this invention is demonstrated.
The filler for solar cell module of the present invention includes a filler resin containing a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polymerization polyethylene, and a nucleating agent dispersed in the filler resin. It is characterized by containing.

  In the present invention, the solar cell module filler contains a nucleating agent, and since the nucleating agent is dispersed in the filler resin, the temperature rises due to heat generated by a hot spot phenomenon or the like. Even when there is a change in temperature, such as when the temperature is lowered due to a drop in temperature, the nucleating agent forms many small crystals that hinder crystal growth. Can do. In particular, when the temperature of the solar cell module filler is increased and then gradually cooled, the cloudiness of the filler resin can be effectively suppressed. Moreover, since the white turbidity of the resin for filler is suppressed, it is difficult to observe the white turbidity difference due to temperature change. That is, since the increase in haze (cloudiness) when the temperature-increased solar cell module filler is cooled is suppressed, the solar cell module filler of the present invention has little change in haze due to temperature change. . Therefore, the appearance is not easily damaged.

  Furthermore, when producing a solar cell module using the solar cell module filler of the present invention, for example, a transparent front substrate, a solar cell module filler, a solar cell element, a solar cell module filler, and a back surface protection sheet. Etc. are laminated one after another and vacuum lamination is performed by vacuum suction and thermocompression bonding. However, since the solar cell module filler contains a nucleating agent, the thermal shrinkage of the filler resin during the lamination is performed. It is difficult to occur and module processability can be improved.

In addition, the solar cell module filler of the present invention contains a silane-modified resin, and the silane-modified resin as described above has excellent adhesion to a transparent front substrate and a back surface protective sheet such as glass, and is mainly used. Since the chain is made of polyethylene, there is an advantage that no harmful gas is generated and the working environment is not deteriorated.
Hereinafter, each structure of the filler for solar cell modules of this invention is demonstrated.

1. Nucleating agent The nucleating agent used in the present invention suppresses the white turbidity of the resin for filler, and has the effect of forming many small crystals. The nucleating agent is not particularly limited as long as it is used for the purpose of improving the transparency of the filler resin described later. For example, a sorbitol-based nucleating agent, a carboxylic acid-based nucleating agent, and an organic phosphoric acid-based agent. Examples include nucleating agents.

Examples of the sorbitol nucleating agent include dibenzylidene sorbitol or a derivative thereof, specifically 1,3,2,4-di (meryl benzylidene) sorbitol, 1,3-chlorobenzylidene-2,4-methyl. Benzylidene sorbitol, 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-di (p-methylbenzylidene) sorbitol, 1,3,2,4-di (p-ethylbenzylidene) sorbitol, , 3: 2,4-bis-O-dimethylbenzylidene-D-sorbitol and the like can be used.
Examples of the carboxylic acid-based nucleating agent include aliphatic carboxylic acids, aliphatic dicarboxylic acids, aromatic carboxylic acids or metal salts of aromatic dicarboxylic acids, or metal salts of alkyl nucleus-substituted derivatives thereof. A sodium salt, calcium salt, or aluminum salt of stearic acid, adipic acid, or sebacic acid, or a sodium salt of benzoic acid or an aluminum salt of para-tert-butyl-benzoic acid can be used.
Examples of the organic phosphate nucleating agent include bis (2,4,8,10-tetra-tert-butyl-6-hydroxy-12H-dibenzo [d, f] [1,3,2] dioxaphossin- 6-oxide) aluminum hydroxide salt and the like.
Moreover, as said nucleating agent, a zeolite, a silica, a talc, a hydrotalcite etc. can also be used, for example.
These nucleating agents can be used alone or as a mixture.

  Among the above, a sorbitol nucleating agent is preferably used in the present invention. Furthermore, among the sorbitol nucleating agents, 1,3: 2,4-bis-O-dimethylbenzylidene-D-sorbitol is preferable.

  The nucleating agent is preferably contained in the solar cell module filler in the range of 0.0005 wt% to 2 wt%, more preferably in the range of 0.001 wt% to 0.45 wt%. Among them, it is most preferably contained in the range of 0.005 wt% to 0.25 wt%. This is because if the content of the nucleating agent is too small, the white turbidity suppressing effect of the filler resin may not be sufficiently obtained. On the other hand, when the content of the nucleating agent is too large, when it is a solar cell module, the adhesion with the transparent front substrate, the back surface protective sheet or the solar cell element is reduced, or the dispersibility in the resin for filler is poor. This is because it may become disadvantageous or economically disadvantageous. Moreover, when there is too much content of a nucleating agent, infrared transmittance | permeability will fall, ie, the heat ray absorptivity may fall and heat absorption may become high, and there exists a possibility that the temperature inside a solar cell module may rise easily. Because.

2. Resin for fillers The resin for fillers used in the present invention is not particularly limited as long as it contains a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polymerization polyethylene, Furthermore, it is preferable to contain polyethylene for addition. That is, the filler resin preferably contains a silane-modified resin and an additive polyethylene. This is because the silane-modified resin is expensive and therefore it is preferable to use polyethylene for addition in combination.

In the present invention, the average density of the polyethylene contained in the resin filler ^is preferably in the range of ^{0.890g / cm 3 ~0.935g / cm 3} , more preferably 0.890 g / cm ³ in the range of ~0.930g / cm ^3, most preferably in the range of ^{0.890g / cm 3 ~0.920g / cm 3} . If the average density of the polyethylene contained in the filler resin is relatively low as in the above range, it can prevent the polyethylene from crystallizing due to temperature changes such as when a hot spot phenomenon occurs. It is. Therefore, it is possible to effectively suppress white turbidity of the filler resin due to a temperature change.

  Here, the polyethylene contained in the resin for filler refers to the polyethylene for polymerization used for the silane-modified resin and the polyethylene for addition. As will be described later, for example, when multiple types of polyethylene are used as the polyethylene for polymerization and multiple types of polyethylene are used as the polyethylene for addition, the average density of these multiple types of polyethylene is in the filler resin. It becomes the average density of the contained polyethylene.

  The average density is a value obtained by multiplying the respective densities of polyethylene contained in the filler resin by the respective content ratios.

Further, the resin filler is preferably density containing polyethylene is in the range of ^{0.890g / cm 3 ~0.930g / cm 3} , more preferably density of 0.890g ^/ cm 3 ~0. It is preferred to contain polyethylene that is in the range of 928 g / cm ³ . If polyethylene having a relatively low density is contained in the filler resin, the average density of the polyethylene contained in the filler resin can be lowered, which may hinder polyethylene crystallization due to temperature changes. This is because the cloudiness of the resin for filler can be effectively suppressed.

  Here, the polyethylene having a density in a predetermined range refers to a polyethylene having a density in a predetermined range among the polyethylene for polymerization used for the silane-modified resin and the polyethylene for addition, as in the above case. For example, when multiple types of polyethylene are used as the polyethylene for polymerization and multiple types of polyethylene are used as the polyethylene for addition, the density of any one of these multiple types of polyethylene is within the above range. I just need it.

Thus, in the present invention, it is preferable that the average density of the polyethylene contained in the filler resin is in a predetermined range, and the filler resin contains polyethylene having the above density in the predetermined range. However, the resin for filler can contain polyethylene having a relatively high density within a range not exceeding the average density of preferable polyethylene.
Here, when producing the solar cell module filler of the present invention, the nucleating agent is dispersed in the filler resin. When dispersing the nucleating agent, polyethylene is pulverized to improve dispersibility. There is. High-density polyethylene can be pulverized more easily than low-density polyethylene and is excellent in processability, so that the cost can be reduced. Therefore, the average density of polyethylene contained in the resin for filler is within a predetermined range, and the resin for filler contains, for example, polyethylene having the above-mentioned density within a predetermined range and polyethylene having a relatively high density. In such a case, the solar cell module filler can be provided at low cost.

Furthermore, if the polyethylene more is used as the polyethylene for addition, the resin filler as polyethylene for addition, density is in the range of ^{0.890g / cm 3 ~0.935g / cm 3} , It is preferable to contain at least two types of polyethylene. The filler for solar cell modules of the present invention can be produced, for example, by heating and melting a nucleating agent or additive, a masterbatch containing polyethylene, and a resin main component. At this time, for example, by using polyethylene of a predetermined density for both the masterbatch and the resin main agent, the average density of polyethylene contained in the filler resin of the obtained solar cell module filler is further reduced. Therefore, the crystallization of polyethylene due to temperature change can be prevented, and the white turbidity of the filler resin can be more effectively suppressed.

  Hereinafter, other points of the silane-modified resin and the additive polyethylene contained in the filler resin and the filler resin will be described.

(1) Silane-modified resin The silane-modified resin contained in the filler resin in the present invention is obtained by polymerizing an ethylenically unsaturated silane compound and a polyethylene for polymerization, and the ethylenically unsaturated silane compound, the polyethylene for polymerization, and a radical. It can be obtained by mixing with a generator, melting and kneading at a high temperature, and graft-polymerizing an ethylenically unsaturated silane compound onto polyethylene for polymerization.

  The polymerization polyethylene used for the silane-modified resin is not particularly limited as long as it is a polyethylene polymer. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low density polyethylene, and ultra-low density. A polyethylene or a linear low density polyethylene is mentioned. These polyethylenes may be used alone or in combination of two or more. Among these, ultra-low density polyethylene, ultra-low density polyethylene, and linear low density polyethylene are preferably used. As described above, if the polyethylene for polymerization has a low density, the average density of the polyethylene contained in the resin for the filler is lowered, so that the crystallization of polyethylene due to temperature change can be prevented, and for the filler. This is because the white turbidity of the resin can be more effectively suppressed.

  The polymerization polyethylene is preferably polyethylene having many side chains. Usually, polyethylene with many side chains has a low density, and polyethylene with few side chains has a high density. Therefore, low density polyethylene is preferred. 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.

The density of the polyethylene for polymerization is the reason described ^above, is preferably in the range of ^{0.890g / cm 3 ~0.930g / cm 3} , more preferably 0.890g ^/ cm 3 ~0.928g ^/ cm Within the range of ³ .

  On the other hand, the ethylenically unsaturated silane compound used in the silane-modified resin is not particularly limited as long as it is graft-polymerized with the polymerization polyethylene. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl Tripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentyloxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltrimethylenedioxysilane, vinyltriethylenedioxysilane, vinylpropionyloxysilane , Vinyltriacetoxysilane, and at least one selected from the group consisting of vinyltricarboxysilane can be used. Of these, vinyltrimethoxysilane is preferably used.

The content of the ethylenically unsaturated silane compound in the solar cell module filler is preferably 10 ppm or more, more preferably 20 ppm or more. In the present invention, a transparent front substrate or a back sheet such as glass is obtained by using the ethylenically unsaturated silane compound polymerized with the above-described polymerization polyethylene, when a solar cell module is formed using a filler for a solar cell module. Adhesiveness with etc. is realized. When content of the said ethylenically unsaturated silane compound is less than the said range, adhesiveness with glass etc. is insufficient.
On the other hand, the content of the ethylenically unsaturated silane compound is preferably 4000 ppm or less, more preferably 3000 ppm or less. Although an upper limit is not limited from a viewpoint of adhesiveness with glass etc., if it exceeds the said range, adhesiveness with glass etc. will not change but cost will become high.

  The silane-modified resin is preferably contained in the solar cell module filler in the range of 1 to 80% by weight, and more preferably in the range of 5 to 70% by weight. The filler for solar cell modules of this invention becomes high [adhesiveness with glass etc.] by containing the said silane modified resin. Therefore, the above range is preferable from the viewpoints of adhesion to glass and the like and cost.

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 solar cell module filler of the present invention and the adhesiveness to the transparent front substrate and the back surface protective sheet.
Furthermore, the melting point of the silane-modified resin is preferably 110 ° C. or lower. When manufacturing a solar cell module using the solar cell module filler of the present invention, the above range is preferable in terms of workability and the like.

  Examples of the radical generator added to the silane-modified resin include hydroperoxides such as diisopropylbenzene hydroperoxide and 2,5-dimethyl-2,5-di (hydroperoxy) hexane; Oxide, 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 peroxyacete 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 radical generator is preferably contained in the silane-modified resin in an amount of 0.001% by weight or more. 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 above silane-modified resin may be used. it can.

(2) Additive polyethylene Examples of the additive polyethylene contained in the filler resin in the present invention include those similar to the polymerization polyethylene used in the silane-modified resin. In the present invention, it is particularly preferable that the additive polyethylene is the same polyethylene as the above-described polymerization polyethylene. Since the cost of the silane-modified resin is high, the solar cell is made of a filler resin containing a silane-modified resin and an additive polyethylene rather than constituting the filler for a solar cell module with a filler resin containing only the silane-modified resin. This is because it is more advantageous to construct the module filler.

  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. Moreover, 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 etc. of the filler for solar cell modules of this invention.
Furthermore, the melting point of the additive polyethylene is preferably 130 ° C. or lower. The above range is preferable from the viewpoint of workability and the like during the production of the solar cell module using the solar cell module filler of the present invention.
The melting point is a value measured by differential scanning calorimetry (DSC) in accordance with a plastic transition temperature measurement method (JIS K 7121). At this time, when two or more melting points exist, the higher temperature is defined as the melting point.

(3) Others In the present invention, it is preferable that Si (silicon) is contained in the solar cell module filler in the range of 8 ppm to 3500 ppm as a polymerized Si amount, and more preferably 10 ppm to 3000 ppm. It is contained within the range, most preferably within the range of 50 ppm to 2000 ppm. 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.

Here, only the filler for the solar cell module is heated, burned and ashed to convert the polymerized Si into SiO ₂ . Therefore, the above-mentioned amount of polymerized Si is quantified by the ICP emission analysis method using a high-frequency plasma emission spectrometer (ICPS8100 manufactured by Shimadzu Corporation) after melting the ash in an alkali and dissolving in pure water. It is set as the value measured by performing.

The filler resin in the present invention 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 for solar cell modules, adhesiveness with a transparent front substrate and a back surface protection sheet.
Moreover, it is preferable that melting | fusing point of resin for fillers is 130 degrees C or less. When manufacturing a solar cell module using the solar cell module filler of the present invention, the above range is preferable in terms of workability and the like. Moreover, it is because it can be easily reused, if a melting | fusing point is about this, when reusing the structural member of a solar cell module, for example, a solar cell element, and a transparent front substrate.
The melting point is a value measured by the method described above.

  Furthermore, the resin for filler in the present invention may contain a general resin conventionally used as a filler in addition to the silane-modified resin. Specifically, an ethylene-vinyl acetate copolymer (EVA) or the like can be used. This is because using such a resin together with a silane-modified resin is advantageous in terms of cost.

3. Additive The solar cell module filler of the present invention may contain additives such as a light stabilizer, an ultraviolet absorber, and a heat stabilizer, if necessary. The solar cell module filler of the present invention contains the above-mentioned silane-modified resin, and by adding a light stabilizer, an ultraviolet absorber, and a heat stabilizer to this, mechanical strength, adhesive strength, It is possible to obtain yellowing prevention, crack prevention, and excellent processability.

  The light stabilizer captures the active species at the start of photodegradation in the resin for filler and prevents photooxidation. Specific examples include light stabilizers such as hindered amine compounds and hindered piperidine compounds.

  UV absorbers absorb harmful UV rays in sunlight, convert them into innocuous heat energy within the molecule, and prevent excitation of active species that initiate photodegradation in filler resins It is. Specifically, benzophenone-based, benzotriazole-based, salicylate-based, acrylonitrile-based, metal complex-based, hindered amine-based, or ultrafine titanium oxide (particle diameter: 0.01 μm to 0.06 μm) and ultrafine zinc oxide ( Inorganic ultraviolet absorbers such as particle diameter: 0.01 μm to 0.04 μm) can be used.

  The heat stabilizer prevents oxidation deterioration of the filler resin. Specifically, tris (2,4-di-tert-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, tetrakis ( 2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite Phosphorus heat stabilizers such as: Lactone heat stabilizers such as reaction products of 8-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene; Phenol heat stabilizers Examples thereof include amine heat stabilizers, sulfur heat stabilizers, and the like. 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 above light stabilizer, ultraviolet absorber, heat stabilizer, etc. varies depending on the particle shape, density, etc., but in the range of 0.01 to 5% by weight in the solar cell module filler. It is preferable that

4). In the filler present invention for a solar cell module, the density of the encapsulant for a photovoltaic module ^is preferably 0.890g / cm ³ ~0.935g / cm 3, more preferably about 0.890 g / cm ³ a ~0.930g / cm ³ or so, and most preferably in the range of ^{0.890g / cm 3 ~0.920g / cm 3} . As described above, since the average density of polyethylene contained in the filler resin is preferably within a predetermined range, the density of the entire solar cell module filler is preferably within the above range. .

  The density is a value measured by the density gradient tube method specified in JIS K 7112. Specifically, the sample was put into a test tube containing liquids having different specific gravities, and the density was measured by reading the stopped position.

  Further, when the solar cell module filler of the present invention is used in a solar cell module, the solar cell module filler layer using the solar cell module filler will be described later in “B. Solar cell module”. It is preferable to show a low gel fraction as described in the column, and for this reason, the silane-modified resin does not need 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, the filler for solar cell modules substantially contains a silanol condensation catalyst that promotes the dehydration condensation reaction between silicone silanols such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctate, and dioctyltin dilaurate. Preferably not. 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 filler resin.

  Furthermore, when the solar cell module filler of the present invention is formed into a sheet shape having a thickness of 400 ± 10 μm, the average infrared transmittance in the wavelength range of 15000 nm to 25000 nm is preferably 40% or more, more preferably 60 % Or more, more preferably 70% or more. If the temperature of the solar cell element rises due to sunlight radiant heat, heat generated during solar cell power generation, etc., the power generation efficiency may decrease due to the temperature characteristics, but the infrared transmittance of the solar cell module filler is in the above range. If it is relatively high, the absorption of infrared rays (heat rays), that is, the endothermic property is low, and the solar cell module filler becomes difficult to store the heat generated by the solar cell element. Temperature rise can be suppressed.

  In addition, the said infrared transmittance measured the infrared absorption spectrum by the transmission method by infrared spectroscopy using FT-IR610 (made by JASCO Corporation), and the wavelength of 15000 nm-25000 nm of the obtained infrared absorption spectrum. The transmittances at every 1 nm are added and averaged.

  Furthermore, the solar cell module filler preferably has high light transmittance. Specifically, the total light transmittance of the solar cell module filler is preferably in the range of 70% to 100%, more preferably 80% to 100%, and most preferably 90% to 100%. Within range.

  In addition, the said total light transmittance can be measured by a normal method, for example, can be measured with a color computer.

  Moreover, when the solar cell module filler is formed into a sheet shape, the thickness thereof is preferably in the range of 50 to 2000 μm, and 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 becomes heavy and not only the workability such as installation is bad, but also in terms of cost. It is because it may become.

  In addition, since it describes in the column of the "C. manufacturing method of the filler for solar cell modules" mentioned later about the manufacturing method of the filler for solar cell modules of this invention, description here is abbreviate | omitted.

B. Next, the solar cell module of the present invention will be described.
The solar cell module of the present invention has a front-side filler layer using the above-described filler for solar cell module, and the gel fraction of the front-side filler layer is 30% or less. .

  FIG. 1 is a schematic cross-sectional view showing an example of the solar cell module of the present invention. As illustrated in FIG. 1, a plurality of solar cell elements 1 are arranged in the same plane, and a wiring electrode 2 and an extraction electrode 3 are arranged between the solar cell elements 1. Both sides of the solar cell element 1 are sandwiched between the front-side filler layer 4a and the back-side filler layer 4b. A transparent front substrate 5 is laminated outside the front-side filler layer 4a, and the back-side filler layer 4b A back surface protection sheet 6 is laminated on the outside. This solar cell module T may be fixed by an outer frame 7 such as aluminum. In the present invention, the solar cell module filler described above is used for the front filler layer 4a.

  In this invention, since it has the front side filler layer using the filler for solar cell modules mentioned above, it can be set as the solar cell module which has the advantage mentioned above. Specifically, it is possible to prevent the filler resin in the solar cell module filler from becoming clouded by the influence of a temperature change due to a hot spot phenomenon or the like, and to prevent the appearance from being damaged.

  Further, the gel fraction of the front side filler layer is 30% or less, preferably 10% or less, and particularly preferably 0%. Since the silane-modified resin used in the present invention does not form a crosslinked structure, 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 or a back surface protection sheet will not be recognized. Furthermore, if the gel fraction exceeds the above range, it becomes difficult to regenerate, for example, a solar cell element or a transparent front substrate.

  The gel fraction was determined by (1) weighing 1 g of the front-side filler layer and placing it in an 80-mesh wire mesh bag. (2) Putting the sample together with the wire mesh into a Soxhlet extractor to reflux xylene at the boiling point (3 ) After 10 hours of continuous extraction, the whole wire mesh and the sample are taken out, weighed after the drying treatment, and the weight% before and after extraction is compared and the weight% of the remaining insoluble matter is measured.

  Since the front-side filler layer has a role of bonding the solar cell element and the transparent front substrate, it is preferable that the adhesion with the transparent front substrate is high. Specifically, the peel strength with the transparent front substrate measured in the 180 ° peel test in a 25 ° C. atmosphere of the front side filler layer is preferably in the range of 1 N / 15 mm width to 150 N / 15 mm width, More preferably, it is within the range of 3 N / 15 mm width to 150 N / 15 mm width, and most preferably 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, it is preferable that the front-side filler layer keeps the adhesion for a long time, and the solar cell module is left at a temperature of 85 ° C. and a humidity of 85% for 1000 hours in a high-temperature and high-humidity state for 180 hours in a 25 ° C. atmosphere. The peel strength with the transparent front substrate measured in the peel test is preferably in the range of 0.5 N / 15 mm width to 140 N / 15 mm width, more preferably 3 N / 15 mm width to 140 N / 15 mm width, and even more preferably. Is in the range of 10 N / 15 mm width to 140 N / 15 mm width.
The measuring method is the same method as described above.

  The thickness of the front side filler layer is preferably in the range of 50 to 2000 μm, and 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 becomes heavy and not only the workability such as installation is bad, but also in terms of cost. It is because it may become.

  In the present invention, not only the front-side filler layer but also the back-side filler layer may use the solar cell module filler. At this time, the back side filler layer preferably has the same characteristics as those of the front side filler layer described above.

  The solar cell module of the present invention is formed by sequentially laminating, for example, a transparent front substrate, a solar cell module filler, a solar cell element, a solar cell module filler, a back surface protection sheet, and the like. A solar cell module can be obtained by using a normal molding method such as a lamination method in which suction is performed and thermocompression bonding is performed, and each layer is formed as an integral molded body.

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 laminating temperature is too low, it may not melt sufficiently and adhesion to the transparent front substrate, auxiliary electrode, solar cell element, back surface protection sheet, etc. may be deteriorated. This is because the crosslinking tends 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 laminating time is too short, it may not melt sufficiently and the adhesion to the same member may be deteriorated. If the laminating time is too long, it may cause a problem in the process, especially depending on the temperature and humidity conditions. This is because it causes an increase in the fraction.
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. .

  As the transparent front substrate used in the present invention, for example, a transparent composite sheet obtained by laminating and laminating glass, a fluorine resin sheet, a weather resistant film and a barrier film can be used.

  Moreover, as a back surface protection sheet used for the solar cell module of the present invention, for example, 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.

  In the solar cell module of the present invention, other layers can be arbitrarily added and laminated for purposes such as absorption of sunlight, reinforcement, and the like.

C. Next, the manufacturing method of the filler for solar cell modules of this invention is demonstrated.
The method for producing a solar cell module filler of the present invention was dispersed in a filler resin containing a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polyethylene for polymerization, and the filler resin. a method of manufacturing a filling material for a solar cell module containing a nucleating agent, at least one of the nucleating agents and additives and, in the range density of 0.890g ^/ cm ³ ~0.930g ^/ cm 3 It is characterized by using a masterbatch containing polyethylene which is

Conventionally, when preparing a masterbatch, in order to improve the dispersibility of the additive, the additive and polyethylene powder obtained by pulverizing polyethylene are often mixed. In this case, a relatively high density polyethylene is used. It was mainstream to use. This is because high-density polyethylene is more easily pulverized and has excellent processability, and can be reduced in cost. However, the high-density polyethylene has a drawback that it is easily crystallized, which causes the filler resin to become cloudy.
In the present invention, by using a masterbatch containing a nucleating agent or additive and a relatively low density polyethylene, the average density of polyethylene contained in the resulting solar cell module filler can be lowered. . Therefore, in addition to preventing crystal growth by adding a nucleating agent to the solar cell module filler, crystallization of polyethylene can be prevented by using a masterbatch containing polyethylene having a relatively low density. Therefore, it is possible to manufacture a solar cell module filler that does not easily become clouded even when a temperature change occurs.

In the present invention, as described in the column “A. Solar Cell Module Filler”, the filler resin is a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and polymerization polyethylene; Furthermore, it is preferable to contain polyethylene for addition. Therefore, it is preferable to prepare a filler for a solar cell module by mixing a silane-modified resin, an additive polyethylene, a nucleating agent, and, if necessary, an additive and heating and melting them. At this time, the mixing method is not particularly limited, but for at least one of the nucleating agent and the additive, a master batch in which the nucleating agent or the additive is mixed with polyethylene is used.
Hereinafter, the master batch used for this invention and the other point in the manufacturing method of the filler for solar cell modules of this invention are demonstrated.

1. Masterbatch for use in the master batch the present invention, the at least one nucleating agent and additives, in which density containing polyethylene and in the range of 0.890g ^/ cm ³ ~0.930g ^/ cm 3 There is no particular limitation as long as it is present.

  The master batch in the present invention can be divided into three embodiments depending on the presence or absence of a nucleating agent and an additive. A 1st aspect is a nucleating agent masterbatch in which a masterbatch contains a nucleating agent and polyethylene of a predetermined density, and a 2nd aspect is an antifungal agent master whose masterbatch contains an additive and polyethylene of a predetermined density. A third embodiment is a rust-proof masterbatch containing a nucleating agent, wherein the masterbatch contains a nucleating agent, an additive, and polyethylene of a predetermined density. When a nucleating agent master batch is used, the additives may be mixed as they are, may be mixed as an antifungal master batch, and the additives may not be used. Moreover, when using an anti-mold agent master batch, about a nucleating agent, you may mix as it is and you may mix as a nucleating agent master batch.

In either embodiment, the master batch has a density polyethylene are contained in the range of ^{0.890g / cm 3 ~0.930g / cm 3} , preferably a density of 0.890 g / ^cm 3 ~0 Polyethylene in the range of .928 g / cm ³ is contained. By using a masterbatch containing a relatively low density polyethylene as in the above range, the average density of polyethylene contained in the resulting solar cell module filler can be reduced, and the hot spot phenomenon is caused. This is because it is possible to obtain a solar cell module filler that does not easily become clouded even when a temperature change occurs.

Further, the average density of the polyethylene contained in the masterbatch is ^preferably in the range of ^{0.890g / cm 3 ~0.935g / cm 3} , more preferably 0.890g ^/ cm 3 ~0.930g ^/ in the range of cm ^3, and most preferably in the range of ^{0.890g / cm 3 ~0.920g / cm 3} . This is because if the average density of polyethylene is relatively low as in the above range, a solar cell module filler that is less likely to become cloudy can be obtained.

In the present invention, the master batch contains polyethylene having the above-mentioned density in a predetermined range, and the average density of polyethylene contained in the master batch is preferably in the predetermined range. A polyethylene having a relatively high density can be contained within a range not exceeding the average density of the preferred polyethylene.
As described above, high-density polyethylene is easier to pulverize and has better processability, and can be reduced in cost. Therefore, a relatively high density polyethylene is pulverized into powder, and this relatively high density polyethylene powder, the polyethylene having the above density within a predetermined range, and a nucleating agent or additive are mixed to obtain a master batch. The manufacturing cost of the masterbatch can be suppressed by manufacturing.

  In addition, let the said average density be the value which averaged each density of the polyethylene contained in a masterbatch by multiplying each content ratio.

  Further, the content of the nucleating agent in the nucleating agent masterbatch or the antifungal masterbatch containing the nucleating agent is not particularly limited as long as the white turbidity suppressing effect can be obtained, and is prepared using this masterbatch. It is preferable that the content of the nucleating agent in the solar cell module filler is an amount that falls within the predetermined range described in the column “A. Solar cell module filler”. It is preferably within the range of wt% to 20 wt%, more preferably within the range of 0.5 wt% to 15 wt%, and most preferably within the range of 1 wt% to 10 wt%.

  The content of the additive in the anti-corrosive master batch or the anti-corrosive master batch containing a nucleating agent is not particularly limited as long as it is an amount capable of imparting various characteristics.

  Since the nucleating agent and the additive are the same as those described in the column “A. Filler for solar cell module”, description thereof is omitted here.

  Moreover, in this invention, the silane modified resin may be contained in the masterbatch, and the polyethylene for addition may be contained in the masterbatch.

2. Next, a method for preparing the silane-modified resin used in the present invention will be described. 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.

  The heating temperature is preferably 300 ° C. or lower, more preferably 270 ° C. or lower, and a particularly preferable heating temperature is 230 ° C. or lower. The silane-modified resin is preferably melt-mixed within the above range because the silanol group portion is easily cross-linked and gelled by heating.

  Moreover, you may pelletize the obtained silane modified resin.

  The ethylenically unsaturated silane compound, the polyethylene for polymerization, the radical generator, and the silane-modified resin are the same as those described in the column “A. Filler for solar cell module” above. Description is omitted.

3. Method for Producing Solar Cell Module Filler Next, a method for producing the solar cell module filler of the present invention will be described. In the present invention, for example, the solar cell module filler can be produced by heating and melting the master batch, the silane-modified resin, and the additive polyethylene. Moreover, when the silane modified resin is contained in the master batch, the filler for the solar cell module can be produced by heating and melting the master batch and the polyethylene for addition. Furthermore, when the additive polyethylene is contained in the master batch, the filler for the solar cell module can be produced by heating and melting the master batch and the silane-modified resin.
At this time, as described above, the silane-modified resin can be pelletized, heated and melted again, and extruded, but the silane-modified resin, the additive polyethylene, and the master batch are mixed in the hopper of the extruder. It is also possible to put in and heat and melt in the cylinder, and the latter is superior in terms of cost.

As the addition amount of the nucleating agent masterbatch or the nucleating agent-containing antifungal masterbatch when these are heated and melted and mixed, the content of the nucleating agent in the filler for the solar cell module produced using this masterbatch is as described above. The amount is preferably within the predetermined range described in the column “A. Filler for Solar Cell Module”. Specifically, although it varies depending on the content of the nucleating agent in the nucleating agent masterbatch or the rusting agent masterbatch containing the nucleating agent, the range is usually 0.01 to 55 parts by weight with respect to 100 parts by weight of the resin main agent. And is preferably in the range of 0.02 to 15 parts by weight, more preferably in the range of 0.1 to 10 parts by weight.
In addition, a resin main agent means resin components other than a masterbatch.

  Moreover, it does not specifically limit as addition amount of an antifungal masterbatch.

There are no particular limitations on the method of heating and melting and mixing the masterbatch or the silane-modified resin.
The heating temperature is preferably 300 ° C. or lower, more preferably 270 ° C. or lower, and particularly preferably the heating temperature is 230 ° C. or lower. The silane-modified resin is preferably melt-mixed within the above range because the silanol group portion is easily cross-linked and gelled by heating.
The heating temperature at the time of heating and melting again is preferably 300 ° C. or lower, more preferably 270 ° C. or lower, and particularly preferably 230 ° C. or lower. As described above, the silane-modified resin is easily heated and melted in the above range because the silanol group portion is crosslinked and easily gelled by heating.

  In the present invention, when producing the solar cell module filler, it may be formed into a sheet after being heated and melted. In this case, it can be formed into a sheet having a thickness of 100 to 1500 μm by an existing method such as T-die or inflation after heating and melting, and can be used as a filler for a solar cell module.

  In addition, since it is the same as that of what was described in the column of the said "A. filler for solar cell modules" about the polyethylene for addition, description here is abbreviate | omitted.

  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 and comparative examples further illustrate the present invention.
[Example 1]
(Preparation of silane-modified resin)
For 100 parts by weight of a metallocene linear low density polyethylene (hereinafter referred to as LLDPE) having a density of 0.898 g / cm ³ , 2.5 parts by weight of vinyltrimethoxysilane and dichroic as a radical generator (reaction catalyst). 0.1 part by weight of mill peroxide was mixed and melted and kneaded at 200 ° C. to obtain a silane-modified resin.

(Preparation of solar cell module filler)
100 parts by weight of a metallocene linear low density polyethylene having a density of 0.920 g / cm ³ , 3.75 parts by weight of a benzotriazole-based UV absorber, 10 parts by weight of a hindered amine light stabilizer, and a phosphorus-based thermal stability A weathering agent master batch was prepared in advance by mixing 0.5 part by weight of the agent, melted, processed and pelletized. Further, a nucleating agent master batch in which a metallocene linear low density polyethylene having a density of 0.920 g / cm ³ and a sorbitol nucleating agent were mixed, melted, processed, and pelletized was prepared in advance. At this time, the amount of sorbitol-based nucleating agent added in the nucleating agent master batch was 5% by weight.

5 parts by weight of the weathering agent masterbatch, 1 part by weight of the nucleating agent masterbatch, and a metallocene linear low density with a density of 0.900 g / cm ³ as an additive polyethylene with respect to 20 parts by weight of the silane-modified resin. A mixture of 80 parts by weight of polyethylene is filled for a solar cell module having a total thickness of 400 μm at an extrusion temperature of 230 ° C. and a take-off speed of 2.3 m / min, using a φ150 mm extruder and a film molding machine having a 1000 mm wide T die. A material was prepared. The content of the nucleating agent in the obtained solar cell module filler was 0.047% by weight.

(Production of solar cell module)
A glass plate (transparent front substrate) having a thickness of 3 mm, a solar cell module filler having a thickness of 400 μm, a solar cell element made of polycrystalline silicon, a filler having a thickness of 400 μm and a filler having a thickness of 38 μm. A laminated sheet composed of a vinyl fluoride resin sheet (PVF), a 30 μm thick polyethylene terephthalate sheet and a 38 μm thick polyvinyl fluoride resin sheet (PVF) is laminated in this order, and the solar cell element surface is For this purpose, a solar cell module was manufactured by pressure bonding at 150 ° C. for 15 minutes using a vacuum laminator for manufacturing the solar cell module.

[Example 2]
100 parts by weight of a metallocene linear low density polyethylene having a density of 0.900 g / cm ³ , 3.75 parts by weight of a benzotriazole-based UV absorber, 10 parts by weight of a hindered amine light stabilizer, A weathering agent master batch was prepared in advance by mixing 0.5 part by weight of the agent, melted, processed and pelletized. Further, a nucleating agent master batch in which a metallocene linear low density polyethylene having a density of 0.900 g / cm ³ and a sorbitol nucleating agent were mixed, melted, processed, and pelletized was prepared in advance. At this time, the amount of sorbitol-based nucleating agent added in the nucleating agent master batch was 5% by weight.

5 parts by weight of the weathering agent masterbatch, 1 part by weight of the nucleating agent masterbatch, and a metallocene having a density of 0.900 g / cm ³ as polyethylene for addition with respect to 20 parts by weight of the silane-modified resin used in Example 1. 80 parts by weight of linear low density polyethylene was mixed, and a solar cell module filler was produced in the same manner as in Example 1. The content of the nucleating agent in the obtained solar cell module filler was 0.047% by weight.
And the solar cell module was produced by the method similar to Example 1. FIG.

[Examples 3 to 5]
The kind of nucleating agent masterbatch, the silane-modified resin, the polyethylene for addition, the kind of weathering agent masterbatch and the amount of addition thereof are the same as in Example 2, and the amount of sorbitol nucleating agent added in the nucleating agent masterbatch And the addition amount of a nucleating agent masterbatch was changed as shown in following Table 1, and the filler for solar cell modules was produced by the method similar to Example 2. FIG. In addition, Table 1 below shows the content of the nucleating agent in the obtained filler for solar cell modules.
And the solar cell module was produced by the method similar to Example 1. FIG.

[Example 6]
Example 2 was used except that 80 parts by weight of ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate (VA) content of 12% and a density of 0.930 g / cm ³ was used instead of 80 parts by weight of polyethylene for addition. Similarly, a solar cell module filler and a solar cell module were produced.

[Example 7]
(Preparation of silane-modified resin)
For 100 parts by weight of a metallocene linear low density polyethylene (hereinafter referred to as LLDPE) having a density of 0.910 g / cm ³ , 2.5 parts by weight of vinyltrimethoxysilane and dichroic as a radical generator (reaction catalyst). 0.1 part by weight of mill peroxide was mixed and melted and kneaded at 200 ° C. to obtain a silane-modified resin.

(Preparation of solar cell module filler)
To 100 parts by weight of medium density polyethylene having a density of 0.940 g / cm ³ , 3.75 parts by weight of a benzotriazole ultraviolet absorber, 10 parts by weight of a hindered amine light stabilizer, and 0.2% of a phosphorus heat stabilizer. A weathering agent master batch was prepared in advance by mixing with 5 parts by weight, melting, processing, and pelletizing. Further, a nucleating agent master batch in which medium density polyethylene having a density of 0.940 g / cm ³ and a sorbitol nucleating agent were mixed, melted, processed, and pelletized was prepared in advance. At this time, the amount of sorbitol-based nucleating agent added in the nucleating agent master batch was 5% by weight.

For 20 parts by weight of the silane-modified resin, 5 parts by weight of the weathering agent master batch, 1 part by weight of the nucleating agent master batch, and 80 parts by weight of medium density polyethylene having a density of 0.940 g / cm ³ as an additive polyethylene. A filler for a solar cell module having a total thickness of 400 μm was prepared at an extrusion temperature of 230 ° C. and a take-off speed of 2.3 m / min using a φ150 mm extruder and a film molding machine having a 1000 mm wide T-die. . The content of the nucleating agent in the obtained solar cell module filler was 0.047% by weight.

(Production of solar cell module)
A solar cell module was produced in the same manner as in Example 1.

[Comparative Example 1]
(Preparation of silane-modified resin)
For 100 parts by weight of a metallocene linear low density polyethylene (hereinafter referred to as LLDPE) having a density of 0.910 g / cm ³ , 2.5 parts by weight of vinyltrimethoxysilane and dichroic as a radical generator (reaction catalyst). 0.1 part by weight of mill peroxide was mixed and melted and kneaded at 200 ° C. to obtain a silane-modified resin.

(Preparation of solar cell module filler)
For 100 parts by weight of medium density polyethylene with a density of 0.940 g / cm ³ , 3.75 parts by weight of a benzotriazole UV absorber, 10 parts by weight of a hindered amine light stabilizer, and 20 parts by weight of a phosphorus heat stabilizer. A weatherproofing agent master batch was prepared in advance by mixing and melting, processing, and pelletizing.

A φ150 mm extruder for mixing 20 parts by weight of the silane-modified resin with 5 parts by weight of the weathering agent masterbatch and 80 parts by weight of medium density polyethylene having a density of 0.940 g / cm ³ as polyethylene for addition, Using a film molding machine having a 1000-mm wide T-die, a solar cell module filler having a total thickness of 400 μm was produced at an extrusion temperature of 230 ° C. and a take-off speed of 2.3 m / min.

(Production of solar cell module)
A solar cell module was produced in the same manner as in Example 1.

[Characteristic evaluation]
The following tests were conducted on the solar cell module fillers and solar cell modules in Examples 1 to 7 and Comparative Example 1. The measurement results of each test are shown in Table 2 below.

(1) Haze measurement (room temperature standing)
About the filler for solar cell modules, haze (%) was measured with SM color computer (SM-C) by Suga Test Instruments Co., Ltd. Specifically, a solar cell module filler is sandwiched between blue and white float glass having a total light transmittance of 91%, a haze of 0.2%, and a thickness of 3 mm at 150 ° C. with a vacuum laminator for manufacturing a solar cell module. After pressure bonding for 15 minutes, the sample was cooled by being left at room temperature (25 ° C.) to prepare a sample for haze measurement, and the haze was measured for this sample.

(Rapid cooling)
The sample for haze measurement was put into an oven at 150 ° C. for 1 hour, taken out, immediately put into a freezer at −20 ° C. and left for 10 minutes. The sample was taken out from the freezer and allowed to stand at room temperature (25 ° C.). After the sample temperature reached room temperature, haze was measured with an SM color computer (SM-C) manufactured by Suga Test Instruments Co., Ltd.

(Slow cooling)
After putting the above sample for haze measurement into an oven at 150 ° C. for 1 hour, the set temperature of the oven was gradually lowered and cooled to room temperature (25 ° C.) at a cooling rate of 1 ° C./min. Then, haze was measured with SM color computer (SM-C) by Suga Test Instruments Co., Ltd.

(2) Measurement of adhesion Room temperature of the solar cell module filler layer and the transparent front substrate immediately after the production of the solar cell module and after being left for 1000 hours in a high-temperature and high-humidity state at a temperature of 85 ° C. and a humidity of 85% ( The peel strength (N / 15 mm width) under 25 ° C) was measured.

(3) Hot spot test The solar cell module was subjected to a hot spot test based on JIS standard C8917, and the appearance after the test was evaluated.

(4) Measurement of average infrared transmittance Using FT-IR610 (manufactured by JASCO Corporation), an infrared absorption spectrum was measured by a transmission method by infrared spectroscopy, and the wavelength of the obtained infrared absorption spectrum was 15000 nm to The transmittance for every 1 nm at 25000 nm was added and the average value was taken as the average infrared transmittance.

As is clear from Table 2, the haze of the solar cell module filler in Examples 1 to 7 has little difference depending on the cooling rate, and the solar cell module in Examples 1 to 7 has a hot spot test as compared with Comparative Example 1. Later, white turbidity hardly occurred. Moreover, the filler for solar cell modules of Examples 1-4, 6, and 7 was excellent in adhesiveness with the transparent front substrate under room temperature (25 degreeC). On the other hand, in the solar cell module filler in Example 5, since the amount of the nucleating agent was large, the adhesion with the transparent front substrate was deteriorated after the high temperature and high humidity test.
On the other hand, in the solar cell module in the comparative example 1, since the nucleating agent was not used for the filler for solar cell modules, it became cloudy after the hot spot test.

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

Explanation of symbols

4a ... Front side filler layer T ... Solar cell module

Claims (11)

  A solar cell module comprising: a filler resin containing a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and polymerization polyethylene; and a nucleating agent dispersed in the filler resin. Filler.   2. The solar cell module filler according to claim 1, wherein the nucleating agent is contained within a range of 0.0005 wt% to 2 wt%.   The said nucleating agent is a sorbitol type | system | group nucleating agent, The filler for solar cell modules of Claim 1 or Claim 2 characterized by the above-mentioned.   The solar cell module filler according to any one of claims 1 to 3, wherein the filler resin further contains polyethylene for addition. The average density of the polyethylene contained in the filling material for resin ^is any of from claim 1, wherein in the range of 0.890g / cm ³ ~0.935g / cm 3 to claim 4 The filler for solar cell modules according to claim. The resin filler is any one of claims from claim 1, characterized in that density containing polyethylene is in the range of 0.890g ^/ cm ³ ~0.930g ^/ cm 3 to claim 5 The filler for solar cell modules described in 1.   The filler for a solar cell module according to any one of claims 1 to 6, wherein Si (silicon) is contained in the range of 8 ppm to 3500 ppm as the amount of polymerized Si.   Furthermore, at least 1 type of additive chosen from the group which consists of a light stabilizer, a ultraviolet absorber, and a heat stabilizer is contained, The claim in any one of Claim 1-7 characterized by the above-mentioned. The filler for solar cell modules as described.   The average infrared transmittance in a wavelength range of 15000 nm to 25000 nm is 40% or more when the solar cell module filler is formed into a sheet shape having a thickness of 400 ± 10 μm. The solar cell module filler according to any one of the preceding claims.   It has a front side filler layer using the filler for solar cell modules according to any one of claims 1 to 9, and the gel fraction of the front side filler layer is 30% or less. A solar cell module characterized by. Manufacture of a filler for a solar cell module comprising a filler resin containing a silane-modified resin obtained by polymerizing an ethylenically unsaturated silane compound and a polymerization polyethylene, and a nucleating agent dispersed in the filler resin. a method, characterized one of at least one of the nucleating agents and additives, the use of masterbatch density containing polyethylene and in the range of 0.890g ^/ cm ³ ~0.930g ^/ cm 3 The manufacturing method of the filler for solar cell modules.

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