JP6286986B2 - Encapsulant masterbatch for solar cell module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sealing material master batch for a solar cell module and a method for producing the same.

  In recent years, solar cells as a clean energy source have attracted attention due to the growing awareness of environmental issues. Currently, various types of solar cell modules have been developed and proposed. Generally, a solar cell module has a configuration in which a transparent front substrate, a solar cell element, and a back surface protection sheet are laminated via a sealing material for a solar cell module.

  Each member constituting the solar cell module or the like is always exposed to a harsh environment such as strong ultraviolet rays, heat rays, wind and rain. For this reason, each member which comprises a solar cell module needs to be equipped with durability over a long period of time on these conditions.

  As a sealing material for a solar cell module, a material using EVA (ethylene-vinyl acetate copolymer), which is excellent in transparency, adhesion, and the like, as a base resin has been widely used. However, in recent years, development of a sealing material using a polyethylene resin having a transparency equivalent to EVA and excellent in hydrolysis resistance as compared with EVA as a base resin has been progressing.

  When a polyethylene resin is employed as the base resin, it is known that the adhesion with glass or the like can be improved by blending a silane coupling agent. In order to further improve the adhesion, and in order to further improve the adhesion, a low-density, low-melting silane-modified polyethylene resin obtained by graft-polymerizing an ethylenically unsaturated silane compound to a linear low-density polyethylene, A sealing material using a sealing material composition to which a crosslinking agent is added has been proposed (see Patent Document 1).

  On the other hand, a sealing material for a solar cell module that is assumed to be exposed to strong sunlight over a long period of time is required to have extremely high light resistance. As a sealing material having such light resistance, for example, a sealing material using a hindered amine light resistance stabilizer (HALS) has been proposed. (See Patent Document 2).

  And as a manufacturing method of the sealing material composition for improving the dispersibility of HALS in a sealing material composition, HALS knead | mixed with a sealing material composition is masterbatch beforehand, Then, silane modification | denaturation The manufacturing method of the sealing material composition knead | mixed with the material of other sealing material compositions, such as resin, by kneading | mixing etc. is disclosed (refer patent document 3).

  Based on the above knowledge, in recent years, 4) composition materials of 1) a low density polyethylene resin used as a base resin, 2) a silane-modified polyethylene resin, 3) a light-resistant stabilizer, and 4) a crosslinking agent are mixed. A method of producing a polyethylene-based sealing material having excellent adhesion and light resistance by smelting and extrusion molding is widely used.

  However, when the four types of compositions 1) to 4) are kneaded, classification is likely to occur, and there is still room for improvement in dispersibility. In addition, complicated delivery management of other types of composition materials has also been an obstacle to improving productivity.

  It contains a silane-modified polyethylene-based resin and a light-resistant stabilizer, and has excellent adhesiveness and light resistance, while maintaining its preferable physical properties, and with higher productivity. There was a need for new means that could be produced.

JP 2012-234965 A JP 2004-214641 A JP 2012-9963 A

  For example, in order to produce a sealing material for a polyethylene-based solar cell module having excellent adhesion and light resistance as described above, a master batch containing both a silane-modified polyethylene resin and a light-resistant stabilizer is produced. If possible, it is possible to increase the productivity while maintaining the physical properties required for the sealing material for the solar cell module.

  As a method for obtaining the above-mentioned silane-modified polyethylene resin, a method in which a base resin to which a silane coupling agent and an organic peroxide are added is heated and crosslinked to cause a radical reaction to proceed is generally used. is there.

  Therefore, when a light stabilizer is further added in addition to the base resin, the silane coupling agent, and the organic peroxide during the above heat treatment, the light stabilizer such as a hindered amine light stabilizer (HALS) is Since they are intended to supplement radicals, the progress of the radical reaction necessary for the production of the silane-modified polyethylene resin is hindered, and the polymerization between the base resin and the silane coupling agent tends not to proceed sufficiently. If it does so, the improvement effect of the adhesiveness which a silane modified polyethylene-type resin can originally exhibit will also become inadequate.

  As a masterbatch that can improve the productivity while maintaining various physical properties required for a sealing material for solar cell modules for the above reasons, it contains both a silane-modified polyethylene resin and a light-resistant stabilizer. In practice, it was extremely difficult to produce a master batch.

  The present invention contains a silane-modified polyethylene resin and a light stabilizer together, and produces a sealing material for a solar cell module that is excellent in adhesion and light resistance under higher productivity than conventional methods. It aims at providing the sealing material masterbatch which enables this.

  The inventors of the present invention have made extensive studies on means for obtaining a masterbatch containing a silane-modified polyethylene resin and a light-resistant stabilizer. As a result, the addition amount of each of the silane coupling agent and the organic peroxide is limited to a unique range different from the conventional general range, thereby maintaining the effect of improving adhesion and light resistance, It has been found that a masterbatch containing a modified polyethylene resin and a light-resistant stabilizer can be produced, and the present invention has been completed. More specifically, the present invention provides the following.

(1) A method for producing a sealing material master batch for a solar cell module containing a silane-modified polyethylene resin and a light-resistant stabilizer, comprising a linear low-density polyethylene having a density of 0.900 g / cm ³ or less. A masterbatch base resin, 4 to 6 parts by weight of a silane coupling agent with respect to 100 parts by weight of the masterbatch base resin, and 0.1 to 100 parts by weight of the masterbatch base resin. 160 parts by weight of organic peroxide for masterbatch of not less than 0.2 parts by weight and not more than 0.5 parts by weight and not more than 5 parts by weight with respect to 100 parts by weight of the base resin for masterbatch. The manufacturing method of the sealing material masterbatch including the process knead | mixed at the temperature below 280 degreeC.

  (2) The manufacturing method of the sealing material masterbatch as described in (1) whose said light-resistant stabilizer is a hindered amine type light-resistant stabilizer.

  (3) The manufacturing method of the sealing material masterbatch as described in (1) or (2) whose said organic peroxide for masterbatch is a dialkyl peroxide or peroxycarbonate.

  (4) The manufacturing method of the sealing material masterbatch for solar cell modules in any one of (1) to (3) whose said silane coupling agent is a silane coupling agent which has a vinyl group.

(5) A sealing material master batch for a solar cell module manufactured by the manufacturing method according to any one of (1) to (4), an organic peroxide for a sealing material composition, and a density of 0.900 g Of a sealing material for a solar cell module that is melt-extruded at 160 ° C. or more and 260 ° C. or less of a sealing material composition containing a base resin for a sealing material composition comprising a polyethylene-based resin of / cm ³ or less Production method.

(6) Density 0.900 g / cm ³ or less of linear low density polyethylene 6 parts by weight of silane 4 parts by weight or more and masterbatch-based resin to the masterbatch for 100 parts by weight of the base resin which comprises A silane-modified polyethylene resin obtained by graft polymerization with a coupling agent and 0.5 to 5 parts by weight of a light-resistant stabilizer with respect to 100 parts by weight of the masterbatch base resin are mixed. An encapsulant master batch for solar cell modules.

  According to the present invention, in the production of a sealing material for a solar cell module based on a polyethylene-based resin, while maintaining adhesion and light resistance in a desirable range, under higher productivity than conventional methods, A sealing material having such excellent physical properties can be provided.

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

  Hereinafter, a sealing material masterbatch for the solar cell module of the present invention, a sealing material composition containing the masterbatch, a sealing material for a solar cell module that can be manufactured using the sealing material composition, And the solar cell module using the same sealing material is demonstrated in detail in order.

<Encapsulant master batch>
First, the encapsulant master batch for the solar cell module of the present invention (hereinafter also simply referred to as “encapsulant master batch”) will be described.

[Encapsulant master batch]
The encapsulant masterbatch of the present invention is a so-called masterbatch used for mixing a silane-modified polyethylene resin or the like having a required concentration with an encapsulant composition used for manufacturing a solar cell module. In general, the masterbatch contains an additive component such as a silane-modified polyethylene resin at a high concentration, and is pelletized for easy adjustment. The shape of the pellet may be any shape such as a columnar shape, a prismatic shape, a spherical shape, an elliptical spherical shape, etc., but is preferably a cylindrical shape or a prismatic shape, and the average diameter of the circular cross section is 1 to 10 mm, particularly 2 to 5 mm. A columnar shape having an average length of 1 to 10 mm, particularly 2 to 5 mm is particularly preferable.

  The sealing material composition according to the present invention uses low-density polyethylene as a base resin for the sealing material composition, the sealing material master batch of the present invention, which will be described in detail later, and an organic material for the sealing material composition. And a peroxide. And the said sealing material composition is melt-extruded and becomes the sealing material for solar cell modules which concerns on this invention.

(Silane-modified polyethylene resin)
The encapsulant masterbatch of the present invention contains a silane-modified polyethylene resin as a main component. The silane-modified polyethylene resin is based on linear low density polyethylene (LLDPE) having a density of 0.900 g / cm ³ or less, a silane coupling agent is added to the resin, and the base is added in the presence of an organic peroxide. A graft copolymer obtained by graft polymerization using a resin as a main chain and a silane coupling agent (ethylenically unsaturated silane compound) as a side chain. Since the silane-modified polyethylene resin, which is such a graft copolymer, has a high degree of freedom of silanol groups that contribute to adhesion, it can improve the adhesion of the sealing material to other members in the solar cell module. Can do.

As a base resin for producing a silane-modified polyethylene resin (hereinafter also referred to as “base resin for masterbatch”), linear low density polyethylene (LLDPE) having a density of 0.900 g / cm ³ or less is used. LLDPE is synthesized using a metallocene catalyst that is a single site catalyst. Such polyethylene has few side chain branches and a uniform comonomer distribution. For this reason, molecular weight distribution is narrow, it is possible to make it the above ultra-low density, and a softness | flexibility can be provided with respect to a sealing material. As a result of the flexibility imparted to the sealing material, the adhesion between the sealing material and a transparent front substrate such as glass can be enhanced.

  Since LLDPE has a narrow crystallinity distribution and a uniform crystal size, there is no LLDPE having a large crystal size. In addition, the crystallinity itself is low due to the low density. For this reason, it is excellent in transparency when processed into a sheet shape. Therefore, even if the sealing material which consists of a sealing material composition containing the sealing material masterbatch of this invention is arrange | positioned between a transparent front substrate and a solar cell element, power generation efficiency hardly falls.

  As the α-olefin of LLDPE, an α-olefin having no branch is preferably used, and among these, 1-hexene, 1-heptene or 1-octene which is an α-olefin having 6 to 8 carbon atoms is preferable. Is particularly preferably used. When the number of carbon atoms of the α-olefin is 6 or more and 8 or less, the sealing material can be given good flexibility and good strength. As a result, the adhesion between the sealing material and the transparent front substrate such as glass is further enhanced.

  The silane coupling agent to be graft polymerized with LLDPE which is the base resin for masterbatch is not particularly limited, but those having a vinyl group can be particularly preferably used from the viewpoint of improving the film forming property. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentyloxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltri A silane coupling agent consisting of one or more selected from methylenedioxysilane, vinyltriethylenedioxysilane, vinylpropionyloxysilane, vinyltriacetoxysilane, and vinyltricarboxysilane can be preferably used.

  These silane coupling agents are added in a proportion of 4 to 6 parts by weight with respect to 100 parts by weight of the masterbatch base resin. In the present invention based on the premise that a masterbatch containing both a light-resistant stabilizer and a silane-modified polyethylene resin is used, there is also an influence of radical predation by the light-resistant stabilizer, and if the addition amount is less than 4 parts by weight, sealing is performed. The adhesion of the material, particularly the initial adhesion to glass, is insufficient. On the other hand, when the addition amount exceeds 6 parts by weight, the effect of improving the adhesion beyond that is extremely small, and the risk of bleeding out due to the unreacted agent increases, which is not preferable.

(Organic peroxide)
Examples of the organic peroxide used to promote the copolymerization of the masterbatch base resin and the silane coupling agent (hereinafter also referred to as “organic peroxide for masterbatch”) include alkyl peroxyesters, Peroxycarbonate, dialkyl peroxide, and the like can be used, and among them, dialkyl peroxide or peroxycarbonate can be preferably used.

  The compounding quantity of these organic peroxides for master batches shall be 0.1 to 0.2 weight part with respect to 100 weight part of base resin for master batch. When the blending amount is less than 0.1 parts by weight, polymerization of the masterbatch base resin and the silane coupling agent does not proceed sufficiently in the presence of the light-resistant stabilizer. On the other hand, if it exceeds 0.2 parts by weight, the fluidity of the material resin will be insufficient and it will be difficult to make a masterbatch.

(Light stabilizer)
The encapsulant masterbatch of the present invention further contains a light resistant stabilizer. The sealing material masterbatch of the present invention is a masterbatch in which a silane-modified polyethylene resin and a light-resistant stabilizer, which have been conventionally difficult to be masterbatch by sufficient mixing, are sufficiently mixed. And In the present specification, “mixing” means a state in which a masterbatch that is a mixture of the composition materials is formed in a state in which the composition materials are sufficiently dispersed without causing classification between the composition materials. I shall say that.

  As the light-resistant stabilizer added to the masterbatch of the present invention, a hindered amine light-resistant stabilizer (HALS) can be preferably used. In general, many types of HALS are known from low molecular weight compounds to high molecular weight compounds. When used in a sealing material composition for a solar cell module, bleeding out often occurs when a low molecular weight, that is, a molecular weight of less than 1200 is used. In this case, the light transmittance is low. It becomes smaller and transparency is lowered. Since a decrease in the transparency of the sealing material leads to a decrease in the power generation efficiency of the solar cell module, a high molecular weight molecular weight of 1200 or more is often used as the light resistance stabilizer used in the sealing material composition. .

  Conventionally, as high-light-weight type hindered amine light stabilizers that have been generally used as light-resistant stabilizers for encapsulant compositions for solar cell modules, specific examples are listed in Patent Document 2. Yes. For example, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4 -Piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (molecular weight 2,000-3,100); dimethyl succinate and 4-hydroxy-2,2, Polymer of 6,6-tetramethyl-1-piperidineethanol (molecular weight 3,100 to 4,000); N, N ′, N ″, N ″ ′-tetrakis- (4,6-bis- (butyl- ( N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine (molecular weight 2,286) and the succinate Dimethyl acid and 4-hydroxy-2, , 6,6-tetramethyl-1-piperidineethanol polymer mixture; dibutylamine, 1,3,5-triazine, N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl 1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate (molecular weight 2,600-3,400), and 4-acryloyloxy- 2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-acryloyloxy-1-ethyl-2,2,6,6-tetramethyl Piperidine, 4-acryloyloxy-1-propyl-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1-butyl-2,2,6,6-tetramethyl Piperidine, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6,6-pentamethylperidine, 4-methacryloyloxy-1-ethyl-2, 2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1-butyl-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4 -Copolymers of ethylene and cyclic aminovinyl compounds such as crotonoyloxy-1-propyl-2,2,6,6-tetramethylpiperidine (ethylene / cyclic aminovinyl compound copolymer) (molecular weight of 1200 or more), etc. Or a mixture thereof.

  Although the compounding quantity of these light-resistant stabilizers is not necessarily limited, it adds in the ratio of 0.5 to 5 weight part with respect to 100 weight part of base resins for masterbatches. When the blending amount of the light-resistant stabilizer is less than 0.5 parts by weight, the light-resistant stabilizer is not sufficiently dispersed in the base resin, and the desired light resistance may not be stably obtained. On the other hand, when the blending amount of the light stabilizer exceeds 5 parts by weight, even if the organic peroxide for masterbatch is sufficiently added within the above range due to excessive radical scavenging of the light stabilizer, Graft polymerization of the base resin for use with the silane coupling agent does not proceed sufficiently.

[Manufacturing method of encapsulant master batch]
In order to produce the encapsulant masterbatch, the masterbatch base resin, the silane coupling agent, and the masterbatch organic peroxide are kneaded in the presence of the masterbatch organic peroxide. As a kneading machine for kneading, a conventionally known kneading machine can be used. For example, batch type pressure kneaders, open kneaders, Banbury mixers, single screw extruders, twin screw kneaders, roll kneaders and the like can be exemplified. What is necessary is just to adjust the addition amount of each material suitably within the above-mentioned range.

Kneading the material of the encapsulant masterbatch, using the desired kneader exemplified above, for example, a pressure 500~4000Kg / cm ^2-position, preferably, 1000~4000Kg / cm ^2-position, It is performed under a temperature condition of 160 ° C. or more and 260 ° C. or less, preferably 180 to 240 ° C. Then, in the presence of the organic peroxide for the masterbatch, the base resin for the masterbatch and the silane coupling agent are randomly copolymerized simultaneously or stepwise, and further, random generated by the copolymerization. The part of the silane compound constituting the copolymer is modified or condensed.

  As described above, the encapsulant masterbatch and the production method thereof of the present invention mainly limit the addition amount of the silane coupling agent and the addition amount of the organic peroxide for masterbatch to the range specific to the present invention. Therefore, even if a sufficient amount of light-resistant stabilizer such as HALS that supplements radicals is added, the graft polymerization of the base resin for masterbatch and the silane coupling agent necessary for the production of the silane-modified polyethylene resin is appropriately and sufficiently performed. It is characterized in that it can be advanced.

<Encapsulant composition>
Next, the encapsulant composition according to the present invention prepared by including the encapsulant master batch of the present invention (hereinafter, also simply referred to as “encapsulant composition”) will be described.

  The sealing material composition includes a base resin for a sealing material composition (hereinafter also referred to as “base resin for sealing material composition”), a resin, and the sealing of the present invention described in detail above. A material master batch and an organic peroxide for a sealing material composition (hereinafter, also referred to as “organic peroxide for a sealing material composition”).

As the base resin for the sealing material composition, low density polyethylene having a density of 0.900 g / cm ³ or less is used. This base resin preferably has a melting point of less than 80 ° C., is unmodified with silane, and is composed of an olefin monomer. In addition, the base resin for a sealing material composition preferably has a melting point difference from the sealing material master batch within 20 ° C, more preferably within 10 ° C. Furthermore, the base resin for the sealing material composition is preferably the same resin as the base resin for the masterbatch.

  Here, the MFR of the base resin for the sealing material composition is preferably 20.0 g / 10 min or more and 40.0 g / 10 min or less, and 25.0 g / 10 min or more and 35 g / 10 min or less. Is more preferable. By setting the MFR of the base resin for the sealing material composition to a high value of 20.0 g / 10 min or more and 40.0 g / 10 min or less, flexibility is given to the sealing material, and the sealing material and glass or the like are transparent. Adhesion with the front substrate can be improved. If the MFR of the base resin for sealing material is less than 20.0 g / 10 min, the viscosity is too high, and a cross-linking reaction occurs during molding due to heat generated during molding, making molding impossible. On the other hand, if the MFR of the base resin for the sealing material exceeds 40.0, the change in the film thickness of the sealing material at the time of producing the module is too large. In addition, it becomes difficult to achieve sufficient heat resistance as a sealing material for a solar cell module that is exposed to a harsh environment for a long time.

  A well-known thing can be used as an organic peroxide for sealing material compositions, It does not specifically limit, For example, a dialkyl peroxide or a peroxy carbonate can be used preferably. Other usable organic peroxides 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) hexyne-3 Dialkyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide Class: t-butyl peroxyacetate, t-butyl peroxyacetate Xyl-2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyoctoate, t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, di-t-butyl peroxyphthalate, 2 , 5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexyne-3, t-butylperoxy-2-ethylhexyl carbonate Examples of oxyesters include ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide.

  As content of the organic peroxide for sealing material compositions, it is content of 0.05 weight part or more and 0.5 weight part or less with respect to a total of 100 weight part of all the resin components of a sealing material composition. Preferably, it is the range of 0.1 weight part or more and 0.2 weight part or less. By adding the organic peroxide for a sealing material composition in this range, sufficient durability can be imparted to the sealing material.

The sealing material composition may further contain other components. For example, other polyolefin resins, or crosslinking aids such as polyfunctional monomers having a carbon-carbon double bond and / or an epoxy group, various fillers, light stabilizers, ultraviolet absorbers, heat stabilizers, etc. And the like. Other polyolefin-based resins preferably have a density of 0.900 g / cm ³ or less, a melting point of less than 80 ° C., are unmodified with silane, and are composed of olefin monomers. Accordingly, other polyolefin resins include low density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA), and the like in addition to LLDPE that satisfies the above conditions. These may be used as an additive resin, for example, and can be used to make other components into a masterbatch. In addition, by including the above-described additive component in an appropriate amount range, it is possible to impart a long-term stable mechanical strength, an effect of preventing yellowing, cracking, and the like to the encapsulant composition.

[Encapsulant]
The encapsulant for the solar cell module of the present invention is obtained by molding the above encapsulant composition comprising the encapsulant master batch of the present invention by a conventionally known method, and a sheet. Or in the form of a film. In addition, the sheet form in this invention means the film form, and there is no difference in both.

  The sealing material composition is formed into a sheet by a conventionally known extrusion molding at a molding temperature of 160 ° C. or higher and 260 ° C. or lower. Thereby, the sealing material which concerns on this invention is obtained by forming the said sealing material composition into a sheet. Limited weak cross-linking without increasing the gel fraction may proceed during the melt extrusion molding, or the film may be formed without being cross-linked and cross-linking may proceed in the subsequent modularization process. .

  Further, the sealing material may be a single layer sheet or a multilayer sheet. In the case of a multilayer sheet, in order to improve adhesion with a glass substrate or the like in a solar cell module, an adhesion reinforcing layer made of a sealing material composition containing a sealing material master batch on the interface side with the glass substrate or the like It only has to be arranged. For this reason, for example, the sealing material may have a two-layer structure and the adhesion reinforcing layer may be disposed only on one layer, or the adhesion reinforcing layer may be disposed on at least one outermost layer with a core layer interposed therebetween. May be.

<Solar cell module>
FIG. 1: is sectional drawing which shows an example of the laminated constitution about the solar cell module 1 which is preferable one Embodiment of the sealing material manufactured using the sealing material masterbatch of this invention. In the solar cell module 1, a transparent front substrate 2, a front sealing material 3, a solar cell element 4, a back sealing material 5, and a back surface protection sheet 6 are sequentially laminated from the light receiving surface side of incident light. The solar cell module 1 uses the sealing material manufactured using the sealing material masterbatch of this invention as the front surface sealing material 3 and / or the back surface sealing material 5.

  For example, the solar cell module 1 is formed by sequentially stacking the members including the transparent front substrate 2, the front sealing material 3, the solar cell element 4, the back sealing material 5, and the back surface protection sheet 6, and then vacuum suction or the like. Then, the above-described members can be manufactured by thermocompression molding as an integral molded body by a molding method such as a lamination method. At this time, the front sealing material 3 made of a single-layer sheet and the glass substrate are laminated, or the adhesion reinforcing layer of the front sealing material 3 made of a multilayer sheet is an example of the transparent front substrate 2. By laminating so as to face the glass substrate, the adhesion between the glass substrate and the sealing material can be improved.

  The solar cell module 1 obtained as described above is characterized by excellent adhesion between a transparent substrate made of glass or the like and a sealing material. That is, since the solar cell module 1 improves the adhesion strength between the transparent substrate made of glass or the like and the sealing material, the solar cell module 1 is exposed to harsh environments such as strong ultraviolet rays, heat rays, and wind and rain. Even so, it has extremely high durability over a long period of time.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

<Manufacture of encapsulant master batch>
The materials described below were mixed in the composition shown in Table 1 (parts by weight), and the resin melted and kneaded at 190 to 210 ° C. was pelletized, and Examples 1 to 2 and Comparative Examples 1 to 4 were used. An encapsulant masterbatch was manufactured. For the above melting and kneading treatment, kneading was performed using a twin-screw extruder (TEX manufactured by Nippon Steel Works), and extrusion was formed.
Base resin for masterbatch (described as “MB base resin” in Table 1): a metallocene copolymer of ethylene and 1-hexene having a density of 0.880 g / cm ³ and an MFR of 3.5 g / 10 min. Linear low density polyethylene.
Silane coupling agent: vinyltrimethoxysilane. (Product name “KBM-1003” manufactured by Shin-Etsu Chemical Co., Ltd.)
Organic peroxide for masterbatch (described as “MB organic peroxide” in Table 1): Dialkyl peroxide (manufactured by Arkema Yoshitomi, trade name “Lupelox 101”). 1 minute half-life temperature 181 ℃
Light resistant stabilizer: HALS. Butanedioic acid 1- [2- (4-hydroxy-2,2,6,6-tetramethylpiperidino) ethyl] (manufactured by BASF, trade name “TINUVIN622”)

<Evaluation Example 1>
About each sealing material masterbatch of an Example and a comparative example, productivity in the case of masterbatch formation was evaluated. Evaluation was performed according to the following criteria.
A: A master batch could be obtained without any problem.
B: Although it gelled a little, masterbatch was completed.
C: Gelled and lost fluidity, and could not be masterbatched.
The evaluation results are shown in Table 1 as “productivity”.

<Manufacture of sealing material>
15 parts by weight of the encapsulant masterbatch of Examples 1 and 2 and Comparative Examples 1 and 2, 85 parts by weight of the base resin for encapsulant composition described below, and the encapsulant composition described below The film forming temperature is such that 5 parts by weight of the organic peroxide for use and the encapsulant composition formed by mixing the other additives described below are melted to a thickness of 400 μm by a conventional T-die method. Film formation was performed at 220 ° C. to obtain the sealing materials of Examples and Comparative Examples. In addition, the sealing material manufactured using the sealing material masterbatch of Example 1 was used as the sealing material of Example 1, and the sealing material manufactured using the masterbatch of Comparative Example 1 was sealed in Comparative Example 1. A material was used. And similarly, it was set as the sealing material of Example 2, and the sealing material of Comparative Examples 2-3 about the sealing material using each sealing material masterbatch. About the sealing material masterbatch of Comparative Examples 3-4, since the unfavorable result was confirmed about the productivity in the above <evaluation example 1> in the manufacturing stage of a masterbatch, manufacture and evaluation of a sealing material were not performed. .
Base resin for encapsulant composition: a metallocene linear low density polyethylene which is a copolymer of ethylene and 1-hexene and has a density of 0.880 g / cm ³ and an MFR of 3.5 g / 10 min.
Organic peroxide for encapsulant composition: Same as organic peroxide for masterbatch.

<Evaluation Example 2>
Each of the sealing materials of Examples and Comparative Examples is closely attached to a glass substrate (white plate float semi-tempered glass JPT3.2 75 mm × 50 mm × 3.2 mm), and is subjected to vacuum heating laminator treatment at 150 ° C. for 7 minutes. It was created. In the above sample for evaluation, the sealing material adhered on the glass substrate was cut to a width of 15 mm, and a vertical peel test (50 mm / min) was performed using a peel tester (Tensilon Universal Tester RTF-1150-H). The initial glass adhesion strength was measured and evaluated. Evaluation was performed according to the following criteria.
A: 30 N / 15 mm or more B: 20 N / 15 mm or more and less than 30 N / 15 mm C: Less than 20 N / 15 mm The evaluation results are shown in Table 1 as “initial adhesion”.
Thereafter, the maintenance rate of the glass adhesion strength after the following dump heat (DH) test with respect to the initial glass adhesion strength was further measured for the sample for evaluation. D. H. The test was based on JIS C8917, and the durability test of the sample for evaluation was performed for 1000 hours under the conditions of 85 ° C. in the test tank and 85% humidity. The test material after the test was subjected to the same test as described above, and the durability adhesion was measured and evaluated. Evaluation was performed according to the following criteria.
A: 20 N / 15 mm or more B: 10 N / 15 mm or more and less than 20 N / 15 mm C: Less than 10 N / 15 mm The evaluation results are shown in Table 1 as “durable adhesion”.

  From the results shown in Table 1, only when the combination of the addition amount of the silane coupling agent and the organic peroxide in the encapsulant masterbatch used by adding to the encapsulant composition is within a predetermined range peculiar to the present application. A sealing material masterbatch containing a silane-modified polyethylene resin and a light-resistant stabilizer can be produced in a preferred embodiment, and a sealing material composition is prepared using such a sealing material masterbatch. In addition, by producing a sealing material using the sealing material composition, the effect of improving the initial adhesion mainly derived from the silane-modified polyethylene resin and the light resistance mainly derived from the light-resistant stabilizer (durable adhesion) ) It can be seen that a sealing material for a solar cell module can be produced under a higher productivity than when using a wider variety of compositions while sufficiently exhibiting the improvement effect. .

DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Transparent front substrate 3 Front sealing material 4 Solar cell element 5 Back surface sealing material 6 Back surface protection sheet

Claims (5)

A method for producing an encapsulant masterbatch for a solar cell module containing a silane-modified polyethylene resin and a light-resistant stabilizer,
A base resin for a masterbatch comprising linear low density polyethylene having a density of 0.900 g / cm ³ or less;
4 parts by weight or more and 6 parts by weight or less of a silane coupling agent with respect to 100 parts by weight of the masterbatch base resin;
0.08 parts by weight or more and 0.2 parts by weight or less of organic peroxide for masterbatch with respect to 100 parts by weight of the base resin for masterbatch,
The presence of the organic peroxide for masterbatch at a temperature of 160 ° C. or higher and 260 ° C. or lower with 0.5 to 5 parts by weight of the light-resistant stabilizer with respect to 100 parts by weight of the base resin for master batch. The manufacturing method of the sealing material masterbatch including the process of kneading below .   The method for producing an encapsulant masterbatch according to claim 1, wherein the light-resistant stabilizer is a hindered amine light-resistant stabilizer.   The manufacturing method of the sealing material masterbatch of Claim 1 or 2 whose said organic peroxide for masterbatch is a dialkyl peroxide or a peroxy carbonate.   The method for producing a sealing material master batch for a solar cell module according to any one of claims 1 to 3, wherein the silane coupling agent is a silane coupling agent having a vinyl group. The sealing material masterbatch for solar cell modules manufactured by the manufacturing method in any one of Claim 1 to 4, the organic peroxide for sealing material compositions, and a density of 0.900 g / cm < ³ > or less The manufacturing method of the sealing material for solar cell modules which melt-extrudes the sealing material composition containing the base resin for sealing material compositions which consists of polyethylene-type resin at 160 degreeC or more and 260 degrees C or less.

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