WO2022065146A1 - Resin composition, method of manufacturing resin composition, solar cell encapsulant, method of manufacturing solar cell encapsulant, solar cell module, resin sheet for laminated glass interlayer film and laminated glass - Google Patents

Abstract

A resin composition that comprises: (A) an ionomer of an ethylene-unsaturated carboxylic acid-based copolymer; (B) at least one kind of lubricant selected from the group consisting of a fatty acid and a fatty acid metal salt; (C) an organic peroxide; and (D) a silane coupling agent. A solar cell encapsulant that comprises a layer formed of the resin composition.

Description

Resin composition, manufacturing method of resin composition, solar cell encapsulant, manufacturing method of solar cell encapsulant, solar cell module, resin sheet for laminated glass interlayer film and laminated glass

The present invention relates to a resin composition, a method for producing a resin composition, a solar cell encapsulant, a method for producing a solar cell encapsulant, a solar cell module, a resin sheet for a laminated glass interlayer film, and a laminated glass.

In recent years, photovoltaic power generation has become widespread as a clean energy source. In photovoltaic power generation, a semiconductor (solar cell element) such as a silicon cell is usually used to convert solar energy into electrical energy. In order to ensure long-term reliability of the solar cell element, the solar cell element is sandwiched between sealing materials to protect the solar cell element and prevent foreign matter from entering the solar cell element and moisture from entering the solar cell element.

Examples of the technology related to the solar cell encapsulant include those described in Patent Documents 1 to 3.

Patent Document 1 describes at least one resin (A) selected from an ethylene-vinyl acetate copolymer and an ethylene-aliphatic unsaturated carboxylic acid copolymer, and the above resin (A) and an ethylene-aliphatic unsaturated compound. A resin sheet containing a thermoplastic resin (B) other than a carboxylic acid ester copolymer, wherein the resin (A) has a melt flow rate value of 0.3 g to 30 g, and the above resin ( A solar cell encapsulating resin sheet including an inner layer made of B) and a surface layer made of the resin (A) laminated on the inner layer is described.

Patent Document 2 describes a resin encapsulating sheet for solar cells that softens and adheres the resin, and the resin encapsulating sheet is an ethylene-vinyl acetate copolymer or an ethylene-aliphatic unsaturated carboxylic acid copolymer. It contains at least one type of ionizing radiation crosslinked resin selected from the group consisting of ethylene-aliphatic unsaturated carboxylic acid ester copolymers, and the gel content is obtained by irradiating the ionized radiation crosslinked resin with ionizing radiation. A resin encapsulating sheet for a solar cell having a ratio of 2 to 65% by mass and a heat shrinkage at 90 ° C. of 15% or less is described.

In Patent Document 3, a front surface protective layer, a solar cell, a back surface protective layer, a polyvinyl acetal resin layer and a second resin layer are laminated, and the content of the plasticizer in 100 parts by mass of polyvinyl acetal in the polyvinyl acetal resin layer is 20 parts by mass or less, the thickness of the polyvinyl acetal resin layer is 600 μm or less, the polyvinyl acetal resin layer is arranged so as to be in contact with at least one surface of the solar cell, and the second resin layer protects the front surface and the back surface. A solar cell module is described that is arranged so as to be in contact with at least one of the layers.

Japanese Unexamined Patent Publication No. 2014-95083 Japanese Unexamined Patent Publication No. 2013-177506 Japanese Unexamined Patent Publication No. 2015-8285

Since the solar cell encapsulant that encloses the solar cell element functions as a protective material for the solar cell element, it is required to have creep resistance that does not easily flow even if the module temperature rises due to sunlight.
Further, in order not to reduce the conversion efficiency of the solar cell, the solar cell encapsulant is required to have high transparency (light transmittance).
Further, the solar cell encapsulant is required to adhere sufficiently strongly to the solar cell element as long as it "seals" the solar cell element.

In recent years, the technical level required for various characteristics of solar cell encapsulants has become higher and higher.
Conventional thermoplastic solar cell encapsulants have room for improvement in terms of good creep resistance, transparency and adhesiveness. In particular, with regard to these three performances, if one attempt is made to improve the performance, the other performance may be deteriorated. For example, when the melting point of the thermoplastic resin is designed to be high and the creep resistance is improved, the transparency may be deteriorated or the adhesiveness may be deteriorated. That is, there is room for improvement in that the three performances of creep resistance, transparency and adhesiveness are improved in a well-balanced manner.

The present invention has been made in view of the above circumstances. One of the objects of the present invention is to obtain a solar cell encapsulant having excellent creep resistance, transparency and adhesiveness. Further, one of the objects of the present invention is to provide a resin composition capable of forming such a solar cell encapsulant.

The present inventors have made extensive studies in order to achieve the above-mentioned problems. As a result, a resin composition containing an ionomer of an ethylene / unsaturated carboxylic acid-based copolymer, at least one lubricant selected from the group consisting of fatty acids and fatty acid metal salts, an organic peroxide, and a silane coupling agent. By manufacturing a solar cell encapsulant using a material, the above three performances could be improved in a well-balanced manner.

The present invention is as follows.

1. 1.
Ionomer (A), an ethylene / unsaturated carboxylic acid-based copolymer, at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts, organic peroxides (C), and silane coupling agents. A resin composition containing (D).
2. 2.
1. 1. The resin composition according to the above.
The metal ions contained in the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer are lithium ion, potassium ion, sodium ion, silver ion, copper ion, calcium ion, magnesium ion, zinc ion, aluminum ion, and barium. A resin composition containing two or more selected from the group consisting of ions, beryllium ions, strontium ions, tin ions, lead ions, iron ions, cobalt ions and nickel ions.
3. 3.
1. 1. Or 2. The resin composition according to the above.
The metal ion contained in the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer contains a first metal ion and a second metal ion different from the first metal ion.
The first metal ion contains at least one metal ion selected from the group consisting of zinc ion, copper ion, iron ion, aluminum ion, silver ion, cobalt ion and nickel ion.
The second metal ion is a resin composition containing at least one metal ion selected from the group consisting of sodium ion, lithium ion, potassium ion and magnesium ion.
4.
3. 3. The resin composition according to the above.
A value obtained by multiplying the value obtained by multiplying the number of moles of the first metal ion by the valence in the ionomer (A) of the ethylene / unsaturated carboxylic acid polymer by the number of moles of the second metal ion by the valence. A resin composition having a ratio of 0.10 or more and 10.0 or less.
5.
1. 1. ~ 4. The resin composition according to any one of the above.
In the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer, when the total number of the constituent units constituting the ethylene / unsaturated carboxylic acid-based copolymer is 100% by mass, it is derived from the unsaturated carboxylic acid. A resin composition having a constituent unit of 5% by mass or more and 35% by mass or less.
6.
1. 1. ~ 5. The resin composition according to any one of the above.
A resin composition having a neutralization degree of ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer of 5% or more and 95% or less.
7.
1. 1. ~ 6. The resin composition according to any one of the above.
A resin composition in which the amount of the lubricant (B) is 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer.
8.
1. 1. ~ 7. The resin composition according to any one of the above.
The lubricant (B) is a resin composition which is a fatty acid having 12 or more and 36 or less carbon atoms or a metal salt of a fatty acid having 12 or more and 36 or less carbon atoms.
9.
1. 1. ~ 8. The resin composition according to any one of the above.
The lubricant (B) contains a metal salt of a fatty acid having 12 or more and 36 or less carbon atoms.
At least a part of the carboxy group of the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer is at least one of the metals constituting the metal salt of the fatty acid having 12 or more and 36 or less carbon atoms contained in the lubricant (B). A resin composition that is neutralized in the part.
10.
1. 1. ~ 9. The resin composition according to any one of the above.
A resin composition in which the silane coupling agent (D) contains a silane coupling agent having a group containing a polymerizable carbon-carbon double bond.
11.
1. 1. ~ 10. The resin composition according to any one of the above.
A resin composition having a 10-hour half-life temperature of the organic peroxide (C) of 100 ° C. or higher.
12.
1. 1. ~ 11. The resin composition according to any one of the above.
A resin composition having a crossover temperature of 150 ° C. or higher measured by the following method.
(Method)
A film of 120 mm × 75 mm × 0.4 mm composed of the resin composition was laminated between glass plates via a release film, and was held in a vacuum laminator at 160 ° C. for 690 seconds, 0.06 MPa (gauge pressure). Press for 15 minutes to obtain a laminated glass. Next, the obtained laminated glass is heat-treated at 165 ° C. for 30 minutes to obtain a laminated glass body. Using the film obtained by removing the glass plate and the release film from the obtained laminated glass as a sample, the shear modulus at a heating rate of 3 ° C./min, a frequency of 1 Hz, and a shear modulus of -60 ° C to 150 ° C in a shear mode is nitrogen. Measure in an atmosphere. The temperature at which the value of the shear storage elastic modulus (G') and the value of the shear loss elastic modulus (G ") are equal is defined as the crossover temperature.
13.
1. 1. ~ 12. The resin composition according to any one of the above.
A resin composition for forming a solar cell encapsulant.
14.
1. 1. ~ 13. The method for producing a resin composition according to any one of the above.
A step of obtaining a mixture by mixing an ionomer (A) of an ethylene / unsaturated carboxylic acid-based copolymer and at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts.
After the step, the step of mixing the mixture, the organic peroxide (C), and the silane coupling agent (D),
A method for producing a resin composition containing.
15.
1. 1. ~ 13. A solar cell encapsulant containing a layer composed of the resin composition according to any one of the above.
16.
1. 1. ~ 13. A method for producing a solar cell encapsulant, which comprises an extrusion molding step of extruding the heated melt of the resin composition according to any one of the above from the T die of an extruder equipped with a T die into a sheet.
17.
16. The method for manufacturing a solar cell encapsulant according to the above.
A method for producing a solar cell encapsulant in which the temperature of the heated melt at the outlet of the T die is 140 ° C. or lower in the extrusion molding step.
18.
With solar cell elements
15. The encapsulating resin layer for encapsulating the solar cell element, which is formed by the solar cell encapsulant according to the above.
A solar cell module equipped with.
19.
1. 1. ~ 12. The resin composition according to any one of the above.
A resin composition used to form an interlayer film of laminated glass.
20.
19. A resin sheet for a laminated glass interlayer film, which comprises a film formed by the resin composition according to 1.
21.
20. The laminated glass interlayer film formed by the resin sheet for the laminated glass interlayer film described in 1.
A laminated glass comprising a transparent plate-like member provided on at least one surface of the laminated glass interlayer film.

INDUSTRIAL APPLICABILITY According to the present invention, a solar cell encapsulant having excellent creep resistance, transparency and adhesiveness is provided. Further, according to the present invention, there is provided a resin composition capable of forming such a solar cell encapsulant.
Incidentally, the resin composition of the present invention is preferably applied to the use for forming a solar cell encapsulant, but can also be applied to other uses, for example, the use for producing an interlayer film of laminated glass.

It is a figure (cross-sectional view) schematically showing an example of the structure of a solar cell module.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the drawings, similar components are designated by the same reference numerals, and description thereof will be omitted as appropriate.
In order to avoid complication, when there are a plurality of the same components in the same drawing, only one of them may be coded and all of them may not be coded.
The drawings are for illustration purposes only. The shape and dimensional ratio of each member in the drawing do not necessarily correspond to the actual article.

The notation "(meth) acrylic" herein represents a concept that includes both acrylic and methacrylic. The same applies to similar notations such as "(meth) acrylate".
In the numerical range described in the present specification stepwise, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in another stepwise description. .. For example, when there is a description of "preferably x1 or more and y1 or less, more preferably x2 or more and y2 or less" for a certain index X, X can be x1 or more and y2 or less, or x2 or more and y1 or less. can.
Further, in the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. For a certain index X, it is preferably described as x or more and y or less in the specification, and when the value of X in the embodiment is z, X may be x or more and z or less, and z or more and y or less. There may be.

<Resin composition>
The resin composition of the present embodiment contains an ionomer (A), which is an ethylene / unsaturated carboxylic acid-based copolymer, at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts, and organic peroxides. (C) and a silane coupling agent (D) are included.

By containing the organic peroxide (C) having a relatively high reactivity, the resin composition of the present embodiment contains the ionomer (A) and the lubricant (B) in heating at the time of sealing the solar cell element. It is considered that the flow of the resin composition is suppressed because the cross-linking reaction proceeds between the molecular chains with the silane coupling agent (D) to form a cross-linked structure. It is presumed that this is related to good creep resistance and adhesiveness.

On the other hand, since the resin composition of the present embodiment contains the lubricant (B), the relaxation of the structure formed by the aggregation of the metal ions in the ionomer (A) is promoted, so that the organic peroxide does not decompose. It can be molded into a sheet-shaped solar cell encapsulant at a relatively low temperature. Thereby, after the resin composition is made into a sheet-shaped solar cell encapsulant and before the solar cell element is encapsulated by the solar cell encapsulant, the organic peroxide (C) is formed. It is presumed that the reaction is suppressed from forming an undesired crosslinked structure.
If the cross-linking reaction proceeds during the molding process, the cross-linking reaction tends to proceed non-uniformly, which tends to be disadvantageous in terms of transparency, sheet appearance, adhesiveness, and sealing of the solar cell element. However, in the present embodiment, since the cross-linking reaction during the molding process is sufficiently suppressed, it is presumed that the transparency, the appearance of the sheet, the adhesiveness, and the sealing of the solar cell element are improved.

The explanation of the components, properties, physical properties, etc. of the resin composition of the present embodiment will be continued.

(Ionomer (A) of ethylene / unsaturated carboxylic acid-based copolymer)
The resin composition of the present embodiment contains an ionomer (A) of an ethylene / unsaturated carboxylic acid-based copolymer. In the following, the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer may be simply referred to as “ionomer (A)”.

The ionomer (A) is typically a resin obtained by neutralizing at least a part of carboxy groups with a metal ion to a polymer obtained by copolymerizing ethylene and at least one unsaturated carboxylic acid. Examples of the ethylene / unsaturated carboxylic acid-based copolymer include a copolymer of ethylene and an unsaturated carboxylic acid, a copolymer of ethylene, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester, and the like. ..

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, and maleic acid. Examples thereof include monoethyl acid. Among these, acrylic acid and / or methacrylic acid is preferable from the viewpoint of productivity, hygiene and the like of the ethylene / unsaturated carboxylic acid-based copolymer.
The unsaturated carboxylic acid may be used alone or in combination of two or more.
Further, an ethylene / unsaturated carboxylic acid-based copolymer containing one or two or more ethylene / unsaturated carboxylic acid-based copolymers and an unsaturated carboxylic acid such as acrylic acid or methacrylic acid as a constituent unit is further added. In addition, it can be an ionomer (A).

Particularly preferable ethylene / unsaturated carboxylic acid-based copolymers are ethylene / (meth) acrylic acid copolymer and ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer.

In the ionomer (A), when the total amount of the structural units constituting the ethylene / unsaturated carboxylic acid-based copolymer is 100% by mass, the structural unit derived from ethylene is preferably 65% by mass or more and 95% by mass or less. It is more preferably 65% by mass or more and 90% by mass or less, and further preferably 65% by mass or more and 85% by mass or less. When the structural unit derived from ethylene is at least the above lower limit value, the heat resistance, mechanical strength, water resistance, processability, etc. of the obtained solar cell encapsulant can be further improved. Further, when the structural unit derived from ethylene is not more than the above upper limit value, the transparency, flexibility, adhesiveness and the like of the obtained solar cell encapsulant can be further improved.

In the ionomer (A), when the total amount of the structural units constituting the ethylene / unsaturated carboxylic acid-based copolymer is 100% by mass, the structural unit derived from the unsaturated carboxylic acid is preferably 5% by mass or more and 35% by mass. % Or less, more preferably 10% by mass or more and 30% by mass or less, still more preferably 15% by mass or more and 25% by mass or less. When the structural unit derived from the unsaturated carboxylic acid is at least the above lower limit value, the transparency, flexibility, adhesiveness, etc. of the obtained solar cell encapsulant can be further improved. Further, when the structural unit derived from the unsaturated carboxylic acid is not more than the above upper limit value, the heat resistance, mechanical strength, water resistance, processability and the like of the obtained solar cell encapsulant can be further improved.

The ionomer (A) is preferably 0% by mass or more and 30% by mass or less, more preferably 0% by mass or more, when the total amount of the constituent units constituting the ethylene / unsaturated carboxylic acid-based copolymer is 100% by mass. It may contain structural units derived from other copolymerizable monomers of 25% by weight or less. Other copolymerizable monomers include unsaturated esters such as vinyl acetate, vinyl esters such as vinyl propionate; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acrylic. Examples thereof include unsaturated carboxylic acid esters such as isobutyl acid, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. When the structural unit derived from the other copolymer monomer is contained within the above range, it is preferable in that the flexibility of the obtained solar cell encapsulant is improved.

Examples of the metal ions constituting the ionomer (A) include lithium ion, potassium ion, sodium ion, silver ion, copper ion, calcium ion, magnesium ion, zinc ion, aluminum ion, barium ion, beryllium ion, and strontium ion. One or more selected from the group consisting of tin ion, lead ion, iron ion, cobalt ion and nickel ion can be mentioned.

Preferably, the ionomer (A) contains two or more metal ions selected from the above group. Although the details are unknown, the inclusion of two or more metal ions in the ionomer (A) causes the cross-linking reaction to proceed appropriately and randomly in the system (suppresses the excessive progress of the cross-linking reaction locally). ) It is presumed that it will be. As a result, the generation of gel can be suppressed, and as a result, the transparency of the solar cell encapsulant is considered to be further enhanced.

More specifically, the composition of the ionomer (A) preferably contains the following first metal ion and a second metal ion different from the first metal ion.
-First metal ion: at least one metal ion selected from the group consisting of zinc ion, copper ion, iron ion, aluminum ion, silver ion, cobalt ion and nickel ion-Second metal ion: sodium ion, lithium ion, At least one metal ion selected from the group consisting of potassium ion and magnesium ion By the way, as a particularly preferable composition of the ionomer (A), an embodiment containing zinc ion as the first metal ion and magnesium ion as the second metal ion is mentioned. be able to.

Since the ionomer (A) contains both the first metal ion and the second metal ion, an unintended cross-linking reaction can be further suppressed, and as a result, the workability of the solar cell encapsulant can be improved, and further. , The generation of gel generated in the solar cell encapsulant sheet can be suppressed, and as a result, the transparency and appearance of the solar cell encapsulant can be further improved.

When the ionomer (A) contains a first metal ion and a second metal ion, the number of moles of the second metal ion to the value obtained by multiplying the number of moles of the first metal ion in the ionomer (A) by the valence is the valence. The ratio of the multiplied values ((number of moles of second metal ion x valence of second metal ion) / (number of moles of first metal ion x valence of first metal ion)) is the obtained solar cell encapsulation. From the viewpoint of improving the balance between transparency and water resistance of the material, it is preferably 0.10 or more, more preferably 0.15 or more, and further preferably 0.20 or more.
Further, in the resin composition (P) according to the present embodiment, the second metal is obtained by multiplying the number of moles of the first metal ion in the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer by the valence. The ratio of the number of moles of ions multiplied by the valence is preferably 10.0 or less from the viewpoint of improving the balance between transparency and water resistance of the obtained solar cell encapsulant. It is more preferably 0 or less, further preferably 4.0 or less, even more preferably 3.0 or less, and particularly preferably 2.5 or less.

The ionomer (A) may be configured to include, for example, ionomer 1 of an ethylene / unsaturated carboxylic acid-based copolymer and ionomer 2 of an ethylene / unsaturated carboxylic acid-based copolymer different from ionomer 1. can. Thereby, by adjusting the mixing ratio of the ethylene / unsaturated carboxylic acid-based copolymer ionomer 1 and the ethylene / unsaturated carboxylic acid-based copolymer ionomer 2, the ethylene / unsaturated carboxylic acid-based copolymer can be adjusted. The ratio of the first metal ion and the second metal ion in the ionomer (A) of the above can be easily adjusted.

The degree of neutralization of the ionomer (A) is not particularly limited, but is preferably 95% or less, more preferably 90% or less, from the viewpoint of improving the flexibility, adhesiveness, processability, etc. of the obtained solar cell encapsulant. It is preferable, 80% or less is further preferable, 50% or less is particularly preferable, and 30% or less is particularly preferable.
The degree of neutralization of the ionomer (A) is not particularly limited, but 5% or more is preferable, and 10% or more is more preferable from the viewpoint of improving the transparency and mechanical strength of the obtained solar cell encapsulant. It is preferable, 15% or more is more preferable, and 20% or more is particularly preferable.
Here, the degree of neutralization of the ionomer (A) refers to the ratio (%) of the carboxy groups neutralized by the metal ion among all the carboxy groups contained in the ethylene / unsaturated carboxylic acid-based copolymer. ..

The ionomer (A) can be configured to include, for example, an ionomer of an ethylene / unsaturated carboxylic acid-based copolymer and an ethylene / unsaturated carboxylic acid-based copolymer containing no metal ion. In this way, the degree of neutralization can be easily adjusted by adjusting the mixing ratio of the ethylene / unsaturated carboxylic acid-based copolymer ionomer and the ethylene / unsaturated carboxylic acid-based copolymer.

The method for producing the ethylene / unsaturated carboxylic acid-based copolymer constituting the ionomer (A) is not particularly limited, and it can be produced by a known method. For example, it can be obtained by radical copolymerizing each polymerization component under high temperature and high pressure. Further, the ionomer (A) can be obtained by reacting an ethylene / unsaturated carboxylic acid-based copolymer with a metal compound.
As the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer, a commercially available one may be used.

As a supplement, the "timing" in which at least a part of the carboxy group of the ethylene / unsaturated carboxylic acid-based copolymer is neutralized with a metal ion to form an ionomer (A) is not particularly limited. The final resin composition may include ionomer (A).
For example, when the final resin composition contains an ionomer (A) containing a first metal ion and a second metal ion, the resin composition is prepared by any of the following methods (i) to (iii). You may. In the examples described later, the resin composition is prepared by the method (ii).
(I) A resin composition is prepared by using the ionomer (A) containing the first metal ion and the second metal ion as it is as a material.
(Ii) First, as a material, an ionomer containing only one of the first metal ion and the second metal ion is prepared. Then, the ionomer and, for example, a fatty acid metal salt exemplified as an example of the lubricant (B) described later are melt-mixed to obtain an ionomer (A) containing two kinds of metal ions. A resin composition is prepared using this ionomer (A).
(Iii) First, an ethylene / unsaturated carboxylic acid-based copolymer containing no metal ion is prepared as a material. Then, the polymer and two suitable metal materials are melt-mixed to obtain an ionomer (A) containing two metal ions. A resin composition is prepared using this ionomer (A).

Further supplementing, in the case of (ii) above, the details are not clear, but since the carboxy group of the ionomer (A) has a lower acid dissociation constant than the carboxy group of the fatty acid metal salt, the metal constituting the fatty acid metal salt. It is believed that at least a portion of the ionomer (A) neutralizes at least a portion of the carboxy group.

In this embodiment, the melt mass flow rate (MFR) of ionomer (A) measured under the condition of 190 ° C. and 2160 g load according to JIS K 7210: 1999 is 0.01 g / 10 minutes or more and 100 g / 10 minutes. It is preferably 0.1 g / 10 minutes or more, and more preferably 80 g / 10 minutes or less. When the MFR is at least the above lower limit value, the workability of the solar cell encapsulant can be further improved. When the MFR is not more than the above upper limit value, the heat resistance and mechanical strength of the obtained solar cell encapsulant can be further improved.

The content of the ionomer (A) in the resin composition is preferably 50.0% by mass or more and 99.9% by mass or less, more preferably 70.0% by mass, when the whole resin composition is 100% by mass. 99.5% by mass or less, more preferably 80.0% by mass or more and 99.5% by mass or less, still more preferably 85.0% by mass or more and 99.0% by mass or less. When the content of ionomer (A) is within the above range, the transparency, creep resistance, interlayer adhesion, insulation property, rigidity, water resistance, and the obtained solar cell module of the obtained solar cell encapsulant can be obtained. The performance balance such as PID resistance can be further improved.

(Glidant (B))
The resin composition of the present embodiment contains at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts. It is considered that the use of the lubricant (B) promotes relaxation of the structure formed by the aggregation of metal ions in the ionomer (A). Therefore, for example, when the resin composition is molded to produce a solar cell encapsulant, the molding process can be performed at a relatively low temperature at which the organic peroxide (C) does not decompose.

As the fatty acid, a fatty acid having 12 or more and 36 or less carbon atoms is preferable, and a fatty acid having 16 or more and 30 or less carbon atoms is more preferable. Specifically, as fatty acids, lauric acid (12 carbon atoms), melissic acid (14 carbon atoms), palmitic acid (16 carbon atoms), stearic acid (18 carbon atoms), oleic acid (18 carbon atoms), behenic acid (18 carbon atoms). 22), erucic acid (22 carbons), montanic acid (28 carbons), melissic acid (30 carbons) and the like. The fatty acid may be only one kind or two or more kinds.

As the fatty acid constituting the fatty acid metal salt, a fatty acid having 12 or more and 36 or less carbon atoms is preferable, and a fatty acid having 16 or more and 30 or less carbon atoms is more preferable. In other words, the fatty acid metal salt is preferably a metal salt of a fatty acid having 12 or more and 36 or less carbon atoms. Specific examples of the fatty acids constituting the fatty acid metal salt include lauric acid (12 carbon atoms), melissic acid (14 carbon atoms), palmitic acid (16 carbon atoms), stearic acid (18 carbon atoms), and oleic acid (carbon number of carbon atoms). 18), behenic acid (22 carbon atoms), oleic acid (22 carbon atoms), montanic acid (28 carbon atoms), melissic acid (30 carbon atoms) and the like. The fatty acid constituting the fatty acid metal salt may be only one kind or two or more kinds.

Examples of the "metal" constituting the fatty acid metal salt include alkali metals, alkaline earth metals, zinc and the like. Among these, magnesium, zinc, and calcium are preferable, and magnesium is more preferable, from the viewpoint of having a relatively low melting point as a fatty acid metal salt. As the metal constituting the fatty acid metal salt, only one kind may be used alone, or two or more kinds may be used in combination.

As the lubricant (B), a fatty acid metal salt is preferable, magnesium stearate, zinc stearate and calcium stearate are more preferable, and magnesium stearate is further preferable.

The resin composition may contain only one kind of lubricant (B), or may contain two or more kinds of lubricant (B).
The amount of the lubricant (B) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and particularly preferably 4 parts by mass or more with respect to 100 parts by mass of the ionomer (A). be. The amount of the lubricant (B) is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, and particularly preferably 15 parts by mass with respect to 100 parts by mass of the ionomer (A). It is as follows.

Incidentally, as described above, at least a part of the carboxy group of the ionomer (A) can be neutralized by at least a part of the metal constituting the fatty acid metal salt. In other words, at least some metal ions of a fatty acid metal salt having a high acid dissociation constant can be incorporated into an ionomer (A) having a low acid dissociation constant. The amount of lubricant (B) described above represents the total amount of lubricant incorporated into the ionomer (A) and the amount of lubricant not (free).

(Organic peroxide (C))
The resin composition of the present embodiment contains an organic peroxide (C). Examples of the organic peroxide (C) include organic peroxides known as radical polymerization initiators.

The 10-hour half-life temperature of the organic peroxide (C) is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, still more preferably 110 ° C. or higher, from the viewpoint of not causing an undesired crosslinking reaction during sheet processing. Further, from the viewpoint that it is desirable to cause a crosslinking reaction in the lamination step, 170 ° C. or lower is preferable, 150 ° C. or lower is more preferable, and 130 ° C. or lower is further preferable.

Examples of the organic peroxide (C) include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, and 2,5-dimethyl-2. , 5-Di- (tert-butylperoxy) hexin-3, bis (tert-butylperoxyisopropyl) benzene, tert-butylcumyl peroxide, 1,1-bis (tert-butylperoxy) -3,3,5- Trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, Examples thereof include tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, tert-butylperoxy-2-ethylhexyl carbonate and the like.

Among these, from the viewpoint of reactivity and handleability, dicumyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di-( tert-butylperoxy) hexine-3, bis (tert-butylperoxyisopropyl) benzene, tert-butylcumyl peroxide, tert-butylperoxyisopropyl carbonate, tert-butylperoxy-2-ethylhexyl carbonate are preferred, 2,5-dimethyl -2,5-di- (tert-butylperoxy) hexane and tert-butylperoxyisopropyl carbonate are more preferable.

The resin composition may contain only one type of organic peroxide (C), or may contain two or more types.
The amount of the organic peroxide (C) is preferably 0.1 part by mass or more, more preferably 0.25 part by mass or more, still more preferably 0.5 part by mass or more with respect to 100 parts by mass of the ionomer (A). Is. The amount of the organic peroxide (C) is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, based on 100 parts by mass of the ionomer (A).

As another viewpoint, the amount of the organic peroxide (C) with respect to 100 parts by mass of the ionomer (A) (unit: parts by mass) and ethylene when the total of the ethylene / unsaturated carboxylic acid-based copolymer is 100% by mass. -A preferable ratio (unit: parts by mass / mass%) to the content (unit: mass%) of the structural unit derived from the unsaturated carboxylic acid in the unsaturated carboxylic acid-based copolymer is preferably 0.01 or more. It is 0.30 or less, more preferably 0.02 or more and 0.15 or less, and further preferably 0.03 or more and 0.10 or less.

By appropriately adjusting the amount of organic peroxide (C), performance such as workability, creep resistance, transparency, and adhesiveness can be further improved.

(Silane Coupling Agent (D))
The resin composition of the present embodiment contains a silane coupling agent (D). The use of the silane coupling agent (D) is effective, for example, from the viewpoint of further improving the interlayer adhesion of the obtained solar cell module.

Examples of the silane coupling agent (D) include (i) a group containing a polymerizable carbon-carbon double bond (vinyl group, (meth) acryloyl group, etc.), an amino group or an epoxy group, and (ii) an alkoxy group. A silane coupling agent having a hydrolyzing group such as the above can be mentioned.
Examples of the silane coupling agent having a polymerizable group carbon-carbon double bond include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-methacryloxy. Propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3-acryloxypropyltriethoxy Examples include silane.

Examples of the silane coupling agent having an amino group include N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N-2- (. Aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- Examples thereof include a hydrochloride of phenyl-3-aminopropyltrimethoxysilane and N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane.

Examples of the silane coupling agent having an epoxy group include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycid. Examples thereof include xipropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane.

The silane coupling agent (D) preferably contains a silane coupling agent having a group containing a polymerizable carbon-carbon double bond, and more preferably contains a silane coupling agent having a (meth) acryloyl group. Particularly preferable specific examples include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane and the like.

The resin composition may contain only one type of silane coupling agent (D), or may contain two or more types.
The amount of the silane coupling agent (D) is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.005% by mass or more and 2% by mass or less, based on 100 parts by mass of the ionomer (A). It is preferably 0.01% by mass or more and 1% by mass or less.

(Other ingredients)
The resin composition of the present embodiment may contain components (other components) other than the above (A) to (D) within a range that does not impair the object of the present invention.

Other components include, for example, plasticizers, antioxidants, ultraviolet absorbers, wavelength converters, antistatic agents, surfactants, colorants, light stabilizers, foaming agents, lubricants, crystal nucleating agents, and crystallization. Accelerators, crystallization retarders, catalyst deactivating agents, heat ray absorbers, heat ray reflecting agents, heat dissipation agents, thermoplastic resins, thermosetting resins, inorganic fillers, organic fillers, impact resistance improvers, slip agents, Crosslinking agent, crosslinking aid, tackifier, processing aid, mold release agent, hydrolysis inhibitor, heat stabilizer, antiblocking agent, antifogging agent, flame retardant, flame retardant aid, light diffusing agent, antibacterial agent , Anti-corrosion agent, dispersant, resin not corresponding to ionomer (A) and the like.

Among other components, a cross-linking aid is preferably used for the purpose of adjusting curability and improving various performances. Examples of the cross-linking aid include oximes such as p-quinonedioxime and p, p'-dibenzoylquinonedioxime; ethylene dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropanetrimethacrylate, cyclohexylmethacrylate, acrylate / zinc oxide. Mixtures, acrylates or methacrylates such as allyl methacrylate; vinyl monomers such as divinylbenzene, vinyltoluene, vinylpyridine; hexamethylene diallyl nadiimide, diallyl itaconate, diallyl phthalate, diallyl isophthalate, diallyl monoglycidyl isocyanurate, triari Allyl compounds such as lucianurate and triallyl isocyanurate; maleimide compounds such as N, N'-m-phenylene bismaleimide, N, N'-(4,4'-methylenediphenylene) dimaleimide, vinylnorbornene, etc. Examples thereof include cyclic non-conjugated dienes such as etylidenenorbornene and dicyclopentadiene.
When a cross-linking aid is used, the amount thereof is preferably 0.1 part by mass or more, more preferably 0.2 part by mass or more, based on 100 parts by mass of the ionomer (A). When a cross-linking aid is used, the amount thereof is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and further preferably 2 parts by mass or less with respect to 100 parts by mass of the ionomer (A).

When the resin composition contains other components, the resin composition may contain only one other component, or may contain two or more other components.

(Physical characteristics)
For example, from the viewpoint of applicability to a solar cell encapsulant, the resin composition of the present embodiment preferably satisfies the physical properties as described below.

Using the resin composition of the present embodiment, the melt mass flow rate (MFR) measured under the condition of 190 ° C. and 2160 g load is preferably 20 g / 10 minutes or less in accordance with JIS K 7210: 1999. It is more preferably 10 g / 10 minutes or less, further preferably 3 g / 10 minutes or less, further preferably 1 g / 10 minutes or less, and particularly preferably 0.5 g / 10 minutes or less. .. When the MFR is not more than the above upper limit value, the creep resistance, mechanical strength, etc. of the obtained solar cell encapsulant can be further improved.

Creep distance The creep distance measured by the method described in Examples described later using the resin composition of the present embodiment is preferably 5.0 mm or less, more preferably 3.0 mm or less, still more preferably 2. It is 0 mm or less, particularly preferably 1.5 mm or less. The lower limit of the creep distance is preferably 0 mm.

-Haze The haze value measured by the method described in Examples described later using the resin composition of the present embodiment is preferably 3.0% or less, more preferably 2.0% or less, still more preferably. It is 1.5% or less, particularly preferably 1.0% or less. The lower limit of the haze value is ideally 0%, but in reality, it is, for example, 0.1%, specifically about 0.3%.

-Total light transmittance The value of the total light transmittance measured by the method described in Examples described later using the resin composition of the present embodiment is preferably 80% or more, more preferably 85% or more. It is more preferably 87% or more, and particularly preferably 90% or more. The upper limit of the total light transmittance is ideally 100%, but in reality, it is, for example, 95%, specifically about 92%.

Adhesive strength to the glass plate Using the resin composition of the present embodiment, the adhesive strength to the glass plate measured by the method described in Examples described later is preferably 10 N / 15 mm or more, preferably 20 N / 15 mm or more. It is more preferable that it is 30 N / 15 mm or more, and it is further preferable that it is 30 N / 15 mm or more. When the adhesive strength to the glass plate is large, the interlayer adhesiveness of the obtained solar cell module can be improved. Basically, the larger the adhesive strength is, the more preferable it is. The adhesive strength depends on the rigidity of the resin, but in reality, if it is 30 N / 15 mm or more, the possibility of delamination or the like occurring is extremely low. Guessed.

-Crossover temperature The crossover temperature measured by the method described in Examples described later using the resin composition of the present embodiment is preferably 140 ° C. or higher, more preferably 150 ° C. or higher. .. It is known that there is a correlation between the crossover temperature and the creep distance, and if the crossover temperature is 140 ° C or higher, the zero shear viscosity at the creep test temperature of 105 ° C is sufficiently high, so that creep can be suppressed. preferable.
There is no particular upper limit to the crossover temperature, but from the viewpoint of realistic composition design, the upper limit is, for example, the thermal decomposition temperature of the resin composition or 240 ° C.

<Manufacturing method of resin composition>
The resin composition of the present embodiment contains an ionomer (A), which is an ethylene / unsaturated carboxylic acid-based copolymer, at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts, and organic peroxides. It can be obtained by mixing (C) with the silane coupling agent (D). For mixing, a commonly used mixing device such as a screw extruder, a roll mixer, or a Bambari mixer can be used.
The mixing may be carried out by blending the four components (A) to (D) at the same time, or may be carried out separately. However, (i) first, the ionomer (A), which is an ethylene / unsaturated carboxylic acid-based copolymer, and at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts are mixed in advance, and (ii). ) Next, a method of mixing the mixture obtained by this mixing, the organic peroxide (C), and the silane coupling agent (D) is preferable.
Ionomer (A), an ethylene / unsaturated carboxylic acid-based copolymer, and at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts are mixed in advance to flow into a resin composition. Gender can be imparted. This makes it possible to suppress the non-uniform progress of the cross-linking reaction by the organic peroxide (C).

<Solar cell encapsulant>
The solar cell encapsulant of the present embodiment includes a layer made of the above-mentioned resin composition.
The solar cell encapsulant of the present embodiment may have a single-layer structure or a multi-layer structure of two or more layers.
More specifically, the solar cell encapsulant of the present embodiment may be (i) a single-layer film composed of a layer composed of the above-mentioned resin composition, or (ii) the above-mentioned resin. It may be a multi-layered film composed of the composition, or (iii) has a layer composed of the above-mentioned resin composition and a layer composed of a resin composition other than the above-mentioned resin composition. It may be a multi-layered film.

When the solar cell encapsulant of the present embodiment has a multi-layer structure, (i) it has a two-layer structure in which two outer layers (hereinafter, also referred to as an adhesive layer) are laminated, and at least one outer layer is the present embodiment. It is a two-layer structure composed of the resin composition of (ii), or a three-layer structure including (ii) an intermediate layer and two outer layers formed on both sides so as to sandwich the intermediate layer. It is preferable that at least one of the intermediate layers has a three-layer structure composed of the resin composition (P) according to the present embodiment.
From the viewpoint of achieving both transparency and adhesiveness, the above-mentioned three-layer structure (ii) is more preferable.

In a multi-layered film having a plurality of layers composed of the resin composition of the present embodiment, the composition of each layer and the type of ionomer contained (for example, the copolymerization ratio of ethylene / unsaturated carboxylic acid-based copolymer, medium). The degree of sum, the type of metal ion, etc.) may be the same or different. Further, the layer made of other than the resin composition (P) according to the present embodiment may or may not contain an organic peroxide.

The thickness of the solar cell encapsulant of the present embodiment is, for example, 0.001 mm or more and 10 mm or less, preferably 0.01 mm or more and 5 mm or less, and more preferably 0.05 mm or more and 2 mm or less. When the thickness of the solar cell encapsulant is 0.001 mm or more, the mechanical strength of the solar cell encapsulant can be improved. Further, when the thickness of the solar cell encapsulant is 10 mm or less, the transparency of the solar cell encapsulant and the processability in the lamination step can be further improved.

When the solar cell encapsulant according to the present embodiment has a multi-layer structure, the layer composed of the resin composition of the present embodiment may be an outer layer or an intermediate layer.

When the solar cell encapsulant of the present embodiment includes an outer layer and an intermediate layer, the thickness of the outer layer is arbitrary, but the thickness a of the outer layer is preferably in the range of 1 μm or more and 500 μm or less, and 10 μm or more and 500 μm. The following range is more preferable, and the range of 20 μm or more and 300 μm or less is particularly preferable. When the thickness a is 1 μm or more, the adhesive strength and workability can be further improved. Further, when the thickness a is 500 μm or less, the transparency is more excellent.

Further, when the solar cell encapsulant of the present embodiment includes an outer layer and an intermediate layer, the thickness of the intermediate layer occupying the total layer thickness may be thick in terms of transparency. Specifically, the thickness b of the intermediate layer can be freely set within a range obtained by subtracting the preferable thickness a of the outer layer from the range of 0.1 mm or more and 10 mm or less, which is the preferable total thickness.

When the solar cell encapsulant of the present embodiment includes an outer layer and an intermediate layer, the thickness ratio (a / b) between the outer layer (thickness a) and the intermediate layer (thickness b) is 1/20 to 5. 1/1 is preferable, more preferably 1/15 to 3/1, still more preferably 1/10 to 3/1. Here, when the solar cell encapsulant of the present embodiment includes two outer layers, the thickness a of the outer layers is the average value of the thicknesses of the two outer layers.
When the thickness ratio (a / b) of the outer layer and the intermediate layer is within the above range, the adhesiveness and transparency are further improved.

<Manufacturing method of solar cell encapsulant>
The method for producing the above-mentioned solar cell encapsulant is not particularly limited, and a conventionally known production method can be adopted as the production method, but it can be preferably produced by the method described below.

As the manufacturing method, for example, a press molding method, an extrusion molding method, a T-die molding method, an injection molding method, a compression molding method, a cast molding method, a calendar molding method, an inflation molding method and the like can be used. Of these, the extrusion molding method is preferable. That is, the solar cell encapsulant of the present embodiment is manufactured including, for example, an extrusion molding step of extruding the heated melt of the above-mentioned resin composition from the T die of an extruder equipped with a T die to form a sheet. It can be obtained by the method.
The processing temperature in the extrusion molding step is not particularly limited, but from the viewpoint of suppressing the crosslinking reaction, the temperature of the heated melt at the outlet of the T die is preferably 200 ° C. or lower, more preferably 160 ° C. or lower, still more preferably 140 ° C. Below, it is preferable to adjust the processing temperature so as to be particularly preferably 130 ° C. or lower, and particularly preferably 120 ° C. or lower. This temperature may be as low as possible as long as extrusion molding is possible, but from the viewpoint of smooth extrusion molding, the temperature of the heated melt at the outlet of the T-die is, for example, 100 ° C. or higher.

<Solar cell module>
FIG. 1 is a cross-sectional view schematically showing the structure of the solar cell module (solar cell module 1) of the present embodiment.
The solar cell module 1 includes, for example, a solar cell element 3 and a sealing resin layer 5 for sealing the solar cell element 3 made of the solar cell encapsulant of the present embodiment. If necessary, the solar cell module 1 may further include a substrate 2 to which sunlight is incident, a protective material 4, and the like (hereinafter, the substrate 2 to which sunlight is incident may be simply referred to as a substrate 2. be).
The solar cell module 1 can be manufactured, for example, by fixing the solar cell element 3 sealed with the solar cell encapsulant of the present embodiment on the substrate 2.

Examples of the solar cell module 1 include various types. For example, a structure such as a substrate / encapsulant / solar cell element / encapsulant / protective material sandwiched between encapsulants from both sides of the solar cell element; a solar cell preformed on the surface of a substrate such as glass. The element is configured as a substrate / solar cell element / sealing material / protective material; a solar cell element formed on the inner peripheral surface of the substrate, for example, an amorphous solar cell element is sputtering on a fluororesin-based sheet or the like. A structure in which a sealing material and a protective material are formed on the material produced in the above;
The protective material 4 is provided on the side opposite to the substrate 2 side of the solar cell module 1, that is, on the lower portion when the substrate 2 on which sunlight is incident is the upper portion of the solar cell module 1. Therefore, the protective material 4 is sometimes referred to as a lower protective material.

Examples of the solar cell element 3 include silicon-based devices such as single crystal silicon, polycrystalline silicon, and amorphous silicon, group III-V such as gallium-arsenide, copper-indium-selenium, copper-indium-gallium-selenium, and cadmium-tellur. Various solar cell elements such as II-VI group compound semiconductor devices can be used.
In the solar cell module 1, a plurality of solar cell elements 3 are usually electrically connected in series via an interconnector 6.

Examples of the substrate 2 constituting the solar cell module 1 include glass, acrylic resin, polycarbonate, polyester, and fluorine-containing resin.
The protective material 4 (lower protective material) is usually a single or multilayer sheet of a metal, various thermoplastic resin films, or the like. Examples of the protective material 4 include single-layer or multi-layer sheets such as metals such as tin, aluminum and stainless steel, inorganic materials such as glass, polyester, inorganic vapor-deposited polyester, fluorine-containing resin and polyolefin. The solar cell encapsulant of the present embodiment exhibits good adhesiveness to these substrates 2 or the protective material 4.

The method for manufacturing the solar cell module 1 is not particularly limited, and examples thereof include the following methods.
First, a plurality of solar cell elements 3 electrically connected using an interconnector 6 are sandwiched between solar cell encapsulants, and these solar cell encapsulants are further sandwiched between a substrate 2 and a protective material 4 to prepare a laminate. do. Next, the laminate is heated and pressurized to bond the members together. By doing so, the solar cell module 1 can be obtained.

<Resin sheet for laminated glass interlayer film and laminated glass>
Up to this point, mainly the resin composition of the present embodiment is used to manufacture a solar cell encapsulant, and the solar cell encapsulant is used to enclose a solar cell element to manufacture a solar cell module. Said to do.
The resin composition of the present embodiment can be applied to various uses other than the sealing of solar cells. For example, it is also possible to manufacture a resin sheet for a laminated glass interlayer using the resin composition of the present embodiment, or to manufacture a laminated glass using the resin sheet for a laminated glass interlayer.

The resin sheet for the laminated glass interlayer film may have a single-layer structure or a multi-layer structure of two or more layers. The specific embodiment of the multi-layer structure can be the same as the above-mentioned mode when the solar cell encapsulant has a multi-layer structure. The thickness of the resin sheet for the laminated glass interlayer film can be about the same as that of the above-mentioned solar cell encapsulant. As for the method for manufacturing the resin sheet for the laminated glass interlayer film, the same manufacturing method as the above-mentioned solar cell encapsulant can be adopted.

A transparent plate provided on at least one surface of the laminated glass interlayer and the laminated glass interlayer by contacting the resin sheet for the laminated glass interlayer and the transparent plate-shaped member to heat and pressurize the laminated glass interlayer. It is possible to manufacture a laminated glass provided with a shaped member. More specifically, a laminated glass can be manufactured by sandwiching a resin sheet for a laminated glass interlayer film between two transparent plate-shaped members and then heating and pressurizing the resin sheet.

The transparent plate-shaped member that can be used is not particularly limited. For example, a commonly used transparent plate glass can be mentioned. Specific examples thereof include float plate glass, polished plate glass, template glass, meshed plate glass, lined plate glass, colored plate glass, heat ray absorbing plate glass, heat ray reflecting plate glass, and inorganic glass such as green glass. It is also possible to use an organic plastic plate such as a polycarbonate plate, a poly (meth) acrylate plate, a polymethyl (meth) acrylate plate, a polystyrene plate, a cyclic polyolefin plate, a polyethylene terephthalate plate, a polyethylene naphthalate plate, or a polyethylene butyrate plate. can.
The transparent plate-shaped member may be subjected to surface treatment such as corona treatment, plasma treatment, and frame treatment.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.

The embodiments of the present invention will be described in detail based on Examples and Comparative Examples. As a reminder, the invention is not limited to examples.

1. 1. Measurement / evaluation method First, the measurement / evaluation method will be described.

[Dynamic Viscoelasticity Measurement / Crossover Temperature]
First, a film having a size of 120 mm × 75 mm × 0.4 mm composed of the resin compositions obtained in Examples and Comparative Examples described later was laminated between glass plates via a release film, and the temperature was 160 ° C. using a vacuum laminator. , Vacuum holding for 690 seconds and pressing at 0.06 MPa (gauge pressure) for 15 minutes to obtain laminated glass.
Next, in order to complete the crosslinking reaction, the obtained laminated glass was heat-treated for 30 minutes in a circulation type high temperature dryer (manufactured by Sanyo Electric Co., Ltd., product name: MOV-212F) set at 165 ° C. As a result, a laminated glass body was obtained (a five-layer structure of a laminated glass body: a glass plate-a release film-a film (crosslinked film) -a release film-a glass plate).
Using the film obtained by removing the glass plate and the release film from the obtained laminated glass body as a sample, ascending with a dynamic viscoelasticity measuring device (MCR302 manufactured by Anton Pearl Co., Ltd.) equipped with a parallel plate having a diameter of 8 mm. The shear modulus at a temperature of 3 ° C./min, a frequency of 1 Hz, and a shear modulus of −60 ° C. to 150 ° C. in a shear mode was measured under a nitrogen atmosphere. The temperature at which the value of the shear storage elastic modulus (G') and the value of the shear loss elastic modulus (G ") are equal is defined as the crossover temperature.

[Creep test]
The film composed of the resin compositions obtained in the examples and comparative examples described below was cut into a size of 180 mm × 160 mm × 0.4 mm. Next, the two obtained films were overlapped, and two float glasses of 180 mm × 180 mm × 3.2 mm were sandwiched by shifting them by 2 cm, and vacuum-held at 150 ° C. for 3 minutes with a vacuum laminator, 0.075 MPa (gauge pressure). Was pressed for 5 minutes to obtain a laminated glass. Further, in order to complete the crosslinking reaction, the laminated glass sample was heat-treated for 30 minutes in a circulation type high temperature dryer (manufactured by Sanyo Electric Co., Ltd., product name: MOV-212F) set at 165 ° C.
Then, one of the obtained laminated glasses was fixed so that the other glass could be freely displaced. Then, after attaching a weight of 400 g to the freely displaceable glass, it was put into a circulation type high temperature dryer (manufactured by Sanyo Electric Co., Ltd., product name: MOV-212F) set at 105 ° C.
The displacement length of the glass after 200 hours of charging was measured. When the displacement length reaches 8 cm or more, the load attached to the test piece comes into contact with the bottom surface of the oven, so measurement is not possible.

[Optical characteristics (haze and total light transmittance)]
The film composed of the resin compositions obtained in the examples and comparative examples described below was cut into a size of 120 mm × 75 mm × 0.4 mm. Next, the obtained film was sandwiched between 120 mm × 75 mm × 3.2 mm white plate glass (haze 0.2% or less, total light transmittance 92% or more), and vacuum-held at 150 ° C. for 3 minutes with a vacuum laminator. Pressing was performed at 1 MPa (gauge pressure) for 5 minutes to obtain a laminated glass. In order to complete the crosslinking reaction, the laminated glass sample was heat-treated for 30 minutes in a circulation type high temperature dryer (manufactured by Sanyo Electric Co., Ltd., product name: MOV-212F) set at 165 ° C.
The haze of the obtained laminated glass was measured according to JIS K 7136: 2000. Further, the total light transmittance of the obtained laminated glass was measured by a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name: haze meter HZ-V3) according to JIS K 7631-1: 1997.

[Adhesiveness]
A film having a size of 120 mm × 75 mm × 0.4 mm composed of the resin compositions obtained in the examples and comparative examples described later was obtained. Next, the obtained film was laminated on the tin surface of a glass plate having a size of 120 mm × 75 mm × 3.9 mm, vacuum-held at 160 ° C. for 690 seconds with a vacuum laminator, and pressed at 0.06 MPa (gauge pressure) for 15 minutes. As a result, the film was adhered to the tin surface of the glass plate. In order to complete the crosslinking reaction, the laminated glass sample was heat-treated for 30 minutes in a circulation type high temperature dryer (manufactured by Sanyo Electric Co., Ltd., product name: MOV-212F) set at 165 ° C.
The bonded film was cut into strips having a width of 15 mm, and then the film was separated from the glass plate at a pulling speed of 100 mm / min at a peel angle of 180 °. The maximum peeling force at this time was calculated as the adhesive strength (N / 15 mm) with respect to the glass plate.

2. 2. Preparation of materials The following materials were prepared.

[Resin (ionomer and other resins)]
Resin-A: Ethylene / methacrylic acid copolymer (ethylene content: 80% by mass, methacrylic acid content: 20% by mass) zinc ionomer (neutralization degree: 40%, MFR (JIS K 7210: 1999) compliant , 190 ℃, measured under the condition of 2160g load): 1.3g / 10 minutes)
Resin-B: Ethylene / methacrylic acid copolymer (ethylene content: 80% by mass, methacrylic acid content: 20% by mass, MFR (measured according to JIS K 7210: 1999, measured at 190 ° C. and 2160 g load)) : 500g / 10 minutes)

[Glidant]
Fatty acid metal salt: Magnesium stearate (trade name: Magnesium stearate G, manufactured by NOF CORPORATION)

[Organic peroxide]
Organic peroxide: (trade name: Luperox101, manufactured by Alchema Yoshitomi Co., Ltd., 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 10-hour half-life temperature = 120 ° C.)

[Crosslinking aid]
Crosslinking aid: TAIC (Triallyl Isocyanurate, manufactured by Wako Pure Chemical Industries, Ltd.)

[Silane coupling agent]
Silane coupling agent-A: 3-methacryloxypropylmethyldiethoxysilane (trade name: KBM502, manufactured by Shin-Etsu Chemical Co., Ltd.)
Silane coupling agent-B: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (trade name: KBM602, manufactured by Shin-Etsu Chemical Co., Ltd.)

3. 3. Manufacture and evaluation of solar cell encapsulant First, resin-A, resin-B and magnesium stearate are melt-kneaded at 160 ° C. and a discharge rate of 10 kg / hour at the blending ratios shown in Table 1 to obtain a kneaded product. rice field. By this kneading, at least a part of the carboxy groups of the resin-A and the resin-B were neutralized with magnesium ions in magnesium stearate.
Next, the obtained kneaded product was blended with Luperox 101, TAIC, a silane coupling agent-A and a silane coupling agent-B in the blending ratios shown in Table 1, and an extruder equipped with a T-die was used. Extrusion molding was performed at a T-die outlet resin temperature of 120 ° C. and a processing speed of 1.3 to 1.9 m / min. As a result, a sheet-shaped resin molded product (solar cell encapsulant) having a thickness of 0.4 mm was obtained.

Using the obtained resin molded product (solar cell encapsulant), the above 1. Was evaluated.

Table 1 summarizes the composition and evaluation results of each composition.
In Table 1, the unit (phr) of the blending amount of magnesium stearate and Luperox 101, TAIC, silane coupling agent-A and silane coupling agent-B was 100 parts by mass in total of resin-A and resin-B. It means the mass part of time.
In Table 1, the "neutralization degree" represents the neutralization degree of the above-mentioned kneaded product of resin-A, resin-B and magnesium stearate.
In Table 1, "MFR" represents the melt mass flow rate measured under the conditions of 190 ° C. and 2160 g load according to JIS K 7210: 1999 of the resin composition.

The resin compositions of Examples 1 and 2 were used, and the performance balance of transparency, creep resistance and interlayer adhesion was excellent. On the other hand, the resin compositions of Comparative Examples 1 to 3 were inferior in the performance balance of transparency, creep resistance and interlayer adhesion.

This application claims priority based on Japanese application Japanese Patent Application No. 2020-160349 filed on September 25, 2020, and incorporates all of its disclosures here.

1 Solar cell module 2 Substrate 3 Solar cell element 4 Protective material 5 Encapsulating resin layer 6 Interconnector

Claims (21)

1. Ionomer (A), an ethylene / unsaturated carboxylic acid-based copolymer, at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts, organic peroxides (C), and silane coupling agents. A resin composition containing (D).
2. The resin composition according to claim 1.
   The metal ions contained in the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer are lithium ion, potassium ion, sodium ion, silver ion, copper ion, calcium ion, magnesium ion, zinc ion, aluminum ion, and barium. A resin composition containing two or more selected from the group consisting of ions, beryllium ions, strontium ions, tin ions, lead ions, iron ions, cobalt ions and nickel ions.
3. The resin composition according to claim 1 or 2.
   The metal ion contained in the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer contains a first metal ion and a second metal ion different from the first metal ion.
   The first metal ion contains at least one metal ion selected from the group consisting of zinc ion, copper ion, iron ion, aluminum ion, silver ion, cobalt ion and nickel ion.
   The second metal ion is a resin composition containing at least one metal ion selected from the group consisting of sodium ion, lithium ion, potassium ion and magnesium ion.
4. The resin composition according to claim 3.
   A value obtained by multiplying the value obtained by multiplying the number of moles of the first metal ion by the valence in the ionomer (A) of the ethylene / unsaturated carboxylic acid polymer by the number of moles of the second metal ion by the valence. A resin composition having a ratio of 0.10 or more and 10.0 or less.
5. The resin composition according to any one of claims 1 to 4.
   In the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer, when the total number of the constituent units constituting the ethylene / unsaturated carboxylic acid-based copolymer is 100% by mass, it is derived from the unsaturated carboxylic acid. A resin composition having a constituent unit of 5% by mass or more and 35% by mass or less.
6. The resin composition according to any one of claims 1 to 5.
   A resin composition having a neutralization degree of ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer of 5% or more and 95% or less.
7. The resin composition according to any one of claims 1 to 6.
   A resin composition in which the amount of the lubricant (B) is 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer.
8. The resin composition according to any one of claims 1 to 7.
   The lubricant (B) is a resin composition which is a fatty acid having 12 or more and 36 or less carbon atoms or a metal salt of a fatty acid having 12 or more and 36 or less carbon atoms.
9. The resin composition according to any one of claims 1 to 8.
   The lubricant (B) contains a metal salt of a fatty acid having 12 or more and 36 or less carbon atoms.
   At least a part of the carboxy group of the ionomer (A) of the ethylene / unsaturated carboxylic acid-based copolymer is at least one of the metals constituting the metal salt of the fatty acid having 12 or more and 36 or less carbon atoms contained in the lubricant (B). A resin composition that is neutralized in the part.
10. The resin composition according to any one of claims 1 to 9.
    A resin composition in which the silane coupling agent (D) contains a silane coupling agent having a group containing a polymerizable carbon-carbon double bond.
11. The resin composition according to any one of claims 1 to 10.
    A resin composition having a 10-hour half-life temperature of the organic peroxide (C) of 100 ° C. or higher.
12. The resin composition according to any one of claims 1 to 11.
    A resin composition having a crossover temperature of 150 ° C. or higher measured by the following method.
    (Method)
    A film of 120 mm × 75 mm × 0.4 mm composed of the resin composition was laminated between glass plates via a release film, and was held in a vacuum laminator at 160 ° C. for 690 seconds, 0.06 MPa (gauge pressure). Press for 15 minutes to obtain a laminated glass. Next, the obtained laminated glass is heat-treated at 165 ° C. for 30 minutes to obtain a laminated glass body. Using the film obtained by removing the glass plate and the release film from the obtained laminated glass as a sample, the shear modulus at a heating rate of 3 ° C./min, a frequency of 1 Hz, and a shear modulus of -60 ° C to 150 ° C in a shear mode is nitrogen. Measure in an atmosphere. The temperature at which the value of the shear storage elastic modulus (G') and the value of the shear loss elastic modulus (G ") are equal is defined as the crossover temperature.
13. The resin composition according to any one of claims 1 to 12.
    A resin composition for forming a solar cell encapsulant.
14. The method for producing a resin composition according to any one of claims 1 to 13.
    A step of obtaining a mixture by mixing an ionomer (A) of an ethylene / unsaturated carboxylic acid-based copolymer and at least one lubricant (B) selected from the group consisting of fatty acids and fatty acid metal salts.
    After the step, the step of mixing the mixture, the organic peroxide (C), and the silane coupling agent (D),
    A method for producing a resin composition containing.
15. A solar cell encapsulant containing a layer composed of the resin composition according to any one of claims 1 to 13.
16. Solar cell encapsulation including an extrusion molding step of extruding the heated melt of the resin composition according to any one of claims 1 to 13 from the T die of an extruder equipped with a T die to form a sheet. Material manufacturing method.
17. The method for manufacturing a solar cell encapsulant according to claim 16.
    A method for producing a solar cell encapsulant in which the temperature of the heated melt at the outlet of the T die is 140 ° C. or lower in the extrusion molding step.
18. With solar cell elements
    A sealing resin layer for encapsulating the solar cell element, which is formed by the solar cell encapsulant according to claim 15.
    A solar cell module equipped with.
19. The resin composition according to any one of claims 1 to 12.
    A resin composition used to form an interlayer film of laminated glass.
20. A resin sheet for a laminated glass interlayer film, which comprises a film formed by the resin composition according to claim 19.
21. The laminated glass interlayer film formed by the resin sheet for the laminated glass interlayer film according to claim 20 and the laminated glass interlayer film,
    A laminated glass comprising a transparent plate-like member provided on at least one surface of the laminated glass interlayer film.

Images