TWI731941B - Ion capture agent for solar cell, and solar cell encapsulant composition containing it, and solar cell module - Google Patents

Abstract

The ion trapping agent for solar cells of the present invention contains at least a part of (A) ion exchange group substituted with at least one ion (a1) selected from lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion and calcium ion α-zirconium phosphate, and (B) α-titanium phosphate substituted with at least one ion (b1) selected from the group consisting of lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion, and calcium ion at least a part of the ion exchange group At least one of them.

Description

Ion scavenger for solar cells, encapsulant composition for solar cells and solar cell modules containing the same

^{The present invention relates to an ion capture agent for solar cells that can highly selectively adsorb Na +} ions that are the cause of PID (Potential Induced Degradation) of solar cells, and can provide solar cells with excellent PID resistance, and containing them Encapsulant composition for solar cells and solar cell modules.

Based on the increased awareness of environmental issues, we use solar cells that are clean energy sources. Generally speaking, a solar cell is a composite with a plurality of solar cell modules. This solar cell module has a transparent protective member on the front side, a layer encapsulating the solar cell elements, and a backside protective member (back sheet). structure.

In recent years, a large number of crystalline silicon solar cell modules have been installed on a large building area to construct a large-scale solar power generation system called "mega-solar", which is a solar power generation system for electric power business. Increase rapidly. For this large-scale solar power generation system, in order to simplify the wiring project between solar cell modules, reduce the number of wiring or junction boxes to reduce costs, most of them are connected in series with multiple solar cell modules. Group, the maximum system voltage is designed to be as high as about 600V to 1000V. However, in this kind of high system voltage crystalline silicon solar power generation system, the crystalline silicon solar cell module sometimes suffers from the so-called rapid degradation of PID characteristics.

Regarding the PID phenomenon of this crystalline silicon solar cell module, its cause or mechanism has not yet been fully elucidated. However, it has been reported that the PID phenomenon is more likely to occur and deteriorate when a higher system voltage is applied to the solar cell module, and it is in a high temperature or high humidity state. Moreover, by applying a high voltage in the opposite direction to the solar cell module, The characteristics can be restored.

Hereinafter, the mechanism of the PID phenomenon in a crystalline silicon solar cell module using a crystalline silicon solar cell unit composed of a general P-type wafer will be described. The surface of the crystalline silicon solar cell module is usually covered with a cover glass made of soda lime glass. Here, when moisture is present on the surface of the cover glass, sodium ions (Na ⁺ ions), which are metal ions, are generated from the soda lime glass. The cover glass of the crystalline silicon solar cell module is supported by a metal frame, which is connected to the ground to form a ground potential.

In this state, when a negative system voltage is applied to the internal wiring of the crystalline silicon solar cell module, a large potential difference occurs between the inside and outside of the crystalline silicon solar cell module. ^{The Na +} ions (metal ions) on the surface of the cover glass move in the cover glass or the encapsulation filling resin by this potential difference, and reach the surface of the crystalline silicon solar cell unit. Under the conditions of high temperature and high humidity, the volume resistivity of the cover glass or the encapsulating resin decreases, the leakage current increases, and the Na ⁺ ions (metal ions) are easier to move.

Generally speaking, the light incident side of the crystalline silicon solar cell unit The surface of the doped layer (N-type) is covered with an insulating passivation film. The passivation film is polarized due to the adhesion of charged ions. As a result, a polarity inversion region (P-type) is formed near the interface between the doped layer (N-type) and the passivation layer on the light-incident side of the crystalline silicon solar cell unit, which hinders the movement of light-generated carriers and degrades the cell characteristics. .

As a method of preventing the occurrence of this PID phenomenon, several methods have been proposed so far. For example, as a countermeasure for solar power generation systems, it is known to use inverters with insulating transformers, ground the negative pole of the inverter input, etc., to prevent the solar cell module from forming a negative voltage relative to the outside. Potential method. However, in recent years, in order to achieve high efficiency of inverters or reduce costs, and continue to promote transformerless, it is increasingly difficult to respond to such systems.

On the other hand, as a countermeasure for solar cell modules, Japanese Patent Application Laid-Open No. 2011-77172 discloses a structure in which solar cell modules are encapsulated with EVA to prevent water vapor from entering. To the inside of the solar cell module, and an ion polymer resin layer is provided on the side of the EVA resin opposite to the solar cell unit.

Moreover, although it is not aimed directly at improving the PID phenomenon, there is a discussion on increasing the volume resistivity of the packaging material. Japanese Patent Laid-Open No. 11-54766 discloses a solar cell encapsulating material, in which a silane coupling agent with a carbon number of 4 or less of the functional group directly bonded to the silicon atom is based on 100 parts by weight of ethylene·vinyl acetate The copolymer is added at a ratio of 5 parts by weight or less. Also, Japanese Patent Application Publication No. 2013-64115 discloses a An encapsulating material for solar cells, which uses structural units derived from ethylene and structural units derived from unsaturated esters, and the sum of structural units derived from ethylene and structural units derived from unsaturated esters is set to 100 It is obtained by 100 parts by mass of an ethylene-unsaturated ester copolymer containing 0.001 to 5 parts by mass of metakaolin in an amount of 20 to 35% by mass of the structural unit derived from the unsaturated ester.

Furthermore, Japanese Patent Application Laid-Open No. 2015-138805 discloses a resin composition for solar cell encapsulating materials, which contains an ethylene copolymer, and an oxide selected from the group consisting of pentavalent metal, hexavalent metal oxide, and heptavalent metal. It is an inorganic ion trapping agent composed of oxides and metal phosphates.

Although Japanese Patent Laid-Open No. 2015-138805 describes the use of zirconium phosphate (an ion exchanger for inorganic use) as an example of metal phosphate, although this ion trapping agent can trap Na ⁺ ions, it is not sufficient; moreover, due to ions The exchange releases H ⁺ ions. Therefore, depending on the structure, there is a problem that the pH drops, which adversely affects the encapsulating resin, or accelerates the corrosion of the constituent members of the solar cell element such as the electrode.

The object of the present invention is to provide an ion scavenger for solar cells ^{that can adsorb Na + ions that are the cause of the PID of solar cells with high selectivity.}

Furthermore, another object of the present invention is to provide a solar cell encapsulant composition that can suppress the reduction in power caused by PID or the corrosion of the constituent members of the solar cell element such as electrodes, and a long-life solar cell mold group.

The inventors of the present case found that at least a part of the ion exchange group is substituted with at least one ion selected from lithium ion, potassium ion, rubidium ion, cesium ion, magnesium ion, and calcium ion. The ion scavenger for solar cells in which at least one part of α-titanium phosphate is substituted with at least one ion selected from lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion, and calcium ion, can be selectively adsorbed ^{The Na +} ions caused by PID have finally completed the present invention.

1. An ion trapping agent for solar cells, characterized in that at least a part of the ion exchange group containing (A) is passed through at least one ion selected from the group consisting of lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion, and calcium ion (a1 ) Substituted α-zirconium phosphate, and, (B) α in which at least a part of the ion exchange group is substituted with at least one ion (b1) selected from the group consisting of lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion and calcium ion -At least one of titanium phosphate.

2. The ion trapping agent for solar cells according to 1 above, wherein the above component (A) is the α-zirconium phosphate substituted with the above ion (a1) in the total ion exchange capacity of 0.1 to 6.7 meq/g.

3. The ion trapping agent for solar cells according to 1 or 2, wherein the α-zirconium phosphate before being substituted by the ion (a1) is a compound represented by the following formula (1): Zr _1-x Hf _x H _a ( PO ₄ ) _b ‧mH ₂ O (1) (where 0≦x≦0.2, 2<b≦2.1, a is a number that satisfies 3b-a=4, and 0≦m≦2).

4. The ion trapping agent for solar cells according to any one of 1 to 3 above, wherein the component (B) is an α-titanium phosphate substituted with the ion (b1) in the total ion exchange capacity of 0.1 to 7.0 meq/g.

5. The ion trapping agent for solar cells according to any one of 1 to 4 above, wherein the α-titanium phosphate before being substituted by the ion (b1) is a compound represented by the following formula (2): TiH _s (PO ₄ ) _t ‧nH ₂ O (2) (where 2<t≦2.1, s is a number satisfying 3t-s=4, and 0≦n≦2).

6. An encapsulant composition for solar cells, characterized by containing the ion scavenger for solar cells according to any one of 1 to 5 above, and a resin.

7. The solar cell encapsulant composition according to 6 above, wherein the resin system contains ethylene·vinyl acetate copolymer resin.

8. A solar cell module characterized by having a front-side transparent protection member, a back-side protection member, solar cell elements, and between the front-side transparent protection member and the back-side protection member, the use of 6 or 7 above The encapsulant composition for solar cells is an encapsulant layer formed by encapsulating the solar cell element.

The ion trapping agent for solar cells of the present invention can adsorb Na ⁺ ions that are the cause of the PID of solar cells with high selectivity, and is not easy to release H ⁺ ions. Therefore, the power reduction caused by PID can be suppressed. In addition, the encapsulant composition for solar cells of the present invention can suppress corrosion of constituent members of solar cell elements such as electrodes, and can provide a solar cell module with a long life.

10‧‧‧Solar battery module

11‧‧‧Solar cell components

13‧‧‧Encapsulation layer

15‧‧‧Transparent protective member on the surface side

17‧‧‧Back side protection member

19‧‧‧Internal connection line

Figure 1 is a schematic cross-sectional view showing the solar cell module of the present invention.

[The form of implementing the invention]

Hereinafter, the present invention will be described in detail.

1. Ion trapping agent for solar cells

The ion trapping agent for solar cells of the present invention contains at least a part of (A) ion exchange group substituted with at least one ion (a1) selected from lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion and calcium ion α-Zirconium phosphate (hereinafter referred to as "ion capture agent for solar cells (A)"), and (B) at least a part of the ion exchange group is selected from lithium ions, potassium ions, cesium ions, rubidium ions, magnesium ions, and calcium ions. At least one of α-titanium phosphate substituted with at least one ion (b1) of ions (hereinafter referred to as "ion capture agent for solar cells (B)"). The ion exchange group is usually a proton.

In the present invention, for example, the solar cell element 11 constituting the solar cell module 10 shown in FIG. 1, the encapsulation layer 13 that encapsulates the solar cell element 11 with resin, the front side transparent protective member 15 and the back side are protected At least one of the encapsulating layer 13 containing resin and the back side protection member 17 in the member 17 contains an ion scavenger for solar cells, which can extend the life of the solar cells. That is, since the ion trapping agent for solar cells of the present invention does not release protons (H ⁺ ), it is possible to suppress decomposition or deterioration of components of the solar cell, and it is also possible to suppress reduction in power.

The α-zirconium phosphate before the substitution of the above ion (a1) and the α-titanium phosphate before the substitution of the above ion (b1) have a large number of OH groups in the layer. The structure replaced by lithium ions, potassium ions, rubidium ions, cesium ions, magnesium ions or calcium ions will not release H ⁺ ions and can selectively adsorb Na ⁺ ions.

Since the ion scavenger for solar cells of the present invention is neutral, when added to the electrolyte, the pH will not be greatly changed. When the encapsulation layer 13 contains an alkaline or acidic substance, the resin may decompose due to a change in pH. For example, when the resin contains ethylene-vinyl acetate copolymer resin, it is easy to generate acetic acid, etc., which will cause the deterioration of the solar cell; if it is an encapsulation layer containing the ion scavenger for solar cells of the present invention, such defects will not occur. situation.

In addition, since the ion scavenger for solar cells of the present invention is an inorganic compound, it is excellent in thermal stability and stability in solvents. Therefore, when it is contained in the constituent members of the solar cell, it is stable even in the state of applying electric charge.

1-1. Ion scavenger for solar cells (A)

The ion scavenger (A) for solar cells of the present invention is an ion (a1) substituted product of α-zirconium phosphate as described above.

The above-mentioned α-zirconium phosphate is a compound represented by the following formula (1): Zr _1-x Hf _x H _a (PO ₄ ) _b ‧mH ₂ O (1) (where 0≦x≦0.2, 2<b ≦2.1, a is a number satisfying 3b-a=4, and 0≦m≦2).

Since the ion exchange group of the above-mentioned α-zirconium phosphate is usually a proton, a part or all of the proton can be replaced by the ion (a1) to form the ion trap (A) for solar cells of the present invention. The ion (a1) is at least one selected from the group consisting of lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion, and calcium ion, and ^{from the viewpoint of good capture of Na +} ions, it is preferably derived from a monovalent alkali metal element Ion (lithium ion, potassium ion, rubidium ion or cesium ion).

In the ion trapping agent (A) for solar cells of the present invention, the amount of ion (a1) used for substitution is preferably 0.1 to 6.7 meq/g, more preferably 1.0 to 6.7 meq/g. In addition, from the ^{viewpoint of Na +} ion adsorption capacity, it is more preferably 3.5 to 6.7 meq/g.

^{From the viewpoint of the capturing properties of Na +} ions, x in the above formula (1) is preferably 0≦x≦0.1, and more preferably 0≦x≦0.02. In addition, if Hf is included, it is preferably 0.005≦x≦0.1, and more preferably 0.005≦x≦0.02. When x>0.2, although the ion exchange performance of the ion (a1) can be improved, because of the presence of radioactive isotopes, when the component parts of the solar cell include electronic parts, it will cause adverse effects.

The method of manufacturing the ion scavenger (A) for solar cells of this invention is not specifically limited. For example, to produce α-zirconium phosphate substituted with lithium ions, a method of adding α-zirconium phosphate to a lithium hydroxide (LiOH) aqueous solution and stirring for a certain period of time, followed by filtration, washing, and drying can be used. The concentration of the LiOH aqueous solution is not particularly limited. When the concentration is high, the alkalinity of the reaction solution becomes high and part of the α-zirconium phosphate is eluted. Therefore, it is preferably 1 mol/L or less, and more preferably 0.1 mol/L or less.

To produce α-zirconium phosphate substituted with potassium ions, the same ion exchange method as described above can also be applied.

To produce α-zirconium phosphate substituted with magnesium or calcium ions, the hydroxide of magnesium or calcium is hardly soluble in water, so it can be temporarily substituted with alkali metal ions such as potassium and then replaced with an aqueous solution of magnesium chloride, etc. . In addition, for example, α-zirconium phosphate may be added to the magnesium acetate aqueous solution to perform the same operation.

1-2. Ion scavenger for solar cells (B)

The ion scavenger (B) for solar cells of the present invention is the ion (b1) substitution product of α-titanium phosphate as described above.

The above-mentioned α-titanium phosphate is a compound represented by the following formula (2): TiH _s (PO ₄ ) _t ‧nH ₂ O (2) (where, 2<t≦2.1, and s satisfies 3t-s=4 Number, and 0≦n≦2).

Since the ion exchange group of α-titanium phosphate is usually protons, part or all of the protons can be replaced by ions (b1) to form the ion trapping agent (B) for solar cells of the present invention. The ion (b1) is at least one selected from the group consisting of lithium ion, potassium ion, cesium ion, rubidium ion, magnesium ion, and calcium ion, and based on ^{the good capturing ability of Na +} ion, it is preferably derived from a monovalent alkali metal element Ion (lithium ion, potassium ion, rubidium ion or cesium ion).

In the ion trapping agent (B) for solar cells of the present invention, the amount of ion (b1) used for substitution is preferably 0.1 to 7.0 meq/g, more preferably 1.0 to 7.0 meq/g. In addition, from the ^{viewpoint of Na +} ion adsorption capacity, it is more preferably 3.5 to 7.0 meq/g.

The method for producing the ion trapping agent (B) for solar cells of the present invention is not particularly limited, and the same method as the method for producing the ion trapping agent (A) for solar cells can be adopted.

The ion trapping agent for solar cells of the present invention usually has a layered structure, and the upper limit of the median particle size is preferably 5.0 μm, more preferably 3.0 μm, and even more preferably 2.0 μm; the lower limit is usually 0.2 μm, preferably 0.5 μm. What is necessary is just to select a preferable particle diameter according to the kind of the structural member of the ion scavenger for solar cells to which this invention is applied.

The water content of the ion scavenger for solar cells of the present invention is preferably 10% by mass or less, more preferably 5% by mass or less. Permeable moisture content is 10% by mass or less, and it can suppress water when making components that constitute solar cells. The gas generation caused by electrolysis can be separated, which can suppress battery defects. In addition, the moisture content can be measured by Karl Fischer's method.

When the water content of the ion scavenger for solar cells is 10% by mass or less, it is not particularly limited, and the drying method of the powder to be used can usually be applied. For example, a method of heating at 100°C to 300°C for about 6 to 24 hours under atmospheric pressure or reduced pressure.

2. Encapsulant composition for solar cells

The encapsulant composition for solar cells of the present invention is characterized by containing the ion scavenger for solar cells of the present invention and resin. The encapsulant composition for solar cells of the present invention may contain other components such as a crosslinking agent, a crosslinking aid, an adhesive improver, an ultraviolet absorber, a light stabilizer, and an antioxidant described later.

The encapsulant composition for solar cells of the present invention is suitable for forming the encapsulant layer 13 between the front side transparent protective member 15 and the back side protective member 17 constituting the solar cell module 10 shown in FIG. 1, for example.

Examples of the resin contained in the encapsulant composition for solar cells of the present invention include ethylene·vinyl acetate copolymer resin; polyolefin resins such as polyethylene and polypropylene; ionomer resin; ethylene·methacrylic acid copolymer Materials; ethylene‧methacrylate copolymer; ethylene‧acrylic acid copolymer; ethylene‧acrylate copolymer; polyvinyl fluoride resin; polyvinyl chloride resin, etc. Among these, ethylene-vinyl acetate copolymer resin is particularly preferred in terms of forming an encapsulating layer with excellent transparency.

The above-mentioned ethylene‧vinyl acetate copolymer resin is not particularly limited It is determined that when manufacturing solar cell modules, for example, after the vacuum heating lamination step, the heat resistance of 100°C to 150°C can be smoothly obtained due to the high degree of crosslinking caused by the high gel fraction, preferably The content of the structural unit derived from vinyl acetate is preferably 20-40% by mass, more preferably 25-35% by mass, and still more preferably 28-33% by mass ethylene-vinyl acetate copolymer resin.

The melt mass flow rate (MFR) of the above-mentioned ethylene·vinyl acetate copolymer resin is preferably 1g-40g/10 minutes, more preferably 15g-40g/ in accordance with the method (190°C) of JIS K 7210 10 points. In addition, the Vicat softening point is preferably 30°C to 40°C in accordance with JIS K 7206.

In the solar cell encapsulant composition of the present invention, the content ratio of the ion scavenger for solar cells is based on the transparency of the encapsulation layer and the ^{capturing properties of Na +} ions in the encapsulation layer, and the content of the resin is set to 100 In parts by mass, it is preferably 0.01 to 1.0 part by mass, more preferably 0.05 to 0.5 part by mass. In addition, the median particle size of the ion scavenger for solar cells is preferably 0.5 to 5.0 μm, and more preferably 0.7 to 2.0 μm based on the power generation efficiency of the solar cell.

The encapsulant composition system for solar cells of the present invention is as described above, and may also contain other components.

As the crosslinking agent, organic peroxides, azo compounds, tin compounds, etc. can be used. These can be used alone or in combination of two or more kinds.

Examples of organic peroxides include hydroperoxides such as dicumyl hydroperoxide and 2,5-dimethyl-2,5-di(hydroperoxy)hexane; peroxides Di(tertiary butyl), tertiary butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tertiary butyl peroxide) hexane , 2,5-Dimethyl-2,5-bis (tertiary butyl peroxide) hexyne-3 and other dialkyl peroxides; bis-3,5,5-trimethyl hexyl peroxide Diyl peroxide, octyl peroxide, benzyl peroxide, o-methylbenzyl peroxide, 2,4-dichlorobenzyl peroxide, etc.; tertiary butyl peroxide , Tertiary butyl peroxide-2-ethylhexanoate, tertiary butyl peroxide, tertiary butyl peroxide, tertiary butyl peroxide, tertiary butyl isopropyl carbonate, peroxide Oxidized tertiary butyl benzoate, di-peroxy tertiary butyl phthalate, 2,5-dimethyl-2,5-bis(benzyl peroxide) hexane, 2, Peroxy esters such as 5-dimethyl-2,5-bis(benzyl peroxide)hexyne-3, tertiary butyl peroxide-2-ethylhexyl carbonate, etc.; methyl ethyl ketone peroxide, peroxide Ketone peroxides such as cyclohexanone.

Examples of the azo compound include azobisisobutyronitrile, azobis(2,4-dimethylvaleronitrile), and the like.

Moreover, as a tin compound, dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin dioctoate, dioctyl tin dilaurate, etc. are mentioned.

When the encapsulant composition for solar cells of the present invention contains a cross-linking agent, the content of the resin is preferably 0.01 to 2.0 parts by mass, and more preferably 0.05 to 1.5 parts by mass when the content of the resin is set to 100 parts by mass. Copies.

The cross-linking auxiliary agent is used to promote the cross-linking reaction of the cross-linking agent, preferably a multifunctional monomer having at least one of a carbon atom-carbon double bond and an epoxy group, more preferably an allyl group, Methacrylic acid, acrylic acid Polyfunctional monomers such as a group and a vinyl group, and specific examples thereof include polyallyl compounds, poly(meth)acryloxy compounds, epoxy compounds, and the like. These can be used alone or in combination of two or more kinds.

Examples of polyallyl compounds include triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl fumarate, and di-maleic acid. Allyl esters and so on.

Examples of poly(meth)acrylic oxy compounds include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, etc.

In addition, examples of epoxy compounds include glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4- Butylene glycol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, trimethylolpropane polyglycidyl ether, etc.

When the encapsulant composition for solar cells of the present invention contains a cross-linking aid, in terms of the content ratio, when the content of the above-mentioned resin is set to 100 parts by mass, it is preferably 0.01 to 3.0 parts by mass, more preferably 0.05 to 2.0 Mass parts.

The adhesive modifier is preferably a silane compound having a polymerizable unsaturated bond such as a methacryl group, an acryl group, and a vinyl group, or a hydrolyzable group such as an alkoxy group, and a well-known silane couple can be used. mixture.

As the above-mentioned silane coupling agent, vinyl trichlorosilane, vinyl ginseng (β-methoxyethoxy) silane, vinyl triethoxy silane, ethyl Alkenyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane, β-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, γ-glycidoxypropyl methyl Diethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, γ- Aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, etc.

When the encapsulant composition for solar cells of the present invention contains an adhesive improver, the content of the resin is preferably 0.01 to 3.0 parts by mass when the content of the resin is 100 parts by mass.

系化合物、水楊酸酯系化合物等。此等可單獨使用，亦可組合使用2種以上。 Examples of ultraviolet absorbers include benzophenone-based compounds, benzotriazole-based compounds, three

Series compounds, salicylate series compounds, etc. These can be used alone or in combination of two or more kinds.

-2-基]-5-(辛氧基)酚、2-(4,6-二苯基-1,3,5-三

-2-基)-5-(己氧基)酚、水楊酸苯酯、水楊酸對辛基苯酯等。 Examples of the ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2 '- carboxy benzophenone, 2-hydroxy-4-octyloxy Benzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone Ketone, 2-hydroxy-4-methoxy-5-sulfonic benzophenone, 2-hydroxy-5-chlorobenzophenone, 2,4-dihydroxybenzophenone, 2,2 ' - Dihydroxy-4-methoxybenzophenone, 2,2 ' -dihydroxy-4,4 ' -dimethoxybenzophenone, 2,2 ' ,4,4 ' -tetrahydroxybenzophenone Ketone, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tertiary butylphenyl)benzotriazole, 2-(2-hydroxy-3 ,5-Dimethylphenyl)benzotriazole, 2-(2-methyl-4-hydroxyphenyl)benzotriazole, 2-(2-hydroxy-3-methyl-5-tertiary butyl Phenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tertiary butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dimethylphenyl )-5-methoxybenzotriazole, 2-(2-hydroxy-3-tertiarybutyl-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-5 -Tertiary butylphenyl)-5-chlorobenzotriazole, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-tris

-2-yl)-5-(octyloxy)phenol, 2-(4,6-diphenyl-1,3,5-tri

-2-yl)-5-(hexyloxy)phenol, phenyl salicylate, p-octylphenyl salicylate and the like.

When the encapsulant composition for solar cells of the present invention contains an ultraviolet absorber, the content of the resin is preferably 0.01 to 3.0 parts by mass when the content of the resin is set to 100 parts by mass.

The light stabilizer is not particularly limited as long as it can capture free radicals generated by light degradation, and hindered amine-based compounds, thiol-based compounds, thioether-based compounds, and the like can be used. These can be used alone or in combination of two or more kinds.

-2,4-二基}{(2,2,6,6-四甲基-4-哌啶基)亞胺基}六亞甲{{2,2,6,6-四甲基-4-哌啶基)亞胺基}]、N,N'-雙(3-胺基丙基)伸乙二胺-2,4-雙[N-丁基-N-(1,2,2,6,6-五甲基-4-哌啶基)胺基]-6-氯-1,3,5-三

縮合物、雙(2,2,6,6-四甲基-4-哌啶基)癸二酸酯、2-(3,5-二-三級-4-羥基苄基)-2-正丁基丙二酸雙(1,2,2,6,6-五甲基-4-哌啶基)等。 The above-mentioned light stabilizer is preferably a hindered amine compound. As a specific example thereof, dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6, 6-tetramethylpiperidine polycondensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-tri

-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene{{2,2,6,6-tetramethyl-4 - piperidyl) imino}], N, N '- bis (3-aminopropyl) -2,4-ethylenediamine extending bis [N- butyl -N- (1,2,2, 6,6-Pentamethyl-4-piperidinyl)amino)-6-chloro-1,3,5-tri

Condensate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2-(3,5-di-tertiary-4-hydroxybenzyl)-2-normal Butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl) and the like.

When the encapsulant composition for solar cells of the present invention contains a light stabilizer, the content of the resin is set to 100 mass in terms of the content ratio. In the case of an amount, it is preferably 0.01 to 3.0 parts by mass.

The antioxidant is not particularly limited as long as it can impart thermal stability to sunlight. Monophenolic compounds, bisphenolic compounds, polymer phenolic compounds, sulfur compounds, phosphoric acid compounds can be used. Compound etc. These can be used alone or in combination of two or more kinds.

Examples of the antioxidants include 2,6-di-tertiary butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tertiary butyl-4-ethylphenol, 2, 2 ' -methylene-bis-(4-methyl-6-tertiary butyl phenol), 2,2 ' -methylene-bis-(4-ethyl-6-tertiary butyl phenol), 4,4 ' -thiobis-(3-methyl-6-tertiary butylphenol), 4,4 ' -butylene-bis-(3-methyl-6-tertiary butylphenol), 3 ,9-bis[{1,1-dimethyl-2-{β-(3-tertiarybutyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl}2,4, 8,10-Tetraoxaspiro] 5,5-Undecane, 1,1,3-gin-(2-methyl-4-hydroxy-5-tertiary butylphenyl)butane, 1,3 ,5-Trimethyl-2,4,6-ginseng(3,5-di-tertiarybutyl-4-hydroxybenzyl)benzene, 4-(methylene-3-(3 ' , 5'- Di-tertiary butyl-4 ' -hydroxyphenyl)propionate}methane, bis{(3,3 ' -bis-4 ' -hydroxy-3 ' -tertiary butylphenyl)butyric acid}diol Ester, dilauryl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, triphenyl phosphite, diphenyl isodecyl phosphite, benzene phosphite diisodecyl yl, 4,4 '- butylidene - bis - (3-methyl-6-tert.butyl phenyl - di - tridecyl) phosphite, cyclic neopentanetetrayl bis ( Octadecyl phosphite), ginseng diphenyl phosphite, diisodecyl neopentyl erythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphinphenanthrene-10-oxide, 10-(3,5-di-tertiarybutyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphinphenanthrene-10-oxide, 10-decyloxy-9 ,10-Dihydro-9-oxa-10-phosphinphenanthrene, cyclic neopentane tetrayl bis(2,4-di-tertiary butyl phenyl) phosphite, cyclic neopentane tetrayl bis (2,6-Di-tertiary methylphenyl) phosphite, 2,2-methylene bis(4,6-tertiary butylphenyl) octyl phosphite, etc.

When the encapsulant composition for solar cells of the present invention contains an antioxidant, the content of the resin is preferably 0.05 to 3.0 parts by mass when the content of the resin is set to 100 parts by mass.

The encapsulant composition for solar cells of the present invention can be manufactured by mixing raw material components, but the ion scavenger for solar cells, other components, etc. are preferably in the form of a resin as a matrix and dispersed in the matrix. In particular, when a component that forms a crosslinked structure with the resin, such as a crosslinking agent, is blended, the resin is preferably contained in an uncrosslinked or semi-crosslinked state.

Therefore, when forming the encapsulation layer 13 in Figure 1, it is preferable to use, for example, kneading the encapsulant composition for solar cells of the present invention, and then putting it into an extruder, and then forming a thin wall by T-die molding or calender molding. Shape, and then processed into a predetermined size to obtain an uncrosslinked or semi-crosslinked solar cell module packaging material sheet.

3. Solar cell module

The solar cell module of the present invention, for example, as shown in FIG. 1, includes a solar cell element 11, a front-side transparent protective member 15, a back-side protective member 17, and a transparent protective member 15 on the front side and the back-side protective member Between 17, the encapsulation layer 13 in which the solar cell element 11 is encapsulated (embedded) using the solar cell encapsulant composition of the present invention described above. The solar cell elements 11 are connected to each other by internal connecting wires 19. this In addition, in Figure 1, the current collector electrode and the like are omitted.

The solar cell element 11 has a function of converting light incident on the light-receiving surface into electricity through the photoelectric effect, and preferably includes silicon, compound semiconductors, and the like.

The encapsulating layer 13 is preferably a layer composed of a cross-linked resin composition formed using a solar cell encapsulant composition containing a cross-linking agent, and the solar cell element 11 and the internal connecting wire 19 are fixed in a predetermined position through Embed.

The surface side transparent protective member 15 is usually made of materials with excellent weather resistance, wind pressure resistance, hail resistance, etc. It can be made of polyester resin, polycarbonate resin, or other resin or glass, but it is usually made of sodium It is made of glass such as lime glass.

The back side protective member 17 is usually made of a material having excellent weather resistance such as hydrolysis-resistant polyethylene terephthalate resin and polyvinyl fluoride resin. The back side protection member 17 may also have a function of reflecting light penetrating the encapsulation layer 13.

The manufacturing method of the solar cell module of the present invention is not particularly limited, and conventionally known methods can be applied. For example, an uncrosslinked or semi-crosslinked solar cell module encapsulating material sheet obtained by using a backside protective member and a solar cell encapsulant composition containing a crosslinking agent, a solar cell element, and a solar cell element containing a crosslinking agent can be used. The uncrosslinked or semi-crosslinked solar cell module encapsulating material sheet obtained from the solar cell encapsulant composition of the agent is sequentially laminated with the transparent protective member on the surface side to form a laminate, and then the laminate It is a method of vacuum heating lamination, which is used for heating and pressing in a vacuum state. borrow This vacuum heating lamination enables the solar cell element to be embedded between the two solar cell module encapsulating material sheets, and while forming a cross-linked resin composition, the encapsulation layer and the back side protective member containing this, and , The transparent protective member and the encapsulation layer on the surface side are then integrated separately to manufacture the solar cell module of the present invention.

In the solar cell module of the present invention, since the encapsulation layer 13 contains a special ion trapping agent, in the use of the solar cell, it can not only capture the moisture invaded into the encapsulation layer 13 or the acid generated by hydrolysis, but also Prevents the degradation of the solar cell element 11, and when the transparent protective member on the surface side is made of glass, even if it is regarded as the main cause of PID (Potential-induced degradation; a phenomenon in which high voltage is applied to the solar cell module and the power is greatly reduced) ^{The sodium ions (Na +} ions) from the glass penetrate into the encapsulation layer 13 to prevent the diffusion of the sodium ions (Na + ions), and to suppress the power drop of the solar cell module 10.

[Example]

Hereinafter, the present invention will be specifically explained based on examples. However, the present invention is not limited to the following examples.

1. Evaluation method (1) pH measurement

Measured by the glass electrode type hydrogen ion concentration indicator "D-51" (model name) manufactured by Horiba Manufacturing Co., Ltd. to the aqueous solution after the ion trapping agent is added in the following (2), or the extracted water obtained in the following (3)的pH. Determination It is based on JIS Z 8802 "Method of pH Measurement", and the measurement temperature is 25°C.

^{(2) Na +} ion adsorption capacity of ion trapping agent for solar cell in NaCl aqueous solution

^{The Na +} ion adsorption capacity of the ion trapping agent for solar cells was evaluated by ICP emission spectrometry. The specific evaluation method is as follows.

First, 0.254 g of NaCl was dissolved in 1 L of water to prepare an aqueous solution of 100 ppm of ^{Na + ions.} An ion trapping agent was added to this aqueous solution to have a concentration of 1.0% by mass, and it was mixed thoroughly, and then left to stand. ^{Then, an ion trap was added, and the Na +} ion concentration after 8 hours was measured with an ICP emission spectrometer "iCAP7600 DUO" (model name) manufactured by Thermo Fisher Scientific. ^{After that, the Na +} ion capture rate was calculated according to the following equation.

Na ⁺ ion capture rate = ((initial concentration (100ppm)-Na ⁺ ion concentration after the test (after 8 hours)) / initial concentration (100ppm)) × 100

^{(3) Na +} ion adsorption capacity of the cross-linked resin test piece formed using the encapsulant composition for solar cells

1.0 parts by mass of ion trapping agent for solar cells, 100 parts by mass of ethylene-vinyl acetate copolymer resin "EV150R" (trade name) manufactured by Du Pont-Mitsui Polychemicals, and tertiary butyl peroxide-2-manufactured by ARKEMA Yoshitomi Ethylhexyl carbonate "LUPEROX TBEC" (trade name, crosslinking agent) 0.5 parts by mass, 2,5-dimethyl-2,5-di(tertiarybutyl peroxide) hexane, manufactured by ARKEMA Yoshitomi, "LUPEROX 101" (trade name, crosslinking agent) 0.5 parts by mass, Sartomer's trimethylolpropane trimethacrylate "SR350" (trade name, crosslinking aid) 1.0 parts by mass, Sartomer's heterocyanuric acid After mixing 1.0 parts by mass of triallyl acid "SR533" (trade name, crosslinking aid) with 0.025 parts by mass of sodium chloride manufactured by Kishida Chemical Co., Ltd. to obtain an encapsulant composition for solar cells, it was made by Meiki Seisakusho Co., Ltd. The injection molding machine "M-50A(II)-DM" (model name), the molding temperature was 150°C, and a crosslinked resin test piece (110mm×110mm×2mm) was obtained. In addition, in order to make the ^{difference in the measured values of the Na +} ion concentration between the examples and the comparative examples more significant, the sodium chloride is one having a sodium content of about 100 ppm relative to the ethylene-vinyl acetate copolymer resin.

Next, 10 g of this cross-linked resin test piece was cut to form a small piece (about 5 mm × 5 mm × 2 mm), which was put into a 100 mL plastic container together with 50 mL of pure water, and tightened. Then, the plastic container was allowed to stand at 95°C for 20 hours. Then, analysis and pH measurement of the extracted water containing the components eluted from the cross-linked resin test piece into pure water were performed. ^{The Na +} ion concentration was determined by ICP emission spectrum analysis. In addition, the concentration of acetic acid was measured by ion chromatography.

2. Manufacture and evaluation of ion trapping agent Example 1

After dissolving 0.272 mol of zirconium oxychloride octahydrate in 850 mL of pure water, 0.788 mol of oxalic acid dihydrate was added and dissolved. While stirring this aqueous solution, 0.57 mol of phosphoric acid was added. While stirring, one Reflux was performed at 103°C for 8 hours. After cooling, the obtained precipitate was sufficiently washed with water, and then dried at 150°C to obtain a scaly powder composed of zirconium phosphate. As a result of analyzing this zirconium phosphate, it was confirmed to be α-zirconium phosphate (H type) (hereinafter referred to as "α-zirconium phosphate (Z1)").

The above-mentioned α-zirconium phosphate (Z1) was boiled and dissolved in nitric acid added with hydrofluoric acid, and then subjected to ICP emission spectrometry to obtain the following composition formula.

ZrH _2.03 (PO ₄ ) _2.01 ‧0.05H ₂ O

In addition, the median diameter of α-zirconium phosphate (Z1) measured by the laser diffraction particle size distribution meter "LA-700" (model name) manufactured by Horiba Manufacturing Co., Ltd. was 0.9 μm.

Next, while stirring 1000 mL of a 0.1N-LiOH aqueous solution, 25 g of α-zirconium phosphate (Z1) was added, and this was stirred for 8 hours. After that, the precipitate was washed with water and vacuum dried at 150°C for 20 hours to prepare a lithium ion-substituted α-zirconium phosphate _{composed of ZrLi 1.03} H _1.00 (PO ₄ ) _2.01 ‧0.05H _{2 O.} According to the Karl Fischer method, the moisture content is 0.5%. This lithium ion-substituted α zirconium phosphate is the one with 4 meq/g replaced by lithium ion among the total cation exchange capacity. Hereinafter, it is referred to as "4meq-Li substituted α-zirconium phosphate A1-1".

Next, using the ion scavenger for solar cells composed of the 4meq-Li substituted α-zirconium phosphate A1-1, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 2

Except that the amount of 0.1N-LiOH aqueous solution was 2500mL, the same operation as in Example 1 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7meq/g) replaced by lithium ions by ZrLi _2.03 ( PO ₄ ) _2.01 ‧0.05H ₂ O composed of lithium ion substituted α-zirconium phosphate. The moisture content is 0.3%. Hereinafter referred to as "all Li substituted α-zirconium phosphate A1-2".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all Li-substituted α-zirconium phosphate A1-2, and the results are shown in Table 1.

Example 3

Except that 0.1N-KOH aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 1 was performed to prepare a potassium-substituted α _{composed of ZrK 1.03} H _1.00 (PO ₄ ) _2.01 ‧0.03H _{2 O} -Zirconium phosphate. The moisture content is 0.5%. This potassium-substituted α-zirconium phosphate is the one with 4 meq/g replaced by lithium ions among the total cation exchange capacity. Hereinafter referred to as "4meq-K substituted α-zirconium phosphate A1-3".

Next, using the ion scavenger for solar cells composed of the 4meq-K substituted α-zirconium phosphate A1-3, the various evaluations described above were performed, and the results are shown in Table 1.

Example 4

Except that the amount of 0.1N-KOH aqueous solution was 2500mL, the same operation as in Example 3 was carried out to prepare all the cation exchange groups (cation exchange capacity: 6.7meq/g) replaced by potassium ions by ZrK _2.03 ( PO ₄ ) _2.01 composed of potassium substituted α-zirconium phosphate. The moisture content is 0.4%. Hereinafter referred to as "all-K substituted α-zirconium phosphate A1-4".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-K-substituted α-zirconium phosphate A1-4, and the results are shown in Table 1.

Example 5

After dissolving 0.272 mol of zirconium oxychloride octahydrate with a Hf content of 0.18% in 850 mL of deionized water, 0.788 mol of oxalic acid dihydrate was added and dissolved. While stirring this aqueous solution, 0.57 mol of phosphoric acid was added. While stirring, reflux was performed at 98°C for 8 hours. After cooling, the obtained precipitate was sufficiently washed with water, and then dried at 150°C to obtain a scaly powder composed of zirconium phosphate. As a result of analyzing this zirconium phosphate, it was confirmed to be α-zirconium phosphate (H type) (hereinafter referred to as "α-zirconium phosphate (Z2)").

The above-mentioned α-zirconium phosphate (Z2) was boiled and dissolved in nitric acid added with hydrofluoric acid, and then subjected to ICP emission spectrometry analysis to obtain the following composition formula.

Zr _0.99 Hf _0.01 H _2.03 (PO ₄ ) _2.01 ‧0.05H ₂ O

In addition, the median diameter of α-zirconium phosphate (Z2) is 0.8 μm.

Next, while stirring 1000 mL of a 0.1N-LiOH aqueous solution, 25 g of α-zirconium phosphate (Z2) was added, and this was stirred for 8 hours. After that, the precipitate was washed with water and vacuum dried at 150°C for 20 hours to prepare a lithium ion-substituted α-zirconium phosphate _{composed of Zr 0.99} Hf _0.01 Li _1.03 H _1.00 (PO ₄ ) _2.01 ‧0.2H _{2 O.} According to the Karl Fischer method, the moisture content is 0.4%. This lithium ion-substituted α zirconium phosphate is the one with 4 meq/g replaced by lithium ion among the total cation exchange capacity. Hereinafter, it is referred to as "4meq-Li substituted α-zirconium phosphate A2-1".

Next, using the ion scavenger for solar cells composed of the 4meq-Li substituted α-zirconium phosphate A2-1, the various evaluations described above were performed, and the results are shown in Table 1.

Example 6

Except that the amount of 0.1N-LiOH aqueous solution was 2500mL, the same operation as in Example 5 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7meq/g) replaced by lithium ions by Zr _0.99 Hf _0.01 Li _2.03 (PO ₄ ) _2.01 ‧0.1H ₂ O composed of lithium ion substituted α-zirconium phosphate. The moisture content is 0.3%. Hereinafter, it is referred to as "all Li-substituted α-zirconium phosphate A2-2".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Li-substituted α-zirconium phosphate A2-2, and the results are shown in Table 1.

Example 7

Except that the 0.1N-KOH aqueous solution was used instead of the 0.1N-LiOH aqueous solution, the same operation as in Example 5 was carried out to produce a Zr _0.99 Hf _0.01 K _1.03 H _1.00 (PO ₄ ) _2.01 ‧0.03H ₂ O Potassium-substituted α-zirconium phosphate. The moisture content is 0.5%. This potassium-substituted α-zirconium phosphate is the one with 4 meq/g replaced by lithium ions among the total cation exchange capacity. Hereinafter referred to as "4meq-K substituted α-zirconium phosphate A2-3".

Next, using the ion scavenger for solar cells composed of the 4meq-K substituted α-zirconium phosphate A2-3, the various evaluations described above were performed, and the results are shown in Table 1.

Example 8

Except that the amount of 0.1N-KOH aqueous solution was 2500mL, the same operation as in Example 7 was carried out to prepare all the cation exchange groups (cation exchange capacity: 6.7meq/g) replaced by potassium ions by Zr _0.99 Hf _0.01 K _2.03 (PO ₄ ) _2.01 composed of potassium substituted α-zirconium phosphate. The moisture content is 0.4%. Hereinafter referred to as "all-K substituted α-zirconium phosphate A2-4".

Next, using the ion scavenger for solar cells composed of the all-K-substituted α-zirconium phosphate A2-4, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 9

Except that 2500 mL of 0.1N-Rb ₂ CO ₃ aqueous solution was used instead of the 0.1N-LiOH aqueous solution, the same operation as in Example 5 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7 meq/g) by rubidium Ion-substituted rubidium-substituted α-zirconium phosphate. The moisture content is 0.5%. Hereinafter referred to as "all Rb substituted α-zirconium phosphate A2-5".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all Rb-substituted α-zirconium phosphate A2-5, and the results are shown in Table 1.

Example 10

Except that 2500 mL of 0.1N-Cs ₂ CO ₃ aqueous solution was used instead of the 0.1N-LiOH aqueous solution, the same operation as in Example 5 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7 meq/g) through cesium Ion-substituted cesium-substituted α-zirconium phosphate. The moisture content is 0.4%. Hereinafter referred to as "all Cs substituted α-zirconium phosphate A2-6".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Cs-substituted α-zirconium phosphate A2-6, and the results are shown in Table 1.

Example 11

Except that 2500 mL of 0.1N-(CH ₃ COO) ₂ Mg aqueous solution was used instead of the 0.1N-LiOH aqueous solution, the same operation as in Example 5 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7 meq/g ) Magnesium-substituted α-zirconium phosphate substituted by magnesium ions. The moisture content is 0.5%. Hereinafter referred to as "all Mg substituted α-zirconium phosphate A2-7".

Secondly, using this all-Mg substituted α-zirconium phosphate A2-7 The above-mentioned various evaluations were performed on the ion scavenger for solar cells, and the results are shown in Table 1.

Example 12

Except that 2500 mL of 0.1N-(CH ₃ COO) ₂ Ca aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 5 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7 meq/g ) Calcium-substituted α-zirconium phosphate substituted by calcium ions. The moisture content is 0.6%. Hereinafter referred to as "all-Ca substituted α-zirconium phosphate A2-8".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Ca substituted α-zirconium phosphate A2-8, and the results are shown in Table 1.

Example 13

405 g of 75% phosphoric acid was added to 400 mL of deionized water, and while stirring this aqueous solution, _{137 g of titanyl sulfate (TiO 2} conversion content: 33%) was added. While stirring, reflux was performed at 100°C for 48 hours. After cooling, the obtained precipitate was thoroughly washed with water and dried at 150°C to obtain a scaly powder composed of titanium phosphate. As a result of analyzing this titanium phosphate, it was confirmed to be α-titanium phosphate (H type).

The above-mentioned α-titanium phosphate was boiled and dissolved in nitric acid added with hydrofluoric acid, and then subjected to ICP emission spectrometry to obtain the following composition formula.

TiH _2.03 (PO ₄ ) _2.01 ‧0.1H ₂ O

In addition, the median diameter of α-titanium phosphate was measured and found to be 0.7 μm.

Next, 25 g of α-titanium phosphate was added to 1000 mL of 0.1N-LiOH aqueous solution while stirring, and this was stirred for 8 hours. Thereafter, the precipitate was washed with water and vacuum dried at 150°C for 20 hours to prepare a lithium ion substituted α-titanium phosphate _{composed of TiLi 1.03} H _1.00 (PO ₄ ) _2.01 ‧0.2H _{2 O.} The moisture content is 0.5%. This lithium-ion-substituted alpha titanium phosphate is the one with 4 meq/g replaced by lithium ions among the total cation exchange capacity. Hereinafter, it is referred to as "4meq-Li substituted α-titanium phosphate B-1".

Next, using the ion scavenger for solar cells composed of the 4meq-Li substituted α-titanium phosphate B-1, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 14

Except that the amount of 0.1N-LiOH aqueous solution was 2500mL, the same operation as in Example 13 was performed to prepare all cation exchange groups (cation exchange capacity: 7.0meq/g) replaced by lithium ions with TiLi _2.03 ( PO ₄ ) _2.01 ‧0.1H ₂ O composed of lithium ion substituted α-titanium phosphate. The moisture content is 0.4%. Hereinafter, it is referred to as "all Li-substituted α-titanium phosphate B-2".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all Li-substituted α-titanium phosphate B-2, and the results are shown in Table 1.

Example 15

Except that 0.1N-KOH aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 13 was performed to prepare a potassium ion substituted type _{composed of TiK 1.03} H _1.00 (PO ₄ ) _2.01 ‧0.05H _{2 O} α-Titanium phosphate. The moisture content is 0.4%. Hereinafter, it is referred to as "4meq-K substituted α-titanium phosphate B-3".

Next, using the ion scavenger for solar cells composed of the 4meq-K substituted α-titanium phosphate B-3, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 16

Except that the amount of 0.1N-KOH aqueous solution was 2500 mL, the same operation as in Example 13 was performed to prepare all cation exchange groups (cation exchange capacity: 7.0 meq/g) replaced by potassium ions with TiK _2.03 ( PO ₄ ) _2.00 composed of potassium substituted α-titanium phosphate. The moisture content is 0.5%. Hereinafter, it is referred to as "all-K substituted α-titanium phosphate B-4".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-K-substituted α-titanium phosphate B-4, and the results are shown in Table 1.

Example 17

Except that 2500 mL of 0.1N-Rb ₂ CO ₃ aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 13 was performed to prepare all cation exchange groups (cation exchange capacity: 7.0 meq/g) by rubidium Ion-substituted rubidium-substituted α-titanium phosphate. The moisture content is 0.4%. Hereinafter referred to as "all Rb substituted α-titanium phosphate B-5".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Rb-substituted α-titanium phosphate B-5, and the results are shown in Table 1.

Example 18

Except that 2500 mL of 0.1N-Cs ₂ CO ₃ aqueous solution was used instead of the 0.1N-LiOH aqueous solution, the same operation as in Example 13 was performed to prepare all cation exchange groups (cation exchange capacity: 7.0 meq/g) through cesium Ion-substituted cesium-substituted α-titanium phosphate. The moisture content is 0.5%. Hereinafter referred to as "all Cs substituted α-titanium phosphate B-6".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Cs-substituted α-titanium phosphate B-6, and the results are shown in Table 1.

Example 19

Except that 2500 mL of 0.1N-(CH ₃ COO) ₂ Mg aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 13 was performed to prepare all cation exchange groups (cation exchange capacity: 7.0 meq/g ) Magnesium-substituted α-titanium phosphate substituted by magnesium ions. The moisture content is 0.5%. Hereinafter referred to as "all Mg substituted α-titanium phosphate B-7".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Mg-substituted α-titanium phosphate B-7, and the results are shown in Table 1.

Example 20

Except that 2500 mL of 0.1N-(CH ₃ COO) ₂ Ca aqueous solution was used instead of the 0.1N-LiOH aqueous solution, the same operation as in Example 13 was performed to prepare all cation exchange groups (cation exchange capacity: 7.0 meq/g ) Calcium-substituted α-titanium phosphate substituted by calcium ions. The moisture content is 0.4%. Hereinafter, it is referred to as "all-Ca substituted α-titanium phosphate B-8".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Ca substituted α-titanium phosphate B-8, and the results are shown in Table 1.

Example 21

The all-Li-substituted α-zirconium phosphate A1-2 and the all-K-substituted α-zirconium phosphate A1-4 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 22

The all-Li-substituted α-zirconium phosphate A1-2 and the all-Li-substituted α-zirconium phosphate A2-2 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 23

The all-Li-substituted α-zirconium phosphate A1-2 and the all-K-substituted α-zirconium phosphate A2-4 are mixed at a mass ratio of 1:1 to obtain ion capture for solar cells Agent. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 24

The all-Li-substituted α-zirconium phosphate A1-2 and the all-Li-substituted α-titanium phosphate B-2 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 1.

Example 25

The all-Li-substituted α-zirconium phosphate A1-2 and the all-K-substituted α-titanium phosphate B-4 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 26

The all-K-substituted α-zirconium phosphate A1-4 and the all-Li-substituted α-zirconium phosphate A2-2 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 27

The all-K-substituted α-zirconium phosphate A1-4 and the all-K-substituted α-zirconium phosphate A2-4 are mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 28

The all K-substituted α-zirconium phosphate A1-4 and all Li-substituted α-phosphate Titanium B-2 was mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 29

The all-K-substituted α-zirconium phosphate A1-4 and the all-K-substituted α-titanium phosphate B-4 are mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 30

The all-Li-substituted α-zirconium phosphate A2-2 and the all-K-substituted α-zirconium phosphate A2-4 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 31

The all-Li-substituted α-zirconium phosphate A2-2 and the all-Li-substituted α-titanium phosphate B-2 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 32

The all-Li-substituted α-zirconium phosphate A2-2 and the all-K-substituted α-titanium phosphate B-4 were mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 33

All-K-substituted α-zirconium phosphate A2-4 and all-Li-substituted α-titanium phosphate B-2 are mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 34

All-K-substituted α-zirconium phosphate A2-4 and all-K-substituted α-titanium phosphate B-4 are mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Example 35

All Li-substituted α-titanium phosphate B-2 and all K-substituted α-titanium phosphate B-4 are mixed at a mass ratio of 1:1 to obtain an ion scavenger for solar cells. Then, the above-mentioned various evaluations were performed, and the results are shown in Table 2.

Comparative example 1

The inorganic ion exchanger "IXE100" (trade name) manufactured by Toagosei Co., Ltd., which is a non-cationically substituted α-zirconium phosphate (Type H), was used for various evaluations. The results are shown in Table 2.

Comparative example 2

Except that 2500 mL of 0.1N-NaOH aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 5 was performed to prepare all cation exchange groups (cation exchange capacity: 6.7 meq/g) replaced by sodium ions Sodium-substituted α-zirconium phosphate composed of Zr _0.99 Hf _0.01 Na _2.03 (PO ₄ ) _2.01 ‧0.05H _{2 O.} The moisture content is 0.5%. Hereinafter, it is referred to as "all Na-substituted α-zirconium phosphate".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Na-substituted α-zirconium phosphate, and the results are shown in Table 2.

Comparative example 3

The α-titanium phosphate (H type) prepared in Example 13 was directly used for various evaluations. The results are shown in Table 2.

Comparative example 4

Except that 2500 mL of 0.1N-NaOH aqueous solution was used instead of 0.1N-LiOH aqueous solution, the same operation as in Example 13 was performed to prepare all the cation exchange groups (cation exchange capacity: 7.0 meq/g) replaced by sodium ions. Sodium-substituted α-titanium phosphate composed of TiNa _2.03 (PO ₄ ) _2.00 ‧0.05H _{2 O.} The moisture content is 0.5%. Hereinafter, it is referred to as "all Na-substituted α-titanium phosphate".

Next, the above-mentioned various evaluations were performed using the ion scavenger for solar cells composed of the all-Na-substituted α-titanium phosphate, and the results are shown in Table 2.

Comparative example 5

After drying the Y-type zeolite "MIZUKASIEVES Y-520" (trade name) manufactured by Mizusawa Chemical Co., Ltd. at 150°C for 20 hours, various evaluations were performed. set. The results are shown in Table 2.

It can be seen from Table 1 and Table 2 that the ion trapping agents for solar cells of Examples 1 to 35 ^{have a high capturing rate of Na +} ions in the NaCl aqueous solution, and the pH variation is within 1. In addition, even in the extracted water after immersing the crosslinked resin test piece in pure water, the ion scavengers for solar cells of Examples 1 to 35 also showed high performance in inhibiting the elution of ^{Na + ions.} Based on these results, the ion scavenger of the present invention not only adsorbs Na ⁺ ions, which are considered to be the cause of the PID of solar cells, but also has no change in pH. Therefore, it can be suppressed without promoting the degradation of the encapsulating resin. The PID of the solar cell.

[Industrial availability]

The ion trapping agent for solar cells of the present invention can adsorb Na ⁺ ions that are the cause of the PID of solar cells with high selectivity and is not easy to release H ⁺ ions, so it can be included in the formation of solar cell modules. Encapsulation layer, backside protection member and other ground members. Thereby, a solar cell with excellent durability can be formed. Moreover, it can also be added to the paste of a silver electrode, etc. and used.

10‧‧‧Solar battery module

11‧‧‧Solar cell components

13‧‧‧Encapsulation layer

15‧‧‧Transparent protective member on the surface side

17‧‧‧Back side protection member

19‧‧‧Internal connection line

Claims (6)

An ion trapping agent for solar cells, characterized in that 0.1~6.7 meq/g of the total ion exchange capacity containing (A) ion exchange groups is selected from lithium ions, potassium ions, cesium ions, rubidium ions, magnesium ions, and calcium ions. Among the total ion exchange capacity of at least one ion of (a1) substituted α-zirconium phosphate and (B) ion exchange group, 0.1 to 7.0 meq/g is selected from lithium ion, potassium ion, cesium ion, rubidium At least one of α-titanium phosphate substituted with at least one ion (b1) of ions, magnesium ions, and calcium ions. The ion trapping agent for solar cells according to claim 1, wherein the α-zirconium phosphate before being substituted by the ion (a1) is a compound represented by the following formula (1): Zr _1-x Hf _x H _a (PO ₄ ) _b ‧mH ₂ O (1) (where 0≦x≦0.2, 2<b≦2.1, a is a number that satisfies 3b-a=4, and 0≦m≦2). The ion trapping agent for solar cells according to claim 1, wherein the α-titanium phosphate before being substituted by the ion (b1) is a compound represented by the following formula (2): TiH _s (PO ₄ ) _t ‧nH ₂ O ( 2) (In the formula, 2<t≦2.1, s is a number satisfying 3t-s=4, and 0≦n≦2). An encapsulant composition for solar cells, which is characterized by containing as Claim 1 Ion trapping agent for solar cells, and resin. The encapsulant composition for solar cells according to claim 4, wherein the above-mentioned resin includes ethylene·vinyl acetate copolymer resin. A solar cell module, characterized by comprising solar cell elements, a front-side transparent protection member, a back-side protection member, and between the front-side transparent protection member and the back-side protection member, the solar cell as claimed in claim 4 is used An encapsulant layer obtained by encapsulating the above-mentioned solar cell element with an encapsulant composition.

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