Solar cell sealing material

Abstract

Provided is a solar cell sealing material excellent in balance between transparency and water vapor barrier property.　This solar cell sealing material contains an ethylene-α-olefin copolymer (A) that is a copolymer of ethylene and a C4-10 α-olefin and that satisfies the following requirements (1) and (2). (1) The density is within a range of 885 kg / m3 or more and 915 kg / m3 or less. (2) The melt flow rate (MFR) under a 2.16 kg load at 190°C is within a range of 0.1 g / 10 min or more and 100 g / 10 min or less.

Claims

1. A solar cell encapsulant comprising an ethylene-α-olefin copolymer (A) which is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, and which satisfies the following requirements (1) and (2): (1) Density of 885 kg / m³ ３ More than 915kg / m ３ The following ranges apply: (2) The melt flow rate (MFR) at a load of 2.16 kg at 190°C is in the range of 0.1 g / 10 min to 100 g / 10 min.

2. The solar cell encapsulant according to claim 1, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirements (3) and (4): (3) In cross-fractionation chromatography (CFC) measurement, the proportion (X) of components that elute at 75°C or higher is 0.5% by mass or more and 30% by mass or less. (4) In cross-fractionation chromatography (CFC) measurement, the weight-average molecular weight (Mw) of components that elute at 75°C or higher is Ｘ ) and the weight-average molecular weight (Mw) of the entire sample. Ｔ ) Ratio (Mw Ｘ / Mw Ｔ ) is less than 1.

3. The solar cell encapsulant according to claim 2, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirement (5). (5) In the elution curve obtained from cross-fractional chromatography (CFC) measurement, the full width at half maximum (temperature range at half peak height) of the highest elution peak is 5°C or more and 35°C or less.

4. The solar cell encapsulant according to claim 3, further comprising another thermoplastic resin other than ethylene-α-olefin copolymer (A).

5. The solar cell encapsulant according to claim 4, wherein the other thermoplastic resin is a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms, and is an ethylene-α-olefin copolymer (B) that satisfies the following requirements (1') and (2'): (1') Density of 860 kg / m³ ３ More than 885kg / m ３ It is in the range of less than. (2') The melt flow rate (MFR) at a load of 2.16 kg at 190°C is 0.1 g / 10 min or more and 100 g / 10 min or less.

6. A solar cell module comprising the solar cell encapsulant described in any one of claims 1 to 5.

7. The solar cell encapsulant according to any one of claims 1 to 5, wherein the solar cell is a thin-film solar cell.

8. The solar cell encapsulant according to claim 7, wherein the thin-film solar cell is a perovskite solar cell.

Images