Sealing material sheet for solar-cell module and solar-cell module using the same

Patent metadata

Field	Value
Publication number	US-12015094-B2
Application number	US-202217958948-A
Country	US
Kind code	B2
Filing date	Oct 3, 2022
Priority date	Apr 11, 2019
Publication date	Jun 18, 2024
Grant date	Jun 18, 2024

Abstract

To provide a sealing material sheet for a solar-cell module that has high productivity without performing crosslinking processing, and has a high tensile shear adhesion force at normal temperature at a high level in addition to heat resistance and molding characteristics. A sealing material sheet is a multi-layer sheet using a polyethylene-based resin as a base resin, a core layer has a density of 0.880 g/cm 3 to 0.895 g/cm 3 and a melting point of 70° C. or higher, a skin layer has a density of 0.880 g/cm 3 to 0.910 g/cm 3 and a melting point of 90° C. or lower and contains a silane-modified polyethylene-based resin, a weight average molecular weight of the silane-modified polyethylene-based resin contained in the skin layer 11 in terms of polystyrene is 70000 to 120000, and a polymerized silane amount of the skin layer in the whole resin component is 300 ppm to 2000 ppm.

First claim

What is claimed is:

1. A sealing material sheet for a solar-cell module,
the sealing material sheet being a multi-layer sheet comprising:
a core layer composed of a polyethylene-based resin as a base resin, and
skin layers, which are laminated directly on both sides of the core layer and disposed on both outermost surfaces of the core layer and are composed of a polyethylene-based resin as a base resin,

wherein:
the multi-layer sheet has a total thickness of 250 μm or more and 600 μm or less,
the core layer has a thickness of 200 μm or more and 400 μm or less and has a density that is in a range of from 0.880 g/cm 3 to 0.930 g/cm 3 and a melting point of 70° C. or higher;
the skin layers have a thickness of 30 μm or more and 100 μm or less and have a density that is in a range of from 0.880 g/cm 3 to 0.910 g/cm 3 and a melting point of 90° C. or lower;
the core layer and the skin layers contain a silane-modified polyethylene-based resin, a weight average molecular weight of the silane-modified polyethylene-based resin present in the core layer and the skin layers in terms of polystyrene is 70000 or more;
a polymerized silane amount of the core layer with respect to a total amount of all resin components is in a range of from 30 ppm to 2000 ppm;
a polymerized silane amount of the skin layers with respect to a total amount of all resin components is in a range of from 300 ppm to 2000 ppm;
a melt mass flow rate of the sealing material sheet is 3.0 g/10 min or more and less than 3.8 g/10 min in terms of average of the whole layer;
a tensile shear adhesion strength measured by a tensile shear adhesion strength measurement experiment is at least 1000 N; and
the tensile shear adhesion strength measurement experiment measures the tensile shear adhesion strength by a test method according to JIS K7197 at a tensile rate of 1.27 mm/min, after preparing an evaluation sample using two colorless strengthened glass plates having a flat surface, placing a sealing material sheet cut to 2.5 cm×1.27 cm between the two glass plates, and performing a vacuum heating lamination treatment at a set temperature of 150° C. under a vacuum aspiration for 3 minutes and an atmospheric pressurization of 7 minutes.

2. The sealing material sheet according to claim 1 , wherein the weight average molecular weight of the silane-modified polyethylene-based resin present in the skin layers in terms of polystyrene is in a range of from 90000 to 120000.

3. The sealing material sheet according to claim 1 , wherein the melting points of the core layer and the skin layers are both in a range of from 70° C. to 80° C.

4. A solar-cell module obtained by sequentially laminating
a transparent front substrate,
a sealing material of a light receiving surface side,
a solar cell element,
a sealing material of a non-light receiving surface side, and
a rear-surface protecting substrate,
the sealing material of the light receiving surface side and the sealing material of the non-light receiving surface side being the sealing material sheet according to claim 1 .

5. The solar-cell module according to claim 4 , wherein both the transparent front substrate and the rear-surface protecting substrate are a protecting substrate made of glass.

6. The solar-cell module according to claim 5 , wherein the solar-cell module is a frameless module having no protecting frame that surrounds a circumference of a side surface of a module laminate interposed between the protecting substrates made of glass to maintain a shape of the module laminate.

7. The solar-cell module according to claim 4 , wherein,
in a surface of the solar cell element, convex portions formed by a part of the surface protruding in a line-shaped manner or a dot-shaped manner exist, the convex portions being buried inside the sealing material sheet laminated on the surface, and
a thickness of the convex portion is in a range of from 50% to 90% of a thickness of the sealing material sheet laminated on the surface of the solar cell element.

8. The sealing material sheet according to claim 1 , wherein the sealing material sheet does not undergo crosslinking treatment.

9. The sealing material sheet according to claim 1 , wherein the melting point of the skin layers is 80° C. or lower.

10. The sealing material sheet according to claim 1 , wherein the melting point of the core layer is in a range of from 80° C. to 90° C.

11. The sealing material sheet according to claim 1 , wherein a melt mass flow rate of the core layer is higher than a melt mass flow rate of the skin layers.

12. The sealing material sheet according to claim 1 , wherein the density of the core layer is in a range of from 0.885 g/cm 3 to 0.895 g/cm 3 .

13. The sealing material sheet according to claim 1 , wherein the density of the skin layers is in a range of from 0.880 g/cm 3 to 0.899 g/cm 3 .

14. The sealing material sheet according to claim 1 , wherein the core layer and the skin layers both do not contain a crosslinking agent.

Assignees

• Dainippon Printing Co Ltd

Inventors

• Saeki Kosuke
• Yoneda Shinya
• Tanaka Jun
• Tamaki Hiroaki
• Nagino Shinsuke
• Obonai Naohiro

Classifications

• H10F19/807

  Double-glass encapsulation, e.g. photovoltaic cells arranged between front and rear glass sheets · CPC title

• H10F19/85

  Protective back sheets · CPC title

• H10F19/804 Primary

  Materials of encapsulations · CPC title

• B32B27/08

  of synthetic resin · CPC title

• B32B2457/12

  Photovoltaic modules · CPC title