Fluorine-containing resin film and solar cell module

Abstract

Disclosed is a fluorine-containing resin film which is formed from a fluorine-containing resin composition and has a thickness of 10 to 50 μm, wherein the fluorine-containing resin composition is prepared by adding 10 to 30 parts by mass of titanium oxide or a composite-oxide-type inorganic pigment to 100 parts by mass of a resin component comprising 60 to 95 parts by mass of a vinylidene fluoride resin and 5 to 40 parts by mass of a methacrylic acid ester resin, and wherein the peak intensity ratio of a II-type crystal, which is expressed by (A) / ((A)+(B))×100 wherein A represents the peak height at 840 cm−1 and B represents the peak height at 765 cm−1 in a measurement chart produced by an infrared absorption spectrum, is 60% or more and the total crystallinity is 30% or more as calculated from an X-ray diffraction profile.

Description

TECHNICAL FIELD[0001]The present invention relates to a fluorine-containing resin film, a manufacturing method thereof, a backing sheet for a solar cell module formed using said fluorine-containing resin film, and a solar cell module comprising said backing sheet.BACKGROUND ART[0002]Vinylidene fluoride-based resins have been widely used in fields requiring long-term durability in order to take advantage of their exceptional weather resistance, heat resistance, contamination resistance, chemical resistance, solvent resistance, mechanical properties and secondary workability. In particular, films consisting of vinylidene fluoride resins are often used as solar cell backing sheets to take advantage of their cost when formed into thin films.[0003]However, the demands on long-term reliability for solar cell backing sheet applications have become stricter, requiring use under severe conditions or longer life. In order to achieve such longer life, a method of adding a UV absorbing agent to...

AI Technical Summary

Benefits of technology

[0005]The present invention was made in view of the above circumstances, and has the purpose of offering a fluorine-containing resin film that is suitable for use as a film for solar cell backing sheets, excelling in weather resistance and size stability, with particularly little discoloration in hot and humid environments.

[0007]As a result of diligent research into solving the above-described problems, the present inventors discovered that the problems can be solved by controlling the crystal components of a vinylidene fluoride-based resin in a resin composition by adjusting the amount of components of specific crystal systems, in addition to controlling the degree of crystallinity to within a standard range, thereby resulting in the present invention.

[0012]The fluorine-containing resin film of the present invention is a film that excels in weather resistance and size stability, and has especially little discoloration in hot and humid environments, suitable for use as a backing sheet for solar cell modules, and enabling a solar cell module using it to be obtained.

Problems solved by technology

However, the demands on long-term reliability for solar cell backing sheet applications have become stricter, requiring use under severe conditions or longer life.

However, even with such a film, the film can be discolored when exposed to a hot and humid environment for a long period of time.

This discoloration signifies the creation of double bonds due to a defluorination reaction in the vinylidene fluoride-based resin, which degrades the appearance and reduces the long-term resistance and long-term reliability.

However, they cannot be considered to be necessarily suitable for use in solar cell backing sheets due to problems in cost, secondary workability and the like.