Patent ID: 7968649

Claim:
A method of forming a thin film comprising a mixture of a vinylidene fluoride homopolymer containing not less than 70% by mass of I-form crystal structure having a number average degree of polymerization of 3 to 20 and other polymer, wherein the other polymer is soluble in a solvent comprising an organic solvent having a dipole moment of not less than 2.8 alone, or in a solvent comprising the organic solvent as a part thereof; said method comprises preparing a solution of a mixture of a vinylidene fluoride homopolymer having a number average degree of polymerization of 3 to 20 and the other polymer in a solvent comprising an organic solvent having a dipole moment of not less than 2.8 alone or comprising the organic solvent as a part thereof, applying the solution of the mixture of the vinylidene fluoride homopolymer and the other polymer to a substrate, and evaporating said solvent.