Abstract: Provided are vinylidene fluoride copolymers exhibiting higher adhesion with respect to metal foils than do conventional vinylidene fluoride copolymers, and to provide uses of the vinylidene fluoride copolymers. The vinylidene fluoride copolymers are obtained by copolymerizing vinylidene fluoride with a compound represented by Formula (A). In Formula (A), R1, R2 and R3 are each independently a hydrogen atom, a chlorine atom or an alkyl group; and X is an atomic group with a molecular weight of not more than 500 containing a heteroatom and having a main chain composed of 1 to 20 atoms, or is a heteroatom.

Abstract: Provided is a vinylidene fluoride polymer powder exhibiting excellent solubility in aprotic polar solvents, and a vinylidene fluoride polymer solution obtained from the powder and an aprotic polar solvent. The vinylidene fluoride polymer powder has an NMP penetration rate of 12 to 100% as measured by an NMP penetration test.

Abstract: The present invention relates to a process for producing a vinylidene fluoride polymer solution, which involves dissolving heat-treated vinylidene fluoride polymer powder into an aprotic polar solvent. The heat-treated vinylidene fluoride polymer powder is obtained by heat treating raw vinylidene fluoride polymer powder at such a temperature that the temperature of the vinylidene fluoride polymer powder is not less than 125° C. to less than a crystal melting temperature (Tm) of the polymer.

Abstract: Provided are vinylidene fluoride copolymers exhibiting higher adhesion with respect to metal foils than do conventional vinylidene fluoride copolymers, and to provide uses of the vinylidene fluoride copolymers. The vinylidene fluoride copolymers are obtained by copolymerizing vinylidene fluoride with a compound represented by Formula (A). In Formula (A), R1, R2 and R3 are each independently a hydrogen atom, a chlorine atom or an alkyl group; and X is an atomic group with a molecular weight of not more than 500 containing a heteroatom and having a main chain composed of 1 to 20 atoms, or is a heteroatom.

Abstract: Provided is a process for producing vinylidene fluoride polymer powder that exhibits excellent solubility with respect to aprotic polar solvents, and a process for producing a vinylidene fluoride polymer solution using vinylidene fluoride polymer powder obtained by the polymer powder production process. The process for producing heat-treated vinylidene fluoride polymer powder includes heat treating raw vinylidene fluoride polymer powder at such a temperature that the temperature of the polymer powder is not less than 125° C. to less than the crystal melting temperature (Tm) of the polymer.

Abstract: Provided is a vinylidene fluoride polymer powder exhibiting excellent solubility in aprotic polar solvents, and a vinylidene fluoride polymer solution obtained from the powder and an aprotic polar solvent. The vinylidene fluoride polymer powder has an NMP penetration rate of 12 to 100% as measured by an NMP penetration test.