Patent ID: 7208555

Claim:
A process for preparing a polyvinylidene fluoride copolymer, wherein the ratio of the scattered-light intensity (I) for a 15% solution of the polyvinylidene fluoride copolymer in dimethylformamide solvent to the scattered-light intensity (I 0 ) for dimethylformamide, (I/I 0 ), is 10 or lower, wherein slurry or wet cake of a polyvinylidene fluoride copolymer obtained by suspension polymerization is dispersed in water or an organic solvent in which the copolymer is insoluble; the resulting mixture is stirred; after stirring, the mixture is settled; after settling, the copolymer particles floating in the upper part of the mixture are separated from the copolymer particles precipitated in the lower part of the mixture; the operations of stirring, settling and separation are repeated; and then, the copolymer particles floating in the upper part of the mixture is recovered.