PRODUCTION METHOD OF &bgr; TYPE POLYVINYLIDENE FLUORIDE FILM, &bgr; TYPE POLYVINYLIDENE FLUORIDE FILM, AND PIEZOELECTRIC TYPE SENSOR HAVING &bgr; TYPE POLYVINYLIDENE FLUORIDE FILM

摘要

PROBLEM TO BE SOLVED: To provide a production method of a &bgr; type polyvinylidene fluoride film that can be produced without requiring a large scale facility and by a simple method, in which a piezoelectric characteristic is excellent and purity is high; the &bgr; type polyvinylidene fluoride film; and a piezoelectric type sensor having the &bgr; type polyvinylidene fluoride film.SOLUTION: A production method of a &bgr; type polyvinylidene fluoride film includes: a process in which polyvinylidene fluoride, a water-soluble polar solvent that dissolves the polyvinylidene fluoride and fixes to a &bgr; type, and an organic solvent in which a boiling point is lower than that of the water-soluble polar solvent are mixed to form a coating liquid; a process in which the obtained coating liquid is applied to a basal plate to form an application film; a process in which the application film is dehydrated; and a process in which the dehydrated film is water-washed.