PURPOSE: To obtain a polyvinylidene fluoride excellent in mechanical strength, thermochemical resistance or the like in good productivity by polymerizing vinylidene fluoride in an aq. emulsion in the presence of an org. peroxide and a chain transfer agent at a specific temp.
CONSTITUTION: Vinylidene fluoride is polymerized in an aq. emulsion in the presence of an org. peroxide (e.g.; di-tert-butylperoxide) and a chain transfer agent (e.g.; chloroform) within a temp. range of 95-120°C. By this method, a polyvinylidine fluoride characterized by that tail to tail and head to head transfer amts. are 5-5.5 mol.%, a yield point is 50 MPa or more, elastic modulus is 1,500 MPa (measured at 23°C according to an ASTM D-1708 method) or more and a melt flow index (measured at 230°C under load of 5 kg according to an ASTM D-1238 method) is 1-25 g/10 min is obtained. The obtained polyvinylidene fluoride is suitable as a material for producing a pipe, a valve or a tank.
BINCHIENTSUO ARUCHIETSURA
MAAGERIITA ARUBAANO