PRODUCTION OF POROUS MEMBRANE OF HYDROPHILIC POLYVINYLIDENE FLUORIDE RESIN

摘要

PURPOSE:To produce a porous membrane having excellent water permeability and resistance to chemicals and heat and suitable for use in the filtration of water-based liquids, by treating a porous membrane of polyvinylidene fluoride resin with an aq. soln. of an alkali. CONSTITUTION:A porous membrane (e.g. one having an average particle size of 0.01-5mu, a porosity of 30-95% and a section thickness of 0.005-25mm.) of polyvinylidene fluoride resin or said resin and a hydrophilic inorg. fine powder such as fine silicic acid powder, is treated with an aq. soln. of an alkali. If desired, the hydrophilic inorg. fine powder is removed to produce the titled porous membrane. This membrane undergoes no change in water permeability with time, has excellent resistance to heat and chemicals and is suitable for use in the filtration of water and water-based liquids.