Patent ID: 8460536
Filing Date: 2013-06-11
Classification: C02F,C25B

Abstract:
1. A liquid-permeable diaphragm for use in a chlor-alkali electrolytic cell comprising: (a) a liquid-permeable base mat, said base mat comprising synthetic polymeric material that is at least partially resistant to the environment within said electrolytic cell, and (b) a coating of water-insoluble particulate material on said base mat, the water-insoluble particulate material having been deposited on said base mat from an aqueous slurry of water and particulate material consisting essentially of: (i) at least one oxide, boride, carbide, nitride or silicate of a valve metal, (ii) clay mineral, (iii) hydrous metal oxide chosen from the hydrous oxides of magnesium, the hydrous oxides of zirconium, and mixtures of said hydrous metal oxides, and (iv) from 0.01 to 2 weight percent of alkali metal polyphosphate.