This porous diaphragms plastics and novel diaphragms thus obtained

摘要

A method is disclosed for manufacturing novel electrolytic cell diaphragms which are consolidated by a fluorinated polymer resin. The method comprises agitating a suspension of asbestos fibers in water, a sulfonic anionic surfactant, a fluorinated polymer resin latex and a solid mineral pore-former, to form a stable, homogeneous suspension, depositing and filtering the suspension on a grid or screen to produce a preform. The preform is dried, sintered at a temperature above the crystalline melting point of the fluorinated polymer resin, and the solid mineral pore-former is removed to form a uniform, porous membrane having uniform pore size. This membrane is combined with a reinforcing element by integrating the reinforcing element with the anode face of the membrane. The reinforcing element has a structure which is at least as open with respect to the passage of liquor as the porous membrane. The novel diaphrams are particularly useful in the electrolysis of alkali metal chlorides.