| abstract |
1364683 Diffusion membrane YUASA BATTERY CO Ltd 29 July 1971 [13 Aug 1970 25 Jan 1971] 35657/71 Heading B1X [Also in Divisions B5 and C3] To produce microporous diaphragms for use as diffusion membranes or ion exchange membranes, an aqueous dispersion of PTFE containing an inorganic filler and a powdered soluble salt is stirred and kneaded to produce a plastic solid which may then be shaped into a sheet, heating followed by washing of the sheet in water to remove the soluble salt which is preferably sodium chloride gives the porous article. A reinforcing net of tetrafluoroethylenehexafluoropropylene, PTFE, polyethylene, polyvinyl chloride, polyvinylidene may be rolled into the sheet before washing. The inorganic filler is preferably barium sulphate. Specification 1,081,046 is referred to. |