| 摘要 |
1,213,472. Fuel cell membranes. SIEMENS A.G. 13 Nov., 1967 [3 Dec., 1966; 8 Sept., 1967], No. 51623/67. Heading H1B. [Also in Divisions C3, D1 and D2] A membrane for use in an electrochemical cell, particularly a fuel cell, comprises a fibrous material and a polymeric binder formed by hydrolysing in situ a copolymer of butadiene, styrene and acrylonitrile. The hydrolytic agent may be an alkali, in particular the alkaline electrolyte in the cell. The fibrous material may be of asbestos, glass, carbon or polypropylene fibres in the form of a felt, fleece, woven fabric or paper. The copolymer may be cross-linked e;g. by adding a peroxide to the binder before it is applied to the fibrous material, and subsequently heating the finished diaphragm to cross-link it. In Example 1, the copolymer is added to an aqueous dispersion of asbestos fibres and precipitated by ammonium alum. In Example 2, a felt of carbon fibres is impregnated with a dispersion of the polymer, introduced into a bath of ammonium alum solution, washed, pressed and dried. In both examples, the hydrolysis is with KOH. |
