| 摘要 |
Diaphragm comprising membranes of thickness up to 700 microns, made of a porous polymer contg. oxides, hydroxides or inorganic salts having high pore volumes and low solubility in KOH. The diaphragm has an ohmic resistance, measured in 10 N KOH at 110 deg.C., of at most 0.3 ohm/sq.cm., a porosity content greater than 50% with pore size of at most 1 micron, a tensile strength of at least 25 kg/sq.cm., a modulus of elasticity (Young's modulus) of at least 200 kg/sq.cm. and a burst strength of at least 3 kg/sq.cm. Specifically the (hydr)oxides or inorganic salts are those of alkali(ne earth) metals (e.g. Na, K, Ca and Mg), and metals of the Zr, Th and Ce gps. Preferred polymers for the diaphragm include PTFE, polysulphone, polyoxyphenylene. |
