| 摘要 |
857,512. Batteries. YARDNEY INTERNATIONAL CORPORATION. April 9, 1957 [April 19, 1956], No. 12015/56. Class 53 A battery is provided with a separator made by hydrolysing a sheet of impermeable material to convert it into a semi-permeable state. The material may consist of polyvinyl acetate which may be formed as a film on a permeable carrier of nylon fabric by coating or impregnating the fabric with an emulsion of the acetate. After the carrier has been dried it is immersed in a solution of potassium or sodium hydroxide to hydrolyse the acetate to polyvinyl alcohol. The hydroxide solution may be the battery electrolyte. Instead of nylon the carrier may consist of rayon, paper or glass fibres. Alternatively the polyvinyl acetate may be in the form of a sheet which may contain plasticisers and which may be hydrolysed before or after it is incorporated in the battery. The final sheet of polyvinyl alcohol may be used in conjunction with other semi-permeable or porous materials such as regenerated cellulose and paper. The separator may be used in cells employing electrodes of silver and zinc, or of nickel and iron or cadmium. |
