| 摘要 |
1,255,247. Polymerization in sulphuric acid. VARTA A.G. 21 Aug., 1969 [24 Aug., 1968], No. 41831/69. Heading C3P. [Also in Divisions C1 and H1] A composition comprises a stable gel or solid mass containing concentrated sulphuric acid, the gel or solid comprising organic compounds polymerized in situ the gel or solid mass releasing sulphuric acid on treatment with water. The preferred organic compounds are acrylic acid or polymerizable acrylic acid derivatives (e.g. methacrylic acid or acrylamide). The compounds may be polymerized by the addition of one or more cross-linking agents e.g. methylene-bisacrylamide, methacrylic acid allyl ester, or cyanic acid triallyl ester. The composition may also contain an inert solid material which increases the porosity of the gel or solid, e.g. Kieselguhr. Before addition to the composition, the Kieselguhr may be saturated with sulphuric acid. The composition may be formed by forming a mixture of 3-10% by weight of acrylic acid or polymerizable acrylic acid derivative, a cross-linking agent and cone H 2 SO 4 and optionally a catalyst and polymerizing the mix to form a gel or solid mass. The sulphuric acid may have a concentration of 60- 95% by wt. The catalyst used may be peroxides or persulphates and 50-70% of Kieselguhr impregnated with cone H 2 S0 4 may be added to the mixture before polymerization. The composition may be attached to a support or supporting structure which support may be porous and impregnated with the composition. The article so formed may be enclosed by a microporous synthetic polymer sheet material. The composition may be used as the electrolyte of a lead acid accumulator. |
