摘要 |
In a battery separator of microporous rubber containing a network of threads, e.g. of glass fibres, the threads extend in channels in the rubber material each having a cross-sectional area sufficiently large with respect to that of the thread within it to allow the threads, or the majority thereof, to slide with some friction in the channels without breaking due to stretching when the separator is bent. The separator is manufactured by first coating the threads of the network with a substance, e.g. albumin, an organic salt, carbohydrate material such as dextrine, natural resin, synthetic resin such as polystyrene, furfural resin, or a phenolic resin, a highly viscous liquid, e.g. glycerine, or a heavy mineral oil, or a fat, and is then impregnated with a latex dispersion which is gelled and then vulcanized, the initial coating substance being removed from the threads by melting, vaporization, or otherwise during the vulcanization to provide the aforesaid channels. Specification 739,069 [Group III] is referred to. |