| 摘要 |
A microporous battery separator comprises a mass of partially coalesced synthetic resin particles, said mass containing from 40 to 55 per cent intercommunicating voids. Specified resins are the polymers of styrene, acrylonitrile, vinylbromide, and ethylene, their copolymers with each other or with butadiene or vinyl naphthalene. Preferred resins however are the polymers of vinyl chloride and vinylidene chloride, the copolymer thereof and copolymers of either with minor amounts of vinyl fluoride, acrylonitrile or styrene. Preferably from 0.1 to 30 per cent of a liquid plasticizer, e.g. tricresyl phosphate, is also present and may be allowed to remain in the finished product or removed by the heating step or by extraction with solvent. The separator may be made by continuously shaping a body of synthetic resin particles to the desired configuration by rolling pressure, and continuously advancing the body through a heating zone to heat it to a temperature sufficient to sinter the particles. |
