| 摘要 |
Strong fibres are obtained by depositing a thin narrow stream of a latex of an unplasticised and normally crystalline polymer or copolymer of a vinylidene halide or cyanide on a smooth, non-absorptive surface, drying the filamentary deposit, stripping it from the surface, heating it to a fusion temperature, chilling it and stretching the supercooled filament to effect orientation and crystallization. The latex is an aqueous dispersion of a polymer of vinylidene chloride, bromide, cyanide, chlorobromide, chlorocyanide or bromocyanide, or a copolymer thereof with one another or with minor amounts of other monoethylenically unsaturated compounds such as vinyl chloride, vinyl bromide, vinyl acetate, acrylonitrile, methacrylonitrile, styrene, chlorostyrene, and methyl or ethyl acrylates or methacrylates, and is made by emulsion polymerization, the polymeric particles being temporarily amorphous when first formed and being substantially all under 1000 in diameter. The dispersion is deposited while a substantial proportion of the polymer is still non-crystalline, deposition being effected by discharging the dispersion through a stylus or from the periphery of a thin driven disc on to a smooth moving belt or rotating drum. Drying of the deposit may be effected by infra-red lamps, by heat conducted through the smooth surface or by circulating warm air.
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