| 摘要 |
PURPOSE: A polymerization method capable of providing a PTFE dispersion system having multi-modal or bi-modal grain diameter distribution by using a specific dosage system of two kinds of surfactants is provided. CONSTITUTION: The method is useful for preparing a tetrafluoroethylene(TFE) homopolymer/copolymer based dispersion system in which the distribution of particle diameters is two-modal or multi-modal. In this dispersion system, the small particle fraction occupies 1.5-35 mass % when calculated relative to the dry product and the small particle average diameter is 0.02-0.6 times the dispersed system average diameter resulting from polymerization. The preparation process of the dispersed system comprises that (a) an aqueous microemulsion is prepared comprising a fluoridated surface active agent and a (per) fluoropolymer oil (PFPE), (b) the microemulsion is supplied to a polymerization reactor, and (c) at least one fluoridated surface active agent is also supplied.
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