| 摘要 |
The purpose of the present invention is to provide a method in which a polytetrafluoroethylene (PTFE) aqueous dispersion having an extremely small PTFE particle size and exhibiting excellent dispersion stability can be produced using multi-stage polymerization, even without using long-chain fluorine-containing surfactants. This production method for a PTFE aqueous dispersion includes: a step (1) in which polymerization of a fluoromonomer is performed in an aqueous medium in the presence of a fluorine-containing surfactant and a polymerization initiator, to produce an aqueous dispersion including fine particles of at least one fluoropolymer selected from the group consisting of PTFE and melt-fabricable fluorine resins (other than PTFE); and a further step (2) in which polymerization of either tetrafluoroethylene (TFE), or, TFE and a modified monomer is performed in an aqueous medium in the presence of a polymerization initiator and the fluoropolymer fine particles, to produce an aqueous dispersion including PTFE particles. The fluoropolymer fine particles have an equivalent weight (EW) of at least 6,000, and a volume average particle size of at least 0.1 nm but less than 20 nm. |
