PRODUCTION OF AQUEOUS DISPERSION CONTAINING POLYTETRAFLUOROETHYLENE

摘要

PROBLEM TO BE SOLVED: To produce the subject dispersion capable of providing a fine powder affording a drawn porous material having excellent uniformity by secondary fabrication by polymerizing tetrafluoroethylene in the presence of a specific surfactant in an aqueous medium. SOLUTION: Tetrafluoroethylene is polymerized in the presence of a surfactant selected from a compound represented by formula I or II [(n) is 8-11; (m) is 0-2; X is COOM or SO3 M (M is an alkali metal ion or ammonium ion); Y is COOM] in an aqueous medium to produce the objective dispersion. C9 F19 COONH4 is preferred as the surfactant represented by formula I and C3 OCF(CF3 ) CF2 OCF(CF3 )COONH4 is preferred as the surfactant represented by formula II. The C3 F7 group is preferably linear. The polytetrafluoroethylene in the resultant dispersion is flocculated to afford a powdery polytetrafluoroethylene fine powder.