| 摘要 |
PURPOSE: To obtain a polytetrafluoroethylene fine powder improved, for example, in such points that particle diameters are less scattered and the initial loss at the time of extrusion is less, by stirring an aqueous dispersion of a polytetrafluoroethylene under specified conditions to cause coagulation. CONSTITUTION: This polytetrafluoroethylene fine powder is produced by stirring an aqueous dispersion of a polytetrafluoroethylene in the presence of a water- insoluble organic solvent at a temperature equal to or lower than the room temperature transition point of the polytetrafluoroethylene to cause coagulation. Preferably, the aqueous dispersion of a polytetrafluoroethylene is stirred at a temperature in the range from 10 deg.C or more to that equal to or lower than the room temperature transition point of the polytetrafluoroethylene to cause coagulation. More preferably, the aqueous dispersion of a polytetrafluoroethylene is stirred at a temperature in the range of 10 to 25 deg.C to cause coagulation. |
