Patent ID: 8575287
Filing Date: 2013-11-05
Classification: C08F,C08J

Abstract:
1. A method for producing a polytetrafluoroethylene fine powder, which comprises emulsion polymerizing tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator, to produce an aqueous polytetrafluoroethylene emulsion, and coagulating the emulsion in the presence of at least one bulk density-reducing compound selected from the group consisting of ammonium carbonate and ammonium hydrogencarbonate in an amount of from 0.4 to 10 parts by mass per 100 parts by mass of polytetrafluoroethylen, wherein the polytetrafluoroethylene fine powder produced is non-melt-moldable, has a standard specific gravity of from 2.140 to 2.150 and has a paste extrusion pressure of from 12 to 20 MPa.