METHOD FOR PRODUCING POLYTETRAFLUOROETHYLENE FINE POWDER
First Claim
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 it in the presence of at least one bulk density-reducing compound selected from the group consisting of ammonia, an ammonium salt and urea in an amount of from 0.4 to 10 parts by mass per 100 parts by mass of polytetrafluoroethylene.
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Abstract
To provide a method for producing a PTFE fine powder having a low paste extrusion pressure property by a simple method.
The method for producing a PTFE fine power comprises emulsion polymerizing tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator, to produce an aqueous PTFE emulsion, and coagulating it in the presence of at least one bulk density-reducing compound selected from the group consisting of ammonia, an ammonium salt and urea in an amount of from 0.4 to 10 parts by mass per 100 parts by mass of PTFE.
24 Citations
10 Claims
- 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 it in the presence of at least one bulk density-reducing compound selected from the group consisting of ammonia, an ammonium salt and urea in an amount of from 0.4 to 10 parts by mass per 100 parts by mass of polytetrafluoroethylene.
Specification