To provide a process for producing a PTFE molding powder having a high bulk density from granular polymer particles without using an emulsifying agent having problems of bioaccumulation and toxicity.
A process for producing a polytetrafluoroethylene molding powder, which comprises a step of suspension-polymerizing a monomer containing at least 99.8 mass% of tetrafluoroethylene in an aqueous medium to produce granular polymer particles and a step of milling the granular polymer particles, wherein the aqueous medium contains a compound represented by RF(OCF(X1)CF2)k-1OCF(X2)COO-M+, at a concentration of from 0.5 to 2,000 ppm. RF is a perfluorinated C1-10 monovalent organic group, X1 and X2 are fluorine atoms, etc., and M+ is an ammonium ion or the like.
提供一种无需使用具有
生物蓄积性和毒性问题的
乳化剂,即可从粒状聚合物颗粒中生产出具有高堆积密度的聚
四氟乙烯模塑粉的工艺。
一种生产聚
四氟乙烯模塑粉的工艺,包括在
水介质中悬浮聚合含有至少 99.8 质量%的
四氟乙烯的单体以生产粒状聚合物颗粒的步骤,以及碾磨粒状聚合物颗粒的步骤,其中
水介质含有 RF(OCF(X1)
CF2)k-1OCF(X2)COO-M+ 代表的化合物,浓度为 0.5 至 2,000 ppm。RF 是
全氟 C1-10 单价有机基团,X1 和 X2 是
氟原子等,M+ 是
铵离子等。