Patent · US Expired

Process for preparation of polytetrafluoroethylene molding powder

US6054083A · kind A · utility

3Cited by
5References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 12, 1997
Grant dateApr 25, 2000
Priority date
Expiry dateSep 12, 2017

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08J2327/18
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A preparation process in which PTFE coarse particles are finely pulverized into particles in wet state, thus enabling the finely pulverized particles to be washed as they are and an amount of impurities to be decreased efficiently and after the washing, agglomeration granulation is carried out, thus enabling PTFE molding powder to be obtained in the reduced number of steps; a preparation process of a polytetrafluoroethylene molding powder, characterized in that polytetrafluoroethylene coarse particles obtained by suspension polymerization of tetrafluoroethylene are finely pulverized, in wet state, into an average particle size particularly in a range of 10 to 100 .mu.m and then washed; and a preparation process of a polytetrafluoroethylene molding powder, characterized in that after the washing, mechanical force is applied to the washed powder in wet state for agglomeration granulation, thus giving particles having an average particle size in a range of 200 to 800 .mu.m.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.