Patent · US Expired

Modified polytetrafluoroethylene fine powder and production of the same

US4840998A · kind A · utility

26Cited by
7References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 27, 1987
Grant dateJun 20, 1989
Priority date
Expiry dateAug 27, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S525/902
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

Modified PTFE fine powder which comprises primary particles having an average particle size of 0.1 to 0.6 .mu.m and contains 0.01 to 0.15% by weight, based on the total weight of the particles, of at least one olefinically unsaturated compound selected from the group consisting of a fluoroalkyl vinyl ether of the formula: EQU X(CF.sub.2).sub.n OCF.dbd.CF.sub.2 (I) wherein X is a hydrogen atom, a fluorine atom or a chlorine atom and n is an integer of 1 to 6, and a fluoroalkyl vinyl ether of the formula: EQU C.sub.3 F.sub.7 (OCF.sub.2 CF.sub.2 CF.sub.2).sub.m [OCF(CF.sub.3)CF.sub.2 ].sub.l OCF.dbd.CF.sub.2 (II) wherein m is an integer of 0 to 2 and l is an integer of 0 to 2 mainly in core parts of the particles and 0.04 to 0.25% by weight, based on the total weight of the particles, of chlorotrifluoroethylene in shell parts, which has good paste extrudability and heat stability.

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