Patent · US Expired

Modified tetrafluoroethylene polymer and process for producing same

US4134995A · kind A · utility

10Cited by
3References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 2, 1978
Grant dateJan 16, 1979
Priority date
Expiry dateFeb 2, 1998

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08F259/08
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

In a process for polymerization of tetrafluoroethylene with a copolymerizable modifier in an aqueous medium containing a polymerization initiator and a dispersant to produce a modified tetrafluoroethylene polymer containing 0.001 to 2 wt.% of the copolymerizable modifier based on the weight of the polymer, a process for producing the modified tetrafluoroethylene polymer characterized in that: PA1 (1) chlorotrifluoroethylene is used as said copolymerizable modifier, PA1 (2) at least 50 wt.% of the copolymerizable modifier to be incorporated into the polymer is introduced into the polymerization system after 70 wt.% of the polymer to be finally formed has been formed, and PA1 (3) after 90 wt.% of the polymer to be finally formed has been formed, the concentration of said copolymerizable modifier is maintained at at least 0.01 mol.% based on the total amount of tetrafluoroethylene and the modifier in the polymerization system.

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