The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 1984
Filed:
Nov. 12, 1980
Jean-Louis Herisson, Brignais, FR;
Produits Chimiques Ugine Kuhlmann, Courbevoie, FR;
Abstract
The process for the polymerization in aqueous dispersion of tetrafluoroethylene in the presence of an emulsifier and an initiator, with the latter yielding free radicals between 0.degree. and 45.degree. C. and being destroyed for a temperature above 45.degree. C., characterized by the fact that the temperature of the reaction medium as a function of polymerization time is made to follow an ascending curve, Temperature .degree.C. versus t (time in minutes) whose slope (.DELTA.T/.DELTA.t) cannot be less than 1/6, .DELTA.T representing the temperature in .degree.C. at a given time in minutes .DELTA.t, with this ascending curve being situated inside of a sector limited by two straight lines y=(7/12)x and y=(15/7)x+45, in which y and x respectively represent the temperature in .degree.C. and the time expressed in minutes, and by the fact that the initiator is destroyed before the concentration of polytetrafluoroethylene in the dispersion has reached 20%.