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:
Oct. 06, 1992
Filed:
Jul. 11, 1991
Applicant:
Inventors:
Bernd Felix, Burgkirchen, DE;
Gernot Lohr, Burgkirchen, DE;
Willibald Hofmeister, Burgkirchen, DE;
Rolf Hengel, Burgkirchen, DE;
Assignee:
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08F / ; C08F / ;
U.S. Cl.
CPC ...
526206 ; 526236 ; 526247 ; 526249 ; 526255 ;
Abstract
In the suspension polymerization of tetrafluoroethylene a mixture of tetrafluoroethylene and an inert gas is charged under pressure before starting the polymerization, the total pressure being 5 to 50 bar and the concentration of tetrafluoroethylene in this mixture being 30 to 70 mol %. Said concentration is kept within this range by an appropriate feed of tetrafluoroethylene during the polymerization. The granular PTFE powder obtained is distinguished by an improved grain structure and grindability.