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. 04, 2025
Filed:
Jul. 08, 2022
Daikin Industries, Ltd., Osaka, JP;
Chisato Iguchi, Osaka, JP;
Eiji Masuda, Osaka, JP;
Masayuki Tsuji, Osaka, JP;
Akira Shimodo, Osaka, JP;
Jirou Hiromoto, Osaka, JP;
Shigeki Santou, Osaka, JP;
DAIKIN INDUSTRIES, LTD., Osaka, JP;
Abstract
A method for producing low-molecular-weight polytetrafluoroethylene containing a reduced amount of C4-C16 perfluorocarboxylic acids and salts thereof, as well as a powder containing low-molecular weight polytetrafluoroethylene, the method including (1) irradiating polytetrafluoroethylene containing a C4-C16 perfluorocarboxylic acid or any salt thereof and having a heat-of-fusion reduction of 40% or lower between first heating and second heating in differential scanning calorimetry with radiation to a dose of 5 to 1000 kGy substantially in the absence of oxygen at a temperature of lower than 100° C. to provide low-molecular-weight polytetrafluoroethylene containing a reduced amount of the perfluorocarboxylic acid and any salt thereof and having a melt viscosity at 380° C. of 1.0×10to×10Pa·s.