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:
Jun. 08, 2021
Filed:
May. 31, 2019
Sumitomo Chemical Company, Limited, Tokyo, JP;
Tomoaki Ozeki, Niihama, JP;
SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo, JP;
Abstract
A nonaqueous electrolyte secondary battery separator is provided in which thickness unevenness caused by wrinkles is reduced. The nonaqueous electrolyte secondary battery separator includes a polyolefin porous film, and when a test piece cut out from the nonaqueous electrolyte secondary battery separator is immersed in propylene carbonate, the test piece exhibits an elongation percentage difference of not more than 0.20%; the elongation percentage difference being a difference between (i) an elongation percentage in a longitudinal direction of the test piece as observed after 30 minutes of immersion in propylene carbonate and (ii) an elongation percentage in the longitudinal direction of the test piece as observed after 24 hours of immersion in propylene carbonate.