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:
Sep. 10, 2013
Filed:
Nov. 16, 2009
Katsuo Naoi, Tokyo, JP;
Kenji Nishizawa, Tokyo, JP;
Mitsuo Kougo, Tokyo, JP;
Yoshihiko Ohashi, Tokyo, JP;
Hidetake Itoh, Tokyo, JP;
Katsuo Naoi, Tokyo, JP;
Kenji Nishizawa, Tokyo, JP;
Mitsuo Kougo, Tokyo, JP;
Yoshihiko Ohashi, Tokyo, JP;
Hidetake Itoh, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A lithium-ion secondary battery separator has a porous structure formed by laminating a second polymer layer, a first polymer layer, and a second polymer layer in sequence. The second polymer layer has a melting point lower than that of the first polymer layer. The second polymer layer has a higher molecular part formed on a side in contact with the first polymer layer and a lower molecular part formed on a side farther from the first polymer layer than is the higher molecular part. The higher and lower molecular parts have a weight-average molecular weight ratio (higher molecular part/lower molecular part) of 4 to 19 therebetween.