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:
Aug. 23, 2011
Filed:
Dec. 11, 2006
Kazuya Iidani, Tokyo, JP;
Daisuke Inagaki, Tokyo, JP;
Kazuya Iidani, Tokyo, JP;
Daisuke Inagaki, Tokyo, JP;
Asahi Kasei Chemicals Corporation, Tokyo, JP;
Abstract
The present invention provides a microporous polyolefin film having a thickness of 1 μm (inclusive) to 50 μm (inclusive), a porosity of 30% (inclusive) to 70% (inclusive), a piercing strength of 0.15 N/μm or more in terms of a film thickness of 1 μm, tensile strengths in the length direction (MD tensile strength) and the width direction (TD tensile strength) of 30 MPa or more each, a thermal shrinkage in the width direction (TD thermal shrinkage) of 1% or less at 65° C., and a thermal shrinkage ratio in the length to width direction (MD/TD thermal shrinkage ratio) of more than 2 at 65° C. A process for producing the microporous film and a nonaqueous electrolyte secondary battery using the film are also provided.