Patent ID: 11967733
Assignee: PANASONIC ENERGY CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B  Y | IPC B  H

Claim 0:
1. A nonaqueous electrolyte secondary battery separator comprising a porous polyolefin substrate and a heat resistant layer disposed on a side of the substrate, wherein
the heat resistant layer comprises an aramid resin,
the aramid resin has a ratio (B/A) of 0.94 to 1.14 wherein A is the absorbance at a wavelength of 1318 cm−1 and B is the absorbance at a wavelength of 1650 cm−1 in an infrared absorption spectrum obtained by infrared spectroscopic measurement, and
wherein the aramid resin is a copolymer containing a para-aramid skeleton and a meta-aramid skeleton.