Patent ID: 6878484
Filing Date: 2005-04-12
Classification: H01M,Y02E,Y10T

Abstract:
1. A secondary battery separator made of a resin composition mainly containing a polyolefin having at least one hydrophilic functional group, characterized in that the resin composition has a content (ratio to a total resin amount) of a low-density polyethylene of 20 mass % or less, a piercing strength of 5 to 100 N, a Metsuke of 20 to 75 g/m 2 , a thickness of 15 to 150 μm, and an unneutralized hydrophilic functional group amount of 1×10 −3 to 5×10 −2 mol/m 2 , which amount is defined as follows: unneutralized hydrophilic functional group amount (mol/m