POLYETHYLENE MICROPOROUS FILM AND PROCESS FOR PRODUCING THE SAME

摘要

A polyethylene microporous film excellent in mechanical strength, permeability and productivity and having a very high reliability such that the safety of a battery may be secured even under severe circumstances which film has a crosslinked structure and has a porosity of 20 - 80%, a gel fraction of 1% or more, and an average pore diameter determined by the permeation method of 0.001 - 0.1 .mu.m, and a process for producing the poly-ethylene microporous film.