MICROPOROUS POLYETHYLENE FILM HAVING EXCELLENT PHYSICAL PROPERTIES, PRODUCTIVITY, AND QUALITY CONSISTENCY, AND METHOD OF PRODUCING SAME

摘要

Disclosed herein is a microporous polyethylene film for a battery separator and a method of producing the same. The microporous polyethylene film is made from a resin composition. The resin composition comprises 100 parts by weight of a polyethylene composition including 10-50 wt % polyethylene having a weight average molecular weight of from 2x10⁵ to less than 5x10⁵ (component I) and 90-50 wt % diluent (component II), and 0-150 parts by weight of inorganic powder (component III). The film has a puncture strength of 0.20 N/mum or more and a gas permeability (Darcy's permeability constant) of 1x10^-5 Darcy or more. The microporous polyethylene film has excellent physical properties, thus improving the performance and stability of a battery.