MULTI-LAYERED MICRO-POROUS POLYOLEFIN FILM HAVING EXCELLENT THERMAL PROPERTY AND METHOD FOR PREPARING THE SAME

摘要

PURPOSE: A polyolefin-based composite microporous membrane is provided to minimize moisture content, to simplify processes, to improve stability, and to obtain heat resistance and high transmittance. CONSTITUTION: A polyolefin-based composite microporous membrane is formed by spreading or laminating a polymer binder and inorganic particles on a microporous membrane substrate. The polymer binder is in an aqueous solution state at 20°C and 0.5 wt% and simultaneously comprises 50-90 wt% of a non-soluble polymer which has a glass transition temperature(Tg) of -60 to 0 °C, and 50-10 wt% of a water-soluble polymer which has a glass transition temperature of 200 °C or more and a surface tension of 65 dyne/cm or less. The non-soluble polymer comprises one or more of styrene acrylics, styrene butadiene, acrylics, and vinyl acrylics.