MICROPOROUS POLYOLEFIN MULTI LAYER FILM AND PREPARING METHOD THEREOF

摘要

A microporous polyolefin multi-layer film is provided to ensure low closing temperature characteristic and high melt fracture temperature characteristic, uniform micro pores and highly-rigid/stability, and high permeabilty/high-strength property. A method for manufacturing a microporous polyolefin multi-layer film comprises the steps of: (i) melt-kneading a composition consisting of polyethylene 20~50 wt% having a melting point of 125 °C or more and diluent 80~50 wt%; (ii) melt-kneading a composition consisting of polypropylene 20-70 wt% having a melting point of 160 °C or more and heat-resistant filler 80-30wt%; (iii) molding molten materials in steps (i) and (ii) to become 2-3 layers; (iv) drawing the multilayer sheet to form a film; (v) extracting diluent from the film; and (vi) heat-setting the film.