MIKROPORÖSE FOLIE AUS POLYETHYLEN HOHER DICHTE UND HERSTELLUNGSVERFAHREN DAFÜR

摘要

Provided are a microporous high density polyethylene film, which is easily extruded and drawn, has a high Darcy's permeability constant, good tensile strength, superior punching strength, and low shrinkage, and is useful for battery separators or various filters, and a preparation thereof. The microporous high density polyethylene film is prepared from a composition consisting of 20-50wt% of a high density polyethylene(component I) and 80-50wt% of a diluent(component II), and has a tensile strength in a lengthwise direction and in a widthwise direction of 1,100kg/cm^2 or more, a punching strength of 0.22N/micron or more, a Darcy's permeability constant of 1.3Î10^(-5) Darcy or more, and a shrinkage in a lengthwise direction and in a widthwise direction of 5 % or less. The high density polyethylene(component I) has a weight average molecular weight of 2Î10^5 to 5Î10^5 and contains at least 5wt% of the polymer with a molecular weight of 1Î10^4 or less.