| abstract |
The present invention discloses a microporous high-density polyethylene film for a battery separator, and process for preparing the same. The microporous high-density polyethylene film according to the present invention comprises of high-density polyethylene with weight average molecular weight of 2 x 105 ~ 4 x 105, containing not more than 5 wt% of molecules with molecular weight of 1 x 104 or less and not more than 5 wt% of molecules with molecular weight of 1 x 106 or more, and has the properties of puncture strength of 0.22 N/μm or more, Darcy's permeability constant of 1.8 x 10'5 Darcy or more, and shrinkage of 4% or less in machine and transverse direction, respectively. Particularly, the microporous high-density polyethylene film has excellent extrusion-compoundability and stretchability with high productivity and enhances performances and stability of the battery using the film. |