Polypropylene composition for lithium ion battery separator

Conventional secondary battery when the membrane material for multi are mainly used for kneading, the pore-forming manner by the process of extrusion and stretching with a diluent in the pore size of the diluent has a melting rate and molecular weight of the solvent determines the porosity factor as the action has a problem in having a pore structure, the surface and inside uniformly failed. The invention (a) stereoregularity of 97% or more homopolymer polypropylene 90 ~ 99.5% by weight and (b) a polypropylene resin with 0.5 to 10% by weight of the blend having a polar structure, stretched at 100 ~ 180 ℃ for the secondary battery separators having a poly-domain structure provides a propylene resin composition.