| abstract |
A polyethylene multi-layer porous membrane comprising at least two layers, which membrane comprises (a) a polyethylene resin porous layer (A) containing a high-density polyethylene (A) having at least 0.2 terminal vinyl group per 10,000 carbon atoms as determined by infrared spectroscopy and (b) a polyethylene resin porous layer (B) containing a high-density polyethylene (B) having less than 0.2 terminal vinyl group per 10,000 carbon atoms as determined by infrared spectroscopy. This membrane is excellent in the balance among permeability, mechanical strengths, resistance to heat shrinkage, shut-down characteristics, meltdown characteristics, and oxidation resistance. |