Polyolefin resin compositions and use thereof

The present invention, mechanical properties, excellent dimensional stability, provides a polyolefin resin composition particularly excellent in heat resistance, and, by obtained from the polyolefin resin composition, mechanical properties, dimensional stability, heat resistance excellent, it is that particularly good film meltdown properties, and in addition to the above properties, to provide transparency and microporous membrane excellent in shutdown properties, and their uses. Polyolefin resin composition (C) of the present invention, the polyolefin resin composition (C) in 100 mass%, and 85-50 wt% ultra high molecular weight polyethylene (A) having a specific intrinsic viscosity, 4-methyl-1 - characterized in that it comprises a polymer (B) and 15 to 50 wt% comprising repeating units derived from pentene.