Patent ID: 6913834

Claim:
A polyolefin base resin composition (A) comprising [I] a 1-butene base polymer in an amount of 1 to 99% by weight, [II] a propylene base resin in an amount of 99 to 1% by weight and a nucleus-forming agent in an amount of 10 ppm or more, wherein [I] the 1-butene base polymer satisfies the following requirements (1) to (4): (1) it is a crystalline resin having a melting point (TmD) of 0 to 100° C. defined as a peak top in a peak observed at the highest temperature side in a melt endothermic curve which is obtained by holding a sample at −10° C. for 5 minutes under a nitrogen atmosphere by means of a differential scanning type calorimeter (DSC) and then elevating the temperature at a rate of 10° C./minute; (2) a stereospecific index [(mmmm)/(mmrr+rmmr)] is 20 or less; (3) a molecular weight distribution (Mw/Mn) determined by gel permeation chromatograph (GPC) is 4.0 or less; and (4) a weight average molecular weight (Mw) determined by GPC is 10,000 to 1,000,000.