Patent ID: 8293843

Claim:
A process for producing a polypropylene resin composition comprising 5-50% by weight of a component (I) defined below and 50-95% by weight of a component (III) defined below, the amounts in % by weight being on the basis of a total of the weight of the component (I) expressed by W I and the weight of the component (III) expressed by W III , wherein the process comprises a 1st step and a 2nd step each defined below: component (I): a propylene-α-olefin block copolymer (I) which comprises 2-65% by weight of a polymer portion (I-A) obtained by polymerizing, in a first stage, monomers mainly including propylene and 35-98% by weight of a polymer portion (I-B) obtained by polymerizing, in a second stage, propylene and α-olefin other than propylene, the amounts in % by weight being on the basis of the whole weight of the copolymer (I), wherein the content of the α-olefin contained in the polymer portion (I-B) is 10-50% by weight on the basis of the whole weight of the monomers contained in the polymer portion (I-B), and the intrinsic viscosity [η]B of the polymer portion (I-B) is not less than 4 dl/g but not more than 10 dl/g; component (III): a polymer (III) which is obtained by polymerizing monomers mainly including propylene and has an intrinsic viscosity [η] not less than 0.6 dl/g but not more than 3 dl/g; 1st step: a step of melt-kneading the component (I) of the amount of W I to produce a melt-kneaded material; 2nd step: a step of melt-kneading the component (III) of the amount of W III and the melt-kneaded material obtained in the 1st step together to produce a composition.