Patent ID: 7276558

Claim:
A polymer composition comprising: from 70 to 99% by weight of a polymer (A) satisfying Requirements (A-1) through (A-3) defined below and from 1 to 30% by weight of a polymer (B) satisfying Requirements (B-1) and (B-2) defined below, the polymer composition satisfying Requirements (1) and (2) defined below, wherein said amounts of the polymers (A) and (B) are based on a combined amount of the polymers (A) and (B): Requirement (1): the content of a 20° C. xylene-soluble portion of the polymer composition is from 5 to 45% by weight, Requirement (2): a 20° C. xylene-soluble portion of the polymer composition has an intrinsic viscosity of 1.3 dl/g or higher, Requirement (A-1): the polymer is a copolymer of propylene and α-olefin having 4 or more carbon atoms or a copolymer of propylene, α-olefin having 4 or more carbon atoms and ethylene, Requirement (A-2): the polymer has a content of structural units derived from α-olefin having 4 or more carbon atoms of from 3 to 40% by weight, Requirement (A-3): the polymer has a content of structural units derived from ethylene of from 0.1 to 5% by weight when the polymer is a copolymer of propylene, α-olefin having 4 or more carbon atoms and ethylene, Requirement (B-1): the polymer is a homopolymer of 1-butene, a copolymer of 1-butene and ethylene, a copolymer of 1-butene and propylene, a copolymer of 1-butene and α-olefin having 4 or more carbon atoms other than 1-butene, a copolymer of 1-butene, ethylene and propylene or a copolymer of 1-butene, ethylene and α-olefin having 4 or more carbon atoms other than 1-butene, and Requirement (B-2): the polymer has a melting point of not lower than 60° C. but lower than 125° C., and wherein polymer (A) is a polymer containing from 1 to 30% by weight of a segment (a-1) defined below and from 70 to 99% by weight of a segment (a-2) defined below, wherein the amounts of the segments are based on the combined weight of the segments: segment (a-1): a segment having structural units derived from 1-butene in a content of not less than 1% by weight but less than 15% by weight, segment (a-2): a segment having structural units derived from 1-butene in a content of not less than 15% by weight but not more than 40% by weight.