Patent ID: 6939929

Claim:
A process for producing an atactic α-olefin-aromatic vinyl compound copolymer, the process comprising copolymerizing in a temperature range of 50-200° C. an α-olefin with an aromatic vinyl compound in the presence of a polymerization catalyst comprising a transition metal compound (A) and a promoter catalyst component (B), wherein the atactic α-olefin-aromatic vinyl compound copolymer comprises: (I) the α-olefin, and (II) 0.1 to 90 mole % of the aromatic vinyl compound, wherein the atactic α-olefin-aromatic vinyl compound copolymer has a molecular weight distribution measured by a GPC method of 3.0 or less, wherein in a 13 C-NMR measurement the following signals are present: a signal (Sββ) based on an (aromatic vinyl compound-olefin-olefin) chain, a signal (Sββ) based on an (aromatic vinyl compound-olefin-aromatic vinyl compound) chain, a signal (Tββ) based on a blocking (aromatic vinyl compound-aromatic vinyl compound-aromatic vinyl compound) chain in the aromatic vinyl compound, and a signal (Sββ) based on a blocking (olefin-olefin-olefin) chain in the olefin part; wherein an index (θ) showing a blocking property of the aromatic vinyl compound component which is represented by the following relational equation is 10 to 80%: θ= I ( Tββ+T βδ)/[ I ( Tδδ+TγδTββ+T βδ)]×100, wherein I(Tββ+Tβδ) represents the sum of the intensities of the signals Tββ and Tβδ in the 13 C-NMR measurement, provided that Tβδ represents a signal based on an (aromatic vinyl compound-aromatic vinyl compound-olefin) chain; and I(Tδδ+Tγδ+Tβδ) represents the sum of the respective intensities of the signals Tδδ, Tγδ, Tββ and Tβδ based on all chains in which the aromatic vinyl compound participates among the chains of the above copolymer in the 13 C-NMR measurement, Tδδ represents a signal based on an (olefin-aromatic vinyl compound-olefin) chain, and Tγδ represents a signal based on a heterogeneous bond of an (aromatic vinyl compound-aromatic vinyl compound-olefin-olefin) chain or a signal based on a heterogeneous bond of an (aromatic vinyl compound-olefin-aromatic vinyl compound-olefin) chain, wherein the component (A) in the polymerization catalyst is a transition metal compound Formula (1): wherein A 1 and A 2 each represent independently a cyclopentadienyl group, or a substituted cyclopentadienyl group; Y 1 represents propylidene group; Y 2 represents dimethylsilylene group; M 1 represents titanium, zirconium or hafnium; and X 1 and X 2 each represent independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or an aryloxy group.