Propylene elastomer

摘要

A transition metal compound of formula (I): wherein M is a transition metal of Group IVa, Group Va and Group VIa of the periodic table; R<1> and R<2>, which may all be identical or different from each other, are each a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group; R<3> is an alkyl group of 2 to 20 carbon atoms; R<4> is an alkyl group of 1 to 20 carbon atoms; X<1> and X<2>, which may be identical or different, are each a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group or a sulfur-containing group; and Y is a divalent hydrocarbon group of 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group of 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group, a divalent tin-containing group, -O-, -CO-, -S-, -SO-, -SO2-, -NR<5>-, -P(R<5>)-, -P(O)(R<5>)-, -BR<5>- or -AlR<5>-, wherein R<5> is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms or a halogenated hydrocarbon group of 1 to 20 carbon atoms.