Ethylene elastomer compositions

摘要

In a process for producing an elastomer composition, ethylene, at least one alpha-olefin, and at least one diene is contacted with a catalyst system comprising at least one metallocene catalyst compound and a non-coordinating anion activator. The at least one metallocene catalyst compound comprises an indenyl complex having the general formula: (In¹R¹_m)R³(In²R²_p)MX_q; wherein the or each R¹ is a substituent of the indenyl ring In¹ and the or each R² is a substituent of the indenyl ring In², each R¹ and R² is, independently, a halogen or a hydrocarbyl, halocarbyl, hydrocarbyl-substituted organometalloid or halocarbyl-substituted organometalloid group containing up to about 20 carbon atoms, and at least one R¹ or R² substituent is bonded to the 2-position or the 4-position of its associated indenyl ring; m is 1 to 6; p is 1 to 6; R³ is a bridging group, such that the number of atoms in the direct chain between the (In¹R¹_m) ligand and the (In²R²_p) ligand is 1 to 8, M is a transition metal from Group 3, 4, 5 or 6 of the Periodic Table of the Elements, or an actinide or lanthanide metal atom; q is equal to the valence of M minus 2; and each X is a non-cyclopentadienyl ligand and is, independently, a hydrocarbyl, oxyhydrocarbyl, halocarbyl, hydrocarbyl-substituted organometalloid, oxyhydrocarbyl-substituted organometalloid or halocarbyl-substituted organometalloid group containing up to about 20 carbon atoms; provided that two X groups may be joined and bound to the metal atom to form a metallacycle ring containing from about 3 to about 20 carbon atoms; or two X groups together can be an olefin, diolefin or aryne ligand.