Patent ID: 6124413
Filing Date: 2000-09-26
Classification: C07F,C08F

Abstract:
A process for preparing elastomeric ethylene-propylene (EPM) copolymers or elastomeric ethylene-propylene-diene (EPDM) terpolymers having a propylene content of from 15 to 75% by weight, comprising:(1) feeding propylene and, optionally, diene, to polmerization reactor under a pressure where the propylene is a liquid;(2) adding ethylene to the propylene;(3) adding a catalytic system which comprises(a) one or more metallocenes represented by formula (I): ##STR4## wherein M is zirconium;X is chlorine;A is a .eta..sup.5 -indenyl radical represented by formula (Ia) or a .eta..sup.5 -tetrahydroindenyl radical represented by formula (Ib): ##STR5## wherein R.sub.1 and R.sub.2, which may be the same or different from each other, are selected from the group consisting of H, aliphatic radicals, cycloaliphatic radicals, and aryl radicals,with the proviso that compounds in which A is represented by formula (Ia), R.sub.2 =H and R.sub.1 is different from --H in the 3-, 4- and 7-positions, are excluded, and(b) one or more co-catalysts selected from the group consisting of(i) compounds represented by the formula (IV) (Ra).sub.x NH.sub.4-x B(Rd).sub.4, compounds represented by the formula (V) (Ra).sub.3 PHB(Rd).sub.4, compounds represented by the formula (VI) B(Rd).sub.3, compounds represented by the formula (VII) (C.sub.6 H.sub.5).sub.3 CB(Rd).sub.4, optionally in the presence of an alkylating agent,wherein x is 1, 2, or 3,wherein each Ra is independently selected from the group consisting of monofunctional alkyl radicals and monofunctional aryl radicals, andwherein each Rd is independently a monofunctional aryl radical which may be partially or totally fluorinated,and(ii) alumoxanes;(4) polymerizing the propylene, the ethylene, and, optionally, the diene, for a time sufficient to produce a EP(D)M copolymer having a Mooney viscosity (ML.sub.1+4 at 100.degree. C.) higher than 20.