Patent ID: 6486276
Filing Date: 2002-11-26
Classification: C08F,Y10S

Abstract:
A process for the preparation of an elastomeric ethylene-propylene polymer wherein said process is characterized by being undertaken under solution polymerization conditions in the presence of a catalyst system which comprises:1) an unbridged catalyst having a single cyclopentadienyl ligand and a monosubstituted monoanionic nitrogen ligand; and 2) a boron activator; wherein said catalyst is defined by the formula: wherein Y is selected from the group consisting of: ai) a phosphorus substituent defined by the formula: wherein each R1 is independently selected from the group consisting of a hydrogen atom, a halogen atom, C1-20 hydrocarbyl radicals which are unsubstituted by or further substituted by a halogen atom, a C1-8 alkoxy radical, a C6-10 aryl or aryloxy radical, an amido radical, a silyl radical of the formula: â€ƒâ€”Siâ€”(R2)3 wherein each R2 is independently selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy radical, C6-10 aryl or aryloxy radicals, and a germanyl radical of the formula: â€”Geâ€”(R2â€²)3 wherein R2â€² is independently selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy radical, C6-10 aryl or aryloxy radicals, and a germanyl radical; and aii) a substituent defined by the formula: wherein each of Sub1 and Sub2 is independently selected from the group consisting of hydrocarbyls having from 1 to 20 carbon atoms; silyl groups, amido groups and phosphido groups; Cp is a ligand selected from the group consisting of cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl and substituted fluorenyl; X is an activatable ligand and n is 1 or 2 depending upon the valence of M and the valence of X; and M is a group 4 metal selected from the group consisting of titanium, hafnium and zirconium.