Ethylene polymer useful as a lubricating oil viscosity modifier

摘要

An ethylene ter- or tetrapolymer useful as a viscosity modifier and a process for preparing the polymer. The polymer comprises ethylene, an alpha-olefin, a non-conjugated diene and, optionally, a cationically polymerizable monoolefin. The polymerization catalyst comprises a Ziegler catalyst in conjunction with a cationic polymerization catalyst.