| abstract |
Unique combination of high molecular weight (Mw), rubbery viscosity (ML 1 + 4 , 125 ℃), low polydispersity index (Mw / Mn), low glass transition temperature (Tg) and low hysteresis (tan δ) Polyolefin elastomers are prepared by a method of polymerization using a particular type of metallocene catalyst. Polyolefin elastomers are useful in the manufacture of a variety of products including rubber articles such as hoses, belts and moldings, polymer blends containing one or more other hydrocarbon polymers, and lubricants in which the elastomer acts as a viscosity modifier. Also disclosed are cation-producing promoters for activating the metallocene procatalyst, preferably in the presence of an olefin monomer. |