Patent ID: 7858714

Claim:
A process for producing polypropylene polymer, comprising: mixing together a diluent containing more than 10 weight percent of a fluorinated hydrocarbon based on the total weight of the diluent, a Ziegler-Natta catalyst system, and an olefin feed containing at least 90 weight % propylene and less than 10 weight % ethylene, based on total weight of the feed, and forming a polypropylene polymer having a melting temperature equal to or greater than 85° C., wherein the polymerization is carried out at a temperature of from greater than 30° C. to 160° C. and provided when the catalyst is TiCl 4 combined with an aluminum alkyl, the fluorinated hydrocarbon is a hydrofluorocarbon, wherein Ziegler-Natta catalyst system comprises a catalyst compound and an activator compound and when the activator compound is an organic aluminum compound, the organic aluminum compound is represented by the formula R n AlX 3-n , where R is an alkyl group or an aryl group having from 1-18 carbon atoms, X is an alkoxy group or a hydrogen atom, and n is a number in the range of 1 to 3.