Use and production of polypropylene

摘要

Use of isotactic polypropylene homopolymers or copolymers in processes in which the polypropylene solidifies from a melt, wherein for enhanced speed of solidification of the polypropylene the polypropylene has a melt temperature and a crystallization temperature not more than 50° less than the melt temperature resulting from the polypropylene having been produced using a metallocene catalyst component having the general formula:R''(C pR1R2R3)(Cp'Rn')MQ2 (I)wherein Cp is a substituted cyclopentadienyl ring; Cp' is a substituted or unsubstituted fluorenyl ring; R'' is a structural bridge imparting stereorigidity to the component; R1 is a substituent on the cyclopentadienyl ring which is distal to the bridge, which distal substituent comprises a bulky group of the formula XR*a in which X is chosen from Group IVA, and when a=3 each R* is the same or different and chosen from hydrogen or hydrocarbyl of from 1 to 20 carbon atoms, or when a=2 one R* is chosen from hydrogen or hydrocarbyl of from 1 to 20 carbon atoms and the other different R* is chosen from a substituted or unsubstituted cycloalkyl where X is a carbon atom in the cycloalkyl ring, R2 is a substituent on the cyclopentadienyl ring which is proximal to the bridge and positioned non-vicinal to the distal substituent and is hydrogen or of the formula YR#3 in which Y is chosen from Group IVA, and each R# is the same or different and chosen from hydrogen or hydrocarbyl of 1 to 7 carbon atoms, R3 is a substituent on the cyclopentadienyl ring which is proximal to the bridge and is a hydrogen atom or is of the formula ZR$3 in which Z is chosen from Group IVA, and each R$ is the same or different and chosen from hydrogen or hydrocarbyl of 1 to 7 carbon atoms, each R'n is the same or different and is hydrocarbyl having 1 to 20 carbon atoms in which O<=n<=8; M is a Group IVB transition metal or vanadium and each Q is hydrocarbyl having 1 to 20 carbon atoms or is a halogen.