Use and production of polypropylene

Abstract

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 crystallisation 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 as described herein: R″(C p R 1 R 2 R 3 )(C p ′R n ′)MQ 2   (I)

1 - 10 . Cancelled.  
     
     
         11 . A process for producing an isotactic homopolymer of propylene with enhanced speed of solidification when solidified from a melt, having a melt temperature of from 139 to 144° C. and a difference between the melt temperature and the crystallisation temperature of not more than 50° C., the process comprising homopolymerising propylene in the presence of a metallocene catalyst of general formula:  
       R″(C p R 1 R 2 R 3 )(C p ′R n ′)MQ 2   (I)  
       wherein C p  is a substituted cyclopentadienyl ring; C p ′ is a substituted or unsubstituted fluorenyl ring; R″ is a structural bridge imparting stereorigidity to the component; R 1  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, a=2, and 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, R 2  is a substituent on the cyclopentadienyl ring which is proximal to the bridge and positioned non-vicinal to the distal substituent and is 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, R 3  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 0≦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.  
     
     
         12 . A process according to  claim 11  wherein R 1  is a methyl-cyclohexyl group.  
     
     
         13 . A process according to  claim 12  wherein R 2  is a methyl group.