Patent ID: 6107431
Filing Date: 2000-08-22
Classification: C07C,C08F,Y10S

Abstract:
A process for the preparation of a propylene polymer, the propylene polymer being a fractionable propylene polymer, directly obtainable from the polymerization reaction of propylene, having the following characteristics:(a) content of isotactic pentads (mmmm) comprised between 25% and 85%;(b) ratio M.sub.w /M.sub.n,<5;said polymer containing from 10% to 70% by weight based on the total weight of said polymer of a fraction soluble in boiling diethylether, said fraction having a content of isotactic pentads (mmmm) comprised between 5% and 25%, and from 30% to 90% by weight based on the total weight of said polymer of a boiling-heptane-insoluble fraction, which is soluble in xylene at 135.degree. C., said fraction having a content of isotactic pentads (mmmm) comprised between 50% and 99%;the process comprising comprising the polymerization reaction of propylene, in a polymerization medium consisting essentially of liquid propylene, in the presence of a catalyst comprising the product of the reaction between:(A) a metallocene compound of formula (1): ##STR6## wherein on each indenyl group the R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and R.sup.7 substituents, same or different from each other, are hydrogen atoms, C.sub.1 -C.sub.20 alkyl radicals, C.sub.3 -C.sub.20 cycloalkyl radicals, C.sub.2 -C.sub.20 alkenyl radicals, C.sub.6 -C.sub.20 -aryl radicals, C.sub.7 -C.sub.20 alkylaryl radicals, or C.sub.7 -C.sub.20 arylalkyl radicals, optionally two adjacent R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and R.sup.7 substituents on the same ring can form a cycle comprising 5 to 8 carbon atoms and, furthermore, substituents R.sup.1 can contain Si or Ge atoms;M is a transition metal of group IVb, Vb, or VIb of the Periodic Table of the Elements;substituents X, the same or different from each other, are hydrogen atoms, halogen atoms, --R.sup.8, --OR.sup.8, --SR.sup.8, NR.sup.8.sub.2, or --PR.sup.8.sub.2 groups, wherein substituents R.sup.8 are C.sub.1 -C.sub.20 alkyl radicals, C.sub.3 -C.sub.20 cycloalkyl radicals, C.sub.2 -C.sub.20 alkenyl radicals, C.sub.6 -C.sub.20 -aryl radicals, C.sub.7 -C.sub.20 alkylaryl radicals, or C.sub.7 -C.sub.20 arylalkyl radicals, and can contain Si or Ge atoms; and(B) an alumoxane, or one or more compounds able to give a metallocene alkyl cation.