Catalysts for the polymerization of olefins

Claim 1

A catalyst for the polymerization of olefins comprising the product obtained by contacting the following components: (A) a cyclopentadienyl compound of the formula (I): (C.sub.5 R.sup.1.sub.x-m H.sub.5-x)R.sup.2.sub.m (C.sub.5 R.sup.1.sub.y-m H.sub.5-y).sub.n MQ.sub.3-n (I) wherein M is a metal selected from the group consisting of Ti, Zr and Hf; C 5 R 1 x-m H 5-x and C 5 R 1 y-m H 5-y , which are the same or different from each other, are cyclopentadienyl rings; wherein the substituents R 1 are the same or different from each other, and are selected from the group consisting of Si(CH 3 ) 3 , alkyl, alkenyl, aryl, alkylaryl and arylalkyl radicals, said radicals having from 1 to 20 carbon atoms and optionally having Si or Ge atoms, or wherein one pair of R 1 substituents of the same cyclopentadienyl group forms a ring having from 4 to 6 carbon atoms and the other R 1 substituents are as defined above, or wherein two pairs of R 1 substituents of the same cyclopentadienyl group form two rings having from 4 to 6 carbon atoms; wherein R 2 is a bridging group which links the two cyclopentadienyl rings and is selected from the group consisting of CR 3 2 , C 2 R 3 4 , SiR 3 2 , Si 2 R 3 4 , GeR 3 2 , Ge 2 R 3 4 , R 3 2 SiCR 3 2 , NR 1 and PR 1 wherein the R 3 substituents, which are the same or different from each other, are selected from the group consisting of R 1 and hydrogen, or wherein one pair of the R 3 substituents forms a ring having from 3 to 6 carbon atoms, or two pairs of the R 3 substituents form two rings having from 3 to 6 carbon atoms; the Q substituents, which are the same or different from each other, are selected from the group consisting of hydrogen, halogen, OH, SH, R 1 , OR 1 , SR 1 , NR 1 2 and PR 1 2 ; m is 0 or 1; n is 0 or 1, n being 1 when m=1; x is an integer of from m+1 to 5; and y is an integer of from m to 5: (B) an organometallic aluminium compound of the formula (II): AlR.sup.4.sub.3-z H.sub.z (II) wherein the R 4 substituents, which are the same or different from each other, are selected from the group consisting of alkyl, alkenyl and alkylaryl radicals containing from 1 to 10 carbon atoms, said radicals optionally containing Si or Ge atoms, with the proviso that at least one of the R 4 substituents is different from a straight alkyl group; z is 0 or 1; and (C) water: the molar ratio of the organometallic aluminium compound to the water being from 1:1 to 100:1, with the proviso that contacting the organometallic aluminium compound with the water results in an aluminium reaction product in which at least a part of said aluminium reaction product is in a form different from an alumoxane compound of formula (III): ##STR2## wherein the R 4 substituents, which are the same or different from each other, are as defined above.