Highly active Ziegler type catalyst for ethylene (co)polymerisation

摘要

Ethylene opt. with other alpha-olefin in (co)polymerised in the presence of a catalyst system obtd. by bringing together in contact with one another (A) a reaction prod. (i) obtd. by reacting an intermediate reaction prod. (ii) obtd. by reaction of a hydropolysiloxane (I) with a Grignard reagent (II), with at least 1 nucleophilic reagent (III) chosen from an aldehyde, a ketone and an alcohol; (B) a transition metal cpd., and (C) at least 1 organoaluminium cpd. - High catalytic activity is obtd. even at a high temp. of at least 170 deg.C. Since the catalyst residue in polymer is minimised, the removal step may be omitted. Since the washing of the solid catalyst component prior to supplying it to the reactor is not required, the prepn. of the catalyst is simplified. EPAB- EP-101747 B A process for producing polyethylene which comprises polymerising ethylene ro copolymerizing ethylene with other alpha-olefin in the presence of a catalyst system obtained by bringing the following components (I) to (III) in contact with one another: (I) a reaction product (B) obtained by reacting an intermediate reaction product (A) obtained by a reaction of a hydropolysiloxane with a Grignard reagent, with at least one nucleophilic reagent selected from an aldehyde, a ketone and an alcohol, (II) a transition metal compound, and (III) at least one organic aluminium compound. USAB- US4657996 A Prodn. of polyethylene by: (co)polymerising ethylene in the presence of a catalyst system obtd. by bringing into contact (I) a reaction prod. obtd. by reacting an intermediate reaction prod. obtd. by reaction of a hydropolysiloxane with a Grignard reagent which is synthesised in the presence of an ether cpd. with at least one nucleophilic reagent, (II) a transition metal cpd., and (III) organo-Al cpd(s). - Pref. the Grignard reagent is MgR2 or MgRX; R is 1-12C hydrocarbon gp., X is halogen; and the molar ratio of MgR:Si is 1:1-5. - Pref. (II) is mixt. of Ti and V cpds; and (III) is of formula AlR1m(OR2)SX(3-m-S)i R1 and R2 are 1-12C hydrocarbon gps., X is halogen, and m, s and m+s are 0-3. - The (co)polymerisation is carried out at 30-300 deg. C.