ZIEGLER-NATTA-TYPE CATALYST SYSTEMS

    公开(公告)号:ZA908839B

    公开(公告)日:1992-07-29

    申请号:ZA908839

    申请日:1990-11-05

    Applicant: BASF AG

    Abstract: Catalyst systems of the Ziegler-Natta catalyst type, containing, as active constituents, a) a titanium-containing solid component which contains titanium, magnesium, halogen and a carboxylic acid ester, and, as cocatalyst, b) an aluminium compound and c) optionally further electron-donor compounds, characterised in that they contain in the solid component, as the carboxylic acid ester, a diester of a carboxylic acid of the formula Ia or Ib in which R , R , R and R are identical or different and are hydrogen, C1-C15-alkyl, C7-C15-alkylaryl or 5- to 7-membered cycloalkyl, which may itself carry C1- to C10-alkyl groups. These catalyst systems are particularly suitable for the preparation of polypropylene and copolymers of propylene with minor amounts of other alpha , beta -unsaturated olefinic compounds having 2 to 12 carbon atoms.

    PREPARATION OF PROPYLENE-ETHYLENE COPOLYMERS

    公开(公告)号:ZA90967B

    公开(公告)日:1991-10-30

    申请号:ZA90967

    申请日:1990-02-09

    Applicant: BASF AG

    Abstract: A process for the preparation of propylene-ethylene copolymers in an agitated fixed bed in which propylene is polymerised from the gas phase, initially in a first polymerisation zone at a pressure of from 20 to 40 bar and at a temperature of from 60 to 90 DEG C with feed of a Ziegler-Natta catalyst system, and, in a second polymerisation zone, at a pressure of from 7 to 35 bar and a temperature of from 40 to 70 DEG C, a mixture of olefins is polymerised onto the finely divided polymer discharged from the first polymerisation zone, is characterised in that, in the second polymerisation zone, a mixture of propylene, ethylene and a further alpha -olefin having 4 to 10 carbon atoms is polymerised on at a ratio between the partial pressures of propylene and ethylene in the range of from 100 : 20 to 100 : 120 and at a ratio between the partial pressures of propylene and the alpha -olefin in the range from 100 : 1 to 100 : 20, the pressure in the second polymerisation zone is chosen to be at least 5 bar below the pressure in the first polymerisation zone, and the weight ratio between the monomers reacted in the first and second polymerisation zones is such that it is in a range between 100 : 10 and 100 : 50.

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