25.
    发明专利
    未知

    公开(公告)号:DE3784148D1

    公开(公告)日:1993-03-25

    申请号:DE3784148

    申请日:1987-11-25

    Applicant: BASF AG

    Abstract: Continuous prodn. of random copolymers (I) of propene with other monoalkenes is carried out in the qas phase in the presence of a Ziegler-Natta catalyst system at 50-80 deg.C and 20-35 bar in a centric stirred bed of small polymer particles with a Froude No. of 1-3, in which the heat of polymerisation is removed by evaporative cooling. The monomer mixt. is supplied and (I) is discharged from the polymerisation zone continuously or cyclically. The process is carried out under conditions such that: (a) the polymerisation zone is kept in a pressure and temp. range at which the monomer mixt. is gaseous; (b) the unpolymerised monomer mixt. is discharged as gas, liquefied, stored and recycled to the polymerisation zone in liq. form; (c) the temp. in the polymerisa-tion zone is controlled by monitoring the temp. continuously and varying the amt. of liq. monomer mixt. introduced in unit time, which vaporises in the reactor; and (d) replacing the polymerised monomers by supplying fresh monomers. The novelty is that the monomer mixt. used contains 0.5-3.5 mole-% ethylene and 0.2-1.0 mole-%. H2 w.r.t. propene nand the dwell time of the monomer mixt. in the polymerisation zone is 0.5-8 min.

    Use of a special propene polymer in the production of heat-sealable films

    公开(公告)号:DE3732933A1

    公开(公告)日:1989-04-13

    申请号:DE3732933

    申请日:1987-09-30

    Applicant: BASF AG

    Abstract: The framework of the invention is the production of heat-sealable films consisting of (i) a basic film of polypropene (polypropylene) and (ii) a heat-sealable layer which is applied to the basic film and comprises a propene polymer with a relatively low softening point. The characteristic feature is that the propene polymers used for the heat-sealable layer are those obtained by continuous production of random copolymers of propene by polymerisation of a monomer mixture by means of a Ziegler-Natta catalyst system in the gas phase in a centric stirred bed comprising small-particulate polymer with removal of the heat of polymerisation by evaporative cooling, the monomer mixture being introduced constantly into the polymerisation zone and the polymer being constantly discharged from the polymerisation zone, with the provisos that (a) in the polymerisation zone pressure and temperature are kept in a range corresponding to the gaseous state of the monomer mixture, (b) gaseous, unconsumed monomer mixture is discharged from the polymerisation zone and reintroduced into the polymerisation zone in the liquid state, (c) the temperature in the polymerisation zone is controlled by means of the amount of liquid monomer mixture introduced per unit time, and (d) the monomer consumed by polymerisation is replaced, with the special feature that - with the use of a monomer mixture comprising principally propene, a little ethene and very little hydrogen - the residence time of the ... Original abstract incomplete.

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