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    MANUFACTURE OF STYRENE POLYMERS WHICH HAVE BEEN MODIFIED TO IMPROVE THEIR IMPACT STRENGTH
    12.
    发明专利
    MANUFACTURE OF STYRENE POLYMERS WHICH HAVE BEEN MODIFIED TO IMPROVE THEIR IMPACT STRENGTH 未知

    公开(公告)号：CA1114984A

    公开(公告)日：1981-12-22

    申请号：CA273939

    申请日：1977-03-14

    Applicant: BASF AG

    Inventor： WALTER MANFRED ,  STEIN DIETER ,  FAHRBACH GERHARD ,  JUNG RUDOLF ,  ECHTE ADOLF

    IPC: C08F291/00 ,  C08F279/02 ,  C08F291/02 ,  C08F253/00

    Abstract: The invention is concerned with a process for the manufacture of a styrene polymer modified with rubber to improve its impact strength, by polymerizing styrene in the presence of 1 to 20% by weight, based on styrene, of rubber in at least two stages, wherein, in a first stage, the styrene, which contains the rubber in solution, is prepolymerized at from 50 to 150.degree.C in the presence or absence of inert diluents, while breaking up the disperse soft-component phase which forms during the polymerization by shearing the polymerization mixture until the quantity of styrene converted, based on the starting solution to be polymerized, corresponds to from 3 to 10 times the amount of elastomer constituent of the total amount of rubber employed and the particles of the disperse soft component phase thus formed have a mean diameter of less than 6 .mu.m, and thereafter, in one or more further stages, the polymerization is completed by taking it to the desired conversion with reduced shearing or entirely without shearing, in mass, in solution or in aqueous suspension. The process of the invention is characterized in that the shearing during prepolymerization is carried out in such a way that the particles have a weight-average mean diameter of less than 1 .mu.m and a narrow particle-size distribution, and the disperse soft-component phase contains, during the prepolymerization, from 35 to 65% by weight of free or chemically bonded polystyrene segments being incorporated into the rubber component in a chemically bonded form as a polymer block or a grafted branch, the segments having a number-average molecular weight of at least 30,000. The styrene polymers obtained exhibit not only high impact strength but also improved transparency, and may be used for packaging purposes.

    CATALYTIC POLYMERISATION OF PROPYLENE
    16.
    发明专利
    CATALYTIC POLYMERISATION OF PROPYLENE 未知

    公开(公告)号：AU535865B2

    公开(公告)日：1984-04-05

    申请号：AU6964781

    申请日：1981-04-16

    Applicant: BASF AG

    Inventor： JUZA DIRK ,  STEIN DIETER

    IPC: B01J8/08 ,  C08F2/34 ,  C08F4/64 ,  C08F10/06

    Abstract: A process for the preparation of propylene homopolymers or copolymers by polymerizing the monomer or monomers in the gas phase in a centric stirred bed of finely divided polymer, with removal of the heat of polymerization by evaporative cooling, the temperature in the polymerization zone being regulated by measuring the temperature continuously and causing any change therein to trigger a change in the amount of liquid monomer, evaporating in the reaction zone, which is introduced per unit time, in which process (1) the radius and height of the centric stirred bed are in a particular ratio to one another, (2) the finely divided polymer in the centric stirred bed is caused to move upward in the peripheral zone of the bed and downward in the central zone of the bed, (3) the temperature in the polymerization zone is regulated by simultaneously measuring it at (3.1) one or more points of the inner part of the stirred bed and (3.2) one or more points of the outer part of the stirred bed and (4) the actual temperatures T determined simultaneously at the individual points of measurement are combined to give a temperature parameter TM and the difference of this parameter from the intended value triggers the regulating sequence, or the temperature differences DELTA T between the actual and intended temperatures, measured simultaneously at the individual points of measurement, are combined to give a difference parameter DELTA TM and this parameter triggers the regulating operation.

    TRANSPARENT POLYMER MIXTURES HAVING HIGH IMPACT STRENGTH
    17.
    发明专利
    TRANSPARENT POLYMER MIXTURES HAVING HIGH IMPACT STRENGTH 未知

    公开(公告)号：CA1087340A

    公开(公告)日：1980-10-07

    申请号：CA272390

    申请日：1977-02-21

    Applicant: BASF AG

    Inventor： FAHRBACH GERHARD ,  GERBERDING KARL ,  MITTNACHT HANS ,  SEILER ERHARD ,  STEIN DIETER

    IPC: C08L25/06 ,  C08L53/02

    Abstract: Mixtures of polystyrene and a block copolymer of a monovinyl-aromatic compound and a conjugated diene. The mixture contains a thermoplastic, non-elastomeric block copolymer having a star-shaped branched structure, the branches being of at least two types of different average composition, and at least 50% by weight of the monovinyl-aromatic compound being present as terminal polymer blocks in one or more of the branches. The mixtures, which exhibit good transparency and high impact strength, are particularly suitable for the manufacture of moldings and packaging materials.

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