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    2.
    发明专利
    未知

    公开(公告)号：AT140932T

    公开(公告)日：1996-08-15

    申请号：AT92116233

    申请日：1992-09-23

    Applicant: BASF AG

    Inventor： FUNK GUIDO DR ,  HEMMERICH RAINER DR ,  GROPPER HANS DR ,  KOLK ERICH DR ,  FOLLMER GODOFREDO DR

    IPC: C08F4/02 ,  C08F4/06 ,  C08F4/22 ,  C08F4/24 ,  C08F4/69 ,  C08F10/00 ,  C08F10/02

    Abstract: In a new process for the preparation of a supported catalyst for the polymerisation of alpha -olefins, first a support gel (1) is prepared by introducing a sodium water glass or potassium water glass solution into a swirling stream of an aqueous mineral acid optionally containing aluminium ions longitudinally and tangentially to the stream, spraying the resultant silicic acid hydrosol in drop form into a gaseous medium, and allowing it to solidify to form a hydrogel, and freeing the resultant hydrogel, without prior ageing, from salts by washing and optionally from some of the water by extraction with alcohols and/or ketones, and then drying the hydrogel. This gives the support gel (1), which is ground and fractionated according to particle size. In a second process step, the support gel (1) is charged with chromium trioxide or with a chromium compound which can be converted into chromium trioxide, after which the resultant chromium-containing support gel (2) is heated at from 400 to 1100 DEG C for from 10 to 1000 minutes in an anhydrous gas stream containing oxygen in a concentration greater than 10% by volume. It is essential for the process according to the invention that the drying of the hydrogel to form the support gel (1) takes place in a high-speed drier within a maximum time of 300 seconds at an inlet temperature of from 200 to 600 DEG C. The supported catalyst prepared in this way gives homopolymers and copolymers of ethylene having excellent low-temperature toughness.

    Process for the preparation of polymers of ethylene
    6.
    发明专利
    Process for the preparation of polymers of ethylene 未知

    公开(公告)号：DE3244271A1

    公开(公告)日：1984-05-30

    申请号：DE3244271

    申请日：1982-11-30

    Applicant: BASF AG

    Inventor： GROPPER HANS DR ,  BRANDSTETTER FRANZ DR ,  WERNER MICHAEL DR

    IPC: C08F295/00 ,  C08F10/02

    Abstract: The invention relates to a process for the preparation of ethylene polymers from the monomers by carrying out the polymerisation first in a stirred autoclave reactor and subsequently in a tubular reactor, the polymerisation in the first reaction zone being carried out in the presence of transition-metal polymerisation catalysts and the polymerisation in the second polymerisation zone being carried out in the presence of polymerisation initiators which decompose to form free radicals, and the pressure in the second zone being kept lower than in the first.

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