3.
    发明专利
    未知

    公开(公告)号:ES2101519T3

    公开(公告)日:1997-07-01

    申请号:ES94910369

    申请日:1994-03-05

    Applicant: BASF AG

    Abstract: PCT No. PCT/EP94/00662 Sec. 371 Date Aug. 2, 1995 Sec. 102(e) Date Aug. 2, 1995 PCT Filed Mar. 5, 1994 PCT Pub. No. WO94/21719 PCT Pub. Date Sep. 29, 1994A process for the preparation of bead-form expandable styrene polymers by polymerizing styrene, if desired in the presence of further comonomers, in aqueous suspension in the presence of organic molecular colloids as suspension stabilizers and conventional styrene-soluble polymerization catalysts and with addition of a blowing agent and, if desired, conventional additives in effective amounts, wherein the aqueous suspension contains at least one olefinically unsaturated carboxylic acid or a water-soluble salt thereof in an amount, based on the organic phase, of from 0.002 to 0.3% by weight of carboxylate anions.

    Preparation of expandable thermoplastic polymers by post-impregnation

    公开(公告)号:AU657626B2

    公开(公告)日:1995-03-16

    申请号:AU4133893

    申请日:1993-06-18

    Applicant: BASF AG

    Abstract: A process for the preparation of expandable thermoplastic polymers by post-impregnation with a blowing agent in liquid suspension in the presence of a mixture of magnesium pyrophosphate and a sulphonate group-containing extender as suspension stabiliser in a reactor, characterised in that a) the magnesium pyrophosphate is prepared in the same reactor at a temperature below 50 DEG C by addition of a solid magnesium salt in an amount corresponding to an at least 3% stoichiometric excess, based on pyrophosphate, to an aqueous solution of the pyrophosphate, b) the suspension medium is heated to a temperature in the range between 70 and 140 DEG C, and c) the blowing agent is added in this temperature range.

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