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    17.
    发明专利
    未知

    公开(公告)号：FI63245B

    公开(公告)日：1983-01-31

    申请号：FI771953

    申请日：1977-06-22

    Applicant: HOECHST AG

    Inventor： LEDERER MICHAEL ,  BOUMAN ANTONIUS J M

    IPC: C08F2/00 ,  C08F2/18 ,  C08F2/20 ,  C08F2/44 ,  C08F12/00 ,  C08F285/00 ,  C08F291/02 ,  C08F279/02 ,  C08F112/08

    Abstract: There is described an improved process for the discontinuous suspension polymerization of alkenyl-aromatic compounds, which comprises re-using the aqueous polymerization medium, after separation of the polymer beads, as the polymerization medium of a subsequent polymerization. Monomer-soluble and water-soluble initiators and, optionally fresh water and dispersing agent, are added. Re-using the aqueous polymerization medium does not negatively affect the color and mechanical properties of the polymer obtained. The process of the invention results in considerable saving of energy.

    PROCESS FOR THE PREPARATION OF FOAMABLE STYRENE POLYMERS
    19.
    发明专利
    PROCESS FOR THE PREPARATION OF FOAMABLE STYRENE POLYMERS 未知

    公开(公告)号：CA977100A

    公开(公告)日：1975-10-28

    申请号：CA127606

    申请日：1971-11-15

    Applicant: HOECHST AG

    Inventor： JASTROW HORST ,  LEDERER MICHAEL ,  HEISKEL ELMAR

    IPC: C08F271/00 ,  C08F283/12 ,  C08J9/20

    Abstract: 1334150 Preparation of foamable styrene polymer beads by suspension polymerization FARBWERKE HOECHST AG 15 Nov 1971 [16 Nov 1970] 52950/71 Headings C3P and C3C In a process for the production of foamable styrene polymer beads by suspension polymerizing styrene with or without up to 10% by weight of an alkyl styrene or nuclear halogenated styrene or up to 10% by weight of an acrylic or methacrylic acid ester, acrylonitrile, vinyl chloride, a vinyl ester or a vinyl polysiloxane, in the presence of a blowing agent, the protective colloid for the suspension is 0À02-0À08% by wt. based on the total monomer, of a copolymer of 98-99À5% by wt. of an N-vinyl-N- alkyl acetamide in which the alkyl is C 1-4 , and from 2-0À5% by wt. of a C 6-18 aliphaticalcohol ester of acrylic, methacrylic, maleic, or fumaric acid, said copolymer having a Fickentscher K value of 70-120, measured as a 1% methanol solution at 20‹ C. The preferred protective colloid is a copolymer of N-vinyl-N- methyl acetamide and 2-ethylhexyl acrylate. Other suitable comonomers for the N-vinyl-N- alkylacetamide are n-hexyl acrylate, decyl methacrylate, dodecyl maleate and stearyl fumarate. Blowing agents specified are npentane, isopentane, cyclopentane, hexane, petroleum ether, and halogenated hydrocarbons such as CFCl 3 , CF 2 Cl 2 , CH 3 Cl, and CH 2 Cl 2 . Nucleating agents for pore regulation may also be present, such as hexabromocyclododecane, tetrabromobutane, tris(dibromopropylphosphate), brominated butadiene oligomers and chlorine compounds such as chloro-paraffins and P.V.C., and polysiloxanes. The initiators used are conventional. Other additives such as flame retarders, plasticizers &c. may also be present. The blowing agent may be added before or during polymerization.

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