| 摘要 |
<p>1,245,977. Continuous alfin polymer formation and purification. NATIONAL DISTILLERS & CHEMICAL CORP. 3 Oct., 1968 [4 Oct., 1967], No. 46949/68. Heading C3P. Polymers are obtained by continuously blending alfin catalyst, monomer, solvent (or diluent) and molecular weight moderator, continuously polymerizing, continuously separating volatile materials (i) by flashing at a reduced pressure and elevated temperature at the end of polymerization and in the absence of water and of a catalyst deactivator, and. (ii) quenching the reaction mixture in water, and steam distilling the resulting dispersion, and thereafter recovering monomer and solvent and recycling them, and washing and drying the alfin polymer. The flashing step prior to watertreatment enables solvent free of acetylene and cyclopentadiene impurities to be obtained, since the latter are liberated from their sodium salts on contact with water. Suitable monomers are conjugated dienes and alkenyl aromatic compounds, the polymerization of butadiene and of isoprene, and the copolymerization of butadiene with styrene or with isoprene (exemplified) being particularly mentioned. Two detailed flow diagrams (not shown) are provided.</p> |
