| 摘要 |
<p>1,131,588. Polymerizing vinyl chloride. PRODUITS CHIMIQUES PECHINEYSAINT-GOBAIN. 28 June, 1967 [28 June, 1966], No. 29793/67. Heading C3P. A two-stage bulk polymerization of vinyl chloride is effected in the first stage with a high degree of turbulence under hot conditions (20-75‹ C., 2-14 bars) with a catalyst of short half life and in the second in a separate autoclave polymerizer with low agitation under cold conditions (- 60‹ to +20‹ C., 65 mm. mercury-2 bars) in the presence of added catalyst and a C 1 -C 4 aliphatic alcohol and optionally a halogen-containing chain length regulator. The first stage may be applied to only part of the monomer. The first stage catalyst is sulphonyl cyclohexane acetyl peroxide, isopropyl peroxydicarbonate or ethylhexyl peroxydicarbonate, and in the second stage is used hydrogen peroxide, ferric sulphate and ascorbic acid or a peroxide with boron trialkyl-hydrazine complex and optionally oxygen. The alcohol is methanol, ethanol or isopropanol. The apparatus of Specifications 1,047,489 and 1,056,674 may be used.</p> |
