| 摘要 |
<p>1,207,767. Polymerizing vinyl chloride. SOLVAY ET CIE. 27 May, 1969 [7 June, 1968], No. 26658/69. Heading C3P. Vinyl chloride is polymerized or copolymerized in the presence of a dispersion of a particulate solid in a non-solvent liquid, preferably water, containing no dispersing agent and a free radical catalyst insoluble in the liquid, the monomers being introduced in gaseous form and the pressure being maintained below the saturated vapour pressure of the monomers. The solid may be asbestos, silica, perlite, a stabilizer or preferably a plastic, particularly porous PVC. In the examples, homopolymers and copolymers with propylene or isobutene are formed using PVC, optionally with calcium stearate as the solid and lauroyl peroxide or azobisisobutyronitrile as catalyst. Porous granules are obtained.</p> |
