NO128823B

• Main Authors: FOURNEL F,FR, THOMAS J,FR, SOUSSEN S,FR
• Format: Patent
• Language: English
• Published: 14.01.1974
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOSITIONS BASED THEREON; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRINTED CIRCUITS; THEIR PREPARATION OR CHEMICAL WORKING-UP; THEIR RELEVANT APPARATUS; TRANSPORTING

1,215,741. Polymerizing vinyl chloride. PRODUITS CHIMIQUES PECHINEYSAINT-GOBAIN. 12 March, 1968 [14 March, 1967 (2)], No. 12017/68. Heading C3P. In the bwo-stage bulk polymerization or copolymerization of vinyl chloride, part of the monomer is allowed to evaporate, and the vapours are condensed and returned to the reaction; the first stage is effected with high turbulence to 7-15% conversion and the second stage with slow agitation. The two stages are effected in the same or separate reactors; reflux is effected at least in the second stage and preferably in both. All the monomer may be present in the first stage or only part, the remainder being added before the second stage. The reflux rate may be 0À3-3% per minute at the beginning reducing to 0À05- 0À1% as conversion reaches 75-90%. In one example vinyl chloride is copolymerized with vinyl acetate, in others it is homopolymerized. High density polymers having narrow partial size distribution are obtained.