| 摘要 |
Vinyl chloride homo, graft or co polymers comprising at least 80 % by weight of polymerised vinyl chloride are produced by polymerising the monomer(s) in aqueous emulsion or suspension in the presence or absence of polymers. The bulk of unconverted monomer is removed and then the aqueous dispersion of the polymer is subjected to a pressure of from 150 to 650 torr for at least 15 minutes to evaporate off from 0.2 to 20 kg of water per 100 kg of dispersion. This process achieves residual monomer contents of less than 0.005% by weight of vinyl chloride. This reduces any harmful physiological effect of monomeric vinyl chloride in the handling of these polymers. |
