| 摘要 |
<p>Vinyl chloride homo-, co- or graft copolymers are prepd. by polymerising vinyl chloride alone or with up to 30wt.%, w.r.t. vinyl chloride, of at least 1 copolymerisable monomer and/or of at least 1 polymer which is graft-copolymerisable with vinyl chloride. Polymerisation takes place in aq. suspension or bulk, at 30-80(40-65) deg.C, opt. with the addn. of dispersants and other additives. Novelty consists in using an oil-soluble catalyst system contg., by wt. w.r.t. monomers, (a) 0.001-0.5(0.01-0.1)% cumyl perneodecanoate (A), and (b) 0.001-0.5(0.01-0.1)% of at least 1 further standard peroxide gp.-contg. vinyl chloride polymerisation catalyst (B), having 1 hr. half-value temp. 50-100 deg.C. Deposit formation on reactor wells is reduced, thereby reducing faults, e.g. fish-eyes or flecking in thermoplastic working. Polymerisation batch running time, to achieve a given conversion, and max. heat removal, expressed as temp. difference between internal polymerisation reactor temp. and cooling jacket temp., are reduced.</p> |
