| 摘要 |
<p>Chloroprene is (co)polymerised, opt. with up to 50 wt.% comonomers, in neutral, acid or alkaline aq. medium in the presence of known surface active agents, using an activator system consisting of (a) a mineral peroxy cpd., (b) an alkali salt of anthraquinone-2-sulphonic acid and (c) formamidine sulphinic acid (I). Pref. the total amt. of (a)+(b)(c) used in 0.02-0.6 wt.% on monomers and the activator compsn. contains 4.5-25 wt.% (a) 0.5-2.5 wt.% (b) and 95-50 wt.% (c) with a wt. ratio na):(b)=2:1 to 10:1. The alkali salt (b) suppresses the induction period of the mineral peroxy cpd., while the formamidine cpd. (c), which is pref. added continuously during the polymerisation, controls the decomposition of the peroxy cpd. to give uniform release of initiator throughout the polymerisation. This gives lower consumption of activator and allows polymerisation to be carried out at lower temps. than with prior art catalyst systems. The resulting polymers are uniform and have a reduced gel content, while the formation of deposits on the reactor walls is eliminated. The stable viscosity polymer lateices produced are useful e.g. in the prodn. of adhesives.</p> |
