| 摘要 |
<p>Aq. catalyst compsns. are comprised of dispersions of (a) 1-40 wt.% of an oil sol. catalyst which is stable on storage at >-5 degrees C, chosen from (1) diacetyl- or diaryl peroxides, and/or (2) peroxidicarbonates, and/or (3) organic azo cpds. (4) mixed anhydrides of organic sulphonic acids with organic acids and/or (5) organic peresters; (b) 0.01-5 wt.% natural or synthetic protective colloids and/or (c) 0.5-20 wt.% anionic, cationic or non-inonic emulsifiers, with a dispersion particle sie of 300 mu m, pref. 1-100 mu m. The catalyst dispersions are stable and do not sediment out on storage, while the catalyst retains its activity over long periods. The catalyst are useful in dispersion polymerisation operations, as a replacement for the solns. of catalysts in organic solvents normally used. The latter produce solvent residues in the polymer, a disadvantage e.g. for packaging applications, and catalyst activity tends to fall during storage. The aq. catalyst dispersion are pumpable and easily metered, and are esp. useful for micro pearl polymerisation processes.</p> |
