| 摘要 |
<p>Batch prodn. of a vinyl halide polymer latex is effected by (a) polymerising a monomer matl. contg. a vinyl halide in aq. microsuspension in the presence of a monomer-soluble free radical initiator, and (b) adding 40 (30) esp. 4-20 wt % of the monomer matl. based on the monomer matl. used in step (a), after the conversion of 40-80% of the monomer matl. used in step (a), the amt. of monomer matl. added and the rate of addn. being such that the stability of the latex is maintained, and the monomer matl. being added in the mass, without being dispersed or suspended in water. Gives stable latex with a high solids content without a proportional increase in the duration of polymn. The monomer matl. is pref. vinyl chloride, opt. mixed with =30 wt % comonomer.</p> |
