Vinyl pyrrolidone copolymer as protective colloid - in suspension polymn of styrene - to facilitate working in easily cla

摘要

Clarifiability of the aq. serum formed in polymn. of styrene in aq. suspension and in presence of a protective colloid based in vinyl pyrrolidone polymer is improved by using, as protective colloid, 0.1 - 0.5% w.r.t. wt. of monomer, a copolymer of 50 - 95 wt. % vinyl pyrrolidone units and 50 - 5% units of an alkali- or ammonium-salt of (meth)acrylic acid.