| 摘要 |
A re-dispersible plastic powder is prepd. by drying an aq. plastic dispersion having min. film-forming temp. below 60-, pref. below 50- (below 40-) esp. below 35 deg.C, and contg. a dispersed copolymer having dynamic freezing temp., T (lambda-max.) below 150 deg.C, built up, by wt., of 20-60% acrylic- and/or methacrylic acid units, 40-80% lower acrylate and/or methacrylate units or their mixts. with styrene as well as opt. up to 10% units of further unsatd., radically polymerisable co-monomers. The novelty consists in drying the dispersion by spray-drying at an inlet temp. below the dynamic freezing temp. but above the min. film-forming temp. and at an outlet temp. below 65 deg.C but above the min. film-forming temp.
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