| 摘要 |
<p>1300030 Polysiloxane - polyoxyalkylene antifoam compositions for latexes DOW CORNING CORP 7 Oct 1971 [17 May 1971] 46712/71 Headings C3P C3R and C3T An antifoam composition, particularly effective in latexes, comprises (1) 5-50 wt. per cent of a polyoxyalkylene polysiloxane of the general formula wherein x has an average value 6-420, y has an average value 3-30, and G is a radical -D(OR) z A, where D is an alkylene radical, R is an ethylene, propylene or butylene radical, z has an average value 10-100, the C : O ratio in (OR) z is 2À3-2À8 : 1, and A is a terminal group, (2) 5-50 wt. per cent of polypropylene glycol of molecular weight 1000-2000, (3) 5-50 wt per cent of a glycol copolymer wherein a and b have average values such that the molecular weight is 2000-3000, D<SP>1</SP> is a C 1-16 alkylene radical, m is 0 or 1, and R<SP>1</SP> is a terminal group, and (4) 40-85 wt. per cent of water. In examples such a composition is added to styrene-butadiene and acrylonitrile-butadiene rubber latexes.</p> |
