| 摘要 |
Particulate expandable styrene polymers having short minimum molding times which are coated with from 0.005 to 0.5% by weight, based on the expandable styrene polymer, of a mono- and/or poly-urethane melting below 150 DEG C. and obtained by reaction of I (a) aliphatic, cycloaliphatic, aliphatic-cycloaliphatic, araliphatic and aromatic mono- and/or poly-isocyanates with (b) linear or branched monoalcohols of from 2 to 24 carbon atoms which may or may not be olefinically unsaturated and/or halogenated, or mixtures of such monoalcohols and (c) optionally dihydric to tetrahydric alcohols, the ratio of NCO groups to the total number of hydroxyl groups being from 0.25 to approximately 1:1 and the molar ratio of dihydric to tetrahydric alcohols (if used) to polyisocyanates being not more than 0.4:1; or reaction of II (a) linear or branched aliphatic, cycloaliphatic, aliphatic-cycloaliphatic, araliphatic or aromatic chlorocarboxylates of from 2 to 24 carbon atoms in the alcohol radical, which may or may not be olefinically unsaturated and/or halogenated, with (b) aliphatic, cycloaliphatic, aliphatic-cycloaliphatic, araliphatic and aromatic mono- and/or poly-amines, the ratio of amino groups in the mono- and/or poly-amines to chlorocarboxylates being from 2:1 to 1:1. |
