| 摘要 |
<p>Oil-modified polyurethanes are prepared by reacting (a) a mixture of hydroxyl group-containing esters produced from a polyol and an unsaturated fatty acid or ester thereof with (b) a polyisocyanate containing one or more aromatic nuclei substituted by at least two chlorine atoms in each aromatic nucleus. Polyisocyanates specified are: 1-methyl-3,5, 6-trichlorophenylene-2,4-diisocyanate; 1-methyl-3,4,5 - trichlorophenylene - 2,6 - diisocyanate; 1 - methyl - 3,5 - dichlorophenylene - 2,4 - diisocyanate; 2,4,5,6 - tetrachlorophenylene - 1,3-diisocyanate; 2,4,6 - trichlorophenylene-1,3-diisocyanate; 2,3,5,6 - tetrachlorophenylene-1,4-diisocyanate or diphenylmethane 4,41-diisocyanate or naphthylene-1,5-diisocyanate chlorinated in the nucleus. The hydroxyl group containing polyester may be obtained by the reesterification of oils with polyols, e.g. linseed, dehydrogenated castor, soya, safflower, wood, oiticica or fist oils with glycerol, trimethylolpropane, trimethylolethane or pentaerythritol or diols, e.g. ethylene glycol. Also fatty acids, e.g. linoleic, linolenic, oleic, licanic or oleostearic esterified with polyols may be used. The polyurethanes may be used to prepare lacquers.</p> |
