| 摘要 |
<p>Polyurethane elastomers having a Shore A-hardness, measured at 60.degree.C, of 80.degree. and having improved mechanical properties, particularly with respect to resistance to continued tearing at 100.degree.C, are obtained by reacting up to 20% by weight of a diisocyanate with a polyester diol having a molecular weight between 2000 and 20000, the polyester diol being formed by the reaction of a dicarboxylic acid, or a functional derivative thereof, selected from the group consisting of adipic acid, azelaic acid, sebacic acid, maleic acid, terephthalic acid, isophthalic acid and phthalic acid with an aliphatic diol selected from the group consisting of ethylene glycol, 1,4butanediol, diethylene glycol and 1-methyl ethylene glycol and a cyclic or heterocyclic diol selected from the group consisting of 4,4'-di-(2-hydroxyethoxy)-diphenylmethane, 1,4di-(2-hydroxyethoxy)-benzene, bis-¢5,5-dimethyl-3-(2-hydroxy-methyl)-hydantoinyl!-methane, bis-¢5,5-dimethyl-3-(2-hydroxy-ethyl)-hydantoinyl!-methane, bis-¢5,5-dimethyl-3-(2-hydroxypropyl)-hydantoinyl!-methane, bis-{1-methyl-2-¢1-(2-hydroxymethyl)-5,5-dimethyl-hydantoin-3-yl!}-ethyl sebacate, 1,3-di-(2-hydroxyethyl)-5,5-dimethyl hydantoin, 1,3-di-(2-hydroxypropyl)-5,5-dimethyl hydantoin, 1,3-di-(2-hydroxyethyl)-benzimidazolone, 1,3-di- (2-hydroxyethyl)-4,5,6,7-tetrabromobenzimldazolone, 1,3-di- (2-hydroxyethyl)-4,5,6,7-tetrahydrobenzimidazolone and 1,3di-(2-hydroxypropyl)-benzimidazolone.</p> |
