| 摘要 |
<p>The present invention relates to aqueous polyurethane dispersions that are free from N-methylpyrrolidone and other solvents and wherein the polyurethanes ar e the reaction products of A) a mixture of 25% to 90% by weight of 1-isocyanate-3,3,5,-trimethyl-5 - isocyanatomethylcyclohexane (IPDI) and 10% to 75% by weight of 4,4'- diisocyanatodicyclohexylmethane, wherein the preceding percentages are based on the weight of component A), with B) one or more polyols having average molarcular weights (Mn) of 500 to 6000, C) one or more compounds which have at least one OH- or NH-functional group and contain a carboxyl and/or carboxylate group, wherein at least 50 mol% of the acid groups, based on the total moles of acid incorporated into the polyurethane, are incorporated by dimethylolpropionic acid, D) one or more polyols and/or polyamines having average molecular weigh ts (Mn) of below 500, and E) optionally one or more monoalcohols and/or monoamines. The present invention also relates to a process for preparing the aqueous polyure- thane dispersions and to the use of the polyurethane dispersions for prepari ng coatings or adhesives.</p> |
