| 摘要 |
A process is disclosed for producing aqueous polyurethane dispersions by reacting (a) dihydroxyl compounds having a molecular weight between 500 and 5000, (b) diisocyanates and if necessary (c) chain extenders with at least two hydrogen atoms capable of reacting with the isocyanate groups and a molecular weight lower than 300 in the melt or in the presence of an inert organic solvant (L) that can be mixed with water and that boils under 100 DEG C. A prepolymer with terminal isocyanate groups is thus obtained, then reacted with (d) salts of aliphatic aminocarbonic or aminosulfonic acids or tertiary ammonium salts, and dispersed in water. Before the polyurethane thus obtained is dispersed in water, 5 to 60 parts in weight, referred to 100 parts in weight of polyurethane, of a polymer (p), except condensates of phenol with formaldehyde and of epichlorhydrine with bisphenol A, dissolved in a solvant (L') that boils under 100 DEG C, are added to the polyurethane. The use of these compounds as adhesives and coating materials is also disclosed. |
