Process for the preparation of aqueous polyurethane dispersions and solutions

摘要: The present invention relates to a process for the preparation of aqueous solutions or dispersions polyurethanes, in which prepolymers have at least two free isocyanate groups and contain chemically-fixed hydrophilic and/or external emulsifiers are not chemically fixed reacted with chain lengthening agents phase, characterized that prepolymer is hydrophilically modified contains an emulsifier mixed selected from group consisting azines hydrazones absence water mixture obtained then water. also can be by this process. Lastly, use coating flexible substrates.