Low-viscosity polyurethane acrylate dispersions

摘要

The present invention relates to a process for the preparation of low-viscosity, radiation-curable, aqueous dispersions based on polyurethane acrylates (UV-PUDs), wherein the UV-PUDs hydrophilized via hydroxy-functionalized carboxylic acids have a lower initial viscosity when a large part of the urethanization, that is to say the reaction of the NCO-functionalized compounds with the OH-functionalized compounds, initially takes place in the absence of the acid-carrying compounds and the incorporation of the acid-carrying compounds via their hydroxyl function takes place as late as possible.