| abstract |
The invention relates to dispersions of crosslinked polymer microparticles in aqueous media, which are characterized in that they have been prepared by (1) dispersing a mixture of components (A) and (B) in an aqueous medium, the component ( A) one or more polyester polyol (s) containing at least 2 hydroxyl groups, and component (B) consists of one or more polyisocyanate compound (s), the isocyanate groups of which are at least partially in blocked form, and wherein components (A) and / or (B) has a sufficient number of ionic groups, preferably carboxylate groups, to form a stable dispersion and at least some of the components (A) and / or (B) contain more than 2 hydroxyl groups or optionally blocked isocyanate groups per molecule and ( 2) the dispersion thus obtained has subsequently been heated to such an extent that components (A) and (B) surround to form crosslinked polymer microparticles have been replaced. |