Aqueous polyurethane - vinyl polymer hybrid dispersions

Aqueous polyurethane-vinyl polymer hybrid dispersions comprising, as building blocks, hydrophobically modified hydroxy-functional polyesters A, acids B that have further groups which react with isocyanates under formation of urethanes, ureas, or thiourethanes, optionally, hydroxy-functional oligomeric or polymeric compounds C which may be polyesters, polycarbonates, polyethers, polyamides, polydienes and polyenes, and which have at least two hydroxyl groups per molecule, optionally, monomeric hydroxy compounds D having at least two hydroxyl groups per molecule, optionally, compounds E having at least one primary or secondary amino group, and at least one hydroxyl group per molecule, optionally, compounds F having two or more primary or secondary amino groups per molecule and no hydroxyl groups, compounds G having only one hydroxyl group, and one or more tertiary amino groups, olefinically unsaturated monomers H2 having a polymerisable ethylenic unsaturation and a further functional group which reacts with an isocyanate group under bond formation, olefinically unsaturated monomers H1 having at least one polymerisable ethylenic unsaturation and no further functional group which reacts with an isocyanate group, and multifunctional isocyanates I having at least two isocyanate groups per molecule, wherein the hydrophobically modified polyesters A are obtained from a polyester A′ having residual hydroxyl and acid groups, by reaction of the acid groups thereof with a mono-functional compound A4 having an epoxide or aziridine functionality, and a linear or branched alkyl residue of at least four carbon atoms, in which reaction at least 90% of the remaining acid groups of the polyester A′ are converted to ester or amide groups.