Polyurethane modified alkyde resin dispersions

摘要

Aqueous polyurethane-alkyd resin dispersion (I) comprises reaction products of (a) at least an alkyd resin, in which at least 40 wt.% of fatty acids, capable for oxidative cross-linking with atmospheric oxygen is incorporated; (b) at least a bifunctional polyisocyanate; (c) at least a carboxyl/carboxylate functional and hydroxyl or amino functional hydrophilizing agents; (d) optionally diol and/or triol with a molecular weight of 62-600; (e) at least a diamine, optionally in combination with a triamine and/or amino alcohol and (f) optionally another components different from (a)-(e). Independent claims are included for: (1) the preparation of (I) comprising reacting (a)-(d) and optionally (f) in one or more reaction step to obtain isocyanate functional alkyd resin, where a solvent is added before, during or after the reaction, and the neutralization agent is added during or after the reaction, subsequently carrying out a first chain extension with a part of component (e) in an organic solution and then carrying out a second chain extension with the remaining of component (e) during or after the dispersion step, where the quantity ratio of the used component (e) to first and second chain extension step is 0.3-1 to 6-1; and (2) a binding agent combination comprising (I) and cross-linking resin based on polyisocyanate and/or amino cross-linking resin.