A TRANSPARENT PUD AND ITS APPLICATION

The present invention relates an aqueous dispersion comprising at least one polyurethane, wherein the at least one polyurethane is prepared from at least the following components (A) at least one polyisocyanate, (B) at least one polymeric polyol having a number average molecular weight of 400 to 6000 g/mol, wherein at least one polycarbonate polyol is present in the polymeric polyol component (B) in an amount of 55 to 100% by weight, based on total weight of component (B), (C) optionally at least one monofunctional nonionic hydrophilizing agent, (D) at least one compound selected from the group consisting of polyols, aminopolyols, polyamines and mixtures thereof, in each case having a number average molecular weight of less than 400 g/mol, (E) at least one compound selected from the group consisting of monools, diols, polyols, monoamines, diamines, polyamines and mixtures thereof, in each case having at least one salt group, preferably an anionic group, or a functional group that can be converted into a salt group, preferably into a anionic group, (F) at least a neutralizer selected from the group consisting of tertiary amine compounds with boiling point above 100 °C at atmospheric pressure, inorganic alkali, preferably potassium hydroxide, sodium hydroxide, and mixtures thereof, wherein the at least one polyurethane dispersion has an average particle diameter D(i)90 in the range of 20 nm to 95 nm and wherein the viscosity of said dispersion is 50 to 1500 mPa·s, to a coating formulation comprising such an aqueous dispersion, to the use of this aqueous dispersion in a coating formulation, to the process for the coating of a substrate, wherein a coating formulation comprising such an aqueous dispersion used, to the use of such a coating formulation for coating of a substrate and to a substrate coated with the coating formulation. La présente invention concerne une dispersion aqueuse comprenant au moins un polyuréthane, ledit au moins un polyuréthane étant préparé à partir d'au moins les composants suivants : (A) au moins un polyisocyanate, (B) au moins un polyol polymère présentant une masse moléculaire moyenne en nombre de 400 à 6000 g/mol, au moins un polycarbonate polyol étant présent dans le composant polyol polymère (B) à hauteur de 55 à 100 % en poids, sur la base du poids total du composant (B), (C) éventuellement au moins un agent hydrophilisant non ionique monofonctionnel, (D) au moins un composé choisi dans le groupe constitué des polyols, des amin