Hydroxy-functional polyether-based reaction products and aqueous base paint which contains the reaction products

A pigmented aqueous basecoat material comprising a hydroxy-functional polyether-based reaction product that is preparable by urethane group-forming reaction of:

• (a) at least one component containing isocyanate groups that is preparable by urethane group-forming reaction of at least one organic diisocyanate (a1) with at least one polyether (a2) of the general structural formula (I),
• wherein R is a C3 to C6 alkylene radical, and n is selected accordingly such that the polyether (a2) possesses a number-average molecular weight of 500 to 5000 g/mol, wherein the components (a1) and (a2) are used in a molar ratio of 1.8/1.7 to 3.0/1.0, and a resulting component (a) has an isocyanate content of 0.5 to 10%, with
• (b) at least one organic polyol, wherein the amounts of components (a) and (b) are harmonized with one another such that the ratio of the molar amount of isocyanate groups in component (a) to the molar amount of component (b) is in a range from 0.33 to 0.95, and the resulting reaction product has a number-average molecular weight of 700 to 20,000 g/mol.