| abstract |
Base coating compositions for the production of protective and/or decorative multilayered coating composed of aqueous dispersions containing a) as film-forming material, at least a polyurethane resin with an acid number between 5 and 70, an intermediate product having at the end of the chains isocyanate groups being prepared with A) linear polyethers and/or polyester diols with a molecular weight between 400 et 3000; B) diisocyanates; C) complexes containing two groups which are reactive to isocyanate groups, at least a portion of these complexes, which form the component (C), containing at least one anion forming group, preferably neutralised before its conversion with a tertiary amine. The free isocyanate groups of the intermediate are then converted with a polyol which contains at least three hydroxy groups, preferably triol; b) pigments and c) other usual additives. |