Coating masses and their use as a primer and/or a putty for the preparation of multilayer coatings

摘要

The invention relates to coating compositions which are suitable for use as primers and fillers in the production of multicoat finishes, in particular in the automotive sector. The coating compositions contain a binder mixture comprising A) 60 - 75% by weight of a hydroxy-functional copolymer having an OH number of from 110 to 170 mg KOH/g, obtainable from a) 5 - 60% by weight, preferably 10 - 30 % by weight, of at least one diester of an alpha, beta-olefinically unsaturated dicarboxylic acid with saturated monohydric alcohols having 1 - 8 carbon atoms, b) 10 - 70% by weight, preferably 35 - 60% by weight, of one or more vinyl aromatic hydrocarbons, c) 0 - 30% by weight, preferably 0 - 15% by weight, of one or more glycidyl esters of alpha-branched aliphatic saturated monocarboxylic acids, d) 25 - 50% by weight of at least one hydroxyalkyl ester or a mixture of at least one alkyl ester and at least one hydroxyalkyl ester of an alpha,beta-olefinically unsaturated monocarboxylic acid, and e) 0 - 10% by weight of one or more alpha,beta-unsaturated monocarboxylic acids, B) 1 - 6% by weight of ester-soluble nitrocellulose, C) 0.5 - 1.8% by weight of calcium oxide and D) 25 - 35% by weight of one or more difunctional and polyfunctional polyisocyanates.