COATING AGENTS AND USE THEREOF AS PRIMERS AND/OR FILLERS IN THE PRODUCTION OF MULTILAYER COATINGS

摘要

: The description relates to coating agents for use as primers and fillers in the manufacture of multilayer lacquer coatings, more particularly in the motor-vehicle sector. The coating agent contains a binder mixture of A) 60 - 75 wt.% of a hydroxy-functional copolymer with an OH number of 110 to 170 mg KOH/g, obtainable from a) 5 - 60 wt.%, preferably 10 - 30 wt.% of at least one diester of an alpha, beta-olefinically unsaturated dicarboxylic acid with saturated monohydric alcohols containing 1 - 8 carbon atoms, b) 10 - 70 wt.%, preferably 35 - 60 wt.%, of one or more vinyl aromatic hydrocarbons, c) 0 - 30 wt.%, preferably 0 - 15 wt.% of one or more glycidyl esters of aliphatic saturated monocarboxylic acids branched in the alpha position, d) 25 - 50 wt.% of at least one hydroxy alkyl ester or a mixture of at least one alkyl ester and one hydroxyl alkyl ester of an alpha, beta-olefinically unsaturated monocarboxylic acid, and e) 0 - 10 wt.% of one or more alpha, beta-unsaturated monocarboxylic acids, B) 1 - 6 wt.% of ester-soluble nitrocellulose, C) 0.5 - 1.8 wt.% calcium oxide and D) 25 - 35 wt.% of one or more divalent or polyvalent polyisocyanates.