COATING MEDIUM, THE USE THEREOF, AND A PROCESS FOR MULTILAYER COATING

摘要

A coating medium suitable for multilayer coatings, containing A) copolymers containing hydroxyl groups, comprising a1) 8 - 12 % by weight of vinyl esters of alpha,alpha,dialkyl-substituted, branched, aliphatic saturated monocarboxylic acids, a2) 32 - 42 % by weight of hydroxyalkyl esters of (meth)acrylic acid, a3) 25 - 40 % by weight of alkyl esters of (meth)acrylic acid, a4) 12 - 24 % by weight of cycloalkyl esters of (meth)acrylic acid, and a5) 2 - 4 % by weight of (meth)acrylic acid with a hydroxyl number of 100 - 160 mg KOH/g, an acid number of 10 - 50 mg KOH/g, a number average molecular weight (Mn) of 1000 to 3000 g/mole and a glass transition temperature (Tg) of 30 - 80.degree.C, B) polyisocyanates in a quantitative proportion such that 0.5 to 2 isocyanate groups are allotted to one hydroxyl group of component A), and C) solvents and optionally one or more pigments, extenders and/or customary lacquer additives.