METHOD FOR PREPARING COATINGS IN MULTIPLE LAYERS ON ELECTRICALLY NON-CONDUCTIVE SUBSTRATES

摘要

A process for the production of multilayer coatings which give good optical properties, a good hardness/elasticity ratio and weathering resistance, in which an aqueous base coat containing up to 15 % by weight of organic solvents and an aqueous dispersion of A) from 70 to 100 % by weight of a cationic poly(meth)acrylate, polyester, polyurethane and/or polyurethane-urea resin which has been fully or partially neutralised by acids, having a number average molar weight (Mn) of from 500 to 500,000, and a OH number of from 0 to 450, an amine number of from 20 to 200 and a glass transition temperature of from -50 to +150 DEG C, and B) from 0 to 30 % by weight of an amine-formaldehyde condensation resin and/or of a blocked polyisocyanate, in each case containing at least two groups per molecule which are reactive towards the amino and/or OH groups and/or urethane and/or urea groups of component A) is applied to an electrically non-conducting surface of a substrate, a clear coat based on solvent-containing and/or water-containing, non-pigmented resins or a clear coat powder is then applied, and the base coat and clear coat are cured either separately or together at temperatures of below 160 DEG C.