PROCESS FOR APPLYING A PRIMARY COAT OR A SINGLE LAYER OF LACQUER ON PLASTIC MATERIALS WITH AN AQUEOUS COATING AGENT

摘要

A process is disclosed for applying a primary coat or a single layer of lacquer on plastic materials with an aqueous coating agent which contains as film-building material one or several emulsion polymers, as well as a water-dilutable polyurethane resin. The process is characterised in that the aqueous coating agent contains an emulsion polymer. The emulsion polymer is prepared in a two-step emulsion polymerization from ethylenically unsaturated monomers. The conditions in which the reaction takes place are selected so that the thus obtained emulsion polymer has an average molar mass between 200,000 and 2,000,000 and a hydroxyl number from 2 to 100 and the absolute difference between the glass transition temperature (Tg1) of the polymer obtained during the first step and the glass transition temperature (Tg2) of the polymer which would be obtained if only the monomer used during the first step or only the mixture of ethylenically unsaturated monomers used during the second step was polymerized is comprised between 10 and 170 DEG C.