PREPARATION OF A MULTICOAT COATING,WATER-THINNABLE COATING COMPOSITIONS,WATER-THINNABLE EMULSION POLYMERS AND PREPARATION OF WATER-THINNABLE EMULSION POLYMERS

摘要

a process for the preparation of multicoat coatings in which a pigmented aqueous basecoat composition is used which comprises a water-thinnable emulsion polymer as the film-former. The water-thinnable emulsion polymer is prepared in a two-stage emulsion polymerization. The first stage gives rise to a polymer having a glass transition temperature (T G1) of +30 to +110.degree.C. In the second stage a mixture of monomers is polymerized in the presence of the polymer prepared in the first stage which by an exclusive polymerization gives rise to a polymer having a glass transition temperature (T G2) of -60 to +20.degree.C. The hydroxyl value of the emulsion polymer is between 2 and 100.