| 摘要 |
The invention relates to nonaqueous coatings containing a polyacrylate resin and a urea group-containing thixotropic agent and having improved surface properties. The polyacrylate resin is prepared by polymerizing (a) from 16 to 51% by weight of a hydroxyl group-containing ester of acrylic acid or methacrylic acid or of a mixture of such monomers; (b)from 32 to 84% by weight of an aliphatic or cycloaliphatic ester of acrylic acid or methacrylic acid which is different from (a) and has at least 4 carbon atoms in the alcohol radical or of a mixture of such monomers; (c) from 0 to 2% by weight of an ethylenically unsaturated carboxylic acid or of a mixture of ethylenically unsaturated carboxylic acids, and (d)from 0 to 30% by weight of an ethylenically unsaturated monomer which is different from (a), (b) and (c) or of a mixture of such monomers. The polyacrylate resin has an acid number of from 0 to 15, a hydroxyl number of from 80 to 140, and a number-average molecular weight of from 1,500 to 10,000, the sum of the proportions by weight of components (a), (b), (c) and (d) always being 100% by weight. The urea group containing thixotropic agent is prepared by reacting a compound selected from the group consisting of polyisocyanates and mixtures thereof, with an aliphatic monoamine selected from the group consisting of primary amines, secondary amines, water, and mixtures thereof, in the presence of the polyacrylate resin, to form a dispersion of the urea group containing thixotropic agent and the polyacrylate resin.
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