Verfahren zur Herstellung von Einkomponenteneinbrennlacken auf Acrylharzbasis

摘要

1,202,777. Lacquer. FARBENFABRIKEN BAYER A.G. 26 Jan., 1968 [27 Jan., 1967], No. 4204/68. Heading C3P. A one-component stoving lacquer is produced by subjecting a vinyl monomer to a mixed polymerization with a monomer containing one alcoholic hydroxyl group and one ethylenic double bond and a #-isocyanatoethyl methacrylate or acrylate masked with an oxime. Suitable monomers are the amides and nitriles of methacrylic or acrylic acid, substituted styrenes, vinyl acetate, or more preferably esters of methacrylic or acrylic acid and styrene. Suitable alcoholic hydroxyl group containing monomers are allyl alcohol, oxyalkylated p-isopropenylphenol and N-methylol methacrylamide on acrylamide, or more preferably methacrylic or acrylic acid hydroxyl alkyl esters. The oxime adducts may be prepared by reacting #-isocyanato-ethyl acrylate or methacrylate with an oxime of an aldehyde or ketone. In the examples: (1) ethyl acrylate, styrene, 2-hydroxypropyl methacrylate and #-isocyanatoethyl methacrylate masked with acetoxime, are heated in xylene under nitrogen in the presence of azodiisobutyronitrile and tert-dodecyl mercaptan, and the resulting polymer solution is mixed with pigments to form a lacquer; (2) ethyl acrylate, butyl acrylate, styrene, methyl methacrylate, 2-hydroxypropyl methacrylate, and #-isocyanatoethyl acrylate masked with acetoxime are polymerized in the presence of dibenzoyl peroxide; (3) ethyl acrylate, styrene, 2-hydroxypropyl methacrylate, the acetoxime adduct of #-isocyanatoethyl methacrylate, dimethylformamide, sodium pyrosulphite, sodium lauryl sulphate potassium persulphate and water are heated to form a polymer dispersion from which lacquer films may be produced.