| 摘要 |
1,270,851. Alkyd resin lacquer compositions. FARBENFABRIKEN BAYER A.G. 3 June, 1969 [7 June, 1968], No. 27958/69. Heading C3R. [Also in Division C7] A lacquer composition suitable for electrodeposition comprises phenol and/or an alkylphenol and an aqueous solution of an ammonium or amine salt of an oil-modified alkyd resin which has been provided with free carboxyl groups by reaction with tetrahydrophthalic acid or an alkyl or endomethylene derivative thereof, the acid resin also having been modified by the introduction of cross-linking alkoxymethylamino groups, e.g. by treatment with an alkoxymethyl isocyanate. The phenol content of the composition is preferably 1 to 10% by weight and the pH 7À5 to 8À5. Organic solvents miscible or partly miscible with water, e.g. ethylene glycol monoalkyl ethers or dimethylformamide, and fillers or pigments, e.g. TiO 2 , may also be present. A metal article is coated by dipping it in the composition, passing a current with the article as anode, preferably at 140 to 300 V., and drying and stoving the article. The example describes the use of a composition based on a pentaerythritol-phthalic anhydridefatty acid resin which is treated with tetrahydrophthalic anhydride, then with triethylamine, then with methoxymethyl isocyanate before addition of the phenol and water. |
