| 摘要 |
1,171,240. Alkyd based aqueous stoving lacquers. FARBENFABRIKEN BAYER A.G. 21 Dec., 1967 [22 Dec., 1966], No. 58193/67. Addition to 1,095,953. Heading C3R. Aqueous stoving lacquers are made by (a) esterifying 1 mol. of a dicarboxylic acid or anhydride thereof with 1À0-1À3 mols. of a trihydric alcohol (or a mixture thereof with a dihydric alcohol or other polyhydric alcohol) in the presence of a fatty acid to produce an alkyd resin of hydroxyl number 90 to 300 and acid number below 15, (b) reacting this alkyd resin with an alkyl substituted tetrahydrophthalic anhydride to give a semi-ester of the alkyd with a hydroxyl number of 60 to 200 and an acid number of 30 to 80 (c) reacting the semi-ester with an amine to give a water-soluble salt and (d) adding water. The lacquers may also contain water-immiscible organic solvents, aminoplasts or pigments. Specified for the substituted tetrahydrophthalic anhydrides are the 3- and 4- methyl, the 3-ethyl and the 3: 6-dimethyl substituted acids. Specified other components are as in Specification 1,095,953. In an example an alkyd resin from phthalic anhydride, pentaerythritol and a mixture of C 6 to C 12 saturated fatty acids was reacted with 4-methyl-tetrahydrophthalic anhydride to give the semi-ester which was then dissolved in ethylene glycol monobutyl ether and mixed with dimethyl ethanolamine and water. A lacquer was produced from the aqueous solution of the resin salt by adding a methylated melamine-formaldehyde condensate and titanium dioxide.
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