| 摘要 |
A pigmented, thermosetting organic solvent solution coating composition having improved capacity to resist acid rain is disclosed in which a resinous polyepoxide, a phenoplast resin cross-linking agent for said polyepoxide (preferably a xylolol-formaldehyde condensate), a phosphoric acid ester catalyst, a chromium-containing pigment providing resistance to corrosion, and a clay having the capacity to fix phosphate, are combined. For package stability, the catalyst is the reaction product of ortho phosphoric acid with an aliphatic diol, there being sufficient hydroxy in said diol to provide at least 1 equivalent of hydroxy for each acid equivalent in said phosphoric acid. These coatings are applied as a prime coating which is baked to remove solvents and provide a dry film without removing the phosphoric acid contained therein. The dry primer is then overcoated with a topcoat, and the doubly coated substrate is baked to cure the first coating.
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