| 摘要 |
PURPOSE:To improve pitting resistance, corrosion resistance, etc., of coated film by coating aqueous barrier coat having a static glass transfer point at a specified temp. on the electrodeposition coating surface applied to a steel product, then coating intermediate coat and top coat thereon. CONSTITUTION:After treating previously a steel product with chemical conversion treatment using phosphate or chromate, it is further subjected to electrodeposition coating using a cationic or anionic electrodeposition paint. Then, an aq. compsn. consisting primarily of a water-soluble vehicle and water capable of forming coated film having 0--75 deg.C static glass transition point contg., if necessary, a tackifier and an org. solvent, is prepd. An aq. barrier coat is formed on the electrodeposition coated steel product by coating with the aq. compsn. Then, intermediate coat and top coat are applied thereto. Suitable intermediate coat is alkyd resin having <30% oil length, etc., and suitable top coat is aminoacryl resin, etc.
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