| 摘要 |
PURPOSE:To improve the close adhesiveness of a paint, by a method wherein a chromate film is formed by coating type chromate treatment and, thereafter, an aqueous chromic anhydride solution with a specific temp. and concn. is applied to said film and subjected to roll squeezing. CONSTITUTION:A coating type chromate treating solution prepared by adding a colloidal substance or a water-soluble or water dispersible high-molecular substance to an aqueous chromic anhydride solution is applied to a zinc or zinc alloy plated steel plate and dried to form a chromate film. An aqueous solution containing 0.5-20g/L of chromic anhydride and heated to a room temp.-40 deg.C is applied to the chromate treated steel plate and succeedingly subjected to roll squeezing and dried by hot air. |
