| 摘要 |
PURPOSE:To subject an iron or steel structure to corrosion preventive coating to an extra thick film thickness by immersing the iron or steel structure into an electrodeposition bath of a cation electrodeposition paint of epoxy resin contg. a specific ratio of specific alcohol and successively increasing the voltage from a low to adequate voltage. CONSTITUTION:The electrodeposition bath having 8-20wt% concn. of solid content in the bath is prepd. by using 10-30pts.wt. monohydric alcohol of >=1 kinds of alkanol having 130-200mol.wt. and ether alcohol having 110-200mol.wt. and 100pts.wt. cation electrodeposition paint of epoxy resin. The iron or steel structure is immersed into the above-mentioned electrodeposition bath and the conduction of current is started at <=100V initial impressed voltage. The voltage is then increased at a rate of 50-200V/min and the above-mentioned structure is subjected to electrodeposition painting for 10-50min under the conditions of the range enclosed by the quadrilateral connecting the four points (8, 200), (8, 380), (20, 160), (20, 340) with straight lines when the concn. of solid content is the bath (wt%) is taken at the axis of abscissa and the applied voltage (V) at the axis of ordinate. The iron or steel structure is thereafter pulled out of the bath and is subjected to baking and drying. The corrosion preventive coated film having an extra large thickness of about 80-150mu and good quality is thus formed.
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