| 摘要 |
PURPOSE:To improve the adhesion and corrosion resistance of the paint film on a galvanized steel plate, by phosphating the galvanized steel plate then treating the same with an aq. soln. contg. polyacrylic acid and arom. polyhydric alcohol. CONSTITUTION:The surface of a galvanized steel plate is degreased and hot rinsed, and is then subjected to ordinary phosphation. After hot rinsing in succession, the steel plate is coated thereon with an aq. soln. contg. 1X10<-3>g/l-5g/l polyacrylic acid and 0.5-10 times the content thereof arom. polyhydric alcohol such as tannic acid. The treatment is accomplished by coating said soln. at ordinary temp. - <=70 deg.C in such a way that the total org. matter stuck thereon attains 0.1-100mg/m<2>. The stable performance in the adhesion of paint film, the corrosion resistance after painting or the like is provided at a low cost by the above-mentioned pretreatment method. |
