PURPOSE: To enable to obtain excellent adhesiveness even when paint is applied within a short time after being prepared, in coating a cold-rolled steel sheet, by repeating the agitation of the paint where zinc powder is dispersed into a binder in company with standing periods, and then applying the paint.
CONSTITUTION: After a cold-rolled steel sheet is degreased and acid-pickled, an aqueous solution for stabilizing a film on the metallic surface is applied to it so that the total amount of chromium contained in the film is controlled at 30mg/m3, to form an underbedding fim. Thereafter, epoxy paint containing zinc powder at a ratio of 85wt% based on a dry paint film is applied to obtain an anticorrosive steel sheet. Hence, the zinc powder-contg. paint must be matured for about 6 days until its application after preparation; otherwise the excellent adhesiveness of the paint film would not be obtained. However, when the paint is repeatedly agitated, e.g. once a day for on hour or twice a day for one hour every cycle in company with a standing period, to uniformly disperse the zinc powder, the maturning period can be shortened to about 2 days.
TAKAMURA HISAO
MAEDA YASUHARU
YOKOYAMA MASATOSHI
SUZUKI MASARU
WAKABAYASHI KOUJI
