A rust preventive composition including (a) a silicic acid compound and (b) an aromatic amine-based condensation product is provided, which is effective in preventing a Zn-based metallic coating from rusting. Rusting is prevented by forming a coating film containing the components (a) and (b) on the surfaces of the Zn-based metallic coating formed on a base such as a metal plate. The resulting coating film exhibits an excellent corrosion resistance, gives no fear of a health problem such as carcinogenesis and provides a desirable black or blackish appearance to a metal surface. In an embodiment wherein a second coating film containing a silicic acid compound is formed on the first coating film, the corrosion resistance is further improved.
                            本发明提供了一种防锈组合物,其中包括(a)
硅酸化合物和(b)芳香胺基缩合产物,可有效防止
锌基
金属涂层生锈。通过在
金属板等基底上形成的
锌基
金属涂层表面上形成一层含有 (a) 和 (b) 组分的涂膜来防止生锈。形成的涂膜具有优异的耐腐蚀性,不会产生致癌等健康问题,并为
金属表面提供理想的黑色或微黑色外观。在一个实施方案中,在第一层涂膜上形成了含有
硅酸化合物的第二层涂膜,从而进一步提高了耐腐蚀性。