摘要 |
<p>The present invention relates to a composition for coating a metal substrate which is intended to be fabricated and overcoated, wherein the binder comprises an acqueous silica sol having a SiO2/M2O mole ratio, with M representing the total of alkali metal and ammonium ions, of at least 6:1, and wherein the ratio of the pigment volume concentration to the critical pigment volume concentration is smaller than 1.</p> |