| 摘要 |
<p>A coating type chromate conversion coating composition comprising as essential components (A) 5 SIMILAR 500g/l as solid of an aqueous emulsion of polymer particles having an average grain diameter of 0.1 SIMILAR 3 mu m which are crosslinked or whose glasstransition point is within a range of 15 DEG SIMILAR 110 DEG C, the said polymer being prepared by an emulsion polymerization of at least one alpha , beta -ethylenically unsaturated monomer in the presence of particular protective colloid defined in the specification, (B) 2 SIMILAR 250g/l as solid of a polyacrylic acid or acrylic copolymer, (C) 5 SIMILAR 500g/l as Cr of a water soluble chromium compound, 30 SIMILAR 50 wt% of the total chromium contained being trivalent chromium, and (D) 5 SIMILAR 1,000g/l of metal oxide microparticles having an average diameter of 0.1 to 20 mu m, selected from MnO, TiO2 Fe2O3, Fe3O4, CrO3, Al2O3, ZnO, PbO2 and CuO, the solid weight ratio of (A) to (C) being 10:1 to 1:5, the weight ratio of (D) to (C) being 5:1 to 1:10 and pH of the composition being 1 SIMILAR 3. The present coating composition isspecifically useful for the pre-treatment of metal substrate for coating, giving excellent corrosion-resistance and coating adhesive properties etc.</p> |
