| 摘要 |
<p>1476240 Phosphating Al or Al alloy surfaces PYRENE CHEMICAL SERVICES Ltd 30 Sept 1974 [4 Oct 1973] 42313/74 Heading C7U Al or Al alloy is phosphated using an aqueous solution (pH 1À2 to 5À5) containing phospheric acid or an alkali metal or ammonium phosphate, and a (0À1 to 10 g./l.) of tannin or tannic acid in the form of a metal salt of e.g. Ti, Zr, Cr, Mo, W, V, Fe, Co, Ni or complex salts made from hydrofluosolisic, hydrofluoboric or hydrofluoric acids. The ratio of metal to tannin being 1 to 50:100. The solution may also contain pyro-tripoly-or hexametaphosphoric acids or an organophosphoras compound, e.g. phytic, nitrodiethanolethylene sulphuric, 2-hydroxyethyl-methacryl-1-acid phosphonic, 2-ethyl-hexyl acid phosphonic, or ethane-1- hydroxy-1, 1-diphosphonic acids. HF, fluobric, fluosilicic, hydrofluotitanic, and hydrofluozirconoc acids may also be added.</p> |
