| 摘要 |
PURPOSE:To enable harmless chemical forming treatment with low public pollution by treating a tin plated can with an aqueous solution containing an orthophosphoric acid type component and a phytinic acid type component in a specific concn. respectively and having a pH in a specific range. CONSTITUTION:As an orthophosphoric acid type component, there are orthophosphoric acid and salts thereof (Na salt, K salt, Li salt or the like) and at least one thereof is selected in a range of 0.5-10g/l, pref., 1-6g/l as PO4. Further, as a phytinic acid type component, there are phytinic acid and salts thereof (a salt, K salt, Li salt or the like) and at least one thereof is selected in a range of 0.2-2g/l, pref., 0.4-1.5g/l as PO4. Further, a pH is adjusted to 3-5, pref., 3-4. Other than those essential components, if necessary, sodium chlorate and/or potassium chlorate can be added in a range of 0.1-50g/l, pref., 0.5-10g/l. |
