| 摘要 |
1425871 Phosphating ferrous surfaces NIPPON PAINT CO Ltd 22 Nov 1973 [22 Nov 1972] 54148/73 Heading C7U A ferrous surface is contacted with an aqueous solution containing 0.5 to 80 weight 1 vol. % of phosphoric acid, and then without water rinsing the surface is contacted with an aqueous solution (pH 1 to 9) containing either (a) phosphoric acid and a substance which reacts with the phosphoric acid to give a water soluble salt or (b) a solution of the water soluble salt. The coated surface is dried without rinsing. The phosphoric acid used in the first step may be ortho-, pyro- or tripolyphosphoric acids, and it may contain an inhibitor, e.g. amines or thiourea or stannic or arsenic compounds. The substance used in the second step may be ammonia, ammonium hydroxide, hydroxylamine, tetraalkly ammonium hydroxide, alkylamine, di-or tri-alkylamine, or an alkali metal or oxide or hydroxide thereof. The solution used in the second step may also include a stannous compound, and an oxidizing agent. |
