| 摘要 |
PURPOSE:To improve water-resistant secondary adhesiveness and corrosion resistance when a chemical conversion film is subjected to electrodeposition painting thereon by adding condensed phosphoric acid to a phosphate film treating agent so that the chemical conversion film particles applied with the titled treating agent obtd. is such a manner are extremely fined. CONSTITUTION:The titled treating agent contg. 0.2-1.5g/l zinc ion, 5-30g/l phosphate ion, and 1-30g/l condensed phosphoric acid is prepd. The above- mentioned condensed phosphoric acid is preferably >=1 kinds among pyrophosphoric acid, methaphosphoric acid, polyphosphoric acid and the salts thereof and phosphorus pentoxide. The titled treating agent further contains preferably nitric acid ion or hydrochloric acid ion of an oxidizing agent or contains >=1 kinds among 0.3-3g/l Ni ion, 0.5-10g/l nitric acid ion, 0.6-3g/l Mn ion and 0.05-2g/l ClO3 ion.
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