CONCENTRATE COMPOSITION FOR CONVERSION TREATMENT OF HEXAVALENT CHROMIUM-FREE SURFACE ENHANCED IN STABILITY

• Main Authors: SUGIURA HISAHIRO, ITO MITSUHIRO, NAGATANI YASUHIRO, NOJIMA SHIGEHIKO
• Format: Patent
• Language: English
• Published: 31.01.2008
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PROBLEM TO BE SOLVED: To develop a concentrate composition for chemical conversion treatment represented by a trivalent chromate treatment superior in storage stability which does not generate gases during the time of storing as a concentrated liquid. SOLUTION: The generation of gases is prevented by any of following means: a means (i) of reducing the amount of malonic acid for preventing the oxidation/decomposition of the malonic acid by nitric acid, with hydroquinone; and a means (ii) of using only oxalic acid instead of the malonic acid. COPYRIGHT: (C)2008,JPO&INPIT