Phosphate coatings for metal surfaces

• Main Authors: ENDO, KOETU, TOKUYAMA, AKIO, SOBATA, TAMOTSU
• Format: Patent
• Language: English; French; German
• Published: 05.09.1990
• 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

A process for phosphating a metal surface which comprises treating the metal surface with an acidic aqueous phosphate solution containing:- (a) from 0.1 to 2.0g/l of zinc ion; (b) from 5 to 40g/l of phosphate ion; (c) a phosphating accelerator comprising: (1) from 0.01 to 0.5g/l of nitrite ion, (11) from 0.05 to 5g/l of m-nitrobenzene sulfonate ion, or (iii) from 0.5 to 10g/l of hydrogen peroxide (base on 100% H2O2); and (d) from 0.01 to 10g/l of colloidal particles having an isolectric point of 3 or less and an average particle diameter of 0.1 or less.