Patent EA-000872-B1 (EA)
Title: Composition and method for treatment of phosphated metal surfaces
Inventor: AFFINITO JOHN C
IPC: C23C22/83
Filed: 1997-02-21
Abstract: 1. A rinse solution for treatment of phosphated metal surfaces comprising an aqueous solution of a Group IVA metal ion, selected from the group consisting of zirconium, titanium, hafnium and mixtures thereof, and a phenolic resin characterised in that the resin is a resole phenolic and is present in a concentration in the range 0.01 to 0.40% w/w, the Group IVA metal ion is present in a concentratio in the range 0.00035 to 0.0050% w/w, and the pH is in the range 3.5 to 5.1. 2. A rinse solution as defined in claim 1 wherein the group IVA metal ion concentration is in the range 0.00035 to 0.0016% w/w, preferably in the range 0.00065 to 0.0050% w/w. 3. A rinse solution as defined in claim 1 or claim 2 wherein the group IVA metal ion concentration is in the range 0.00035 to 0.0010% w/w, the phenolic resin concentration is in the range 0.01 to 0.077% w/w, and the pH is in the range 4.0 to 5.1/ 4. A rinse solution as defined in any of the preceding claims in which the group IVA metal ion comprises titanium. 5. A rinse solution as defined in any of the preceding claims in which the group IVA metal ion comprises zirconium. 6. A rinse solution as defined in any preceding claim in which the group IVA metal ion comprises hafnium. 7. A rinse solution as defined in claim 6 wherein the hafnium ion concentration is in the range 0.0008 to 0.0010% w/w, the phenolic resin concentration is in the range 0.01 to 0.077% w/w and the pH is in the range 4.0 to 5.1. 8. A rinse solution as defined in any of claims 1 to 3 which comprises at least two groups IVA metal ions, the first of which is present at a concentration in the range 0.00035 to 0.0016% w/w and the second of which is present at a concentration in the range 0.00065 to 0.0011% by weight. 9. A rinse solution according to claim 8 in which the resin is present at a concentration in the range 0.01 to 0.077% w/w. 10. A solution according to claim 8 or claim 9 which has a pH in the range 4.0 to 5.1. 11. A rinse solution as defined in any preceding claim wherein the Group IVA metal ion is from a Group IVA metal ion source selected from the group consisting of hexafluorozirconic acid, hexafluorotitanic acid, hafnium oxide, titanium oxysulfate, titanium tetrafluoride, zirconium sulfate and mixtures thereof. 12. A method of treating a metal phosphated surface by contacting it with a rinse solution according to any preceding claim. 13. A method according to claim 12 in which the solution is contacted with the surface by spraying. 14. A method according to claim 12 in which the solution is contacted with the surface by dipping the surface in a bath of the solution. 15. A method according to any of claims 12 to 14 in which the solution is at a temperature in the range 20 to  70 degree C. 16. A method according to any of claims 12 to 15 in which the coated surface is dried at a raised temperature. 17. A method according to any of claims 12 to 16 which involves a pretreatment step in which the metal surface is conversion coated, preferably phosphate conversion coated, and the conversion coated surface is contacted with the rinse solution. 18. A method according to any of claims 12 to 17 in which the treated surface is subsequently coated with a siccative coating.