초록

Curing of autodeposited coatings by treatment with water or steam.

대표청구항 ▼

1. A process for curing an uncured autodeposited coating comprising contacting a metallic surface with an autodepositing composition having resin solids dispersed in the aqueous phase of said composition to form on said surface an uncured autodeposited coating in the form of resin solids adhered the

1. A process for curing an uncured autodeposited coating comprising contacting a metallic surface with an autodepositing composition having resin solids dispersed in the aqueous phase of said composition to form on said surface an uncured autodeposited coating in the form of resin solids adhered thereto and subjecting said uncured autodeposited coating to steam or to water having a temperature of about 70° F. to about 212° F. for a period of time sufficient to cure said coating. 2. A process according to claim 1 wherein said coating is cured by immersion in water at a temperature of about 70° F. to about 212° F. 3. A process according to claim 1 wherein said coating is cured by treating it with steam. 4. A process according to claim 1 including rinsing residuals from said coating and curing said coating simultaneously by spraying said coating with hot water or immersing it into a hot water bath. 5. A process according to claim 1 wherein said coating is cured for a period of time of about 5 seconds to about 5 minutes at a temperature of about 185° F. to about 212° F. 6. A process according to claim 5 wherein said period of time is no longer than about 2 to 3 minutes. 7. A process according to claim 1 wherein said coating is immersed into water having a temperature of about 185° F. to about 212° F. for a period of time of about 5 to about 30 seconds. 8. A process according to claim 1, 2, 3, 4, 5, 6 or 7 wherein said coating comprises a resin having a Tg of no greater than about 140° F. 9. A process according to claim 8 wherein said coating comprises a resin having a Tg of no greater than about 100° F. 10. A process according to claim 8 wherein said coating comprises a resin having a Tg of no greater than about 85° F. 11. A process according to claim 3 wherein said steam is at atmospheric pressure. 12. A process according to claim 1 in which said autodeposited coating consists essentially of an internally stabilized vinylidene chloride copolymer. 13. A process according to claim 1 in which said autodeposited coating consists essentially of an externally stabilized vinylidene copolymer having a vinylidene chloride content in excess of 50 wt. %. 14. A process according to claim 12 or 13 wherein said copolymer is crystalline. 15. A process according to claim 1 wherein said coating consists essentially of an acrylic or alkyl-substituted acrylic resin. 16. A process according to claim 1 including forming said autodeposited coating on a metallic substrate by immersing the substrate in an autodepositing composition which includes hydrofluoric acid and ferric iron as activating ingredients. 17. A process according to claim 1 wherein said autodeposited coating is adhered to a ferriferous surface. 18. A process according to claim 16 wherein ferric iron is present in said composition in the form of ferric fluoride. 19. A process according to claim 18 wherein said substrate is a ferriferous substrate. 20. A process for curing an uncured autodeposited coating comprising: immersing a metallic surface in an autodepositing composition consisting essentially of hydrofluoric acid, ferric fluoride and dispersed in the aqueous phase of said compositioon internally stabilized, crystalline resin solids comprising at least about 80 wt. % of vinylidene chloride and having a Tg below room temperature; forming on said surface an uncured autodeposited coating having resin solids of said composition adhered thereto; and immersing said surface having thereon said uncured autodeposited coating in hot water having a temperature of 100° F. or more for a period of time sufficient to cure said coating. 21. A process according to claim 20 wherein the temperature of the water is about 185° F. to about 212° F. and the surface is immersed therein for a period of time of no longer than about 2 to 3 minutes. 22. A process according to claim 20 or 21 wherein said surface is a ferriferous surface. 23. A process according to claim 22 wherein said uncured coating is rinsed with water to remove therefrom residuals of said composition prior to immersing said surface in said hot water.