Coating processes – With post-treatment of coating or coating material – Heating or drying
Reexamination Certificate
2002-08-02
2004-06-22
Barr, Michael (Department: 1762)
Coating processes
With post-treatment of coating or coating material
Heating or drying
C427S301000, C427S304000, C148S240000, C148S243000
Reexamination Certificate
active
06753039
ABSTRACT:
FIELD OF THE INVENTION
The instant invention relates to a process for forming a deposit on the surface of a metallic or conductive surface. The process employs a process to deposit, for example, a mineral containing coating or film upon a metallic, metal containing or an electrically conductive surface.
BACKGROUND OF THE INVENTION
Silicates have been used in electro cleaning operations to clean steel, tin, among other surfaces. Electro cleaning is typically employed as a cleaning step prior to an electroplating operation. Usage of silicates as cleaners is described in “Silicates As Cleaners In The Production of Tinplate” is described by L. J. Brown in February 1966 edition of Plating; European Patent No. 00536832/EP B1 (Metallgesellschaft A G); U.S. Pat. Nos. 5,902,415, 5,352,296 and 4,492,616.
Processes for electrolytically forming a protective layer or film by using an anodic method are disclosed by U.S. Pat. No. 3,658,662 (Casson, Jr. et al.), and United Kingdom Patent No. 498,485.
U.S. Pat. No. 5,352,342 to Riffe, which issued on Oct. 4, 1994 and is entitled “Method And Apparatus For Preventing Corrosion Of Metal Structures” that describes using electromotive forces upon a zinc solvent containing paint; hereby incorporated by reference. U.S. Pat. Nos. 5,700,523, and 5,451,431; and German Patent No. 93115628 describes a processes for using alkaline metasilicates to treat metallic surfaces.
The disclosure of each of the previously identified references is hereby incorporated by reference.
SUMMARY OF THE INVENTION
The instant invention solves problems associated with conventional practices by providing an electroless or electrolytic process for treating metallic surfaces. The process employs a medium comprising at least one oxygen containing water soluble compound having a controlled and predetermined concentration, temperature and pH wherein the metallic surface is at least partially corroded or solubilized. As a result, the medium interacts with the metallic surface to form a new or modified surface having one or more improved properties.
The inventive process can form a surface comprising a mineral layer comprising an amorphous matrix surrounding or incorporating crystals upon the substrate. The characteristics of the mineral layer are described in greater detail in the copending and commonly assigned patent applications listed below.
A metallic surface that is treated (e.g., forming the mineral layer) by the inventive process can possess improved corrosion resistance, increased electrical resistance, heat resistance, flexibility, resistance to stress crack corrosion, adhesion to sealer, paints and topcoats, among other properties. The improved heat resistance broadens the range of processes that can be performed subsequent to forming the inventive layer, e.g., heat cured topcoatings, stamping/shaping, riveting, among other processes. The corrosion resistance can be improved by adding a dopant to the silicate medium, using a rinse and/or applying at least one sealer/topcoating.
The inventive process is a marked improvement over conventional methods by obviating the need for solvents or solvent containing systems to form a corrosion resistant layer, e.g., a mineral layer. In contrast, to conventional methods the inventive process can be substantially solvent free. By “substantially solvent free” it is meant that less than about 5 wt. %, and normally less than about 1 wt. % volatile organic compounds (V.O.C.s) are present in the electrolytic environment.
The inventive process is also a marked improvement over conventional methods by reducing, if not eliminating, chromate and/or phosphate containing compounds (and issues attendant with using these compounds such as waste disposal, worker exposure, among other undesirable environmental impacts). While the inventive process can be employed to enhance chromated or phosphated surfaces, the inventive process can replace these surfaces with a more environmentally desirable surface. The inventive process, therefore, can be “substantially chromate free” and “substantially phosphate free” and in turn produce articles that are also substantially chromate (hexavalent and trivalent) free and substantially phosphate free. The inventive process can also be substantially free of heavy metals such as chromium, lead, cadmium, barium, among others. By substantially chromate free, substantially phosphate free and substantially heavy metal free it is meant that less than 5 wt. % and normally about 0 wt. % chromates, phosphates and/or heavy metals are present in a process for producing an article or the resultant article.
DETAILED DESCRIPTION
The instant invention relates to a process for depositing or forming a beneficial surface (e.g., a mineral containing coating or film) upon a metallic surface. The process contacts at least a portion of a metal surface with a medium comprising at least one oxygen containing water soluble compound, e.g., containing soluble mineral components or precursors thereof, having controlled concentration, temperature and pH wherein the metal surface is at least partially corroded or solubilized. By “oxygen containing water soluble compound” it is meant to refer to at least one member selected from the group of borates, aluminates, zironcates, titanates, molybdates, tungstenates, stannates, nitrates, sulfates, vanadates, cerium hydrates, water soluble manganese and magnesium compounds, nickel compounds, cobalt compounds, among other oxygenated water soluble compounds capable of interacting with a metal surface. By “mineral containing coating”, “mineralized film” or “mineral” it is meant to refer to a relatively thin coating or film which is formed upon a metal surface wherein at least a portion of the coating or film comprises at least one metal containing mineral, e.g., an amorphous phase or matrix surrounding or incorporating crystals comprising a zinc disilicate. Mineral and Mineral Containing are defined in the previously identified Copending and Commonly Assigned Patents and Patent Applications; incorporated by reference.
By “metal containing”, “metal”, or “metallic”, it is meant to refer to sheets, shaped articles, fibers, rods, particles, continuous lengths such as coil and wire, metallized surfaces, among other configurations that are based upon at least one of metals and alloys including a metal having a naturally occurring, or chemically, mechanically or thermally modified surface. Typically a naturally occurring surface upon a metal will comprise a thin film or layer comprising at least one oxide, hydroxides, carbonates, sulfates, chlorides, among others. The naturally occurring surface can be removed or modified by using the inventive process.
The metal containing surface refers to a metal article or body as well as a non-metallic member having an adhered metal or conductive layer. While any suitable surface can be treated by the inventive process, examples of suitable metal surfaces comprise at least one member selected from the group consisting of galvanized surfaces, sheradized surfaces, zinc, iron, steel, brass, copper, nickel, tin, aluminum, lead, cadmium, magnesium, alloys thereof such as zinc-nickel alloys, tin-zinc alloys, zinc-cobalt alloys, zinc-iron alloys, among others. If desired, the mineral layer can be formed on a non-conductive substrate having at least one surface coated with a metal, e.g., a metallized polymeric article or sheet, ceramic materials coated or encapsulated within a metal, among others. Examples of metallized polymer comprise at least one member selected from the group of polycarbonate, acrylonitrile butadiene styrene (ABS), rubber, silicone, phenolic, nylon, PVC, polyimide, melamine, polyethylene, polyproplyene, acrylic, fluorocarbon, polysulfone, polyphenyene, polyacetate, polystyrene, epoxy, among others. Conductive surfaces can also include carbon or graphite as well as conductive polymers (polyaniline for example).
The metal surface can possess a wide range of sizes and configurations, e.g., fibers, coils, sheets including perforated acoustic panels, chopped wires, draw
Haran Bala
Heimann Robert L.
Popov Branko
Slavkov Dragan
Barr Michael
Boyer Michael K
Elisha Holding LLC
LandOfFree
Electrolytic and electroless process for treating metallic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrolytic and electroless process for treating metallic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrolytic and electroless process for treating metallic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3343132