Compositions – Electrically conductive or emissive compositions – Free metal containing
Reexamination Certificate
1999-07-23
2001-05-15
Kopec, Mark (Department: 1751)
Compositions
Electrically conductive or emissive compositions
Free metal containing
C252S500000, C252S513000, C427S180000, C427S327000, C427S384000
Reexamination Certificate
active
06231789
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains to a corrosion prevention system and method of producing the same, and more specifically to a system for protecting a metal substrate from corrosion utilizing a cathodic coating comprising at least one inherently conductive polymer and sacrificial metal particles.
2. Description of the Related Art
One type of coating used to protect metals from corrosion is called a barrier coating. Barrier coatings function to separate the metal from the surrounding environment. Some examples of barrier coatings include paints and nickel and chrome plating. An effective barrier coating includes a layer of the conductive polymer polyaniline. However, as with all barrier coatings, holidays in the barrier coatings leave the metal substrate susceptible to corrosion. Electrochemically active barrier coatings, such as nickel, chrome, and conductive polyaniline layers, can actually accelerate corrosion of underlying metals at holidays in the coating.
Another type of coating used to protect metal substrates are call sacrificial coatings. The metal substrate is coated with a material that reacts with the environment and is consumed in preference to the substrate it protects. These coatings may be further subdivided into chemically reactive, e.g., chromate coatings, and electrochemically active, or galvanically active, e.g. , aluminum, cadmium, magnesium, and zinc. The galvanically active coatings must be conductive and are commonly called cathodic protection.
In the art, a major difficulty has been the creation of a coating that protects like a cathodic system but is applied with the ease of a typical barrier coating-system. Furthermore, there are many environmental drawbacks with both traditional barrier and sacrificial methods, from use of high levels of volatile organic compounds to expensive treatment of waste waters produced by plating and subsequent surface preparation for top-coating processes.
The present invention contemplates a new and improved coating system and method of producing the same which overcomes the foregoing difficulties and others while providing better and more advantageous overall results.
SUMMARY OF THE INVENTION
In accordance with the present invention, a new and improved cathodic corrosion resistant coating system is provided which may be easily applied in an environmentally friendly, efficient, safe and cost effective way to a metal substrate.
More particularly, the coating system utilizes at least one inherently conductive polymer in combination with galvanically anodic metals dispersed in a resin matrix and applied to a metal substrate to create a cathodic coating which is corrosion resistant.
In accordance with the invention, a coating composition is provided for use in protecting metallic substrates from corrosion comprising at least one inherently conductive polymer and metal particles anodic to the substrate dispersed in a resin base.
According to another aspect of the invention, a method of protecting a metallic substrate from corrosion is provided including the steps of preparing a surface of the substrate; coating the prepared surface with a coating composition comprising an inherently conductive polymer and metal particles anodic to the substrate dispersed in a resin base; and, curing the coating composition to form a corrosion resistant coating.
According to another aspect of the invention, a method of preparing a coating composition is provided including the steps of dispersing at least one inherently conductive polymer and metal particles anodic to the intended substrate in a resin base material.
According to yet another aspect of the invention, the coating composition may be a high solids formulation.
According to yet another aspect of the invention, the coating composition may be a TV curable formulation.
According to yet another aspect of the invention, the coating composition may be a powder coating formulation.
One advantage of the present invention is that the claimed coating can utilize most conventional methods for application, including dipping, brushing, rolling, spraying, fluidized bed, electrostatic powder, and thermally sprayed powder.
Another advantage of the present invention is the reduction or elimination of the emission of volatile organic compounds into the atmosphere.
Another advantage is the elimination of the rinsing processes associated with galvanizing and plating operations, surface preparation for top-coating, and subsequent waste water treatment.
Another advantage is the reduction of the levels of zinc, lead, cadmium, and other heavy metals in water systems and soil due to weathering of galvanized and plated structures.
Another advantage of the present invention is the cost effectiveness of the process. The coating may be produced at a reasonable cost and applied with existing application systems. Use of the inventive coating system will extend service life and reduce the costs associated with corrosion maintenance.
Still other benefits and advantages of the invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification.
REFERENCES:
patent: 3546155 (1970-12-01), Chandler
patent: 3748172 (1973-07-01), Speirs et al.
patent: 3862851 (1975-01-01), Speirs et al.
patent: 4086153 (1978-04-01), Ariga et al.
patent: 4130469 (1978-12-01), McGinniss
patent: 4140816 (1979-02-01), McGinniss
patent: 5069820 (1991-12-01), Jen et al.
patent: 5160457 (1992-11-01), Elsenbaumer
patent: 5217649 (1993-06-01), Kulkarni et al.
patent: 5281363 (1994-01-01), Shacklette et al.
patent: 5290483 (1994-03-01), Kulkarni et al.
patent: 5456862 (1995-10-01), Kwan-Yen et al.
patent: 5532025 (1996-07-01), Kinlen et al.
patent: 5567355 (1996-10-01), Wessling et al.
patent: 5645890 (1997-07-01), MacDiarmid et al.
patent: 5648416 (1997-07-01), Miller et al.
patent: 5658649 (1997-08-01), Wrobleski et al.
patent: 5853621 (1998-12-01), Miller et al.
patent: 5871671 (1999-02-01), Kinlen et al.
patent: 7103185 (1996-10-01), None
patent: 7-103185 (1996-10-01), None
Geer Steven R.
Hawkins Todd R.
Emerson Roger D.
Emerson & Skeriotis
Geotech Chemical Co., LLC
Kopec Mark
Mruk Brian P.
LandOfFree
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