Anti-fouling coating for turbomachinery

• US 5,985,454 A
• Filed: 10/14/1997
• Issued: 11/16/1999
• Est. Priority Date: 02/05/1990
• Status: Expired due to Term

• Current Assignee: Sermatech International, Inc. (Linde Plc)
• Original Assignee: Sermatech International, Inc. (Linde Plc)
• Inventors: Mosser, Mark F., McMordie, Bruce G.
• Primary Examiner(s): Wilson, Donald R.
• Application Number:
  US08/949,812
• Time in Patent Office: 763 Days
• Field of Search: 428/413, 428/457, 428/458, 428/418, 428/461, 428/463, 428/469, 428/472.3, 428/472.2
• US Class Current: 428/413
• CPC Class Codes: B05D 5/086 having an anchoring layer
• CPC Class Codes: B05D 7/14 to metal, e.g. car bodies involving a chemical reaction between the metal and the coating C23
• CPC Class Codes: C09D 5/08 Anti-corrosive paints
• CPC Class Codes: C09D 5/103 containing Al
• CPC Class Codes: C23C 24/08 by application of heat or pressure and heat C23C24/04 takes precedence
• CPC Class Codes: C23C 28/00 Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
• CPC Class Codes: C23C 28/044 coatings specially adapted for cutting tools or wear applications
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31529 Next to metal
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31692 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31699 Ester, halide or nitrile of addition polymer

Abstract

Multilayered coatings comprising a sacrificial primer layer, a non-sacrificial second layer, and a polymer topcoat are disclosed.

Claims

1. A coating which comprises

a first cured layer of an adherent aluminum- or aluminum alloy-filled ceramic containing inorganic phosphate in contact with a surface, the first layer being either

(1) filled with an aluminum alloy or a pure aluminum powder and having been made galvanically sacrificial and having an electrical resistance of less than 15 ohms measured with probes 1" apart,

a second cured layer in contract with the first layer, which second layer contains an inorganic phosphate or silicate binder and finely divided aluminum or aluminum alloy powder which second layer is not galvanically sacrificial greater than 15 ohms measured with probes 1" apart, and

a cured top layer which comprises a thermally stable organic polymer sealer.

2. The coating of claim 1 in which the first layer is filled with finely divided particulate aluminum alloy which layer is galvanically sacrificial to the metal surface without being made electrically conductive.

3. The coating of claim 1 in which the first layer has an electrical resistance of less than 15 ohms measured with probes 1" apart and is galvanically sacrificial due to a post-thermal or mechanical treatment.

4. The coating of claim 3 in which the galvanically sacrificial property of first layer is imparted by the mechanical treatment.

5. The coating of claim 3 in which the first layer has been subjected to a post-thermal treatment.

6. The coating of claim 2 in which the aluminum alloy is an aluminum-magnesium alloy.

7. The coating of claim 1 in which the first layer is between about 32 to 44 μ

m thick.

8. The coating of claim 1 in which the first layer contains a compound selected from the group consisting of chromate, molybdate, vanadate and tungstate, or the metal salts thereof.

9. The coating of claim 1 in which either or both of the first two inorganic layers are free of molybdenum and/or chromium salts.

10. The coating of claim 1 in which the second layer is between about 32 to 44 μ

m thick.

11. The coating of claim 1 in which the organic polymer sealer is selected from the group consisting of epoxy modified polyamide-imide, polyamide-imide, polyphenylene sulfide polytetrafluoroethylene, polyvinylidene fluoride, or fluorinated ethylene/propylene copolymer.

12. The coating of claim 1 wherein the coating comprises an additional, thermally stable organic polymer layer, which is sandwiched between the second and a cured top layer, and is of a different composition than the top layer.