Weldable, coated metal substrates and methods for preparing and inhibiting corrosion of the same

• US 6,440,580 B1
• Filed: 12/01/1998
• Issued: 08/27/2002
• Est. Priority Date: 12/01/1998
• Status: Expired due to Fees

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Pawlik, Michael J., Nugent, Richard M. Jr., Gray, Ralph C., Berger, Valentin
• Primary Examiner(s): Thibodeau, Paul
• Assistant Examiner(s): ZACHARIA, RAMSEY E
• Application Number:
  US09/203,833
• Time in Patent Office: 1,365 Days
• Field of Search: 428/623, 428/626, 428/659, 428/411.1, 428/413, 428/416, 428/423.1, 428/500, 428/480, 428/522, 428/523, 428/474.4
• US Class Current: 428/623
• CPC Class Codes: B05D 2701/40 withstanding welding
• CPC Class Codes: B05D 7/16 using synthetic lacquers or varnishes
• CPC Class Codes: B23K 35/226 Non-corrosive coatings; Primers applied before welding
• CPC Class Codes: C08G 59/4071 phosphorus containing compounds
• CPC Class Codes: C08G 59/50 Amines
• CPC Class Codes: C08G 59/56 together with other curing agents
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• 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: Y10T 428/12549 Adjacent to each other
• CPC Class Codes: Y10T 428/1259 Oxide
• CPC Class Codes: Y10T 428/12799 Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31522 Next to metal
• CPC Class Codes: Y10T 428/31529 Next to metal
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31725 Of polyamide
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31938 : Polymer of monoethylenically unsaturated hydrocarbon

Abstract

The present invention provides a weldable, coated metal substrate having a pretreatment coating including a reaction product of at least one epoxy-functional material and at least one phosphorus-containing material or amine-containing material and a weldable coating having an electroconductive pigment and a binder deposited thereon.

Claims

1. A weldable, coated metal substrate comprising:

(a) a bare metal substrate;

(b) a pretreatment coating having less than 0.05 weight percent of chromium-containing materials, the pretreatment coating comprising a β

-hydroxy phosphorous ester that is the reaction product of at least one epoxy-functional material and a phosphorus-containing material deposited upon at least a portion of a surface of the metal substrate; and

(c) a weldable coating comprising an electroconductive pigment and a binder deposited upon at least a portion of the pretreatment coating.

2. The coated metal substrate according to claim 1, wherein the metal substrate comprises a ferrous metal.

3. The coated metal substrate according to claim 2, wherein the ferrous metal is selected from the group consisting of iron, steel, and alloys thereof.

4. The coated metal substrate according to claim 3, wherein the ferrous metal comprises steel selected from the group consisting of cold rolled steel, galvanized steel, electrogalvanized steel, stainless steel, and combinations thereof.

5. The coated metal substrate according to claim 1, wherein the metal substrate comprises a non-ferrous metal selected from the group consisting of aluminum, zinc, magnesium, and alloys thereof.

6. The coated metal substrate according to claim 1, wherein the epoxy-functional material is the condensation reaction product of an epihalohydrin with a polyhydric alcohol.

7. The coated metal substrate according to claim 1, wherein the phosphorus-containing material is selected from the group consisting of phosphoric acids, phosphonic acids, and mixtures thereof.

8. The coated metal substrate according to claim 1, wherein the reaction product is selected from the group consisting of epoxy esters of phosphoric acid, epoxy esters of phosphonic acid, and mixtures thereof.

9. The coated metal substrate according to claim 1, wherein the pretreatment coating further comprises at least one secondary amine.

10. The coated metal substrate according to claim 9, wherein the secondary amine is diisopropanol amine.

11. The coated metal substrate according to claim 1, wherein the pretreatment coating further comprises a fluorine-containing material.

12. The coated metal substrate according to claim 11, wherein the fluorine-containing material is selected from the group consisting of hydrofluoric acid, fluorosilicic acid, sodium hydrogen fluoride, potassium hydrogen fluoride, ammonium hydrogen fluoride, and mixtures thereof.

13. The coated metal substrate according to claim 1, wherein the pretreatment coating further comprises at least one Group IVB element-containing material.

14. The coated metal substrate according to claim 13, wherein the Group IVB element-containing material is a zirconium-containing material selected from the group consisting of fluorozirconic acid, potassium hexafluorozirconate, alkali salts of zirconium hexafluoride, amine salts of zirconium hexafluoride, and mixtures thereof.

15. The coated metal substrate according to claim 13, wherein the Group IVB element-containing material is a titanium-containing material selected from the group consisting of fluorotitanic acid, alkali salts of hexafluorotitanate, amine salts of hexafluorotitanate, and mixtures thereof.

16. The coated metal substrate according to claim 1, wherein the electroconductive pigment is selected from the group consisting of zinc, aluminum, iron, graphite, diiron phosphide, and mixtures thereof.

17. The coated metal substrate according to claim 1, wherein the binder is selected from the group consisting of oligomeric binders, polymeric binders, and mixtures thereof.

18. The coated metal substrate according to claim 1, wherein the binder is selected from the group consisting thermosetting binders, thermoplastic binders, and mixtures thereof.

19. The coated metal substrate according to claim 18, wherein the binder comprises a thermosetting binder selected from the group consisting of polyesters, epoxy-containing materials, phenolics, aminoplasts, polyurethanes and mixtures thereof.

20. The coated metal substrate according to claim 19, wherein the binder comprises an epoxy-containing material which is a polyglycidyl ether of bisphenol A.

21. The coated metal substrate according to claim 19, wherein the weldable coating further comprises a crosslinker for crosslinking the thermosetting binder.

22. The coated metal substrate according to claim 18, wherein the binder comprises a thermoplastic binder selected from the group consisting of vinyl polymers, polyesters, polyolefins, polyamides, polyurethanes, acrylic polymers, and mixtures thereof.

23. The coated metal substrate according to claim 1, wherein the weldable coating further comprises a phosphorus-containing material.

24. The coated metal substrate according to claim 1, wherein the weldable coating further comprises an inorganic lubricant.

25. The coated metal substrate according to claim 24, wherein the inorganic lubricant is molydenum disulfide.

26. The coated metal substrate according to claim 1, wherein the coated metal substrate further comprises a metal phosphate coating deposited upon at least a portion of the weldable coating.

27. The coated metal substrate according to claim 1, wherein the coated metal substrate further comprises an electrodeposited coating deposited upon at least a portion of the weldable coating.

28. A weldable, coated metal substrate comprising:

(a) a bare metal substrate;

(b) a pretreatment coating having less than 0.05 weight percent of chromium-containing materials, the pretreatment coating comprising a reaction product of at least one epoxy-functional material and a phosphorus-containing material deposited upon at least a portion of a surface of the metal substrate; and

(c) a weldable coating comprising an electroconductive pigment and a binder deposited upon at least a portion of the pretreatment coating, wherein the epoxy functional material is a polyglycidyl ether of bisphenol A.