Coating compositions exhibiting corrosion resistance properties, related coated substrates, and methods

• US 20070048540A1
• Filed: 03/20/2006
• Published: 03/01/2007
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Schneider, John, Ragunathan, Kaliappa
• Granted Patent: US 7,745,010 B2
• Time in Patent Office: Days
• US Class Current: 428/500
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/32 Phosphorus-containing compounds
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C08K 3/38 Boron-containing compounds
• CPC Class Codes: C09D 5/084 Inorganic compounds
• CPC Class Codes: C09D 7/48 Stabilisers against degradation by oxygen, light or heat
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: C09D 7/68 Particle size between 100-1000 nm
• CPC Class Codes: Y10S 977/778 within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/779 Possessing nanosized particles, powders, flakes, or clusters other than simple atomic impurity doping
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/258 Alkali metal or alkaline earth metal or compound thereof
• CPC Class Codes: Y10T 428/259 Silicic material
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/31522 Next to metal
• CPC Class Codes: Y10T 428/31529 Next to metal
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

Coating compositions are disclosed that include corrosion resisting particles such that the coating composition can exhibit corrosion resistance properties. Also disclosed are substrates at least partially coated with a coating deposited from such a composition and multi-component composite coatings, wherein at least one coating later is deposited from such a coating composition. Methods and apparatus for making ultrafine solid particles are also disclosed.

Claims

1. A primer and/or pretreatment coating composition comprising:

(a) an adhesion promoting component; and

(b) corrosion resisting particles selected from;

(i) magnesium oxide particles having an average primary particle size of no more than 100 nanometers;

(ii) particles comprising an inorganic oxide network comprising one or more inorganic oxides; and

/or

(iii) chemically modified particles having an average primary particle size of no more than 500 nanometers.

2. The primer and/or pretreatment coating composition of claim 1, wherein the composition is an etch primer.

3. The primer and/or pretreatment coating composition of claim 1, wherein the composition is substantially free of chromium containing material.

4. The primer and/or pretreatment coating composition of claim 1, wherein the magnesium oxide particles have an average particle size of no more than 50 nanometers.

5. The primer and/or pretreatment coating composition of claim 1, wherein the particles comprising an inorganic oxide network comprising one or more inorganic oxides are formed from hydrolysis of metal salts.

6. The primer and/or pretreatment coating composition of claim 1, wherein the particles comprising an inorganic oxide network comprising one or more inorganic oxides comprise cerium, zinc, zirconium and/or manganese.

7. The primer and/or pretreatment coating composition of claim 6, wherein the particles comprising an inorganic oxide network comprising one or more inorganic oxides further comprises silicon.

8. The primer and/or pretreatment coating composition of claim 1, wherein the particles comprising an inorganic oxide network comprising one or more inorganic oxides are ultrafine particles.

9. The primer and/or pretreatment coating composition of claim 1, wherein the chemically modified particles are chemically modified by reaction of the particles with a compound of the formula:

F-L-Z

wherein F is a moiety containing one or more fuinctional groups that will react with the particle surface, Z is a surface-active moiety that decreases the surface tension of the particle, and L is a group that links F and Z.

10. The primer and/or pretreatment coating composition of claim 1, further comprising a film-forming resin.

11. The primer and/or pretreatment coating composition of claim 10, wherein the weight ratio of the chemically modified particles to the film-forming resin in the composition is less than 0.2 and the composition, when deposited onto at least a portion of a metal substrate selected from cold rolled steel, electrogalvanized steel and aluminum and cured, produces a substrate that exhibits corrosion resistance properties at least similar to the corrosion resistance properties the same substrate exhibits when at least partially coated under the same conditions with a conventional chrome-containing corrosion-resistant composition.

12. The primer and/or pretreatment coating composition of claim 10, wherein the film-forming resin comprises a polyvinyl polymer.

13. The primer and/or pretreatment coating composition of claim 1, wherein the adhesion promoting component comprises a free acid and/or a phosphatized epoxy resin.

14. The primer and/or pretreatment coating composition of claim 1, wherein the composition further comprises a phenolic resin and an alkoxysilane.

15. The primer and/or pretreatment coating composition of claim 1, wherein the composition further comprises corrosion resisting particles comprising a clay.

16. A metal substrate at least partially coated with the primer and/or pretreatment coating composition of claim 1.

17. A method for improving the corrosion resistance properties of a primer and/or pretreatment coating composition, comprising including in the composition corrosion resisting particles selected from:

(i) magnesium oxide particles having an average primary particle size of no more than 100 nanometers;

(ii) particles comprising an inorganic oxide network comprising one or more inorganic oxide; and

/or (iii) chemically modified particles having an average primary particle size of no more than 500 nanometers, such that the corrosion resisting particles are present in the composition in an amount sufficient to result in a composition that, when deposited onto at least a portion of one metal substrate selected from cold rolled steel, electrogalvanized steel and aluminum and cured, provides a substrate that exhibits corrosion resistance properties at least similar to the corrosion resistance properties that the same substrate exhibits when at least partially coated under the same conditions with a conventional chrome-containing corrosion-resistant composition.

18. A method for enhancing the corrosion resistance of a metal substrate, comprising coating at least a portion of a bare metal substrate with a primer and/or pretreatment coating composition that comprises:

(a) an adhesion promoting component, and (b) corrosion resisting particles selected from;

(i) magnesium oxide particles having an average primary particle size of no more than 100 nanometers;

(ii) particles comprising an inorganic oxide network comprising one or more inorganic oxide; and

/or (iii) chemically modified particles having an average primary particle size of no more than 500 nanometers.