Zirconia particles

• US 7,241,437 B2
• Filed: 12/30/2004
• Issued: 07/10/2007
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Kolb, Brant U., Brady, John T., Davidson, Robert S., Hendrickson, Mark J., Higgins, James A., Anderson, Danny B.
• Primary Examiner(s): Vanoy; Timothy C.
• Application Number:
  US11/027,426
• Publication Number:
  US 20060148950A1
• Time in Patent Office: 922 Days
• Field of Search: 423/608, 423/69, 423/85, 423/593.1
• US Class Current: 423/608
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01G 25/02 Oxides
• CPC Class Codes: C01P 2002/70 defined by measured X-ray, neutron or electron diffraction data
• CPC Class Codes: C01P 2002/88 by thermal analysis data, e.g. TGA, DTA, DSC
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C09C 1/00 Treatment of specific inorganic materials other than fibrous fillers tenebrescent materials C09K9/00; luminescent materials C09K11/00; Preparation of carbon black
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• 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 428/31609 Particulate metal or metal compound-containing
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

Zirconia particles, methods of making zirconia particles, composite materials that contain the zirconia particles, methods of making the composite materials, and zirconia sols that contain the zirconia particles are described. The zirconia particles are substantially non-associated and have an average size no greater than 50 nanometers and may contain yttrium. The zirconia particles are prepared by a method that includes two separate hydrothermal treatments.

Claims

1. A method of making zirconia particles, the method comprising:

preparing a first feedstock comprising a zirconium salt;

subjecting the first feedstock to a first hydrothermal treatment to form a zirconium-containing intermediate and a byproduct;

forming a second feedstock by removing at least a portion of the byproduct of the first hydrothermal treatment; and

subjecting the second feedstock to a second hydrothermal treatment to form a zirconia sol comprising zirconia particles.

2. The method of claim 1, wherein the zirconium salt has an anion comprising a carboxylate having no greater than four carbon atoms.

3. The method of claim 1, wherein the zirconium salt has an anion comprising a carboxylate comprising a first carboxylate anion having no greater than four carbon atoms and a second carboxylate anion that is a polyether carboxylate anion, wherein at least 50 mole percent of the carboxylate anions have no greater than four carbon atoms.

4. The method of claim 3, wherein the polyether carboxylate anion is 2-[2-(2-methoxyethoxy)ethoxy]acetate, 2-(2-methoxyethoxy)acetate, or a combination thereof.

5. The method of claim 2, wherein the carboxylate anion is acetate.

6. The method of claim 1, wherein the first feedstock further comprises an yttrium salt.

7. The method of claim 1, wherein preparing the first feedstock comprises preparing a precursor solution comprising a zirconium salt and removing at least a portion of an anion of the zirconium salt in the precursor solution.

8. The method of claim 7, wherein removing comprises heating the precursor solution to volatilize an acid formed from the anion of the zirconium salt.

9. The method of claim 7, wherein removing comprises at least partially drying the precursor solution to form a residue;

and dispersing the residue in water.

10. The method of claim 1, wherein the zirconium-containing intermediate has a percent conversion of 40 to 75 percent.

11. The method of claim 1, wherein forming the second feedstock comprises removing an acidic byproduct formed during the first hydrothermal treatment.

12. The method of claim 11, wherein the acidic byproduct comprises a carboxylic acid having no greater than four carbon atoms.

13. The method of claim 1, wherein removing comprises at least partially drying the zirconium-containing intermediate to form an intermediate residue;

and diluting the intermediate residue with water.

14. The method of claim 1, further comprising removing a liquid phase from the zirconia sol, modifying the surface of the zirconia particles, or a combination thereof.

15. Zirconia particles comprising 1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles, the zirconia particles having an average primary particle size no greater than 30 nanometers, a dispersion index of 1 to 3, a ratio of intensity-average particle size to volume-average particle size no greater than 3.0, and a crystal structure that is at least 70 percent cubic, tetragonal, or a combination thereof.

16. A zirconia sol comprising zirconia particles comprising 1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles, the zirconia particles dispersed in an aqueous medium comprising a carboxylic acid, wherein the carboxylic acid has no greater than four carbon atoms and is substantially free of a polyether carboxylic acid;

and the zirconia particles have an average primary particle size no greater than 30 nanometers, a dispersion index of 1 to 5, a ratio of intensity-average particle size to volume-average particle size no greater than 3.0, and a crystal structure that is at least 50 percent cubic, tetragonal, or a combination thereof.

17. A method of making zirconia particles, the method comprising a first hydrothermal treatment and a separate second hydrothermal treatment, wherein a product of the second hydrothermal treatment prior to any additional treatment comprises a zirconia sol comprising zirconia particles dispersed in an aqueous medium comprising a carboxylic acid, wherein the carboxylic acid has no greater than four carbon atoms and is substantially free of polyether carboxylic acid;

and the zirconia particles have an average particle size no greater than 30 nanometers, a dispersion index of 1 to 5, and a crystal structure that is at least 50 percent cubic, tetragonal, or a combination thereof.

18. The method of making zirconia particles of claim 17, wherein the zirconia particles comprise 0.1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles.