Zirconia particles
Assignee3M Innovative Properties Company
InventorsRobert Davidson, Brant Kolb, Danny Anderson, James Higgins, Mark Hendrickson, John Brady
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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.
Claims20
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.
Zirconia particles comprising 0.1 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.
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 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.
A composite material comprising zirconia particles dispersed in an organic matrix, the zirconia particles comprising 0.1 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.
A method of making a composite material, said method comprising:
- forming a zirconia sol 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;
- adding an organic matrix material;
- and
- removing at least a portion of a liquid phase from the zirconia sol.
A method of making a composite material, said method comprising:
- providing 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 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,
- adding an organic matrix material;
- and
- removing at least a portion of the aqueous medium from the zirconia sol.
Dependencies are inferred from the claim text.