Hydrothermal process for producing zirconia sol
AssigneeNalco Chemical Company
InventorStephen A. Matchett
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Abstract
The present invention provides a novel hydrothermal process for producing zirconia sol comprising the following steps: mixing zirconium acetate with diluted glacial acetic acid to form a zirconium acetate/glacial acetic acid solution, wherein the molar ratio of glacial acetic acid to zirconium acetate as zirconia is in the range between about 7-20; and heating the zirconium acetate/glacial acetic acid solution to a temperature of at least 160.degree. C., thereby forming a zirconia sol.
Claims20
A process for producing a zirconia sol having a polydispersity in the range between about 0.03-0.30, an average particle size in the range between about 60-225 nanometers, and wherein said particles are an aggregate of subunits having an average size in the range between about 2-3 nanometers, comprising the following steps:
- mixing zirconium acetate with a diluted solution of glacial acetic acid to form a composition consisting essentially of zirconium acetate/glacial acetic acid solution, wherein the ratio of the molar concentrations o glacial acetic acid to zirconium acetate as zirconia is in the range between about 7-20;
- and
- heating said zirconium acetate/glacial acetic acid solution in a pressure capable container under hydrothermal conditions to a temperature of at least 160.degree. C., thereby forming a zirconia sol.
A process for producing a monodispersed zirconia sol having a polydispersity less than 0.06, an average particle size in the range between about 60-100 nanometers, and wherein said particles are an aggregate of subunits having an average size in the range between about 2-3 nanometers comprising the following steps:
- mixing zirconium acetate, said zirconium acetate being formed from a zirconium salt containing a removable anion, with a diluted solution of glacial acetic acid to form a composition consisting essentially of zirconium acetate/glacial acetic acid solution, wherein the ratio of the molar concentrations of glacial acetic acid to zirconium acetate as zirconia is in the range between about 10-20 and the molar concentration of zirconium acetate based on zirconia is in the range between about 0.20-0.65, and wherein the combination of said ratio of the molar concentrations of glacial acetic acid to zirconium acetate as zirconia and said molar concentration of zirconium acetate based on zirconia falls within the desired boundaries on the response surface as statistically generated for the data in table 4, said desired boundaries comprising said ratio of molar concentrations of glacial acetic acid to zirconium acetate as zirconia in the range between about 10-20 and the molar concentration of zirconium acetate based on zirconia in the range between about 0.20-0.65;
- and
- heating said zirconium acetate/glacial acetic acid solution in a pressure capable container under hydrothermal conditions to a temperature of at least 160.degree. C., thereby forming a monodispersed zirconia sol with a polydispersity less than 0.06 and a particle size in the range between about 60-100 nanometers.
A zirconia sol having a polydispersity in the range between about 0.03-0.30, an average particle size int he range between about 60-225 nanometers, and wherein said particles are an aggregate of subunits having an average size in the range between about 2-3 nanometers, which is formed in accordance with a process comprising the following steps:
- mixing zirconium acetate with a dilute solution of glacial acetic acid to form a composition consisting essentially of zirconium acetate/glacial acetic acid solution, wherein the ratio of the molar concentrations of glacial acetic acid to zirconium acetate as zirconia is in the range between about 7-20 and the molar concentration of zirconium acetate based on zirconia is in the range between about 0.1-0.8;
- and
- heating said zirconium acetate/glacial acetic acid solution in a pressure capable container under hydrothermal conditions to a temperature of at least 160.degree. C., thereby forming a zirconia sol.
A monodispersed zirconia sol having a polydispersity less than 0.06, an average particle size in the range between about 60-100 nanometers, and wherein said particles are an aggregate of subunits having an average size in the range between about 3-3 nanometers comprising the following steps:
- mixing zirconium acetate, said zirconium acetate being formed form a zirconium salt containing a removable anion, with a diluted solution of glacial acetic acid to form a composition consisting essentially of zirconium acetate/glacial acetic acid solution, wherein the ratio of the molar concentrations of glacial acetic acid to zirconium acetate as zirconia is in the range between about 10-20 and the molar concentration of zirconium acetate based on zirconia is in the range between about 0.20-0.65, and wherein the combination of said ratio of the molar concentrations of glacial acetic acid to zirconium acetate as zirconia and said molar concentrations of zirconium acetate based on zirconia falls within the desired boundaries on the response surface as statistically generated from the data in table 4, said desired boundaries comprising said ratio of molar concentrations of glacial acetic acid to zirconium acetate as zirconia in the range between about 10-20 and the molar concentration of zirconium acetate based on zirconia in the range between about 0.20-0.65;
- and
- heating said zirconium acetate/glacial acetic acid solution in a pressure capable container under hydrothermal conditions to a temperature of at least 160.degree. C., thereby forming a monodispersed zirconia sol with polydispersity less than 0.06 and a particle size in the range between about 60-100 nanometers.
Dependencies are inferred from the claim text.