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AssigneeAsahi Glass Company, Limited
InventorsYoshihisa Beppu, Kazuo Sunahara
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To provide a process for producing ceria-zirconia solid solution crystal fine particles having high crystallinity, being excellent in uniformity of composition and particle size, having a small particle size and a high specific surface area and being excellent in heat resistance, and such solid solution crystal fine particles. A process comprises a step of obtaining a melt containing, as represented by mol % based on oxides, from 5 to 50% of (ZrO2+CeO2), from 10 to 60% of RO (wherein R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba) and from 25 to 70% of B2O3, a step of quenching the melt to obtain an amorphous material, a step of heating the amorphous material at a temperature of from 550 to 1000° C. to precipitate a ceria-zirconia solid solution crystal in the amorphous material, and a step of separating components other than the ceria-zirconia solid solution crystal from the obtained precipitates to obtain the ceria-zirconia solid solution crystal fine particles, in this order.
A process for producing ceria-zirconia solid solution crystal fine particles, comprising (1) obtaining a melt containing, as represented by mol % based on oxides, from 5 to 50% of (ZrO2+CeO2), from 10 to 60% of RO (wherein R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba) and from 25 to 70% of B2O3 by heating at a temperature of from 1200 to 1600° C., (2) quenching the melt to obtain an amorphous material, (3) heating the amorphous material at a temperature of from 550 to 1000° C. to precipitate ceria-zirconia solid solution crystals in the amorphous material, and (4) separating components other than the ceria-zirconia solid solution crystals from the obtained precipitates to obtain the ceria-zirconia solid solution crystal fine particles, in this order.
Dependencies are inferred from the claim text.