US4985379A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized metallic oxides
Assignee: Individual
•
Filing: 1988-12-21
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Granted: 1991-01-15
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Expires: 2008-12-21
Abstract
Abstract Zirconia has been used in the manufacture of ceramics for many years. The desirability of stabilizing the crystal form has been recognized and one or more stabilising agents have been used. The present invention produced a stabilized zirconia carrying a coating of at least one hydrous oxide of yttrium, calcium, magnesium, strontium, barium, or cerium. Preferably also a hydrous oxide of zirconium is also present either a s a separate inner layer or mixed with the other hydrous oxide.
Inventors
- 👤 Terence A. Egerton
- 👤 Edmund J. Lawson
- 👤 Peter W. Frost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:13
CPC Classifications
C; C01; C01G; C01G25/00; C01G25/02; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; C01P; C01P2004/00; C01P2004/60; C01P2004/62; C01P2004/80; C01P2004/82; C01P2004/84; C01P2006/00; C01P2006/10; C01P2006/21; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/252; Y10T428/256; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
170 words
A method of manufacturing a solid ceramic body which comprises a. mixing an aqueous dispersion of zirconia particles, said particles having a diameter of less than or equal to 0.5 microns with (i) a water-soluble hydrolyzable salt of zirconium in an amount of from 0.2 to 5 mole % calculated as ZrO 2 based on moles of zirconia particles and (ii) a water-soluble hydrolyzable salt selected from the group consisting of water-soluble salts of yttrium in an amount of from 0.5 to 7 mole % calculated as Y 2 O 3 based on moles of zirconia particles and water-soluble salts of calcium, magnesium, strontium and cerium in an amount of from 2 to 10 mole % expressed as oxide based on moles of zirconia particles; b. precipitating a hydrous oxide of zirconium and a hydrous oxide of yttrium, calcium, magnesium, strontium or cerium onto the zirconia particles; and c. forming the coated zirconia particles into a shaped body and firing said body of particles to form a solid ceramic body.
Claim 2
Independent Claim
170 words
A method of manufacturing a solid ceramic body which comprises a. mixing an aqueous dispersion of zirconia particles, said particles having a diameter of less than or equal to 0.5 microns with (i) a water-soluble hydrolyzable salt of zirconium in an amount of from 0.2 to 5 mole % calculated as ZrO 2 based on moles of zirconia particles and (ii) a water-soluble hydrolyzable salt selected from the group consisting of water-soluble salts of yttrium in an amount of from 0.5 to 7 mole % calculated as Y 2 O 3 based on moles of zirconia particles and water-soluble salts of calcium, magnesium, strontium and cerium in an amount of from 2 to 10 mole % expressed as oxide based on moles of zirconia particles; b. precipitating a hydrous oxide of zirconium and a hydrous oxide of yttrium, calcium, magnesium, strontium or cerium onto the zirconia particles; and c. forming the coated zirconia particles into a shaped body and firing said body of particles to form a solid ceramic body.
Claim 3
Dependent Claim
34 words
The method according to claim 1, wherein the amount of said water-soluble salt of yttrium is from 2 to 5 mole % calculated as Y 2 O 3 based on moles of zirconia particles.
Claim 4
Dependent Claim
35 words
The method according to claim 1, wherein the amount of said water-soluble salts of calcium, magnesium, strontium, and cerium is from 4 to 8 mole % calculated as oxide based on moles of zirconia particles.
Claim 5
Dependent Claim
18 words
The method according to claim 1, wherein said zirconia particles contain less than 0.03% by weight of silica.
Claim 6
Dependent Claim
28 words
The method according to claim 1 in which the aqueous dispersion of zirconia particles is prepared by mixing the product of the oxidation of zirconium tetrachloride with water.
Claim 7
Independent Claim
171 words
A method of manufacturing a solid ceramic body which comprises a. mixing an aqueous dispersion of zirconia particles, said particles having an diameter of less than or equal to 0.5 microns with (i) a water-soluble hydrolyzable salt of zirconium in an amount of from 0.2 to 5 mole % calculated as ZrO 2 based on moles of zirconia particles and (ii) a water-soluble hydrolyzable salt selected from the group consisting of water-soluble salts of yttrium in an amount of from 5 to 10 mole % calculated as Y 2 O 3 based on moles of zirconia particles and water-soluble salts of calcium, magnesium, strontium, and cerium in an amount of from 8 to 20 mole % expressed as oxide based on moles of zirconia particles; b. precipitating a hydrous oxide of zirconium and a hydrous oxide of yttrium, calcium, mangesium, strontium, or cerium on to the zirconia particles; and c. forming the coated zirconia particles into a shaped body and firing said body of particles to form a solid ceramic body.
Claim 8
Independent Claim
171 words
A method of manufacturing a solid ceramic body which comprises a. mixing an aqueous dispersion of zirconia particles, said particles having an diameter of less than or equal to 0.5 microns with (i) a water-soluble hydrolyzable salt of zirconium in an amount of from 0.2 to 5 mole % calculated as ZrO 2 based on moles of zirconia particles and (ii) a water-soluble hydrolyzable salt selected from the group consisting of water-soluble salts of yttrium in an amount of from 5 to 10 mole % calculated as Y 2 O 3 based on moles of zirconia particles and water-soluble salts of calcium, magnesium, strontium, and cerium in an amount of from 8 to 20 mole % expressed as oxide based on moles of zirconia particles; b. precipitating a hydrous oxide of zirconium and a hydrous oxide of yttrium, calcium, mangesium, strontium, or cerium on to the zirconia particles; and c. forming the coated zirconia particles into a shaped body and firing said body of particles to form a solid ceramic body.
Claim 9
Dependent Claim
34 words
The method according to claim 6, wherein the amount of said water-soluble salt of yttrium is from 6 to 9 mole % calculated as Y 2 O 3 based on moles of zirconia particles.
Claim 10
Dependent Claim
44 words
The method according to claim 6, wherein the amount of said water-soluble salts of calcium, magnesium, strontium, and cerium is water-soluble salts of calcium, magnesium, strontium, and cerium is from 9 to 17 mole % calculated as oxide based on moles of zirconia particles.
Claim 11
Dependent Claim
18 words
The method according to claim 6, wherein said zirconia particles contain less than 0.03% by weight of silica.
Claim 12
Dependent Claim
27 words
The method according to claim 6, wherein the aqueous dispersion of zirconia particles is prepared by mixing the product of the oxidation of zirconium tetrachloride with water.
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