US4268311A
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High strength cordierite ceramic
Assignee: Anchor Hocking LLC
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Filing: 1979-11-01
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Granted: 1981-05-19
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Expires: 1999-11-01
Abstract
Abstract A ceramic body having the oxide composition, SiO 2 : 33-46 wt. % Al 2 O 3 : 37-57 wt. % MgO: 5.5-15 wt. % ZnO: 0.4-1.7 wt. % Na 2 O+K 2 O: 1.0-3.0 wt. % ZrO 2 : 0-5 wt. % The sum of these oxides (including ZrO 2 , if present) should preferably be at least 97% of the total. The remainder of the composition may comprise those ingredients such as CaO, Fe 2 O 3 and/or TiO 2 , which are normally present in conventional ceramic batch raw materials. Essentially no Li 2 O should be present. The fired body, in which cordierite is the perdominant crystal phase, has a modulus of rupture greater than 10,000 psi and often higher than 14,000 psi, and is suitable for freezer-to-oven utensils and for dinnerware. It is glazable with a wide range of glazes including non-Li 2 O containing glazes. The composition from which the ceramic is made has a firing tolerance which is unusually wide for a cordierite ceramic.
Inventors
- 👤 Dennis M. VerDow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:26
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
134 words
A high strength ceramic body containing cordierite as the predominant crystal phase, said body having an oxide analysis comprising: SiO 2 : 33-46 wt.% Al 2 O 3 : 37-57 wt.% MgO: 5.5-15 wt.% ZnO: 0.4-1.7 wt.% Na 2 O+K 2 O: 1.0-3.0 wt.% ZrO 2 : 0-5 wt.% said oxides totalling at least 97% of the total, said body being essentially free of Li 2 O, said body having a modulus of rupture greater than 10,000 psi and being suitable for glazing with a non-Li 2 O containing glaze; the cordierite crystals developing as the predominant crystal phase in said body in a single firing, and the modulus of rupture being substantially higher and the percent absorption substantially lower than that of a ceramic body without ZnO and otherwise of the same composition.
Claim 2
Dependent Claim
134 words
A high strength ceramic body containing cordierite as the predominant crystal phase, said body having an oxide analysis comprising: SiO 2 : 33-46 wt.% Al 2 O 3 : 37-57 wt.% MgO: 5.5-15 wt.% ZnO: 0.4-1.7 wt.% Na 2 O+K 2 O: 1.0-3.0 wt.% ZrO 2 : 0-5 wt.% said oxides totalling at least 97% of the total, said body being essentially free of Li 2 O, said body having a modulus of rupture greater than 10,000 psi and being suitable for glazing with a non-Li 2 O containing glaze; the cordierite crystals developing as the predominant crystal phase in said body in a single firing, and the modulus of rupture being substantially higher and the percent absorption substantially lower than that of a ceramic body without ZnO and otherwise of the same composition.
Claim 3
Dependent Claim
64 words
The ceramic body of claim 1, having the oxide composition SiO 2 : 39-40 wt.% Al 2 O 3 : 45-46 wt.% MgO: 11-12 wt.% ZnO: 0.7-1.0 wt.% Na 2 O: 1.0-1.4 wt.% K 2 O: 0.4-0.6 wt.% CaO: 0.2-0.4 wt.% Fe 2 O 3 : 0-0.5 wt.% TiO 2 : 0-0.5 wt.%, said body having a modulus of rupture greater than 14,000 psi.
Claim 4
Dependent Claim
53 words
The ceramic body of claim 1 having the oxide composition SiO 2 : 39.3 wt.% Al 2 O 3 : 45.8 wt.% MgO: 11.3 wt.% ZnO: 0.8 wt.% Na 2 O: 1.3 wt.% K 2 O: 0.4 wt.% CaO: 0.2 wt.% Fe 2 O 3 : 0.4 wt.% TiO 2 : 0.3 wt.%.
Claim 5
Dependent Claim
25 words
The body of claim 1 wherein the sum of said SiO 2 , Al 2 O 3 , and MgO is 95-97.5% of said body.
Claim 6
Dependent Claim
19 words
The body of claim 1 having a cordierite crystal containing glaze thereon which does not contain Li 2 O.
Claim 7
Dependent Claim
114 words
A one-fire process for making a high strength ceramic body, comprising, preparing a batch consisting essentially of SiO 2 : 33-46 wt.% Al 2 O 3 : 37-57 wt.% MgO: 5.5-15 wt.% ZnO: 0.4-1.7 wt.% Na 2 O+K 2 O: 1.0-3.0 wt.% ZrO 2 : 0-5 wt.% providing the said oxides in sufficient amounts that they total at least 97% of the total, said batch being essentially free of Li 2 O, making a slip from said batch and forming an article of desired shape from the slip, firing the article so formed, the article so fired having a modulus of rupture greater than 10,000 psi and containing cordierite as the predominant crystal phase.
Claim 8
Dependent Claim
114 words
A one-fire process for making a high strength ceramic body, comprising, preparing a batch consisting essentially of SiO 2 : 33-46 wt.% Al 2 O 3 : 37-57 wt.% MgO: 5.5-15 wt.% ZnO: 0.4-1.7 wt.% Na 2 O+K 2 O: 1.0-3.0 wt.% ZrO 2 : 0-5 wt.% providing the said oxides in sufficient amounts that they total at least 97% of the total, said batch being essentially free of Li 2 O, making a slip from said batch and forming an article of desired shape from the slip, firing the article so formed, the article so fired having a modulus of rupture greater than 10,000 psi and containing cordierite as the predominant crystal phase.
Claim 9
Dependent Claim
57 words
The process of claim 6 wherein the batch is prepared to consist essentially of SiO 2 : 39-40 wt.% Al 2 O 3 : 45-46 wt.% MgO: 11-12 wt.% ZnO: 0.7-1.0 wt.% Na 2 O: 1.0-1.4 wt.% K 2 O: 0.4-0.6 wt.% CaO: 0.2-0.4 wt.% Fe 2 O 3 : 0-0.5 wt.% TiO 2 : 0-0.5 wt.%.
Claim 10
Dependent Claim
57 words
The process of claim 6 wherein the batch is prepared to consist essentially of SiO 2 : 39.3 wt.% Al 2 O 3 : 45.8 wt.% MgO: 11.3 wt.% ZnO: 0.8 wt.% Na 2 O: 1.3 wt.% K 2 O: 0.4 wt.% CaO: 0.2 wt.% Fe 2 O 3 : 0.4 wt.% TiO 2 : 0.3 wt.%.
Claim 11
Dependent Claim
16 words
The process of claim 6, wherein said batch is prepared from ingredients which include steatite talc.
Claim 12
Dependent Claim
21 words
The process of claim 6 further wherein a glaze which does not contain Li 2 O is applied to the article.
Claim 13
Dependent Claim
40 words
The process of claim 6 wherein said batch is prepared as a mixture of Nepheline syenite: 5-10 wt.% Steatite talc: 16-42 wt.% Kaolin: 4-32 wt.% Ball clay: 10-19 wt.% Calcined alumina: 25-45 wt.% Zinc oxide: 0.7-1.4 wt.% Bentonite: 0.7-1.5 wt.%.
Claim 14
Dependent Claim
17 words
The process of claim 11 wherein the total clay content is at least 20% of the batch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-18 | 1984-11-17 | 1985-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-18 | 1988-11-17 | 1989-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-18 | 1992-11-17 | 1993-05-19 | $7700.00 | Window Closed / Lapsed |