US4810681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing dense cordierite
Assignee: NGK Insulators Ltd
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Filing: 1987-06-24
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Granted: 1989-03-07
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Expires: 2007-06-24
Abstract
Abstract Disclosed herein is a method of manufacturing dense cordierite, which includes steps of molding a powder mainly consisting of cordierite crystals and having an average particle size of not more than 5 μm, firing a resulting molding at a temperature of from 1,350° to 1,430° C., whereby the sintered body having a porosity of not more than 6% and a bulk specific gravity of not less than 2.4 is obtained.
Inventors
- 👤 Issei Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:04
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
88 words
A method of manufacturing a dense cordierite body, comprising: milling a powder comprising at least 80% by weight of cordierite crystals to an average particle size of not more than 5 μm by utilizing a zirconia grinding media; molding said milled powder to form a molded body; and firing the molded body at a temperature of from 1,350° to 1,430° C. to from a sintered body, whereby the sintered body has a porosity of not more than 6% and a bulk specific gravity of not less than 2.4.
Claim 2
Independent Claim
88 words
A method of manufacturing a dense cordierite body, comprising: milling a powder comprising at least 80% by weight of cordierite crystals to an average particle size of not more than 5 μm by utilizing a zirconia grinding media; molding said milled powder to form a molded body; and firing the molded body at a temperature of from 1,350° to 1,430° C. to from a sintered body, whereby the sintered body has a porosity of not more than 6% and a bulk specific gravity of not less than 2.4.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein the average particle size of the powder is from 0.3 to 3 μm.
Claim 4
Dependent Claim
14 words
A method according to claim 1, wherein the porosity is from 0.05 to 5%.
Claim 5
Dependent Claim
16 words
A method according to claim 1, wherein the bulk specific gravity is from 2.4 to 2.8.
Claim 6
Dependent Claim
39 words
A method according to claim 1, wherein an amount of zirconium oxide mixed into the milled powder during the milling step is not greater than 20% by weight relative to the amount of cordierite crystals in the milled powder.
References Cited (Backward Citations)
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Cited
US4280845A
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US4235855A
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US4225354A
Cited
US4367292A
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US4495300A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |