US3908002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of alpha alumina
Assignee: Shell USA Inc
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Filing: 1972-05-30
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Granted: 1975-09-23
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Expires: 1992-05-30
Abstract
Abstract Inorganic compositions including high surface area Alpha aluminas are produced from the salts of polycarboxylic acids containing aluminum and optionally other metal ions via: (a) the thermal decomposition of the salt in an inert atmosphere to produce a carbonaceous char which is subsequently oxidized to remove the majority of the carbon and leave the inorganic phase, (b) the thermal decomposition of this salt in an inert atmosphere to produce a carbonaceous char which is subsequently heated in an inert atmosphere to effect changes in the inorganic phase present and then is oxidized to remove the majority of the carbon and leave the inorganic phase, or (c) the direct ignition of this salt in an oxygen rich gas mixture.
Inventors
- 👤 Howard V Holler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:24
CPC Classifications
B; B82; B82Y; B82Y30/00; B22; B22F; B22F9/00; B22F9/16; B22F9/30; C; C01; C01B; C01B13/00; C01B13/14; C01F; C01F7/00; C01F7/02; C01F7/30; C01G; C01G3/00; C01G3/02; C01P; C01P2002/00; C01P2002/02; C01P2004/00; C01P2004/60; C01P2004/64; C01P2006/00; C01P2006/12; C01P2006/60; C01P2006/80
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
164 words
THE PROCESS OF PRODUCING ALPHA ALUMINA OF SURFACE AREA AT LEAST ABOUT 40 M2/G WHICH COMPRISES: A. THERMALLY DECARBOXYLATING A POROUS ALUMINUM SALT OF POLYMERIZED UNSATURATED HYDROCARBON CARBOXYLIC ACID IN VACUO AT A TEMPERATURE OF FROM ABOUT 400*C TO ABOUT 600* SAID POROUS ALUMINUM SALT CONSISTING OF AN ALUMINUM-ION-LINKED SALT OF A POLYMRIZED MONOCARBOXYLIC ALKENOIC ACID OF FROM ABOUT 500 TO ABOUT 2,000,000 AVERAGE MOLECULAR WEIGHT AND CONTAINING FROM 3 TO 6 CARBON ATOMS PER MONOMERIC UNIT SELECTED FROM THE GROUP CONSISTING OF ACRYLIC ACID METHACRYLIC ACID CROTONIC ACID MALEIC ACID SORBIC ACID AND ETHACRYLIC ACID, B. HEATING THE RESULTING DECARBOXYLATION PRODUCT IN AN INERT DRY ATMOSPHERE TO A TEMPERATURE ABOVE ABOUT 1000*C THEREBY CONVERTING THE DECARBOXYLATION PRODUCT TO ALPHA ALUMINA OF SAID SURFACE AREA AND FINALLY C. REMOVING RESIDUAL CARBON FROM THE ALPHA ALUMINA PRODUCT BY CONVERSION OF THE CARBON TO A GASEOUS CARBON COMPOUND BY HEATING SAID PRODUCT IN AN OXYGEN CONTAINING ATMOSPHERE AT A TEMPERATURE NOT SUBSTANTIALLY GREATER THAN ABOUT 9000*C.
Claim 2
Dependent Claim
164 words
THE PROCESS OF PRODUCING ALPHA ALUMINA OF SURFACE AREA AT LEAST ABOUT 40 M2/G WHICH COMPRISES: A. THERMALLY DECARBOXYLATING A POROUS ALUMINUM SALT OF POLYMERIZED UNSATURATED HYDROCARBON CARBOXYLIC ACID IN VACUO AT A TEMPERATURE OF FROM ABOUT 400*C TO ABOUT 600* SAID POROUS ALUMINUM SALT CONSISTING OF AN ALUMINUM-ION-LINKED SALT OF A POLYMRIZED MONOCARBOXYLIC ALKENOIC ACID OF FROM ABOUT 500 TO ABOUT 2,000,000 AVERAGE MOLECULAR WEIGHT AND CONTAINING FROM 3 TO 6 CARBON ATOMS PER MONOMERIC UNIT SELECTED FROM THE GROUP CONSISTING OF ACRYLIC ACID METHACRYLIC ACID CROTONIC ACID MALEIC ACID SORBIC ACID AND ETHACRYLIC ACID, B. HEATING THE RESULTING DECARBOXYLATION PRODUCT IN AN INERT DRY ATMOSPHERE TO A TEMPERATURE ABOVE ABOUT 1000*C THEREBY CONVERTING THE DECARBOXYLATION PRODUCT TO ALPHA ALUMINA OF SAID SURFACE AREA AND FINALLY C. REMOVING RESIDUAL CARBON FROM THE ALPHA ALUMINA PRODUCT BY CONVERSION OF THE CARBON TO A GASEOUS CARBON COMPOUND BY HEATING SAID PRODUCT IN AN OXYGEN CONTAINING ATMOSPHERE AT A TEMPERATURE NOT SUBSTANTIALLY GREATER THAN ABOUT 9000*C.
Claim 3
Dependent Claim
20 words
The process in accord with claim 1 wherein the temperature in step (b) is from about 1000*C to about 1400*C.
Claim 4
Dependent Claim
36 words
The process in accord with claim 2 wherein carbon is converted to a gaseous carbon compound in step (c) by contacting the residual carbon with oxygen at a temperature of from about 400*C to about 900*C.
Claim 5
Dependent Claim
59 words
The process in accord with claim 1 wherein the porous aluminum salt of polymerized hydrocarbon carboxylic acid is an aluminum-ion-linked salt of polyacrylic acid, having from about 2,000 to about 500,000 average molecular weight, the temperature in step (b) is from about 1050*C to about 1350*c, and the temperature in step (c) is from about 500*C to about 800*C.
References Cited (Backward Citations)
US2595415A
Cited
US2697066A
Cited
US3108888A
Cited
US3180741A
Cited
US3417028A
Cited
US3352635A
Cited
US3758418A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |