Patent US2673216A successfully refreshed from Google Patents.
US2673216A
Expired / Lapsed
US
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Production of aromatic polycarboxylic acids
Assignee: Directie van de Staatsmijnen in Limburg
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Filing: 1951-03-21
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Granted: 1954-03-23
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Expires: 1971-03-21
Abstract
No abstract record available.
Inventors
- 👤 Martinus L Goedkoop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:53
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/68; C01F7/72; C07; C07C; C07C51/00; C07C51/16; C07C51/27
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
A PROCESS FOR THE PRODUCTION OF AROMATIC POLYCARBOXYLIC ACIDS BY OXIDATION OF CARBONACEOUS MATERIALS WHICH COMPRISES FORMING A SUSPENSION OF SUBDIVIDED SOLID CARBONACEOUS MATERIAL SELECTED FROM THE GROUP CONSISTING OF GRAPHITE, ANTHRACITE, COAL, CHARCOAL, PETROLEUM COKE, COKE, PITCH COKE, RETORT CARBON, PITCH, AND COAL HYDROGENATION RESIDUE IN SULFURIC ACID, ADDING NITRIC ACID THERETO, HEATING THE REACTION MASS TO A TEMPERATURE BETWEEN 130* AND 230* C., CONTINUING ADDITION OF NITRIC ACID TO SAID SUSPENSION UNITL A SUBSTANTIAL AMOUNT OF SAID CARBONACEOUS MATERIAL IS OXIDIZED, AND THEN SEPARATING THE RESULTING SOLUTION OF POLYCARBOXYLIC ACIDS FROM UNDISSOLVED RESIDUE.
Claim 2
Dependent Claim
95 words
A PROCESS FOR THE PRODUCTION OF AROMATIC POLYCARBOXYLIC ACIDS BY OXIDATION OF CARBONACEOUS MATERIALS WHICH COMPRISES FORMING A SUSPENSION OF SUBDIVIDED SOLID CARBONACEOUS MATERIAL SELECTED FROM THE GROUP CONSISTING OF GRAPHITE, ANTHRACITE, COAL, CHARCOAL, PETROLEUM COKE, COKE, PITCH COKE, RETORT CARBON, PITCH, AND COAL HYDROGENATION RESIDUE IN SULFURIC ACID, ADDING NITRIC ACID THERETO, HEATING THE REACTION MASS TO A TEMPERATURE BETWEEN 130* AND 230* C., CONTINUING ADDITION OF NITRIC ACID TO SAID SUSPENSION UNITL A SUBSTANTIAL AMOUNT OF SAID CARBONACEOUS MATERIAL IS OXIDIZED, AND THEN SEPARATING THE RESULTING SOLUTION OF POLYCARBOXYLIC ACIDS FROM UNDISSOLVED RESIDUE.
References Cited (Backward Citations)
FR879182A
Cited
GB190724662A
Cited
US1356137A
Cited
DE441432C
Cited
US2176348A
Cited
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Cited
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Cited
US2555410A
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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) | 1957-03-22 | 1957-09-21 | 1958-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-03-22 | 1961-09-21 | 1962-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-03-22 | 1965-09-21 | 1966-03-23 | $7700.00 | Window Closed / Lapsed |