Patent US4052448A successfully refreshed from Google Patents.
US4052448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic acids and process for preparing same
Assignee: Gulf Research and Development Co
•
Filing: 1976-06-16
•
Granted: 1977-10-04
•
Expires: 1996-06-16
Abstract
Abstract A mixture of polycyclic aromatic polycarboxylic acids that is substantially soluble in acetone and substantially soluble in water and a process for preparing the mixture.
Inventors
- 👤 J. Gustav Schulz
- 👤 Edward T. Sabourin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:26
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/08; C07; C07C; C07C201/00; C07C201/06; C07C201/16; C07C51/00; C07C51/16; C07C51/27
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
A process for preparing a mixture of polycyclic aromatic polycarboxylic acids carrying nuclear nitro groups that is soluble in acetone but insoluble in water which comprises subjecting a slurry containing coal to reaction with aqueous nitric acid having a concentration of about 5 to about 90 percent at a temperature of about 15° to about 200° C. for about 0.5 to about 15 hours, mechanically separating the solids in the resulting slurry, extracting the resulting solids with a polar solvent and then separating the polar solvent from the extract to recover the desired carboxylic acid mixture.
Claim 2
Dependent Claim
96 words
A process for preparing a mixture of polycyclic aromatic polycarboxylic acids carrying nuclear nitro groups that is soluble in acetone but insoluble in water which comprises subjecting a slurry containing coal to reaction with aqueous nitric acid having a concentration of about 5 to about 90 percent at a temperature of about 15° to about 200° C. for about 0.5 to about 15 hours, mechanically separating the solids in the resulting slurry, extracting the resulting solids with a polar solvent and then separating the polar solvent from the extract to recover the desired carboxylic acid mixture.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein said polar solvent is acetone.
Claim 4
Dependent Claim
44 words
The process of claim 1 wherein the nitric acid has a concentration of about 10 to about 70 percent and the reaction is carried out at a temperature of about 50° to about 100° C. for about two to about six hours (preferred range).
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the mechanical separation is effected by filtration.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein the acetone separation is effected by subjecting the acetone extract to drying.
Claim 7
Dependent Claim
10 words
The process of claim 1 wherein the coal is lignite.
Claim 8
Dependent Claim
27 words
A mixture of polycyclic aromatic polycarboxylic acids carrying nuclear nitro groups that is soluble in acetone but insoluble in water resulting from the process of claim 1.
References Cited (Backward Citations)
US2726262A
Cited
US3153666A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |