Patent US3135787A successfully refreshed from Google Patents.
US3135787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing pure sodium salts of 5-sulfo-isophthalic acid and 2-sulfoterephthalic acid
Assignee: Chemische Werke Witten GmbH
•
Filing: 1961-10-18
•
Granted: 1964-06-02
•
Expires: 1981-10-18
Abstract
No abstract record available.
Inventors
- 👤 Burichardt Rudolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:18
CPC Classifications
C; C07; C07C; C07C303/00; C07C303/02; C07C303/04; C07C303/06; C07C303/32; C07C309/00; C07C309/01; C07C309/28; C07C309/57; C07C309/58
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
198 words
A PROCESS FOR PRODUCING A DESIRED PURE SODIUM SALT OF A SULFOBENZOL DICARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF THE MONO- AND DI-SODIUM SALTS OF 5-SULFO-ISOPHTHALIC ACID AND 2-SULFOTERPHTHALIC ACID, COMPRISING SULFONATING AN ACID SELECTED FROM THE GROUP CONSISTING OF ISOPHTHALIC ACID AND TEREPHTHALIC ACID WITH FUMING SULFURIC ACID AT A TEMPERATURE BETWEEN APPROXIMATEL 120* AND 210*C. IN THE PRESENCE OF A CATALYST SELECTED FROM THE GROUP CONSISTING OF MERCURY AND HALOGEN-FREE MERCURY COMPOUNDS, SEPARATING THE RESULTING CRUDE SULFOBENZOL DICARBOXYLIC ACID FRO THE SULFONATION MIXTURE, PARTIALLY NEUTRALIZING SAID CRUDE SULFOBENZOL DICARBOXYLIC ACID CONTAINING SULFURIC ACID BY THE ADDITION OF A PREDETERMINED AMOUNT OF A SODIUM COMPOUND SELECTED FROM THE GROUP CONSISTING OF SODIUM HYDROXIDE AND SODIUM CARBONATE IN AQUEOUS SOLUTION TO FORM SODIUM SULFATE AND SAID DESIRED SODIUM SALT, SAID PREDETERMINED AMOUNT OF SAID SODIUM COMPOUND BEING THE AMOUNT REQUIRED FOR THE CONVERSION OF SAID SULFOBENZOL DICARBOXYLIC ACID INTO SAID DESIRED SODIUM SALT, COOLING HTE RESULTING HOT SOLUTION OF SAID NEUTRALIZATION TO A TEMPERATURE BETWEEN 23 AND 33*C. TO PRECIPITATE SAID DESIRED SODIUM SALT OF THE SULFOBENZOL DICARBOXYLIC ACID, AND THEREAFTER SEPARATING SAID DESIRED SODIUM SALTR FROM THE SODIUM SULFATE RESTING IN SOLUTION AT SAID LAST-MENTIONED TEMPERATURE.
Claim 2
Dependent Claim
198 words
A PROCESS FOR PRODUCING A DESIRED PURE SODIUM SALT OF A SULFOBENZOL DICARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF THE MONO- AND DI-SODIUM SALTS OF 5-SULFO-ISOPHTHALIC ACID AND 2-SULFOTERPHTHALIC ACID, COMPRISING SULFONATING AN ACID SELECTED FROM THE GROUP CONSISTING OF ISOPHTHALIC ACID AND TEREPHTHALIC ACID WITH FUMING SULFURIC ACID AT A TEMPERATURE BETWEEN APPROXIMATEL 120* AND 210*C. IN THE PRESENCE OF A CATALYST SELECTED FROM THE GROUP CONSISTING OF MERCURY AND HALOGEN-FREE MERCURY COMPOUNDS, SEPARATING THE RESULTING CRUDE SULFOBENZOL DICARBOXYLIC ACID FRO THE SULFONATION MIXTURE, PARTIALLY NEUTRALIZING SAID CRUDE SULFOBENZOL DICARBOXYLIC ACID CONTAINING SULFURIC ACID BY THE ADDITION OF A PREDETERMINED AMOUNT OF A SODIUM COMPOUND SELECTED FROM THE GROUP CONSISTING OF SODIUM HYDROXIDE AND SODIUM CARBONATE IN AQUEOUS SOLUTION TO FORM SODIUM SULFATE AND SAID DESIRED SODIUM SALT, SAID PREDETERMINED AMOUNT OF SAID SODIUM COMPOUND BEING THE AMOUNT REQUIRED FOR THE CONVERSION OF SAID SULFOBENZOL DICARBOXYLIC ACID INTO SAID DESIRED SODIUM SALT, COOLING HTE RESULTING HOT SOLUTION OF SAID NEUTRALIZATION TO A TEMPERATURE BETWEEN 23 AND 33*C. TO PRECIPITATE SAID DESIRED SODIUM SALT OF THE SULFOBENZOL DICARBOXYLIC ACID, AND THEREAFTER SEPARATING SAID DESIRED SODIUM SALTR FROM THE SODIUM SULFATE RESTING IN SOLUTION AT SAID LAST-MENTIONED TEMPERATURE.
References Cited (Backward Citations)
US1745025A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-06-02 | 1967-12-02 | 1968-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-06-02 | 1971-12-02 | 1972-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-06-02 | 1975-12-02 | 1976-06-02 | $7700.00 | Window Closed / Lapsed |