US2862790A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sulfamic acid purification
Assignee: EIDP Inc
•
Filing: 1955-12-27
•
Granted: 1958-12-02
•
Expires: 1975-12-27
Abstract
No abstract record available.
Inventors
- 👤 George A Peirce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:09
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/082; C01B21/087; C01B21/093; C01B21/0935; C01B21/096
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
113 words
THE PROCESS OF PURIFYING SULFAMIC ACID COMPRISING DISSOLVING SIFFICIENT IMPURE SULFAMIC ACID CONTAINING A SULFATE IMPURITY IN AN AQUEOUS LIQUOR TO PREPARE A SUBSTANTIALLY SATURATED AQUEOUS SOLUTION OF IMPURE SULFAMIC ACID; ADDING TO SAID AQUEOUS SOLUTION A BASIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF AMMONIA, AMMONIUM HYDROXIDE, AMMONIUM SULFAMATE, ALKALI METAL OXIDES, ALKALIU METAL HYDROXIDES AND ALKALI METAL SULFAMATES, SAID BASIC COMPOUND BEING ADDED IN AN EFFECTIVE AMOUNT AND IN AN AMOUNT INSUFFICIENT TO CAUSE CRYSTALLIZATION OUT OF SAID SOLUTION OF SULFAMATE OR SULFATE OF THE CATION OF SAID BASIC COMPOUND; COOLING THE AQUEOUS SOLUTION TO PRECIPITATE HIGH PURITY CRYSTALLINE SULFAMIC ACID; AND REMOVING THE PRECIPITATED SULFAMIC ACID FROM THE COOLED SOLUTION.
Claim 2
Dependent Claim
113 words
THE PROCESS OF PURIFYING SULFAMIC ACID COMPRISING DISSOLVING SIFFICIENT IMPURE SULFAMIC ACID CONTAINING A SULFATE IMPURITY IN AN AQUEOUS LIQUOR TO PREPARE A SUBSTANTIALLY SATURATED AQUEOUS SOLUTION OF IMPURE SULFAMIC ACID; ADDING TO SAID AQUEOUS SOLUTION A BASIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF AMMONIA, AMMONIUM HYDROXIDE, AMMONIUM SULFAMATE, ALKALI METAL OXIDES, ALKALIU METAL HYDROXIDES AND ALKALI METAL SULFAMATES, SAID BASIC COMPOUND BEING ADDED IN AN EFFECTIVE AMOUNT AND IN AN AMOUNT INSUFFICIENT TO CAUSE CRYSTALLIZATION OUT OF SAID SOLUTION OF SULFAMATE OR SULFATE OF THE CATION OF SAID BASIC COMPOUND; COOLING THE AQUEOUS SOLUTION TO PRECIPITATE HIGH PURITY CRYSTALLINE SULFAMIC ACID; AND REMOVING THE PRECIPITATED SULFAMIC ACID FROM THE COOLED SOLUTION.
References Cited (Backward Citations)
US2487480A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-12-01 | 1962-06-02 | 1962-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-01 | 1966-06-02 | 1966-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-01 | 1970-06-02 | 1970-12-02 | $7700.00 | Window Closed / Lapsed |