US3852272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing lactams
Assignee: Stamicarbon BV
•
Filing: 1972-05-02
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Granted: 1974-12-03
•
Expires: 1992-05-02
Abstract
Abstract A process for recovering lactam from a mixture of lactam and sulphuric acid is disclosed, wherein the mixture of lactam and sulphuric acid, such as that produced in a Beckmann rearrangement is partially neutralized and diluted by the addition of ammonia water. The amount of ammonia added is such that the molar ratio
Inventors
- 👤 Rooij A H De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:12
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
62 words
IN A PROCESS FOR RECOVERING LACTAM FROM A MIXTURE OF LACTAM AND SULPHURIC ACID, SAID PROCESS COMPRISING COUNTERCURRENTLY EXTRACTING LACTAM FROM SAID MIXTURE WITH A WATERIMMISCIBLE ORGANIC LACTAM SOLVENT, THE IMPROVEMENT COMPRISING PARTLY NEUTRALIZING AND DILUTING SAID MIXTURE OF LACTAM AND SULPHURIC ACID BY THE ADDITION OF AMMONIA AND WATER, WHEREIN THE AMOUNT OF AMMONIA ADDED IS SUCH THAT THE MOLAR RATIO
Claim 2
Dependent Claim
62 words
IN A PROCESS FOR RECOVERING LACTAM FROM A MIXTURE OF LACTAM AND SULPHURIC ACID, SAID PROCESS COMPRISING COUNTERCURRENTLY EXTRACTING LACTAM FROM SAID MIXTURE WITH A WATERIMMISCIBLE ORGANIC LACTAM SOLVENT, THE IMPROVEMENT COMPRISING PARTLY NEUTRALIZING AND DILUTING SAID MIXTURE OF LACTAM AND SULPHURIC ACID BY THE ADDITION OF AMMONIA AND WATER, WHEREIN THE AMOUNT OF AMMONIA ADDED IS SUCH THAT THE MOLAR RATIO
Claim 3
Dependent Claim
121 words
Process according to claim 1, wherein the neutralization is conducted in two stages, the first neutralization stage involving the addition of all of the dilution water and one-half to two-thirds of the ammonia, thereafter the solution from the first neutralization stage is incompletely extracted in a first extraction by said solvent to form a solvent phase and a sulphuric acid/ammonium sulphate phase, thereafter the remainder of said ammonia is added in a second neutralization stage to the sulphuric acid/ammonium sulphate phase, and thereafter the lactam in said second neutralization stage solution is extracted in a second extraction with said solvent, the solution of lactam in said solvent produced by the second extraction being used to extract lactam in the first extraction.
Claim 4
Dependent Claim
65 words
Process according to claim 1, wherein the partial neutralization of the mixture of lactam and sulphuric acid is conducted in the presence of said solvent, and the resulting mixture from said partial neutralization is subsequently separated into two phases, one phase comprising said solvent containing at least most of said lactam, and the other phase comprising an aqueous solution of ammonium sulphate and sulphuric acid.
Claim 5
Dependent Claim
19 words
Process according to claim 3, wherein lactam is recovered from said aqueous phase by extraction therefrom with said solvent.
Claim 6
Dependent Claim
10 words
Process according to claim 1, wherein said lactam is caprolactam.
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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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |