US4683305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Obtaining caprolactam by cleaving oligomers of caprolactam
Assignee: BASF SE
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Filing: 1986-07-08
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Granted: 1987-07-28
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Expires: 2006-07-08
Abstract
Abstract Caprolactam is obtained by cleaving oligomers of caprolactam by a process in which the oligomers, in a liquid or solid state, are introduced into a fluidized alumina bed and cleaved at from 290° to 400° C. in the presence of steam, and, in addition to the amount of inert gas required to fluidize the alumina bed, from 0.1 to 3 times this amount of inert gas is introduced above the fluidized bed.
Inventors
- 👤 Hugo Fuchs
- 👤 Uwe Brand
- 👤 Helmut Buchaeckert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:19
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/02; C07D201/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
70 words
A process for obtaining caprolactam by cleaving oligomers of caprolactam, wherein the oligomers, in a liquid or solid state, are introduced into a fluidized alumina bed and cleaved at from 290° to 400° C. in the presence of steam, and, in addition to the amount of inert gas required to fluidize the alumina bed, from 0.1 to 3 times this amount of inert gas is introduced above the fluidized bed.
Claim 2
Dependent Claim
70 words
A process for obtaining caprolactam by cleaving oligomers of caprolactam, wherein the oligomers, in a liquid or solid state, are introduced into a fluidized alumina bed and cleaved at from 290° to 400° C. in the presence of steam, and, in addition to the amount of inert gas required to fluidize the alumina bed, from 0.1 to 3 times this amount of inert gas is introduced above the fluidized bed.
Claim 3
Dependent Claim
26 words
The process of claim 1, wherein a fluidization velocity of from 10 to 40 cm/sec, based on the free cross-section, is maintained in the fluidized bed.
Claim 4
Dependent Claim
26 words
The process of claim 1, wherein a caprolactam partial pressure of from 50 to 300 mbar is maintained in the gas space above the fluidized bed.
Claim 5
Dependent Claim
16 words
The process of claim 1, wherein the inert gas introduced above the fluidized bed is nitrogen.
References Cited (Backward Citations)
EP0046183A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |