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US4314940A
Expired / Lapsed
US
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Method for the purification of raw caprolactam
Assignee: SNIA Viscosa SpA
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Filing: 1980-04-21
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Granted: 1982-02-09
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Expires: 2000-04-21
Abstract
Abstract A method for the purification of raw caprolactam containing primary amidesf the formula ##STR1## wherein R is a hydrocarbon radical having 1-14 carbon atoms is described. The raw caprolactam is treated with at least one compound containing at least one hydroxyl group, in an amount of at least 20% by weight with respect to the raw caprolactam, at a temperature equal to or higher than that at which the ammonia, which is a part of the amide of formula I, is liberated. The caprolactam is then separated and isolated from the hydroxyl containing compound by known methods.
Inventors
- 👤 Paolo Senni
- 👤 Nando Toderi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:38
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
A method for the purification of raw caprolactam which contains as impurities one or more primary amides having the formula I ##STR3## wherein R is a hydrocarbon radical having from 1 to 14 carbon atoms, comprising, treating said raw caprolactam with at least one compound Y containing at least one hydroxyl group, said compound being a mono- or polyfunctional aliphatic or aromatic alcohol or phenol, in an amount of at least 20% by weight with respect to the raw caprolactam, at a temperature equal to or higher than that at which said primary amide of Formula I reacts with compound Y to form ammonia, maintaining said temperature for a sufficient time for said reaction to near completion; and separating said caprolactam.
Claim 2
Independent Claim
121 words
A method for the purification of raw caprolactam which contains as impurities one or more primary amides having the formula I ##STR3## wherein R is a hydrocarbon radical having from 1 to 14 carbon atoms, comprising, treating said raw caprolactam with at least one compound Y containing at least one hydroxyl group, said compound being a mono- or polyfunctional aliphatic or aromatic alcohol or phenol, in an amount of at least 20% by weight with respect to the raw caprolactam, at a temperature equal to or higher than that at which said primary amide of Formula I reacts with compound Y to form ammonia, maintaining said temperature for a sufficient time for said reaction to near completion; and separating said caprolactam.
Claim 3
Dependent Claim
22 words
Method according to claim 1, wherein the weight ratio of the compound Y and the raw caprolactam is between 20:1 and 0.2:1.
Claim 4
Dependent Claim
19 words
A method according to claim 2, wherein said weight ratio is maintained between about 7:1 and 2:1 by weight.
Claim 5
Independent Claim
18 words
A method according to any one of claims 1, 2 or 3, wherein compound Y is a phenol.
Claim 6
Dependent Claim
25 words
A method according to claim 4, wherein said phenol has at least an alkyl group containing from 1 to 5 carbon atoms as a substituent.
Claim 7
Dependent Claim
17 words
A method according to claim 5, wherein the phenol contains a branched alkyl group as a substituent.
Claim 8
Dependent Claim
14 words
A method according to claim 6, wherein orthotertiary butylphenol is used as the phenol.
Claim 9
Independent Claim
31 words
A method according to any one of claims, 1, 2, or 3 wherein the raw caprolactam is contacted with the compound Y at a temperature between 100° C. and 350° C.
Claim 10
Dependent Claim
25 words
The method according to claim 1 wherein the weight ratio of the compound Y and the raw caprolactam is between 10:1 and 1:1 by weight.
Claim 11
Dependent Claim
16 words
The method according to claim 8 wherein the temperature is between 220° C. and 320° C.
References Cited (Backward Citations)
US4013640A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-08 | 1985-08-10 | 1986-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-08 | 1989-08-10 | 1990-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-08 | 1993-08-10 | 1994-02-09 | $7700.00 | Window Closed / Lapsed |