Patent US4252718A successfully refreshed from Google Patents.
US4252718A
Expired / Lapsed
US
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Continuous azo coupling process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1979-02-09
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Granted: 1981-02-24
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Expires: 1999-02-09
Abstract
Abstract A process for the preparation of an aqueous slurry of a water-insoluble azo compound which comprises continuously mixing together, in a reaction zone from which the slurry is continuously removed, a first stream containing a diazonium compound resulting from the diazotization of a heterocyclic or weakly basic benzenoid amine in an acid medium, hereinafter referred to as the diazo component, and a second stream containing a compound capable of coupling with the diazo component under the conditions existing in the reaction zone to form a water-insoluble azo compound hereinafter referred to as the coupling component.
Inventors
- 👤 John H. Atherton
- 👤 Ian Hodgkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:23
CPC Classifications
C; C09; C09B; C09B41/00; C09B41/006; C09B41/001; C09B41/005; Y; Y10; Y10S; Y10S534/00; Y10S534/07
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
A process for the preparation of an aqueous slurry of a water-insoluble azo compound which comprises continuously mixing together, in a reaction zone from which the slurry is continuously removed, a first stream containing a diazonium compound resulting from the diazotisation of a heterocyclic or weakly basic benzenoid amine in a medium which contains at least 50%, by weight, of sulphuric acid, hereinafter referred to as the diazo component, and a second stream containing a compound capable of coupling with the diazo component under the conditions existing in the reaction zone to form a water-insoluble azo compound hereinafter referred to as the coupling component.
Claim 2
Dependent Claim
104 words
A process for the preparation of an aqueous slurry of a water-insoluble azo compound which comprises continuously mixing together, in a reaction zone from which the slurry is continuously removed, a first stream containing a diazonium compound resulting from the diazotisation of a heterocyclic or weakly basic benzenoid amine in a medium which contains at least 50%, by weight, of sulphuric acid, hereinafter referred to as the diazo component, and a second stream containing a compound capable of coupling with the diazo component under the conditions existing in the reaction zone to form a water-insoluble azo compound hereinafter referred to as the coupling component.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the acid medium comprises sulphuric acid.
Claim 4
Dependent Claim
23 words
A process according to claim 1 wherein the first stream is diluted with water immediately prior to mixing it with the second stream.
Claim 5
Dependent Claim
33 words
A process according to claim 3 wherein acid concentration in the first stream is reduced to within the range 2% to 15% by weight based on the weight of water and acid therein.
Claim 6
Dependent Claim
31 words
A process according to claim 3 wherein the dilution is effected within a period of from 1 sec. to 1 millisecond before the first stream is mixed with the second stream.
Claim 7
Dependent Claim
13 words
A process according to claim 1 performed in the presence of a surfactant.
Claim 8
Dependent Claim
23 words
A process according to claim 1 wherein the product stream is concentrated by a membrane separation process, after the coupling reaction is complete.
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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) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |