US3891707A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrogenation process
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1972-05-22
•
Granted: 1975-06-24
•
Expires: 1992-05-22
Abstract
Abstract Aliphatic dinitriles are hydrogenated to aliphatic diamines, for example adiponitrile or 1,4-dicyano-butene are converted to hexamethylene diamine, by heating with hydrogen in the presence of a reduced cobalt borate catalyst. The catalyst is obtained by heating precipitated cobalt borate in the presence of hydrogen, and is made more active by treating, prior to reduction, with an aqueous solution of an alklai, especially an alkali metal carbonate.
Inventors
- 👤 Dhafir Yusuf Waddan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:43
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/44; C07C209/48; B; B01; B01J; B01J23/00; B01J23/70; B01J23/74; B01J23/75
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
42 words
A PROCESS FOR THE MANUFACTURE OF HEXAMETHYLENE DIAMINE WHICH COMPRISES HYDROGENATING ADIPONITRILE OR 1,4-DICYANOBUTENE BY HEATING WITH HYDROGEN AT A TEMPERATURE OF 50* TO 200*C AT A PRESSURE OF 1 TO 500 ATMOSPHERES IN THE PRESENCE OF A REDUCED COBALT BORATE CATALYST.
Claim 2
Dependent Claim
42 words
A PROCESS FOR THE MANUFACTURE OF HEXAMETHYLENE DIAMINE WHICH COMPRISES HYDROGENATING ADIPONITRILE OR 1,4-DICYANOBUTENE BY HEATING WITH HYDROGEN AT A TEMPERATURE OF 50* TO 200*C AT A PRESSURE OF 1 TO 500 ATMOSPHERES IN THE PRESENCE OF A REDUCED COBALT BORATE CATALYST.
Claim 3
Dependent Claim
18 words
The process of claim 1 operated in the presence of not more than 10% by weight of ammonia.
Claim 4
Dependent Claim
32 words
The process of claim 1 in which the reduced cobalt borate catalyst has been obtained by reducing precipitated cobalt borate in the presence of hydrogen at a temperature of 200* to 500*C.
Claim 5
Dependent Claim
23 words
The process of claim 3 in which the precipitated cobalt borate is treated prior to reduction with an aqueous solution of an alkali.
Claim 6
Dependent Claim
25 words
The process of claim 4 in which the precipitated cobalt borate is washed prior to reduction with an aqueous solution of an alkali metal carbonate.
Claim 7
Dependent Claim
16 words
The process of claim 1 in which the reduced cobalt borate catalyst is in pelleted form.
Claim 8
Dependent Claim
82 words
The process of claim 1 for the manufacture of hexamethylenediamine by heating adiponitrile or 1,4-dicyanobutene with hydrogen at 50* to 200*C and a pressure of 1 to 500 atmospheres in the presence of a reduced cobalt borate catalyst, said catalyst having been obtained by precipitating cobalt borate from aqueous solution, washing with precipitate with an aqueous solution of an alkali metal carbonate, drying and heating in hydrogen at a temperature of 300* to 350*C at a pressure of 1 to 300 atmospheres.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |