US3904668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing iminodiacetonitrile and alkali metal iminodiacetates
Assignee: WR Grace and Co
•
Filing: 1973-11-15
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Granted: 1975-09-09
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Expires: 1993-11-15
Abstract
Abstract Iminodiacetonitrile is prepared by forming an aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile and passing the mixture through a tubular reactor at about 100*-200*C to form iminodiacetonitrile which is recovered. Alternatively the iminodiacetonitrile exit the tubular reactor is fed into an alkali metal hydroxide solution and hydrolyzed to alkali metal iminodiacetate.
Inventors
- 👤 Roger R Gaudette
- 👤 James E Philbrook
- 👤 Jon C Thunberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:06
CPC Classifications
C; C07; C07C; C07C255/00
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
161 words
A PROCESS FOR PREPARING IMINODIACETONITRILE COMPRISING: A. PREPARING AN AQUEOUS MIXTURE OF HEXAMETHYLENETETRAMINE, HCN, AND GLYCOLONITRILE HAVING A MOLE RATIO OF HEXAMETHYLENETHYLENTETRAMINE TO HCN TO GLYCOLONITRILE OF 1:5,2-6,6:1,8-2,2 BY FEEDING THE HCN INTO AN AQUEOUS MIXTURE OF THE HEXAMETHYLENETETRAMINE AND FORMALDE HYDE IN A MIXING AND REACHING ZONE WHILE MAINTAINING THE TEMPERATURE WITHIN THE MIXING AND REACTING ZONE AT 10*-50*C UNTIL ONE-FOURTH OF THE HCN IS ADDED AND THE ADDING THE REMAINING THREE-FOURTHS OF THE HCN WHILE MAINTAINING THE TEMPERATURE WITHIN THE MIXING AND REACTING ZONE AT 0*-30*C, THE PH OF THE AQUEOUS MIXTURE OF HEXAMETHYLENETETRAMINE, HCN, AND GLYCOLONITRILE IN THE MIXING AND REACTING ZONE BEING 4-10: B. PREPARING AN AQUEOUS SYSTEM CONTAINING THE IMINODIACETONITRILE BY PASSING THE AQUEOUS MIXTURE OF HEXAMETHYLENETETRAMINE, HCN, AND GLYCOLONITRILE THROUGH A TUBULAR REACTION ZONE WHILE MAINTANING THE TEMPERATURE WITHIN THE TUBULAR REACTION ZONE AT 50*-200*C, RESIDENCE TIME IN THE TUBULAR REACTION ZONE BEING 0.1-20 MINUTES, AND C. RECOVERING THE IMINODIACETONITRILE EXIT THE TUBULAR REACTION ZONE.
Claim 2
Dependent Claim
161 words
A PROCESS FOR PREPARING IMINODIACETONITRILE COMPRISING: A. PREPARING AN AQUEOUS MIXTURE OF HEXAMETHYLENETETRAMINE, HCN, AND GLYCOLONITRILE HAVING A MOLE RATIO OF HEXAMETHYLENETHYLENTETRAMINE TO HCN TO GLYCOLONITRILE OF 1:5,2-6,6:1,8-2,2 BY FEEDING THE HCN INTO AN AQUEOUS MIXTURE OF THE HEXAMETHYLENETETRAMINE AND FORMALDE HYDE IN A MIXING AND REACHING ZONE WHILE MAINTAINING THE TEMPERATURE WITHIN THE MIXING AND REACTING ZONE AT 10*-50*C UNTIL ONE-FOURTH OF THE HCN IS ADDED AND THE ADDING THE REMAINING THREE-FOURTHS OF THE HCN WHILE MAINTAINING THE TEMPERATURE WITHIN THE MIXING AND REACTING ZONE AT 0*-30*C, THE PH OF THE AQUEOUS MIXTURE OF HEXAMETHYLENETETRAMINE, HCN, AND GLYCOLONITRILE IN THE MIXING AND REACTING ZONE BEING 4-10: B. PREPARING AN AQUEOUS SYSTEM CONTAINING THE IMINODIACETONITRILE BY PASSING THE AQUEOUS MIXTURE OF HEXAMETHYLENETETRAMINE, HCN, AND GLYCOLONITRILE THROUGH A TUBULAR REACTION ZONE WHILE MAINTANING THE TEMPERATURE WITHIN THE TUBULAR REACTION ZONE AT 50*-200*C, RESIDENCE TIME IN THE TUBULAR REACTION ZONE BEING 0.1-20 MINUTES, AND C. RECOVERING THE IMINODIACETONITRILE EXIT THE TUBULAR REACTION ZONE.
Claim 3
Dependent Claim
27 words
The process of claim 1 in which temperature within the mixing and reacting zone is maintained at 25*-35*C while adding the first one-fourth of the HCN thereto.
Claim 4
Dependent Claim
28 words
The process of claim 1 in which the temperature within the mixing and reacting zone is maintained at 5*-15*C while adding the remaining three-fourths of the HCN thereto.
Claim 5
Dependent Claim
34 words
The process of claim 1 in which the temperature within the tubular reaction zone is maintained at about 110*-140*C while passing the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile through the tubular reaction zone.
Claim 6
Dependent Claim
18 words
The process of claim 1 in which the residence time in the tubular reaction zone is 0.5-5.5 minutes.
Claim 7
Dependent Claim
26 words
The process of claim 1 in which the pH of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in the mixing and reacting zone is 7-9.
Claim 8
Dependent Claim
26 words
The process of claim 1 in which the aqueous system exit the tubular reaction zone is cooled to 0*-40*C to cause the iminodiacetonitrile to separate therefrom.
Claim 9
Dependent Claim
18 words
The process of claim 1 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1:5.7-6.3:1.8-2.2.
Claim 10
Dependent Claim
18 words
The process of claim 1 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1:6.0:2.0.
Claim 11
Dependent Claim
69 words
The process of claim 1 in which the preparation of iminodiacetonitrile is conducted in a continuous manner by preparing a first lot and a second lot of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile, passing the first lot of said mixture through the tubular reaction zone, and then preparing a third lot of said mixture while passing the second lot of said mixture through the tubular reaction zone.
Claim 12
Dependent Claim
138 words
A process for preparing iminodiacetonitrile comprising: a. preparing an aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in a mixing and reacting zone, said aqueous mixture having a mole ratio of hexamethylenetetramine to HCN to glycolonitrile of 1:5.2-6.6:1.8-2.2 by feeding the HCN into an aqueous mixture of the hexamethylenetetramine and formaldehyde in the mixing and reacting zone while maintaining the temperature within said zone at 0*-30*C, the pH of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in the mixing and reacting zone being 4-10; b. preparing an aqueous system containing the iminodiacetonitrile by passing the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile through a tubular reaction zone while maintaining the temperature within the tubular reaction zone at 50*-200*C, residence time in the tubular reacting zone being 0.1-20 minutes; and c. recovering the iminodiacetonitrile exit the tubular reaction zone.
Claim 13
Dependent Claim
138 words
A process for preparing iminodiacetonitrile comprising: a. preparing an aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in a mixing and reacting zone, said aqueous mixture having a mole ratio of hexamethylenetetramine to HCN to glycolonitrile of 1:5.2-6.6:1.8-2.2 by feeding the HCN into an aqueous mixture of the hexamethylenetetramine and formaldehyde in the mixing and reacting zone while maintaining the temperature within said zone at 0*-30*C, the pH of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in the mixing and reacting zone being 4-10; b. preparing an aqueous system containing the iminodiacetonitrile by passing the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile through a tubular reaction zone while maintaining the temperature within the tubular reaction zone at 50*-200*C, residence time in the tubular reacting zone being 0.1-20 minutes; and c. recovering the iminodiacetonitrile exit the tubular reaction zone.
Claim 14
Dependent Claim
17 words
The process of claim 11 in which the temperature within the mixing and reacting zone is 5*-15*C.
Claim 15
Dependent Claim
18 words
The process of claim 11 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1:5.7-6.3:1.8-2.2.
Claim 16
Dependent Claim
16 words
The process of claim 11 in which the temperature within the tubular reaction zone is 110*-140*C.
Claim 17
Dependent Claim
18 words
The process of claim 11 in which the residence time in the tubular reaction zone is 0.5-5 minutes.
Claim 18
Dependent Claim
29 words
The process of claim 11 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1:5.7-6.3:1.8-2.2 and the temperature within the mixing and reacting zone is 5*-15*C.
Claim 19
Dependent Claim
16 words
The process of claim 16 in which the temperature within the tubular reaction zone is 110*-140*C.
Claim 20
Dependent Claim
18 words
The process of claim 17 in which the residence time in the tubular reaction zone is 0.5-5 minutes.
Claim 21
Dependent Claim
18 words
The process of claim 11 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1.0:6.0:2.0.
Claim 22
Dependent Claim
21 words
The process of claim 11 in which the pH of the aqueous mixture in the mixing and reacting zone is 7-9.
Claim 23
Dependent Claim
126 words
A process for preparing iminodiacetonitrile comprising: a. preparing an aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile having a mole ratio of hexamethylenetetramine to HCN to glycolonitrile of 1:5.2-6.6: 1.8-2.2 by feeding the HCN into an aqueous mixture of the hexamethylenetetramine and glycolonitrile in a mixing zone while maintaining the temperature within said zone at 10*-50*C, the pH of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in the mixing zone being 4-10; b. preparing an aqueous system containing the iminodiacetonitrile by passing the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile through a tubular reaction zone while maintaining the temperature within the tubular reaction zone at 50*-200*C, residence time in the tubular reaction zone being 0.1-20 minutes, and (c) recovering the iminodiacetonitrile exit the tubular reaction zone.
Claim 24
Dependent Claim
126 words
A process for preparing iminodiacetonitrile comprising: a. preparing an aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile having a mole ratio of hexamethylenetetramine to HCN to glycolonitrile of 1:5.2-6.6: 1.8-2.2 by feeding the HCN into an aqueous mixture of the hexamethylenetetramine and glycolonitrile in a mixing zone while maintaining the temperature within said zone at 10*-50*C, the pH of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in the mixing zone being 4-10; b. preparing an aqueous system containing the iminodiacetonitrile by passing the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile through a tubular reaction zone while maintaining the temperature within the tubular reaction zone at 50*-200*C, residence time in the tubular reaction zone being 0.1-20 minutes, and (c) recovering the iminodiacetonitrile exit the tubular reaction zone.
Claim 25
Dependent Claim
27 words
The process of claim 21 in which temperature within the mixing and reacting zone is maintained at 25*-35*C while adding the first one-fourth of the HCN thereto.
Claim 26
Dependent Claim
29 words
The process of claim 21 in which the temperature within the mixing and reacting zone is maintained at 5*-15*C while the remaining three-fourths of the HCN is added thereto.
Claim 27
Dependent Claim
34 words
The process of claim 21 in which the temperature within the tubular reaction zone is maintained at about 110*-140*C while passing the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile through the tubular reaction zone.
Claim 28
Dependent Claim
18 words
The process of claim 21 in which the residence time in the tubular reaction zone is 0.5-5.5 minutes.
Claim 29
Dependent Claim
24 words
The process of claim 21 in which the pH of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile in the mixing zone is 7-9.
Claim 30
Dependent Claim
26 words
The process of claim 21 in which the aqueous system exit the tubular reaction zone is cooled to 0*-40*C to cause the iminodiacetonitrile to separate therefrom.
Claim 31
Dependent Claim
18 words
The process of claim 21 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1:5.7-6.3:1.8-2.2.
Claim 32
Dependent Claim
18 words
The process of claim 21 in which the mole ratio of hexamethylenetetramine to HCN to glycolonitrile is 1:6.0:2.0.
Claim 33
Dependent Claim
69 words
The process of claim 21 in which the preparation of iminodiacetonitrile is conducted in a continuous manner by preparing a first lot and a second lot of the aqueous mixture of hexamethylenetetramine, HCN, and glycolonitrile, passing the first lot of said mixture through the tubular reaction zone, and then preparing a third lot of said mixture while passing the second lot of said mixture through the tubular reaction zone.
References Cited (Backward Citations)
US2511487A
Cited
US2794044A
Cited
US3167580A
Cited
US3412137A
Cited
US3463811A
Cited
US3534080A
Cited
US3714223A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |