US3948941A
Expired / Lapsed
US
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Preparation of imides using CN- catalysts
Assignee: ExxonMobil Technology and Engineering Co
•
Filing: 1973-10-26
•
Granted: 1976-04-06
•
Expires: 1993-10-26
Abstract
Abstract An improved process for preparing imides comprises reacting acid anhydrides with organic isocyanate groups in the presence of cyanide ion as a catalyst.
Inventors
- 👤 Tad L. Patton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:02
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/44; C07D207/444; C07D207/448; C07D209/00; C07D209/02; C07D209/44; C07D209/48; C07D487/00; C07D487/02; C07D487/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
27 words
In the process of preparing imides by the reaction of carboxylic anhydrides with organic isocyanates, the improvement which comprises: utilizing a CN - ion as the catalyst.
Claim 2
Dependent Claim
27 words
In the process of preparing imides by the reaction of carboxylic anhydrides with organic isocyanates, the improvement which comprises: utilizing a CN - ion as the catalyst.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein said catalyst is derived from sodium cyanide.
Claim 4
Dependent Claim
12 words
A method according to claim 1 wherein said anhydride is a dianhydride.
Claim 5
Dependent Claim
13 words
A method according to claim 1 wherein said anhydride is a mono anhydride.
Claim 6
Dependent Claim
12 words
A method according to claim 1 wherein said isocyanate is a diisocyanate.
Claim 7
Dependent Claim
12 words
A method according to claim 1 wherein said isocyanate is a monoisocyanate.
Claim 8
Dependent Claim
18 words
A method according to claim 1 wherein said isocyanate is a diisocyanate and said anhydride is a dianhydride.
Claim 9
Dependent Claim
12 words
A method according to claim 1 wherein said anhydride is a trianhydride.
Claim 10
Dependent Claim
19 words
A method according to claim 1 wherein said isocyanate is a polyisocyanate containing from 2 to 6 isocyanate groups.
Claim 11
Dependent Claim
12 words
A method according to claim 1 wherein said anhydride is maleic anhydride.
Claim 12
Dependent Claim
29 words
A method according to claim 1 wherein said isocyanate is a diisocyanate and each isocyanate group reacts with one maleic anhydride group to result in the formation of bis-maleimides.
Claim 13
Dependent Claim
37 words
A method according to claim 1 wherein said anhydride is a benzophenone tetracarboxylic acid dianhydride and said isocyanate is selected from the group consisting of toluene diisocyanate, a diphenyl methane diisocyanate or a combination of the two.
Claim 14
Dependent Claim
34 words
A method according to claim 1 wherein said anhydride is a pyromellitic dianhydride and said isocyanate is selected from the group consisting of toluene diisocyanate diphenyl methane diisocyanate or a combination of the two.
Claim 15
Dependent Claim
14 words
A method according to claim 5 wherein said isocyanate is a diphenyl ether diisocyanate.
Claim 16
Dependent Claim
12 words
A method according to claim 4 wherein said anhydride is tetrabromophthalic anhydride.
Claim 17
Dependent Claim
19 words
A method according to claim 6 wherein said anhydride is tetrabromophthalic anhydride and the said isocyanate is chlorophenyl isocyanate.
Claim 18
Dependent Claim
13 words
A method according to claim 4 wherein the said anhydride is tetrachlorophthalic anhydride.
Claim 19
Dependent Claim
19 words
A method according to claim 5 wherein said anhydride is tetrachloro phthalic anhydride and the diisocyanate is diphenylmethane diisocyanate.
Claim 20
Dependent Claim
18 words
A method according to claim 7 wherein the diisocyanate is hexamethylene diisocyanate and the dianhydride is pyromellitic dianhydride.
Claim 21
Dependent Claim
18 words
A method according to claim 7 wherein the diisocyanate is hexamethylene diisocyanate and the dianhydride is benzophenonetetracarboxylic dianhydride.
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) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |