US4187370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization and recovery of 2-pyrrolidone with acid treatment
Assignee: Chevron USA Inc
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Filing: 1977-10-17
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Granted: 1980-02-05
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Expires: 1997-10-17
Abstract
Abstract An alkaline-catalyzed process for preparing poly-2-pyrrolidone characterized by the step of treating the polypyrrolidone reaction product mixture with an acid to prevent polymer agglomeration and prevent base-catalyzed polymer degradation. In another embodiment, unreacted poly-2-pyrrolidone is recovered by washing the acid-treated polymer reaction product mixture with water and the resulting wash water recovered, treated with further acid, and then subjected to a two-stage evaporation process. Poly-2-pyrrolidone is known as nylon 4, and can be shaped into filaments and various molded articles.
Inventors
- 👤 Byron E. Anshus
- 👤 Kiyoshi Katsumoto
- 👤 Ira M. Serkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:40
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/18; C07D207/22; C07D207/24; C07D207/26; C07D207/263; C07D207/267; B; B01; B01D; B01D3/00; B01D3/34; C07D201/00; C07D201/16; C08; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
68 words
A process for the polymerization of pyrrolidone, which comprises polymerizing under substantially anhydrous conditions a mixture containing alkaline catalyst, pyrrolidone, and solvent, to form a substantially anhydrous reaction product mixture consisting essentially of particulate poly-2-pyrrolidone, alkaline catalyst and solvent and, before said poly-2-pyrrolidone can appreciably agglomerate, treating said reaction product mixture with an acid to reduce the pH of the resulting mixture to about from 5 to 8.
Claim 2
Dependent Claim
68 words
A process for the polymerization of pyrrolidone, which comprises polymerizing under substantially anhydrous conditions a mixture containing alkaline catalyst, pyrrolidone, and solvent, to form a substantially anhydrous reaction product mixture consisting essentially of particulate poly-2-pyrrolidone, alkaline catalyst and solvent and, before said poly-2-pyrrolidone can appreciably agglomerate, treating said reaction product mixture with an acid to reduce the pH of the resulting mixture to about from 5 to 8.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said acid is an aqueous acid.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said acid is a strong mineral acid or a strong organic acid.
Claim 5
Dependent Claim
24 words
The process of claim 3 wherein said acid is selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, and mixtures thereof.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein said acid is sulfuric acid.
Claim 7
Dependent Claim
10 words
The process of claim 1 wherein said solvent is pyrrolidone.
Claim 8
Dependent Claim
11 words
The process of claim 6 wherein said acid is sulfuric acid.
Claim 9
Dependent Claim
30 words
The process of claim 1 wherein the treatment of said reaction product mixture with said acid is effected at temperatures in the range of about from 20° to 70° C.
Claim 10
Dependent Claim
35 words
The process of claim 1 wherein said alkaline catalyst is prepared by reacting an excess of pyrrolidone with an alkali metal hydroxide to yield a solution of an alkali metal salt of pyrrolidone in pyrrolidone.
Claim 11
Dependent Claim
23 words
The process for the polymerization of 2-pyrrolidone according to claim 9, wherein said alkali metal hydroxide is an aqueous alkali metal hydroxide solution.
Claim 12
Dependent Claim
27 words
The process for the polymerization of 2-pyrrolidone according to claim 10, wherein said alkali metal hydroxide solution is a potassium hydroxide solution containing 20-60 weight percent KOH.
Claim 13
Dependent Claim
65 words
The process of claim 9, wherein said alkali metal salt of pyrrolidone solution is dehydrated to substantially remove water and is then contacted with carbon dioxide at a temperature of about 60°-95° C. to provide a carbonated alkaline mixture containing about 1-5 mol percent carbon dioxide based on total 2-pyrrolidone and polymerizing the resulting mixture at a temperature in the range of about 40°-60° C.
References Cited (Backward Citations)
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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) | 1983-02-04 | 1983-08-06 | 1984-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-04 | 1987-08-06 | 1988-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-04 | 1991-08-06 | 1992-02-05 | $7700.00 | Window Closed / Lapsed |