Patent US4055532A successfully refreshed from Google Patents.
US4055532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized acetonitrile solvent containing polyacrylonitrile compositions and method of forming same
Assignee: Celanese Corp
•
Filing: 1975-08-12
•
Granted: 1977-10-25
•
Expires: 1995-08-12
Abstract
Abstract A method of forming stabilized polyacrylonitrile compositions which are particularly suited for the spinning of polyacrylonitrile fibers and films and the compositions produced thereby wherein acrylonitrile polymers containing at least 85 percent acrylonitrile are dissolved in a solvent which is acetonitrile or an acetonitrile -- water mixture and which contains as a color stabilizer a compound having the following general formula: X -- S -- Y wherein X is a monovalent organic radical which may be substituted or unsubstituted selected from the group consisting of alkyl, cycloalkyl, aryl, and combinations thereof; Y is either hydrogen or X; and the total number of carbon atoms contained in both X and Y is in the range of from about 4 to about 20. Preferably, the solvent and polymer are purged with nitrogen and the pH of the solvent is adjusted to about 6.0 - 7.0.
Inventors
- 👤 Darrell R. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:41
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/36; C08K5/37
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
117 words
A method of forming stabilized film or fiber forming polyacrylonitrile compositions which comprises the steps of adding to a solvent which consists essentially of acetonitrile from about 0.01 to about 3 weight percent based on the weight of said polyacrylonitrile, of a sulfur-containing stabilizer selected from the group consisting dodecanethiol, mercaptosuccinic acid, benzenethiol, thiodiglycol, dibehenyl thiodipropionate, distearyl thiodipropionate, and diethoxyethyl thiodipropionate; adding polyacrylonitrile which contains at least 85 percent acrylonitrile and up to about 15 weight percent of at least one other ethylenically unsaturated material copolymerized therewith; and heating and mixing the resultant mixture under superatomospheric pressure to a temperature above about 80 degrees centigrade and below the degradation temperature of said polyacrylonitrile to produce a solution.
Claim 2
Independent Claim
117 words
A method of forming stabilized film or fiber forming polyacrylonitrile compositions which comprises the steps of adding to a solvent which consists essentially of acetonitrile from about 0.01 to about 3 weight percent based on the weight of said polyacrylonitrile, of a sulfur-containing stabilizer selected from the group consisting dodecanethiol, mercaptosuccinic acid, benzenethiol, thiodiglycol, dibehenyl thiodipropionate, distearyl thiodipropionate, and diethoxyethyl thiodipropionate; adding polyacrylonitrile which contains at least 85 percent acrylonitrile and up to about 15 weight percent of at least one other ethylenically unsaturated material copolymerized therewith; and heating and mixing the resultant mixture under superatomospheric pressure to a temperature above about 80 degrees centigrade and below the degradation temperature of said polyacrylonitrile to produce a solution.
Claim 3
Independent Claim
62 words
A method of forming stabilized film or fiber forming polyacrylonitrile compositions which comprises the steps of adding to a solvent which consists essentially of acetonitrile from about 0.01 to about 3 weight percent based on the weight of said polyacrylonitrile of a sulfur-containing stabilizer selected from the group consisting of dodecanethiol, mercaptosuccinic acid, benzenethiol, thiodiglycol, dibehenyl thiodipropionate, distearyl thiodipropionate, and diethoxyethyl thiodipropionate.
Claim 4
Independent Claim
62 words
A method of forming stabilized film or fiber forming polyacrylonitrile compositions which comprises the steps of adding to a solvent which consists essentially of acetonitrile from about 0.01 to about 3 weight percent based on the weight of said polyacrylonitrile of a sulfur-containing stabilizer selected from the group consisting of dodecanethiol, mercaptosuccinic acid, benzenethiol, thiodiglycol, dibehenyl thiodipropionate, distearyl thiodipropionate, and diethoxyethyl thiodipropionate.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein said superatmospheric pressure is greater than the vapor pressure of said solvent.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein oxygen is excluded and the pH of the solvent is adjusted to about 6.0 - 7.0.
Claim 7
Dependent Claim
19 words
The method of claim 1 wherein said polyacrylonitrile constitutes from about 30 to about 70 percent of said compositions.
References Cited (Backward Citations)
US2525521A
Cited
US2605256A
Cited
US2982753A
Cited
US3194862A
Cited
US3632466A
Cited
US3632543A
Cited
US3755230A
Cited
US3917553A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |