US3856549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for stabilizing polybenzimidazoles
Assignee: Individual
•
Filing: 1973-06-04
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Granted: 1974-12-24
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Expires: 1993-06-04
Abstract
Abstract A method is provided for improving the ultraviolet light stability of polybenzimidazoles whereby the polymers are immersed in a solution of osmium tetroxide and sodium iodate. The polymers that are treated in this manner retain their physical properties to a substantial degree after prolonged exposure to ultraviolet light. Furthermore, crazing or cracking of the polymers is virtually eliminated.
Inventors
- 👤 R Dauksys
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:56
CPC Classifications
C; C08; C08J; C08J7/00; C08J2379/00; C08J2379/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
82 words
A PROCESS FOR STABILIZING A SHAPED ARTICLE OF A POLYBENZIMIDAZOLE AGAINST DEGRADATION BY ULTRAVIOLET LIGHT WHCH COMPRISES IMMERSING THE ARTICLE OF A PERIOD RANGING FROM 5 MINUTES OF 5 HOURS IN A SOLUTION COMPRISING OSMIUM TETROXIDE AND A SOLVENT THEREFOR SELECTED FROM THE GROUP CONSISTING OF ETHYL ETHER, PYRIDINE AND DIOXANE, THE AMOUNT OF OSMIUM TETROXIDE IN SOLUTION RANGING FROM ABOUT 0.05 TO 1.0 GRAM PER LITER OF SOLUTION AND THE SOLUTION BEING AT A TEMPERATURE RANGING FROM ABOUT 20 TO 100*C.
Claim 2
Dependent Claim
82 words
A PROCESS FOR STABILIZING A SHAPED ARTICLE OF A POLYBENZIMIDAZOLE AGAINST DEGRADATION BY ULTRAVIOLET LIGHT WHCH COMPRISES IMMERSING THE ARTICLE OF A PERIOD RANGING FROM 5 MINUTES OF 5 HOURS IN A SOLUTION COMPRISING OSMIUM TETROXIDE AND A SOLVENT THEREFOR SELECTED FROM THE GROUP CONSISTING OF ETHYL ETHER, PYRIDINE AND DIOXANE, THE AMOUNT OF OSMIUM TETROXIDE IN SOLUTION RANGING FROM ABOUT 0.05 TO 1.0 GRAM PER LITER OF SOLUTION AND THE SOLUTION BEING AT A TEMPERATURE RANGING FROM ABOUT 20 TO 100*C.
Claim 3
Dependent Claim
69 words
The process according to claim 1 in which the article is immersed in a homogeneous colution consisting essentially of 5 to 95 volume percent water and 95 to 5 volume percent of the solvent for the osmium tetroxide, the solution having dissolved therein about 0.05 to 1.0 gram of osmium tetroxide and about 15 to 200 grams of sodium iodate, each amount being based on one liter of solution.
Claim 4
Dependent Claim
31 words
The process according to claim 2 in which the article is immersed in the solution maintained at a temperature of 75* to 80*C for a period of 0.75 to 1.0 hour.
Claim 5
Dependent Claim
26 words
The process according to claim 2 in which the amount of sodium iodate is in the range of 25 to 75 grams per liter of solution.
Claim 6
Dependent Claim
14 words
The process according to claim 2 in which the shaped article is a fabric.
Claim 7
Dependent Claim
14 words
The process according to claim 2 in which the shaped article is a fiber.
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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |