Patent US3855178A successfully refreshed from Google Patents.
US3855178A
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Method for making polyetherimides
Assignee: General Electric Co
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Filing: 1973-12-03
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Granted: 1974-12-17
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Expires: 1993-12-03
Abstract
Abstract A method is provided for making polyetherimides having improved heat stability involving the initial production of a polyetherimide by the nitro-displacement of dinitro-bisimide with alkali diphenoxide and the employment with the resulting polyetherimide of an alkali metal phenoxide stabilizer.
Inventors
- 👤 D White
- 👤 F Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:07
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1046; C08G73/1053; C08K; C08K5/00; C08K5/04; C08K5/13
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
38 words
A METHOD FOR STABLIZING POLYETHERIMIDE WHICH COMPRISES HEATING AN ORGANIC SOLVENT SOLUTION OF SAID POLYETHERMIDE CONTAINING AT LEAST 1-10 PERCENT BY WEIGHT BASED ON THE WEIGHT OF SAID POLYETHERIMIDE OF AN ALKALI METAL ORGANIC STABILIZER OF THE FORMULA,
Claim 2
Independent Claim
38 words
A METHOD FOR STABLIZING POLYETHERIMIDE WHICH COMPRISES HEATING AN ORGANIC SOLVENT SOLUTION OF SAID POLYETHERMIDE CONTAINING AT LEAST 1-10 PERCENT BY WEIGHT BASED ON THE WEIGHT OF SAID POLYETHERIMIDE OF AN ALKALI METAL ORGANIC STABILIZER OF THE FORMULA,
Claim 3
Dependent Claim
22 words
A method in accordance with claim 1, which is employed to effect a controlled reduction in the intrinsic viscosity of the polyetherimide.
Claim 4
Dependent Claim
24 words
A method in accordance with claim 1, where the polyetherimide forms no more than 1 percent by weight gel at temperatures up to 315*C.
Claim 5
Dependent Claim
15 words
A method in accordance with claim 1, where the stabilizer is an alkali metal cresoxide.
Claim 6
Dependent Claim
21 words
A method in accordance with claim 1, where polyetherimide is stabilized with about 5 percent by weight of alkali metal phenoxide.
Claim 7
Dependent Claim
30 words
A method in accordance with claim 1, where the polyetherimide is stabilized by heating with alkali metal phenoxide to a temperature of about 60*C for up to about 30 minutes.
Claim 8
Dependent Claim
10 words
A method in accordance with claim 1, where R is
Claim 9
Dependent Claim
10 words
A method in accordance with claim 1, where R1 is
Claim 10
Dependent Claim
10 words
A method in accordance with claim 1, where R1 is
Claim 11
Dependent Claim
15 words
A method in accordance with claim 1, when the alkali metal phenoxide is sodium thiocresoxide.
References Cited (Backward Citations)
US2745882A
Cited
US3803103A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |