US4197394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making cyclic carbonates and polymers therefrom
Assignee: General Electric Co
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Filing: 1978-08-21
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Granted: 1980-04-08
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Expires: 1998-08-21
Abstract
Abstract A method is provided for making cyclic carbonates of 2,2-bis(4-hydroxyphenyl)-1,1-dichloroethylene, such as the cyclic trimer, by effecting the polymerization of the aforementioned bis (4-hydroxyphenyl)dichloroethylene to a linear polycarbonate, and then agitating a solution of the resulting polycarbonate in the presence of a tertiary ogranic amine. The cyclic carbonates made by the aforementioned process are useful as flame retardants in polycarbonates.
Inventors
- 👤 John E. Hallgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:41
CPC Classifications
C; C07; C07D; C07D323/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
84 words
A method for making polycarbonate consisting essentially of chemically combined units of the formula, ##STR6## which comprises agitating at a temperature up to 300° C. a mixture comprising a cyclopolycarbonate of the formula, ##STR7## in the presence of an effective amount of a tertiary organic amine and an organic solvent and from about 1 to 10 mol percent, based on the total moles of carbonate units in the mixture of a C.sub.(6-20) aryl carbonate, where n is an integer equal to 3 or 4.
Claim 2
Independent Claim
84 words
A method for making polycarbonate consisting essentially of chemically combined units of the formula, ##STR6## which comprises agitating at a temperature up to 300° C. a mixture comprising a cyclopolycarbonate of the formula, ##STR7## in the presence of an effective amount of a tertiary organic amine and an organic solvent and from about 1 to 10 mol percent, based on the total moles of carbonate units in the mixture of a C.sub.(6-20) aryl carbonate, where n is an integer equal to 3 or 4.
Claim 3
Dependent Claim
7 words
A cyclic polycarbonate having the formula, ##STR8##
Claim 4
Dependent Claim
7 words
A cyclic polycarbonate having the formula, ##STR8##
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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |