Patent US4166899A successfully refreshed from Google Patents.
US4166899A
Expired / Lapsed
US
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Isolation of aromatic polyester copolymers
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1976-12-03
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Granted: 1979-09-04
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Expires: 1996-12-03
Abstract
Abstract A method for the isolation of aromatic polyesters of a uniform and fine powder which comprises mixing a 1,2-dichloroethane solution containing 8 to 50% by weight of an aromatic polyester copolymer with 0.01 to 1.0 time by volume (based on said solution) of methanol, and isolating the resulting precipitates, said 1,2-dichloroethane solution containing an aromatic polyester copolymer being produced by contacting an aqueous alkaline solution of 2,2-bis(4'-hydroxyphenyl)propane with a 1,2-dichloroethane solution of a mixture of terephthaloyl chloride and isophthaloyl chloride.
Inventors
- 👤 Takashi Maruyama
- 👤 Katsuji Ueno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:05
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/40; C08G63/88; C08G63/89
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
A method for the production of aromatic polyesters of a uniform and fine powder, which comprises: mixing an aqueous alkaline solution of 2,2-bis(4'-hydroxyphenyl) propane with a 1,2-dichloroethane solution of a mixture of terephthaloyl chloride and isophthaloyl chloride with stirring to obtain a mixture containing an aromatic polyester copolymer; subjecting the mixture to liquid-liquid phase separation; washing the thus separated 1,2-dichloroethane solution containing the aromatic polyester copolymer using methanol or a methanol-containing aqueous solution as a washing liquid, said separated 1,2-dichloroethane solution having a water content of less than 50% by weight based on 1,2-dichloroethane, the amount of methanol being in the range of 5 to 95% by weight based on the total amount of said washing liquid and water contained in the separated 1,2-dichloroethane solution before washing; mixing the 1,2-dichloroethane solution thus washed with 0.01 to 1.0 time by volume, based on said solution, of methanol, said 1,2-dichloroethane solution containing 8 to 50% by weight of the aromatic polyester copolymer; and isolating the resulting precipitates.
Claim 2
Independent Claim
165 words
A method for the production of aromatic polyesters of a uniform and fine powder, which comprises: mixing an aqueous alkaline solution of 2,2-bis(4'-hydroxyphenyl) propane with a 1,2-dichloroethane solution of a mixture of terephthaloyl chloride and isophthaloyl chloride with stirring to obtain a mixture containing an aromatic polyester copolymer; subjecting the mixture to liquid-liquid phase separation; washing the thus separated 1,2-dichloroethane solution containing the aromatic polyester copolymer using methanol or a methanol-containing aqueous solution as a washing liquid, said separated 1,2-dichloroethane solution having a water content of less than 50% by weight based on 1,2-dichloroethane, the amount of methanol being in the range of 5 to 95% by weight based on the total amount of said washing liquid and water contained in the separated 1,2-dichloroethane solution before washing; mixing the 1,2-dichloroethane solution thus washed with 0.01 to 1.0 time by volume, based on said solution, of methanol, said 1,2-dichloroethane solution containing 8 to 50% by weight of the aromatic polyester copolymer; and isolating the resulting precipitates.
Claim 3
Dependent Claim
34 words
A method according to claim 1, wherein the amount of said washing liquid is in the range of from 0.05 to 3 times by weight based on 1,2-dichloroethane in said copolymer solution before washing.
Claim 4
Dependent Claim
25 words
A method according to claim 2, wherein the amount of said washing liquid is in the range of from 0.1 to 2 times by weight.
Claim 5
Dependent Claim
25 words
A method according to claim 1, wherein said 1,2-dichloroethane solution after washing has a water content of less than 3% by weight based on 1,2-dichloroethane.
Claim 6
Dependent Claim
15 words
An aromatic polyester copolymer obtained according to the method as set forth in claim 1.
Claim 7
Dependent Claim
22 words
An aromatic polyester copolymer according to claim 5, wherein said aromatic polyester copolymer has a sodium content of less than 100 ppm.
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) | 1982-09-03 | 1983-03-05 | 1983-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-03 | 1987-03-05 | 1987-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-03 | 1991-03-05 | 1991-09-04 | $7700.00 | Window Closed / Lapsed |