Patent DE342932C successfully refreshed from Google Patents.
Patent US4005134A successfully refreshed from Google Patents.
US4005134A
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US
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Method for making aromatic bis(ether dicarboxylic acid)
Assignee: General Electric Co
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Filing: 1975-09-11
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Granted: 1977-01-25
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Expires: 1995-09-11
Abstract
Abstract A method is provided for making aromatic bis(ether dicarboxylic acid) useful for making high performance injection moldable polyetherimides. An aromatic bis(ether N-organo phthalimide) is hydrolyzed directly to the corresponding tetra-acid by heating the aromatic bis(ehter N-organo phthalimide) in a closed system in the presence of acetic acid, water, and a mineral acid.
Inventors
- 👤 Ronald L. Markezich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:18
CPC Classifications
C; C07; C07C; C07C65/00; C07C65/21; C07C65/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
158 words
In a method for making an aromatic bis(ether dicarboxylic acid) based on the hydrolysis of an aromatic bis(ether N-organophthalimide), the improvement which comprises heating a mixture of aromatic bis(ether N-organophthalimide, acetic acid, water and mineral acid in a closed system at a temperature in the range between about 80° C to 200° C, where the mineral acid is used in the mixture at a concentration sufficient to provide from 2 to 8 moles of mineral acid per mole of bisimide and there is utilized a proportion by weight of from about 1 part to 20 parts of glacial acetic acid and from about 1 part to 10 parts of water per part of bisimide which is used in the mixture in a proportion of from 10% by weight to 30% by weight, whereby the direct hydrolysis of the aromatic bis(ether N-organophthalimide) is achieved without resort to a base hydrolysis step followed by acidification of the resulting tetraacid salts.
Claim 2
Dependent Claim
158 words
In a method for making an aromatic bis(ether dicarboxylic acid) based on the hydrolysis of an aromatic bis(ether N-organophthalimide), the improvement which comprises heating a mixture of aromatic bis(ether N-organophthalimide, acetic acid, water and mineral acid in a closed system at a temperature in the range between about 80° C to 200° C, where the mineral acid is used in the mixture at a concentration sufficient to provide from 2 to 8 moles of mineral acid per mole of bisimide and there is utilized a proportion by weight of from about 1 part to 20 parts of glacial acetic acid and from about 1 part to 10 parts of water per part of bisimide which is used in the mixture in a proportion of from 10% by weight to 30% by weight, whereby the direct hydrolysis of the aromatic bis(ether N-organophthalimide) is achieved without resort to a base hydrolysis step followed by acidification of the resulting tetraacid salts.
Claim 3
Dependent Claim
17 words
A method in accordance with claim 1, where the aromatic bis(ether N-organophthalimide) is 2,2-bis[4-(3',4'-dicarboxyphenoxy)phenyl] propane, bis(N-methyl imide).
Claim 4
Dependent Claim
14 words
A method in accordance with claim 1, where the mineral acid is hydrochloric acid.
Claim 5
Dependent Claim
14 words
A method in accordance with claim 1, where the mineral acid is sulfuric acid.
Claim 6
Dependent Claim
14 words
A method in accordance with claim 1, where the mineral acid is phosphoric acid.
Claim 7
Dependent Claim
24 words
A method in accordance with claim 1, where the mixture is heated at a temperature within the range of between 120° to 160° C.
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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |