US2867609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polypyromellitimides
Assignee: EIDP Inc
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Filing: 1955-06-13
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Granted: 1959-01-06
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Expires: 1975-06-13
Abstract
No abstract record available.
Inventors
- 👤 Edwards Walter Murray
- 👤 Robinson Ivan Maxwell
- 👤 Squire Edward Noonan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:18
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1075; C08G73/1082; C08G73/1003
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
126 words
A PROCESS FOR THE PREPARATION OF HIGH-MOLECULARWEIGHT POLYPYROMELLITIMIDES WHICH COMPRISES HEATING A FINELY DIVIDED POLYPROMELLITIMIDE-FORMING SALT IN THE SOLID STATE WITH REMOVAL OF VOLATILES UNTIL A SOLID-STAGE CONDENSATION PRODUCT HAVING AN INHERENT VISCOSITY OF AT LEAST 0.04 IS OBTAINED, AND THEREAFTER FURTHER HEATING THE RESULTING PRODUCT UNTIL A POLYPYROMELLITIMIDE, HAVING AN INHERENT VISCOSITY OF AT LEAST 0.4, IS OBTAINED, SAID POLYPYROMELLITIMIDE-FORMING SALT CONSISTING ESSENTIALLY OF SUBSTANTIALLY EQUIMOLAR AMOUNTS OF (A) A BASIC COMPONENT SELECTED FROM THE GROUP CONSISTING OF DIFUNCTIONAL DIPRIMARY DIAMINES AND MIXTURES THEREOF AND (B) AN ACIDIC COMPONENT SELECTED FORM THE GROUP CONSISTING OF PYROMELLITIC DIACID DIESTERS IN WHICH THE ESTERIFIED CARBOXYL GROUPS ARE ATTACHED TO NON-ADJACENT CARBON ATOMS, AND MIXTURES THEREOF, SAID INHERENT VISCOSITY BEING MEASURED AT 0.5% CONCENTRATION IN META-CRESOL AT 25*C.
Claim 2
Dependent Claim
126 words
A PROCESS FOR THE PREPARATION OF HIGH-MOLECULARWEIGHT POLYPYROMELLITIMIDES WHICH COMPRISES HEATING A FINELY DIVIDED POLYPROMELLITIMIDE-FORMING SALT IN THE SOLID STATE WITH REMOVAL OF VOLATILES UNTIL A SOLID-STAGE CONDENSATION PRODUCT HAVING AN INHERENT VISCOSITY OF AT LEAST 0.04 IS OBTAINED, AND THEREAFTER FURTHER HEATING THE RESULTING PRODUCT UNTIL A POLYPYROMELLITIMIDE, HAVING AN INHERENT VISCOSITY OF AT LEAST 0.4, IS OBTAINED, SAID POLYPYROMELLITIMIDE-FORMING SALT CONSISTING ESSENTIALLY OF SUBSTANTIALLY EQUIMOLAR AMOUNTS OF (A) A BASIC COMPONENT SELECTED FROM THE GROUP CONSISTING OF DIFUNCTIONAL DIPRIMARY DIAMINES AND MIXTURES THEREOF AND (B) AN ACIDIC COMPONENT SELECTED FORM THE GROUP CONSISTING OF PYROMELLITIC DIACID DIESTERS IN WHICH THE ESTERIFIED CARBOXYL GROUPS ARE ATTACHED TO NON-ADJACENT CARBON ATOMS, AND MIXTURES THEREOF, SAID INHERENT VISCOSITY BEING MEASURED AT 0.5% CONCENTRATION IN META-CRESOL AT 25*C.
References Cited (Backward Citations)
US2172274A
Cited
US2710853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-01-05 | 1962-07-07 | 1963-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-05 | 1966-07-07 | 1967-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-05 | 1970-07-07 | 1971-01-06 | $7700.00 | Window Closed / Lapsed |