US3032559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resolution of trimellitic anhydride and benzene dicarboxylic acids
Assignee: Standard Oil Co
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Filing: 1960-03-21
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Granted: 1962-05-01
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Expires: 1980-03-21
Abstract
No abstract record available.
Inventors
- 👤 Arthur G Hirsch
- 👤 James O Knobloch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:15
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/573
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
97 words
A METHOD OF IMPROVING THE PURITY OF TRIMELLITIC ANHYDRIDE CONTAMINATED WITH BENZENE DICARBOXYLIC ACID WHICH METHOD COMPRISES CONTACTING, AT A TEMPERATURE FROM ABOUT 30*C. TO ABOUT 125*C., SAID IMPURE ANHYDRIDE WITH AN AMOUNT OF A LIQUID SOLVENT SUFFICIENT TO DISSOLVE ESSENTIALLY ALL OF THE TRIMELLITIC ANHYDRIDE CONTENT, SEPARATING SOLUTION CONTAINING TRIMELLITIC ANHYDRIDE FROM SOLIDS COMPRISING BENZENE DICARBOXYLIC ACID, AND RECOVERING FROM SAID SOLUTION TRIMELLITIC ANHYDRIDE OF PURITY HIGHER THAN SAID IMPURE ANHYDRIDE, AND WHEREIN SAID SOLVENT IS A NORMALLY LIQUID MEMBER SELECTED FROM THE CLASS CONSISTING OF ALKANONES, DIALKYL ETHERS AND ESTERS OF ALKANOLS WITH ALKANOIC ACIDS.
Claim 2
Independent Claim
97 words
A METHOD OF IMPROVING THE PURITY OF TRIMELLITIC ANHYDRIDE CONTAMINATED WITH BENZENE DICARBOXYLIC ACID WHICH METHOD COMPRISES CONTACTING, AT A TEMPERATURE FROM ABOUT 30*C. TO ABOUT 125*C., SAID IMPURE ANHYDRIDE WITH AN AMOUNT OF A LIQUID SOLVENT SUFFICIENT TO DISSOLVE ESSENTIALLY ALL OF THE TRIMELLITIC ANHYDRIDE CONTENT, SEPARATING SOLUTION CONTAINING TRIMELLITIC ANHYDRIDE FROM SOLIDS COMPRISING BENZENE DICARBOXYLIC ACID, AND RECOVERING FROM SAID SOLUTION TRIMELLITIC ANHYDRIDE OF PURITY HIGHER THAN SAID IMPURE ANHYDRIDE, AND WHEREIN SAID SOLVENT IS A NORMALLY LIQUID MEMBER SELECTED FROM THE CLASS CONSISTING OF ALKANONES, DIALKYL ETHERS AND ESTERS OF ALKANOLS WITH ALKANOIC ACIDS.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-04-30 | 1965-10-30 | 1966-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-04-30 | 1969-10-30 | 1970-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-04-30 | 1973-10-30 | 1974-05-01 | $7700.00 | Window Closed / Lapsed |