US2572575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of terephthalic acid
Assignee: Monsanto Chemicals Ltd
•
Filing: 1949-09-23
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Granted: 1951-10-23
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Expires: 1969-09-23
Abstract
No abstract record available.
Inventors
- 👤 Theodore C Shafer
- 👤 Jr Raymond I Longley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:11
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
43 words
A METHOD OF SEPARATING A MIXTURE OF TEREPHTHALIC ACID AND PARA-TOLUIC ACID, WHICH COMPRISES CONTACTING THE MIXTURE ACIDS WITH WATER AT A TEMPERATURE BETWEEN 100* C. AND 200* C., AND FILERING THE RESULTING SLURRY AT A TEMPERATURE BETWEEN 100* C. AND 20* C.
Claim 2
Independent Claim
43 words
A METHOD OF SEPARATING A MIXTURE OF TEREPHTHALIC ACID AND PARA-TOLUIC ACID, WHICH COMPRISES CONTACTING THE MIXTURE ACIDS WITH WATER AT A TEMPERATURE BETWEEN 100* C. AND 200* C., AND FILERING THE RESULTING SLURRY AT A TEMPERATURE BETWEEN 100* C. AND 20* 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) | 1954-10-22 | 1955-04-23 | 1955-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-10-22 | 1959-04-23 | 1959-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-10-22 | 1963-04-23 | 1963-10-23 | $7700.00 | Window Closed / Lapsed |