US3798264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purification of acrylic acid by extraction and distillation
Assignee: Nippon Shokubai Co Ltd
•
Filing: 1971-12-23
•
Granted: 1974-03-19
•
Expires: 1991-12-23
Abstract
Abstract A PROCESS FOR THE PURIFICATION OF ACRYLIC ACID COMPRISING EXTRACTING AN ACRYLIC ACID AQUEOUS SOLUTION FORMED BY THE GAS PHASE CATALYTIC OXIDATION OF PROPYLENE OR ACROLEIN, WITH AN EXTRACTING SOLVENT IN AN EXTRACTION ZONE, SEPARATING THE EXTRACTING SOLVENT FROM THE EXTRACT IN A DISTILLATION ZONE, AND THEREAFTER DISTILLING OFF A MIXTURE OF ACRYLIC ACID AND ACETIC ACID FROM THE REMAINING PORTION OF THE EXTRACT IN A RECTIFICATION ZONE, THEREBY TO OBTAIN ACRYLIC ACID SUBSTANTIALLY FREE OF OF ACETIC SAID PROCESS BEING CHARACETRIZED IN THAT THE DISTILLATE FROM THE RECTIFICATION ZONE CONTAINING ACRYLIC ACID AND ACETIC ACID IS RECYCLED TO THE EXTRACTION ZONE.
Inventors
- 👤 K Kubota
- 👤 N Shimizu
- 👤 T Ohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:51
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/48
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |