US3839435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing fiber grade terephthalic acid
Assignee: Kuraray Yuka Co Ltd
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Filing: 1972-01-14
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Granted: 1974-10-01
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Expires: 1992-01-14
Abstract
Abstract 1. IN A PROCESS FOR PRODUCING FIBER GRADE TEREPHTHALIC ACID BY OXIDIZING IN A REACTION VESSEL P-XYLENE IN A LIQUID STATE WITH MOLECULAR OXYGEN OR A MOLECULAR OXYGEN-CONTAINING GAS IN THE PRESENCE OF A LOWER ALIPHATIC CARBOXYLIC ACID TYPE SOLVENT AND A HEAVY METAL CONTANING OXIDIZING CATALYST, THE IMPROVEMENT WHICH COMPRISES CONDUCTING SAID LIQUID-PHASE OXIDATION REACTION IN A VERTICALLY-ELONGATED REACTION VESSEL WHILE SUPLYING CONTINUOUSLY P-XYLENE INTO THE REACTION SYSTEM THROUGH AT LEAST THREE INLETS FOR PXYLENE DISTRIBUTED AT DIFFERING HEIGHTS IN THE VERTICAL DIRECTION OF THE REACTION VESSEL AND STIRRING THE REACTANTS.
Inventors
- 👤 M Shigeyasu
- 👤 K Kuihara
- 👤 M Kuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:25
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/18; C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/255; C07C51/265; B01J2219/00; B01J2219/00049; B01J2219/00164; B01J2219/00166; B01J2219/00189; B01J2219/00761; B01J2219/00763; B01J2219/00765; B01J2219/00768; B01J2219/18; B01J2219/185
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
IN A PROCESS FOR PRODUCING FIBER GRADE TEREPHTHALIC ACID BY OXIDIZING IN A REACTION VESSEL P-XYLENE IN A LIQUID STATE WITH MOLECULAR OXYGEN OR A MOLECULAR OXYGEN-CONTAINING GAS IN THE PRESENCE OF A LOWER ALIPHATIC CARBOXYLIC ACID TYPE SOLVENT AND A HEAVY METAL CONTANING OXIDIZING CATALYST, THE IMPROVEMENT WHICH COMPRISES CONDUCTING SAID LIQUID-PHASE OXIDATION REACTION IN A VERTICALLY-ELONGATED REACTION VESSEL WHILE SUPLYING CONTINUOUSLY P-XYLENE INTO THE REACTION SYSTEM THROUGH AT LEAST THREE INLETS FOR PXYLENE DISTRIBUTED AT DIFFERING HEIGHTS IN THE VERTICAL DIRECTION OF THE REACTION VESSEL AND STIRRING THE REACTANTS.
Claim 2
Dependent Claim
91 words
IN A PROCESS FOR PRODUCING FIBER GRADE TEREPHTHALIC ACID BY OXIDIZING IN A REACTION VESSEL P-XYLENE IN A LIQUID STATE WITH MOLECULAR OXYGEN OR A MOLECULAR OXYGEN-CONTAINING GAS IN THE PRESENCE OF A LOWER ALIPHATIC CARBOXYLIC ACID TYPE SOLVENT AND A HEAVY METAL CONTANING OXIDIZING CATALYST, THE IMPROVEMENT WHICH COMPRISES CONDUCTING SAID LIQUID-PHASE OXIDATION REACTION IN A VERTICALLY-ELONGATED REACTION VESSEL WHILE SUPLYING CONTINUOUSLY P-XYLENE INTO THE REACTION SYSTEM THROUGH AT LEAST THREE INLETS FOR PXYLENE DISTRIBUTED AT DIFFERING HEIGHTS IN THE VERTICAL DIRECTION OF THE REACTION VESSEL AND STIRRING THE REACTANTS.
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) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |