US2817416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid phthalic anhydride recovery
Assignee: California Research LLC
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Filing: 1954-01-28
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Granted: 1957-12-24
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Expires: 1974-01-28
Abstract
No abstract record available.
Inventors
- 👤 Jr Calvin S Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:37
CPC Classifications
B; B01; B01D; B01D7/00; C; C07; C07C; C07C51/00; C07C51/54; C07C51/573
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
93 words
THE PROCESS OF RECOVERING PHTHALIC ANHYDRIDE FROM A HOT MIXTURE OF NORMALLY GASEOUS COMPONENTS HAVING A LOW CONTENT OF PHTHALIC ANHYDIRDESUCH THAT SOLID PHTHALIC ANHYDRIDE IS CONDENSED FROM IT ON NORMAL COOLING, WHICH COMPRISES INTRODUCING THE HOT MIXTURE INTO CONTACT WITH INITIALLY COOL PARTICULATE SOLID HEAT EXCHANGE MATERIAL, THE PARTICLES OF SAID MATERIAL BEING RELATIVELY IMMOVABLE WITH RESPECT TO THE DIMENSIONAL BOUNDARIES OF SAID MATERIAL, CONTINUING THE CONTACT OF THE MIXTURE AND HEAT EXCHANGE MATERIAL UNTIL THERE IS ESTABLISHED A TEMPERATURE GRADEINT IN SAID MATERIAL HAVING A HIGHER LIMIT AT ABOUT THE TEM-
Claim 2
Dependent Claim
93 words
THE PROCESS OF RECOVERING PHTHALIC ANHYDRIDE FROM A HOT MIXTURE OF NORMALLY GASEOUS COMPONENTS HAVING A LOW CONTENT OF PHTHALIC ANHYDIRDESUCH THAT SOLID PHTHALIC ANHYDRIDE IS CONDENSED FROM IT ON NORMAL COOLING, WHICH COMPRISES INTRODUCING THE HOT MIXTURE INTO CONTACT WITH INITIALLY COOL PARTICULATE SOLID HEAT EXCHANGE MATERIAL, THE PARTICLES OF SAID MATERIAL BEING RELATIVELY IMMOVABLE WITH RESPECT TO THE DIMENSIONAL BOUNDARIES OF SAID MATERIAL, CONTINUING THE CONTACT OF THE MIXTURE AND HEAT EXCHANGE MATERIAL UNTIL THERE IS ESTABLISHED A TEMPERATURE GRADEINT IN SAID MATERIAL HAVING A HIGHER LIMIT AT ABOUT THE TEM-
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) | 1960-12-23 | 1961-06-24 | 1961-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-23 | 1965-06-24 | 1965-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-23 | 1969-06-24 | 1969-12-24 | $7700.00 | Window Closed / Lapsed |