US2828335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrogenation of phthalic acid salts
Assignee: California Research LLC
•
Filing: 1955-11-22
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Granted: 1958-03-25
•
Expires: 1975-11-22
Abstract
No abstract record available.
Inventors
- 👤 Louis L Ferstandig
- 👤 William A Pryor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:03
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/347; C07C51/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
57 words
A PROCESS FOR THE PREPARATION OF HEXAHYDROPHTHALIC ACID SALTS, WHICH COMPRISES SUBJECTING A DISPERSION OF PHTHALIC ACID SALTS TO CONTACT WITH A GAS CONTAINING ELEMENTAL HYDROGEN IN THE PRESENCE OF A RUTHENIUM CATALYST, SAID PHTHALIC ACID SALTS BEING SELECTED FROM THE GROUP CONSISTING OF AMMONIUM SALTS, ALKALI METAL SALTS AND ALKALINE EARTH METAL SALTS OF PHTHALIC ACID.
Claim 2
Dependent Claim
57 words
A PROCESS FOR THE PREPARATION OF HEXAHYDROPHTHALIC ACID SALTS, WHICH COMPRISES SUBJECTING A DISPERSION OF PHTHALIC ACID SALTS TO CONTACT WITH A GAS CONTAINING ELEMENTAL HYDROGEN IN THE PRESENCE OF A RUTHENIUM CATALYST, SAID PHTHALIC ACID SALTS BEING SELECTED FROM THE GROUP CONSISTING OF AMMONIUM SALTS, ALKALI METAL SALTS AND ALKALINE EARTH METAL SALTS OF PHTHALIC ACID.
References Cited (Backward Citations)
US1877991A
Cited
US2675390A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-24 | 1961-09-23 | 1962-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-24 | 1965-09-23 | 1966-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-24 | 1969-09-23 | 1970-03-25 | $7700.00 | Window Closed / Lapsed |