Patent US3116240A successfully refreshed from Google Patents.
US3116240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of regenerating citric acid etching solutions by ion exchange
Assignee: Pfizer Inc
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Filing: 1961-04-07
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Granted: 1963-12-31
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Expires: 1981-04-07
Abstract
No abstract record available.
Inventors
- 👤 Thomas A Downey
- 👤 John J Mccallion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:30
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
47 words
A PROCESS WHICH COMPRISES CONTACTING A CITRIC ACID ETCHING SOLUTION CONTAINNG DISSOLVED FERROUS ION, FERRIC CITRATE CHELATE ION AND FERIC ION WITH A CATIONIC ION EXCHANGE RESIN TO REMOVE FERROUS ION AND INCREASE THE RELATIVE PROPORTION OF FERRIC ION AND FERRIC CITRIC CHELATE ION IN THE SOLUTION.
Claim 2
Dependent Claim
47 words
A PROCESS WHICH COMPRISES CONTACTING A CITRIC ACID ETCHING SOLUTION CONTAINNG DISSOLVED FERROUS ION, FERRIC CITRATE CHELATE ION AND FERIC ION WITH A CATIONIC ION EXCHANGE RESIN TO REMOVE FERROUS ION AND INCREASE THE RELATIVE PROPORTION OF FERRIC ION AND FERRIC CITRIC CHELATE ION IN THE SOLUTION.
References Cited (Backward Citations)
US2695875A
Cited
US2726141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-12-30 | 1967-07-01 | 1967-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-12-30 | 1971-07-01 | 1971-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-12-30 | 1975-07-01 | 1975-12-31 | $7700.00 | Window Closed / Lapsed |