US2996430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthetic ion exchange resin recovery of vitamin b12 values
Assignee: Pfizer Inc
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Filing: 1952-05-20
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Granted: 1961-08-15
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Expires: 1972-05-20
Abstract
No abstract record available.
Inventors
- 👤 Jr Edwin N Lightfoot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:21
CPC Classifications
B; B01; B01J; B01J47/00; B01J47/014
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
89 words
A PROCESS FOR CONCENTRATING VITAMIN B12 VALUES WHICH COMPRISES CONTACTING AN IMPURE, ACIDIC SOLUTION OF SAID VALUES AT A PH OF FROM ABOUT 1.5 TO ABOUT 4.5 WITH A SYNTHETIC ION EXCHANGE RESIN CONSISTING OF ACRYLIC ACID COPOLYMERIZED WITH FROM ABOUT 2 TO ABOUT 16 PERCENT BY WEIGHT OF DIVINYL BENZENE, AND ELUTING THE VITAMIN B12 VALUES FROM SAID RESIN WITH AN AQUEOUS SOLUTION OF AN ALKALINE REAGENT SELECTED FROM THE CLASS CONSISTING OF ALKALI METAL HYDROXIDES, AMMONIUM HYDROXIDE, AND THE AMMONIUM AND ALKALI METAL SALTS OF WEAK ACIDS.
Claim 2
Dependent Claim
89 words
A PROCESS FOR CONCENTRATING VITAMIN B12 VALUES WHICH COMPRISES CONTACTING AN IMPURE, ACIDIC SOLUTION OF SAID VALUES AT A PH OF FROM ABOUT 1.5 TO ABOUT 4.5 WITH A SYNTHETIC ION EXCHANGE RESIN CONSISTING OF ACRYLIC ACID COPOLYMERIZED WITH FROM ABOUT 2 TO ABOUT 16 PERCENT BY WEIGHT OF DIVINYL BENZENE, AND ELUTING THE VITAMIN B12 VALUES FROM SAID RESIN WITH AN AQUEOUS SOLUTION OF AN ALKALINE REAGENT SELECTED FROM THE CLASS CONSISTING OF ALKALI METAL HYDROXIDES, AMMONIUM HYDROXIDE, AND THE AMMONIUM AND ALKALI METAL SALTS OF WEAK ACIDS.
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) | 1964-08-14 | 1965-02-13 | 1965-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-14 | 1969-02-13 | 1969-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-14 | 1973-02-13 | 1973-08-15 | $7700.00 | Window Closed / Lapsed |