US2766098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of obtaining a chromiumcontaining tanning substance
Assignee: Diamond Shamrock Corp
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Filing: 1952-11-19
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Granted: 1956-10-09
•
Expires: 1972-11-19
Abstract
No abstract record available.
Inventors
- 👤 Tom S Perrin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:20
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
THE METHOD OF OBTAINING A TANNING SUBSTANCE FROM THE WASTE BISULFATE-CONTAINING RESIDUE FROM THE MANUFACTURE OF CHROMIC ACID BY REACTING BICHROMATE CRYSTALS WITH SULFURIC ACID, WHICH METHOD INCLUDES THE STEPS OF SLURRYING SAID SOLID WASTE BISULFATE-CONTAINING RESIDUE WITH AN AQUEOUS SOLVENT FOR SAID BISULFATE, SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF WATER AND A WATER SOLUTION OF ALKALI METAL HEXAVALENT CHROMIUM SALT, SETTLING THE RESULTING SLURRY TO OBTAIN A SUPERNATANT LIQUID AND A SOLID-CONTAINING BOTTOM, DECANTING THE SUPERNATANT LIQUID, DISSOLVING THE SOLID-CONTAINING BOTTOM IN SULFURIC ACID, THE CONCENTRATION AND AMOUNT OF SAID ACID BEING SUFFICIENT TO ADJUST THE ACIDITY OF THE RESULTING SOLUTION TO A PH LESS THAN 1, ADDING TO THE RESULTANT SOLUTION SUFFICIENT REDUCING AGENT TO REDUCE THE HEXAVALENT CHROMIUM REMAINING IN SAID SOLUTION TO THE TRIVALENT STATE, ADDING TO THE SOLUTION SUFFICIENT ALKALI TO PROVIDE A PH SUBSTANTIALLY WITHIN THE RANGE OF 2.5-3.5, AND REMOVING WATER FROM THE LATTER SOLUTION.
Claim 2
Independent Claim
155 words
THE METHOD OF OBTAINING A TANNING SUBSTANCE FROM THE WASTE BISULFATE-CONTAINING RESIDUE FROM THE MANUFACTURE OF CHROMIC ACID BY REACTING BICHROMATE CRYSTALS WITH SULFURIC ACID, WHICH METHOD INCLUDES THE STEPS OF SLURRYING SAID SOLID WASTE BISULFATE-CONTAINING RESIDUE WITH AN AQUEOUS SOLVENT FOR SAID BISULFATE, SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF WATER AND A WATER SOLUTION OF ALKALI METAL HEXAVALENT CHROMIUM SALT, SETTLING THE RESULTING SLURRY TO OBTAIN A SUPERNATANT LIQUID AND A SOLID-CONTAINING BOTTOM, DECANTING THE SUPERNATANT LIQUID, DISSOLVING THE SOLID-CONTAINING BOTTOM IN SULFURIC ACID, THE CONCENTRATION AND AMOUNT OF SAID ACID BEING SUFFICIENT TO ADJUST THE ACIDITY OF THE RESULTING SOLUTION TO A PH LESS THAN 1, ADDING TO THE RESULTANT SOLUTION SUFFICIENT REDUCING AGENT TO REDUCE THE HEXAVALENT CHROMIUM REMAINING IN SAID SOLUTION TO THE TRIVALENT STATE, ADDING TO THE SOLUTION SUFFICIENT ALKALI TO PROVIDE A PH SUBSTANTIALLY WITHIN THE RANGE OF 2.5-3.5, AND REMOVING WATER FROM THE LATTER SOLUTION.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-10-09 | 1960-04-09 | 1960-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-09 | 1964-04-09 | 1964-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-09 | 1968-04-09 | 1968-10-09 | $7700.00 | Window Closed / Lapsed |