Patent US2695215A successfully refreshed from Google Patents.
US2695215A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of chromium oxide
Assignee: C K Williams & Co
•
Filing: 1950-05-16
•
Granted: 1954-11-23
•
Expires: 1970-05-16
Abstract
No abstract record available.
Inventors
- 👤 William A Pollock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:19
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/34; C09C1/346; C01; C01G; C01G37/00; C01G37/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
120 words
THE PROCESS OF PRODUCING CHROMIUM OXIDE PIGMENTS WHICH COMPRISES REACTING SODIUM CHROMATE WITH A SODIUM SULFIDE THEREBY FORMING A REACTION MASS CONTAINING CHROMIUM HYDROXIDE AND THIOSULFATE IN A HIGHLY ALKALINE REACTION MASS, ADDING AN ACID MATERIAL IN A QUANTITY LOWERING THE PH VALUE BELOW 9, MIXING WITH SAID REACTION MASS SODIUM CHROMATE IN A QUANTITY CALCULATED TO REACT WITH AT LEAST 75 PER CENT OF THE SODIUM THIOSULFATE PRESENT, REACTING THE CHROMATE WITH THE THIOSULFATE THEREBY FORMING HYDRATED CHROMIUM OXIDE AND SODIUM SULFITE IN ADMIXTURE WITH THE CHROMIUM HYDROXISE, CALCINING THE RESULTING MIXED PRODUCT AT A TEMPERATURE OF FROM 1650* TO 1950* F., WASHING THE CALCINED PRODUCT TO REMOVE SOLUBLE IMPURITIES AND DRYING AND GRINDING TO PROVIDE CHROMIUM OXIDE PIGMENT.
Claim 2
Dependent Claim
120 words
THE PROCESS OF PRODUCING CHROMIUM OXIDE PIGMENTS WHICH COMPRISES REACTING SODIUM CHROMATE WITH A SODIUM SULFIDE THEREBY FORMING A REACTION MASS CONTAINING CHROMIUM HYDROXIDE AND THIOSULFATE IN A HIGHLY ALKALINE REACTION MASS, ADDING AN ACID MATERIAL IN A QUANTITY LOWERING THE PH VALUE BELOW 9, MIXING WITH SAID REACTION MASS SODIUM CHROMATE IN A QUANTITY CALCULATED TO REACT WITH AT LEAST 75 PER CENT OF THE SODIUM THIOSULFATE PRESENT, REACTING THE CHROMATE WITH THE THIOSULFATE THEREBY FORMING HYDRATED CHROMIUM OXIDE AND SODIUM SULFITE IN ADMIXTURE WITH THE CHROMIUM HYDROXISE, CALCINING THE RESULTING MIXED PRODUCT AT A TEMPERATURE OF FROM 1650* TO 1950* F., WASHING THE CALCINED PRODUCT TO REMOVE SOLUBLE IMPURITIES AND DRYING AND GRINDING TO PROVIDE CHROMIUM OXIDE PIGMENT.
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) | 1957-11-22 | 1958-05-24 | 1958-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-11-22 | 1962-05-24 | 1962-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-11-22 | 1966-05-24 | 1966-11-23 | $7700.00 | Window Closed / Lapsed |