US2569663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for and method of determining chromate concentrations
Assignee: Dearborn Chemical Co
•
Filing: 1947-12-31
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Granted: 1951-10-02
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Expires: 1967-12-31
Abstract
No abstract record available.
Inventors
- 👤 Harry E Frank
- 👤 Melvin A Hanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:55
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; Y; Y10; Y10S; Y10S436/00; Y10S436/904
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
145 words
A METHOD FOR THE DETERMINATION OF CHROMATE CONCENTRATION IN AN ALKALINE CHROMATE SOLUTION OF UNKNOWN CONCENTRATION, WHICH COMPRISES IMPREGNATING A WHITE BIBULOUS SHEET WITH AN AQUEOUS FROM THE GROUP CONSISTING OF CITRIC ACID LITER OF SOLUTION OF A CRYSTALLINE ORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF CITRIC ACID AND TARTARIC ACID AND FROM 3 TO 8 GRAMS PER LITER OF SOLUTION OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF BENZIDINE, HYDROCHLORIC ACID AND ACETIC ACID DERIVATIVES OF BENZIDINE, DRYING SAID IMPREGNATED SHEET AND PLACING A DROP OF SAID ALKALINE CHROMATE SOLUTION ON SAID DRY SHEET, THE CONCENTRATION OF SAID ACID AND OF SAID COMPOUND IN SAID SHEET BEING SUCH THAT UPON CONTACT OF SAID DROP WITH SAID SHEET A COLOR WILL DEVELOP WITHIN THE RANGE FROM BLUE THROUGH GOLDEN TO BROWNISH GOLD DEPENDING UPON THE CONCENTRATION OF THE CHROMATE IN SAID CHROMATE SOLUTION
Claim 2
Independent Claim
145 words
A METHOD FOR THE DETERMINATION OF CHROMATE CONCENTRATION IN AN ALKALINE CHROMATE SOLUTION OF UNKNOWN CONCENTRATION, WHICH COMPRISES IMPREGNATING A WHITE BIBULOUS SHEET WITH AN AQUEOUS FROM THE GROUP CONSISTING OF CITRIC ACID LITER OF SOLUTION OF A CRYSTALLINE ORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF CITRIC ACID AND TARTARIC ACID AND FROM 3 TO 8 GRAMS PER LITER OF SOLUTION OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF BENZIDINE, HYDROCHLORIC ACID AND ACETIC ACID DERIVATIVES OF BENZIDINE, DRYING SAID IMPREGNATED SHEET AND PLACING A DROP OF SAID ALKALINE CHROMATE SOLUTION ON SAID DRY SHEET, THE CONCENTRATION OF SAID ACID AND OF SAID COMPOUND IN SAID SHEET BEING SUCH THAT UPON CONTACT OF SAID DROP WITH SAID SHEET A COLOR WILL DEVELOP WITHIN THE RANGE FROM BLUE THROUGH GOLDEN TO BROWNISH GOLD DEPENDING UPON THE CONCENTRATION OF THE CHROMATE IN SAID CHROMATE SOLUTION
References Cited (Backward Citations)
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Cited
US1216303A
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US1710933A
Cited
US1831894A
Cited
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Cited
US2290436A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-10-01 | 1955-04-02 | 1955-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-10-01 | 1959-04-02 | 1959-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-10-01 | 1963-04-02 | 1963-10-02 | $7700.00 | Window Closed / Lapsed |