US2580737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cobalt chloride humidity indicator
Assignee: Davison Chemical Corp
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Filing: 1949-01-19
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Granted: 1952-01-01
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Expires: 1969-01-19
Abstract
No abstract record available.
Inventors
- 👤 Davis Paul Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:33
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/222
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
87 words
A METHOD OF MANUFACTURING A QUANTITATIVE RELATIVE HUMIDITY INDICATOR ADAPTED TO CHANGE COLOR WHEN THE RELATIVE HUMIDITY OF THE ATMOSPHERE TO WHICH IT IS EXPOSED IS CHANGED FROM BELOW ABOUT 50-60% THROUGH THAT RANGE COMPRISING FORMING A SILICA HYDROGEL, TREATING THE HYDROGEL WITH AN AMMONIACAL SOLUTION TO FORM A WIDE PORE SILICA GEL, IMPREGNATING THE WIDE PORE SILICA GEL WITH A SOLUTION OF COBALT CHLORIDE SO THAT THE IMPREGNATED GEL HAS A COBALT CHLORIDE CONTENT OF ABOUT 2-5% ON A DRY BASIS, AND DRYING THE IMPREGNATED GEL.
Claim 2
Independent Claim
87 words
A METHOD OF MANUFACTURING A QUANTITATIVE RELATIVE HUMIDITY INDICATOR ADAPTED TO CHANGE COLOR WHEN THE RELATIVE HUMIDITY OF THE ATMOSPHERE TO WHICH IT IS EXPOSED IS CHANGED FROM BELOW ABOUT 50-60% THROUGH THAT RANGE COMPRISING FORMING A SILICA HYDROGEL, TREATING THE HYDROGEL WITH AN AMMONIACAL SOLUTION TO FORM A WIDE PORE SILICA GEL, IMPREGNATING THE WIDE PORE SILICA GEL WITH A SOLUTION OF COBALT CHLORIDE SO THAT THE IMPREGNATED GEL HAS A COBALT CHLORIDE CONTENT OF ABOUT 2-5% ON A DRY BASIS, AND DRYING THE IMPREGNATED GEL.
References Cited (Backward Citations)
US2460071A
Cited
US2477695A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-31 | 1955-07-02 | 1956-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-31 | 1959-07-02 | 1960-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-31 | 1963-07-02 | 1964-01-01 | $7700.00 | Window Closed / Lapsed |