Patent US4013414A successfully refreshed from Google Patents.
US4013414A
Expired / Lapsed
US
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Indicator dye
Assignee: General Electric Co
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Filing: 1975-05-05
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Granted: 1977-03-22
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Expires: 1995-05-05
Abstract
Abstract A novel class of soluble organic nitrogen compounds which produces various colors when dissolved in organic liquid solvents. These dyes produce a color from blue to red if the organic liquid medium has a neutral or basic pH which reversibly changes to yellow if the liquid medium has an acid pH. The color variation can also serve as an indication of solvent polarity.
Inventors
- 👤 Francois A. Lavallee
- 👤 Donald G. LeGrand
- 👤 George L. Gaines, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:22
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/221
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
66 words
A method of identifying the acid condition of a liquid medium employing an organic solvent which comprises dissolving in said liquid medium a quantity of a soluble dye having the general formula ##STR3## wherein R is an aliphatic hydrocarbon radical having approximately 12 to 20 carbon atoms so that color changes shift to longer wavelengths with increasing polarity of solvent and observing the color produced thereby.
Claim 2
Independent Claim
66 words
A method of identifying the acid condition of a liquid medium employing an organic solvent which comprises dissolving in said liquid medium a quantity of a soluble dye having the general formula ##STR3## wherein R is an aliphatic hydrocarbon radical having approximately 12 to 20 carbon atoms so that color changes shift to longer wavelengths with increasing polarity of solvent and observing the color produced thereby.
Claim 3
Dependent Claim
14 words
A method as in claim 1 wherein the liquid medium includes an aromatic solvent.
Claim 4
Dependent Claim
15 words
A method as in claim 1 wherein the liquid medium includes an organic polar solvent.
Claim 5
Dependent Claim
24 words
A method as in claim 3 wherein the liquid medium includes a short chain aliphatic hydrocarbon solvent having from 1 to 6 carbon atoms.
Claim 6
Independent Claim
79 words
A method of identifying the concentration of a particular organic solvent in a liquid medium employing mixed organic solvents which comprises dissolving in said liquid medium a quantity of a soluble dye having the general formula ##STR4## wherein R is an aliphatic hydrocarbon radical having approximately 12 to 20 carbon atoms so that color changes shift to longer wavelengths with increasing polarity of solvent and measuring the wavelength of maximum optical absorption of visible light in said liquid medium.
Claim 7
Independent Claim
79 words
A method of identifying the concentration of a particular organic solvent in a liquid medium employing mixed organic solvents which comprises dissolving in said liquid medium a quantity of a soluble dye having the general formula ##STR4## wherein R is an aliphatic hydrocarbon radical having approximately 12 to 20 carbon atoms so that color changes shift to longer wavelengths with increasing polarity of solvent and measuring the wavelength of maximum optical absorption of visible light in said liquid medium.
Claim 8
Dependent Claim
14 words
A method as in claim 5 wherein the liquid medium includes an aromatic solvent.
Claim 9
Dependent Claim
15 words
A method as in claim 5 wherein the liquid medium includes an organic polar solvent.
Claim 10
Dependent Claim
24 words
A method as in claim 10 wherein the liquid medium includes a short chain aliphatic hydrocarbon solvent having from 1 to 6 carbon atoms.
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) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |