US3960740A
Expired / Lapsed
US
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Antifreeze composition
Assignee: BASF Corp
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Filing: 1974-01-04
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Granted: 1976-06-01
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Expires: 1994-01-04
Abstract
Abstract Antifreeze compositions are provided which contain glycol-water concentration indicators. When used in motor vehicle radiators, the indicators in the compositions enable the motorist at a glance to determine when the glycol level has been reduced. The indicators are colored moieties, i.e., dyes, which have at least one substituent which will give a differential solubility at different glycol-water concentrations. Preferred substituents are hydroxy groups and amino groups and the preferred colored moiety is an anthraquinone dye.
Inventors
- 👤 William Lawrence Truett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:50
CPC Classifications
C; C09; C09K; C09K5/00; C09K5/20; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/203332
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
76 words
In an undiluted antifreeze solution containing polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycols, butylene glycols and glycerol, an effective amount of corrosion inhibitor and a dye, the improvement which comprises using as the dye, 1,2-diamino anthraquinone, said dye being present in said antifreeze solution in an amount that is sufficient to give a deep color when said solution is diluted with water to a polyhydric alcohol-water solution of 50-50 volume percent.
Claim 2
Dependent Claim
76 words
In an undiluted antifreeze solution containing polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycols, butylene glycols and glycerol, an effective amount of corrosion inhibitor and a dye, the improvement which comprises using as the dye, 1,2-diamino anthraquinone, said dye being present in said antifreeze solution in an amount that is sufficient to give a deep color when said solution is diluted with water to a polyhydric alcohol-water solution of 50-50 volume percent.
Claim 3
Dependent Claim
29 words
The antifreeze solution of claim 1 wherein the polyhydric alcohol is ethylene glycol and from 0.2 to 2 grams per gallon of antifreeze solution of 1,2-diamino anthraquinone is used.
Claim 4
Dependent Claim
26 words
The antifreeze solution of claim 2 wherein the antifreeze solution contains from about 90 to 96 weight percent ethylene glycol and alkali metal tetraborate corrosion inhibitor.
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) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |