Patent US3669994A successfully refreshed from Google Patents.
US3669994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anthraquinone dyestuffs
Assignee: Imperial Chemical Industries Ltd
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Filing: 1970-01-06
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Granted: 1972-06-13
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Expires: 1990-01-06
Abstract
Abstract Mixtures of disperse anthraquinone dyestuffs which are obtained by reacting a leuco derivative of a 1:5-dihydroxy-4:8-di(amino, hydroxy or alkylamino) -2-(hydroxyaryl or alkoxyaryl)anthraquinone with an aldehyde, and the use of the said mixtures for coloring synthetic textile materials.
Inventors
- 👤 Edwin Dennis Harvey
- 👤 Frank Lodge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:59
CPC Classifications
C; C09; C09B; C09B1/00; C09B1/50; C09B1/503; C09B1/51; C09B1/515
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
16 words
The mixture of water-insoluble dyestuffs of claim 1 wherein the leuco derivative of 1:5-dihydroxy-4:8-diamino-2-(4''-hydroxyphenyl)anthraquinone is employed.
Claim 2
Dependent Claim
16 words
The mixture of water-insoluble dyestuffs of claim 1 wherein the leuco derivative of 1:5-dihydroxy-4:8-diamino-2-(4''-methoxyphenyl)anthraquinone is employed.
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) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |