US3974136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modified form of a disazo pigment
Assignee: Hoechst AG
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Filing: 1974-01-17
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Granted: 1976-08-10
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Expires: 1994-01-17
Abstract
Abstract The disazo pigment of the formula ##SPC1## Characterized by a specific surface of 12 - 20, preferably 13 - 18 m 2 /g, a maximum of the distribution of the grain sizes of between 500 and 1000 nm and a proportion of these grain sizes in the total distribution of between 35 and 65 %. This disazo pigment is obtained by isolating the pigment, after coupling, by stirring it out with alkali and, after having filtered it and washed it to neutrality, heating it to temperatures above 100° C in a mixture of water and a solvent which is immiscible with water or miscible with water to a limited degree only.
Inventors
- 👤 Klaus Hunger
- 👤 Joachim Ribka
- 👤 Wolfgang Rieper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:10
CPC Classifications
C; C09; C09B; C09B35/00; C09B35/02; C09B35/039; C09B35/08; C09B35/10; C09B35/105; C09B67/00; C09B67/0001; C09B67/0014; C09B67/0015
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
49 words
A disazo pigment of the formula ##SPC4## characterized by a specific surface of 12 - 20 m 2 /g, a maximum of the grain size distribution of between 500 and 1000 nm and a proportion of these grain sizes in the total distribution of between 35 and 65 %.
Claim 2
Dependent Claim
49 words
A disazo pigment of the formula ##SPC4## characterized by a specific surface of 12 - 20 m 2 /g, a maximum of the grain size distribution of between 500 and 1000 nm and a proportion of these grain sizes in the total distribution of between 35 and 65 %.
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) | 1979-08-10 | 1980-02-09 | 1980-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-10 | 1984-02-09 | 1984-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-10 | 1988-02-09 | 1988-08-10 | $7700.00 | Window Closed / Lapsed |