US2821525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Azo coloring matters
Assignee: Wyeth Holdings LLC
•
Filing: 1953-04-07
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Granted: 1958-01-28
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Expires: 1973-04-07
Abstract
No abstract record available.
Inventors
- 👤 Waitkins George Raymond
- 👤 Lacey Harold Talbot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:39
CPC Classifications
C; C09; C09B; C09B63/00; C09B63/005; Y; Y10; Y10S; Y10S534/00; Y10S534/01
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
35 words
A LIGHT AND HEAT STABLE RED TO MAROON PIGMENTARY SUBSTANCE CONSISTING ESSENTIALLY OF THE WATER-INSOLUBLE METALLIC SALTS OF THE AZO DYESTUFF FOUND UPON DIAZOTIZATION OF 3,4-DICHLOROANILINEMONOSULFONIC ACID AND COUPLING OF SAID ACID WITH 2-HYDROXY-3-NAPHTHOIC ACID.
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) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |