US2745720A
Expired / Lapsed
US
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Acid-base indicator dyestuffs
Assignee: BASF Schweiz AG
•
Filing: 1952-08-25
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Granted: 1956-05-15
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Expires: 1972-08-25
Abstract
No abstract record available.
Inventors
- 👤 Schwarzenbach Gerold
- 👤 Sallmann Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:19
CPC Classifications
C; C09; C09B; C09B69/00; C09B11/00; C09B11/04; C09B11/06; C09B11/08; C09B43/00; G; G01; G01N; G01N31/00; G01N31/22; G01N31/221; Y; Y10; Y10T; Y10T436/00; Y10T436/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
14 words
A DERIVATIVE OF AN ACID-BASE INDICATOR DYESTUFF, WHICH CONTAINS THE RADICAL OF THE FORMULA
Claim 2
Dependent Claim
14 words
A DERIVATIVE OF AN ACID-BASE INDICATOR DYESTUFF, WHICH CONTAINS THE RADICAL OF THE FORMULA
References Cited (Backward Citations)
US2122409A
Cited
FR48570E
Cited
US2583891A
Cited
US2562198A
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US2624757A
Cited
US2624759A
Cited
US2624756A
Cited
US2624758A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-05-15 | 1959-11-14 | 1960-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-15 | 1963-11-14 | 1964-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-15 | 1967-11-14 | 1968-05-15 | $7700.00 | Window Closed / Lapsed |