US2837530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of salts of sulphuric acid esters of leuco vat dyestuffs of the anthraquinone series
Assignee: Durand and Huguenin AG
•
Filing: 1954-02-19
•
Granted: 1958-06-03
•
Expires: 1974-02-19
Abstract
No abstract record available.
Inventors
- 👤 Oppliger Walter
- 👤 Peyer Eduard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:26
CPC Classifications
C; C09; C09B; C09B9/00; C09B9/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
A PROCESS FOR THE MANUFACTURE OF A WATER-SOLUBLE SALT OF A SULPHURIC ACID ESTER OF A LEUCO VAT DYESTUFF OF THE ANTHRAQUINONE SERIES WHICH IS DIFFICULT TO ESTERIFY, GIVING AN ESTER YIELD OF LESS THAN 25% RELATIVE TO THE WEIGHT THEREOF WHEREIN ESTERIFIED BY MEANS OF A MIXTURE OF A-PICOLINE AND CHLOROSULPHONIC ACID (10:1 BY WEIGHT) IN THE PRESENCE OF COPPER POWDER, WHICH COMPRISES SUBJECTING THE VAT DYESTUFF, IN A MIXTURE OF AT LEAST ONE DIALKYL-FORMAMIDE OF THE GENERAL FORMULA
Claim 2
Dependent Claim
80 words
A PROCESS FOR THE MANUFACTURE OF A WATER-SOLUBLE SALT OF A SULPHURIC ACID ESTER OF A LEUCO VAT DYESTUFF OF THE ANTHRAQUINONE SERIES WHICH IS DIFFICULT TO ESTERIFY, GIVING AN ESTER YIELD OF LESS THAN 25% RELATIVE TO THE WEIGHT THEREOF WHEREIN ESTERIFIED BY MEANS OF A MIXTURE OF A-PICOLINE AND CHLOROSULPHONIC ACID (10:1 BY WEIGHT) IN THE PRESENCE OF COPPER POWDER, WHICH COMPRISES SUBJECTING THE VAT DYESTUFF, IN A MIXTURE OF AT LEAST ONE DIALKYL-FORMAMIDE OF THE GENERAL FORMULA
References Cited (Backward Citations)
US2403226A
Cited
US2506580A
Cited
US2508814A
Cited
US2604477A
Cited
GB690682A
Cited
US2705717A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-02 | 1961-12-02 | 1962-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-02 | 1965-12-02 | 1966-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-02 | 1969-12-02 | 1970-06-03 | $7700.00 | Window Closed / Lapsed |