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US5586992A
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Dyeing cellulose-containing textile material with hydrogenated indigo
Assignee: Dystar Colours Distribution GmbH
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Filing: 1994-03-21
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Granted: 1996-12-24
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Expires: 2014-03-21
Abstract
Abstract A process for dyeing celluose-containing textile material with indigo comprises using an aqueous solution of leuco indigo prepared by catalytic hydrogenation and, after the leuco indigo has gone onto the textile material, converting it back into the pigment form in a conventional manner by air oxidation.
Inventors
- 👤 Georg Schnitzer
- 👤 Franz Suetsch
- 👤 Michael Schmitt
- 👤 Erich Kromm
- 👤 Harald Schlueter
- 👤 Rudolf Krueger
- 👤 Andreas Weiper-Idelmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:18
CPC Classifications
C; C09; C09B; C09B7/00; C09B7/02; D; D06; D06P; D06P1/00; D06P1/22; D06P1/221; D06P1/228; D06P5/00; D06P5/20; D06P5/2016; Y; Y10; Y10S; Y10S8/00; Y10S8/916; Y10S8/918
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
62 words
A process for dyeing cellulose-containing textile material with indigo which comprises a) introducing into a dyebath an aqueous solution of leuco indigo prepared by catalytic hydrogenation; b) contacting the textile material with the dyebath; and, after the leuco indigo has gone onto the textile material, c) converting said leuco indigo back into the pigment form in a conventional manner by air oxidation.
Claim 2
Dependent Claim
62 words
A process for dyeing cellulose-containing textile material with indigo which comprises a) introducing into a dyebath an aqueous solution of leuco indigo prepared by catalytic hydrogenation; b) contacting the textile material with the dyebath; and, after the leuco indigo has gone onto the textile material, c) converting said leuco indigo back into the pigment form in a conventional manner by air oxidation.
Claim 3
Dependent Claim
22 words
A process as claimed in claim 1 wherein the leuco indigo solution contains from 10 to 35% by weight of leuco indigo.
Claim 4
Dependent Claim
21 words
A process as claimed in claim 1 wherein the leuco indigo solution contains from 2 to 10% by weight of alkali.
Claim 5
Dependent Claim
22 words
A process as claimed in claim 1 wherein the leuco indigo solution contains from 2 to 10% by weight of sodium hydroxide.
Claim 6
Dependent Claim
66 words
A process for dyeing cellulose-containing textile material with indigo which comprises using an aqueous solution of leuco indigo prepared by catalytic hydrogenation and, after the leuco indigo has gone onto the textile material, converting the leuco indigo back into the pigment form by air oxidation, wherein the leuco indigo oxidized during dyeing by air contact is electrochemically reduced in the dyeing liquor using a mediator system.
Claim 7
Dependent Claim
66 words
A process for dyeing cellulose-containing textile material with indigo which comprises using an aqueous solution of leuco indigo prepared by catalytic hydrogenation and, after the leuco indigo has gone onto the textile material, converting the leuco indigo back into the pigment form by air oxidation, wherein the leuco indigo oxidized during dyeing by air contact is electrochemically reduced in the dyeing liquor using a mediator system.
Claim 8
Dependent Claim
16 words
A process as claimed in claim 5 wherein the mediator used is a transition metal complex.
Claim 9
Dependent Claim
24 words
A process as claimed in claim 5 wherein the mediator used is an organic redox system which is substantially reversible under the dyeing conditions.
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) | 1999-12-24 | 2000-06-24 | 2000-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-24 | 2004-06-24 | 2004-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-24 | 2008-06-24 | 2008-12-24 | $7700.00 | Window Closed / Lapsed |