Solvent process for recovering indigo dye from textile scrap
First Claim
1. A process for recovering a vat dye from a cotton textile using an organic solvent, comprising the steps ofa) contacting the textile with a heated organic solvent in which the dye is soluble until dye is extracted from the textile into the solvent to produce a dye-containing solvent solution;
- andb) precipitating dye from the dye-containing solvent solution by cooling said solvent solution.
13 Assignments
0 Petitions
Accused Products
Abstract
A process for recovering a vat dye from a textile using a heated organic solvent. The textile is contacted with a heated organic solvent in which the dye is soluble until dye is extracted from the textile into the solvent to produce a dye-containing solvent solution. The dye is then recovered from the organic solvent by evaporation of the solvent leaving a dye residue, cooling and precipitation of the dye, or extraction of the dye by contacting the dye-containing solvent solution with an aqueous solution containing a reducing agent for the dye. When dye is extracted from the dye-containing solvent solution by contacting it with an aqueous solution containing a reducing agent, the dye is subsequently insolubilized by oxidation, and the dye is recovered from the aqueous dye solution. This process is particularly advantageous for recovering indigo dye from denim scrap.
-
Citations
21 Claims
-
1. A process for recovering a vat dye from a cotton textile using an organic solvent, comprising the steps of
a) contacting the textile with a heated organic solvent in which the dye is soluble until dye is extracted from the textile into the solvent to produce a dye-containing solvent solution; - and
b) precipitating dye from the dye-containing solvent solution by cooling said solvent solution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
- and
Specification