The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 2000
Filed:
Feb. 02, 1998
Robert T Patton, Lake Jackson, TX (US);
David Hall, Auburn, TX (US);
American Renewable Resources LLC, Burlingame, CA (US);
Abstract
A process for decolorizing a cellulose textile bearing oxidized vat dye comprising contacting the cellulose textile with an aqueous solution of hydrogen peroxide containing an amount of a hydrogen peroxide catalyst sufficient to oxidize vat dye in the fabric until the dye is decolorized by oxidation. Then the cellulose textile is separated from the aqueous solution. The hydrogen peroxide catalyst can be a water-soluble lower alkyl quaternary amine salt such as a dihydroxypropyltrimethylammonium halide, chlorohydroxypropyltrimethylammonium halide or epoxypropyltrimethylammonium halide, or it can be a transition metal ion such as a cupric or stannous metal ion present in an amount of from 0.1 to 2 ppm. The process is suitable for decolorizing denim bearing vat dyes such as indigo, and is particularly suitable for decolorizing denim scrap.