USING POLAR ORGANIC SOLVENTS FOR PURIFICATION AND AQUEOUS INK PREPARATION OF TEXTILE GRADE WATER SOLUBLE DYES
Original Publication Date: 2001-Jun-30
Included in the Prior Art Database: 2004-Apr-09
Xerox Disclosure Journal
Textile grade dyes typically contain significant amounts of excess salts from the dye preparation process. Particularly high-grade dyes are normally utilized to ensure consistently acceptable jetting performance for Thermal Ink Jet (TLT). The cost and availability of these purified dyes is high and limited. An inexpensive process for removal of the bulk salts that renders the dye dissolved in the preferred organic co-solvent for TLT aqueous based inks dissolves the crude dye stuff into neat solvent and collects the dye laden supernatant liquid. Preferred organic solvents include formamide and dimethyl sulfoxide (DMSO). Both cationic and anionic dye types are applicable.