LIGNIN DYE DISPERSANT WITH CARBOXYL AND SULFONIC GROUPS AND PREPARATION METHOD THEREFOR

摘要

Disclosed are a lignin dye dispersant with carboxyl and sulfonic groups and a preparation method therefor. The method comprises: adding an alkaline lignin solid powder into water to formulate a solution with the concentration of 20-50 wt.%; adding a sulfonic group-containing monomer and an initiator at 75-100 ℃ to react for 1-2 h to obtain a sulfonic lignin; formulating an aqueous solution of a carboxylic acid compound with the concentration of 10-40 wt.%; adding dropwise epichlorohydrin at 30-80 ℃ and the pH value of 4-7 to react for 1-3 h to obtain a hydroxypropyl carboxylic acid compound; mixing both of the intermediates to carry out a copolymerization reaction at 80-100 ℃ and the pH value of 8-12 for 0.5-3 h; adding a hydroxyketone compound with the concentration of 20-30 wt.% to react for 2-6 h and obtaining a liquid product after the reaction ending. The dispersant has more sulfonic and carboxyl groups, higher molecular weight and less phenolic hydroxyl, and it can enhance the dispersibility of the dye and reduce the reducing capacity to azo dyes and contamination to fibers.