Method for fixing reactive disperse dyes in low-pressure carbon dioxide medium

Abstract

The invention discloses a method for fixing reactive disperse dyes in a low-pressure carbon dioxide medium. The method is characterized in that: natural fiber textiles subjected to reactive disperse dye absorption and dyeing in a supercritical carbon dioxide fluid dyeing unit are put in a fixing unit; and in the presence of the carbon dioxide gas medium with pressure being 1.0-6.0MPa and a catalyst for fixation, the reactivity of the reactive groups of the dyes and reactive functional groups on the fibers is improved through unstable onium ion intermediate products formed by the catalyst for fixation and reactive groups of the dyes on the fibers, thus realizing catalytic fixation of the dyes on the fibers. The method has the characteristics that: the processing method of catalytic fixation in the low-pressure carbon dioxide gas medium is adopted for the dyes subjected to dyeing in the supercritical carbon dioxide fluid, thus improving the fixation efficiency of the dyes on the fibers and reducing the requirements for equipment and the investment in the equipment. The method has the advantages of simple process, high fixation efficiency and dye utilization rate, environment friendliness, high efficiency and the like.

Description

technical field [0001] The invention relates to a catalytic fixation method of active disperse dyes in a low-pressure carbon dioxide medium, in particular to a method for using a catalyst to fix active disperse dyes on natural fibers in a low-pressure carbon dioxide gas, and belongs to the technical field of textile dyeing and finishing. Background technique [0002] Supercritical carbon dioxide fluid is a green and environment-friendly fluid medium. It replaces the traditional water bath for dyeing and processing fiber textiles. It has the characteristics of environmental protection and clean production, as well as outstanding energy-saving and consumption-reducing effects. The status quo of high resource consumption, large amount of sewage discharge, and serious environmental pollution is of great significance. [0003] However, the supercritical CO of hydrophilic natural fibers, such as cotton, silk, wool and other fiber textiles, which currently account for a large marke...

AI Technical Summary

Problems solved by technology

However, the use of a large amount of solvent or organic wetting and bulking agent to pretreat the fiber takes a long time, and the residue on the fiber needs to be further processed, and the remaining solvent or auxiliary agent needs to be separated and recovered, which increases the complexity of the process. It also prolongs the process flow, and puts forward higher requirements for the explosion-proof safety of processing equipment

Adding acid to the supercritical carbon dioxide fluid can make the color fixing reaction between the dye active group and the fiber easier, but it also reduces the solubility of the dye in the supercritical carbon dioxide fluid, thereby affecting the dyeing of the dye on the fiber. amount and color yield, and the utilization rate of disperse reactive dyes in hydrophobic fluid after protonation will also decrease; in addition, the acidified supercritical carbon dioxide fluid also puts forward higher requirements on the corrosion resistance of equipment, and the color fixation reaction When the system is still in the state of supercritical carbon dioxide fluid, the pressure is relatively high; at the same time, to obtain a better dyeing effect, the dyeing processing time is often longer (4 hours or longer), indicating that the promotion effect of acid on the color fixing reaction is still not ideal

Images