Method for improving cationized modification evenness of cotton fabrics

Abstract

The invention belongs to the technical field of dyeing and finishing, relating to a method for improving the cationized modification evenness of cotton fabrics. The method comprises the following steps: (1) preparing modified solution by utilizing modifier containing reactive groups and cationic groups, placing the cotton fabrics in the modified solution, heating the solution to the temperature of between 85 and 95 DEG C, and preserving the temperature for 20 to 30 minutes; and (2) cooling the mixture system obtained in the step (1) to the temperature of between 30 and 40 DEG C, adding caustic soda in the mixture system to ensure that the concentration of the mixture system in the solution reaches 0.5 to 1g/L, reacting for 20 to 30 minutes, and taking out and washing the cotton fabrics with water. The double-temperature modification process ensures that the cationic modifier is diffused and homogenized in the high-temperature neutral condition, and reacts and combines with the cotton fibers in the low-temperature strong alkali condition, thus reducing modifying unevenness caused by hydrolysis loss and excessive reaction velocity of the modifier in the high-temperature alkali condition, or reducing the problem of poor modifying evenness and penetration of the modifier in the low temperature condition.

Description

technical field [0001] The invention belongs to the technical field of dyeing and finishing, and relates to a method for improving the uniformity of cationic modification of cotton fabrics. Background technique [0002] Cotton fiber dyeing with reactive dyes usually includes two stages of dyeing and fixation. "Dyeing" refers to the adsorption and diffusion of dyes on the fibers, and "fixation" refers to the reaction of the active groups in the dyes with the nucleophilic groups on the cotton fibers after alkali addition and covalent bonding. Due to the low directness of reactive dyes and the electrostatic repulsion between dye anions and cotton fibers, the dye uptake rate is low. Usually, it is necessary to add a large amount of neutral salt to promote dyeing to achieve a higher dye uptake rate, but then cause salt pollution. The cationic modification of cotton fiber can introduce cationic groups on the cotton fiber, reduce the Zeta potential on the surface of cotton fiber,...

AI Technical Summary

Problems solved by technology

Because the reaction rate between the modifier and cotton fiber is very fast, and once reacted, the modifier cannot move, and it is easy to produce uneven modification, resulting in uneven dyeing

If the temperature of the entire modification process is lowered, it will be difficult for the modifier to diffuse into the interior of the fiber, resulting in only surface coloring during dyeing and poor penetration.

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