Preparation method of cationic liquid dye

Abstract

The invention discloses a preparation method of a cationic liquid dye. The method comprises the following steps: by taking a target dye molecular parent as a starting raw material, dimethyl sulfate asa methylation reagent and weakly alkaline inorganic oxide as an acid-binding agent, carrying out methylation reaction in a weakly acidic system to methylate the target dye molecular parent into target dye molecules; adding water and an organic solvent which is immiscible with water into the system, heating to dissolve, extracting to allow inorganic salt ions to be extracted into a water phase, cooling to room temperature, standing for phase splitting, separating out the water phase, concentrating the organic phase to recover the organic solvent, and preparing the cationic liquid dye from theremaining organic matters. The method is simple and convenient to operate, can be better applied to industrial production, is low in cost, is green and environment-friendly in the whole technologicalprocess, improves the application performance of the existing product, and enlarges the application range of the existing product.

Description

technical field [0001] The invention relates to a preparation method of a cationic liquid dye, belonging to the technical field of dyes. Background technique [0002] At present, the preparation method of the existing cationic liquid dyes (blue-159, red-46, blue-41) is to use the target dye molecular matrix as the starting material and dimethyl sulfate as the methylating reagent to carry out methylation in a weakly acidic system. The methylation reaction methylates the target dye molecular precursor into the target dye molecule, and then standardizes and prepares it as a standardized commercial liquid dye. [0003] A kind of weakly basic inorganic oxide (magnesium oxide) as an acid-binding agent is applied in the current synthesis and preparation process. The existence of this acid-binding agent can make the methylation reaction proceed smoothly and completely, and the obtained liquid dye can be used in General paper, acrylic, polyester and other general materials are dyed,...

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Problems solved by technology

[0003] A kind of weakly basic inorganic oxide (magnesium oxide) as an acid-binding agent is applied in the current synthesis and preparation process. The existence of this acid-binding agent can make the methylation reaction proceed smoothly and completely, and the obtained liquid dye can be used in Dyeing of ordinary paper, acrylic, polyester and other common materials, but for the dyeing of special materials (such as wigs), the acetone insoluble index is too high, which greatly reduces the dyeing performance, further restricting the application of the product

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