Preparation method of organic pigment with high covering power and light fastness reaching grade 7 or above and applied to coating

Abstract

The invention discloses a preparation method of an organic pigment which has high covering power and light fastness of more than grade 7 and is applied to a coating, and relates to the technical field of organic pigments. The preparation method comprises the following steps: 1, adding distilled water into a reaction container with stirring and temperature control functions, controlling the temperature of the distilled water to be in a low-temperature state, adding a concentrated acid aqueous solution into the distilled water, stirring, adding a reactant A into the reaction container after the temperature is reduced to be in the low-temperature state, and reacting for 2-4 hours; stirring at a constant temperature until the reactant A is completely dissolved to obtain a reaction solution B; according to the invention, by selecting synthetic raw materials with chlorine groups, nitryl groups and sulfurous acid groups, the activity of diazonium salt is relatively high, so that later coupling is facilitated, meanwhile, after the organic pigment is formed through coupling, due to the fact that the chlorine groups, the nitryl groups and the sulfurous acid groups have relatively strong electrophilicity, the performance of a synthesized azo bond is relatively stable; and macroscopically, the color fastness to light is relatively good.

Description

technical field [0001] The invention relates to the technical field of organic pigments, in particular to a method for preparing organic pigments with high hiding power and light fastness reaching grade 7 or above for coatings. Background technique [0002] Organic pigments refer to insoluble organic substances, which are usually added to the substrate in a highly dispersed state to color the substrate. The fundamental difference between it and dyes is that dyes are soluble in the dyeing medium used, while pigments are neither soluble in the medium in which they are used nor in the substrate to be colored. [0003] With the improvement of people's living standards and the increase of environmental awareness, consumers in the current market tend to use more environmentally friendly water-based paints. In the production process of water-based paints, due to the combination of traditional azo organic pigments with water-based solvents Poor performance, which makes it difficult...

AI Technical Summary

Problems solved by technology

[0003] With the improvement of people's living standards and the increase of environmental awareness, consumers in the current market tend to use more environmentally friendly water-based paints. In the production process of water-based paints, due to the combination of traditional azo organic pigments with water-based solvents Poor performance, which makes it difficult for most azo organic pigments to disperse uniformly in water-based solvents, resulting in poor hiding power macroscopically. The fastness performance is poor, so a method for preparing organic pigments with high hiding power and light fastness of more than 7 grades for coatings is proposed

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