A preparation method of brilliant blue light red organic pigment c.i.p.r.185

Abstract

The invention discloses a preparation method of a brilliant-blue-light red organic pigment C.I.P.R.185, belonging to the technical field of pigment preparation. The method comprises the following steps: carrying out diazo-reaction in an acetic acid system, and adding a surfactant in the process of diazotization and coupling component dissolution to facilitate the dispersion in the coupling process, wherein parallel-flow coupling is adopted, the buffer solution adopts an ammonium chloride-ammonia water system, and the pH value of the buffer system is controlled at 7-9; and washing after the coupling is finished, dispersing the press cake with water, adding a surfactant, carrying out pressure filtration, washing, drying and pulverizing to obtain the pigment finished product. The finished product pigment prepared by the method has the advantages of high purity, fewer impurities, high staining power, loose and soft particles and bright color light; and since no after-treatment is performed in the organic solvent, the invention greatly reduces the energy consumption, lowers the cost, reduces the consumption of inflammable and explosive materials, enhances the safety, has favorable economic benefit, and is suitable for popularization in production.

Description

technical field [0001] The invention belongs to the technical field of pigment preparation, in particular to a method for preparing a brilliant blue light red organic pigment C.I.P.R.185. Background technique [0002] C.I.P.R.185 belongs to azo pigments, its CAS.NO.: 51920-12-8, its molecular formula is as follows: [0003] [0004] Its molecules contain , so it is customarily called benzimidazolone pigments. Although they belong to azo pigments in chemical classification, their application performance and various fastnesses cannot be compared with other azo pigments; The fastness of the items is very good, and the main raw materials for the preparation are methanesulfonamide crixidin and naphthol ASBI. The basic chemical synthesis of C.I.P.R.185 is relatively simple and direct, but the difference between pigment chemistry and general fine chemical industry is that not only the product must be synthesized, but also its crystal form and particle original particle size a...

AI Technical Summary

Problems solved by technology

In the traditional preparation method, cis-coupling is generally adopted, that is, naphtheol ASBI is dissolved with alkali, and then it is precipitated into fine particles with acid, and then the prepared diazonium salt is added to the coupling component. The disadvantage of this method is that The solubility of naphthalene ASBI in neutral water is very small, and in the process of pigment formation, the generated fine pigment will wrap the unreacted ASBI, causing the diazonium salt to fail to react in time, and then self-coupling occurs, resulting in impurities; in the patent In CN1995149, segmental coupling is adopted, that is, when the coupling reaches 80-90%, the pH is adjusted to a strong alkali, and then the chromol ASBI is separated out again. Although the core-wrapping problem has been solved, the acid-base consumption is very large, which increases the cost. The pH is unstable, and the performance of the pigment is not good; in the Japanese patent JP2003128948, a surfactant is added before the precipitation of the coupling solution to make the precipitated particles finer and increase the reaction area, but there is still the problem of core wrapping, and the pigmentation after synthesis Using solvent treatment, due to solvent recovery, there are still problems such as high energy consumption and long working hours

Images