A method for preparing transparent pigment yellow 180

Abstract

The invention discloses a method of preparing transparent pigment yellow 180. The method comprises the following steps: preparing a diazotization solution, preparing a coupling solution, preparing a buffer solution through ammonium chloride and ammonia water, controlling the pH to 7-7.5, adding bi-octadecyl-dimethyl ammonium chloride, firstly, dripping 1 / 20-1 / 8 of the coupling solution, simultaneously dripping the diazotization solution and the coupling solution, controlling the dripping reaction time to 15 minutes to 8 hours, and controlling the reaction temperature to 10-50 DEG C; continuing to stir after dripping the solutions to ensure a complete coupling reaction, filtering and washing to remove the inorganic salt and a part of water-soluble impurities to obtain a crude product, adding an assistant and water, heating, and finally, filtering, drying and crushing to obtain a finished product. The method generates little production in the production process, the cost is low, the produced pigment is uniform in particle diameter distribution, the particles are soft, the crystal structure and crystal size are uniform with the product treated by an organic solvent, and the product is high in color strength, bright in color and excellent in light resistance and solvent resistance. The acylamino in the groups of the pigment yellow 180 greatly improves the combination firmness of the molecules, thereby improving such properties as solvent resistance, heat resistance, and the like.

Description

technical field [0001] The invention relates to a method for preparing a pigment, in particular to a method for preparing transparent pigment yellow 180. Background technique [0002] C.I.P.Y180 (Pigment Yellow 180) belongs to benzimidazolone pigments, CAS.NO: 77804-81-0 and its molecular formula is: [0003] [0004] The early azo pigments had simple structure, small molecular weight and low color fastness. The solvent fastness, light fastness and weather fastness cannot be compared with high-performance pigments. The raw material for its preparation is mainly BAPE (ethylene glycol (2,2'-diamino) diphenyl ether), and the coupling solution is AABI (5-acetoacetamido benzimidazolone). The preparation method is the same as that of general benzimidazolone The pigment is similar to the German patent (DE2347532). First diazotization reaction, dissolving the coupling solution, and then using cis-coupling to synthesize the crude product pigmentation treatment, such as heat tre...

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Problems solved by technology

First diazotization reaction, dissolving the coupling solution, and then using cis-coupling to synthesize crude product pigmentation treatment, such as heat treatment in organic solvent isobutanol and DMF, see European patent (ep10212) and US patent US4370269, the shortcomings of these processes The disadvantages are that the color of the prepared pigments is not bright enough, the tinting strength is relatively average, in addition, the process is long, the energy consumption is high, and the solvent recovery is difficult. The most important thing is that the pigments prepared by these methods are of high hiding power. The application in ink is limited, so it will be of great significance to research and develop a new method for preparing transparent pigment yellow 180.

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