Process for preparation of quinacridone series pigments

A technology of quinacridone and dihydroquinacridone, which is applied in quinacridone, chemical instruments and methods, azo dyes, etc., can solve the problems of many by-products, complex process, and large influence of pigment color light, etc., to achieve The effect of product quality assurance, simplification of process and improvement of production efficiency

Inactive Publication Date: 2004-08-18
余世春 +1
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Problems solved by technology

In the above method, there are many by-products, which have a great

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  • Process for preparation of quinacridone series pigments
  • Process for preparation of quinacridone series pigments
  • Process for preparation of quinacridone series pigments

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[0025] Preparation of Quinacridone

[0026] Step 1, condensation

[0027] Method 1: Dissolve 30 g of dimethyl succinyl succinate in 150 ml of ethanol, add 3 ml of concentrated hydrochloric acid and 26 g of aniline, and heat and reflux for 5 hours under nitrogen protection. Precipitate a large amount of orange-yellow solid, filter after cooling, wash the excess aniline with 0.5% dilute hydrochloric acid, wash with water until neutral, dry to obtain 1,4-(N-phenyl)-2,5-dicarboxylic acid dimethyl ester , the yield is 92%, and the content is 96-97%.

[0028] Method 2: Dissolve 30 g of dimethyl diacylsuccinate in 150 ml of ethanol, add 3 ml of concentrated hydrochloric acid and 30 g of p-methylaniline, and heat up and reflux for 5 hours under nitrogen protection. Precipitate a large amount of yellow-green solid, filter after cooling, wash the excess methylaniline with 0.5% dilute hydrochloric acid, wash with water until neutral, and dry to obtain 1,4-(N-p-tolylamino)-2,5-dicarboxy...

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Abstract

The present invention discloses the preparation process of serial quinacridone dyes. The preparation process includes the first condensation of diacyl dimethyl succinate and aniline derivative in ethanol under the catalysis of hydrochloric acid to obtain 1, 4-(N-phenyl amino)-2, 5-dimethyl carboxylate; direct cyclization of 1, 4-(N-phenyl amino)-2, 5-dimethyl carboxylate under the action of phosphoric acid polymer to produce dihydroquinacridone; and final chemical oxidation or hydrogenating aromatization and cyclization under catalysis of Pt catalyst of dihydroquinacridone in the condition of being favorable to form aromatic nucleus to produce quinacridone. The process of the present invention has low reaction temperature and mild reaction condition, and the product has no deep colored impurity produced and no need of purification and crystal transformation in obtaining dye with required hue and crystal form.

Description

technical field [0001] The invention relates to a method for synthesizing organic pigments, in particular to a method for preparing quinacridone series pigments. Background technique [0002] Quinacridone was known as early as 1935. At that time, Mobey Company of the United States produced Quino magenta as a dye colorant for paint and plastic coloring. Method to manufacture quino-quino coloring agent, later workers have more in-depth research on oxidation, but high-temperature cyclization is difficult to avoid carbonization, the color of the final product is not bright, and this process cannot produce real and practical pigments. Twenty years later, after five years of hard work by the Bayer Company of the United States, it was not until 1958 that the method of producing stable particles of different crystal forms was proposed by it, that quinacridone came out as a pigment and became the best weather resistance in the red series. branch, widely used. [0003] The productio...

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Application Information

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IPC IPC(8): C09B48/00
Inventor 钱昆
Owner 余世春
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