China’s dye and pigment intermediate production
China dye and pigment intermediate production
China’s dye / pigment intermediate production has been developed since the 1950s, with the increasingly fierce competition in the market, dyeing, pigment intermediates in the production technology innovation; in the development of new varieties, improve production Technology, new methods of research, new varieties of new uses, the protection of the environment and several aspects of a breakthrough, the use of cleaning technology for dyeing, pigment intermediates production.
First, the use of intermediate development
In fact the development of intermediates in many ways, a certain intermediate used in dyes called dye intermediates, and used in pesticides, medicine, also known as pesticides, pharmaceutical intermediates. The intermediates should be considered as a branch of the fine chemical industry as a whole, and should not be rigidly divided into dye intermediates, pesticide intermediates, pharmaceutical intermediates, which would reduce the use of some intermediates and affect their development.
Fine chemical intermediates research is characterized by a wide variety, with the exception of a few varieties of large-scale production, the majority of varieties of tonnage is not great, but the preparation process is often more complex, involving many unit reaction and separation process, production also Generate a considerable amount of “three wastes” need to be properly handled. Therefore, we should engage in series of product technology research, reasonable organization of intermediate production in order to obtain good economies of scale.
From the foreign situation, the research and production of intermediates tend to focus on the series of production, a set of production equipment can produce several to a dozen intermediate varieties, such research and production through the overall development, the use of new technology It is also easier, will achieve a multiplier effect. Japan’s situation can be for our reference, the original production in the Japanese intermediate is also very scattered, from the 20th century, 60 years has been adjusted seven times, concentrated.
Through the transformation and development of China’s dyeing, pigment intermediates industry in the scale of production, technology, equipment and other aspects of a higher level, not only to meet the domestic dyeing and pigment industry development needs, but also for foreign to provide more quality Of the intermediate product.
The raw materials required for the synthesis of intermediates are mainly obtained from the products of petroleum and coking chemical industry. Most of them are benzene, naphthalene, anthraquinone compounds and some heterocyclic compounds. In recent years, compounds of heterocyclic compounds Prepared organic pigments showed an upward trend. In addition, phenanthrene, pyridine, oxyfluorene, quinoline, indole, carbazole, biphenyl series of compounds, these complex raw materials used in the manufacture of dyes, the use of synthetic materials will be more widely and universally.
Second, the most commonly used chemical reaction intermediates
The chemical reactions that are most commonly used in industrial intermediates for the processing of raw materials are as follows:
(1) sulfonation reaction
(2) nitration reaction
(3) halogenation reaction
(4) reduction reaction to prepare an amino group
(5) diazotization reaction (often accompanied by coupling reaction)
(6) The sulfonic acid group is substituted into a hydroxyl group by an alkali melting reaction
(7) acylation reaction
(8) oxidation reaction
(9) condensation and carbonation reaction
(10) Aromatization reaction (mainly amino)
(11) mutual exchange reaction of hydroxyl groups with amino groups
(12) hydroxylation or amino group
According to the fine chemical intermediates main body aromatic ring structure, intermediates can be divided into fat, benzene, naphthalene, anthraquinone, heterocyclic and fused ring system. China can produce benzene, naphthalene, anthraquinone, heterocyclic and other dyeing, pigment intermediates more than 400 varieties, basically able to meet the dye, pigment industry development needs.
Benzene varieties are:
2,4-dinitrochlorobenzene, o-nitrochlorobenzene, p-nitrochlorobenzene, p-nitrophenol, N, N-dimethylaniline, p-aminoanisole, p-nitroaniline, o-toluidine 2-bromo-6-chloro-p-nitroaniline, N-ethylaniline, m-hydroxy diethylaniline 2,4-dinitro-6-bromoaniline, o-, p-phenylenediamine, Benzoylamine, anthranilic acid, o-aminobenzenesulfonic acid, o-aminanisole, DSD acid, p-aminophenylethyl ether, CTL acid, o-cyano-p-nitroaniline, acetoacetyl o-methoxyaniline , Hydroquinone, m-phenylenediamine, N-methyl m-toluidine, N-ethyl m-toluidine, N, N-dimethyl-m-toluidine, N, N-diethylx-toluidine, -methylhydroxyethyl m-toluidine, N-ethylhydroxyethyl m-toluidine, N-methylcyanoethyl m-toluidine, N-ethylcyanoethyl m-toluidine, N-methylphenyl Toluidine, p-ethyl, ethoxyaniline, 2-4-dimethylaniline, 4-chloro-3-aminobenzamide, 4-methyl-3-aminobenzamide, 4-methoxy- Aminobenzanilide, 4-methoxy-3-amino-N, N-diethylbenzenesulfonamide, 2,4,5-trichloroaniline, m-
The main varieties of naphthalene intermediates are:
2-naphthol, H-acid, K-acid, 2,3-acid, 2,6-acid, Tobias Acid, Sulfo tobias acid, 6-nitro-1,2,4 acid, J-acid, Phenyl peri acid, NW Acid, Sodium Naphthionate, 1-naphthol-5-sulfonic acid, 1,5-dihydroxynaphthalene, 2-naphthylamine, 1-naphthol-5-sulfonic acid, 6-naphthalene dicarboxylic acid, 2R-acid and the like. The main varieties of anthraquinone intermediates are anthraquinone, 1-aminoanthraquinone, 1,4-diaminoanthraquinone, bromanine 1,5-dimethylanthraquinone, 1,5-diaminoanthraquinone, 1 Amino-5-benzoylanthraquinone, 1,5-dihydroxyanthraquinone, 1,8-hydroxyanthraquinone, 1,8-dihydroxy-4,5-diaminoanthraquinone and the like.
The main varieties of heterocyclic and fused ring are:
2-amino-6-nitrobenzothiazole, 2-amino-5,6-dichlorobenzothiazole, 2-aminothiazole, dehydrothio-p-toluidine bis 3-cyano-4-methyl-6-hydroxy-N-ethylpyridone, 3-formylamino-4-methyl-6-hydroxy-N-ethylpyridone, , 8-naphthalene anhydride, naphthalene tetracarboxylic anhydride, tetracarboxylic anhydride and the like.