Whatsapp/wechat:+86 13805212761

https://www.mit-ivy.com

mit-ivy industry company
CEO@mit-ivy.com
hi , this is CEO athena from mit-ivy industry for chemical in china.
Intermediates: Dyestuff intermediates are an extremely important branch of the fine chemical industry, and the rapid development of the dyestuff industry depends on the development of the intermediates that go with it.
The production of dyestuff and pigment intermediates in China has been developed significantly since the 1950s. With the increasingly fierce competition in the market, dyestuff and pigment intermediates have been innovated in production technology; they have made breakthroughs in several aspects such as developing new varieties, improving production process, researching new methods, new uses of old varieties, protecting the environment, etc., and adopting clean technology for the production of dyestuff and pigment intermediates.
1
The development of intermediates’ use

In fact, the use of intermediates development is multifaceted, a certain intermediate used in dyestuff called dye intermediates, and used in pesticides, pharmaceuticals and called pesticides, pharmaceutical intermediates. Intermediates should be considered as a branch of the fine chemical industry as a whole, should not be rigidly divided into dyestuff intermediates, pesticide intermediates, pharmaceutical intermediates by industry, which will reduce the scope of use of some intermediates and affect their development.

Fine chemical intermediates research is characterized by a wide range of varieties, in addition to a few varieties of production scale is particularly huge, most varieties of tonnage are not very large, but the preparation process is often complex, involving many unit reactions and separation process, production also generated a considerable number of “three wastes” need to be properly handled. Therefore, we should engage in the process research of series products and organize the production of intermediates reasonably in order to obtain good scale benefits.

From the situation of foreign countries, the research and production of intermediates tend to be properly concentrated to achieve series production, a set of production equipment can produce several to a dozen varieties of intermediates, such research and production through the overall development, the use of new technology is easier to implement, will achieve twice the result with half the effort. Japan’s situation can be for our reference, the original production of intermediates in Japan is also very scattered, from the 1960s has been seven times to adjust, focus.

Through transformation and development, China’s dyeing and pigment intermediates industry has reached a higher level in terms of production scale, technology and equipment level, which can not only meet the needs of the development of domestic dyeing and pigment industry, but also provide more quality intermediates for foreign countries.

The raw materials required for the synthesis of intermediates are mainly obtained from the products of petroleum and coking chemical industry, most of which are benzene, naphthalene, anthraquinone compounds, and also some heterocyclic compounds, and the organic pigments prepared with heterocyclic compounds intermediates are on the rise in recent years. In addition, phenanthrene, pyridine, oxygen fluorene, quinoline, indole, carbazole, biphenyl series of compounds, these complex raw materials applied to the manufacture of dyes, then the use of synthetic raw materials will be more widespread and common.
2
The most common chemical reactions used for intermediates

Processing of raw materials into dye (color) intermediates of the most commonly used chemical reactions are as follows.
(1) sulfonation reaction
(2) Nitration reaction
(3) halogenation reaction
(4) Reduction reaction to prepare amino
(5) Diazotization reaction (often accompanied by coupling reaction)
(6) alkali fusion reaction to replace the sulfonic acid group to hydroxyl
(7) Acylation reaction
(8) Oxidation reaction
(9) condensation and carbonation reaction
(10) Aromatization reaction (mainly amino)
(11) mutual replacement reaction of hydroxyl and amino groups
(12) hydroxyl or amino hydrocarbonation reaction
According to the structure of the main aromatic ring of fine chemical intermediates, the intermediates can be divided into aliphatic system, benzene system, naphthalene system, anthraquinone system, heterocyclic system and thick ring system. Our country can produce more than 400 varieties of intermediates such as benzene, naphthalene, anthraquinone, heterocyclic and other dyeing and pigment intermediates, which can basically meet the development needs of dyeing and pigment industry.
Picture
3
The main varieties of benzene system

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-m-phenylenediamine, 3,3-dichlorobenzidine, bianisidine, p-aminobenzenesulfonic acid, o- and p-aminoanisole, DSD N-methyl-m-toluidine, N-ethyl-m-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-m-toluidine, N-methyl-hydroxyethyl-m-toluidine, N-ethyl-hydroxyethyl-m-toluidine, N-methyl-cyanoethyl-m-toluidine, N-ethyl-cyanoethyl-m-toluidine, N-ethyl-cyanoethyl-m-toluidine, N-ethyl-cyanoethyl-m-toluidine, N-ethyl-cyanoethyl-m-toluidine, N-ethyl-cyanoethyl-m-toluidine, N-ethyl-cyanoethyl-m-toluidine. m-toluidine, N-ethyl cyanoethyl m-toluidine, N-methylphenyl m-toluidine, p-toluidine, ethoxyaniline, 2-4-dimethylaniline, 4-chloro-3-aminobenzamide, 4-methyl-3-aminobenzamide, 4-methoxy-3-aminobenzanilide, 4-methoxy-3-amino-N,N-diethylbenzenesulfonamide, 2,4,5-trichloroaniline, m- and para-esters, etc.
4
Naphthalene-based intermediates main varieties

2-naphthol, H-acid, K-acid, 2,3-acid, 2,6-acid, tartaric acid, 6-nitro-1,2,4-acid oxygenate, J-acid, peri-acid, γ-acid, G-salt, R-salt, amino K-acid, 2-naphthylamine-1,5-disulfonic acid, 1-naphthol-5-sulfonic acid, 1,5-dihydroxynaphthalene, 2,6-naphthalenedicarboxylic acid, 2R-acid, etc. The main varieties of anthraquinone-based intermediates are: anthraquinone, 1-amino anthraquinone, 1,4-diamino anthraquinone, 1,5-dimethyl anthraquinone bromine, 1,5-diamino anthraquinone, 1-amino-5-benzoyl anthraquinone, 1,5-dihydroxy anthraquinone, 1,8-hydroxy anthraquinone, 1,8-dihydroxy-4,5-diamino anthraquinone, etc.
5
Heterocyclic and thick-ringed main species

Melamine, barbituric acid, 2-amino-6-nitrobenzothiazole, 2-amino-5,6-dichlorobenzothiazole, 2-amino thiazole, dehydrothio-p-toluidine bisulfonic acid, 3-cyano-4-methyl-6-hydroxy-N-ethylpyridone, 3-formylamino-4-methyl-6-hydroxy-N-ethylpyridone, 4-chloro-1,8-naphthalic anhydride, naphthalenetetracarboxylic anhydride, tetracarboxylic anhydride, etc.