A Brief Analysis of the Development and Application of Environmentally Friendly Dye Intermediates

A Brief Analysis of the Development and Application of Environmentally Friendly Dye Intermediates
The development of the use of intermediates is actually multifaceted. A certain type of intermediate is called an environmentally friendly dye intermediate when used in environmentally friendly dyes, while it is also called a pesticide or pharmaceutical intermediate when used in pesticides and pharmaceuticals. Intermediates should be considered as a branch of the fine chemical industry as a whole, and should not be rigidly divided into environmentally friendly dye intermediates, pesticide intermediates, and pharmaceutical intermediates according to the industry. This will reduce the scope of use of some intermediates and affect their development.
The characteristic of fine chemical intermediate research is a wide variety, with the exception of a few varieties that have a particularly large production scale, most of which are not very large in tonnage. However, the preparation process is often complex, involving many unit reactions and separation processes, and a considerable amount of "three wastes" generated during production need to be properly treated. Therefore, it is necessary to conduct process research on serialized products and reasonably organize the production of intermediates in order to achieve good economies of scale.
From the perspective of foreign countries, the research and production of intermediates tend to be appropriately concentrated to achieve serial production. A set of production equipment can produce several to more than ten varieties of intermediates. This research and production is relatively easy to implement through overall development and new technologies, and will achieve twice the result with half the effort. The situation in Japan can provide us with reference. The production of intermediates in Japan was also very dispersed, and has undergone seven adjustments and concentrations since the 1960s.
Through transformation and development, China's dyeing and pigment intermediate industry has reached a higher level in terms of production scale, technology, equipment level, etc. It can not only meet the needs of the domestic dyeing and pigment industry development, but also provide more high-quality intermediate products for foreign countries.
The raw materials required for the synthesis of intermediates are mainly obtained from products in the petroleum and coking chemical industries. The vast majority are benzene based, naphthalene based, and anthraquinone based compounds, as well as some heterocyclic compounds. In recent years, the use of heterocyclic compounds as intermediates to prepare organic pigments has shown an upward trend. In addition, the use of complex raw materials such as phenanthrene, pyridine, oxyfluorene, quinoline, indole, carbazole, and biphenyl in the production of environmentally friendly dyes will become more widespread and widespread.