Brighteners are a class of organic compounds that can improve the whiteness of fiber fabrics and paper. Also known as optical brightener, fluorescent whitening agent. Fabrics, etc. are often yellow due to the inclusion of colored impurities. In the past, chemical bleaching was used to decolorize them, and whitening agents were added to the products.

The role of brighteners

The function of the brightener is to convert the invisible ultraviolet radiation absorbed by the product into violet-blue fluorescent radiation, which complements the original yellow light radiation into white light and improves the whiteness of the product under sunlight. Brighteners have been widely used in textiles, paper, washing powder, soap, rubber, plastics, pigments and paints.

As an important fine chemical product, fluorescent whitening agents have a wide range of industrial applications and good market prospects. Many scientists at home and abroad are working on the research of fluorescent whitening agents. The main research directions are Develop fluorescent whitening agents with strong practicability, such as fluorescence fastness, easy availability of raw materials, simple synthesis, and no pollution.

Application of brightener

Brighteners all have cyclic conjugated systems in chemical structure, such as: stilbene derivatives, phenylpyrazoline derivatives, benzimidazole derivatives, phenylpyrazole derivatives, coumarin derivatives, and naphthalimide derivatives, etc. Among them, the stilbene derivatives have the largest yield, such as 4,4'-bis(4,6-diphenylaminotriazinyl-2-amino) stilbene-2,2'-disulfonic acid sodium salt is a Widely used brightener, the trade name is brightener TA. Such brighteners have been widely used in industries such as papermaking, textiles, laundry detergents and soaps. Brightener AD is a derivative of phenylpyrazoline, scientific name 1-(p-methanesulfonylphenyl)-3-(p-chlorophenyl)pyrazoline, mainly used for acrylic fiber spinning, textiles and plastics product in production. 4-Methyl-7-dimethylaminocoumarin belongs to the oxa-naphthalone compound and can be used in wool fabrics, nylon fabrics, soaps and detergents and other products.

The largest type of fluorescent whitening agents in China are VBL, CXT and liquid whitening agents for papermaking. Generally, whitening agents are divided into two categories, one is water-soluble whitening agents, and the other is water-insoluble whitening agents. The former can be used as a whitening agent for paper, paint, washing powder, and cotton fabrics. The latter can be used to whiten chemical fibers, plastics, etc.

Although my country's fluorescent whitening agent has developed rapidly, compared with the international market, the proportion of fluorescent whitening agent in the dye industry is relatively low, and the variety is relatively small. With the development of my country's economy and the improvement of living standards, the demand for fluorescent whitening agents will also keep pace with each day, and the output, varieties and dosage forms will have great development. While increasing varieties in China, special attention should be paid to The development and research of mixed and compounded efficiency products, liquid commodities, and low-salt environmental protection products will further improve product quality, expand exports and strengthen competitiveness in the international market on the premise of meeting domestic needs.