Introduction of Brightener

Sep 26, 2021

Brighteners are organic compounds that can improve the whiteness of fiber fabrics and paper. Also known as optical brightener and fluorescent brightener. Fabrics are often yellow because they contain colored impurities. In the past, chemical bleaching methods were used to decolorize, and brighteners were added to the products.

The function of the brightener is to convert the invisible ultraviolet radiation absorbed by the product into purple-blue fluorescent radiation, which complements the original yellow radiation to become white light, and improves the whiteness of the product under sunlight. Brighteners have been widely used in textiles, papermaking, washing powder, soap, rubber, plastics, pigments and paints.
As an important fine chemical product, fluorescent whitening agent has a wide range of industrial applications and good market prospects. At present, many scientists at home and abroad are committed to the research work of fluorescent whitening agent. The main research direction is the development of fluorescent whitening agent. Fading, easy to obtain raw materials, simple synthesis, no pollution and other practical fluorescent brighteners.

application:The brightener has a cyclic conjugated system in the chemical structure, such as: stilbene derivatives, phenylpyrazoline derivatives, benzimidazole derivatives, phenylpyrazole derivatives, coumarin derivatives, And naphthalimide derivatives and so on. Among them, the production of stilbene derivatives is the largest. For example, 4,4'-bis(4,6-diphenylaminotriazinyl-2-amino)stilbene-2,2'-disulfonate sodium salt is a kind of A brightener with a wide range of uses, the trade name is brightener TA. Such brighteners have been widely used in papermaking, textiles, washing powder and soap industries. Brightener AD is a derivative of phenylpyrazoline, the scientific name is 1-(p-methylsulfonylphenyl)-3-(p-chlorophenyl)pyrazoline, mainly used in acrylic fiber spinning, textiles and plastics The product is in production. 4-Methyl-7-dimethylamine coumarin belongs to the oxaphthalone compound and can be used in products such as wool fabrics, nylon fabrics, soaps and detergents.

The largest domestic fluorescent brighteners are VBL, CXT and liquid brighteners for papermaking. Generally, brighteners are divided into two categories, one is water-soluble

Whitening agent, another type is water-insoluble whitening agent. The former can be used as a brightener for paper, paint, washing powder and cotton fabrics. The latter can be used for whitening of chemical fibers and plastics.
Although my country's fluorescent whitening agent has developed rapidly, compared with the international market, the output of fluorescent whitening agent accounts for a low proportion of the dye industry and there are fewer varieties. With the development of my country's economy and the improvement of living standards, the demand for fluorescent whitening agents will also increase day by day, and there will be great developments in output, varieties, and formulations. While increasing varieties in China, special attention should be paid The development and research of mixed and compound synergistic products, liquid products, and low-salt environmentally friendly products will further improve product quality, expand exports and strengthen competitiveness in the international market on the premise of meeting domestic needs.
Classification
According to the chemical structure, it can be divided into five categories:
①Stilbene type, used in cotton fiber and some synthetic fibers, papermaking, soap making and other industries, with blue fluorescence;
②Coumarin type, with the basic structure of coumarone, used in celluloid, PVC, etc., with strong blue fluorescence;
③Pyrazoline type, used for wool, polyamide, acrylic and other fibers, with green fluorescent color;
④ Benzooxynitride type, used for acrylic and other fibers and polyvinyl chloride, polystyrene and other plastics, with red fluorescence;
⑤Phthalimide type, used for polyester, acrylic, nylon and other fibers, with blue fluorescence.

It is often divided into:
① Fluorescent brightener for detergent; ② Fluorescent brightener for textiles; ③ Fluorescent brightener for papermaking; ④ Fluorescent brightener for plastics and synthetic materials; ⑤ Fluorescent brightener for other purposes.