Brightener in the chemical structure have a cyclic conjugated system

Brightener (brightener / Optical whitener) is a type of fabric and can enhance the whiteness of paper and other organic compounds. Also known as optical brighteners, fluorescent brighteners . Fabric, etc. are often contained as impurities, and yellow colors , in the lead stabilizer  past are used for bleaching chemical bleaching methods , add brighteners used in the product approach. Its role is to absorb the products of invisible ultraviolet radiation into fluorescence radiation purple blue , yellow with the original two colors, a white light radiation , improve the whiteness in the Glycerol monostearate  sunlight . Brightener has been widely used in the textile , paper, detergent , soap , rubber, plastics, pigments and paints and so on.
Brightener in the chemical structure have a cyclic conjugated system , for example: derivatives of stilbene , pyrazoline phenyl derivatives, benzimidazole derivatives , phenyl pyrazole derivatives , coumarin derivatives , and naphthalimide derivatives. Stilbene derivatives which yield the largest , such as 4,4 ' - bis ( 4,6 - diphenyl amine triazin -2 - amino ) stilbene -2,2' - disulfonic acid sodium salt is a the wider use of optical brighteners, whitening tradename TA. Such brighteners have  black iron oxide been widely used in papermaking, textile , detergent and soap industries. Brightener AD is phenyl derivative of pyrazoline , scientific name 1 - ( methylsulfonyl ) -3 - (p- chlorophenyl ) pyrazoline, mainly for spinning of acrylic fiber , textiles and plastics products for the production. 4 - methyl-7 - dimethylamine coumarin naphthalene neighbors belong oxa ketones can be used for wool fabric , nylon fabric, soaps and detergents and other products.
The largest class of fluorescent whitening agent VBL, CXT and paper liquid whitener . Generally divided into two categories brighteners , and the other is water insoluble brightener . The former can be used for paper, paint , detergent, cotton fabric whitener . The latter can be used for chemical fiber, plastics and other whitening.