Лако-красочные материалы — производство

A number of carbonyl dyes are characterised by strong fluorescence. One of the most important groups of fluorescent brightening agents and dyes is based on the coumarin ring system. The important fluorescent coumarin derivatives almost invariably contain an electron-releasing substituent in the 7-position, which is most commonly a dialkylamino group but may be hydroxy or methoxy. The earliest and still the most widely-used coumarin dyes contain a benzimidazolyl, 63a, benzoxazolyl, 63b, or benzothiazolyl, 63c, group as the acceptor in the 3-position. C. I. Disperse Yellow 232, 63d, for example, dyes polyester to give a brilliant fluorescent greenish-yellow hue with good fastness to light, sublimation and washing. Other important types of fluorescent carbonyl dyes include the aminonaphthalimides, such as C. I. Disperse Yellow 11, 64, and some sterically hindered perylenes which are considered in the next section. Fluorescent dyes and pigments find a wide range of uses in textiles, plastics, paint and printing inks where high visual impact is desirable, such as advertising and safety applications. They are also used in the detection of flaws in engineered articles, solar collector systems, dye lasers and a host of analytical and biological applications.