Fluorescence whitening agents

Table 1. Symmetrical Stilbene Derivatives used as Fluorescent Whitening Agents...

Other Heterocyclic Systems. Naphthalimides (15), where R = —NHCOR, are derivatives of 4-anTinonaphthalimide (69) and are used in plastics. The alkoxynaphthalimides (15, R = OCH ) (70,71) are of particular interest as fluorescent whitening agents. 

Initially, fluorescent whitening agents (FWAs) were used exclusively in textile finishing the detergent and paper industries followed thereafter. These products are also used in fiber spinning masses, plastics, and paints. 

Table 5. Fluorescent Whitening Agents in the Detergent Industry...

Table 6. Fluorescent Whitening Agents Used in the Synthetic Fibers and Plastics Industries...

Fluorescent Whitening Agents," in F. Coulston and F. Korte, eds.. Environmental Quality and Safety Suppl. Vol. 4, Georg Thieme Vedag, Stuttgart, and Academic Press, Inc., New York, 1975. 

Blueing agents, which are dyes, provide another approach to maintaining fabric whiteness by a mechanism in which a yellow cast of washed fabrics is covered by the blue dye. Since this approach reduces reflectance, it is less desirable than the use of fluorescent whitening agents that increase reflectance. 

Dye Intermedia.tes, Dye intermediates are defined as those precursors to colorants that are manufactured within the dyes industry, and they are neady always colodess. Colored precursors are conveniendy termed color bases. As distinct from primaries they are only rarely manufactured in single-product units because of the comparatively low tonnages requited. Fluorescent brightening agents (FBAs) are neither intermediates nor tme colorants. Basic manufacturing processes for FBAs are described in Reference 18 (see Fluorescent whitening agents). 

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