Organic Optical Brighteners

Only a few classes of organic compounds are suitable as brighteners for polymers. These include  

To be effective, the optical brightener must dissolve in the polymer. T5q3ical addition levels of organic brighteners are in the range of 25-250 ppm. 

Optical brighteners are used in a wide variety of polymers (14-16). There are t) es that have the FDA approval for a variety of food-contact applications. 

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Organic Reactions. Nitric acid is used extensively ia iadustry to nitrate aHphatic and aromatic compounds (21). In many iastances nitration requires the use of sulfuric acid as a dehydrating agent or catalyst the extent of nitration achieved depends on the concentration of nitric and sulfuric acids used. This is of iadustrial importance ia the manufacture of nitrobenzene and dinitrotoluene, which are iatermediates ia the manufacture of polyurethanes. Trinitrotoluene (TNT) is an explosive. Various isomers of mononitrotoluene are used to make optical brighteners, herbicides (qv), and iasecticides. Such nitrations are generally attributed to the presence of the nitronium ion, NO2, the concentration of which iacreases with acid strength (see Nitration). 

A collection of UV spectra of plasticisers, fluorescent whitening agents (optical brighteners), UV absorbers, as well as of phenolic and aminic antioxidants was published by Hummel and Scholl [21]. UV absorbance data for isolated chromophores are listed elsewhere [22]. A general UV atlas of organic compounds is available [23]. 

Fluorescence is much more widely used for analysis than phosphorescence. Yet, the use of fluorescent detectors is limited to the restricted set of additives with fluorescent properties. Fluorescence detection is highly recommended for food analysis (e.g. vitamins), bioscience applications, and environmental analysis. As to poly-mer/additive analysis fluorescence and phosphorescence analysis of UV absorbers, optical brighteners, phenolic and aromatic amine antioxidants are most recurrent [25] with an extensive listing for 29 UVAs and AOs in an organic solvent medium at r.t. and 77 K by Kirkbright et al. [149]. 

Uses Solvent for waxes, casein, dyes, and resins manufacture of rubber additives, various pharmaceuticals, paper chemicals, plasticizers, corrosion inhibitors, emulsifiers, pesticides solvent optical brightener for detergents hair conditioners additive to boiler water preservation of book paper ingredient in various automotive products including brake cleaners and waxes organic synthesis. 

The major uses of or /zo-toluidine and its hydrochloride salt are as intermediates in the manufacture of over 90 dyes and pigments, including acid-fast dyestuffs, optical brighteners, synthetic rubber and rubber chemicals, pharmaceuticals and pesticides (lARC, 1982 Bayer Organic Chemicals, 1995 American Conference of Governmental Industrial Hygienists, 1999). 

Morpholine is a synthetic organic liquid used mainly as an intermediate in the production of rubber chemicals and optical brighteners, as a corrosion inhibitor in steam condensate systems, as an ingredient in waxes and polishes and as a component of protective coatings on fresh fruits and vegetables. Occupational exposure may occur during the production of morpholine and in its various uses, but data on exposure levels are sparse. It has been detected in samples of foodstuffs and beverages (lARC, 1989). 

Optical brighteners are also used to enhance the whiteness of various inorganic and organic substrates, such as tripolyphosphates, carbonates, and photographic papers [152-154],... 

Use Rubber accelerator, solvent, additive to boiler water, waxes and polishes, optical brightener for detergents, corrosion inhibitor, preservation of book paper, organic intermediate (catalyst, antioxidants, pharmaceuticals, bactericides, etc.). 

Classification. Extenders are mainly natural minerals that are converted into a usable form by working natural deposits, separating secondary constituents, and comminution (micronization). Synthetic products such as precipitated carbonates [e.g., calcium carbonicum praecipitatum (ccp), precipitated sulfates (e.g., blanc fixe), precipitated and pyrogenic silica, and silicates are used for optical brightening. Synthetic fibers (generally organic) are used for reinforcement. The classification of extenders used in surface coatings is summarized in Table 4.1. 

Uses Organic intermediate emulsifier in anionic coatings, wax formulations emulsifier intermediate for water treating chemicals, agric. chemicals neutralizer in preboiler system optical brightener intermediate Manuf./Distrib. Aldrich Atofina BASF Fluka Huntsman... 

Approximately 800,000 tpa of organic dyestuffs (dyes, pigments and optical brighteners) are produced worldwide. Since the beginning of the industrial production of organic dyestuffs, aromatics have been the dominant raw materials for this group of products. 

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