Acid Violet lightfastness

If suitable amino azo compounds are coupled to iV-phenylamino-5-naphthol-7-sulfonic acid, violet, moderately lightfast paper dyes with good brilliance are obtained, e.g., C.I. Direct Violet 51, 27855 [6227-10-7] (15). 

Figure 6. Lightfastness behavior af Acid Violet 19 as exposed to an Atlas...

Commercial interest inP.V.5 l, Constitution No. 58055 1,has declined considerably. The pigment continues to be used in industrial paints, especially throughout the USA. Its full shade is a brilliant, deep bluish maroon. In white reductions, the pigment produces clean, reddish violet shades. It lacks tinctorial strength and the coatings are fast to neither acid nor alkali. P.V.5 1 is also not very lightfast, which practically precludes its use in products for exterior application, particularly in reduced shades. 

Acylation of 1-amino- or 1,5-diaminoanthraquinones yields yellow vat dyes and affords red to ruby colored dyes when 1,4-diaminoanthraquinones are used. Use of 4,8-diamino-l,5-dihydroxy-anthraquinones gives violet to blue dyes. The relatively low lightfastness of the yellow acylaminoanthraquinones may be improved greatly by using azodiphenyl-4,4 -dicarboxv 1 ic acid. Acylaminoanthraquinones are relatively sensitive to atmospheric conditions. 

Uses Fluorescent brightener for aq. inks and coatings Features Compat. with most waterborne and water-reducible inks and coatings suitable for applies, where extended lightfastness is required fluoresces blue-violet color when irradiated with UV light good stability to acids and alkalis... 

Uses Pigment with mod. brilliance for papers (tinting of sized, acid, alkaline, coatings), suitable for tinting and deeper shades Features Violet partially bleachable in hypochlorite exc. lightfastness ... 

Chem. Descrip. Pigment violet 19 CAS 1047-16-1 EINECS/ELINCS 213-879-2 Uses Pigment for beater applic. to acid-sized papers, esp. where high lightfastness is required, for neutral or alkaline-sized papers where cationic retention mechanism is used, and for coatings and deco printing inks... 

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