Commercially Available Types and Their Application

Unsubstituted thioindigo, which is marketed as Vat Red 41, 73300, is used in rigid PVC, polystyrene, and a number of other plastics. Dissolved in its medium, the pigment affords fluorescent bluish red shades. 

88 has stimulated considerable interest throughout the paint industry. It is a suitable colorant especially for industrial coatings, including automotive (O.E.M.) finishes and automotive refinishes. Its red-violet shade is used frequently to produce opaque dark shades of red, bordeaux, and maroon, for which purpose the pig- 

Deep shades of maroon tend to form water spots in certain binder systems, especially in media which are based on acrylic resin. More or less distinctive light spots appear on the coating. The effects that cause this phenomenon remain to be elucidated. Factors such as long-term weathering at elevated temperature, U V radiation, and the presence of demineralized water probably cause reduction and solvation effects within the coating. Products are available which are much less susceptible to these agents. Rub-out effects, especially flocculation, may also present problems in various binder systems. Special-purpose grades are therefore available which are more stable to flocculation. 

88 shows good stability to organic solvents. Its fastness to overcoating is good, but not reliable at baking temperatures above 140°C. Paints containing P.R.88 are acid and alkali resistant. 

88 is also found in other systems throughout the paint industry, such as in various types of air drying systems and powder coatings. 

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