This color contains the following pigments:
organic, naphthol AS
Pigment PR170 is a bright deep red with bluish undertones. It has an average drying time. It has two crystaline forms that differ significantly in opacity. The more transparent form (F5RK) tends to be more bluish and is less lightfast.
The lightfastness and weatherfastness of Pigment PR170 varies, depending on the application and the crystaline form. The opaque form (F3RK) has very good lightfastness, and is more weather resistant. The transparent form (F5RK) has lightfastness that is considered acceptable in pure applications, but it fades more in tints. Neither form is considered suitable for exterior use.
Naphthol Reds are not considered toxic. They may cause eye, skin, or respiratory irritation. Contact with dry pigment should be avoided.
Naphthol pigments are actually dyes that are "laked" to form pigments. First developed by the German chemical company Hoechst A.G. before World War I, their use in artist paints began in the 1920s. Pigment Red PR170 is a Naphthol AS pigment, chemically related to the diarylide yellow pigments. The Naphthol AS pigments comprise a range of reds. They are used in plastics, textiles, and printing inks.
beta-oxynaphthoic acid lake, manganese salt
Permanent Red is a common name used for the manganese salt of beta-oxynaphthoic acid (BONA) lake pigment PR:48. It is more blue than other shades of PR:48, with the exception of PR48:2. BONA pigment lakes have high tinting strength.
Beta-oxynaphthoic acid (BONA) lake pigments are more lightfast than their beta-naphthol counterparts. Although their lightfastness makes them the pigment of choice in many applications, they may shift slightly in color or lose intensity under some conditions. Pigment PR48:4 is considered more lightfast and durable than other PR48 salts.
Beta-oxynaphthoic acid may have been synthesized as early as 1887. Commerical use of BONA lake pigments began in the 20th century. Pigment PR48:4 is used in packaging and plastics.