Blockx Soft Pastel - Capucine Yellow 121

Pigment Information

This color contains the following pigments:

PY83-Diarylide Yellow 83

PR254-Pyrrole Red

Pigment Name

PY83-Diarylide Yellow 83

Pigment Type

organic, disazo

Chemical Formula

C36H32Cl4N6O8

Properties

Diarylide Yellow is a semi-opaque, moderately staining, intense deep reddish yellow pigment with good tinting strength.

Permanence

Diarylide Yellow 83 has very good lightfastness and permanence. However, it can fade in tints, so some artists do not consider it suitable as an artists' color. Many other diarylide yellow pigments are reported to have fair to poor lightfastness, and some are completely fugitive. Diarylide Yellow 83 is reputed to be one of the most permanent of the entire group.

Toxicity

Diarylide Yellow has no significant acute hazards, but chronic hazards have not been well studied.

History

Diarylide Yellow comes from a family of azo pigments called Diarylide. These yellow hued pigments were developed around 1940 and are very important in printing inks.

Pigment Name

PR254-Pyrrole Red

Pigment Type

organic, aminoketone

Chemical Name

Bis-(p-chrolopheny)-1. 4-diketopyrrolo(3. 4-c)pyrrole

Properties

Pyrrole Red is opaque and has strong covering power. According to manufacturer Ciba, which uses the trade name Irgazin Red, it is a “clean, highly saturated mid shade red with high temperature resistance, excellent color strength, outstanding chemical, solvent and bleed resistance, and good weatherfastness.”

Permanence

Pyrrole Red is considered to have excellent lightfastness among organic pigments in its class. Tests in industrial applications have given it scores of 7-8 on the Blue Wool Scale.

Toxicity

According to the Australian government's Ministry on Health and Aging, "The notified chemical exhibited low oral and dermal toxicity in rats, did not exhibit toxic effects when administered orally to rats for 28 days, was not a skin irritant in rabbi

History

Pyrrole Red, used as an automotive paint and as a colorant in plastics, was developed as one of a range of pigments to replace lead based pigments. In art materials, it is often used as a synthetic and lightfast replacement for carmine, a laked pigment that was originally produced from the body of the cochineal insect. It is also used to replace the older naphthol reds, organic red pigments that are sometimes only marginally lightfast and weatherfast.