PY1—Hansa Yellow G

Pigment Type

organic, monoazo

Chemical Name

n/a

Chemical Formula

C₁₇H₁₆N₄O₄

Properties

This Hansa yellow is a transparent yellow. It has great brightness and tinting strength and its drying time ranges from average to slow.

Hansa Yellow makes more intense tints and cleaner secondaries than Cadmium Yellows, especially when mixed with other organic or modern colors like Phthalo Blue and Green. Because they are more transparent, they have great value as glazing colors.

Permanence

Hansa Yellow G has good permanence and lightfastness, particularly in the lighter shades.

Toxicity

Hansa Yellow pigments have no significant acute hazards, though chronic hazards have not been well studied.

History

Hansa Yellows were first made in Germany just before World War I from a series of synthetic dyestuffs called Pigment Yellow. Hansa Yellow G, introduced in 1910, was the first of these products to be commercialized. Hansa Yellow G was the standard yellow for printing inks until late in the 20th century, when stronger diarylide yellows began to replace it. It is still used a great deal in packaging, and for air drying paints.

Alternate Names

Light Fast Yellow G, Pigment Yellow G, Arylide, Arylide Yellow, Azo Yellow, Brilliant Yellow, Monoazo Yellow, Monolite Yellow, Permanent Yellow.

PW20—Mica

Pigment Type

inorganic

Chemical Name

aluminum silicate

Chemical Formula

H₂KAl₃(SiO₄)₃

Properties

An off-white pigment with complex reflective effects, mica is often used with transparent pigments to create mixed pigments with interference and pearlescent effects.

Permanence

Mica is permanent and lightfast.

Toxicity

Although it is completely non-toxic and not bioreactive, fine particles may be irritating. This is of concern primarily for those exposed occupationally to dry mica powder. Breathing mica particles may cause lung fibrosis and pneumoconiosis.

History

Mica has been used as a pigment since prehistoric times.

Alternate Names

n/a