PR 166 – azo condensation red

Manufacturer/ product code:  Kremer / 23202
Chemical Description: azo condensation
Color: red
Color Index: PR 166
Date:  —

PR 166 – Azo Condensation Red is a synthetic organic pigment belonging to the azo condensation class, developed to provide high-performance red hues with improved durability compared to earlier mono- and disazo pigments. Introduced in the second half of the 20th century, PR 166 reflects advances in pigment chemistry aimed at combining strong coloristic properties with enhanced resistance to light, heat, and chemicals.

In appearance, PR 166 exhibits a deep, warm red, often leaning toward a scarlet or slightly orange-red hue depending on particle size and formulation. It is typically semi-opaque to opaque, offering excellent coverage and strong tinting strength. This makes it especially suitable for solid color applications, where uniformity and saturation are required. In mixtures, PR 166 produces clean oranges with yellow pigments and rich, earthy browns when combined with blues or blacks, though it is less favored for transparent glazing compared to quinacridone reds.

From a technical standpoint, azo condensation pigments are known for their robust molecular structure, which imparts superior lightfastness and thermal stability relative to many conventional azo reds. As a result, PR 166 is widely used in industrial applications such as automotive coatings, plastics, and printing inks. In artists’ materials, it is valued for its reliability and strength, representing a bridge between cost-effective azo pigments and higher-end organic reds in terms of performance and permanence.