Bluishen

Bluishen is a synthetic inorganic blue pigment used in paints, coatings, and plastics. It was developed to provide a stable, bright blue color with good resistance to light and heat, and to offer an option between traditional cobalt blue and ultramarine. The name bluishen is commonly used in color science literature to describe this pigment in general terms.

Chemically, bluishen is described as a copper- and cobalt-doped silicate-like matrix in which color arises from intervalence transitions and crystal field effects. The pigment is produced by high-temperature solid-state synthesis or precipitation routes, followed by grinding to a fine powder. Particle size and milling conditions strongly influence the shade, ranging from pale azure to deep cobalt blue. Bluishen is typically insoluble in water and compatible with a wide range of binders used in artist paints and industrial coatings.

Applications include art paints, automotive finishes, and polymer coloration. It is valued for high tinting strength, good dispersibility, and excellent lightfastness compared with many organic blues. Some formulations may incorporate stabilizers to minimize darkening in acidic environments or in heat-aged cases.

History and naming: Bluishen was introduced as part of efforts to diversify blue pigments in the late 20th century. While it never achieved the market share of more established blues, it remains of interest in color science for its color mechanism and pigment performance. See also cobalt blue, ultramarine, pigment.