Name: Ultramarine Blue No. 462
Brand: Coatingsink
SKU: ultramarine-blue-462
Availability: InStock

Question 1

Why is ultramarine blue used as a whitening agent in paints and plastics?

Accepted Answer

Ultramarine blue absorbs yellow wavelengths of visible light, counteracting the slight yellowness inherent in white TiO2-based paints and polyolefin plastics. By adding 0.05–0.3% ultramarine blue, formulators achieve a perceptibly brighter, cooler-white appearance without increasing TiO2 loading. This optical whitening effect is widely used in white architectural paints, PVC pipe compounds, and polyethylene film to improve visual brightness at low cost.

Question 2

What are the chemical resistance limitations of ultramarine blue pigments?

Accepted Answer

Ultramarine blue is sensitive to acids. Even weak acids (pH <5) cause decomposition of the polysulfide chromophore, resulting in permanent colour loss and release of hydrogen sulfide gas. It should not be used in acid-catalysed coating systems, low-pH plasters, or formulations containing acidic monomers. It is stable in neutral to mildly alkaline environments (pH 6–12), making it well suited for lime-based renders, cement-based coatings, and latex paints.

Lightfastness	8
Oil Absorption	35–45 g/100g
pH (10% slurry)	9.5–10.5
Particle Size (d50)	2–4 µm
Hiding Power (at 50µm)	medium

Ultramarine Blue No. 462

Specifications

FAQ

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