Both ultramarine blue and phthalocyanine blue are widely used blue pigments, but they have distinct differences in shade, properties, and application suitability. Understanding these differences helps manufacturers make informed pigment selection decisions.
Ultramarine blue (PB29) provides a reddish-blue shade with a warm, sky-blue appearance, while phthalocyanine blue (PB15) is a greenish blue with much higher tinting strength. The choice of shade depends on the color target of the final product.
In terms of heat stability, both pigments perform well. However, ultramarine blue is more thermally stable and is less likely to undergo shade shifts at high processing temperatures in plastics. Phthalocyanine blue can sometimes cause warpage in crystalline polymers.
Ultramarine blue is non-toxic and considered safe for skin-contact applications including cosmetics. Phthalocyanine blue is generally considered safe but may not be approved for the same cosmetic applications depending on regional regulations.
Cost is another consideration: ultramarine blue is generally less expensive than phthalocyanine blue, making it a cost-effective choice for applications where either pigment would be technically acceptable. SKU Pigments offers both competitively priced ultramarine options.