What types of phthalocyanine blue can be used in the coatings industry?

iSuoChem Marketing Department / Edited by Jason

Phthalocyanine blue is an important dark blue pigment in the coatings industry and is mainly composed of copper phthalocyanine. Its chemical structure is quite complex, but its properties are very good. Phthalocyanine blue has several crystalline forms, three of which are used in large quantities in commercial products:

α type phthalocyanine blue (Pigment Blue 15): This phthalocyanine blue emits red light and is known for its excellent tinting strength. However, it can convert to the more stable β-form in aromatic solvents such as xylene. To prevent this from happening, manufacturers add chlorocopper phthalocyanine during the production process to form a stable α-phthalocyanine blue (Pigment Blue 15:1) in the solvent.

β type phthalocyanine blue (Pigment Blue 15:3) This type of phthalocyanine blue emits green light and is known for being very stable thermodynamically. It is very stable, but may not be as bright as the α version in some applications.

ε type Phthalocyanine blue (Pigment Blue 15:6): This phthalocyanine blue is known for its bright red light, which gives coatings a unique visual effect.

Since phthalocyanine blue pigments have a non-polar surface, it is difficult to keep them dispersed and stable in coating systems. This causes flocculation or delamination of coatings containing phthalocyanine blue during storage and use. To solve this problem, scientists treated the surface of phthalocyanine blue pigments (such as Pigment Blue 15:2) and chemically modified them. This makes them more stable and dispersible in coatings.

Download: Other pigment blue series, please download our catalog by here, Organic Pigment Catalog

In the coating industry, α-type phthalocyanine blue with a red phase is generally better than β-type phthalocyanine blue with a green phase. It has bright color, strong tinting strength, easy dispersion and good fluidity. It is also worth mentioning that the flocculation problem of coating is not only due to the pigment. It is also affected by the binder and solvent in the coating system. Therefore, coating workers need to test a large number of different combinations to find the best anti-flocculation formula for each coating system.