Phthalocyanine Green :
Properties, chemistry and production
Phthalocyanine green is a phthalocyanine blue pigment where most of the hydrogen atoms are replaced with chlorine. The strongly electronegative chlorine atoms influence the distribution of the electrons in the phthalocyanine structure, shifting its absorption spectrum. It is made by chlorination of the phthalocyanine blue as a melt of sodium chloride and aluminium chloride, to which chlorine is introduced at elevated temperature.
The phthalo green molecules are highly stable. They are resistant to alkali, acids, solvents, heat, and ultraviolet radiation.
Uses
Due to its stability, phthalo green is used in inks, coatings, and many plastics. In application it is transparent. The pigment is insoluble and has no tendency to migrate in the material. It is a standard pigment used in printing ink and packaging industry. It is also allowed in all cosmetics except those used around the eyes, and is used in some tattoos.