Phthalocyanine Green G

Phthalo Green

— Colour coordinates —

Hex triplet #123524
RGBB (r, g, b) (18, 53, 36)
HSV (h, s, v) (151°, 66%, 21%)
Source The Mother of All HTML Colo(u)r Charts
B: Normalized to [0–255] (byte)

Phthalocyanine Green G, also called phthalo green, Pigment Green 7, Copper Phthalocyanine Green, C.I. Pigment Green 42, Non-flocculating Green G, Polychloro copper phthalocyanine, or C.I. 74260, is a synthetic green pigment from the group of phthalocyanine dyes, a complex of copper(II) with chlorinated phthalocyanine. It is a very soft green powder insoluble in water.

Its CAS numbers are [1328-45-6] and [1328-53-6] depending on the extent of chlorine substitition: chemical formula ranges from C32H3Cl13CuN8 to C32HCl15CuN8. It is a bright, high intensity colour used in oil and acrylic based artist's paints, and in other applications.

Contents

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.

Related compounds

Copper phthalocyanine green 36 is a variant where some of the chlorine atoms are replaced with bromine.[1]

Toxicity and Hazards

There is evidence that exposure to phalocyanines can cause serious birth defects in developing embryos.[2]

See also

References

  1. ^ Phthalo Green: How Can You Tell If It's Always the Same? 1/7/2003 , Dr. Richard M. Podhajny, Ph.D. , pffc-online.com
  2. ^ "Sulphonated phthalocyanine induced caudal malformative syndrome in the chick embryo." (Abstract), Sandor S, Prelipceanu O, and Checiu I., U.S. National Library of Medicine National Institutes of Health