A series of organic color pigments used in printing inks. Most of the Phthalocyanine Blues mentioned below are categorized as CI Pigment Blue 15, each one differing from the others in one respect or another, and are modifications of PB 15.
Phthalocyanine Blue (Alpha Form) is a strong red shade of blue, and possesses high lightfastness and resistance to acids, alkalis, heat, waxes, oils, solvents, and soaps. It is the least used of the PB 15 pigments, but is occasionally used in newsinks. This variety is a solvent-unstable form of PB 15. ('CI Pigment Blue 15 No. 74160...)
Phthalocyanine Blue (Alpha, Solvent-Stable) is a bright red shade of blue, and possesses high lightfastness and resistance to acids, alkalis, heat, waxes, oils, solvents, and soaps. It is the most commonly used of the PB 15 pigments, accounting for 25% of the PB 15 use. It is more resistant to heat and more solvent-stable than the alpha form above.
Also known as Phthalo Blue NC Alpha ('CI Pigment Blue 15:1 No. 74160 or 74250'.)
Phthalocyanine Blue NCNF (Alpha Form, Solvent-Stable, Non-Flocculating) is a bright red shade of blue, and possesses many of the same properties as PB 15:1, differing in that the pigment particles have been treated to prevent flocculation, or undesirable clumping together of the particles. It is more expensive than PB 15 or 15:1, but accounts for about 5% of PB 15 use.
('CI Pigment Blue 15:2 No. 74160 or 74250'.)
Phthalocyanine Blue NC (Beta Form, Solvent-Stable) is a bright green shade of blue, and possesses high lightfastness and high resistance to acids, alkalis, heat, waxes, oils, solvents, and soaps. It is transparent, solvent-stable, has strong tinting strength, but is weaker than alpha forms of Phthalocyanine Blue. It is the most commonly used cyan in process color printing, as it is usable in every type of ink and printing process.
('CI Pigment Blue 15:3 No. 74160'.)
Phthalocyanine Blue B NCNF is a bright green shade of blue possessing all the high resistance properties of the other PB 15 pigments. This version, like PB 15:2, has been treated to prevent flocculation of the pigment particles. It is used primarily in liquid inks, and is also useful as a process color cyan.
('CI Pigment Blue 15:4 No. 74160'.)
Phthalocyanine Blue (Epsilon Form) is a strong red shade of blue, and possesses all the high resistance properties of the Phthalo Blue series. It is the only solvent-stable reddish shade in the series, and finds most of its use in liquid-ink applications.
('CI Pigment Blue 15:6 No. 74160'.)
Phthalocyanine Blue (Copper Free) is the greenest shade of Phthalo Blue, and possesses the high resistance properties of other Phthalo Blue pigments, although it tends to be less heat resistant than other versions. (Its primary difference, as its name indicates, is the lack of copper in its molecular structure.) It is more expensive than other Phthalo Blues, and is limited to use in applications requiring a metal-free ink.
('CI Pigment Blue 16 No. 74100'.)
(See also Organic Color Pigments.)