Phthalocyanine commercially available pigment

In the presence of a solvent, the crude pigment generally evolves in much purer form than if it is prepared by baking. Higher degrees of purity, i.e., up to 98%, are achieved by additional alkaline and/or acidic treatment. Commercially available types of crude Copper Phthalocyanine Blue typically contain more than 90% pure pigment. This preliminary product is also commonly supplied to and finished by companies who do not manufacture crude pigment themselves. 

The a- and (i-types of Copper Phthalocyanine Blue reign supreme among commercially available phthalocyanine pigments. There is also an increasing amount of interest in the phase-stabilized form of the a-crystal modification. Both modifications are also supplied as flocculation resistant types. 

Table 27 Commercially available copper phthalocyanine pigments (if not other mentioned).

Copper phthalocyanine is available as two major commercial forms, the alpha and the beta crystal. Other crystal variations such as the epsilon crystal PB 15 6 are available commercially but on a very limited basis. The alpha crystal is described as Cl pigment blue 15 1 and 15 2 and is a clean, bright-red-shade blue. The beta crystal is described as Cl pigment blue 15 3 and 15 4 and is a clean green-shade blue. The beta form is the most stable crystal form and readily resists crystallization. The alpha form, conversely, is the least stable, or meta, form and readily converts to the more stable, green-shade beta crystal. As such, the alpha crystal requires special, proprietary treatments to produce a red-shade product offering stability to both crystallization and flocculation. 

The structure shown in Figure 1 is the parent compound of the phthalocyanine pigments. The unsubstituted (no halogen atoms) ring system yields a blue pigment which is available in two crystal forms, alpha (red shade) and beta (green shade). The commercial pigments usually have some Cl substitution, which provide additional heat stability. 

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