Patent ID: 8168359

Claim:
Nano-sized phthalocyanine pigment particles, comprising: a phthalocyanine chromogen structure as a main component, and a substituted soluble metal-phthalocyanine dye as a minor component that non-covalently bonds with the phthalocyanine chromogen structure, molecules of the substituted soluble metal-phthalocyanine dye being intercalated between layers of the phthalocyanine chromogen structure, wherein the substituted soluble metal-phthalocyanine dye is where: M is a metal or group of metals and atoms capable of bonding to a central cavity of the phthalocyanine molecule; and each R independently represents H or a sterically bulky substituent, provided that at least one R is other than hydrogen, and the sterically bulky substituent is a wax-like aliphatic group or an alkylaryl or arylalkyl group, where: the alkylaryl or arylalkyl group comprises a C═N or C═S double bond, or the alkylaryl or arylalkyl group is fully saturated consisting of a hydrocarbon group.