Copper phthalocyanine pigment composition and pigment composition dispersion containing same

A copper phthalocyanine pigment composition comprising a copper phthalocyanine obtainable by dry-milling a crude copper phthalocyanine in the absence of any milling aid and 1 to 20% by weight, based on the copper phthalocyanine, of a phthalocyanine derivative of formula [I] or [II]: wherein Pc is a phthalocyanine residue, M is a hydrogen atom or a metal selected from Al, Fe, Co, Ni, Cu and Zn, X is -SO2-, -CH2NHCOCH2- or -CH2-, and R1 and R2 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms or R1 and R2 together with the nitrogen atom to which they are attached form a 5- or 6-membered heterocyclic ring which may contain a further nitrogen atom or an oxygen atom, m is an integer of 1 to 5 and n is an integer of 1 to 4.