Process for the production of phthalocyanine pigment

A process for the production of a phthalocyanine pigment which comprises the following steps (a), (b) and (c),

• (a) reacting phthalic anhydride or its derivative, urea or its derivative and a catalyst in an aromatic hydrocarbon solvent to synthesize a phthalocyanine crude,
• (b) wet-milling a slurry of the synthesized phthalocyanine crude in the presence of a particulate milling medium having a diameter of 0.1 to 0.3 mm without removing the aromatic hydrocarbon solvent, and
• (c) removing the aromatic hydrocarbon solvent from the slurry of the milled product, purifying the milled product and drying the milled product with a spray type dryer,
• wherein at least one phthalocyanine derivative of the following formulae (1) to (3) is added after the phthalocyanine crude is synthesized in step (a) or when the phthalocyanine crude is wet-milled in step (b),
• MePc(SO.sub.1.sup.-+ NR.sup.1 R.sup.2 R.sup.3 R.sup.4).sub.n( 1)
• wherein MePc is a metal-free or metal-containing phthalocyanine residue on which a halogen atom may be substituted, each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a polyoxyalkylene group, and n is an integer of from 1 to 4,
• MePc›X--Y--Z--N(R.sup.5)R.sup.6 !.sub.k ( 2)
• wherein MePc is as defined above, X is a direct bond or a divalent binding group of a chemically rational combination consisting of 2 to 15 atoms selected from S, C, N, O and H atoms, Y is a direct bond, a --N(R.sup.7)-- in which R.sup.7 is an alkyl group having 1 to 18 carbon atoms or Z--N(R.sup.5)R.sup.6, or --O--, Z is an alkylene group having 1 to 6 carbon atoms, each of R.sup.5 and R.sup.6 is independently an alkyl group having 1 to 18 carbon atoms or a substituted alkyl group having 1 to 18 carbon atoms, or R.sup.5 and R.sup.6 together with the nitrogen atom to which they are attached form a 5- or 6-membered heterocyclic ring which may contain N, O or S and which may have a substituent, and k is an integer of from 1 to 3, ##STR8## wherein MePc is as defined above, A is a halogen atom or a nitro, amino, sulfone, carboxyl or alkyl group, p is an integer of 0 to 4 and m is an integer of 1 to 4.