| abstract |
A single stage process for the production of copper phthalocyanine pigment compositions having x-ray diffraction spectra corresponding to the form of pure, or substantially pure ε-crystal modification of copper phthalocyanine comprising reacting, at an elevated temperature and in an organic solvent, an organic compound capable of forming the phthalocyanine ring system, a copper compound capable of providing the copper atom of the phthalocyanine molecule, a reaction catalyst, and a nitrogen source, in the presence of, as crystal form modifier, a compound of the formula: ##STR1## where Pc represents a copper phthalocyanine residue, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are the same or different and each is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl, aralkyl, alkaryl, cycloalkaryl or dehydroabietyl group, the alkyl and cycloalkyl groups being optionally unsaturated and/or interrupted by heteroatoms, M represents hydrogen or an alkali metal atom and x, y and z are each in the range of from 0 to 4 with the proviso that the sum of x, y and z is within the range of from 1 to 4. Very red shade copper phthalocyanine pigment compositions of the advantageous ε-modification can be produced in a single stage without the use of high shear forces. |