The crystal phase adjustment and the after treatment of Copper Phthal-ocyanine pigments were studied experimentally by means of DTA

BET

X-ray diffraction

electro-microscopy

infra-red spectroscopy

trichromatic observation

wetting angle determination

particle size evaluation

etc. It was found that the color difference between the α-and β-Copper Phthalocyanine was mainly due to the different manners of the piling-up of the primary pigment crystals. The influence of dilution temperature on the properties of α-Copper Phthalocyanine by the sulphuric acid pasting process was studied. A series of organic solvents which did not convert α-to the β-Copper Phthalocyanine was listed. The pigment properties of β-Copper Phthalocyanine after re-fluxing with these solvents were found to be materially improved. A crystal seeding method for the preparation of β-Copper Phthalocyanine from α-Cop-per Phthalocyanine was demonstrated to be superior to the commercial kneading method

on account of less energy consumption.