Preparation of epsilon copper phthalocyanine of small primary particle size and narrow particle size distribution

摘要

A process of preparing copper phthalocyanine particles exhibiting a ε crystallographic form, comprising a heating step by heating at a temperature higher than or equal to 50°C copper phthalocyanine particles with more than 80 wt % of the particles exhibiting an α crystallographic form and less than 20 wt % of particles exhibiting an ε crystallographic form in the presence of a first organic liquid and optionally milling in the presence of beads.