PREPARATION OF COPPER PHTHALOCYANINE PIGMENT WITH INSTABILITY TO SOLVENT FOR INTAGLIO PRINTING INK

摘要

PURPOSE:To prepare the titled pigment with improved wipe-off characteristics when blended in large amts. into intaglio printing inks, by heat-treating copper phthalocyanine in the presence of sulfuric acid followed by hydrolysis. CONSTITUTION:Copper phthalocyanine is added to 1.0-10 times by wt., based on the amt. of phthalocyanine, of sulfuric acid having a concn. of 55-90wt%, heat-treated at 50-110 deg.C for 4-8hr and then hydrolyzed by adding water dropwise. The precipitate of the mixt. is filtered and dried to yield a copper phthalocyanine pigment with instability to solvents for intaglio printing inks having a specific surface area of 20-40m2/g.