| 摘要 |
PURPOSE:To make the particle diameter of unstable type copper phthalocyanine large and not to damage the wiping properties of ink even in blending ink for letterpress printing with a large amount of copper phthalocyanine, by heat-treating copper phthalocyanine in sulfuric acid with a specific concentration, followed by hydrolysis. CONSTITUTION:Copper phthalocyanine is added to 55-70wt%, preferably 60- 65wt% sulfuric acid, for example, in a weight ratio of 1:6-11, and heat-treated at 80-110 deg.C for 1-3hr. Hydrolysis is carried out by adding a large amount of water, etc., to form unstable type copper phthalocyanine particles having relatively large average particle diameter of 0.5-2mu. The prepated filtration waste is dispersed into water, and water-insoluble fine silicate is deposited on the surface of the particles, to improve the affinity to the vehicle for letterpress printing ink. |
