METHOD FOR EVALUATING DISPERSIVENESS OF JAPANESE INK

摘要

PROBLEM TO BE SOLVED: To provide a method for evaluating dispersiveness of carbon black which can be used at any stage of the production process of Japanese ink and can be conducted quickly and readily. SOLUTION: A dispersion liquid where varnish or carbon black is aggregating or not is obtained by dispersing Japanese ink for lithographic printing under production or in completed state into an organic solvent having a solubility parameter of 8.4-10.5. Dispersiveness of original ink can be evaluated accurately by measuring the size of particles in the dispersion liquid or by separating the dispersion liquid centrifugally and judging transparency of supernatant.