Anhydrous free-flowing pigment pastes prodn. - by two=stage flushing, used in gravure printing inks

摘要

Process comprises first flushing an aq. pigment paste, amine(s), a binder and a naphthenic raffinate in a kneader with heating at 70-80 degrees C. the sepd. water is decanted off. Further aq. pigment paste, binder and naphthenic raffinate are added and the mixt. is again flushed at 70-80 degrees C in the kneader, followed by decanting off the water. The prod. is then dried at 70-90 degrees C and 10-20 Torr to residual water content 0-1% and diluted with a solvent. The obtd. pastes are esp. used in magazine gravure inks. They can be obtd. with high pigment concn. (>=50%), are easily pumped and dispersed, and ahave high colour strength. No rheological difficulties (e.g. gelation) occur in the obtd. gravure inks. The pastes can be used in inks based on toluene or petroleum.