Preparation of copper phthalocyanine pigments of the beta-modification
AssigneeBASF SE
InventorsKarl Roth, Rudolf Polster
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Abstract
Strong, transparent and readily dispersible copper phthalocyanine pigments are obtained by grinding the crude pigment in the presence of from 1 to 10% by weight (based on the crude pigment) of an organic liquid at from 90.degree. to 140.degree. C., the pigment forms obtained giving printing inks with very good flow characteristics.
Claims4
A process for preparing a strong, transparent and readily dispersible copper phthalocyanine pigment of the .beta.-modification consisting of grinding crude copper phthalocyanine in the absence of any grinding aids in the presence of from 1 to 10% by weight, based on the crude pigment, an organic liquid selected from the group consisting of di-C.sub.1 -C.sub.12 -alkyl phthalate, N-methylpyrrolidone, diethylene glycol, butoxyethanol, phenoxyethanol, ethylene glycol acetate, ethylene glycol diacetate and mixtures thereof, at from 90.degree. to 140.degree. C., and then recrystallizing the mill base in an aqueous organic phase.
Dependencies are inferred from the claim text.