Method for the production of pure C.I. pigment orange 74
AssigneeClariant Finance (BVI) Limited
InventorsThomas Hundsdorf, Willi Rauschmann
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Abstract
The invention relates to a method for conditioning and purifying pigment orange 74. The method is characterized in that the aqueous suspension of the raw pigment, optionally after adding an organic solvent from the group comprising isobutanol, chlorobenzene and o-dichlorobenzene, is subjected to a finishing treatment, the organic solvent is optionally removed using a distillation process, the remaining aqueous pigment suspension is mixed with a non-ionic surfactant and is heated to a temperature ranging from 30 to 100° C. and the pigment is then filtered off.
Claims14
A process for preparing pure C.I. Pigment Orange 74, comprising the steps of subjecting an aqueous suspension of crude C.I. Pigment Orange 74 pigment, optionally after addition of one or more organic solvents selected from the group consisting of isobutanol, chlorobenzene and o-dichlorobenzene, to a conditioning treatment, removing any organic solvent by distillation, admixing the remaining aqueous pigment suspension with a nonionic surfactant, bringing the admixture to a temperature of 30 to 100° C. and filtering off the pigment.
Dependencies are inferred from the claim text.