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US 6,485,558 B1Granted
Process for the preparation of pigment granules
AssigneeClariant GmbH
InventorsHans Joachim Metz, Heinfred Ohleier
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Abstract
The invention relates to a process for the preparation of pigment granules, which comprises adding a wax or a waxy polymer to an organic pigment during the finish in an organic or aqueous organic medium and spray-drying the aqueous suspension obtained after removal of the organic solvent by steam distillation or washing out with water.
Claims19
A process for the preparation of pigment granules comprising an azo pigment or a polycyclic pigment as an organic pigment, which comprises:
- adding a waxy polymer to the organic pigment during a finish process in
- an organic or aqueous organic medium comprising an organic solvent;
- removing the organic solvent from said organic or aqueous organic medium;
- forming an aqueous suspension comprising said organic pigment and water;
- and spray-drying the aqueous suspension to provide the pigment granules.
2 more elements
A process for the preparation of pigment granules, which comprises:
- a) heating a finely divided organic pigment;
- b) adding a wax and an organic or aqueous organic medium comprising an organic solvent to the organic pigment during a finish process to evenly coat the organic pigment with said wax;
- c) removing the organic solvent from said organic or aqueous organic medium;
- d) forming an aqueous suspension comprising said organic pigment and water;
- and
- e) spray-drying the aqueous suspension at a spray drying temperature above a drop point of the wax to provide the pigment granules having a generally spherical shape.
3 more elements
Dependencies are inferred from the claim text.