Patent ID: 7608117
Filing Date: 2009-10-27
Classification: C09B

Abstract:
1. A method of producing a granular formulation of a colorant that is soluble in plastics, which granular formulation comprises from 91.5 to 99.8% by weight of a colorant soluble in plastics, from 0.1 to 5.0% by weight, calculated with respect to the weight of colorant, of a polyvinylpyrrolidone and, from 0.1 to 3.5% by weight, calculated with respect to the weight of colo-rant, of a viscosity regulator which process comprises suspending in water a filter cake obtained from preparation of the colorant, said colorant being selected from the group of solvent dyes, adding thereto from 0.1 to 5.0% by weight, calculated with respect to the weight of colorant, of a polyvinylpyrrolidone and from 0.1 to 3.5% by weight, calculated with respect to the weight of colorant, of a viscosity regulator and, where appropriate, further adjuvants, and then drying the aqueous suspension to form granules with a particle size of from 5 to 1000 microns.