Clariant patents organic pigments

Patent No. U.S. 7,056,378
Clariant has been granted a patent for a method of producing a vattable organic pigment comprised of vatting an aqueous or aqueous-organic suspension of a coarsely crystalline crude pigment and oxidizing the aqueous or aqueous-organic suspension of a coarsely crystalline crude pigment, wherein at least one of the steps of vatting and oxidizing further comprises milling the aqueous or aqueous-organic suspension of a coarsely crystalline crude pigment with a stirred ball mill operated with a power density of more than 1.0 kW per liter of milling space and with a peripheral stirrer speed of more than 12 m/s, under the action of grinding media with a diameter of less than or equal to 0.9 mm.