Pigments having improved colouristic properties and process for their preparation

Claim 1

A pigment of the formula which, measured in gravure printing with an applied amount after drying of 0.860 g/m 2 , of which pigment of the formula (I) accounts for 0.068 g/m 2 , printed on white kraft paper, gives after drying a lightness L* of not more than 48, a chroma C* of at least 53 and a hue angle h of from 295 to 315, the gravure printing ink being prepared by dispersing 30 parts by weight of pigment and 30 parts by weight of an aqueous solution containing 30% by weight of a dispersing resin dissolved therein and 7% by weight of isopropanol, based in each case on the weight of the solution, first with a laboratory dissolver at 6000 rpm and 23±2° C., for 15 minutes, then in a bead mill with ceramic beads of diameter 1.1±0.1 mm at 6000 rpm and 30±10° C., for 10 minutes, and diluting the resulting dispersion with 900 parts by weight of an aqueous solution containing 18% by weight of a polyacrylate dissolved therein and 15% by weight of isopropanol, based in each case on the weight of the solution, in a laboratory dissolver at 6000 rpm and 23±2° C. for 15 minutes.