| abstract |
The use of an azo pigment of the formula (1) as a colorant in electrophotographic toners, electrophotographic developers, powders and powder coatings, and electret materials, wherein said azo pigment is prepared in the presence of 20 to 50% by weight of an auxiliary selected from the group consisting of a rosin, a salt of a rosin, an abietic acid, and a salt of an abietic acid, wherein said weight is based on the overall weight of the azo pigment including said auxiliary, and wherein the azo pigment has a specific surface area of more than 70 m2/g and the azo pigment particles comprising the azo pigment have a length-to-width ratio of on average less than 2.8:1 and a mean particle size d50 of less than 130 nm. |