Reduction- and oxidation-stable iron oxide black pigments having high colour strength for colouring plastics and building materials, their preparation and their use

Iron oxide black pigment having

• a colour shift ΔE* according to DIN 53772 and DIN 6174 at 260° C. of <0.7, in particular of <0.5;
• on incorporation into HDPE, and
• oxidation stability at 140° C. according to the IMCO test, and
• an extension ratio for the colour depth characteristic B 1/9 according to DIN 53235 Parts 1 and 2 of >1.9.