β-modified crystalline red pigment

摘要: A novel crystallographic modification (β-modification) of the pigment C. I. Pigment Red 53:1 is described and claimed which has characteristic reflection values in its X-ray diffraction pattern obtained by means Cu-K.sub.α radiation. This form reacting an aqueous solution alkali metal or ammonium salt formula 1 ##STR1## with equivalent amount a water-soluble barium presence compound 2 ##STR2## The distinguished more yellowish-red shade as compared to known α-modification.