β-modified crystalline fed monoazo pigment

摘要: The invention relates to a novel crystallographic modification (β-modification) of the pigment formula I ##STR1## β-modification shows reflections in Cu-K.sub.α radiation X-ray diffraction spectrum at following angles 2θ (accuracy ±0.2°): 21.95° maximum high intensity, 5.40°, 7.30°, 10.85°, 14.50° and 27.60° maxima medium intensity 10.05°, 12.80°, 16.40°, 17.95°, 24.65° 25.80° low intensity. is obtainable by coupling diazotized N-(3-amino-4-methylbenzoyl)-sulfanilic acid an aqueous presence or absence organic solvent onto alkali-dissolved 2-hydroxy-4'-methoxy-3-naphthanilide laking product adding calcium salt, least one cation-active surfactant having been added latest prior laking, heating suspension laked azo dye temperature 130° 180° C. suitable for pigmenting printing inks, surface coatings, plastic compositions, filaments paper, particular polystyrene, copolymers based on polyolefins, polyolefins polyvinyl chloride.