To provide a yellow pigment having excellent color concentration and other properties, and being as a color index pigment yellow polymorphism capable of being further modified for improving the properties by a well-known method in the case of using as a coloring agent.
This pigment yellow 12 of a polymorphic color index having a new crystal modification exhibits an X-ray diffraction pattern giving three remarkable X-ray diffraction beams respectively corresponding to (d)-plane spacings of 11.82×10-10m, 7.71×10-10m and 3.32×10-10m. Furthermore, the pigment yellow 12 polymorphism is adjusted by coupling a tetrazo compound of 3,3'-dichlorobenzidine with acetoacetanilide in the presence of a polyamine, a polyether or a tertiary or a quaternary amine-based surfactant.
JIYON ANDORIYUU SUTAARINGU
KIYARORU JIIN FUARUNOTSUCHI
ROBAATO BURUUSU MATSUKAI
