The C.I. pigment yellow the yellow azo pigment where the yellow azo pigment constituent

摘要

PPROBLEM TO BE SOLVED: To provide a relatively low cost yellow monoazo pigment or disazo pigment which has improved heat stability, high coloring power, and a high color developing property, and to provide a method for producing it. PSOLUTION: The yellow azo pigment composition which comprises (A) yellow azo pigment excellent in heat stability and with a heat stability index of 1.5 or less, and (B) yellow azo pigment inferior in heat stability and with a heat stability index of 2.0 or more, and which has a heat stability index less than 2.0. The method for producing the yellow azo pigment composition is comprised of dispersing (A) yellow azo pigment with an average particle size of at most 0.1μm and a heat stability index of 1.5 or less together with a coupling component of (B) yellow azo pigment with a heat stability index of 2.0 or more in a solvent, and coupling it by adding a diazonium salt of the (B) yellow azo pigment dropwise into the dispersion solution to produce the (B) yellow azo pigment as a composite with the (A) yellow azo pigment. PCOPYRIGHT: (C)2004,JPO&NCIPI