SINGLE-PHASE MIXED CRYSTALS OF LAKED MONOAZO DYES

摘要

ABSTRACT 1304/CHENP/2003 Single-phase mixed crystals of laked monoazo dyes Novel improved mixed crystals of monoazo dyes of formula wherein Ri is methyl or chlorine, and R2, R3 and R4 are each independently of the others hydrogen, methyl or chlorine, which dyes have been laked with alkaline earth metal cations and ammonium cations in a molar ratio of about 1 : 2. The mixed crystals are single-phase. The products according to the invention, while having a fine particle size, exhibit substantially better fastness properties than similar known products and are therefore excellently suitable as tinctoiially strong pigments. In addition, the part played by after-treatment is less critical. wherein Ri Is methyl or chlorine, R2, R3 and R4 are each independently of the others hydrogen, methyl or chlorine, R5, Re, R7 and Ra are hydrogen or methyl, and E is Mg, Ca or Sr, by crystallisation from an inert hydrophitic liquid in the presence of solvated cations E"*""*" and NRsReRyRa"*^. wherein the pigment is a single-phase mixed crystal and X is a number from 0.33 to 0.62 and y Is a number from 0.76 to 1.34, and the concentration of solvated cations E"*""*" at the beginning of the crystallisation is higher than the concentration of solvated cations NR5R6R7R6+- Three embodiments are disclosed. (FIG. 1)