Relationship between Surface Character of Copper Phthalocyanine Blue Pigment Particle and Surface Potential -Surface Potential in Solvents and/or Acry lic Monomers-

Abstract

Study of suspension stability related to the surface potential of pigment particle in nonaqueous system has been scarcely done due to the complicated ionization phenomena. However, the surface potential of dispersed particles is very important for the study of dispersion stability.
Surface potential of three different copper phthalocyanine pigme nts was measured in solvents and/or acrylic monomers. The copper phthalocyanine pigment samples having three differrent surface characters were prepared by surface treatment using amino derivative and sulfonated derivative of copper phthalocyanine compound.
Dispersion sta bility was obtained in the system where surface potential was recognized, and the surface potential was deeply related with the polarization and the dissociation of the polar solvents and/or monomers adsorbed on the surface of pigment particles. The permittivity of the system was measured to estimate the polarization and the dissociation of the polar solvents and / or monomers.
The interaction between the surface of pigment particle and the polar solven ts and monomer molecules was quite different in each pigment's surface.