BLACK COMPOSITE MICROPARTICLE POWDER AND DISPERSION CONTAINING THE SAME, AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide silica-included black composite microparticle powder high in coloring power and jetness and excellent in dispersibility, and to provide a dispersion containing the same in high dispersibility. SOLUTION: The black composite microparticle powder consists of black composite microparticles with silica included in carbon black, wherein its acid level is less than 0.3 mol/kg. The black composite microparticle powder is obtained by the following process: Silica particles and a surface modifier are mixed and agitated together to coat the surface of the silica particles with the surface modifier followed by addition of carbon black and making a mixing and agitation to obtain composite particles with the carbon black deposited on the surface of the silica particles coated with the surface modifier. Thereafter, part of the silica particles and part of the surface modifier in the resultant composite particles are dissolved using an alkaline solution. COPYRIGHT: (C)2008,JPO&INPIT