PURPOSE: A dispersant for suspension polymerization, which is excellent in the ability to stabilize dispersed particles of a polymerization composition in an aqueous dispersion medium, prepared by treating a difficultly soluble metal carbonate powder with a hydrophobicity modifier.
CONSTITUTION: A difficulity water-soluble metal carbonate powder is treated with a hydrophobicity modifier, and the resulting modified metal carbonate powder is employed as a dispersant for suspension polymerization treatment. Said dispersant enables a polymerization composition containing monomers and other necessary components to disperse in a dispersion medium in suspension polymerization and to polymerize in situ. By treating the polymer particles thus produced with a dil. acid, the dispersant occluded in the particles is removed. This dispersant is advantageous in the production of toners for developing static charge images. In such an application, a coloring matter together with said monomer is used, and in an application where a magnetic toner is produced, a magnetic substance powder also is added.
TAMAKI KIYOSHI
MURATA HIDENORI
TERADA SADAJI
TAKAGIWA HIROYUKI
