| 摘要 |
PURPOSE:To facilitate control of particle size and to uniformize it by additionally using as a dispersant a fine silica powder having a specified value of a specific surface area measured by the BET method in the course of polymn. other than a dispersant added in the initial stage. CONSTITUTION:A polymerizable mixture composed of cationic monomers are stirred in the presence of an initial dispersant and an additidonal dispersant to suspend the mixture in a dispersion medium, such as water, to advance polymn. The dispersant used as the initial dispersant is an anionic fine silica powder suitable for giving suspended particles having a desirable particle size and distribution and a specific surface area of >=30m<2>/g measured by the BET method. The dispersant used as the additional one is a fine silica powder having a specific surface area of 130-300m<2>/g measured likewise. An electrostatic charge image developing toner uniformly electrostatically chargeable and capable of forming an image high in resolution and gradation can be prepared with a narrow particle size distribution and high yield by adding the additional dispersant and stable dispersion can be maintained even in the presence of a polymn. inhibiting additives. |
