THE COMPOSITION OF A BEAD-TYPED RESIN USED IN A DRY TONER FOR DEVELOPING AN ELECTROSTATIC IMAGE

摘要

A composition for forming a spherical resin used in the toner for developing an electrostatic image is provided to improve concentration of image by controlling the distribution of particle size of spherical resin particles to be narrow. A composition for forming a spherical resin is obtained by water-dispersion suspension polymerizing a monomer mixture comprising 100 parts by weight of a lipophilic monomer which is polymerized to impart charge characteristics and 0.05-2 parts by weight of an acrylate-based polar monomer which imparts surface polarity in an aqueous medium containing a crosslinking agent and a dispersion stabilizer. Preferably the lipophilic monomer comprises styrene and at least two compounds selected from n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl (meth)acrylate and stearyl (meth)acrylate.