| 摘要 |
PURPOSE:To obtain superior durability and humidity resistance by emulsifying a water-soluble polymn. initiator in the presence of an emulsifier and solidifying the obtained polymer dispersion at a temp. of its glass transition point or higher, or heating the solidified polymer particles at said temp. or higher. CONSTITUTION:The polymerizable monomer, a colorant and/or a magnetic powder, and an oil-soluble polymerization initiator, and a water-soluble polymerization initiator in an amt. smaller than the former initiator are emulsified in the presence of an emulsifier, and the obtained polymer dispersion is solidified at a temp. of its glass transition point or higher, or the obtained solidified particles are heated to such temps. The polymn. is performed after emulsification or during emulsification operation at a temp. of 20-120 deg.C to attain >=99wt% polymn. yield. The emulsifier is added in an amt. of 0.01-10wt% of the polymerizable monomer, and as a solidifying agent, magnesium sulfate and/or aluminum sulfate and/or an inorg. salt are used in an aq. soln. of 0.1-10wt%, thus permitting the obtained toner to be enhanced in durability and humidity resistance, and the image formed with this toner to be superior in resolution, image density, and gradation. |
