| 摘要 |
PURPOSE:To obtain a toner having a uniform electrostatic charge characteristic by polymerizing a polymerizable monomer by a suspension polymn. method in the presence of carbon black having a specified volatile content and pH thereby dispersing uniformly and stably the carbon black into the toner. CONSTITUTION:The carbon black having 1-2% volatile matter when dried under heating for 7min at 950 deg.C, 3-4pH and preferably >=50cp, in 50% carbon black concn., the viscosity of the soln. after addition into the toner compsn. and after stirring at a high speed for one minute and about >=100cp, in 10% carbon concn. is prepd. Such carbon black, the polymerizable monomer (e.g., styrene) and polymn. initiator, etc. are uniformly mixed at a high speed. The mixture is then added to an aq. soln. contg. a suspension dispersant (e.g.; a mixture composed of calcium phosphate and sodium alkyl benzene sulfonate) and is suspension-polymerized, by which the titled toner is obtd. |
