| 摘要 |
PURPOSE:To improve dispersibility and to increase bonding strength to a resin by incorporating magnetic powder having a layer coated with a specific ketene dimer in a toner. CONSTITUTION:Magnetic powder having a layer coated by using the ketene dimer expressed by the formula is incorporated in a toner. Such coating layer is formed by dipping the magnetic powder in, for example, a toluene soln. of said detene dimer and drying the same after agitation. A magnetic toner is prepd. by using the magnetic powder subjected to the surface treatment in the above- mentioned way and using, for example, a methyl methacrylate/styrene copolymer, etc. as a binder resin, by which the excellent dispersibility of the magnetic powder is obtd. and the good bonding strength between the magnetic powder and the resin or wax. is obtd. |
