| 摘要 |
PURPOSE:To sharpen an electrostatic charge quantity distribution and to speed up the rise of electrostatic charge as well as to stabilize an electrostatic charge quantity by further adding magnetic particles externally to magnetic toner particles internally added with a charge control agent of a specific mol. wt. CONSTITUTION:This developer is constituted of the magnetic toner formed by adding the magnetic particles further to the magnetic toner particles contg. magnetic powder and resin and a carrier. The charge control agent of a low mol. wt. polymer of 1,000 to 20,000 weight average mol. wt. is compounded with this tone. A copolymer of an ethylenic monomer having a sulfo group and other ethylenic monomer; for example, a copolymer of styrene (90)-2- acrylamide-2-methyl propane sulfonic acid (10), etc., are usable for this control agent. The flocculation of the toner and the generation of white lines, etc., are obviated and the sticking of the toner to a sleeve is obviated as well if this developer is used. |
