Electric charge type magnetic toner

Abstract

Abstract PURPOSE:To obtain images which are superior in density, resolution, etc. and are free from ground photographic fogs by containing an electric charge control agent in magnetic toner particles in a magnetic toner consisting of magnetic powder and a binder resin. CONSTITUTION:A magnetic toner consisting of about 30-70wt% magnetic powder of about 0.1-5 microns grain sizes of magnetic metal such as magnetite, nickel, iron, etc., and about 70-30wt% a binder resin such as ethylene-vinyl acetate copolymer is mixed with 0.1-10wt% an electric charge control agent, whereby an intended electric charge type magnetic toner is obtained. Fine particles of about <=30mu of nigrosine type dyes (e.g., Nigrosine Base EX), metallized dyes (e.g.; Valifast Black 3804), etc. are preferable as the electric charge control agent. The resultant magnetic toner has superior effet in both developing and electrostatic transfer with respect to an electrostatic charge latent image system, and is effective in electrostatic transfer in a magnetic latent image system.

Inventors

• 👤 Koji Noguchi
• 👤 Takaharu Goto
• 👤 Yasuto Doi

Bibliographic Details