Magnetic toner for electrostatic charge latent image development

Abstract

Abstract PURPOSE: To obtain the dry type developer (magnetic toner) which is used for the electrophotographic apparatus whose conductive sleeve for development is grounded with high resistance and which is capable of forming good images by covering magnetic toner particles with the specific non-magnetic fine particle groups. CONSTITUTION: Ferromagnetic material fine particles such as iron, cobalt, ferrite or other, waxes, thermosplastic resins such as styrene base resins or other and pigments and dyes are kneaded and melted, and the mixture is cooled and pulverized, whereby the magnetic toner particles being fine powder are formed. Next, non-magnetic fine particles having electrical insulation characteristic of grain sizes smaller than those of the above-mentioned toner particles (preferably oil-soluble dyes, gold-contained dye particles, etc.) (A) and conductive non-magnetic fine particles (preferably graphite, metal powder, etc.) (B) are added at about 0.01W3wt% (however, A is used more than B) based on the weight of the above-mentioned toner particles and are deposited on their surfaces, whereby the dry type developer (magnetic toner) is obtained. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Tsuneaki Kawanishi
• 👤 Akio Kobi
• 👤 Yasusada Morishita
• 👤 Koji Noguchi
• 👤 Masumi Asanae

Bibliographic Details