Mita Industrial Co., Ltd.

Kyocera Mita Corporation

Tomohide Iida

Takayuki Itakura

Koji Kuramashi

Takashi Nagai

Nobuyasu Honda

Takashi Teshima

Yoshiteru Hatase

Nobuaki Kawano

Hideaki Kawata

Hidekazu Tamura

Toshiaki Akiyama

Hirofumi Horio

Asao Toda

Tadao Sumiyoshi

A two-component-type developing agent comprising a silicone resin-coated carrier and a positively charging toner, the silicone coated carrier having an average particle diameter of from 60 to 110 .mu.m, the silicone resin coating having an average thickness of from 0.1 to 0.3 .mu.m, the carrier having a resistivity of from 1.5.times.10.sup.8 to 1.5.times.10.sup.11 .OMEGA..multidot.cm, the toner concentration being from 3.0 to 5.0 % by weight and the amount of electric charge by friction of the toner based on the suction method being from +10 to +20 .mu.c/g. The silicone resin-coated carrier and the developing agent feature long life without permitting the spent toner to adhere on the carrier surfaces, without permitting the carrier coating to peel off even after repetitively used for extended periods of time, featuring stable amount of electric charge by friction, stable developing properties, and maintaining favorable image quality for extended periods of time developing none of carrier dragging, toner scattering in the machine, background fogging or defective image density.

Carrier for electrostatic latent image developing and two-component-type

The present invention provides a method for impression development which comprises forming a thin layer of a toner on a surface of a developing roller with a plate-like rigid member, and developing an electrostatic latent image formed on a photoconductor by contacting the thin layer with the electrostatic latent image. The toner comprises toner particles, and prescribed amount of inorganic fine particles (mean particle diameter of 0.1 to 1.0 .mu.m on the volume basis), and/or comprises toner particles which have prescribed distribution of the odd-shape degree of the toner particle (mean value of the odd-shape degree and the proportion of the number of toner particles having the odd-shape degree of not more than 0.2). According to the method for impression development, it becomes possible to form an image having no failures and good image quality.

Method for impression development

A magnetic carrier for electrophotographic developing agent wherein the surfaces of the magnetic core particles are partly coated with a thermosetting resin and a small amount of a low-melting or low-softening thermoplastic resin or wax, and at least recessed portions of the core particles are filled with these coating materials. The magnetic carrier has an electric resistance that is maintained within a range that is suited for forming the image, and suppresses the occurrence of spent toner.

Magnetic carrier for electrophotographic developing agent and method of

The present invention provides a toner composition comprising a toner and a hydrophobic silica composed of a fine powder of silica treated with a compound having a polymethylsilyl group in the molecule.

Toner composition for developing an electrostatic latent image and an

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Osaka, Japan

Tomohide Iida