Canon Kabushiki Kaisha

Mitsuru Uchida

Hiroyuki Kobayashi

Kenji Okado

Satoshi Yasuda

Seiichi Takagi

Tetsuya Kuribayashi

Yusuke Karami

Tohru Matsumoto

A plastic additive containing thermoplastic polymer is provided in which the glass transition temperature of the thermoplastic polymer is from 40.degree. C. to 80.degree. C., and the plastic additive has magnetic particles dispersed therein. Also, a plastic composition containing an additive containing a thermoplastic polymer and plastic is provided in which the glass transition temperature of the thermoplastic polymer is from 40.degree. C. to 80.degree. C., and the plastic composition has magnetic particles dispersed therein. In addition, a molding formed of a plastic composition containing an additive containing thermoplastic polymer and plastic is provided in which the glass transition temperature of the thermoplastic polymer is from 40.degree. C. to 80.degree. C., and the molding has magnetic particles dispersed therein.

Plastic additive, plastic composition containing the additive and

Four color toners of yellow, magenta, cyan and black, and four two-component developers containing the four color toners respectively in combination with a resin-coated ferrite carrier suitable for multi-color electrophotographic copying are provided Each of the four-color toners is strictly regulated in relation not only to the carrier but also to the other color toners. More specifically, each color toner is strictly controlled with respect to a particle size distribution, freeness from agglomeration, melting characteristics including heat-absorption peaks and apparent viscosity on melting, chromaticity, triboelectric chargeability and optical toner concentration detection characteristic. Because of the strict regulation of these various parameters, the resultant multi-color toner or developer system shows excellent performances at every stage of multi-color electrophotography including development, transfer and fixing (color-mixing) for a long period of successive copying.

Color toner and two-component developer containing same

Four color toners of yellow, magenta, cyan and black, and four two-component developers containing the four color toners respectively in combination with a resin-coated ferrite carrier suitable for multi-color electrophotographic copying are provided. Each of the four-color toners is strictly regulated in relation not only to the carrier but also to the other color toners. More specifically, each color toner is strictly controlled with respect to a particle size distribution, freeness from agglomeration, melting characteristics including heat-absorption peaks and apparent viscosity on melting, chromaticity, triboelectric chargeability and optical toner concentration detection characteristic. Because of the strict regulation of these various parameters, the resultant multi-color toner or developer system shows excellent performances at every stage of multi-color electrophotography including development, transfer and fixing (color-mixing) for a long period of successive copying.

Method of forming a multicolor image with color toner and two-component

A toner for dry electrophotography comprises a binder resin, a metal complex compound (A) of an aromatic hydroxycarboxylic acid having a lipophilic group, and a metal complex salt-type monoazo dye (B) having a hydrophilic group. The compound (A) functions to enhances the negative triboelectric chargeability of the toner, and the dye (B) functions to leak an excessive charge of the toner, so that the toner is caused to have a uniform and sharp triboelectric charge distribution. As a result, the toner involves little liability of causing 'tailing', an irregularity caused by undesirable toner scattering.

One-component toner for dry electrophotography containing metal complex

A magnetic dry developer, comprising negatively chargeable insulating magnetic toner particles containing, at least, a binder resin, a magnetic substance, and an organo-chromium or -zinc complex; cerium oxide particles containing CeO.sub.2 as a predominant component and having a volume average particle size of 1.0 to 4.0 microns, a heating loss of 0.5 wt. % or less on heating up to 100.degree. C. and a BET specific surface area of 15 m.sup.2 /g or less as measured by the nitrogen adsorption method; and hydrophobicity-imparted negatively chargeable silicon oxide particulates. The cerium oxide particles have a function of disintegrating particularly the hydrophobicity-imparted silicon oxide particulates and enhance the attachment thereof to the toner particles, whereby the developing characteristics including the magnetic triboelectric chargeability are stabilized from the initial stage of electrophotographic copying operation.

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Chofu, Japan

Mitsuru Uchida