Minolta Company, Ltd.

Koichi Takenaka

Tomoharu Nishikawa

Hideaki Yasunaga

Makoto Kobayashi

Hiroshi Shibano

Hiroyuki Fukuda

Yoshitsugu Morita

Haruhiko Furukawa

Hiroshi Ueki

Osamu Maeda

A carrier having a BET specific surface area of 0.50 to 2.00 m,and a dynamic current value of 15 to 170 nA and a two-component developer comprising such a carrier and toner.

Carrier having specified bet specific surface area and dynamic current value and two-component developer thereof

A two-component developing agent which is made from at least a carrier and a toner, characterized in that bulk specific density (AD.sub.1) of the carrier is set at 1.07 to 1.43 g/cc, bulk specific density (AD.sub.2) of the developing agent is set at 0.83 to 1.16 g/cc and AD.sub.2 /AD.sub.1 is set at 0.69 to 0.91. The present invention includes an image-forming method and an image-forming system, in which the above two-component developing agent is used.

Two-component developing agent and image forming method using such a

The present invention relates to a binder carrier comprising at least magnetic particles and a binder resin. The binder resin contains a thermoplastic silicone-modified acrylic resin which is a copolymer of a polydiorgano-siloxane macromer having an acrylic functional group and a radical-polymerizable organic monomer. The binder carrier of the present invention a long-life binder carrier which eliminates the possibility of carrier deterioration due to toner components, such as a charge-controlling agent and an after-treatment agent, and which is less liable to deteriorate in its chargeability.

Binder carrier

The present invention relates to a binder carrier, comprising at least magnetic particles and a binder resin, characterized in that the binder resin comprises a thermoplastic silicone-modified acrylic resin and an amino-group-containing resin. The binder carrier is capable of preventing carrier degradation caused by toner ingredients such as a charge-control agent and a post-processing agent for the toner. The binder carrier of the present invention has a long life with less susceptibility to degradation in charging performance, and makes it possible to quickly charge the toner sufficiently.

Binder carrier comprising magnetic particles and specific resin

The present invention relates a carrier comprising: a core particle comprising a binder resin and a first magnetic powder dispersed therein; and a second magnetic powder adhered onto the surface of the core particle, said second magnetic powder having a relative surface area larger than that of the first magnetic powder.

Carrier and developer for developing electrostatic latent images

The present invention provides a binder carrier containing at least a magnetic particle and a binder resin, in which the binder resin comprises at least a copolymer containing an ethylenic unsaturated nitrile and preferably an optional silicone-modified acrylic resin.

Binder carrier containing ethylenic unsaturated nitrile copolymer as

A developing method for developing electrostatic latent images comprising:

developing method using an oscillated electric field and including a

Carrier particles for electrostatic latent image development comprising first particles comprising a binder resin and a magnetic powder dispersed therein and second particles comprising a binder resin and a magnetic powder dispersed therein, said second particles having an average particle size smaller than said first particles, said magnetic powder contained in the first particles has a residual magnetization smaller than that of said magnetic powder contained in the second particles.

Carrier and developer for electrophotographic latent image development,

A development method comprising the steps of forming a layer of a developer comprising a toner and a magnetic carrier on a developer transporting member containing a magnet therein by means of a developer regulating member, transporting the developer layer on the developer transporting member to a development region where the developer transporting member opposes an image bearing member, and applying an oscillating electric field to the development region for supplying the toner from the developer layer to the image bearing member, thereby developing an image. The magnetic carrier comprises a magnetic powder dispersed in a binder resin having an acid value of 0 to 20 KOHmg/g and has 5 to 30 wt % of magnetic powder present on the surface thereof.

Development method

A carrier for electrostatic latent image developing for use in methods of developing an electrostatic latent image formed on the surface of a latent image-bearing member by transporting a developer comprising a toner and a carrier via the rotation of a developing sleeve having a built in stationary magnet roller, the carrier for electrostatic latent image developing including magnetic powder dispersed in a binder resin and having a saturation magnetization of about 50 to about 80 emu/g, residual magnetization of about 3 to about 10 emu/g, and coercive force of about 20 to about 50 oersted.

Carrier for electrostatic latent image developing

The present invention provide a carrier for development of electrostatic latent images, comprising magnetic powder dispersed in binder resin, the carrier having a mean particle size in a range of 30 to 80 .mu.m and satisfying the following relational expression:

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Itami, Japan

Koichi Takenaka