Sharp Kabushiki Kaisha Corporation

Yui Kawano

Keiichi Kikawa

Yoritaka Tsubaki

Tadayuki Sawai

Keigo Mitamura

Shintaro Fukuoka

Toner of one aspect of the present invention has a weight average molecular weight Mw of 30,000&#x2266;Mw&#x2266;95,263 as determined from a molecular weight distribution based on GPC, includes a THF-insoluble gel component at a weight proportion of less than 5%, and includes components each having a molecular weight of 500 to 1500 which components have an area occupancy of 4% to 10% on a chart of the molecular weight distribution based on GPC.

Method for producing ground toner

A two-component color developer containing a toner and a resin-coated carrier, the toner containing at least a polyester resin as a binding resin, an organic pigment as a colorant and inorganic fine particles as an external additive, wherein the inorganic fine particles have a negative polarity, the toner has a volume resistivity of 40&#xd7;10to 220&#xd7;10&#x3a9;cm and a negative polarity, and the carrier has a coat durability of 90% or greater.

Two-component color developer and image formation device using same

Toners of respective colors of a full-color toner set each contain a binder resin which is polyester resin; and a release agent dispersing aid which is styrene acrylic copolymer resin having at least one of an &#x3b1;-methylstyrene structure and a styrene structure. The styrene acrylic copolymer resin is contained in an amount of 7 parts by weight to 14 parts by weight with respect to 100 parts by weight of the polyester resin. The full-color toner set has a sum of resistivities of the toners of the respective colors of 410&#xd7;10to 510&#xd7;10(&#x3a9;&#xb7;cm).

Full-color toner set, full-color developer set, image-formation method using same, and image-formation device

A coated carrier that peeling and wearing of a coating layer are hard to be generated and a method of manufacturing the coated carrier are provided. The coated carrier includes a core particle including a magnetic body, a first resin layer coating the core particle, a resin particle layer including a resin particle fixed to the first resin layer as a single layer, and a second resin layer. The first resin layer includes a first resin having a first reactive group. The resin particle layer is formed of resin particles including a cross-linking resin having a second reactive group which can undergo a cross-linking reaction with the first reactive group. The second resin layer is provided so as to fill gaps between the resin particles.

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Osaka, Japan

Yui Kawano