Ricoh Company, Ltd.

Sanyo Chemical Industries, Ltd.

Tadao Takikawa

Masami Tomita

Shigeru Emoto

Shinichiro Yagi

Toshiki Nanya

Tomoyuki Ichikawa

Hiroto Higuchi

Fumihiro Sasaki

Naohito Shimota

Maiko Kondo

Naohiro Watanabe

Shuhei Yahiro

Hideki Sugiura

Yasuaki Iwamoto

Satoshi Mochizuki

Toshihiko Kinsho

Hidetoshi Noda

Hiroshi Yamashita

Hiroshi Yamada

Junichi Awamura

Tsunemi Sugiyama

Takahiro Honda

Yasuhiro Ono

Masakazu Iwata

Takashi Akutagawa

Yutaka Yoshida

Tsuyosi Izumi

Disclosed is a heat-fusible electrostatic image developing toner which has an excellent balance between fixability at low temperatures and grindability and is excellent in glossiness after fixing. Also disclosed is a resin for toners. A polyester resin for toners which is obtained by polycondensing a polyol component and a polycarboxylic acid component is characterized by containing 20-100 weight % of one or more polyester resins (A1) having a storage elastic modulus from 2.5&#xd7;10Pa to 5&#xd7;10Pa at 150&#xb0; C. wherein the molar average cohesive energy of the polyol component is between 7.0&#xd7;10and 1.4&#xd7;10J.

Polyester resin for toner, toner composition and resin particle

A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 &#x3bc;m to 7 &#x3bc;m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 &#x3bc;m to 2.0 &#x3bc;m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.

Toner for developing latent electrostatic image, container having the same, developer using the same, process for developing using the same, image-forming process using the same, image-forming apparatus using the same, and image-forming process cartridge using the same

A toner for developing an electrostatic image which has a small particle size essential for attaining a high-quality image, and can output a high-quality image excellent in frictional charging property and free from scumming. The toner for developing an electrostatic image has the volume average particle diameter of 2.0 &#x3bc;m to 7.1 &#x3bc;m and the surface condition of the toner is in scab form.

Toner for developing electrostatic image

Provided is a resin particle comprising a resin (a) and a filler (b) contained in the particle; the particle has a volume average particle diameter of from 0.1 to 300 &#x3bc;m and a shape factor of from 110 to 300; the particle has an outer shell layer (S) comprising at least a portion of the filler (b); the layer (S) is at least 0.01 &#x3bc;m thick and has a thickness that is &#xbd; or less of the maximum inscribed circle radius of the particle cross section. When used as a toner resin, it is excellent in blade cleaning properties and wide in the fixation temperature range; when employed as a paint additive or a cosmetics additive, it is excellent in masking properties; when used as paper coating additive, it is excellent in ink retention; when utilized as an abrasive, it is excellent in abrasion.

Resin particle and process of producing the same

A toner has a storage elastic modulus (G') of 500 Pa or more at a frequency of 1 Hz and temperature of 180&#xb0; C., while the toner is obtained by dissolving or dispersing a toner composition in an organic solvent, further dispersing the solution or dispersion thereof in an aqueous medium containing fine resin particles as well as being reacted with a compound having an active hydrogen group, and removing the solvent from the obtained aqueous dispersion.

Toner, developer using the same, toner container using the same, process cartridge using the same, image-forming process using the same and image-forming apparatus using the same

A toner capable of making compatible a transferring property, a fixing property and a cleaning property and forming a high-precision image. The toner comprises a binder resin and a colorant and is characterized in that the average circularity of the toner is at least 0.95, a ratio (D/S) between the total projection area (S) and the contact area (D) of the toner is 15% to 40%, and the contact area (D) is a total contact area between the toner and an object surface. The toner has such a shape as to be able to contact a latent image carrier with a proper contact area, has a high transferring rate and can prevent transferring dust.

Toner, developer, image developing apparatus, and image forming apparatus

A toner for developing latent electrostatic images is in the form of particles prepared by dissolving or dispersing each component of a composition in an organic solvent to form a solution or dispersion, the composition containing at least a resin reactive with a compound having an active hydrogen group, a compound having an active hydrogen group, a coloring agent, a releasing agent, and a graft polymer C of a polyolefin resin A on which a vinyl resin B has been at least partially grafted; dispersing the solution or dispersion in an aqueous medium; reacting the reactive resin with the compound having an active hydrogen group; removing the organic solvent during or after the step of reacting; and washing and drying particles formed by removing the organic solvent.

Toner and developer for developing latent electrostatic images, and image forming apparatus

A dry toner contains at least a toner binder, organic fine particles, a colorant, a wax, a charge control agent, and an external additive. The wax is concentrated in the vicinity of a toner core including the toner binder, colorant and wax. The organic fine particles adhere to the surface of the toner core to form a base toner-particle, the fine particle of charge control agent adhere to the surface of the base toner-particle, and the external additive is located on the surface thereof.

Dry toner, and process cartridge, image forming process and apparatus using the same

The present invention is directed to a toner for electrophotography that exhibits excellent hot offset resistance, storability, and glossiness and can obtain a high image-resolution and highly detailed images when used for energy saving apparatuses or as a color toner. The present invention is also directed to a developer, image-forming apparatus, and process cartridge containing such toner, and image-forming process using such toner. The toner of the present invention contains a resin and wax. The wax is dispersed within the resin in a shaped of fine particles to form a toner particle. In the toner particle, more dispersed wax particles are existed in a surface portion of the toner particle than a centric portion of the toner particle.

Toner for electrophotography, developer using the same, process cartridge using the same, image-forming apparatus using the same, and image-forming process using the same

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Aichi, Japan

Tadao Takikawa