Ricoh Company, Ltd.

Tohoku Ricoh Co., Ltd.

Other

Teijin Limited

Yuji Natori

Fumiaki Arai

Masanori Rimoto

Hiroshi Tateishi

Takehiko Iwaoka

Tetsuo Tanaka

Shin Hasegawa

Keishi Taniguchi

Minoru Hakiri

Masayasu Nonogaki

Shigeo Hatada

Hideyuki Yamaguchi

Yasuyuki Hosogi

Tomiaki Ito

Masayuki Ohta

Hideki Ono

Hachiro Tosaka

Shoichi Sugiyama

Akihiko Matsuyama

Minoru Matsuo

Hiroshi Tomita

Hachiroh Tosaka

Hitoshi Ueda

Kotaro Kato

The present invention provides a magenta recording ink composition including at least a solid solution pigment (A) containing quinacridone, a lake pigment (B) having a xanthene structure, an aqueous solvent, and water, wherein the solid solution pigment (A) has visible light absorption peaks at wavelength ranges of from 510 nm to 530 nm and from 540 nm to 560 nm, and a mass ratio (B/A) of the lake pigment (B) to the solid solution pigment (A) falls within the range of 0.1 to 5.

Magenta recording ink composition, inkjet recording method, and ink recorded matter

The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.

Water-based pigment dispersion, production method thereof, water-based pigment ink, production method thereof, ink record, inkjet recording apparatus, and inkjet recording method

The present invention provides a pigment dispersion that contains a carbon black, a dispersing agent and water, wherein the carbon black is any one of a channel black and a gas black, the dispersing agent is a sodium naphthalenesulfonate formalin condensate, and the total content of a dimer, a trimer and a tetramer of naphthalenesulfonate in the sodium naphthalenesulfonate formalin condensate is 20% by weight to 80% by weight. The present invention also provides an inkjet ink using the pigment dispersion.

Pigment dispersion, inkjet-ink using the pigment dispersion, image forming process, and image forming apparatus

The toner according to the present invention may be produced from a toner raw composition which comprises a foaming agent, a binder resin and a colorant, wherein the colorant comprises a black metal compound, the foaming agent has a volume-average particle diameter of 2 &#x3bc;m to 50 &#x3bc;m, the toner raw composition turns into a porous mixture while the foaming agent expands at melting and kneading the toner raw composition, and the toner obtained through milling and classifying the porous mixture has a specific density of 1.0 g/cmto 1.3 g/cm, wherein the specific density is determined as follows: 1 gram of toner is pressed at 400 kgf/cmfor five minutes in a discal cavity having a diameter of 20 mm, then the discal toner is removed; the discal toner volume (V) is calculated from the diameter and height, measured at 10 minutes after releasing the pressure on the discal toner, and the discal toner mass (W) is measured; then the specific density is determined from the following formula: Specific Density (&#x3c1;)=W/V.

Toner, developer, container containing toner, process, cartridge, image forming apparatus and process

A thermosensitive stencil paper having a thermoplastic resin film and a porous resin layer which is provided on the thermoplastic resin film by coating a porous resin layer formation coating liquid including a water-in-oil emulsion of a resin on the thermoplastic resin film and drying the coating liquid. In addition, the method of producing the above-mentioned thermosensitive stencil paper is also disclosed.

Thermosensitive stencil paper and method of producing the same

Disclosed is an intermediate transferring belt utilized in order to transfer a toner image formed by developing a latent image on an image bearing member by means of a toner,

Intermediate transferring belt and process for producing the same, image forming apparatus, and image forming process

A toner for developing an electrostatic latent image, including toner particles each containing a black colorant and a binder resin, wherein the black colorant comprises a metal oxide having a number average particle diameter in the range of 20 to 100 nm in an amount of 10 to 40% by weight based on a total weight of the toner particles.

Black toner, image forming method and image forming apparatus using the toner

A heat-sensitive stencil including a resin film on which a thin resin layer and a porous resin layer are formed in succession.

Heat-sensitive stencil, process of fabricating same and printer using same

A heat-sensitive stencil having a thermoplastic resin film, and a porous resin layer formed thereon. The stencil has an air permeability in the range of 1.0 cm /cm &middot;sec to 157 cm /cm &middot;sec in a portion thereof when the thermoplastic resin film of the portion is perforated to form perforations providing an open ratio S /S of at least 0.2, wherein S represents a total area of the perforations and S represents the area of the portion. The heat-sensitive stencil is prepared by applying a coating liquid containing the resin of the porous resin layer to the thermoplastic resin film and drying the coating. The coating liquid contains a mixture of a good solvent and a poor solvent less vaporizable than the good solvent so that the porous resin layer is formed after drying.

Heat-sensitive stencil and method of fabricating same

A heat-sensitive stencil having a thermoplastic resin film, and a porous resin layer formed thereon. The stencil has an air permeability in the range of 1.0 cm.sup.3 /cm.sup.2 .multidot.sec to 157 cm.sup.3 /cm.sup.2 .multidot.sec in a portion thereof when the thermoplastic resin film of the portion is perforated to form perforations providing an open ratio S.sub.O /S.sub.P of at least 0.2, wherein S.sub.O represents a total area of the perforations and S.sub.P represents the area of the portion. The heat-sensitive stencil is prepared by applying a coating liquid containing the resin of the porous resin layer to the thermoplastic resin film and drying the coating. The coating liquid contains a mixture of a good solvent and a poor solvent less vaporizable than the good solvent so that the porous resin layer is formed after drying.

A thermal stencil plate making method, by which a perforation image is formed on a thermal stencil original sheet comprising a thermoplastic resin film and a porous support laminated on each other or a thermal stencil original sheet composed substantially only of a thermoplastic resin film by applying thermal energy to the thermal stencil original sheet by means of a thermal head, is characterized in that a distance between heating elements in the thermal head: d (.mu.m) and a thickness of a heating element protection layer: T (.mu.m) satisfy the following condition of Equation (1) and that a secondary scan direction heating element spacing between heating elements in the thermal head: D (.mu.m) and the thickness of the heating element protection layer: T (.mu.m) satisfy the following condition of Equation (2):

Growing community of inventors

Numazu, Japan

Yuji Natori