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Ken Ohmura, Tokyo JP

Ken Ohmura, Tokyo JP

Patent application numberDescriptionPublished
20080233507TWO COMPONENT DEVELOPER - A two component developer used in an electrophotographic method composed of a toner containing at least a resin and a colorant, and a carrier, is disclosed. The resin is composed of a polyester resin and a styrene-acryl resin, in which the polyester resin is prepared via condensation-polymerization of a polyvalent carboxylic acid and a polyol in a state where a styrene monomer and an acrylate monomer exist in an aqueous medium containing an acidic compound, followed by formation of the styrene-acryl resin via radical polymerization of the styrene monomer and the acrylate monomer; and the carrier comprises magnetic material powder dispersed in a binder resin, and has a volume based median diameter of 10 μm-100 μm, a shape factor SF-1 of 1.0-1.2, and a shape factor SF-2 of 1.1-2.5.09-25-2008
20090214974TONER FOR DEVELOPING ELECTROSTATIC IMAGE, FULL COLOR TONER KIT, AND IMAGE FORMATION METHOD - Disclosed is a toner for developing an electrostatic image, a full color toner kit comprising the toner and an image formation method employing the a full color toner kit, the toner comprising at least a resin and a colorant, wherein the colorant includes C.I. Pigment Blue 60 having a powder X-ray diffraction peak (2θ) at 6.3±0.2° and 13.0±0.2°.08-27-2009
20090239164TONER FOR ELECTROSTATIC IMAGE DEVELOPMENT, FULL-COLOR TONER KIT AND IMAGE FORMING METHOD - An electrophotographic toner for electrostatic image development which is capable of obtaining a high chroma full-color image exhibiting clear color without color contamination and excellent light stability is disclosed, comprising a resin and a colorant, wherein the colorant comprises a pigment of C.I. Pigment Blue 09-24-2009
20090239168TONER FOR DEVELOPING ELECTROSTATIC IMAGE, FULL COLOR TONER KIT, AND IMAGE FORMATION METHOD - Disclosed are a toner for developing an electrostatic image, a full color toner kit and an image formation method layer, the toner comprising at least a resin and a colorant, wherein the colorant includes quinacridone pigment having a number average primary particle size of from 30 to 150 nm and having a ratio of a long axis length to a short axis length of from 1.0 to 2.0.09-24-2009
20090246656TONER FOR ELECTROSTATIC IMAGE DEVELOPMENT, FULL-COLOR TONER KIT AND IMAGE FORMING METHOD - An electrophotographic toner for electrostatic image development which is capable of obtaining a high chroma full-color image exhibiting clear color without color contamination and achieving enhanced lightfastness is disclosed, comprising a resin and a colorant, wherein the colorant comprises a pigment of C.I. Pigment Red 209. There are also disclosed a full-color toner kit and an image forming method by use of the toner.10-01-2009
20090286176ELECTROPHOTOGRAPHIC COLOR TONER - A set of a yellow toner, a magenta toner, a cyan toner and a black toner is disclosed. Each of the color toners contains a colored particle and cerium oxide particles, the colored particle containing an amorphous polyester resin, a crystalline polyester resin, a colorant and a releasing agent; and the yellow toner contains C.I. Pigment Yellow 74, the magenta toner contains C.I. Pigment Red 122 and C.I. Pigment Red 238, the cyan toner contains any one of C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2 and C.I. Pigment Blue 15:3, and the black toner contains carbon black and any one of C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2 and C.I. Pigment Blue 15:3.11-19-2009
20100028798TONER FOR ELECTROSTATIC LATENT IMAGE DEVELOPMENT AND IMAGE FORMING METHOD - A toner for electrostatic latent image development, in which the image quality is fine, toner blister would not occur, and furthermore, the image quality which can fulfill customer's satisfaction can be obtained regardless of the temperature humidity environment in the image forming. The toner for electrostatic latent image development is made by agglomeration of resin particles and colorant particles in an aqueous medium. The acid value of the toner is less than 20 mgKOH/g, and the hydroxyl value of the toner is 7 to 57 mgKOH/g.02-04-2010
20100151377TONER AND MANUFACTURING METHOD OF TONER - Disclosed is a toner, comprising: a noncrystalline polyester resin; a crystalline polyester resin; a release agent; and a coloring agent, wherein the toner has a domain matrix structure in which the matrix comprises the noncrystalline polyester resin and the domain comprises the crystalline polyester resin and the release agent, and wherein the crystalline polyester resin includes within the release agent.06-17-2010
20100203442MANUFACTURING METHOD OF MAGENTA TONER FOR DEVELOPING ELECTROSTATIC IMAGE AND TONER - Disclosed is a manufacturing method of a magenta toner including the steps of dispersing an oil phase containing a radical polymerizable monomer for forming the binder resin and the colorant in an aqueous medium to form dispersion liquid in which the oil phase is dispersed in a form of droplets in the aqueous medium, and polymerizing the radical polymerizable monomer in the droplets in dispersion liquid to form resin particles containing colorant, in which the colorant comprises C.I. Solvent Red 48.08-12-2010
20100279223TONER AND METHOD FOR PRODUCING TONER - Disclosed is a toner including: a toner particle including at least a resin, a coloring agent and a mold release agent, wherein an average value e of degree of circularity of the toner particle is within 0.935=e=0.982, a maximum endothermic peak temperature of the mold release agent exists within 85-98° C., the resin includes at least non-crystalline polyester and crystalline polyester, and a ratio a of multivalent carboxylic acid of trivalent or higher-valent and a ratio c of straight chain aliphatic dial are such that 12.5=a=46, 20=c=65, 0.25=a/c=1.52, the multivalent carboxylic acid of trivalent or higher-valent and/or the straight chain aliphatic dial constituting the non-crystalline polyester and/or the crystalline polyester.11-04-2010
20100323290TONER AND MANUFACTURING METHOD THEREOF - A toner for an electrophotography and its manufacturing method are disclosed. The toner comprises toner particles containing a cross-linked polymer having two-valent crosslinking group represented by Formula (1),12-23-2010

Patent applications by Ken Ohmura, Tokyo JP