Having Specified Toner Particle Size Distribution Patents (Class 430/110.4)
  • Publication number: 20090202935
    Abstract: A carrier including magnetic core particles and a coating layer, wherein the coating layer is formed by applying a coating liquid containing at least colloidal silica, a condensate of alkoxysilane represented by General Formula (1) and a solvent onto the core particles; an amount of colloidal silica contained in the coating layer is less than 60% by mass; and a ratio (h/Dw) of a thickness (h) of the coating layer to a weight average particle diameter (Dw) of the carrier is more than 0.01, wherein the carrier is used in a two-component developer together with a toner produced through aqueous granulation and containing at least a colorant, a binder resin and a releasing agent, and wherein an amount of the releasing agent present in a region from a surface of the toner to a depth of 0.3 ?m is less than 4% by mass as measured through FTIR-ATR spectroscopy.
    Type: Application
    Filed: February 5, 2009
    Publication date: August 13, 2009
    Inventors: Yoshihiro Moriya, Keishi Taniguchi, Akihiro Kotsugai, Ryota Inoue, Shingo Sakashita
  • Patent number: 7570904
    Abstract: In the image forming apparatus by: visualizing an electrostatic latent image formed on an electrostatic charge carrying member; transferring a toner image, which is thus visualized, to a recording medium, or to a recording medium through an intermediate transfer material; and fixing the toner image, which is thus transferred to the recording medium, to obtain a recorded image, the toner includes at least a fixing resin, a colorant, a releasing agent, and an external additive, the toner has an average particle diameter in a range of from 4 to 12 ?m and including no particle having a diameter of 45 ?m or more, a ratio of a toner adhesion amount in a character part to a toner adhesion amount in a solid image part upon printing is more than 0.5 and less than 4, and the toner adhesion amount in a character part is 1.6 mg/cm2 or less.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: August 4, 2009
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Shigenori Yaguchi, Junji Kobayashi, Hirobumi Ouchi, Tomonari Hokkyo
  • Patent number: 7560214
    Abstract: Toner of the present invention is produced by mixing in an aqueous medium at least a resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed and heating and aggregating the mixed dispersion. The main component of a surface-active agent used for the resin particle dispersion is a nonionic surface-active agent. The main component of at least one surface-active agent selected from a surface-active agent used for the wax particle dispersion and a surface-active agent used for the colorant particle dispersion is a nonionic surface-active agent. With this configuration, the toner can have a smaller particle size and a sharp particle size distribution without requiring a classification process.
    Type: Grant
    Filed: May 16, 2005
    Date of Patent: July 14, 2009
    Assignee: Panasonic Corporation
    Inventors: Yasuhito Yuasa, Hidekazu Arase, Mamoru Soga, Masahisa Maeda
  • Patent number: 7560218
    Abstract: A process for preparing a toner comprising the steps of (1) pulverizing a pulverized product of a composition comprising a resin binder and a colorant with a jet type pulverizer in the presence of fine inorganic oxide particles, to give an upper limit cut-off classification powder; and (2) classifying the upper limit cut-off classification powder with a classifier, the classifier comprising a classifying rotor comprising a driving shaft arranged in one casing as a central shaft thereof in a vertical direction, and a stationary spiral guiding vane arranged to share the same central shaft as the classifying rotor, wherein the stationary spiral guiding vane is arranged in a classification zone on an outer circumference of the classifying rotor with a given spacing to the outer circumference of the classifying rotor.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: July 14, 2009
    Assignee: Kao Corporation
    Inventors: Shinichiro Omatsu, Shunji Arita
  • Patent number: 7547498
    Abstract: A toner for developing electrostatic images which contains an external additive A containing an irregular-shaped metal oxide and having an average value of the feret's horizontal diameter of from 20 nm to 1370 nm, and an external additive B containing a hydrophobic particle having an average value of the feret's horizontal diameter of from 10 nm to 45 nm.
    Type: Grant
    Filed: October 13, 2004
    Date of Patent: June 16, 2009
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Kenji Yamane, Masafumi Uchida, Yasuko Yamauchi
  • Publication number: 20090142682
    Abstract: A toner including a binder resin, a coloring agent, a releasing agent and a modified laminar inorganic mineral, wherein the toner is granulated by dispersing the coloring agent, the releasing agent, the modified laminar inorganic mineral and at least one of the binder resin and a precursor thereof in an organic solvent to form an oil phase, dispersing the oil phase in an aqueous medium to obtain a dispersion emulsion and removing solvents therefrom, and the toner satisfies the following relationship (1): 0.2?{1/Dv (?m)}×Sb (m2/g)?1.4, where Dv represents a volume average particle diameter of the toner, and Sb represents a BET specific surface area of the toner.
    Type: Application
    Filed: December 1, 2008
    Publication date: June 4, 2009
    Inventors: Akinori Saitoh, Osamu Uchinokura, Masahide Yamada, Tomomi Suzuki, Junichi Awamura
  • Patent number: 7539440
    Abstract: The present invention provides a magnetic monocomponent developer which can obtain a stable conveying performance for a long period and an image forming method which uses the developer. In a magnetic monocomponent developer which is used in a developing unit which includes a developing vessel which accommodates a magnetic monocomponent developer therein, a developer carrying body which carries the magnetic monocomponent developer and conveys the magnetic monocomponent developer to a developing region, and a developer layer thickness restricting member which restricts a layer thickness of the magnetic monocomponent developer, the magnetic monocomponent developer includes toner particles which contain at least a binder resin and magnetic powder, and also includes following constitutions (a) to (c). (a) an average particle size of the toner particles may being set to a value which falls within a range from 6 to 9 ?m.
    Type: Grant
    Filed: April 19, 2006
    Date of Patent: May 26, 2009
    Assignee: Kyocera Mita Corporation
    Inventor: Hidekazu Tamura
  • Patent number: 7531281
    Abstract: 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 ?m to 7 ?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 ?m to 2.0 ?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.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: May 12, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Publication number: 20090111040
    Abstract: A pigment particle coated with at least one of a resin and a charge control surface additive, wherein the pigment particle is a pearlescent or metallic pigment. The pigment adds pearlescent effects and is a size and charge as to be used as a toner material in electrostatographic image formation.
    Type: Application
    Filed: October 25, 2007
    Publication date: April 30, 2009
    Applicant: XEROX CORPORATION
    Inventors: Richard P.N. VEREGIN, Karen A. MOFFAT, Michael S. HAWKINS, Cuong VONG, Eric M. STROHM, Wafa Faisul BASHIR, Shigang QIU
  • Publication number: 20090104556
    Abstract: The present invention relates to micron to sub-micron sized coloured polymeric electrophotographic toner particles, a process for making those particles and their use as dry or liquid electrophotographic toners, and as component in the preparation of two-component electrophotographic developers. The particles comprise two different kinds of polymers and are made through dewatering of a water-in-oil emulsion.
    Type: Application
    Filed: November 6, 2006
    Publication date: April 23, 2009
    Inventors: William Grierson, Lee Christina Miller, Kishor Kumar Mistry, Bryan David Grey, Mark Christopher Baxter
  • Patent number: 7522857
    Abstract: The object is to provide a toner which can be smoothly replenished by a toner replenishing device using a powder pump even when the toner contains a releasing agent, and an image forming apparatus using the toner. There is provided a toner, which comprises a binder resin, a colorant and a releasing agent, has a dynamic friction coefficient of 0.15 to 0.35, and is replenished by the toner replenishing device having a powder pump configured to automatically supply the toner and a toner container arranged in conjunction with the powder pump so as to develop a latent electrostatic image on a image bearing member.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: April 21, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Kumi Hasegawa, Mitsuo Aoki, Hyo Shu, Minoru Masuda, Tomoko Utsumi
  • Patent number: 7515860
    Abstract: An image forming apparatus comprising: a latent image support for supporting a latent image and a developing device configured to us toner to develop the latent image on said latent image support, the estimated average halftone granularity of the toner imager after developing being 0.25 or less.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: April 7, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Suzuki, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20090087767
    Abstract: The invention provides a color toner for flash fusing containing at least: a binder resin, a colorant, a leuco dye, a developer and a decolorizer. An absorbance of the color toner after photoirradiation at a wavelength of about 900 nm is smaller than an absorbance of the color toner before the photoirradiation at the wavelength of about 900 nm. The invention further provides a method for producing the color toner, a electrostatic image developer comprising the color toner, a process cartridge comprising a developer bearing body which accommodates the electrostatic image developer, and an image forming apparatus to form a toner image by the electrostatic image developer.
    Type: Application
    Filed: July 14, 2008
    Publication date: April 2, 2009
    Applicant: FUJI XEROX CO., LTD.
    Inventor: Yasushige NAKAMURA
  • Publication number: 20090061343
    Abstract: A toner having its surface functionalized with functional groups, and processes for producing the same, are provided.
    Type: Application
    Filed: September 4, 2007
    Publication date: March 5, 2009
    Inventors: Zhen Lai, Yuhua Tong, Chieh-Min Cheng
  • Patent number: 7498111
    Abstract: Disclosed is an electrophotographic photoreceptor which comprises a layer on a support, wherein the photoreceptor satisfies a condition represented by Formulas 1 and 2; 0<Pmax<2P??Formula 1 2?(Pmax/D)×100?50??Formula 2 wherein P represents an average of the layer thickness in ?m at the central portion in the width direction of image forming area of the support, Pmax represents is an average of the largest value of the layer thickness in ?m without the image forming area, D represents an average of the distance in ?m from the point where the largest value is formed to the edge of the layer and a image forming method and an apparatus using the same.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: March 3, 2009
    Assignee: Konica Minolta Holdings, Inc.
    Inventors: Masao Asano, Hiroshi Yamazaki, Nobuaki Kobayashi
  • Publication number: 20090053640
    Abstract: A toner is obtained in an aqueous medium by dispersing second resin particles into a core particles dispersion including at least first resin particles, and fusing the second resin particles with core particles. A second resin particle dispersion in which the second resin particles are dispersed is added after adjusting the pH value in the range of HS+2 to HS?5, where HS represents the pH value of the core particle dispersion in which the core particles are dispersed, so that toner particles have a volume-average particle size of 3 to 7 ?m, a content of the toner particles having a particle size of 2.52 to 4 ?m in a number distribution is 10 to 75% by number, the toner particles having a particle size of 4 to 6.06 ?m in a volume distribution is 25 to 75% by volume, and the toner particles having a particle size of not less than 8 ?m in the volume distribution is not more than 5% by volume.
    Type: Application
    Filed: February 10, 2006
    Publication date: February 26, 2009
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasuhito Yuasa, Masahisa Maeda
  • Publication number: 20090035683
    Abstract: A toner comprising a small-particle diameter external additive having a number average particle diameter of 7 to 20 nm, a large-particle diameter external additive having a number average particle diameter of 40 to 80 nm and a toner particle having a volume average particle diameter of 4 to 7 ?m, wherein the large-particle diameter external additive is stuck to the surface of the toner particles in a semi-embedded state and has a rate of liberation of 0.1% by weight or less from the surface of the toner particle.
    Type: Application
    Filed: August 1, 2008
    Publication date: February 5, 2009
    Inventors: Tatsuo IMAFUKU, Takahiro Bito, Takeshi Satoh
  • Publication number: 20090035681
    Abstract: A toner or two-component developer is obtained by mixing, aggregating, and heating resin particles, colorant particles, and wax particles in an aqueous medium. A gel permeation chromatography (GPC) measurement of the resin particles shows that a weight-average molecular weight is 10000 to 60000, and the ratio of the weight-average molecular weight to a number-average molecular weight is 1.5 to 6. The wax particles include at least a first wax and a second wax. An endothermic peak temperature (melting point Tmw1 (° C.)) of the first wax based on a DSC method is 50° C. to 90° C. An endothermic peak temperature (melting point Tmw2 (° C.)) of the second wax based on the DSC method is at least 5° C. to 50° C. higher than Tmw1. Thus, the toner can have a smaller particle size and a sharp particle size distribution without requiring a classification process, can achieve a longer life, and can suppress transfer voids or scattering during transfer.
    Type: Application
    Filed: November 11, 2005
    Publication date: February 5, 2009
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Yasuhito Yuasa, Hidekazu Arase, Masahisa Maeda
  • Patent number: 7473508
    Abstract: A toner composition including toner particles including at least a binder resin; and a colorant, wherein the toner composition satisfies at least one of the following relationships (1) and (2): B?14 when 155<A?180; and B?0.6A?79 when 145?A?155,??(1) wherein A represents a shape factor SF-1 of the toner composition and B represents a content of toner particles having a particle diameter not greater than 3 ?m; and B?14 when 0.920?A??0.950; and B?394?400A? when 0.950<A??0.965??(2) wherein A? represents an average circularity of the toner composition and B represents a content of toner particles having a particle diameter not greater than 3 ?m.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: January 6, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Shinichiro Yagi, Shigeru Emoto, Junichi Awamura, Naohito Shimota, Masami Tomita, Toshiki Nanya, Takahiro Honda, Maiko Kondo
  • Publication number: 20090004591
    Abstract: Disclosed is a toner for developing electrostatic image containing toner particles prepared with a method containing a step of: coagulating resin particle A, resin particle B and a colorant, wherein resin particle A and resin particle B respectively have volume average particle diameters Da and Db which are different in value from each other; and Da and Db satisfy the following relationship: 0.05?Db/Da?0.7.
    Type: Application
    Filed: March 6, 2008
    Publication date: January 1, 2009
    Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.
    Inventors: Tsuyoshi UCHIDA, Masahiro ANNO, Yukio HOSOYA, Masaharu SHIRAISHI
  • Publication number: 20080305423
    Abstract: A toner that includes toner base particles including a binder resin and a colorant, wherein the toner base particles have a surface roughness (Ra) of 18 nm to 50 nm and a standard deviation (RMS) of the surface roughness of 0.5 nm to 9.9 nm. A developer, a developing apparatus, a process cartridge, an image forming apparatus, and an image forming method can all use a developer including the toner.
    Type: Application
    Filed: December 26, 2005
    Publication date: December 11, 2008
    Inventors: Hideki Sugiura, Shinya Nakayama
  • Publication number: 20080299475
    Abstract: A developer for development of electrostatic images, comprising colored particles containing a binder resin, a colorant and a parting agent, and an external additive, wherein the developer has properties that a work function is at least 5.70 eV; when excitation energy (eV) in the measurement of the work function is plotted on an axis of abscissa, and a normalized photoelectron yield represented by the 0.5th power of a photoelectron yield per unit photon is plotted on an axis of ordinate, a gradient of the normalized photoelectron yield to the excitation energy is at least 15/eV; and an extraction quantity with methanol is 5.0% by weight or less, and a production process thereof.
    Type: Application
    Filed: August 3, 2005
    Publication date: December 4, 2008
    Applicant: Zeon Corporation,
    Inventor: Hiroto Kidokoro
  • Publication number: 20080286680
    Abstract: A method for manufacturing a toner, including periodically forming liquid droplets of a toner constituent liquid comprising a resin and a colorant by vibrating a thin film having a plurality of holes provided on a retention part thereof to discharge the liquid droplets of the toner constituent liquid from the plurality of holes and forming toner particles by solidifying the liquid droplets discharged from the plurality of holes. In periodically forming the liquid droplets of the toner constituent liquid, a flow of gas in a direction of discharge of the liquid droplets is formed by a gas flow generation unit provided downstream from the thin film relative to the direction of discharge of the liquid droplets, including a tapered part forming an aperture corresponding to a hole formation area of the thin film.
    Type: Application
    Filed: May 15, 2008
    Publication date: November 20, 2008
    Inventors: Yoshihiro Norikane, Shinji Ohtani, Yohichiroh Watanabe, Kazumi Suzuki
  • Publication number: 20080286679
    Abstract: A method of preparing a toner, including periodically dripping and discharging droplets of a toner constituent liquid comprising a resin and a colorant with a dripper comprising a thin film comprising plural nozzles configured to discharge the droplets, and an electromechanical converter configured to oscillate the thin film; and solidifying the droplets to form toner particles, wherein the nozzle has an aperture discharging the droplet, having a circular or an ellipsoidal cross-sectional shape and cross-sectional area smaller than a cross-sectional area of another aperture contacting the toner constituent liquid.
    Type: Application
    Filed: May 14, 2008
    Publication date: November 20, 2008
    Applicant: Ricoh Company, Ltd.
    Inventors: Yoshihiro NORIKANE, Shinji Ohtani, Yohichiroh Watanabe, Kazumi Suzuki, Takahiro Honda
  • Patent number: 7452648
    Abstract: The present invention provides a magnetic mono-component toner which can suppress a selection development on a latent image carrier and can maintain favorable image properties for a long period by using a toner having the coarse powder distribution (S) within a given range in a jumping developing method and an image forming method which uses the toner. In the toner used in the jumping developing method which develops an electrostatic latent image formed on a latent image carrier using a developer carrier, the toner includes toner particles which contain at least a binding resin and a magnetic powder, and the coarse powder distribution (S) of the toner particles satisfies a following formula (1).
    Type: Grant
    Filed: September 23, 2005
    Date of Patent: November 18, 2008
    Assignee: Kyocera Mita Corporation
    Inventor: Hideaki Kawata
  • Patent number: 7449275
    Abstract: A process for preparing a toner including the steps of (I) melt-kneading a raw material mixture containing a resin binder and a colorant; (II) cooling the melt-kneaded mixture obtained in the step (I) and pulverizing the cooled mixture to give a pulverized product having a volume-median particle size (D50v) of from 10 to 1000 ?m; (III) pulverizing the pulverized product obtained in the step (II) in the presence of an external additive having an average particle size of from 8 to 50 nm; and (IV) classifying the pulverized product obtained in the step (III), wherein the resulting toner has a volume-median particle size (D50v) of from 3.5 to 8 ?m, and the total amount of m kind(s) of external additive(s) in the step (III) satisfies a specified formula. The toner can be used, for instance, for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: November 11, 2008
    Assignee: Kao Corporation
    Inventor: Akihiro Eida
  • Patent number: 7449274
    Abstract: A toner for electrostatic image development, which contains toner particles in which not more than 13 percent by number of the toner particles have a particle diameter of smaller than 4 ?m, not less than 20 percent by number of the toner particles have a particle diameter of 4 ?m to 6 ?m, and not more than 2.0 percent by volume of the toner particles have a particle diameter of 16 ?m or greater. The toner particles have a volume average diameter of 4 ?m to 9 ?m, and at least an external additive is added to the toner particles.
    Type: Grant
    Filed: November 1, 2005
    Date of Patent: November 11, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuo Imafuku, Takahiro Bito, Eiji Tenjiku, Takeshi Satoh, Takeshi Ohkawa, Akiko Tsujimoto
  • Publication number: 20080268366
    Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 30, 2008
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Masayuki Ishii, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Hideki Sugiura, Shigeru Emoto, Junichi Awamura, Masami Tomita, Takahiro Honda, Shinichiro Yagi, Tomomi Suzuki, Hiroshi Yamada, Toshiki Nanya, Hiroto Higuchi, Fumihiro Sasaki, Naohito Shimota
  • Patent number: 7442482
    Abstract: A process for preparing a toner including the steps of (I) melt-kneading a raw material mixture containing a resin binder, a wax, and a colorant with an open-roller type kneader; (II) cooling the melt-kneaded mixture obtained in the step (I) and pulverizing the cooled mixture; and (III) classifying the pulverized product obtained in the step (II) to give a toner, wherein the wax is contained in the toner in an amount of from 2 to 15% by weight, and has a number-average particle size in the toner of 1 ?m or less, wherein the toner has a volume-median particle size (D50) of from 3.5 to 7 ?m, and a standard deviation in volume base particle size distribution of ¼ of D50 or less, and contains 5% by volume or less of particles having particle sizes of (1.4×D50) ?m or more, and 5% by number or less of particles having particle sizes of 3 ?m or less.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: October 28, 2008
    Assignee: Kao Corporation
    Inventor: Akihiro Eida
  • Publication number: 20080241727
    Abstract: A method for manufacturing toner includes steps of supplying, periodically dispensing, and solidifying. The supply step supplies a liquid to be atomized, which includes at least a resin and a colorant. The periodic dispensation step periodically dispenses droplets of the liquid through an atomizing unit. The solidification step solidifies the dispensed droplets into toner particles. The atomizing unit includes a thin film, a vibration actuator, and multiple holes. The thin film has a relatively stiff portion and a relatively elastic portion, and is configured to contact the liquid. The vibration actuator is connected to and supports a periphery of the thin film, and is configured to induce vibration of the thin film. The multiple holes are formed in the relatively stiff portion, and are configured to discharge droplets therethrough when the thin film vibrates.
    Type: Application
    Filed: May 13, 2008
    Publication date: October 2, 2008
    Applicant: Ricoh Company, Ltd.
    Inventors: Yoshihiro NORIKANE, Shinji Ohtani
  • Patent number: 7429442
    Abstract: A toner is provided that contains a binder resin; a colorant; a release agent; and an external additive, wherein the toner has an average circularity of from 0.940 to 0.965 and a crater having a depth of from 0.02 to 0.1 ?m, and wherein the crater has an amount of the external additive larger than an average amount thereof on the toner, along with a two-component developer containing the toner and an image forming apparatus using the toner.
    Type: Grant
    Filed: February 22, 2005
    Date of Patent: September 30, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takahiro Honda, Masami Tomita, Toshiki Nanya, Fumihiro Sasaki, Shigeru Emoto, Hiroto Higuchi, Hiroshi Yamada, Shinichiro Yagi, Tomomi Suzuki, Junichi Awamura, Naohito Shimota
  • Publication number: 20080233508
    Abstract: The present invention relates to a process for producing a toner for electrophotography, including: (a) a step of aggregating resin particles containing a resin binder in an aqueous medium; and (b) a step of unifying the aggregated resin particles, the step (a) including: (a-1) a step of adding a monovalent salt as an aggregating agent; and (a-2) a step of adding at least one compound selected from the group consisting of alkylethersulfates represented by the formula (1): R—O—(CH2CH2O)nSO3M ??(1) wherein R is an alkyl group; n represents an average molar number of addition and is a number of more than 0 and not more than 15 (0<n?15), and M is a monovalent cation, alkylsulfates and linear alkylbenzenesulfonates. The toner of the present invention has a small particle size which is controlled with a high accuracy, and a sharp particle size distribution, and a particle shape of the toner is readily controlled even at a low temperature, and further the obtained toner exhibits a high circularity.
    Type: Application
    Filed: September 7, 2007
    Publication date: September 25, 2008
    Applicant: KAO CORPORATION
    Inventors: Nobumichi KAMIYOSHI, Manabu Suzuki, Yutaka Murai
  • Publication number: 20080227018
    Abstract: To provide a toner containing toner particles, wherein each toner particle contains at least: a releasing agent having an average dispersed particle diameter of 0.1 to 0.5 ?m; and a modified layered inorganic mineral in which at least a part of ions present in between layers of a layered inorganic mineral is replaced with an organic ion, wherein the toner has a ratio A/B of 0.2 to 2.0 where A denotes the average dispersed particle diameter of the releasing agent and B denotes an average dispersed particle diameter of the modified layered inorganic mineral, or a proportion of the dispersed particles of the releasing agent having a diameter of 1 ?m or more in the dispersed particles of the releasing agent having a diameter of 0.5 ?m or more is 20% by number or less.
    Type: Application
    Filed: March 12, 2008
    Publication date: September 18, 2008
    Inventors: Junichi Awamura, Osamu Uchinokura, Akinori Saitoh, Masahide Yamada, Tomomi Suzuki
  • Publication number: 20080220348
    Abstract: To provide a toner manufacturing method including: continuously mixing an oil phase with an aqueous phase to form an emulsified liquid using an emulsifying mechanism having an emulsified liquid circulation pathway and an emulsifying device equipped with a stirring blade; forming liquid droplets from the emulsified liquid by controlling the equilibrium between atomization and integration of the liquid droplets; and feeding the liquid droplets with stirring to a series of treatments including at least desolvation, filtration, washing and drying; wherein a product T of the solid content concentration (% by mass) of the oil phase and viscosity (mPa·s) measured with a rotating viscometer at 25° C., and 6 rpm satisfies 30,000?T?50,000.
    Type: Application
    Filed: March 6, 2008
    Publication date: September 11, 2008
    Inventors: Shinzo Higuchi, Hiroshi Takahashi
  • Publication number: 20080213684
    Abstract: To provide a carrier for electrophotographic developer including core particles and a cover layer covering the particles, wherein at least one of the carrier to be supplied in a developing apparatus and carrier contained in the developing apparatus has a weight average particle diameter Dw of 22 ?m or more and 32 ?m or less, a ratio Dw/Dp of the weight average particle diameter Dw to the number average particle diameter Dp that satisfies the relationship 1.00?Dw/Dp?1.20, particles whose particle diameter x (?m) is within a range of 0<x<20 in an amount of 7 wt % or less, and particles whose particle diameter y (?m) is within a range of 0<y<36 in an amount of 90 wt % or more and 100 wt % or less.
    Type: Application
    Filed: January 16, 2008
    Publication date: September 4, 2008
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Patent number: 7419756
    Abstract: A dry toner contains fine particles having average sphericity of 0.93 to 0.99, a content of the fine particles having a particle diameter of 2 ?m or less in the dry toner is 20% by number or less. A method for manufacturing a dry toner includes a process for dispersing in an aqueous medium containing water and a water-soluble organic solvent, a toner composition contained in an organic solvent by using fine solid dispersing agent; and a process for contracting volume of the dispersed toner composition. Further, the image forming apparatus having a photoconductor; a charger for charging the photoconductor; a light irradiator for irradiating the electrophotographic photoconductor to form a latent electrostatic image; a developer for developing the latent electrostatic image to form a developed image; and a transfer for transferring the developed image to a recording material, and the developer contains the dry toner abovementioned.
    Type: Grant
    Filed: April 13, 2007
    Date of Patent: September 2, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Yamashita, Chiaki Tanaka, Tsunemi Sugiyama, Hiroshi Yamada, Kazuhito Watanabe, Shigeru Emoto, Masami Tomita
  • Publication number: 20080187856
    Abstract: The present invention relates to controlling the mass flow of toner in an image forming device or a toner cartridge. The toner composition includes extra particulate additives including a conductive additive. The extra particulate additives may also include relatively small silica particles or relatively large silica.
    Type: Application
    Filed: February 1, 2007
    Publication date: August 7, 2008
    Inventors: Scott Moreland Broce, Robert Joseph Firmature, Yueping Fu, Matthew David Heid, Lance Tisdale Hoshiko, James Craig Minor, Karen Eileen Zrebiec
  • Publication number: 20080187857
    Abstract: A toner for electrophotography satisfies Ft/Dt?3.0 [nN/?m], where Ft is an inter-toner non-electrostatic adhesion force after a compressive stress within 0.7×10?2 [N m2] to 1.5×10?2 [N/m2] is applied, and Dt is a diameter of a toner particle. The inter-toner non-electrostatic adhesion force is obtained by filling a two-dividable cell for an Agrobot AGR manufactured by Hosokawa Micron Corporation having a diameter of 15 mm, measuring a tensile rupture stress required for dividing the cell after a compressive stress is applied, and substituting the tensile rupture stress into Rumpf's equation.
    Type: Application
    Filed: November 29, 2007
    Publication date: August 7, 2008
    Inventors: Yasuhiko OGINO, Takeo Yamaguchi, Masami Kadonaga
  • Publication number: 20080182191
    Abstract: An emulsion aggregation toner having toner particles comprising a gel latex, a high Tg latex and at least one wax, wherein the toner fuses at about 170° C. to about 220° C. at process speeds of from about 560 mm/s to about 870 mm/s, wherein the toner exhibits a crease fix property of less than about 60 and a half-toner rub fix property of less than about 0.15. The toner exhibits excellent half-tone rub fix performance and crease fix at high print speeds.
    Type: Application
    Filed: January 31, 2007
    Publication date: July 31, 2008
    Applicant: XEROX CORPORATION
    Inventors: Karen A. MOFFAT, Edward G. ZWARTZ, T. Brian MCANENEY, Fernando P. YULO
  • Publication number: 20080176163
    Abstract: The present invention provides a toner having: a toner mother particle; a first external additive including a first inorganic fine particle having a primary particle size distribution of 200 to 750 nm and a work function approximately equivalent to that of the toner mother particle; a second external additive including a second inorganic fine particle having an mean particle size smaller than that of the first inorganic fine particle and a work function smaller than that of the toner particle, a stirring member of a developing device and/or an inner wall of the developing device; and 0.01% to 0.3% by weight of a metal soap having a work function approximately equivalent to that of the toner mother particle.
    Type: Application
    Filed: March 13, 2008
    Publication date: July 24, 2008
    Applicant: Seiko Epson Corporation
    Inventors: Nobuhiro MIYAKAWA, Shinji Yasukawa, Hiroyuki Murakami
  • Patent number: 7402370
    Abstract: A toner for developing electrostatic images in a single component development (SCD) system free of carrier and including emulsion aggregation toner particles of a styrene acrylate polymer binder, at least one release agent and at least one colorant, wherein the toner particles have a volume average particle size of from about 5 ?m to about 10 ?m, an average circularity of about 0.95 to about 0.99, a volume and number geometric standard deviation (GSDv and n) of from about 1.10 to about 1.30, and an onset glass transition temperature of from about 45° C. to about 65° C., is ideally suited for forming an image using a single component image forming device.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: July 22, 2008
    Assignee: Xerox Corporation
    Inventors: Grazyna E Kmiecik-Lawrynowicz, Maura A Sweeney, Daniel W Asarese, Eunhee Lee, Robert D Bayley
  • Patent number: 7399567
    Abstract: A toner for electrostatic latent image development containing at least a binder resin and a colorant, wherein [Fe]/[C] satisfies the following formula (1) where [C] indicates the carbon content (%) and [Fe] indicates the iron content (%) of the toner determined through X-ray fluorescence analysis, 0.00005?[Fe]/[C]?0.0002.
    Type: Grant
    Filed: June 10, 2005
    Date of Patent: July 15, 2008
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yasuo Kadokura, Masakazu Iijima, Tomohito Nakajima, Satoshi Yoshida, Michio Take, Takao Ishiyama
  • Publication number: 20080160443
    Abstract: Toner of the present invention is produced by mixing in an aqueous medium at least a resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed and heating and aggregating the mixed dispersion. The main component of a surface-active agent used for the resin particle dispersion is a nonionic surface-active agent. The main component of at least one surface-active agent selected from a surface-active agent used for the wax particle dispersion and a surface-active agent used for the colorant particle dispersion is a nonionic surface-active agent. With this configuration, the toner can have a smaller particle size and a sharp particle size distribution without requiring a classification process.
    Type: Application
    Filed: May 16, 2005
    Publication date: July 3, 2008
    Applicant: Matsushita Electric Industrical Co.,Ltd.
    Inventors: Yasuhito Yuasa, Hidekazu Arase, Mamoru Soga, Masahisa Maeda
  • Publication number: 20080138735
    Abstract: 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 ?m to 7 ?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 ?m to 2.0 ?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.
    Type: Application
    Filed: October 31, 2007
    Publication date: June 12, 2008
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7384720
    Abstract: 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 ?m to 7 ?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 ?m to 2.0 ?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.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7378213
    Abstract: A process contains in which heating and fixing an image of a toner on a recording medium is performed by heating one or more heat-transfer media by a heating element, and pressing the recording medium bearing the toner image to one of the heat-transfer media. At least one of the heat-transfer media is a belt heat-transfer medium with or without the application of an oil whose amount is 4 mg or less per A4 size, and the toner contain a binder resin and a releasing agent, has a weight-average particle diameter Dv of 3.0 to 7.0 ?m, a particle diameter distribution Dv/Dn of 1.00 or more and 1.25 or less, wherein Dn is a number-average particle diameter, and an average shape factor SF-1 of 100 to 150 and contains toner particles having a shape factor SF-1 of 160 or more in an amount of 10% by number or less.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: May 27, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Hiroaki Matsuda
  • Patent number: 7374854
    Abstract: The present invention provides an image-forming method, including pseudo-halftone-processing an input signal corresponding to image information to generate an output signal; irradiating a radiation beam corresponding to the output signal onto a latent image-holding member to form a latent image; developing the latent image with a developer including a toner containing a binder resin and a colorant to form a toner image on the latent image-holding member; transferring the toner image onto a recording medium; and fixing the toner image on the recording medium to form an image, wherein: when a halftone image is formed as the image, the toner image formed on the latent image-holding member is composed of plural toner aggregates scattered like dots on the latent image-holding member; the diameter of the radiation beam irradiated onto the latent image-holding member is 35 ?m or more; the pseudo-halftone processing results in the toner aggregates, which have been transferred onto the recording medium, having uneven
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: May 20, 2008
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masanobu Ninomiya, Hiroshi Nakazawa, Takao Ishiyama, Toshiyuki Yano
  • Patent number: 7374848
    Abstract: A toner including a binder; a colorant; and a wax, wherein the binder includes a polyester resin; and a reaction product of a polymer having a group capable of reacting with an active hydrogen with a compound having an active hydrogen, wherein the polyester resin includes tetrahydrofuran(THF)-soluble resin components in an amount of from 50 to 85% by weight; and chloroform-insoluble components in an amount of from 0 to 30% by weight, and wherein the toner satisfies the following relationship (1): 5% by weight<(C1-C2)<60% by weight ??(1) wherein C1 represents a content of chloroform-insoluble components in the toner in units of % by weight and C2 represents a content of the colorant therein in units of % by weight.
    Type: Grant
    Filed: June 22, 2004
    Date of Patent: May 20, 2008
    Assignee: Ricoh Company, Limited
    Inventors: Sonoh Matsuoka, Ryohta Inoue, Masahiro Ohki, Takeshi Takada, Chiaki Tanaka, Naohiro Watanabe, Masahide Yamada
  • Publication number: 20080107992
    Abstract: An image forming method of forming an image by transferring a toner image, which is formed on an image bearing member by toner particles, to a transfer medium is provided. The toner particles include a coloring agent and a resin. When an average electrostatic adhesive force Fe of the toner particles to the image bearing member is expressed by the following expression, a/r satisfies 0.2?a/r?0.7: F e = ? ? - 1 ? ? + 1 · q 2 ? r 2 4 ? ?? 0 ? ( r 2 - a 2 ) 2 where ?? is a specific dielectric constant of the image bearing member, q is an electrification quantity per one toner particle, and r is a volume average radius of the toner particles.
    Type: Application
    Filed: November 7, 2007
    Publication date: May 8, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventor: Shoko Shimmura
  • Publication number: 20080102398
    Abstract: A method for producing a developing agent including heating a dispersion of a toner particle material containing a binder resin fine particle, a coloring agent particle and a dispersion medium at a temperature of a glass transition point of the binder resin or higher and adding a coagulating agent in the heated dispersion of a toner particle material to coagulate a toner material containing the binder resin fine particle and the coloring agent particle, thereby forming a coagulated particle is disclosed.
    Type: Application
    Filed: October 26, 2007
    Publication date: May 1, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takayasu Aoki, Masahiro Ikuta, Tsuyoshi Itou, Takashi Urabe, Motonari Udo, Satoshi Araki