Patents by Inventor Akihiro Kotsugai

Akihiro Kotsugai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080280219
    Abstract: The present invention provides a toner containing at least a binder resin, a releasing agent, and a colorant, wherein the binder resin contains at least a polyester resin (A) having a softening point Tm(A) of 120° C. to 160° C., a polyester resin (B) having a softening point Tm(B) of 80° C. or more and less than 120° C. and a composite resin (C) containing a condensation polymerization monomer and an addition polymerization monomer, at least any one of the polyester resins (A) and (B) is a polyester resin prepared by condensation-polymerizing an alcohol component substantially composed of only aliphatic alcohol with a carboxylic acid component, and 65% or more of the alcohol component is 1,2-propanediol.
    Type: Application
    Filed: May 9, 2008
    Publication date: November 13, 2008
    Inventors: Shinya Nakayama, Akihiro Kotsugai, Akiyoshi Sabu, Hiroshi Yamashita, Hiroshi Yamada, Junichi Awamura, Tsuyoshi Sugimoto
  • Publication number: 20080280218
    Abstract: To provide a toner produced by emulsifying or dispersing in an aqueous medium particles containing at least polyester resin particles and by aggregating the polyester resin particles, wherein the polyester resin particles contain a polyester resin, the polyester resin is produced by condensation polymerization of an alcohol component containing 65 mol % or more 1,2-propanediol in a dihydroxy alcohol component and a carboxylic acid component containing purified rosin, and the softening point of the polyester resin is 80° C. or more and less than 120° C., and wherein the toner comprises a colorant and a releasing agent.
    Type: Application
    Filed: April 30, 2008
    Publication date: November 13, 2008
    Inventors: Akiyoshi Sabu, Akihiro Kotsugai, Shinya Nakayama, Hiroshi Yamashita, Tsuyoshi Sugimoto, Hiroshi Yamada, Junichi Awamura
  • 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: 7442484
    Abstract: An image forming method including: forming a toner image on a support using a toner including toner particles; and feeding the support bearing the toner image thereon through a nip between an endless toner heating member and a pressure roller to fix the toner image on the support, wherein the endless toner heating member is rotated while stretched by a fixing roller and a heat roller which includes a magnetic metal and which is heated by electromagnetic induction, and wherein the pressure roller presses the support to the endless toner heating member and the fixing roller at the nip, wherein the toner particles are prepared by a polymerizing method using a binder resin containing at least a modified polyester resin.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: October 28, 2008
    Assignee: Ricoh Company Limited
    Inventors: Osamu Uchinokura, Akihiro Kotsugai, Yasuo Asahina, Tomoyuki Ichikawa, Shinya Nakayama, Kohichi Sakata, Tomoko Utsumi, Hisashi Nakajima, Yasuaki Iwamoto, Hideki Sugiura, Satoshi Mochizuki
  • Publication number: 20080261131
    Abstract: A toner that is excellent in low-temperature fixing property, offset resistance, storage stability, charge rising property, charge stability with time and pulverizability and allows for forming high-quality images over a long period of time. The toner contains at least a binder resin, a colorant and a charge controlling agent, wherein the charge controlling agent contains an aromatic oxycarboxylic acid metal compound having a trivalent or more central metal, the binder resin comprises a polyester resin (A) having a softening point Tm (A) of 120° C. to 160° C. and a polyester resin (B) having a softening point Tm (B) of 80° C. to less than 120° C., and at least any one of the polyester resins (A) and (B) contains 1,2-propane diol at 65 mol % or more in a divalent alcohol component and can be obtained by condensation polymerizing an alcohol component substantially composed of only an aliphatic alcohol with a carboxylic acid component.
    Type: Application
    Filed: November 21, 2007
    Publication date: October 23, 2008
    Inventors: Shinya NAKAYAMA, Akihiro KOTSUGAI, Yasuaki IWAMOTO, Yasutada SHITARA
  • Publication number: 20080233496
    Abstract: The present invention provides a toner which, despite its spherical shape, makes it possible to prevent an external additive from being embedded in the toner easily or by a load generating low stress, reduce variation in image density, maintain cleaning ability and transfer ability throughout its long-term use and obtain excellent image quality, and further, provides a two-component developer, an image forming method and an image forming apparatus with the use of the toner. There is a toner including: base particles including a colorant and a resin, and hard fine particles, wherein the base particles and the hard fine particles are mixed together, and protruding portions formed of fine organic resin particles which are different in composition from a resin contained as a main component in the base particles are provided on surfaces of the base particles.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 25, 2008
    Inventors: Akihiro KOTSUGAI, Hiroshi Yamashita
  • Publication number: 20080227002
    Abstract: To provide a toner including a binder resin and colorant and is granulated in aqueous medium, wherein the binder resin is a polymer having a polyester skeleton, the polyester skeleton is obtained by block copolymerization of a polyester skeleton A in which at least a constituent unit in which CH3—C*—H(—OH)(COOH) is dehydration condensed is contained in a repeated structure and a polyester skeleton B in which a constituent unit in which CH3—C*—H(—OH)(COOH) is dehydration condensed is not contained in a repeated structure, and an optical isomer ratio X (%) (monomer equivalent) is 80% or less, where the optical isomer ratio X (%)=|X (L-type)?X (D?type)| where X (L-type) denotes a ratio (%) of L-type (lactic acid monomer equivalent) and X (D-type) denotes a ratio (%) of D-type (lactic acid monomer equivalent)) in the constituent unit where CH3—C*—H(—OH)(COOH) is dehydration condensed.
    Type: Application
    Filed: March 14, 2008
    Publication date: September 18, 2008
    Inventors: Yoshihiro Moriya, Hiroshi Yamashita, Akihiro Kotsugai, Shinya Nakayama, Tsuyoshi Sugimoto, Akiyoshi Sabu
  • Publication number: 20080118855
    Abstract: Provided is a toner that comprises a binder resin, a releasing agent, and a colorant, wherein the mass average particle diameter of the toner is 3 ?m to 8 ?m, the content of particles having a particle diameter of no more than 5 ?m is from 60% by number to 90% by number, the binder resin comprises a polyester resin (A) having a softening temperature Tm(A) from no lower than 120° C. to no higher than 160° C. and a polyester resin (B) having a softening temperature Tm(B) from no lower than 80° C. to lower than 120° C., and at least one of the polyester resins (A) and (B) is prepared by condensation polymerization between an alcohol component and a carboxylic acid component, and the alcohol component comprises divalent alcohol of 1,2-propanediol in a content of no less than 65% by mole and consists substantially of aliphatic alcohol; and also provided is a developer that comprises the toner and a carrier.
    Type: Application
    Filed: November 21, 2007
    Publication date: May 22, 2008
    Inventors: Shinya Nakayama, Akihiro Kotsugai, Yasuaki Iwamoto, Yasutada Shitara, Yohichiroh Watanabe
  • Patent number: 7374851
    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: Grant
    Filed: March 20, 2006
    Date of Patent: May 20, 2008
    Assignee: Ricoh Company, Ltd.
    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: 7368213
    Abstract: A toner containing toner particles having a core-shell structure containing a binder resin, a colorant and a release agent. The toner particles are prepared by dissolving or dispersing at least one of the binder resin and a precursor thereof in an organic solvent or a polymeric monomer and reacting the resultant in an aqueous medium for reaction, wherein the toner satisfies the following relationship: ?Tm=Tm1?Tm2>10 ° C., wherein Tm1 represents half efflux temperature of the toner and Tm2 represents half efflux temperature of a toner which is prepared by melting and kneading the toner particles and wherein a content of the release agent existing close to the surface portion of the toner particles is from 7 to 30% by volume based on an entire portion close to the surface portion of the toner particles when the content is determined by Fourier Transform Infrared Spectroscopy Attenuated Total Reflection (FTIR-ATR) method.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: May 6, 2008
    Assignee: Ricoh Company, Limited
    Inventors: Shinya Nakayama, Fumihiro Sasaki, Satoshi Mochizuki, Akihiro Kotsugai, Yasuo Asahina, Osamu Uchinokura, Hisashi Nakajima, Sonoh Matsuoka, Takuya Saito, Tomoyuki Ichikawa, Koichi Sakata
  • Patent number: 7368212
    Abstract: A toner for developing an electrostatic image, includes: a colorant; and a binder resin. The toner has a particle including at least one pore having a diameter of 10 nm or over, and a porosity thereof is in a range from 0.01 to 0.60.
    Type: Grant
    Filed: June 25, 2004
    Date of Patent: May 6, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Shinya Nakayama, Tomoyuki Ichikawa, Koichi Sakata, Tomoko Utsumi, Hisashi Nakajima
  • Patent number: 7320852
    Abstract: A carrier for use with a toner as a two-component type developer for developing an electrostatic image, comprising spherical magnetic core particles, and a resin layer covering each of said core particles and containing at least two resistance controlling materials having different specific resistances, wherein each of the resistance controlling materials is in the form of particles having a number average particle diameter of no more than 1/10 of a number average particle diameter of the toner.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: January 22, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Kotsugai, Kimitoshi Yamaguchi, Naoki Imahashi, Hiroaki Takahashi
  • Publication number: 20080014527
    Abstract: To provide a toner that can provide long-term removability and high-definition images with reduced image layer thickness and densely-packed toner particles, a developer capable of forming high-quality images using the toner, a toner container for containing the toner, a process cartridge using the toner, an image forming apparatus using the toner, and an image forming method using the toner. The toner of the present invention is a toner having a substantially spherical shape with irregularities on its surface and containing at least a binder resin and a colorant, wherein a surface factor SF-1 that represents the sphericity of toner particles is 105 to 180, a surface factor SF-2 that represents the degree of surface irregularities of the toner particles is correlated with the volume-average diameter of the toner particles, and the toner particles have an inorganic oxide particle-containing layer within 1 ?m from their surfaces.
    Type: Application
    Filed: July 13, 2007
    Publication date: January 17, 2008
    Inventors: Akihiro Kotsugai, Satoshi Mochizuki, Hisashi Nakajima, Yasuo Asahina, Osamu Uchinokura, Masayuki Ishii, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto, Hideki Sugiura, Masami Tomita
  • Patent number: 7318989
    Abstract: To provide a toner that can provide long-term removability and high-definition images with reduced image layer thickness and densely-packed toner particles, a developer capable of forming high-quality images using the toner, a toner container for containing the toner, a process cartridge using the toner, an image forming apparatus using the toner, and an image forming method using the toner. The toner of the present invention is a toner having a substantially spherical shape with irregularities on its surface and containing at least a binder resin and a colorant, wherein a surface factor SF-1 that represents the sphericity of toner particles is 105 to 180, a surface factor SF-2 that represents the degree of surface irregularities of the toner particles is correlated with the volume-average diameter of the toner particles, and the toner particles have an inorganic oxide particle-containing layer within 1 ?m from their surfaces.
    Type: Grant
    Filed: August 3, 2006
    Date of Patent: January 15, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Kotsugai, Satoshi Mochizuki, Hisashi Nakajima, Yasuo Asahina, Osamu Uchinokura, Masayuki Ishii, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto, Hideki Sugiura, Masami Tomita
  • Patent number: 7258959
    Abstract: The object of the present invention is to provide a developer having a sharp charge amount distribution and bringing out high-quality image without substantially smearing a charging unit, developing units, a photoconductor, and an intermediate transferring member by the developer, namely, a developer capable of providing an appropriate image density and exhibiting extremely little background smear even when used over a long period of time and repeatedly used for a number of sheets of paper as well as to provide an image forming apparatus for electrophotography using the developer.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: August 21, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Kazuhiko Umemura, Hideki Sugiura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Akihiro Kotsugai, Osamu Uchinokura, Masayuki Ishii
  • Publication number: 20070190444
    Abstract: Toners, developers, toner-containing containers, process cartridges, image forming apparatuses and image forming processes are provided that may maintain proper transfer ability and cleaning property for long period, exhibit less image fluctuation, and represent less embedding of external additives even under stirring the developer at use, and also afford stable flowability and charging ability for long period. The toner of the present invention comprises toner base particles and secondary agglomerates, wherein the toner base particles comprise a toner material that comprises a colorant and a binding resin, and the secondary agglomerates, which being formed of fine particles, each have a secondary particle diameter of no less than 10 ?m.
    Type: Application
    Filed: February 12, 2007
    Publication date: August 16, 2007
    Inventors: Akihiro Kotsugai, Fumihiro Sasaki, Shinya Nakayama, Koichi Sakata
  • Publication number: 20070141500
    Abstract: A toner is provided including a colorant; a first binder resin; and a second binder resin, wherein an amount of the first binder resin and an amount of the second binder resin are phase separated from each other in the toner, and wherein a phase of the first binder resin is partially or completely covered with a phase of the second binder resin; and a method of preparing the toner, and a developer, an image forming method, an image forming apparatus, and a process cartridge using the toner.
    Type: Application
    Filed: December 15, 2006
    Publication date: June 21, 2007
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Ryota Inoue, Yoshihiro Moriya, Shinichi Wakamatsu, Akihiro Kotsugai
  • Patent number: 7192679
    Abstract: The present invention relates to a carrier for electrophotographic developers, a developer containing the carrier, a container for the developer, a image forming apparatus using the developer, an image forming method using the same, and a method of making the carrier.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: March 20, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Kimitoshi Yamaguchi, Naoki Imahashi, Akihiro Kotsugai, Hiroaki Takahashi
  • Publication number: 20070059063
    Abstract: To provide an image forming method including forming a latent electrostatic image on a latent electrostatic image bearing member, developing the latent electrostatic image using a toner to form a visible image, transferring the visible image to a recording medium, and fixing a transfer image transferred on the recording medium, wherein the toner includes a toner base particle containing at least a binder resin, a colorant and an inorganic fine particle, and a charge control agent; and wherein the condition Xsurf>Xtotal is satisfied (where Xsurf is an average proportion of the inorganic fine particles in a near-surface region of the toner base particle, Xtotal is an average proportion of inorganic fine particles in the whole toner base particle.
    Type: Application
    Filed: September 12, 2006
    Publication date: March 15, 2007
    Inventors: Shinya Nakayama, Hisashi Nakajima, Hideki Sugiura, Fumihiro Sasaki, Akihiro Kotsugai, Satoshi Mochizuki
  • Publication number: 20070031748
    Abstract: To provide a toner that can provide long-term removability and high-definition images with reduced image layer thickness and densely-packed toner particles, a developer capable of forming high-quality images using the toner, a toner container for containing the toner, a process cartridge using the toner, an image forming apparatus using the toner, and an image forming method using the toner. The toner of the present invention is a toner having a substantially spherical shape with irregularities on its surface and containing at least a binder resin and a colorant, wherein a surface factor SF-1 that represents the sphericity of toner particles is 105 to 180, a surface factor SF-2 that represents the degree of surface irregularities of the toner particles is correlated with the volume-average diameter of the toner particles, and the toner particles have an inorganic oxide particle-containing layer within 1 ?m from their surfaces.
    Type: Application
    Filed: August 3, 2006
    Publication date: February 8, 2007
    Inventors: Akihiro Kotsugai, Satoshi Mochizuki, Hisashi Nakajima, Yasuo Asahina, Osamu Uchinokura, Masayuki Ishii, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto, Hideki Sugiura, Masami Tomita