Patents by Inventor Yasuaki Iwamoto

Yasuaki Iwamoto 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).

  • Patent number: 7713672
    Abstract: To provide an image forming apparatus including a latent electrostatic image bearing member; a charging unit; an exposing unit; a developing unit; a transferring unit; and a fixing unit, wherein the binder resin of a toner comprises a polyester-based resin (A) and a polyester-based resin (B) having a melting point which is at least 10° C. higher than that of the polyester-based resin (A), the polyester-based resins (A) is a resin which is derived from a (meth)acrylic acid-modified rosin and which has a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a (meth)acrylic acid-modified rosin, and the polyester-based resin (B) is a resin derived from a fumaric acid/maleic acid-modified rosin and has a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing any one of a fumaric acid-modified rosin and a maleic acid-modified rosin.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: May 11, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Yohichiroh Watanabe, Yasuaki Iwamoto, Yasutada Shitara
  • Patent number: 7642032
    Abstract: A toner including a binder resin; and a colorant, wherein a hexafluoroisopropanol (HFIP)-soluble component satisfies the following relationship: 2,000 ?Mn ?7,000 and 1.5 ?Mn/Mw ?10 wherein Mn represents a number-average molecular weight and Mw represents a weight-average molecular weight.
    Type: Grant
    Filed: October 7, 2004
    Date of Patent: January 5, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Akihiro Kotsugai, Yasuo Asahina, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Shinya Nakayama, Kohichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto
  • Publication number: 20090297973
    Abstract: The present invention provides a toner which includes at least a binder resin, and a colorant, wherein the toner has a concentration of radioactive carbon isotope C-14 of 10.8 pMC or higher.
    Type: Application
    Filed: May 22, 2009
    Publication date: December 3, 2009
    Inventors: Yasuaki Iwamoto, Shinya Nakayama, Yasutada Shitara, Hiroyuki Kishida
  • Patent number: 7566521
    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: July 13, 2007
    Date of Patent: July 28, 2009
    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
  • Publication number: 20090175658
    Abstract: To provide an image forming apparatus including: a latent electrostatic image bearing member; a charging unit configured to charge the surface of the latent electrostatic image bearing member; an exposing unit configured to expose the charged surface of the latent electrostatic image to form a latent electrostatic image thereon; a developing unit configured to develop the latent electrostatic image with a toner to form a visualized image; a transferring unit configured to transfer the visualized image onto a recording medium; and a fixing unit configured to fix the visualized image transferred onto the recording medium, wherein the toner includes a binder resin and a coloring agent, and the binder resin includes a polyester resin obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a (meth)acrylic acid modified rosin.
    Type: Application
    Filed: April 20, 2007
    Publication date: July 9, 2009
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yasuaki Iwamoto, Yohichiroh Watanabe, Yasutada Shitara
  • Publication number: 20090155706
    Abstract: An image forming apparatus including a fixing device to fix a toner image on a recording medium including a heat roller and an oil applicator to apply a silicone oil to the heat roller, having a system speed of from 500 to 1700 mm/sec, and using a toner including a binder resin including a crystalline polyester resin and an amorphous polyester resin; a fatty acid amide compound; and a colorant, wherein a ratio (W/R) of a height (W) of a peak at a wavenumber of 1638 cm?1, specific to the fatty acid amide compound, to a height (R) of a peak at a wavenumber of 829 cm?1, specific to the amorphous polyester resin, is from 0.010 to 0.040 in an absorption spectrum obtained by an ATR method (total reflectance method) using a Fourier transform infrared (FT-IR) spectrophotometer.
    Type: Application
    Filed: December 14, 2007
    Publication date: June 18, 2009
    Inventors: Hyo Shu, Minoru Masuda, Yasuaki Iwamoto, Yasutada Shitara
  • Patent number: 7547497
    Abstract: A toner which is negatively charged to develop an electrostatic latent image is provided that contains a colorant; and a binder resin, wherein the toner has an acid value of from 5 to 20 mg KOH/g and an amine value of from 0.5 to 10 mg KOH/g.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: June 16, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Osamu Uchinokura, Masami Tomita, Hisashi Nakajima, Shinya Nakayama, Koichi Sakata, Akihiro Kotsugai, Tomoyuki Ichikawa, Yasuo Asahina, Hideki Sugiura, Yasuaki Iwamoto, Satoshi Mochizuki
  • Publication number: 20090142677
    Abstract: An image forming method including electrostatic image forming step, developing step, transferring step, fixing step and oil application step for applying an oil to a fixing member, wherein the toner includes a binder resin, a colorant and a wax, and the relationship (A2/A1)×100<200 is satisfied, wherein A1 represents the area of the oil dropped on a pellet of the toner measured 30 seconds after dropping the oil, and A2 represents the area of the dropped oil measured 24 hours after dropping the oil. Alternatively, the relationships (X1?X2)<0.5 atomic percent, X1>1.0 atomic percent, and X2>1.0 atomic percent, are satisfied, wherein X1 and X2 represent amounts of Si atoms of the silicone oil measured by subjecting the toner image to X-ray photoelectron spectroscopy at times 5 minutes and 24 hours, respectively, after fixing the toner image.
    Type: Application
    Filed: December 4, 2007
    Publication date: June 4, 2009
    Inventors: Yasutada SHITARA, Minoru MASUDA, Yasuaki IWAMOTO, Hyo SHU
  • Patent number: 7521164
    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 31, 2008
    Date of Patent: April 21, 2009
    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
  • Publication number: 20090075195
    Abstract: A toner is provided including a mother toner including a crystalline polyester resin, an amorphous resin, and a wax, and an external additive in an amount of from 0.30 to 0.55 parts by weight based on 100 parts by weight of the mother toner. The toner satisfies the following equation 0.36?(2.77×C/R+1.97×W/R)/X?1.85, wherein each of C, W, and R represents a height of an absorbance peak specific to the crystalline polyester resin, the wax, and the amorphous resin, respectively, measured by a FT-IR ATR method, and X represents an amount (parts by weight) of the external additive. An image forming method and apparatus using the toner are also provided.
    Type: Application
    Filed: September 15, 2008
    Publication date: March 19, 2009
    Inventors: Hyo SHU, Yasuaki Iwamoto, Yasutada Shitara, Minoru Masuda
  • 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
  • Patent number: 7413838
    Abstract: An external additives for electrophtographic toner comprising finely divided oxide particulate including a silicon compound and a compound for doping said oxide particulate, wherein particle diameter of the primary particle of said finely divided oxide particulate is in the range of 30 nm to 150 nm, and the primary particle of said finely divided oxide particles is substantially spherical shape having the roundness in the range of 0.95 to 0.996, is provided. And this external additives is capable of evading from the embedding of external additives into toner even if after the toner is held in the storage under the condition of high temperature and high humidity, thereby the additives is capable of showing sufficient functions as fluidizing agent and charge supplement agent, and is capable of inhibiting an abnormal charge elevation even after being stored under the low temperature and low humidity.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: August 19, 2008
    Assignee: RICOH Company, Ltd.
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Kazuhiko Umemura
  • Patent number: 7405000
    Abstract: 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 ?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 ?m thick and has a thickness that is ½ 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.
    Type: Grant
    Filed: July 14, 2004
    Date of Patent: July 29, 2008
    Assignees: Sanyo Chemical Industries, Ltd, Ricoh Company, Ltd.
    Inventors: Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro, Yutaka Yoshida, Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura
  • 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: 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
  • Publication number: 20080063971
    Abstract: A method for manufacturing a toner, including: dissolving or dispersing toner constituents including a resin, a colorant, a release agent, and a graft polymer including a polyolefin resin unit and a vinyl resin unit in a solvent, to prepare a toner constituent liquid; supplying the toner constituent liquid to a retention part configured to retain the toner constituent liquid; discharging the toner constituent liquid from the retention part to a granulation space through plural holes arranged on the retention part, while exciting the toner constituent liquid by a vibration means in contact with a part of the retention part, so that the discharged columnar toner constituent liquid is constricted to form liquid droplets; and converting the liquid droplets into solid toner particles; together with a toner manufactured by the above method.
    Type: Application
    Filed: September 7, 2007
    Publication date: March 13, 2008
    Inventors: Yohichiroh WATANABE, Shinji Ohtani, Yoshihiro Norikane, Yasuaki Iwamoto, Yasutada Shitara, Kazumi Suzuki, Takahiro Honda
  • 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