Patents by Inventor Akiyoshi Sabu

Akiyoshi Sabu 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: 20120295188
    Abstract: A resin for use in toner is provided. The resin comprises an oligomer segment and a soft segment. The oligomer segment comprises a polyhydroxycarboxylic skeleton and an aromatic diol skeleton.
    Type: Application
    Filed: May 15, 2012
    Publication date: November 22, 2012
    Inventors: Yukiko NAKAJIMA, Masahide YAMADA, Taichi NEMOTO, Yoshihiro MORIYA, Yoshitaka YAMAUCHI, Keiji MAKABE, Daiki YAMASHITA, Akiyoshi SABU
  • Publication number: 20120231383
    Abstract: A resin for toner containing a polyhydroxy carbonate skeleton and a rigid skeleton.
    Type: Application
    Filed: March 7, 2012
    Publication date: September 13, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hideyuki SANTO, Shinya NAKAYAMA, Atsushi YAMAMOTO, Yoshihiro MORIYA, Akiyoshi SABU, Daisuke ASAHINA, Yoshitaka YAMAUCHI, Taichi NEMOTO, Yukiko NAKAJIMA, Daiki YAMASHITA, Masahide YAMADA, Keiji MAKABE
  • Patent number: 8263302
    Abstract: A carrier for electrophotographic developer, including a core material; and a layer comprising a binder resin, located overlying the core material, wherein the binder resin includes a segment including one or more polymerizable vinyl monomers as a structural unit; and another segment including a partial cleavage structure of polyhedral oligomeric silsesquioxane and/or another partial cleavage structure of polyhedral oligomeric silsesquioxane as a structural unit.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: September 11, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Moriya, Akihiro Kotsugai, Toyoshi Sawada, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita
  • Patent number: 8114560
    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: Grant
    Filed: May 9, 2008
    Date of Patent: February 14, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Akihiro Kotsugai, Akiyoshi Sabu, Hiroshi Yamashita, Hiroshi Yamada, Junichi Awamura, Tsuyoshi Sugimoto
  • Publication number: 20110281213
    Abstract: A toner containing a binder resin comprising a first binder resin A and a second binder resin B, a coloring agent, and a releasing agent, wherein the first binder resin A is formed by reacting a compound A1 having an active hydrogen group with a resin A2 having a portion reactive with the compound A1 in an organic solvent and the resin A2 is formed by reacting a non-crystalline polyester resin “a” having a polyhydroxy carboxylic acid skeleton in the main chain with a compound having the portion reactive with the compound A1 having an active hydrogen group.
    Type: Application
    Filed: May 9, 2011
    Publication date: November 17, 2011
    Inventors: Shingo SAKASHITA, Shinya Nakayama, Ryota Inoue, Yoshihiro Moriya, Akiyoshi Sabu, Yukiko Nakajima, Daiki Yamashita
  • Patent number: 8017292
    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: Grant
    Filed: April 30, 2008
    Date of Patent: September 13, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Akiyoshi Sabu, Akihiro Kotsugai, Shinya Nakayama, Hiroshi Yamashita, Tsuyoshi Sugimoto, Hiroshi Yamada, Junichi Awamura
  • Publication number: 20110151370
    Abstract: The present invention provides a toner including: a colorant, and a binder resin, wherein the toner is fixed on a recording medium using a fixing liquid containing a softening agent for softening the toner, and wherein a weight average molecular weight of a THF soluble fraction of the toner in a molecular weight distribution measured by gel permeation chromatography (GPC) is 3,000 to 8,300; and a glass transition temperature of the toner measured by differential scanning calorimetry (DSC) is 50° C. to 70° C.
    Type: Application
    Filed: December 20, 2010
    Publication date: June 23, 2011
    Inventors: Yasutada SHITARA, Yohichiroh Watanabe, Yasuo Katano, Shinya Nakayama, Ryota Inoue, Yoshihiro Moriya, Akiyoshi Sabu, Shingo Sakashita, Yukiko Nakajima
  • Patent number: 7960083
    Abstract: An image forming apparatus including a charging unit, an exposing unit, a developing unit, a transferring unit, and a fixing unit. A toner containing a colorant and a binder resin which contains a polyester resin (A) and a polyester resin (B) having a softening point 10° C. or more higher than that of the polyester resin (A); the polyester resin (A) is a (meth)acrylic acid-modified rosin derived resin having a polyester unit obtained by polycondensation of an alcohol component, which contains 65 mol % or more of 1,2-propanediol in a dihydric alcohol component, and a carboxylic acid component containing a (meth)acrylic acid-modified rosin; the polyester resin (B) is a purified rosin derived resin having a polyester unit obtained by polycondenstation of an alcohol component, which contains a total of 70 mol % or more of 1,2-propanediol and 1,3-propanediol in a dihydric alcohol component, and a carboxylic acid component containing purified rosin.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: June 14, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Akihiro Kotsugai, Akiyoshi Sabu
  • Publication number: 20110129775
    Abstract: The present invention provides an image forming toner including at least a linear polyester resin (b1) as a binder resin, wherein the linear polyester resin (b1) is obtained by reacting a polyester diol (b11) having a polyhydroxycarboxylic acid skeleton, with a polyester diol (b12) other than the polyester diol (b11) in the presence of a chain extending agent.
    Type: Application
    Filed: June 17, 2009
    Publication date: June 2, 2011
    Inventors: Toyoshi Sawada, Akihiro Kotsugai, Akiyoshi Sabu
  • Publication number: 20110124838
    Abstract: The present invention provides a method for producing a toner, which includes 1) saccharifying paper by at least one of a chemical degradation method and a biochemical degradation method to obtain a sugar-containing solution, 2) subjecting the sugar-containing solution obtained through 1) to lactic acid fermentation to obtain a lactic acid, 3) polymerizing the lactic acid obtained through 2) to obtain a polylactic acid, and 4) producing a toner using the polylactic acid obtained through 3).
    Type: Application
    Filed: November 18, 2010
    Publication date: May 26, 2011
    Inventors: Akihiro Kotsugai, Keiko Osaka, Yoshihiro Moriya, Shingo Sakashita, Yukiko Nakajima, Yoshitaka Yamauchi, Ryota Inoue, Akiyoshi Sabu, Daiki Yamashita
  • Publication number: 20110104608
    Abstract: To provide a toner including: a resin particle (C) containing a first resin (a1), a second resin (a2), and a resin particle (B) to a surface of which the first resin (a1) and the second resin (a2) are attached, wherein the first resin (a1) and the second resin (a2) have mutually different glass transition temperatures, and wherein the resin particle (B) contains a third resin (b) having an amorphous polyhydroxycarboxylic acid skeleton.
    Type: Application
    Filed: August 3, 2010
    Publication date: May 5, 2011
    Inventors: Yukiko NAKAJIMA, Akihiro Kotsugai, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita, Keiko Osaka
  • Publication number: 20110065036
    Abstract: A toner including: a first binder resin; a colorant; a releasing agent; and a crystalline organic compound, wherein the first binder resin contains an amorphous polyester resin (a) having a polyhydroxycarboxylic acid skeleton derived from optically active monomers in a part of a main chain of the amorphous polyester resin, and the polyhydroxycarboxylic acid skeleton has an optical purity X, calculated on the monomer basis, of 80% or less, and the optical purity X is determined from the equation, Optical Purity X (%)=|X (L-form)?X (D-form)| wherein the crystalline organic compound is any one of a crystalline polyester resin (b) and a crystalline low molecular compound having a melting point of 60° C. to 100° C., and being selected from a group consisting of fatty acid having 16 to 24 carbon atoms, alcohol having 16 to 24 carbon atoms, a fatty acid ester compound, and aliphatic carboxylic acid amide.
    Type: Application
    Filed: September 9, 2010
    Publication date: March 17, 2011
    Inventors: Ryota Inoue, Akihiro Kotsugai, Yoshihiro Moriya, Akiyoshi Sabu, Shingo Sakashita, Keiko Osaka, Yukiko Nakajima, Yoshitaka Yamauchi, Daiki Yamashita
  • Publication number: 20100330489
    Abstract: An electrostatic image developing toner including a toner particle (C), wherein the toner particle (C) has a structure in which a resin particle (A) containing at least a first resin (a) or a coated film (P) containing the first resin (a) is attached to a surface of a resin-containing particle (B) containing a second resin (b), and wherein the resin (b) includes a polyhydroxycarboxylic acid skeleton, and the resin (a) is a polyester resin containing a polybasic acid and a polyhydric alcohol.
    Type: Application
    Filed: June 28, 2010
    Publication date: December 30, 2010
    Inventors: Ryota INOUE, Akihiro Kotsugai, Akiyoshi Sabu, Shingo Sakashita, Yukiko Nakajima, Keiko Osaka
  • Publication number: 20100216068
    Abstract: A toner including a colorant, a thermoplastic resin (a) comprising an amorphous polyester resin having a main chain having a polyhydroxycarboxylic acid skeleton, and a thermoplastic resin (b) is provided. The toner is manufactured by a method including mixing the colorant with the thermoplastic resin (a) to prepare a preliminary mixture, and mixing the preliminary mixture with the thermoplastic resin (b).
    Type: Application
    Filed: February 26, 2010
    Publication date: August 26, 2010
    Inventors: Akihiro KOTSUGAI, Toyoshi Sawada, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita, Keiko Osaka, Yukiko Nakajima
  • Publication number: 20100183967
    Abstract: A toner including a binder resin comprising a resin (a) comprising a polyhydroxycarboxylic acid skeleton formed from an optically-active monomer. The polyhydroxycarboxylic acid skeleton has a weight average molecular weight of from 7,000 to 60,000. The binder resin comprises the polyhydroxycarboxylic acid skeleton in an amount of from 10 to 90% by weight. The optical purity X (%) of the polyhydroxycarboxylic acid skeleton represented by the following formula is 80% or less: X(%)=|X(L-isomer)?X(D-isomer)| wherein X(L-isomer) and X(D-isomer) represent molar ratio (%) of L-isomer and D-isomer of the optically-active monomer, respectively.
    Type: Application
    Filed: December 30, 2009
    Publication date: July 22, 2010
    Inventors: Akiyoshi Sabu, Akihiro Kotsugai, Ryota Inoue, Keiko Osaka, Shingo Sakashita, Yukiko Nakajima, Satoshi Mochizuki
  • Publication number: 20100104965
    Abstract: The toner includes a binder resin; a release agent; a colorant; and a dispersing resin configured to disperse the release agent. The dispersing resin includes a polyhydroxycarboxylic acid unit obtained from an optically active monomer. The polyhydroxycarboxylic acid unit has an optical purity of not greater than 80%, wherein the optical purity is defined as the absolute value of difference between the mole percentage of a L-monomer in the optically active monomer and the mole percentage of a D-monomer in the optically active monomer.
    Type: Application
    Filed: October 8, 2009
    Publication date: April 29, 2010
    Inventors: Ryota INOUE, Akihiro Kotsugai, Toyoshi Sawada, Akiyoshi Sabu
  • Publication number: 20100061759
    Abstract: A carrier for electrophotographic developer, including a core material; and a layer comprising a binder resin, located overlying the core material, wherein the binder resin includes a segment including one or more polymerizable vinyl monomers as a structural unit; and another segment including a partial cleavage structure of polyhedral oligomeric silsesquioxane and/or another partial cleavage structure of polyhedral oligomeric silsesquloxane as a structural unit.
    Type: Application
    Filed: September 8, 2009
    Publication date: March 11, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yoshihiro MORIYA, Akihiro Kotsugai, Toyoshi Sawada, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita
  • Publication number: 20090103950
    Abstract: An image forming apparatus including: a latent electrostatic image bearing member, a charging unit, an exposing unit, a developing unit, a transfer unit, and a fixing unit, wherein the toner contains at least a binder resin and a colorant, the binder resin contains a polyester resin obtained by polycondensation of an alcohol component with a carboxylic acid component containing a rosin compound, the amount of the rosin compound contained in the carboxylic acid component is 5% by mass or more based on the total mass of the alcohol component and carboxylic acid component, and the amount of an abietic acid contained in the toner is 1% by mass or less.
    Type: Application
    Filed: October 17, 2008
    Publication date: April 23, 2009
    Inventors: Shinya Nakayama, Akihiro Kotsugai, Akiyoshi Sabu
  • Publication number: 20090003885
    Abstract: A toner including a colorant and a binder resin is provided. The binder resin includes a first resin comprising a block X comprising a resin comprising a racemic mixture of optically active monomers of a D-form compound and an L-form compound, and a block Y comprising another resin. The weight ratio of the D-form compound to the L-form compound is from 48/52 to 52/48, and the weight ratio of the block Y to the block X is from 1/3 to 3/1. The toner is obtained by dispersing or emulsifying a toner constituent liquid, in which the colorant and the binder resin are dissolved or dispersed in an organic solvent, in an aqueous medium.
    Type: Application
    Filed: June 27, 2008
    Publication date: January 1, 2009
    Inventors: Akiyoshi Sabu, Akihiro Kotsugai, Shinya Nakayama, Hiroshi Yamashita, Yoshihiro Moriya
  • Publication number: 20080318143
    Abstract: An image forming apparatus including a charging unit, an exposing unit, a developing unit, a transferring unit, and a fixing unit. A toner containing a colorant and a binder resin which contains a polyester resin (A) and a polyester resin (B) having a softening point 10° C. or more higher than that of the polyester resin (A); the polyester resin (A) is a (meth)acrylic acid-modified rosin derived resin having a polyester unit obtained by polycondensation of an alcohol component, which contains 65 mol % or more of 1,2-propanediol in a dihydric alcohol component, and a carboxylic acid component containing a (meth)acrylic acid-modified rosin; the polyester resin (B) is a purified rosin derived resin having a polyester unit obtained by polycondenstation of an alcohol component, which contains a total of 70 mol % or more of 1,2-propanediol and 1,3-propanediol in a dihydric alcohol component, and a carboxylic acid component containing purified rosin.
    Type: Application
    Filed: June 19, 2008
    Publication date: December 25, 2008
    Inventors: Shinya Nakayama, Akihiro Kotsugai, Akiyoshi Sabu