Patents by Inventor Ryoichi Fujita

Ryoichi Fujita 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: 8524434
    Abstract: A toner having a toner particle including a core particle obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant, a release agent, a polar resin, and a crystalline polyester in an aqueous medium and an outer shell formed by fixing resin fine particles to the surface of the core particle, wherein the resin constituting the resin fine particles is an amorphous resin and the acid value of the resin fine particles is 4.0 to 50.0 mgKOH/g.
    Type: Grant
    Filed: June 9, 2011
    Date of Patent: September 3, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsuneyoshi Tominaga, Ryoichi Fujita, Tsutomu Shimano
  • Patent number: 8460845
    Abstract: Provided is a cyan toner which, while being a capsule-type toner having excellent low-temperature fixability, has excellent offset resistance and charging performance and can obtain high-quality images. A cyan toner having at least a resin (a) having a polyester as a main component, a colorant, and a wax, in which glass transition temperatures (° C.) Tg(0.5) and Tg(4.0) obtained at a rate of temperature increase of 0.5° C./min or 4.0° C./min satisfy 40.0?Tg(0.5)?60.0 and 2.0?Tg(4.0)?Tg(0.5)?10.0, and wherein, when the concentration of the cyan toner in an ethyl acetate dispersion is Cc1 (mg/ml), and the light absorbance at a wavelength of 712 nm of the dispersion is A(ethyl acetate)712, A(ethyl acetate)712/Cc1<0.15 is satisfied, and wherein, when the concentration of the cyan toner in a chloroform solution is Cc2 (mg/ml), and the light absorbance at a wavelength of 712 nm of the solution is A(chloroform)712, 2.00<A(chloroform)712/Cc2<8.15 is satisfied.
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: June 11, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kaya, Ayako Sekikawa, Ryoichi Fujita, Shigeto Tamura, Makoto Kambayashi
  • Publication number: 20110305984
    Abstract: A toner having a toner particle including a core particle obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant, a release agent, a polar resin, and a crystalline polyester in an aqueous medium and an outer shell formed by fixing resin fine particles to the surface of the core particle, wherein the resin constituting the resin fine particles is an amorphous resin and the acid value of the resin fine particles is 4.0 to 50.0 mgKOH/g.
    Type: Application
    Filed: June 9, 2011
    Publication date: December 15, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tsuneyoshi Tominaga, Ryoichi Fujita, Tsutomu Shimano
  • Patent number: 7943281
    Abstract: In a black toner having at least a binder resin and an iron-titanium composite oxide as a colorant; the iron-titanium composite oxide is contained in a specific amount; the black toner has a specific weight average particle diameter and a specific saturation magnetization; the black toner has, in X-ray diffraction thereof, a maximum peak at 2?=from 32.5 to 33.1 degrees, having a half width of 0.25 degree or less. The black toner has, in a proportion of less than 30% by number, an iron-titanium composite oxide having, in a sectional photograph of the toner, a maximum frequency of linearity within the range where the linearity is smaller than 2.4 and having a linearity of 3.0 or more, in regard to the number frequency distribution of the linearity of the iron-titanium composite oxide.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: May 17, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kaya, Yasukazu Ayaki, Shigeto Tamura, Yayoi Tazawa, Ryoichi Fujita, Yuichi Yajima
  • Publication number: 20100273102
    Abstract: The color toner has capsule toner particles each having a surface layer (B) mainly formed of a resin (b) on the surface of a toner base particle (A), the toner base particle (A) containing at least a binder resin (a), a colorant, and a wax, in which (1) a temperature Tp at which a curve 1 obtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G? of the color toner by the unit of the loss modulus on an axis of ordinate shows a maximum is present, and Tp satisfies the relationship of 40° C.?Tp?60° C., (2) a temperature Ts at which a curve 2 obtained by differentiating the curve 1 with respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10 (° C.) to Tp+40 (° C.), and (3) a ratio G?(Ts)/G?(Ts+5) in the curve 1 is larger than 3.0.
    Type: Application
    Filed: July 8, 2010
    Publication date: October 28, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shigeto Tamura, Takaaki Kaya, Ryoichi Fujita, Makoto Kambayashi
  • Patent number: 7794908
    Abstract: Provided is magnetic toner including capsule type toner particles each having a surface layer (B) on a surface of a toner base particle (A) containing at least a binder resin (a) mainly formed of a polyester, a magnetic substance, and a wax, in which, the surface layer (B) includes a resin (b), and the resin (b) includes a resin selected from the group consisting of a polyester resin (b1), a vinyl resin (b2), and a urethane resin (b3); a glass transition temperature Tg(a) of the binder resin (a) and a glass transition temperature Tg(b) of the resin (b) satisfy a relationship of Tg(a)<Tg(b); a magnetization (?t) in an external magnetic field of 79.6 kA/m of the magnetic toner is 12 Am2/kg or more and 30 Am2/kg or less; and an average circularity of the toner is 0.960 or more and 1.000 or less.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: September 14, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Makoto Kambayashi, Takeshi Ikeda
  • Patent number: 7794909
    Abstract: An object of the present invention is to provide a spherical toner that has a sharp particle size distribution and a small particle diameter. This is a capsule-type toner that exhibits an excellent low-temperature fixability, while at the same time having a high offset resistance and excellent charging properties and having the ability to provide a high-quality image in which the characters, lines, and dots are precisely defined. The object is achieved by a toner comprising a toner particle that comprises at least (a) resin having polyester as the main component, colorant, wax, and (b) urethane resin, wherein the hydroxyl value per specific surface area of the toner particle is fall into the specific range, and wherein a Tg(0.5) and a Tg(4.0)-Tg(0.5) of the toner fall into specific range.
    Type: Grant
    Filed: July 6, 2009
    Date of Patent: September 14, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Ayako Sekikawa, Makoto Kambayashi
  • Patent number: 7776501
    Abstract: The color toner has capsule type toner particles each having a surface layer (B) mainly formed of a resin (b) on the surface of a toner base particle (A) containing at least a binder resin (a), a colorant, and a wax, in which (1) a temperature Tp at which a curve 1 obtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G? of the color toner by the unit of the loss modulus on an axis of ordinate shows a maximum is present, and Tp satisfies the relationship of 40° C.?Tp?60° C., (2) a temperature Ts at which a curve 2 obtained by differentiating the curve 1 with respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10(° C.) to Tp+40(° C.), and (3) a ratio G?(Ts)/G?(Ts+5) in the curve 1 is larger than 3.0.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: August 17, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeto Tamura, Takaaki Kaya, Ryoichi Fujita, Makoto Kambayashi
  • Publication number: 20100062355
    Abstract: Provided is a cyan toner which, while being a capsule-type toner having excellent low-temperature fixability, has excellent offset resistance and charging performance and can obtain high-quality images. A cyan toner having at least a resin (a) having a polyester as a main component, a colorant, and a wax, in which glass transition temperatures (° C.) Tg(0.5) and Tg(4.0) obtained at a rate of temperature increase of 0.5° C./min or 4.0° C./min satisfy 40.0?Tg(0.5)?60.0 and 2.0?Tg(4.0)?Tg(0.5)?10.0, and wherein, when the concentration of the cyan toner in an ethyl acetate dispersion is Cc1 (mg/ml), and the light absorbance at a wavelength of 712 nm of the dispersion is A(ethyl acetate)712, A(ethyl acetate)712/Cc1<0.15 is satisfied, and wherein, when the concentration of the cyan toner in a chloroform solution is Cc2 (mg/ml), and the light absorbance at a wavelength of 712 nm of the solution is A(chloroform)712, 2.00<A(chloroform)712/Cc2<8.15 is satisfied.
    Type: Application
    Filed: November 12, 2009
    Publication date: March 11, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takaaki Kaya, Ayako Sekikawa, Ryoichi Fujita, Shigeto Tamura, Makoto Kambayashi
  • Publication number: 20090263738
    Abstract: An object of the present invention is to provide a spherical toner that has a sharp particle size distribution and a small particle diameter. This is a capsule-type toner that exhibits an excellent low-temperature fixability, while at the same time having a high offset resistance and excellent charging properties and having the ability to provide a high-quality image in which the characters, lines, and dots are precisely defined. The object is achieved by a toner comprising a toner particle that comprises at least (a) resin having polyester as the main component, colorant, wax, and (b) urethane resin, wherein the hydroxyl value per specific surface area of the toner particle is fall into the specific range, and wherein a Tg(0.5) and a Tg(4.0)-Tg(0.5) of the toner fall into specific range.
    Type: Application
    Filed: July 6, 2009
    Publication date: October 22, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Ayako Sekikawa, Makoto Kambayashi
  • Publication number: 20090170021
    Abstract: Provided is magnetic toner including capsule type toner particles each having a surface layer (B) on a surface of a toner base particle (A) containing at least a binder resin (a) mainly formed of a polyester, a magnetic substance, and a wax, in which, the surface layer (B) includes a resin (b), and the resin (b) includes a resin selected from the group consisting of a polyester resin (b1), a vinyl resin (b2), and a urethane resin (b3); a glass transition temperature Tg(a) of the binder resin (a) and a glass transition temperature Tg(b) of the resin (b) satisfy a relationship of Tg(a)<Tg(b); a magnetization (?t) in an external magnetic field of 79.6 kA/m of the magnetic toner is 12 Am2/kg or more and 30 Am2/kg or less; and an average circularity of the toner is 0.960 or more and 1.000 or less.
    Type: Application
    Filed: March 2, 2009
    Publication date: July 2, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Makoto Kambayashi, Takeshi Ikeda
  • Publication number: 20090035685
    Abstract: The color toner has capsule type toner particles each having a surface layer (B) mainly formed of a resin (b) on the surface of a toner base particle (A) containing at least a binder resin (a), a colorant, and a wax, in which (1) a temperature Tp at which a curve 1 obtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G? of the color toner by the unit of the loss modulus on an axis of ordinate shows a maximum is present, and Tp satisfies the relationship of 40° C.?Tp?60° C., (2) a temperature Ts at which a curve 2 obtained by differentiating the curve 1 with respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10(° C.) to Tp+40(° C.), and (3) a ratio G?(Ts)/G?(Ts+5) in the curve 1 is larger than 3.0.
    Type: Application
    Filed: October 3, 2008
    Publication date: February 5, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shigeto Tamura, Takaaki Kaya, Ryoichi Fujita, Makoto Kambayashi
  • Publication number: 20090011353
    Abstract: In a black toner having at least a binder resin and an iron-titanium composite oxide as a colorant; the iron-titanium composite oxide is contained in a specific amount; the black toner has a specific weight average particle diameter and a specific saturation magnetization; the black toner has, in X-ray diffraction thereof, a maximum peak at 2?=from 32.5 to 33.1 degrees, having a half width of 0.25 degree or less. The black toner has, in a proportion of less than 30% by number, an iron-titanium composite oxide having, in a sectional photograph of the toner, a maximum frequency of linearity within the range where the linearity is smaller than 2.4 and having a linearity of 3.0 or more, in regard to the number frequency distribution of the linearity of the iron-titanium composite oxide.
    Type: Application
    Filed: April 14, 2006
    Publication date: January 8, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takaaki Kaya, Yasukazu Ayaki, Shigeto Tamura, Yayoi Tazawa, Ryoichi Fujita, Yuichi Yajima
  • Patent number: 7244539
    Abstract: A magnetic carrier includes a magnetic material-dispersed resin core containing at least a magnetic material and a binder resin. The surface of the magnetic material-dispersed resin core is coated with a coating material containing at least a fluorine resin and 1 to 40 parts by weight of fine particles based on 100 parts by weight of the fluorine resin. The coating material is in an amount of 0.3 to 4.0 parts by weight based on 100 parts by weight of the magnetic material-dispersed resin core. The magnetic carrier has a contact angle of 95 to 125°. A two-component developer is also provided which makes use of the magnetic carrier.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: July 17, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshinobu Baba, Ryoichi Fujita, Takaaki Kaya, Kazuo Terauchi
  • Patent number: 7144668
    Abstract: The present invention provides a toner: comprising a binder resin comprising a polyester unit, a colorant, a releasing agent, and inorganic fine particles; has a weight average particle diameter of 3.0–6.5 ?m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 ?m or more of 0.920–0.945; has a BET specific surface area of 2.1–3.5 m2/g; and has a permeability of light of a wavelength of 600 nm in a liquid having dispersed the toner in a 45 vol % methanol aq. of 30–80%. The present invention also provides a two-component developer: comprising the toner and a magnetic carrier comprising magnetic core particles coated by a coating layer; and has a number average particle diameter of 15–80 ?m. Using the toner and the two-component developer enables a high-quality image to be formed at a high speed even in an oilless fixing system.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: December 5, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshinobu Baba, Yuko Sato, Ryoichi Fujita, Takaaki Kotaki, Nobuyoshi Sugahara, Kazuo Terauchi, Takayuki Itakura
  • Patent number: 6953648
    Abstract: A process for producing toner particles, in which toner particles are produced by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer in an aqueous medium in a vessel, is provided. In this process, a resin composition containing a THF-insoluble resin component, which is a resin component generated in the process for producing toner particles, is kneaded. Then, the kneaded material and the polymerizable monomer are mixed together, and the resulting polymerizable monomer is polymerized to produce toner particles. For the resin composition, toner particles different from those having desired property, deposits on the vessel where the polymerization reaction occurred, or the like is used.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: October 11, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Tsujino, Hitosi Kanda, Ryoichi Fujita, Yoshinori Tsuji
  • Publication number: 20040253529
    Abstract: A magnetic carrier includes a magnetic material-dispersed resin core containing at least a magnetic material and a binder resin. The surface of the magnetic material-dispersed resin core is coated with a coating material containing at least a fluorine resin and 1 to 40 parts by weight of fine particles based on 100 parts by weight of the fluorine resin. The coating material is in an amount of 0.3 to 4.0 parts by weight based on 100 parts by weight of the magnetic material-dispersed resin core. The magnetic carrier has a contact angle of 95 to 125°. A two-component developer is also provided which makes use of the magnetic carrier.
    Type: Application
    Filed: April 29, 2004
    Publication date: December 16, 2004
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshinobu Baba, Ryoichi Fujita, Takaaki Kaya, Kazuo Terauchi
  • Publication number: 20040175643
    Abstract: The present invention provides a toner: comprising a binder resin comprising a polyester unit, a colorant, a releasing agent, and inorganic fine particles; has a weight average particle diameter of 3.0-6.5 &mgr;m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 &mgr;m or more of 0.920-0.945; has a BET specific surface area of 2.1-3.5 m2/g; and has a permeability of light of a wavelength of 600 nm in a liquid having dispersed the toner in a 45 vol % methanol aq. of 30-80%. The present invention also provides a two-component developer: comprising the toner and a magnetic carrier comprising magnetic core particles coated by a coating layer; and has a number average particle diameter of 15-80 &mgr;m. Using the toner and the two-component developer enables a high-quality image to be formed at a high speed even in an oilless fixing system.
    Type: Application
    Filed: March 5, 2004
    Publication date: September 9, 2004
    Inventors: Yoshinobu Baba, Yuko Sato, Ryoichi Fujita, Takaaki Kotaki, Nobuyoshi Sugahara, Kazuo Terauchi, Takayuki Itakura
  • Publication number: 20030232269
    Abstract: A process for producing toner particles, in which toner particles are produced by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer in an aqueous medium in a vessel, is provided. In this process, a resin composition containing a THF-insoluble resin component, which is a resin component generated in the process for producing toner particles, is kneaded. Then, the kneaded material and the polymerizable monomer are mixed together, and the resulting polymerizable monomer is polymerized to produce toner particles. For the resin composition, toner particles different from those having desired property, deposits on the vessel where the polymerization reaction occurred, or the like is used.
    Type: Application
    Filed: April 24, 2003
    Publication date: December 18, 2003
    Inventors: Takeshi Tsujino, Hitosi Kanda, Ryoichi Fujita, Yoshinori Tsuji
  • Patent number: 6346356
    Abstract: A toner is comprised of toner particles containing at least a binder resin, a colorant, a wax component and an oxycarboxylic acid. The toner satisfies the following conditions: 1.05≦A/B≦3.00, and 0.15≦B≦3.50 wherein A (mg) is a weight of oxycarboxylic acid extracted with methanol from 1 g of the toner, and B (mg) is a weight of oxycarboxylic acid extracted with an aqueous 0.1 mol/liter sodium hydroxide solution from 1 g of the toner.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: February 12, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Manabu Ohno, Toshiyuki Ugai, Ryoichi Fujita, Shinya Yachi, Yasushi Katsuta, Kenichi Nakayama