Patents by Inventor Katsuhisa Yamazaki

Katsuhisa Yamazaki 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: 20160041484
    Abstract: Provided is a toner having good endurance stability and good low-temperature fixability in high-speed printing, and having good resistance to the adhesion of printed paper. The toner is a magnetic toner having, on the surface of toner particle containing a binder resin and an ester compound as a releasing agent, inorganic fine particle “a” and organic-inorganic composite fine particle having a volumetric specific heat of from 2,900 kJ/(m3·° C.) to 4,200 kJ/(m3·° C.), in which a coverage A of the surface of the toner particle with the inorganic fine particle “a” is 45.0% or more and 70.0% or less.
    Type: Application
    Filed: July 29, 2015
    Publication date: February 11, 2016
    Inventors: Shohei Tsuda, Yojiro Hotta, Koji Nishikawa, Masami Fujimoto, Katsuhisa Yamazaki
  • Publication number: 20160041483
    Abstract: The present invention provides a magnetic toner that is excellent in low temperature fixability and that is also excellent in developability, suppression of fogging and transfer efficiency even in a long period of use. The magnetic toner of the present invention is a magnetic toner including a magnetic toner particle containing a binder resin and a magnetic member, and an inorganic fine particle “a” and an organic-inorganic composite fine particle, wherein the magnetic toner has (i) a true specific gravity of 1.40 g/cm3 or more and 1.70 g/cm3 or less, and (ii) a saturation magnetization at a magnetic field of 796 kA/m of 10 Am2/kg or more and 20 Am2/kg or less, and the inorganic fine particle “a” is a metal oxide having a volume resistivity of 1.0×103 ?·cm or more and 1.0×108 ?·cm or less.
    Type: Application
    Filed: July 23, 2015
    Publication date: February 11, 2016
    Inventors: Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Hiroki Akiyama, Shohei Tsuda, Daisuke Yoshiba, Katsuhisa Yamazaki
  • Patent number: 9250548
    Abstract: The toner comprises: toner particles each containing a binder resin and a releasing agent; and an organic-inorganic composite fine particle, wherein: the organic-inorganic composite fine particle comprises: a vinyl resin particle containing a vinyl resin, the vinyl resin containing THF-insoluble matter in an amount of 95% by mass or more; and inorganic fine particles which are exposed at surfaces of the respective organic-inorganic composite fine particles, the organic-inorganic composite fine particle 1) has a plurality of convexes derived from the inorganic fine particles on the surfaces thereof, 2) has a number average particle size of 70-500 nm, and 3) has a shape factor SF-2 as measured at a magnification of 200,000 times of 103-120, and an absolute value of difference between an SP value of the releasing agent and an SP value of the vinyl resin is 0.50 (cal/cm3)1/2 or less.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: February 2, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Koji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
  • Patent number: 9201323
    Abstract: A toner excellent in end-portion hot offset properties is provided. A toner including toner particles and an external additive, wherein the toner particles contain a binder resin, and organic-inorganic composite fine particles dispersed in the binder resin, and the organic-inorganic composite fine particles (1) have a number-average particle diameter of 70 nm or more and 500 nm or less, (2) have a structure in which inorganic fine particles are embedded in a resin particle, convexes derived from the inorganic fine particles being present on surfaces of the organic-inorganic composite fine particles, (3) have a shape factor SF-2 of 103 or more and 120 or less, and (4) contain a resin component in which a proportion of THF-insoluble matter based on a mass of the resin component is 95% by mass or more.
    Type: Grant
    Filed: July 25, 2014
    Date of Patent: December 1, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji Nishikawa, Katsuhisa Yamazaki, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Patent number: 9128400
    Abstract: To provide a toner that can keep its melt-sticking to sleeve from occurring and, even in double-sided printing, can keep high-temperature offset from occurring and obtain high-quality images on both the surface and the back. The toner comprises toner particles each of which contains a binder resin containing a resin formed by the reaction of i) a resin (A) having a softening point TA (° C.) of 70° C. to 105° C. and having a peak top of endothermic peaks at 55° C. to 120° C. with ii) a resin (B) having a softening point TB (° C.) of 120° C. to 160° C. and having a peak top of endothermic peaks at 55° C. to 120° C., and, in its viscoelasticity characteristics, has a storage elastic modulus at temperature 180° C. (G?180) of 3.0×103 Pa to 3.0×104 Pa, where the loss tangent tan ? has at least one peak having a peak top within the range of 50° C. to 70° C. and, when peak top temperature of the peak is represented by T(° C.), the loss tangent at T+10(° C.) [tan ?(T+10)] is 1.0 to 1.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: September 8, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Toru Takahashi, Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Daisuke Tsujimoto, Masami Fujimoto
  • Patent number: 9097998
    Abstract: A toner is provided which is superior in the long-term storage stability and has high low-temperature fixing properties. In a DSC curve as measured with a differential scanning calorimeter, the toner has a glass transition temperature of not less than 50° C. and not more than 60° C.; and the toner has, in regard to a resin composition contained therein, a difference of not less than 0.060 W/g in heat flow between a point on the curve at a temperature of 40° C. and a baseline in the range exceeding the glass transition temperature; and in viscoelastic characteristics measured at a frequency of 6.28 rad/sec, the toner has a storage elastic modulus (G?40) at a temperature of 40° C. of not less than 7.0×108 Pa and not more than 2.0×109 Pa, and a storage elastic modulus (G?70) at a temperature of 70° C. of not less than 1.0×105 Pa and not more than 1.0×107 Pa.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: August 4, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Publication number: 20150125790
    Abstract: A magnetic toner having a toner particle containing a binder resin and a magnetic member, a first inorganic fine particle and an organic-inorganic composite particle on the surface of the toner particle, wherein the organic-inorganic composite particle i) has a structure in which a second inorganic fine particle is embedded in a resin particle, and ii) is contained in an amount of 0.5 mass % or more and 3.0 mass % or less based on the mass of the toner; the first inorganic fine particle contains an inorganic oxide fine particle selected from the group consisting of a silica fine particle, a titanium oxide fine particle and an alumina fine particle; has a number average particle diameter (D1) of 5 nm or more and 25 nm or less, and contains the silica fine particle in an amount of 85 mass % or more based on the inorganic oxide fine particle.
    Type: Application
    Filed: January 13, 2015
    Publication date: May 7, 2015
    Inventors: Yojiro Hotta, Koji Nishikawa, Shohei Tsuda, Motohide Shiozawa, Takeshi Naka, Kazuo Terauchi, Katsuhisa Yamazaki, Takayuki Itakura
  • Publication number: 20150037726
    Abstract: The toner comprises: toner particles each containing a binder resin and a releasing agent; and an organic-inorganic composite fine particle, wherein: the organic-inorganic composite fine particle comprises: a vinyl resin particle containing a vinyl resin, the vinyl resin containing THF-insoluble matter in an amount of 95% by mass or more; and inorganic fine particles which are exposed at surfaces of the respective organic-inorganic composite fine particles, the organic-inorganic composite fine particle 1) has a plurality of convexes derived from the inorganic fine particles on the surfaces thereof, 2) has a number average particle size of 70-500 nm, and 3) has a shape factor SF-2 as measured at a magnification of 200,000 times of 103-120, and an absolute value of difference between an SP value of the releasing agent and an SP value of the vinyl resin is 0.50 (cal/cm3)1/2 or less.
    Type: Application
    Filed: July 24, 2014
    Publication date: February 5, 2015
    Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Kouji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
  • Publication number: 20150037729
    Abstract: The toner includes a resin component containing a crystalline polyester resin and a polyester-type resin that has a long-chain monomer bonded by condensation at a terminal, the toner having, in a total heat flow measured by a temperature-modulated differential scanning calorimeter, an endothermic peak resulting from the crystalline polyester resin in a specific temperature range, and the percentage of the endothermic quantity of the endothermic peak in a reversing heat flow with respect to the endothermic quantity of the endothermic peak in the total heat flow being at least 20.0%.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 5, 2015
    Inventors: Daisuke Yoshiba, Katsuhisa Yamazaki, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20150037721
    Abstract: Provided is a toner that has excellent low-temperature fixability and is capable of obtaining an image having a stable image density, in which the occurrence of image defects is suppressed. The toner includes toner base particles, each of which contains a binder resin and a magnetic material, and organic-inorganic composite fine particles on each of the toner base particles. Each of the organic-inorganic composite fine particles comprises a vinyl resin particle, and inorganic fine particles which are embedded in the vinyl resin particle, and at least a part of which are exposed. The volumetric specific heat of the organic-inorganic composite fine particles and the volumetric specific heat of the toner base particles satisfy a predetermined provision.
    Type: Application
    Filed: July 30, 2014
    Publication date: February 5, 2015
    Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Kouji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
  • Publication number: 20150037722
    Abstract: The present invention provides a toner that exhibits an excellent low-temperature fixability and an excellent ejected paper adhesiveness during high-speed printing, without affecting the long-term storage stability, in which the toner has a toner particle that contains a resin component, wherein the toner has, in a DSC curve measured with a differential scanning calorimeter, a glass transition temperature of at least 50° C. and not more than 65° C. and a cold crystallization peak during cooling of at least 40° C. and not more than 70° C., and has an endothermic peak in a DSC curve measured with a differential scanning calorimeter for the resin component of at least 70° C. and not more than 95° C.
    Type: Application
    Filed: July 28, 2014
    Publication date: February 5, 2015
    Inventors: Katsuhisa Yamazaki, Daisuke Yoshiba, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20150037723
    Abstract: A toner excellent in end-portion hot offset properties is provided. A toner including toner particles and an external additive, wherein the toner particles contain a binder resin, and organic-inorganic composite fine particles dispersed in the binder resin, and the organic-inorganic composite fine particles (1) have a number-average particle diameter of 70 nm or more and 500 nm or less, (2) have a structure in which inorganic fine particles are embedded in a resin particle, convexes derived from the inorganic fine particles being present on surfaces of the organic-inorganic composite fine particles, (3) have a shape factor SF-2 of 103 or more and 120 or less, and (4) contain a resin component in which a proportion of THF-insoluble matter based on a mass of the resin component is 95% by mass or more.
    Type: Application
    Filed: July 25, 2014
    Publication date: February 5, 2015
    Inventors: Koji Nishikawa, Katsuhisa Yamazaki, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20150037719
    Abstract: A toner is provided including large particle-diameter external additives with sweep to the concaves of a toner particle suppressed, so that the large particle-diameter external additives function as spacer particles for a long period. The toner includes toner particles which contain a binder resin and magnetic material, and organic-inorganic composite fine particles having a structure including inorganic fine particles embedded in a vinyl resin particle. The presence state of the magnetic material on the toner particle surface satisfies specific conditions and the presence state of the organic-inorganic composite fine particles on the toner surface satisfies specific conditions.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 5, 2015
    Inventors: Takeshi Naka, Kazuo Terauchi, Motohide Shiozawa, Yojiro Hotta, Shohei Tsuda, Katsuhisa Yamazaki, Koji Nishikawa, Takayuki Itakura
  • Publication number: 20150037720
    Abstract: Provided is magnetic toner capable of favorably maintain fluidity of the magnetic toner in a developing unit even after a large number of image formation. The magnetic toner to which an external additive that has 1) a number average particle diameter of 70 or more and 200 or less, 2) a shape factor SF-1 of 100 or more and 250 or less, and 3) a shape factor SF-2 of 105 or more and 250 or less, is added, and a covering rate by silica on the surfaces of toner particles is 40.0% or more and 70.0% or less, and the magnetic toner has specific fluidity.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 5, 2015
    Inventors: Shohei Tsuda, Yojiro Hotta, Kouji Nishikawa, Shotaro Nomura, Katsuhisa Yamazaki, Masami Fujimoto, Takayuki Itakura
  • Publication number: 20130309603
    Abstract: A toner having toner particles, each of which contains a binder resin and a colorant, wherein in viscoelastic properties of the toner as measured with a rotating flat plate rheometer at a frequency of 6.28 rad/sec: a storage elastic modulus at the temperature of 60° C. (G?60) is in a range from 1.0×107 to 1.0×109 (Pa), and a maximal value (G?p) exists for the storage elastic modulus in a temperature range from 110° C. to 140° C., with this G?p being in a range from 5.0×104 to 5.0×106 (Pa).
    Type: Application
    Filed: February 1, 2012
    Publication date: November 21, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Toru Takahashi, Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Tsujimoto, Yosuke Iwasaki, Masami Fujimoto
  • Publication number: 20130302730
    Abstract: To provide a toner that can keep its melt-sticking to sleeve from occurring and, even in double-sided printing, can keep high-temperature offset from occurring and obtain high-quality images on both the surface and the back. The toner comprises toner particles each of which contains a binder resin containing a resin formed by the reaction of i) a resin (A) having a softening point TA (° C.) of 70° C. to 105° C. and having a peak top of endothermic peaks at 55° C. to 120° C. with ii) a resin (B) having a softening point TB (° C.) of 120° C. to 160° C. and having a peak top of endothermic peaks at 55° C. to 120° C., and, in its viscoelasticity characteristics, has a storage elastic modulus at temperature 180° C. (G?180) of 3.0×103 Pa to 3.0×104 Pa, where the loss tangent tan ? has at least one peak having a peak top within the range of 50° C. to 70° C. and, when peak top temperature of the peak is represented by T(° C.), the loss tangent at T+10(° C.) [tan ?(T+10)] is 1.0 to 1.
    Type: Application
    Filed: December 15, 2011
    Publication date: November 14, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Toru Takahashi, Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Daisuke Tsujimoto, Masami Fujimoto
  • Publication number: 20130252167
    Abstract: A toner comprising toner particles, each of which contains a binder resin and a colorant, wherein the binder resin includes a resin having an endothermic peak at a temperature of 55° C. to 120° C. in a DSC curve; the toner has a softening point Tm of 90° C. to 140° C.; in the viscoelastic characteristic of the toner measured at a frequency of 6.28 rad/sec, the storage elastic modulus at a temperature of 180° C. is 1.0×102 Pa to 1.0×104 Pa; in a chart with the temperature on the x-axis and tan ? on the y-axis, tan ? has a peak having a peak top in the range of 50° C. to 70° C.; tan ? (P) at the peak top temperature is 2.0 to 10.0; the ratio of the tan ? (P) at the peak top temperature to tan ? (Tm) at a temperature of Tm (tan ? (P)/tan ? (Tm)) is in the range of 2.5 to 8.0.
    Type: Application
    Filed: December 13, 2011
    Publication date: September 26, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shuhei Moribe, Katsuhisa Yamazaki, Daisuke Yoshiba, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Publication number: 20130244166
    Abstract: A toner is provided which is superior in the long-term storage stability and has high low-temperature fixing properties. In a DSC curve as measured with a differential scanning calorimeter, the toner has a glass transition temperature of not less than 50° C. and not more than 60° C.; and the toner has, in regard to a resin composition contained therein, a difference of not less than 0.060 W/g in heat flow between a point on the curve at a temperature of 40° C. and a baseline in the range exceeding the glass transition temperature; and in viscoelastic characteristics measured at a frequency of 6.28 rad/sec, the toner has a storage elastic modulus (G?40) at a temperature of 40° C. of not less than 7.0×108 Pa and not more than 2.0×109 Pa, and a storage elastic modulus (G?70) at a temperature of 70° C. of not less than 1.0×105 Pa and not more than 1.0×107 Pa.
    Type: Application
    Filed: December 22, 2011
    Publication date: September 19, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Patent number: 8512925
    Abstract: Provided is a magnetic toner capable of preventing electrostatic offset while attaining a high image quality by a high speed machine. The magnetic toner comprises magnetic toner particles, each of which contains a binder resin and a magnetic material, and a fine inorganic powder, in which the binder resin contains a polyester unit, and the magnetic toner has a dielectric loss factor at 40° C. and 100 kHz of 0.40 pF/m or more but 1.00 pF/m or less and a dielectric loss factor at 150° C. and 100 kHz of 0.50 pF/m or more but 4.00 pF/m or less.
    Type: Grant
    Filed: January 19, 2012
    Date of Patent: August 20, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shuhei Moribe, Katsuhisa Yamazaki, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Patent number: 8507170
    Abstract: An image-forming method includes forming an electrostatic image on an electrostatic image bearing member which has been charged; developing the electrostatic image to form a toner image; transferring the toner image on the electrostatic image bearing member with or without mediating an intermediate transferring member onto a transfer material; and fixing the toner image on the transfer material. The electrostatic image bearing member is a photosensitive member obtained by sequentially laminating a photoconductive layer and a surface layer formed of hydrogenated amorphous silicon carbide, and a sum of an atomic density of silicon atoms and an atomic density of carbon atoms in the surface layer of the photosensitive member is 6.60×1022 atoms/cm3 or more. The toner has a binder resin and magnetic iron oxide particles, and the magnetic iron oxide particles contain Fe(2+) at a content of 20.0 mass % or more and 25.0 mass % or less.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: August 13, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tooru Takahashi, Katsuhisa Yamazaki, Syuhei Moribe, Daisuke Yoshiba, Masami Fujimoto