Patents by Inventor Keiichi Kikawa

Keiichi Kikawa 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: 8389193
    Abstract: There are provided a toner manufacturing method of manufacturing a toner which has excellent characteristics such as fluidity and preservation stability and in which a resin layer having uniform thickness is formed on a surface of tone core particle, a toner obtained by a method thereof, a one-component developer, a two-component developer, a developing device, and an image forming apparatus. By using a toner manufacturing apparatus, a stirring step S3 is performed, and during rotation of a rotary shaft section, after a completion of inputting the fine resin particles into a powder passage, and within a period satisfying 1.7?(load F?load F0)/(load Fcore?load F0)?5.7, a spraying step S4 is started.
    Type: Grant
    Filed: March 24, 2010
    Date of Patent: March 5, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Hara, Yoshitaka Kawase, Yoshiaki Akazawa, Yoritaka Tsubaki, Keiichi Kikawa, Yoshinori Mutoh
  • Patent number: 8389195
    Abstract: A capsule toner achieving both low temperature fixability and hot offset resistance, and a method of manufacturing the capsule toner are provided. A capsule toner includes a toner base particle containing a binder resin and a colorant, and a resin coating layer formed on a surface of the toner base particle. The resin coating layer includes a film of plural fine resin particles having different complex viscosities. The plural fine resin particles include first fine resin particles having complex viscosity at a softening temperature of the toner base particles of 5.0×102 Pa·s or more and 1.0×103 Pa·s or less, and second fine resin particles having complex viscosity at a softening temperature of the toner base particles of 1.0×104 Pa·s or more and 1.0×105 Pa·s or less.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: March 5, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoritaka Tsubaki, Yoshitaka Kawase, Keiichi Kikawa, Yoshinori Mutoh, Takashi Hara, Yoshiaki Akazawa
  • Patent number: 8389194
    Abstract: A toner manufacturing method, a toner obtained by the method, a one-component developer, a two-component developer, a developing device and an image forming apparatus are provided. By using a toner manufacturing apparatus including a powder passage, a spraying section for spraying a predetermined substance in the powder passage and a rotary stirring section, provided in the powder passage, and stirring particles in the powder passage to apply impact force to the particles so that the particles are fluidized in the powder passage, performed are a stirring step S3 of fluidizing toner core particles with fine inorganic particles adhering to the surfaces thereof and fine resin particles in the powder passage as the powder by the rotary stirring section, and a spraying step S5 of spraying a volatile liquid which softens fine resin particles as a predetermined substance by the spraying section.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: March 5, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa, Takashi Hara
  • Patent number: 8304158
    Abstract: A method for manufacturing a toner includes a pre-mixing step and a coating step. In the pre-mixing step, a secondary aggregate of the fine resin particles is disaggregated, while toner base particles and fine resin particles are mixed and stirred using a rotary stirring apparatus. Thus obtained disaggregated fine resin particles are fixed to the surface of the toner base particle. Thus, a fine resin particle-fixed toner is obtained. The rotary stirring apparatus includes a rotary stirring section, a temperature regulation section, a circulating section, and a spraying section. In the coating step, a liquid is sprayed to the fine resin particle-fixed toner with the spraying section using the rotary stirring apparatus. Thus, a film of the fine resin particles is formed. In the pre-mixing step and the coating step, temperature regulation is conducted in the temperature regulation section.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: November 6, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinori Mutoh, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Keiichi Kikawa, Takashi Hara
  • Patent number: 8197999
    Abstract: A method for manufacturing a toner is provided. The method for manufacturing a toner uses a rotary stirring apparatus that includes a circulating section for repeatedly performing circulation in a powder passage having a rotary stirring chamber and a circulation tube to return to the rotary stirring chamber by a rotary stirring section having a rotary disc around which rotary blades are installed and a rotary shaft, and a temperature adjusting section provided at least on a part of the powder passage for adjusting temperatures in the powder passage and of the rotary stirring section to a predetermined temperature, and includes a temperature adjusting step; a fine resin particle adhering step; a spraying step; and a film-forming step. The temperature in the powder passage is adjusted to the predetermined temperature by the temperature adjusting section at the fine resin particle adhering step, the spraying step, and the film-forming step.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: June 12, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshitaka Kawase, Saori Yamada, Yoshiaki Akazawa, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa, Takashi Hara
  • Patent number: 8187783
    Abstract: A method of manufacturing a toner in which uneven distribution of toner ingredients by subjecting them to fine dispersion is prevented and which is excellent in transferability, cleaning properties, anti-filming properties, anti-blocking properties, high-temperature offset resisting properties and transparency is provided. Melt-kneaded substances include binder resins, colorants and release agents, respectively. The colorant and the release agent are dispersed in the binder resin. The melt-kneaded substance is negatively charged by an anionic dispersant, whereas the melt-kneaded substance is positively charged by a cationic dispersant. An aggregate is formed by heteroaggregation of the melt-kneaded substances. The aggregate is fused by heating and formed into a spherical toner.
    Type: Grant
    Filed: July 2, 2008
    Date of Patent: May 29, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keiichi Kikawa, Yasuhiro Shibai, Katsuru Matsumoto
  • Patent number: 8163458
    Abstract: A toner capable of forming high quality images of excellent image reproducibility at high definition and high resolution, being decreased for the bleed-out of a wax ingredient to the surface, causing less filming to a photoreceptor and offset phenomenon in a high temperature region, is provided. The toner is manufactured by a method including a preliminary pulverizing step of pulverizing a melt-kneaded product of toner raw materials in a liquid to obtain a coarse powder slurry containing a coarse toner powder, a finely pulverizing step of passing the coarse powder slurry through a pressure resistant nozzle under heating and pressurization thereby further pulverizing the coarse toner powder to obtain a fine powder slurry containing a fine toner powder and in a heated and pressurized state, a cooling step of cooling the fine powder slurry, and a depressurizing step of depressurizing the fine powder slurry.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: April 24, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keiichi Kikawa, Katsuru Matsumoto
  • Patent number: 8097395
    Abstract: A method of manufacturing toner particles capable of decreasing the manufacturing costs by simplifying the manufacturing apparatus and by decreasing the number of the steps, as well as to provide toner particles, a two-component developer, a developing apparatus and an image forming apparatus are provided. A high-pressure homogenizer is constituted by a tank, a feed pump, a high-pressure pump, a heat exchanger, a nozzle, a first depressurizing module, a cooling unit, a second depressurizing module and a take-out port arranged in this order. A flow path constituted in the first depressurizing module has a straight portion tilted with respect to a direction in which the aqueous slurry passes and a portion for relaxing the flow of the aqueous slurry.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: January 17, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Katsuru Matsumoto, Keiichi Kikawa, Nobuhiro Maezawa
  • Patent number: 8092968
    Abstract: The toner includes a plurality of toner particles containing a binder resin and a colorant. In toner particles, according to measurement by a flow particle image analyzer, the content of small size particles having a circle-equivalent diameter of 0.5 to 2.0 ?m is 5% by number or less based on the entire toner particles, the content of medium size particles having a circle-equivalent diameter of more than 2.0 ?m and 4.0 ?m or less is 20% by number or more and 30% by number or less based on the entire toner particles, and the content of large size particles having a circle-equivalent diameter of more than 4.0 ?m and 6.0 ?m or less is 50% by number or more and 70% by number or less based on the entire toner particles, and the shape factor of the toner particles SF1 is 130 or more and 140 or less.
    Type: Grant
    Filed: March 13, 2009
    Date of Patent: January 10, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keiichi Kikawa, Ayae Nagaoka, Katsuru Matsumoto
  • Patent number: 8067143
    Abstract: A functional particle is manufactured by a method including an aggregating step, a depressurizing step, and a cooling step. In the aggregating step, the functional particle is obtained by flowing a mixed slurry containing a core particle and a shell particle through a coiled pipeline while heating the mixed slurry to a glass transition temperature or higher of the core particle, to deposit the shell particles on the surface of the core particle. In the depressurizing step, the grain size of the functional particle is controlled and the coarse particle is pulverized to make the grain size of the functional particles uniform. In the cooling step, re-aggregation of the functional particles with unified grain size is prevented.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: November 29, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keiichi Kikawa, Katsuru Matsumoto, Nobuhiro Maezawa
  • Patent number: 8021817
    Abstract: A toner in form of aggregate of resin-containing particles is manufactured by aggregating the resin-containing particles which contain binder resin and the colorant, with the aid of an aggregate dispersant containing a polymer in which anionic polar groups are bonded to a main chain. To be specific, salt of divalent or higher valent metal is added to a slurry of the resin-containing particles so that a metal ion and the anionic polar group are bonded to each other, and a temperature of the slurry is increased so that a bond between the anionic polar group and a water molecule is broken. This decreases water-solubility of the polymer so that the resin-containing particles are aggregated.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: September 20, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keiichi Kikawa, Katsuru Matsumoto, Yasuhiro Shibai
  • Publication number: 20110177451
    Abstract: A method for manufacturing a capsule toner, capable of obtaining a capsule toner including a coating layer having uniform thickness at high yield is provided. The method for manufacturing a capsule toner includes a fine resin particle adhering step of adhering fine resin particles to surfaces of toner base particles, a spraying step of spraying a spray liquid for plasticizing the toner base particles and the fine resin particles, while fluidizing the toner base particles and the fine resin particles, and a film-forming step of fluidizing the toner base particles and the fine resin particles until the fine resin particles adhered to the surfaces of the toner base particles are softened to form a film. In the spraying step, ultrasonic vibration is applied to set a number average liquid-droplet diameter of the spray liquid to less than 10 ?m.
    Type: Application
    Filed: January 19, 2011
    Publication date: July 21, 2011
    Inventors: Yoritaka TSUBAKI, Yoshitaka Kawase, Keiichi Kikawa, Yoshinori Mutoh, Takashi Hara, Yoshiaki Akazawa
  • Publication number: 20110171574
    Abstract: A method for manufacturing a capsule toner having improved preservability with no deterioration in low-temperature fixability is provided. The method for manufacturing a capsule toner includes a mixed fine resin particle adhering step of adhering mixed fine resin particles including crystalline polyester fine resin particles and amorphous fine resin particles to surfaces of toner base particles to form mixed fine resin particle-adhered particles, a spraying step of spraying a mixed solution of a liquid for plasticizing the toner base particles and the mixed fine resin particles and a crystal nucleating agent, while fluidizing the mixed fine resin particle-adhered particles, and a film-forming step of making a film of the mixed fine resin particles by impact force so that the film is a resin coating layer on the surfaces of the toner base particles.
    Type: Application
    Filed: January 7, 2011
    Publication date: July 14, 2011
    Inventors: Takashi HARA, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa
  • Patent number: 7955771
    Abstract: A toner for electrostatic image development, comprising an organic pigment and a binding resin, and satisfying the formula (I): 1?R/A?0.014C??(I), wherein A represents an entire area of a graph (x-axis: wavelength of a visible radiation region (380 to 780 nm), y-axis: transmittance (0 to 100%)) showing a spectral transmittance curve of a supernatant fluid, the supernatant fluid being obtained by subjecting the toner to an extraction process, the extraction process using a supercritical fluid; R represents an area determined by a Rectangular method on the basis of a spectral transmittance curve in the graph; and C represents a concentration (wt %) of the organic pigment in the toner, the organic pigment having a particle diameter of 1/10 to ½ ( 1/10 to 4/7 when the organic pigment is an organic yellow pigment) of a maximum absorption wavelength of the organic pigment, and the toner having a haze of 16 or less.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: June 7, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keiichi Kikawa, Yasuhiro Shibai, Yoritaka Tsubaki
  • Publication number: 20110111338
    Abstract: A toner manufacturing method is provided. The toner manufacturing method includes a step of adhering fine resin particles whose volume average particle size is 5% or more and 17% or less of a volume average particle size of toner base particles, to surfaces of the toner base particles; and a step of plasticizing the toner base particles and the fine resin particles by adding mechanical impact thereto while spraying lower alcohol, and fusing the fine resin particles to the surfaces of the toner base particles to form a plurality of projections of the fine resin particles, on the surfaces of the toner base particles. Surface coverage of the surfaces of the toner base particles with the projections is 10% or more and 50% or less.
    Type: Application
    Filed: November 8, 2010
    Publication date: May 12, 2011
    Inventors: Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa, Takashi Hara
  • Patent number: 7931876
    Abstract: The invention provides a method and an apparatus for manufacturing a developer, which can manufacture a developer having a uniform and fine particle shape in a narrow particle size distribution and having a coloring agent highly dispersed therein at the primary particle level, the method and apparatus at the same time enabling continuous and efficient production without opening and closing a reactor. The method comprises the steps of: dissolving a binding resin component in a supercritical or subcritical fluid so that the binding resin component is blended with a coloring agent component; and reducing the solubility of the binding resin component in the supercritical or subcritical fluid so that the binding resin component is precipitated in the form of particles with the coloring agent component dispersed in the interior thereof.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: April 26, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shinichi Nakano, Yasuhiro Shibai, Keiichi Kikawa
  • Publication number: 20110069992
    Abstract: A method of manufacturing toner particles capable of decreasing the manufacturing costs by simplifying the manufacturing apparatus and by decreasing the number of the steps, as well as to provide toner particles, a two-component developer, a developing apparatus and an image forming apparatus are provided. A high-pressure homogenizer is constituted by a tank, a feed pump, a high-pressure pump, a heat exchanger, a nozzle, a first depressurizing module, a cooling unit, a second depressurizing module and a take-out port arranged in this order. A flow path constituted in the first depressurizing module has a straight portion tilted with respect to a direction in which the aqueous slurry passes and a portion for relaxing the flow of the aqueous slurry.
    Type: Application
    Filed: November 30, 2010
    Publication date: March 24, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Katsuru Matsumoto, Keiichi Kikawa, Nobuhiro Maezawa
  • Publication number: 20110070541
    Abstract: A capsule toner achieving both low temperature fixability and hot offset resistance, and a method of manufacturing the capsule toner are provided. A capsule toner includes a toner base particle containing a binder resin and a colorant, and a resin coating layer formed on a surface of the toner base particle. The resin coating layer includes a film of plural fine resin particles having different complex viscosities. The plural fine resin particles include first fine resin particles having complex viscosity at a softening temperature of the toner base particles of 5.0×102 Pa·s or more and 1.0×103 Pa·s or less, and second fine resin particles having complex viscosity at a softening temperature of the toner base particles of 1.0×104 Pa·s or more and 1.0×105 Pa·s or less.
    Type: Application
    Filed: September 14, 2010
    Publication date: March 24, 2011
    Inventors: Yoritaka Tsubaki, Yoshitaka Kawase, Keiichi Kikawa, Yoshinori Mutoh, Takashi Hara, Yoshiaki Akazawa
  • Patent number: 7910279
    Abstract: A method of manufacturing aggregate particles capable of obtaining aggregate particles having high mechanical strength, small particle size, with narrow particle size distribution width by preventing interfusion of bubbles in the aggregate particles during stirring is provided. Aggregate particles are manufactured by stirring a resin particle slurry including resin particles dispersed in an aqueous medium and contained in a stirring vessel by a stirring section having a impeller and two or more screen members disposed so as to surround the impeller in the stirring vessel and each formed with a plurality of slits and aggregating the resin particles.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: March 22, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Nobuhiro Maezawa, Katsuru Matsumoto, Keiichi Kikawa
  • Publication number: 20110059394
    Abstract: There are provided a capsule toner, a two-component developer, and a capsule toner manufacturing method. The capsule toner in which a resin coating layer made of fine release-agent particles and fine resin particles is made on the surfaces of toner base particles, and thus excellent offset resistance without impairing blocking resistance can be obtained. The capsule toner includes toner base particles containing a binder resin and a colorant, and a resin coating layer made of fine release-agent particles and fine resin particles, for covering the surfaces of the toner base particles. The fine release-agent particles are dispersed in the resin coating layer.
    Type: Application
    Filed: September 9, 2010
    Publication date: March 10, 2011
    Inventors: Yoshinori MUTOH, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Keiichi Kikawa, Takashi Hara