Patents by Inventor Yoshitaka Kawase

Yoshitaka Kawase 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: 7781139
    Abstract: A toner manufacturing method that allows production of toner having desired characteristics with stability in accordance with fusion emulsification technique for obtaining a toner by granulating a resin kneaded product while dispersing it in an aqueous medium. A resin kneaded product containing at least a binder resin and a colorant is mixed with a dispersant/water-containing aqueous medium. The resultant admixture is stirred by an stirring apparatus including a screen with an admixture discharge hole disposed internally of a vessel and a rotor disposed in an stirring space created by the screen.
    Type: Grant
    Filed: December 4, 2006
    Date of Patent: August 24, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Satoru Ariyoshi, Yoshitaka Kawase, Keiichi Kikawa, Katsuru Matsumoto
  • Publication number: 20100209145
    Abstract: A capsule toner capable of enhancing low temperature fixation property without impairing preservation property under a high temperature environment, a two-component developer, and an image forming apparatus are provided. The capsule toner is constituted of toner particles having toner base particles and a coating layer for coating the surface thereof. The toner base particle includes styrene-acrylic resin or polyester resin as a binder resin, and the coating layer includes styrene-acrylic resin or polyester resin. The capsule toner contains 0.05% by weight or more and 0.70% by weight or less of volatile plasticizer based on a total amount of the capsule toner.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 19, 2010
    Inventors: Keiichi KIKAWA, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Yoshinori Mutoh, Takashi Hara
  • Publication number: 20100159374
    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: Application
    Filed: December 14, 2009
    Publication date: June 24, 2010
    Inventors: Yoshinori Mutoh, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Keiichi Kikawa, Takashi Hara
  • Publication number: 20100104324
    Abstract: A method for manufacturing a resin-layer coated toner is provided. The method for manufacturing the resin-layer coated toner uses a rotary stirring apparatus including a circulating section, a temperature regulation section, a spraying section and an exhausting section, sprays a liquid substance to particles of toner materials and particles of coating materials in a fluidized state to plasticize such particles from a spraying section by carrier gas and gasifies the liquid, circulates the carrier gas in the powder passage and continuously exhausts the carrier gas including the gasified substance through the exhausting section to the outside of the powder passage, and pressure P1 in the powder passage and pressure P0 outside the powder passage satisfy the following formula (1): 0 atm<(Pressure P1 in the powder passage?Pressure P0 outside the powder passage)?0.3 atm??(1).
    Type: Application
    Filed: October 26, 2009
    Publication date: April 29, 2010
    Inventors: Yoshitaka Kawase, Takashi Hara, Yoshiaki Akazawa
  • Patent number: 7691553
    Abstract: A kneaded material obtained by heating and melt-kneading a toner composition and a water-based medium containing water are put into a container of a granulating apparatus, and heated by a heater while agitating, to disperse the kneaded material into the water-based medium in its softened state. A temperature at which a loss tangent value of the kneaded material reaches a predetermined loss tangent value A, specifically, 0.5 or more and less than 5.0, is inputted to a granulating temperature input section as a setting granulating temperature T1. The heater is then controlled by a control section so that a granulating temperature as a temperature of the water-based medium measured by a thermometer reaches the setting granulating temperature T1 inputted to the input section. Accordingly, the granulating temperature as a temperature of the water-based medium, and thus a temperature of the kneaded material in the water-based medium is adjusted to T1.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: April 6, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Satoru Ariyoshi, Yoshitaka Kawase, Yoritaka Tsubaki
  • Publication number: 20100080629
    Abstract: A method for manufacturing a toner is provided. In a fine resin particle adhering step S1b, fine resin particles adhere to toner base particle surfaces in a powder passage. In a spraying step S3c, flowing toner base particles and fine resin particles are sprayed with a substance in liquid form for plasticizing those particles. In a film-forming step S3d, toner base particles and fine resin particles are circulated repeatedly in the powder passage until fine resin particles adherent to toner base particles are shaped into a film. In the spraying step S3c, the substance in liquid form is sprayed in such a manner that the LEL concentration coefficient within the powder passage falls in a range of from 0.07 to 8.12.
    Type: Application
    Filed: September 29, 2009
    Publication date: April 1, 2010
    Inventors: Takashi HARA, Yoshitaka Kawase, Yoshiaki Akazawa
  • Publication number: 20100061767
    Abstract: A method for manufacturing a toner is provided. The method for manufacturing a toner uses a rotary stirring apparatus. The rotary stirring apparatus includes at least a circulation section, a temperature regulation section and a spraying section composed of a two-fluid nozzle. The two-fluid nozzle includes a liquid pipe and an air pipe, the liquid pipe is inserted in the air pipe such that an axis of the liquid pipe coincides with an axis of the air pipe, and at least a part of the liquid pipe and the air pipe is fixed such that the centers of those pipes do not move. A substance in liquid form is sprayed in constant rate from the two-fluid nozzle while regulating temperature and circulating the toner base particles and the fine resin particles in a powder passage, thereby forming a film on the surface of the toner base particle.
    Type: Application
    Filed: September 10, 2009
    Publication date: March 11, 2010
    Inventors: Yoshitaka Kawase, Takeshi Hara, Yoshiaki Akazawa
  • Publication number: 20090297224
    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: Application
    Filed: May 29, 2009
    Publication date: December 3, 2009
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Yoshitaka Kawase, Saori Yamada, Yoshiaki Akazawa, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa, Takashi Hara
  • Publication number: 20090297225
    Abstract: A toner whose flowability, chargeability and fixing property are enhanced, a developer, a developing device and an image forming apparatus are provided. The toner comprises a toner particle in which a shell layer is formed on a surface of a core particle, and external additive, where (1) the shell layer is formed in a film on the surface of the core particle, (2) a shape factor SF-2 is 120 or more and 140 or less, and (3) a BET specific surface area measured by the BET method is 1.2 m2/cm3 or more and 4.0 m2/cm3 or less. The developer containing such a toner is filled into the developing device in the image forming apparatus in order to form an image.
    Type: Application
    Filed: May 29, 2009
    Publication date: December 3, 2009
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Saori Yamada, Yoshitaka Kawase, Yoshiaki Akazawa
  • Patent number: 7608379
    Abstract: A toner of excellent anti-hot offsetting property, with no variety of the charging performance and suitable as a toner for the development of electrostatic images, and a manufacturing method thereof are provided. At first, a crosslinked resin at least containing a tetrahydrofuran insoluble component and a colorant are dry-kneaded. Next, the obtained kneaded resin product is mixed with an aqueous dispersant solution prepared in advance and they are heated, to form colorant-containing resin particles in a liquid mixture of the kneaded resin product and the aqueous dispersant solution. Then, the liquid mixture is cooled and the colorant-containing resin particles are separated from the liquid mixture.
    Type: Grant
    Filed: August 18, 2006
    Date of Patent: October 27, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshitaka Kawase, Satoru Ariyoshi, Katsuru Matsumoto, Yoshinori Yamamoto
  • Publication number: 20090098475
    Abstract: There are provided a toner, a method of manufacturing the toner, a two-component developer, a developing device, and an image forming apparatus, which are excellent in a charge rising property, environmental stability, and life stability during printing and which cause less fogging. The toner contains a core particle containing binder resin and colorant, and a coating layer which contains resin and a charge control agent and is formed on a surface of the core particle. At least a part of the resin contained in the coating layer is melt-bonded to the core particle, and the charge control agent is dispersed and immobilized in the coating layer. The dispersed charge control agent has a dispersion diameter of less than 1 ?m.
    Type: Application
    Filed: October 10, 2008
    Publication date: April 16, 2009
    Inventors: Saori YAMADA, Yoshitaka KAWASE, Yoshiaki Akazawa
  • Publication number: 20090011357
    Abstract: A toner is a capsule particle including a toner particle composed of a core particle that is a resin particle and shell particles covering the surface of the core particle. The toner is manufactured by controlling the particle size so that the toner particles have a volume average particle size of 4.0 or more and 8.0 ?m or less, and a ratio of a toner particle having a number average particle size of 3.0 ?m or less of 8% by number or more and 25% by number or less to the entirety of the toner particles. The shell particles are melt-bonded to the core particle to be integrated therewith.
    Type: Application
    Filed: July 7, 2008
    Publication date: January 8, 2009
    Inventors: Yoshitaka Kawase, Masao Suzuki
  • Publication number: 20080166156
    Abstract: A toner excellent in temporal stability is provided which toner is capable of maintaining good cleaning property stably for a long period of time and whose surface is provided with a coating layer having an effect of preventing toner aggregation. There are also provided a method of manufacturing the toner, a two-component developer, a developing apparatus, and an image forming apparatus. The toner has a core particle containing a binder resin and a colorant and a coating layer which contains fine resin particles and are formed on surfaces of the core particles. The coating layers are formed by partially fusing the fine resin particles to at least either the core particle or adjacent fine resin particles.
    Type: Application
    Filed: January 3, 2008
    Publication date: July 10, 2008
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Yoshitaka Kawase
  • Patent number: 7285367
    Abstract: A method of manufacturing a toner for developing static charges in an aqueous system is provided which includes preparation step for a resin kneaded product, preparation step for the aqueous dispersion of a less water-soluble alkaline earth metal salt, preparation step for synthetic resin particles, removal step for the less water-soluble alkaline earth metal salt, and separation-cleaning-drying step. At preparation step S3 for synthetic resin, an ionic material for decomposing the less water-soluble alkaline earth metal salt is admixed with a mixture of the resin kneaded product and the aqueous dispersion of the less water-soluble alkaline earth metal salt.
    Type: Grant
    Filed: March 7, 2005
    Date of Patent: October 23, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshitaka Kawase, Takanori Kamoto, Satoru Ariyoshi
  • Publication number: 20070224533
    Abstract: A kneaded material obtained by heating and melt-kneading a toner composition and a water-based medium containing water are put into a container of a granulating apparatus, and heated by a heater while agitating, to disperse the kneaded material into the water-based medium in its softened state. A temperature at which a loss tangent value of the kneaded material reaches a predetermined loss tangent value A, specifically, 0.5 or more and less than 5.0, is inputted to a granulating temperature input section as a setting granulating temperature T1. The heater is then controlled by a control section so that a granulating temperature as a temperature of the water-based medium measured by a thermometer reaches the setting granulating temperature T1 inputted to the input section. Accordingly, the granulating temperature as a temperature of the water-based medium, and thus a temperature of the kneaded material in the water-based medium is adjusted to T1.
    Type: Application
    Filed: March 26, 2007
    Publication date: September 27, 2007
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Satoru Ariyoshi, Yoshitaka Kawase, Yoritaka Tsubaki
  • Publication number: 20070128537
    Abstract: A toner manufacturing method that allows production of toner having desired characteristics with stability in accordance with fusion emulsification technique for obtaining a toner by granulating a resin kneaded product while dispersing it in an aqueous medium. A resin kneaded product containing at least a binder resin and a colorant is mixed with a dispersant/water-containing aqueous medium. The resultant admixture is stirred by an stirring apparatus including a screen with an admixture discharge hole disposed internally of a vessel and a rotor disposed in an stirring space created by the screen.
    Type: Application
    Filed: December 4, 2006
    Publication date: June 7, 2007
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Satoru Ariyoshi, Yoshitaka Kawase, Keiichi Kikawa, Katsuru Matsumoto
  • Publication number: 20070065746
    Abstract: A toner of excellent anti-hot offsetting property, with no variety of the charging performance and suitable as a toner for the development of electrostatic images, and a manufacturing method thereof are provided. At first, a crosslinked resin at least containing a tetrahydrofuran insoluble component and a colorant are dry-kneaded. Next, the obtained kneaded resin product is mixed with an aqueous dispersant solution prepared in advance and they are heated, to form colorant-containing resin particles in a liquid mixture of the kneaded resin product and the aqueous dispersant solution. Then, the liquid mixture is cooled and the colorant-containing resin particles are separated from the liquid mixture.
    Type: Application
    Filed: August 18, 2006
    Publication date: March 22, 2007
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Yoshitaka Kawase, Satoru Ariyoshi, Katsuru Matsumoto, Yoshinori Yamamoto
  • Patent number: 7141347
    Abstract: A toner manufacturing process capable of providing a toner with uniform charge amounts. A mixture of a synthetic resin having an acidic leaving group and a coloring agent as essential components is emulsified in an aqueous solution to produce synthetic resin particles containing the coloring agent. If desired, the resin particles are further aggregated to form aggregated resin particles. The synthetic resin particles are then separated, washed and dried. The washing of the toner particles is conducted using a washing water prepared by dissolving carbon dioxide in water with a conductivity of not more than 20 ?S/cm.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: November 28, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yoshitaka Kawase
  • Publication number: 20050202336
    Abstract: A method of manufacturing a toner for developing static charges in an aqueous system is provided which includes preparation step for a resin kneaded product, preparation step for the aqueous dispersion of a less water-soluble alkaline earth metal salt, preparation step for synthetic resin particles, removal step for the less water-soluble alkaline earth metal salt, and separation-cleaning-drying step. At preparation step S3 for synthetic resin, an ionic material for decomposing the less water-soluble alkaline earth metal salt is admixed with a mixture of the resin kneaded product and the aqueous dispersion of the less water-soluble alkaline earth metal salt.
    Type: Application
    Filed: March 7, 2005
    Publication date: September 15, 2005
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Yoshitaka Kawase, Takanori Kamoto, Satoru Ariyoshi
  • Publication number: 20040209182
    Abstract: A toner manufacturing process capable of providing a toner with uniform charge amounts. A mixture of a synthetic resin having an acidic leaving group and a coloring agent as essential components is emulsified in an aqueous solution to produce synthetic resin particles containing the coloring agent. If desired, the resin particles are further aggregated to form aggregated resin particles. The synthetic resin particles are then separated, washed and dried. The washing of the toner particles is conducted using a washing water prepared by dissolving carbon dioxide in water with a conductivity of not more than 20 &mgr;S/cm.
    Type: Application
    Filed: April 15, 2004
    Publication date: October 21, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Yoshitaka Kawase