Patents by Inventor Tadao Takikawa

Tadao Takikawa 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: 8163840
    Abstract: Disclosed is a heat-fusible electrostatic image developing toner which has an excellent balance between fixability at low temperatures and grindability and is excellent in glossiness after fixing. Also disclosed is a resin for toners. A polyester resin for toners which is obtained by polycondensing a polyol component and a polycarboxylic acid component is characterized by containing 20-100 weight % of one or more polyester resins (A1) having a storage elastic modulus from 2.5×103 Pa to 5×106 Pa at 150° C. wherein the molar average cohesive energy of the polyol component is between 7.0×104 and 1.4×105 J.
    Type: Grant
    Filed: April 21, 2011
    Date of Patent: April 24, 2012
    Assignee: Sanyo Chemical Industries, Ltd
    Inventors: Tadao Takikawa, Shuhei Yahiro
  • Publication number: 20110200931
    Abstract: [Problems] Disclosed is a heat-fusible electrostatic image developing toner which has an excellent balance between fixability at low temperatures and grindability and is excellent in glossiness after fixing. Also disclosed is a resin for toners. [Means for Solving Problems] A polyester resin for toners which is obtained by polycondensing a polyol component and a polycarboxylic acid component is characterized by containing 20-100 weight % of one or more polyester resins (A1) having a storage elastic modulus from 2.5×103 Pa to 5×106 Pa at 150° C. wherein the molar average cohesive energy of the polyol component is between 7.0×104 and 1.4×105 J.
    Type: Application
    Filed: April 21, 2011
    Publication date: August 18, 2011
    Applicant: Sanyo Chemical Industries, Ltd
    Inventors: Tadao Takikawa, Shuhei Yahiro
  • Patent number: 7951518
    Abstract: Disclosed is a heat-fusible electrostatic image developing toner which has an excellent balance between fixability at low temperatures and grindability and is excellent in glossiness after fixing. Also disclosed is a resin for toners. A polyester resin for toners which is obtained by polycondensing a polyol component and a polycarboxylic acid component is characterized by containing 20-100 weight % of one or more polyester resins (A1) having a storage elastic modulus from 2.5×103 Pa to 5×106 Pa at 150° C. wherein the molar average cohesive energy of the polyol component is between 7.0×104 and 1.4×105 J.
    Type: Grant
    Filed: December 10, 2004
    Date of Patent: May 31, 2011
    Assignee: Sanyo Chemical Industries, Ltd
    Inventors: Yasuhiro Ono, Masakazu Iwata, Takashi Akutagawa, Tsuyosi Izumi, Tadao Takikawa, Shuhei Yahiro
  • Patent number: 7531281
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: May 12, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7435521
    Abstract: A toner for developing an electrostatic image which has a small particle size essential for attaining a high-quality image, and can output a high-quality image excellent in frictional charging property and free from scumming. The toner for developing an electrostatic image has the volume average particle diameter of 2.0 ?m to 7.1 ?m and the surface condition of the toner is in scab form.
    Type: Grant
    Filed: December 28, 2004
    Date of Patent: October 14, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichiro Yagi, Hiroshi Yamada, Hiroshi Yamashita, Naohiro Watanabe, Tsunemi Sugiyama, Shigeru Emoto, Masami Tomita, Toshiki Nanya, Tadao Takikawa
  • Patent number: 7405000
    Abstract: Provided is a resin particle comprising a resin (a) and a filler (b) contained in the particle; the particle has a volume average particle diameter of from 0.1 to 300 ?m and a shape factor of from 110 to 300; the particle has an outer shell layer (S) comprising at least a portion of the filler (b); the layer (S) is at least 0.01 ?m thick and has a thickness that is ½ or less of the maximum inscribed circle radius of the particle cross section. When used as a toner resin, it is excellent in blade cleaning properties and wide in the fixation temperature range; when employed as a paint additive or a cosmetics additive, it is excellent in masking properties; when used as paper coating additive, it is excellent in ink retention; when utilized as an abrasive, it is excellent in abrasion.
    Type: Grant
    Filed: July 14, 2004
    Date of Patent: July 29, 2008
    Assignees: Sanyo Chemical Industries, Ltd, Ricoh Company, Ltd.
    Inventors: Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro, Yutaka Yoshida, Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura
  • Publication number: 20080138735
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Application
    Filed: October 31, 2007
    Publication date: June 12, 2008
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7384720
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Publication number: 20070281235
    Abstract: [PROBLEMS] Disclosed is a heat-fusible electrostatic image developing toner which has an excellent balance between fixability at low temperatures and grindability and is excellent in glossiness after fixing. Also disclosed is a resin for toners. [MEANS FOR SOLVING PROBLEMS] A polyester resin for toners which is obtained by polycondensing a polyol component and a polycarboxylic acid component is characterized by containing 20-100 weight % of one or more polyester resins (A1) having a storage elastic modulus from 2.5×103 Pa to 5×106 Pa at 150° C. wherein the molar average cohesive energy of the polyol component is between 7.0×104 and 1.4×105 J.
    Type: Application
    Filed: December 10, 2004
    Publication date: December 6, 2007
    Inventors: Yasuhiro Ono, Masakazu Iwata, Takashi Akutagawa, Tsuyoshi Izumi, Tadao Takikawa, Shuhei Yahiro
  • Patent number: 7241545
    Abstract: A toner has a storage elastic modulus (G?) of 500 Pa or more at a frequency of 1 Hz and temperature of 180° C., while the toner is obtained by dissolving or dispersing a toner composition in an organic solvent, further dispersing the solution or dispersion thereof in an aqueous medium containing fine resin particles as well as being reacted with a compound having an active hydrogen group, and removing the solvent from the obtained aqueous dispersion.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: July 10, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Masami Tomita, Shigeru Emoto, Shinichiro Yagi, Naohiro Watanabe, Tadao Takikawa
  • Patent number: 7217487
    Abstract: A toner has a storage elastic modulus (G?) of 500 Pa or more at a frequency of 1 Hz and temperature of 180° C., while the toner is obtained by dissolving or dispersing a toner composition in an organic solvent, further dispersing the solution or dispersion thereof in an aqueous medium containing fine resin particles as well as being reacted with a compound having an active hydrogen group, and removing the solvent from the obtained aqueous dispersion.
    Type: Grant
    Filed: August 7, 2006
    Date of Patent: May 15, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Masami Tomita, Shigeru Emoto, Shinichiro Yagi, Naohiro Watanabe, Tadao Takikawa
  • Patent number: 7166403
    Abstract: A toner capable of making compatible a transferring property, a fixing property and a cleaning property and forming a high-precision image. The toner comprises a binder resin and a colorant and is characterized in that the average circularity of the toner is at least 0.95, a ratio (D/S) between the total projection area (S) and the contact area (D) of the toner is 15% to 40%, and the contact area (D) is a total contact area between the toner and an object surface. The toner has such a shape as to be able to contact a latent image carrier with a proper contact area, has a high transferring rate and can prevent transferring dust.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: January 23, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura, Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro
  • Patent number: 7157201
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: January 2, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Publication number: 20060269860
    Abstract: A toner has a storage elastic modulus (G?) of 500 Pa or more at a frequency of 1 Hz and temperature of 180° C., while the toner is obtained by dissolving or dispersing a toner composition in an organic solvent, further dispersing the solution or dispersion thereof in an aqueous medium containing fine resin particles as well as being reacted with a compound having an active hydrogen group, and removing the solvent from the obtained aqueous dispersion.
    Type: Application
    Filed: August 7, 2006
    Publication date: November 30, 2006
    Inventors: Toshiki Nanya, Masami Tomita, Shigeru Emoto, Shinichiro Yagi, Naohiro Watanabe, Tadao Takikawa
  • Patent number: 7129013
    Abstract: A toner for developing latent electrostatic images is in the form of particles prepared by dissolving or dispersing each component of a composition in an organic solvent to form a solution or dispersion, the composition containing at least a resin reactive with a compound having an active hydrogen group, a compound having an active hydrogen group, a coloring agent, a releasing agent, and a graft polymer C of a polyolefin resin A on which a vinyl resin B has been at least partially grafted; dispersing the solution or dispersion in an aqueous medium; reacting the reactive resin with the compound having an active hydrogen group; removing the organic solvent during or after the step of reacting; and washing and drying particles formed by removing the organic solvent.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: October 31, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroto Higuchi, Masami Tomita, Fumihiro Sasaki, Shigeru Emoto, Naohito Shimota, Maiko Kondo, Takahiro Honda, Junichi Awamura, Shinichiro Yagi, Toshiki Nanya, Tadao Takikawa
  • Publication number: 20060165989
    Abstract: Provided is a resin particle comprising a resin (a) and a filler (b) contained in the particle; the particle has a volume average particle diameter of from 0.1 to 300 ?m and a shape factor of from 110 to 300; the particle has an outer shell layer (S) comprising at least a portion of the filler (b); the layer (S) is at least 0.01 ?m thick and has a thickness that is ½ or less of the maximum inscribed circle radius of the particle cross section. When used as a toner resin, it is excellent in blade cleaning properties and wide in the fixation temperature range; when employed as a paint additive or a cosmetics additive, it is excellent in masking properties; when used as paper coating additive, it is excellent in ink retention; when utilized as an abrasive, it is excellent in abrasion.
    Type: Application
    Filed: July 14, 2004
    Publication date: July 27, 2006
    Applicants: Sanyo Chemical Industries, Ltd., Ricoh Company, Ltd.
    Inventors: Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro, Yutaka Yoshida, Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura
  • Publication number: 20060154168
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.61 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Application
    Filed: December 12, 2005
    Publication date: July 13, 2006
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7056638
    Abstract: The present invention is directed to a toner for electrophotography that exhibits excellent hot offset resistance, storability, and glossiness and can obtain a high image-resolution and highly detailed images when used for energy saving apparatuses or as a color toner. The present invention is also directed to a developer, image-forming apparatus, and process cartridge containing such toner, and image-forming process using such toner. The toner of the present invention contains a resin and wax. The wax is dispersed within the resin in a shaped of fine particles to form a toner particle. In the toner particle, more dispersed wax particles are existed in a surface portion of the toner particle than a centric portion of the toner particle.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: June 6, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Toshiki Nanya, Fumihiro Sasaki, Shigeru Emoto, Shinichiro Yagi, Hiroto Higuchi, Naohiro Watanabe, Tadao Takikawa
  • Patent number: 7056636
    Abstract: A dry toner contains at least a toner binder, organic fine particles, a colorant, a wax, a charge control agent, and an external additive. The wax is concentrated in the vicinity of a toner core including the toner binder, colorant and wax. The organic fine particles adhere to the surface of the toner core to form a base toner-particle, the fine particle of charge control agent adhere to the surface of the base toner-particle, and the external additive is located on the surface thereof.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: June 6, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shinichiro Yagi, Shigeru Emoto, Tomoyuki Ichikawa, Naohito Shimota, Maiko Kondo, Tadao Takikawa
  • Publication number: 20050255399
    Abstract: A toner capable of making compatible a transferring property, a fixing property and a cleaning property and forming a high-precision image. The toner comprises a binder resin and a colorant and is characterized in that the average circularity of the toner is at least 0.95, a ratio (D/S) between the total projection area (S) and the contact area (D) of the toner is 15% to 40%, and the contact area (D) is a total contact area between the toner and an object surface. The toner has such a shape as to be able to contact a latent image carrier with a proper contact area, has a high transferring rate and can prevent transferring dust.
    Type: Application
    Filed: June 24, 2005
    Publication date: November 17, 2005
    Inventors: Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura, Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro