Patents by Inventor Kazunobu Watanabe

Kazunobu Watanabe 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: 12221517
    Abstract: The present invention provides a molding precursor for a fiber-reinforced polyimide resin molded article, which is formed by impregnating a functional fiber with an addition-reaction type polyimide resin. The molding precursor has a melt viscosity in the range of 300 to 3200 kPa·s under conditions of keeping for 1 to 10 minutes at a temperature 5 to 20° C. lower than the thickening-start temperature so as to effectively prevent a fiber-reinforced polyimide resin molded article from warping. The present invention provides also a method for producing the molding precursor.
    Type: Grant
    Filed: December 9, 2019
    Date of Patent: February 11, 2025
    Assignee: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kouta Segami, Kazunobu Watanabe, Yusuke Kobayashi
  • Publication number: 20230235123
    Abstract: An addition reaction type polyimide resin molded body having a thickness of 5 mm or more, with a number of defects having a size of 0.5 mm or more present on the entire surface of the molded body being 1 per 100 cm2 or less. The addition reaction type polyimide resin molded body is formed by: holding a prepolymer of an addition reaction type polyimide resin at a temperature equal to or higher than a viscosity increase starting temperature of the addition reaction type polyimide resin and increasing a melt viscosity at a temperature lower by 10° C. than the viscosity increase starting temperature to 70 to 900 kPa·s; grinding and mixing the addition reaction type polyimide resin to form a molding precursor; and shaping the molding precursor at a temperature equal to or higher than a heat-curing temperature of the addition reaction type polyimide resin.
    Type: Application
    Filed: June 7, 2021
    Publication date: July 27, 2023
    Applicant: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kouta SEGAMI, Kazunobu WATANABE, Yusuke KOBAYASHI
  • Publication number: 20220049060
    Abstract: The present invention provides a molding precursor for a fiber-reinforced polyimide resin molded article, which is formed by impregnating a functional fiber with an addition-reaction type polyimide resin. The molding precursor has a melt viscosity in the range of 300 to 3200 kPa·s under conditions of keeping for 1 to 10 minutes at a temperature 5 to 20° C. lower than the thickening-start temperature so as to effectively prevent a fiber-reinforced polyimide resin molded article from warping. The present invention provides also a method for producing the molding precursor.
    Type: Application
    Filed: December 9, 2019
    Publication date: February 17, 2022
    Applicant: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kouta SEGAMI, Kazunobu WATANABE, Yusuke KOBAYASHI
  • Publication number: 20200353727
    Abstract: A fiber-reinforced laminate including at least a layer of woven fibers and a layer of short fiber-containing resin composition, wherein the short fiber-containing resin composition is present in gaps formed by crossing fiber bundles composing the woven fibers. Also disclosed is a method for producing the laminate.
    Type: Application
    Filed: November 27, 2018
    Publication date: November 12, 2020
    Applicant: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kouta SEGAMI, Kazunobu WATANABE, Toshinori ENOKIDO, Yusuke KOBAYASHI
  • Publication number: 20200165451
    Abstract: A composition containing 40 to 350 parts by weight of a functional fiber and 100 to 600 parts by weight of an inorganic microparticulate filler having an average particle diameter of less than 15 ?m per 100 parts by weight of the addition-reaction type polyimide resin. Also disclosed is a sliding member including the composition and a method for producing a molded article including the composition.
    Type: Application
    Filed: April 11, 2018
    Publication date: May 28, 2020
    Applicant: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Toshinori ENOKIDO, Kazunobu WATANABE, Kouta SEGAMI, Yusuke KOBAYASHI
  • Publication number: 20190293121
    Abstract: A structure including a sliding layer that is formed on a roughened surface of a substrate and that has an excellent slidability, and a method for producing the structure. The sliding layer is formed of a powder of a carbon-composition-containing resin composition filled in at least concavities of roughness on the roughened surface.
    Type: Application
    Filed: June 1, 2017
    Publication date: September 26, 2019
    Applicant: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kazunobu WATANABE, Toshinori ENOKIDO, Kouta SEGAMI, Yusuke KOBAYASHI
  • Patent number: 10406765
    Abstract: A fiber-reinforced polyimide resin molded article and a production process therefor. After a prepolymer of an addition reaction type polyimide resin and functional fibers are dispersed and kneaded together, the kneaded product is kept at a temperature not lower than the heat curing start temperature of the reaction type polyimide resin for a fixed amount of time or mixed with a thickener to increase its viscosity, and shaped at a temperature not lower than the heat curing start temperature of the reaction type polyimide resin to obtain a molded article having excellent sliding performance with a limit PV value of not less than 3,000 kPa·m/s and excellent shape stability during molding and containing the functional fibers dispersed in the polyimide resin.
    Type: Grant
    Filed: September 14, 2015
    Date of Patent: September 10, 2019
    Assignee: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kazunobu Watanabe, Toshinori Enokido, Kouta Segami, Yuusuke Kobayashi
  • Publication number: 20170252986
    Abstract: A fiber-reinforced polyimide resin molded article and a production process therefor. After a prepolymer of an addition reaction type polyimide resin and functional fibers are dispersed and kneaded together, the kneaded product is kept at a temperature not lower than the heat curing start temperature of the reaction type polyimide resin for a fixed amount of time or mixed with a thickener to increase its viscosity, and shaped at a temperature not lower than the heat curing start temperature of the reaction type polyimide resin to obtain a molded article having excellent sliding performance with a limit PV value of not less than 3,000 kPa·m/s and excellent shape stability during molding and containing the functional fibers dispersed in the polyimide resin.
    Type: Application
    Filed: September 14, 2015
    Publication date: September 7, 2017
    Applicant: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kazunobu WATANABE, Toshinori ENOKIDO, Kouta SEGAMI, Yuusuke KOBAYASHI
  • Patent number: 8765038
    Abstract: A method of feeding a composite molten resin capable of easily forming a multi-kind-multi-layer preform. An apparatus for feeding the composite molten resin has a nozzle portion which includes an outer discharge port in which an outermost annular flow path through which a main layer-forming molten resin flows, meets an outer annular flow path through which a sub-layer-forming molten resin flows inside of the outermost annular flow path; and an inner discharge port in which a shell layer-forming molten resin annularly flowing inside of the outer conflux path, meets the core layer-forming molten resin flowing inside the shell layer; the outer discharge port and the inner discharge port being arranged in this order from the downstream toward the upstream in a direction in which the molten resins flow; wherein provision is made of a shaft-like opening/closing valve for opening and closing the inner discharge port, and a gear pump for intermittently discharging the sub-layer-forming molten resin.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: July 1, 2014
    Assignee: Toyo Seikan Kaisha, Ltd.
    Inventors: Norihisa Hirota, Kazunobu Watanabe, Yutaka Asano, Jotaro Nagao
  • Patent number: 8157555
    Abstract: An extrusion feed device for a composite resin capable of forming a composite resin extruded material having a variety of layer configurations not necessarily symmetrical. A plurality of cylindrical flow passages (3) and (4) for feeding a molten resin, an opening/closing valve (7) capable of opening/closing a center flow passage (36) and a cylindrical flow passage (4a), and a center opening/closing valve (39) capable of opening/closing the center flow passage are provided at the upstream side end part (2a) of a discharge passage (2) for delivering the composite resin extruded material. A main resin (30a) forming an outside layer is always fed from the cylindrical flow passage (3), and the other molten resin (30b) and/or (30c) as an auxiliary resin is fed, at a proper timing, from the cylindrical flow passage (4) and the center flow passage (36) on the inside into the molten resin (30a) on the outside by controlling the opening/closing valve (7) or the center opening/closing valve (39).
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: April 17, 2012
    Assignee: Toyo Seikan Kaisha, Ltd.
    Inventors: Hotaka Fukabori, Tsuneo Imatani, Makoto Etoh, Kazunobu Watanabe
  • Publication number: 20090096129
    Abstract: A method of feeding a composite molten resin capable of easily forming a multi-kind-multi-layer preform. An apparatus for feeding the composite molten resin has a nozzle portion which includes an outer discharge port in which an outermost annular flow path through which a main layer-forming molten resin flows, meets an outer annular flow path through which a sub-layer-forming molten resin flows inside of the outermost annular flow path; and an inner discharge port in which a shell layer-forming molten resin annularly flowing inside of the outer conflux path, meets the core layer-forming molten resin flowing inside the shell layer; the outer discharge port and the inner discharge port being arranged in this order from the downstream toward the upstream in a direction in which the molten resins flow; wherein provision is made of a shaft-like opening/closing valve for opening and closing the inner discharge port, and a gear pump for intermittently discharging the sub-layer-forming molten resin.
    Type: Application
    Filed: March 15, 2007
    Publication date: April 16, 2009
    Inventors: Norihisa Hirota, Kazunobu Watanabe, Yutaka Asano, Jotaro Nagao
  • Publication number: 20090074898
    Abstract: An extrusion feed device for a composite resin capable of forming a composite resin extruded material having a variety of layer configurations not necessarily symmetrical. A plurality of cylindrical flow passages (3) and (4) for feeding a molten resin, an opening/closing valve (7) capable of opening/closing a center flow passage (36) and a cylindrical flow passage (4a), and a center opening/closing valve (39) capable of opening/closing the center flow passage are provided at the upstream side end part (2a) of a discharge passage (2) for delivering the composite resin extruded material. A main resin (30a) forming an outside layer is always fed from the cylindrical flow passage (3), and the other molten resin (30b) and/or (30c) as an auxiliary resin is fed, at a proper timing, from the cylindrical flow passage (4) and the center flow passage (36) on the inside into the molten resin (30a) on the outside by controlling the opening/closing valve (7) or the center opening/closing valve (39).
    Type: Application
    Filed: January 12, 2005
    Publication date: March 19, 2009
    Applicant: TOYO SEIKAN KAISHA, LTD.
    Inventors: Hotaka Fukabori, Tsuneo Imatani, Makoto Etoh, Kazunobu Watanabe
  • Publication number: 20090014915
    Abstract: A method of feeding a molten resin mass, which is capable of causing a molten resin mass to fall down into a female mold for compression molding without delay in the timing from a cylindrical transfer guide that cuts a portion of a molten resin extruded from a die head of an extruder and transfers it to a female mold for compression forming, and an apparatus therefor. The apparatus for feeding the molten resin mass has a cylindrical transfer guide which transfers a molten resin mass obtained by cutting a predetermined amount of a molten resin extruded from a die head of an extruder to a female mold for compression molding, wherein the transfer guide is provided with vibration-generating means for imparting vibration to the transfer guide. In the method of feeding the molten resin mass, the pressure in the cylindrical transfer guide is set to be higher than the pressure in the female mold for compression molding.
    Type: Application
    Filed: February 16, 2007
    Publication date: January 15, 2009
    Applicant: TOYO SEIKAN KAISHA, LTD.
    Inventors: Yutaka Asano, Norihisa Hirota, Jotaro Nagao, Kazunobu Watanabe
  • Patent number: 7341684
    Abstract: A composite synthetic resin material forming apparatus comprises an outer channel having an outer outlet, an inner channel having an inner outlet opening into the outer channel, outer synthetic resin supply means for flowing an outer synthetic resin through the outer channel, and inner synthetic resin supply means for flowing an inner synthetic resin through the inner channel. Opening and closing means for selectively opening and closing the inner outlet is disposed. The outer synthetic resin supply means intermittently supplies the outer synthetic resin to the outer channel in accordance with opening and closing of the inner outlet by the opening and closing means.
    Type: Grant
    Filed: January 22, 2004
    Date of Patent: March 11, 2008
    Assignee: Toyo Seikan Kaisha, Ltd.
    Inventors: Tsuneo Imatani, Makoto Etoh, Kazunobu Watanabe, Hotaka Fukabori, Ikuo Komatsu
  • Publication number: 20070122578
    Abstract: It is an object of the invention to obtain a multilayered molten resin mass capable of providing a multilayered compression-molded product in which the layers of the multilayered compression-molded product are distributed uniformly in the circumferential direction with the intermediate resin layer positioned entirely within the inner and outer resin layers.
    Type: Application
    Filed: October 20, 2004
    Publication date: May 31, 2007
    Applicant: TOYO SEIKAN KAISHA, LTD.
    Inventors: Kazunobu Watanabe, Makoto Etoh, Hotaka Fukabori, Norihisa Hirota, Satoshi Shibata, Tsuneo Imatani
  • Publication number: 20060051444
    Abstract: A composite synthetic resin material forming apparatus comprises an outer channel having an outer outlet, an inner channel having an inner outlet opening into the outer channel, outer synthetic resin supply means for flowing an outer synthetic resin through the outer channel, and inner synthetic resin supply means for flowing an inner synthetic resin through the inner channel. Opening and closing means for selectively opening and closing the inner outlet is disposed. The outer synthetic resin supply means intermittently supplies the outer synthetic resin to the outer channel in accordance with opening and closing of the inner outlet by the opening and closing means.
    Type: Application
    Filed: January 22, 2004
    Publication date: March 9, 2006
    Inventors: Tsuneo Imatani, Makoto Etoh, Kazunobu Watanabe, Hotaka Fukabori, Ikuo Komatsu
  • Patent number: 6929836
    Abstract: A multi-layered perform for substantially preventing the generation of strains and obtaining improved stress cracking resistance with excellent appearance characteristics includes a mouth portion, a body portion and a bottom portion and has at least the body portion and the bottom portion formed of an inner layer, an intermediate layer, and an outer layer by a compression molding. A multi-layered bottle is manufactured by performing a biaxial stretch blow molding of such multi-layered perform. The multi-layered bottle includes a mouth portion a shoulder portion, a body portion and a bottom portion. At least the shoulder portion, the body portion and the bottom portion include an inner layer, an intermediate layer and an outer layer.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: August 16, 2005
    Assignee: Toyo Seikan Kaisha, Ltd.
    Inventors: Atsushi Kikuchi, Yorihisa Hamada, Makoto Etoh, Kazunobu Watanabe
  • Publication number: 20040091652
    Abstract: A multi-layered perform for substantially preventing the generation of strains and obtaining improved stress cracking resistance with excellent appearance characteristics includes a mouth portion, a body portion and a bottom portion and has at least the body portion and the bottom portion formed of an inner layer, an intermediate layer, and an outer layer by a compression molding. A multi-layered bottle is manufactured by performing a biaxial stretch blow molding of such multi-layered perform. The multi-layered bottle includes a mouth portion a shoulder portion, a body portion and a bottom portion. At least the shoulder portion, the body portion and the bottom portion include an inner layer, an intermediate layer and an outer layer.
    Type: Application
    Filed: October 31, 2003
    Publication date: May 13, 2004
    Applicant: TOYO SEIKAN KAISHA, LTD.
    Inventors: Atsushi Kikuchi, Yorihisa Hamada, Makoto Etoh, Kazunobu Watanabe
  • Publication number: 20020098310
    Abstract: A multi-layered preform for substantially preventing the generation of strains and obtaining improved stress cracking resistance with excellent appearance characteristics includes a mouth portion, a body portion and a bottom portion and has at least the body portion and the bottom portion formed of an inner layer, an intermediate layer, and an outer layer by a compression molding. A multi-layered bottle is manufactured by performing a biaxial stretch blow molding of such multi-layered perform. The multi-layered bottle includes a mouth portion, a shoulder portion, a body portion and a bottom portion. At least the shoulder portion, the body portion and the bottom portion include an inner layer, an intermediate layer and an outer layer.
    Type: Application
    Filed: October 1, 2001
    Publication date: July 25, 2002
    Applicant: TOYO SEIKAN KAISHA LTD.
    Inventors: Atsushi Kikuchi, Yorihisa Hamada, Makoto Etoh, Kazunobu Watanabe