Patents by Inventor Hideki Yokoyama

Hideki Yokoyama 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: 9102771
    Abstract: A method is disclosed for producing a water-absorbent resin by a reversed-phase suspension polymerization method, wherein an odor originating from a raw material component, in particular, a petroleum hydrocarbon dispersion medium, is further reduced as compared with a water-absorbent resin obtained by a conventional method, and a water-absorbent resin obtained by the method. More specifically, a method is disclosed for producing a water-absorbent resin by performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium, comprising adding and dispersing an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent to a petroleum hydrocarbon dispersion medium in the presence of a surfactant under stirring, and performing a reversed-phase suspension polymerization using a radical polymerization initiator, and a water-absorbent resin obtained by the method.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: August 11, 2015
    Assignee: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Hideki Yokoyama, Atsushi Heguri, Nobuhiro Maeda
  • Patent number: 9074022
    Abstract: A purpose of the present invention is to reduce odor of a water-absorbent resin during absorption of water. Such the invention is attained by a process for production of a water-absorbent resin by subjecting a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization. The process comprises the following steps (A) to (C): (A) adding an aqueous solution of water-soluble ethylenically unsaturated monomer to a petroleum hydrocarbon dispersion medium to disperse the aqueous solution in the dispersion medium; (B) adding a surfactant to the emulsion to further disperse the emulsion; and (C) performing the reversed-phase suspension polymerization using a water-soluble radical polymerization initiator, optionally in the presence of an internal-crosslinking agent.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: July 7, 2015
    Assignee: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Hideki Yokoyama, Yasuhiro Nawata
  • Patent number: 8883944
    Abstract: A method for producing a water-absorbent resin by performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium, comprising the following steps of: (A) performing a primary dispersion in the absence of surfactants by adding an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent to a petroleum hydrocarbon dispersion medium in which a hydrophobic polymeric dispersion agent was heat-dispersed or heat-dissolved, under stirring; (B) further performing a secondary dispersion by adding a surfactant to a dispersion liquid obtained after the primary dispersion; and (C) performing the reversed-phase suspension polymerization by using a radical polymerization initiator; and the water-absorbent resin obtained by the method.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: November 11, 2014
    Assignee: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Atsushi Heguri, Sachi Kikuno, Hideki Yokoyama, Nobuhiro Maeda
  • Patent number: 8859700
    Abstract: A method for producing a water-absorbent resin having a further reduced odor as compared with a water-absorbent resin obtained by a conventional method as well as a water-absorbent resin produced by the same method, by maintaining the addition rate V from the pouring nozzle for the aqueous solution of the water-soluble ethylenically unsaturated monomer in a polymerization reaction tank not more than 0.30 [min?1], in the first stage polymerization step which is within the step of the conventional method upon performing multi-stages such as two or more stages of reversed-phase suspension polymerizations in a method for producing a water-absorbent resin, and thereby by being able to reduce the amount of the petroleum hydrocarbon dispersion medium remaining in the above water-absorbent resin.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: October 14, 2014
    Assignee: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Hideki Yokoyama, Sachi Kikuno, Atsushi Heguri, Nobuhiro Maeda
  • Patent number: 8841395
    Abstract: The present invention provides a method for producing a water-absorbent resin by a reversed-phase suspension polymerization method, wherein an odor originating from a raw material component, in particular, a petroleum hydrocarbon dispersion medium, was reduced, and a water-absorbent resin obtained by the method. More specifically, the present invention provides a method for producing a water-absorbent resin comprising performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium by using a surfactant, wherein an aqueous solution of the water-soluble ethylenically unsaturated monomer is dispersed in the dispersion medium at a specific pouring rate to reduce an odor, and a water-absorbent resin obtained by the method, are provided.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: September 23, 2014
    Assignee: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Hideki Yokoyama, Sachi Kikuno, Atsushi Heguri, Nobuhiro Maeda
  • Publication number: 20140179886
    Abstract: A method is disclosed for producing a water-absorbent resin by a reversed-phase suspension polymerization method, wherein an odor originating from a raw material component, in particular, a petroleum hydrocarbon dispersion medium, is further reduced as compared with a water-absorbent resin obtained by a conventional method, and a water-absorbent resin obtained by the method. More specifically, a method is disclosed for producing a water-absorbent resin by performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium, comprising adding and dispersing an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent to a petroleum hydrocarbon dispersion medium in the presence of a surfactant under stirring, and performing a reversed-phase suspension polymerization using a radical polymerization initiator, and a water-absorbent resin obtained by the method.
    Type: Application
    Filed: July 20, 2011
    Publication date: June 26, 2014
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Hideki Yokoyama, Atsushi Heguri, Nobuhiro Maeda
  • Publication number: 20140094570
    Abstract: The present invention provides a water-absorbent resin produced by a reversed-phase suspension polymerization method, which contains a small amount of a petroleum hydrocarbon dispersion medium remaining therein used in reversed-phase suspension polymerization, and thus reducing an odor originating from the petroleum hydrocarbon dispersion medium, when the water-absorbent resin absorbs water, and also which is suitable for use in hygienic materials; an absorbent material and an absorbent article. More particularly, the present invention provides a water-absorbent resin obtained by subjecting an aqueous solution of a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a petroleum hydrocarbon dispersion medium in the presence of a surfactant, wherein the amount of the petroleum hydrocarbon dispersion medium remaining in the water-absorbent resin is 2,000 ppm or less; and an absorbent material and an absorbent article using the same.
    Type: Application
    Filed: December 9, 2013
    Publication date: April 3, 2014
    Applicant: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Hideki Yokoyama, Yasuhiro Nawata
  • Publication number: 20130123454
    Abstract: The present invention provides a method for producing a water-absorbent resin by a reversed-phase suspension polymerization method, wherein an odor originating from a raw material component, in particular, a petroleum hydrocarbon dispersion medium, was reduced, and a water-absorbent resin obtained by the method. More specifically, the present invention provides a method for producing a water-absorbent resin comprising performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium by using a surfactant, wherein an aqueous solution of the water-soluble ethylenically unsaturated monomer is dispersed in the dispersion medium at a specific pouring rate to reduce an odor, and a water-absorbent resin obtained by the method, are provided.
    Type: Application
    Filed: July 20, 2011
    Publication date: May 16, 2013
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Hideki Yokoyama, Sachi Kikuno, Atsushi Heguri, Nobuhiro Maeda
  • Publication number: 20130123455
    Abstract: A method for producing a water-absorbent resin having a further reduced odor as compared with a water-absorbent resin obtained by a conventional method as well as a water-absorbent resin produced by the same method, by maintaining the addition rate V from the pouring nozzle for the aqueous solution of the water-soluble ethylenically unsaturated monomer in a polymerization reaction tank not more than 0.30 [min?1], in the first stage polymerization step which is within the step of the conventional method upon performing multi-stages such as two or more stages of reversed-phase suspension polymerizations in a method for producing a water-absorbent resin, and thereby by being able to reduce the amount of the petroleum hydrocarbon dispersion medium remaining in the above water-absorbent resin.
    Type: Application
    Filed: July 20, 2011
    Publication date: May 16, 2013
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Hideki Yokoyama, Sachi Kikuno, Atsushi Heguri, Nobuhiro Maeda
  • Publication number: 20130119309
    Abstract: A method for producing a water-absorbent resin comprising at least two stages of reversed-phase suspension polymerization, wherein the first stage of the at least two stages of reversed-phase suspension polymerization comprises the following steps of: (A) performing a primary dispersion by stirring to mix in the absence of surfactants an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent with a petroleum hydrocarbon dispersion medium in which a hydrophobic polymeric dispersion agent dissolves or disperses; (B) further performing a secondary dispersion by adding a surfactant to the resultant dispersion liquid; and (C) performing a polymerization by using a water-soluble radical polymerization initiator to obtain a water-absorbent resin as particles in a hydrous gel state which disperse in the petroleum hydrocarbon dispersion medium, and a water-absorbent resin obtained by the method.
    Type: Application
    Filed: July 20, 2011
    Publication date: May 16, 2013
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Sachi Kikuno, Atsushi Heguri, Hideki Yokoyama, Nobuhiro Maeda
  • Publication number: 20130123445
    Abstract: A method for producing a water-absorbent resin by performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium, comprising the following steps of: (A) performing a primary dispersion in the absence of surfactants by adding an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent to a petroleum hydrocarbon dispersion medium in which a hydrophobic polymeric dispersion agent was heat-dispersed or heat-dissolved, under stirring; (B) further performing a secondary dispersion by adding a surfactant to a dispersion liquid obtained after the primary dispersion; and (C) performing the reversed-phase suspension polymerization by using a radical polymerization initiator; and the water-absorbent resin obtained by the method.
    Type: Application
    Filed: July 20, 2011
    Publication date: May 16, 2013
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Atsushi Heguri, Sachi Kikuno, Hideki Yokoyama, Nobuhiro Maeda
  • Publication number: 20100331802
    Abstract: The present invention provides a water-absorbent resin produced by a reversed-phase suspension polymerization method, which contains a small amount of a petroleum hydrocarbon dispersion medium remaining therein used in reversed-phase suspension polymerization, and thus reducing an odor originating from the petroleum hydrocarbon dispersion medium, when the water-absorbent resin absorbs water, and also which is suitable for use in hygienic materials; an absorbent material and an absorbent article. More particularly, the present invention provides a water-absorbent resin obtained by subjecting an aqueous solution of a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a petroleum hydrocarbon dispersion medium in the presence of a surfactant, wherein the amount of the petroleum hydrocarbon dispersion medium remaining in the water-absorbent resin is 2,000 ppm or less; and an absorbent material and an absorbent article using the same.
    Type: Application
    Filed: August 14, 2008
    Publication date: December 30, 2010
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Hideki Yokoyama, Yasuhiro Nawata
  • Publication number: 20100273647
    Abstract: A water-absorbent resin is provided which is suitable for absorbing polymer-containing viscous liquids, wherein the specific surface area measured by the BET multipoint technique using krypton gas as the adsorption gas is no less than 0.05 m2/g, and the water retention capacity for 0.9 wt % physiological saline is 5-30 g/g.
    Type: Application
    Filed: July 8, 2010
    Publication date: October 28, 2010
    Applicant: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Yasuhiro NAWATA, Masakazu YAMAMORI, Koji UEDA, Hideki YOKOYAMA, Masato FUJIKAKE
  • Publication number: 20090182092
    Abstract: A purpose of the present invention is to reduce odor of a water-absorbent resin during absorption of water. Such the invention is attained by a process for production of a water-absorbent resin by subjecting a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization. The process comprises the following steps (A) to (C): (A) adding an aqueous solution of water-soluble ethylenically unsaturated monomer to a petroleum hydrocarbon dispersion medium to disperse the aqueous solution in the dispersion medium; (B) adding a surfactant to the emulsion to further disperse the emulsion; and (C) performing the reversed-phase suspension polymerization using a water-soluble radical polymerization initiator, optionally in the presence of an internal-crosslinking agent.
    Type: Application
    Filed: April 26, 2007
    Publication date: July 16, 2009
    Applicant: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Hideki Yokoyama, Yasuhiro Nawata
  • Publication number: 20090136736
    Abstract: A water-absorbent resin is provided which is suitable for absorbing polymer-containing viscous liquids, wherein the specific surface area measured by the BET multipoint technique using krypton gas as the adsorption gas is no less than 0.05 m2/g, and the water retention capacity for 0.9 wt % physiological saline is 5-30 g/g.
    Type: Application
    Filed: January 15, 2009
    Publication date: May 28, 2009
    Applicant: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: YASUHIRO NAWATA, Masakazu Yamamori, Koji Ueda, Hideki Yokoyama, Masato Fujikake
  • Patent number: 7318868
    Abstract: A ceramic capacitor having a ceramic body and terminal electrodes, the ceramic body being substantially a rectangular parallelopiped in shape, the terminal electrodes being provided at the two ends of the ceramic body in the length direction, each terminal electrode being provided to cover one end face of the ceramic body in the length direction, part of the two surfaces in the width direction, and part of the two surfaces in the thickness direction, wherein, when the length of the ceramic body is L1 and the maximum lengths of the terminal electrodes at the two surfaces of the ceramic body in the width direction are L3 and L4, 0?(|L4?L3|/L1)?0.0227 is satisfied. One surface among the two surfaces of the ceramic body in the width direction is the paste introduction side in the roller coating, while the other surface is the paste escape side in the roller coating.
    Type: Grant
    Filed: August 9, 2006
    Date of Patent: January 15, 2008
    Assignee: TDK Corporation
    Inventors: Hideki Yokoyama, Atsushi Takeda
  • Publication number: 20070178786
    Abstract: A water-absorbent resin is provided which is suitable for absorbing polymer-containing viscous liquids, wherein the specific surface area measured by the BET multipoint technique using krypton gas as the adsorption gas is no less than 0.05 m2/g, and the water retention capacity for 0.9 wt % physiological saline is 5-30 g/g.
    Type: Application
    Filed: March 30, 2007
    Publication date: August 2, 2007
    Applicant: Sumitomo Seika Chemicals Co., Ltd.
    Inventors: Yasuhiro Nawata, Masakazu Yamamori, Koji Ueda, Hideki Yokoyama, Masato Fujikake
  • Publication number: 20070000439
    Abstract: A ceramic capacitor having a ceramic body and terminal electrodes, the ceramic body being substantially a rectangular parallelopiped in shape, the terminal electrodes being provided at the two ends of the ceramic body in the length direction, each terminal electrode being provided to cover one end face of the ceramic body in the length direction, part of the two surfaces in the width direction, and part of the two surfaces in the thickness direction, wherein, when the length of the ceramic body is L1 and the maximum lengths of the terminal electrodes at the two surfaces of the ceramic body in the width direction are L3 and L4, 0?(|L4-L3|/L1)?0.0227 is satisfied. One surface among the two surfaces of the ceramic body in the width direction is the paste introduction side in the roller coating, while the other surface is the paste escape side in the roller coating.
    Type: Application
    Filed: August 9, 2006
    Publication date: January 4, 2007
    Applicant: TDK CORPORATION
    Inventors: Hideki Yokoyama, Atsushi Takeda
  • Patent number: 7115302
    Abstract: A ceramic capacitor having a ceramic body and terminal electrodes, the ceramic body being substantially a rectangular parallelopiped in shape, the terminal electrodes being provided at the two ends of the ceramic body in the length direction, each terminal electrode being provided to cover one end face of the ceramic body in the length direction, part of the two surfaces in the width direction, and part of the two surfaces in the thickness direction, wherein, when the length of the ceramic body is L1 and the maximum lengths of the terminal electrodes at the two surfaces of the ceramic body in the width direction are L3 and L4, 0?|(L4?L3|/L1?0.0227 is satisfied. One surface among the two surfaces of the ceramic body in the width direction is the paste introduction side in the roller coating, while the other surface is the paste escape side in the roller coating.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: October 3, 2006
    Assignee: TDK Corporation
    Inventors: Hideki Yokoyama, Atsushi Takeda
  • Patent number: 6991287
    Abstract: In a vehicle seat system equipped with an active headrest mechanism (30) and a lumbar support (21), a load-receiving part (32) of the active headrest mechanism (30) is positioned behind the lumbar support (21) as viewed from front of the seat. The vehicle seat system is arranged so that when a specified amount or more of load is applied from front of the seat to a lumbar support plate (22) of the lumbar support (21), one end part of a plate support member (23) supporting the lumbar support plate (22) exits from an insertion hole (17) provided at a side frame (4) to disengage from a seatback frame (2), and the disengaged end part of the plate support member (23) then abuts on the load-receiving part (32).
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: January 31, 2006
    Assignees: Toyo Seat Co., Ltd., Mazda Motor Corporation
    Inventors: Kazuharu Ogawa, Hideki Yokoyama, Kouji Matsushita, Kenji Muramatsu, Naoki Kaneko