Patents by Inventor Taku Iwamura

Taku Iwamura 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: 7879923
    Abstract: This invention is to provide a method for surface-treatment of a water absorbent resin excelling in water absorption properties. This invention relates to a method for the surface-treatment of a water absorbent resin, which comprises: a) mixing 100 parts by weight of a water absorbent resin, 0.01-20 parts by weight of at least one radical polymerization initiator selected from the group consisting of persulfates, hydrogen peroxide, and azo compounds, and a radically polymerizing compound and b) irradiating the resultant mixture with active energy rays. The treatment particularly exalts the absorption ratio against pressure and the saline flow conductivity.
    Type: Grant
    Filed: December 9, 2005
    Date of Patent: February 1, 2011
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Makoto Matsumoto, Yoshiro Mitsukami, Hiroyuki Ikeuchi, Kazushi Torii, Taku Iwamura
  • Patent number: 7875362
    Abstract: An absorbent member and a method for making such an absorbent member. The absorbent member includes a modified water absorbent resin having good production efficiency, absorbency against pressure, absorption speed, gel strength, and liquid permeability. The modified water absorbent resin may be made by mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer to obtain a water absorbent resin composition, and irradiating the water absorbent resin composition with active energy rays. During irradiation, the surface water content of the water absorbent resin is at least 3.0 wt %.
    Type: Grant
    Filed: May 20, 2010
    Date of Patent: January 25, 2011
    Assignee: The Procter & Gamble Company
    Inventors: Yoshiro Mitsukami, Makoto Matsumoto, Taku Iwamura
  • Patent number: 7872076
    Abstract: An object of the present invention is to provide a particulate water-absorbent resin composition and its production process, wherein the particulate water-absorbent resin composition is an enhanced one in both of the “liquid permeability” and “liquid-sucking-up property” (which have hitherto been antithetical physical properties) of the water-absorbent resin. As a means of achieving this object, a first particulate water-absorbent resin composition according to the present invention is a particulate water-absorbent resin composition comprising a water-absorbent resin (A) of a crosslinked structure obtained by polymerizing an acid-group-containing unsaturated monomer, with the composition being characterized by: having a particle size such that particles in the range of 850 to 150 ?m (but not including 850 ?m) account for not less than 90 weight % of the entirety; and containing a tetra- or more functional polyol (B) at least on surfaces.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: January 18, 2011
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Hiroyuki Ikeuchi, Kazushi Torii, Taku Iwamura, Sayaka Machida, Hiroko Okochi
  • Publication number: 20100308263
    Abstract: An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850ƒÊm but not less than 106ƒÊm, and logarithmic standard deviation (ƒĐƒÄ) is in a range of 0.25 to 0.
    Type: Application
    Filed: August 13, 2010
    Publication date: December 9, 2010
    Inventors: Kazushi Torii, Hirofumi Shibata, Taku Iwamura, Yoshio Irie, Yorimichi Dairoku, Yoshiro Mitsukami, Sayaka Machida
  • Publication number: 20100298794
    Abstract: An absorbent member and a method for making such an absorbent member. The absorbent member includes a modified water absorbent resin having good production efficiency, absorbency against pressure, absorption speed, gel strength, and liquid permeability. The modified water absorbent resin may be made by mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer to obtain a water absorbent resin composition, and irradiating the water absorbent resin composition with active energy rays. During irradiation, the surface water content of the water absorbent resin is at least 3.0 wt %.
    Type: Application
    Filed: May 20, 2010
    Publication date: November 25, 2010
    Inventors: Yoshiro Mitsukami, Makoto Matsumoto, Taku Iwamura
  • Publication number: 20100261850
    Abstract: Provided is a surface treatment method for a water-absorbent resin having excellent production efficiency, absorption capacity against pressure, fluid permeability or the like. Provided is a method for the surface treatment of a water-absorbent resin which comprises a) a step for mixing 0.1 to 20 parts by weight of an acid group-containing radically polymerizable compound and 5 to 20 parts by weight of water, relative to 100 parts by weight of a water-absorbent resin; and b) a step for polymerizing the acid group-containing radically polymerizable compound, wherein neutralization ratio of the acid group-containing radically polymerizable compound is 0 to 60% by mol, and is lower than neutralization ratio of the water-absorbent resin.
    Type: Application
    Filed: October 8, 2008
    Publication date: October 14, 2010
    Applicant: NIPPON SHOKUBAI CO., LTD.
    Inventors: Yoshiro Mitsukami, Taku Iwamura, Makoto Matsumoto
  • Patent number: 7803880
    Abstract: An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850ƒÊm but not less than 106ƒÊm, and logarithmic standard deviation (ƒĐƒÄ) is in a range of 0.25 to 0.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: September 28, 2010
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazushi Torii, Hirofumi Shibata, Taku Iwamura, Yoshio Irie, Yorimichi Dairoku, Yoshiro Mitsukami, Sayaka Machida
  • Patent number: 7786182
    Abstract: The present invention provides a method for producing a water absorbing agent which excels in water absorption properties. In detail, the present invention provides a method for the production of a water absorbing agent, comprising a) a step of mixing a water absorbing resin, water, and a mixing aid without adding a water-soluble radical polymerization initiator and an ethylenically unsaturated monomer and b) a step of irradiating the resultant mixture with ultraviolet rays while keeping the mixture with flowed state.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: August 31, 2010
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Taku Iwamura, Yoshiro Mitsukami
  • Patent number: 7750085
    Abstract: A water-absorbing agent according to the present invention includes water-absorbent resin particles having an internal cross-linked structure, wherein a vicinity of a surface of the water-absorbent resin particle is cross-linked with a surface cross-linking agent, and the water-absorbent resin particle has therein a sea-island structure having (i) part containing a first water-soluble multivalent metal salt such as aluminum sulfate and (ii) part not containing the first water-soluble multivalent metal salt. With this arrangement, it is possible to provide a water-absorbing agent having less water-soluble component content, more excellent liquid permeability, and more excellent water retention under pressure than the conventional water-absorbing agent.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: July 6, 2010
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazushi Torii, Kenji Kadonaga, Hirofumi Shibata, Taku Iwamura, Kazuki Kimura, Koji Miyake, Kozo Nogi
  • Patent number: 7745507
    Abstract: This invention is to provide an absorbent member and a method for making such an absorbent member. The absorbent member comprises modified water absorbent having good production efficiency, good absorbency against pressure, good absorption speed, gel strength, good liquid permeability, and the like. The modified water absorbent resin is made by a method, which comprises (i) a mixing step comprising mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer, to obtain a water absorbent resin composition, and (ii) an irradiating step comprising irradiating said water absorbent resin composition obtained in the mixing step with active energy rays, wherein the surface water content of said water absorbent resin in said water absorbent resin composition at least at any point of time in the irradiating step (ii) is controlled to a level of not lower than 3.0% by weight based on 100% by weight of the water absorbent resin.
    Type: Grant
    Filed: April 4, 2007
    Date of Patent: June 29, 2010
    Assignee: The Procter & Gamble Company
    Inventors: Yoshiro Mitsukami, Makoto Matsumoto, Taku Iwamura
  • Patent number: 7638570
    Abstract: There is disclosed a water-absorbing agent which combines both performances of the capillary suction force and the liquid permeability. This water-absorbing agent is a particulate water-absorbing agent comprising water-absorbent resin particles (?) and a liquid-permeability-enhancing agent (?), wherein the water-absorbent resin particles (?) are surface-crosslink-treated particles of a crosslinked polymer of a monomer including acrylic acid and/or its salt; with the water-absorbing agent being characterized in that the particulate water-absorbing agent has: a mass-average particle diameter (D50) in the range of 234 to 394 gm, a logarithmic standard deviation (??) of a particle diameter distribution in the range of 0.25 to 0.45, an absorption capacity without load (CRC) of not less than 15 g/g, and a water-extractable component content of not higher than 15 mass %; and further a liquid-permeability-enhancing agent (?) content in the range of 0.
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: December 29, 2009
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazushi Torii, Yoshiro Mitsukami, Motohiro Imura, Taku Iwamura
  • Publication number: 20090298963
    Abstract: This invention is to provide a method for producing a modified water absorbent resin excelling in water absorbing properties. This invention relates to a method for producing a modified water absorbent resin, which comprises a) mixing a water absorbent resin and a water-soluble radical polymerization initiator or a heat-degradable radical polymerization initiator without addition of an ethylenically unsaturated monomer and b) irradiating the resultant mixture with active energy rays. The method is particularly capable of exalting the absorbency against pressure and the saline flow conductivity.
    Type: Application
    Filed: December 9, 2005
    Publication date: December 3, 2009
    Applicant: Nippon Shokubai Co., Ltd
    Inventors: Makoto Matsumoto, Yoshiro Mitsukami, Hiroyuki Ikeuchi, Kazushi Torii, Taku Iwamura, Andreas Flohr, Torsten Lindner
  • Publication number: 20090239966
    Abstract: This invention is to provide a method for surface-treatment of a water absorbent resin excelling in water absorption properties. This invention relates to a method for the surface-treatment of a water absorbent resin, which comprises: a) mixing 100 parts by weight of a water absorbent resin, 0.01-20 parts by weight of at least one radical polymerization initiator selected from the group-consisting of persulfates, hydrogen peroxide, and azo compounds, and a radically polymerizing compound and b) irradiating the resultant mixture with active energy rays. The treatment particularly exalts the absorption ratio against pressure and the saline flow conductivity.
    Type: Application
    Filed: December 9, 2005
    Publication date: September 24, 2009
    Applicant: NIPPON SHOKUBAI CO., LTD.
    Inventors: Makoto Matsumoto, Yoshiro Mitsukami, Hiroyuki Ikeuchi, Kazushi Torii, Taku Iwamura
  • Publication number: 20090234314
    Abstract: In one embodiment of the present invention, a water-absorbent resin composition is provided which shows only small reduction in liquid permeability and limited coloring over time or in relation to another factor. The water-absorbent resin composition (particulate absorbent agent) of the present invention contains: a polycarboxylate-based water-absorbent resin as a primary component, the resin having a crosslinked structure formed by polymerization of an acid group-containing unsaturated monomer; and multivalent metal cations (preferably, on surfaces of particles (i.e., the water-absorbent resin composition)) wherein: the multivalent metal cations other than Fe cations account for 0.001 to 1 mass % of the water-absorbent resin; and the ratio of the Fe cations to the multivalent metal cations other than the Fe cations is less than or equal to 5.00 mass %.
    Type: Application
    Filed: December 19, 2006
    Publication date: September 17, 2009
    Inventors: Masatoshi Nakamura, Koji Miyake, Taku Iwamura, Yusuke Watanabe
  • Publication number: 20090163360
    Abstract: The present invention provides a method for producing a water absorbing agent which excels in water absorption properties. In detail, the present invention provides a method for the production of a water absorbing agent, comprising a) a step of mixing a water absorbing resin, water, and a mixing aid without adding a water-soluble radical polymerization initiator and an ethylenically unsaturated monomer and b) a step of irradiating the resultant mixture with ultraviolet rays while keeping the mixture with flowed state.
    Type: Application
    Filed: September 15, 2006
    Publication date: June 25, 2009
    Applicant: NIPPON SHOKUBAI CO., LTD.
    Inventors: Taku Iwamura, Yoshiro Mitsukami
  • Patent number: 7402643
    Abstract: An object of the present invention is to provide: a water-absorbent resin which can sufficiently overcome the problem of the gel blocking, can manifest sufficient absorption capacity without load and sufficient absorption capacity under load and, at the same time, can also exert excellent liquid permeability under load; and a process for producing the same. As a means of achieving this object, a first production process among the processes according to the present invention for producing a water-absorbent resin having a treated surface is a process comprising: a step of mixing a water-absorbent resin having an internal crosslinked structure obtained by polymerizing a monomer containing acrylic acid and/or a salt thereof as a main component, a complex containing a polyvalent metal atom as a central atom and an organic secondary crosslinking agent in the presence of an aqueous liquid; and a step of crosslinking a surface of the water-absorbent resin with the organic secondary crosslinking agent.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: July 22, 2008
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazushi Torii, Taku Iwamura, Hiroyuki Ikeuchi, Sayaka Machida
  • Publication number: 20080139693
    Abstract: An object of the present invention is to provide a particulate water-absorbent resin composition and its production process, wherein the particulate water-absorbent resin composition is an enhanced one in both of the “liquid permeability” and “liquid-sucking-up property” (which have hitherto been antithetical physical properties) of the water-absorbent resin. As a means of achieving this object, a first particulate water-absorbent resin composition according to the present invention is a particulate water-absorbent resin composition comprising a water-absorbent resin (A) of a crosslinked structure obtained by polymerizing an acid-group-containing unsaturated monomer, with the composition being characterized by: having a particle size such that particles in the range of 850 to 150 ?m (but not including 850 ?m) account for not less than 90 weight % of the entirety; and containing a tetra- or more functional polyol (B) at least on surfaces.
    Type: Application
    Filed: November 5, 2004
    Publication date: June 12, 2008
    Inventors: Hiroyuki Ikeuchi, Kazushi Torii, Taku Iwamura, Sayaka Machida, Hiroko Okochi
  • Publication number: 20070238806
    Abstract: This invention is to provide an absorbent member and a method for making such an absorbent member. The absorbent member comprises modified water absorbent having good production efficiency, good absorbency against pressure, good absorption speed, gel strength, good liquid permeability, and the like. The modified water absorbent resin is made by a method, which comprises (i) a mixing step comprising mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer, to obtain a water absorbent resin composition, and (ii) an irradiating step comprising irradiating said water absorbent resin composition obtained in the mixing step with active energy rays, wherein the surface water content of said water absorbent resin in said water absorbent resin composition at least at any point of time in the irradiating step (ii) is controlled to a level of not lower than 3.0% by weight based on 100% by weight of the water absorbent resin.
    Type: Application
    Filed: April 4, 2007
    Publication date: October 11, 2007
    Inventors: Yoshiro Mitsukami, Makoto Matsumoto, Taku Iwamura
  • Publication number: 20070207924
    Abstract: An object of the present invention is to provide an aqueous-liquid-absorbing agent which comprises water-absorbent resin particles as essential components and is suitable for uses in sanitary materials. As a means of achieving this object, an aqueous-liquid-absorbing agent according to the present invention is an aqueous-liquid-absorbing agent comprising water-absorbent resin particles as essential components, wherein the water-absorbent resin particles are obtained by a process including the step of polymerizing a water-soluble ethylenically unsaturated monomer and have a crosslinked structure in their inside; with the aqueous-liquid-absorbing agent exhibiting an absorption rate (FSR) of not less than 0.2 g/g/s, a water absorption capacity (CRC) of 5 to 25 g/g, a saline flow conductivity (SFC) of not less than 400×10?7 cm3·s/g, and a wet porosity of not less than 20%.
    Type: Application
    Filed: March 11, 2005
    Publication date: September 6, 2007
    Inventors: Hiroyuki Ikeuchi, Kazushi Torii, Shigeru Sakamoto, Taku Iwamura, Sayaka Machida
  • Publication number: 20070167536
    Abstract: The present invention provides an absorbent member for use in absorbent articles, especially for use in diaper or training pants, the absorbent member comprising an absorbing agent which excels in water absorption properties. The absorbing agent is made by a method comprising a) a step of mixing a water absorbing resin, water, and a mixing aid without adding a water-soluble radical polymerization initiator and an ethylenically unsaturated monomer and b) a step of irradiating the resultant mixture with ultraviolet rays while keeping the mixture still agitating the mixture in order to maintain a mixed state.
    Type: Application
    Filed: September 15, 2006
    Publication date: July 19, 2007
    Applicant: The Procter & Gamble Company
    Inventors: Taku Iwamura, Yoshiro Mitsukami