Patents by Inventor Akihiro Kuwana

Akihiro Kuwana 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).

  • Publication number: 20220002494
    Abstract: Provided is a polyorganosilsesquioxane capable of forming, when cured, a cured product that offers high surface hardness and good heat resistance, is highly flexible, and has excellent processability. The present invention relates to a polyorganosilsesquioxane including a constitutional unit represented by Formula (1). The polyorganosilsesquioxane includes a constitutional unit represented by Formula (I) and a constitutional unit represented by Formula (II) in a mole ratio of the constitutional unit represented by Formula (I) to the constitutional unit represented by Formula (II) of 5 or more. The polyorganosilsesquioxane has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55% to 100% by mole based on the total amount (100% by mole) of all siloxane constitutional units.
    Type: Application
    Filed: August 4, 2021
    Publication date: January 6, 2022
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Nobuhiko HARADA, Maya MASUI, Ichiro TAKASE, Shinji MAETANI, Naoko TSUJI
  • Patent number: 11111337
    Abstract: Provided is a polyorganosilsesquioxane capable of forming, when cured, a cured product that offers high surface hardness and good heat resistance, is highly flexible, and has excellent processability. The present invention relates to a polyorganosilsesquioxane including a constitutional unit represented by Formula (1). The polyorganosilsesquioxane includes a constitutional unit represented by Formula (I) and a constitutional unit represented by Formula (II) in a mole ratio of the constitutional unit represented by Formula (I) to the constitutional unit represented by Formula (II) of 5 or more. The polyorganosilsesquioxane has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55% to 100% by mole based on the total amount (100% by mole) of all siloxane constitutional units.
    Type: Grant
    Filed: June 5, 2018
    Date of Patent: September 7, 2021
    Assignee: DAICEL CORPORATION
    Inventors: Akihiro Kuwana, Nobuhiko Harada, Maya Masui, Ichiro Takase, Shinji Maetani, Naoko Tsuji
  • Publication number: 20210171663
    Abstract: To provide cellulose acetate that exhibits excellent hue even though it is produced by using low grade pulp having a particularly low ?-cellulose content, and also achieves excellent moldability and excellent production efficiency of a molded article. A method for producing cellulose acetate is also provided, the method that can provide cellulose acetate with excellent stable productivity and production efficiency without passing through steps such as extraction. The cellulose acetate of the present invention includes xylose with a molar content rate of greater than 7.0 mol % and not greater than 15 mol % in a sum of molar contents of xylose, mannose, and glucose; and has a hue of not less than 0.60 cm?1 and less than 0.80 cm?1 at a wavelength of 430 nm by absorptiometry; and a 6% viscosity of not greater than 160 mPa┬Ěs.
    Type: Application
    Filed: September 29, 2017
    Publication date: June 10, 2021
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Hiroaki TAMAGAKI
  • Publication number: 20210017296
    Abstract: An object is to provide a cellulose acetate remarkably good in hue even when a low-quality pulp is used. A method for producing the cellulose acetate includes a step (1) of crushing a wood pulp, a step (2) of bringing the crushed wood pulp into contact with acetic acid to subject the pulp to pretreat the wood pulp, a step (3) of causing the wood pulp to react with acetic anhydride after the pretreatment to acetylate the pulp, a step (4) of hydrolyzing the cellulose acetate, which is yielded by the acetylation, and a step (5) of precipitating the cellulose acetate, an acetylation degree of which is adjusted by the hydrolysis. In the hydrolyzing step (4), in a hydrolysis reaction system, a concentration of oxygen is set to 3% or less.
    Type: Application
    Filed: October 1, 2020
    Publication date: January 21, 2021
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Hiroaki TAMAGAKI
  • Patent number: 10364199
    Abstract: A propane production method includes a hydrogenation reaction step of hydrogenation-reacting crude propylene and hydrogen in a presence of a catalyst to obtain gaseous crude propane containing impurities; and an impurity removal step of removing the impurities contained in the gaseous crude propane obtained in the hydrogenation reaction step to obtain purified propane. The impurity removal step includes an adsorptive removal stage of adsorbing and removing water, ethane and propylene contained as impurities in the gaseous crude propane by adsorption treatment in which the gaseous crude propane is brought into contact with an adsorbent, and a separation removal stage of separating and removing hydrogen, oxygen, nitrogen and methane contained as impurities in the crude propane after the adsorption treatment by partial condensation or distillation of crude propane after the adsorption treatment in the adsorptive removal stage.
    Type: Grant
    Filed: January 21, 2016
    Date of Patent: July 30, 2019
    Assignee: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Akihiro Kuwana, Junichi Kawakami, Shuji Tsuno
  • Publication number: 20180282485
    Abstract: Provided is a polyorganosilsesquioxane capable of forming, when cured, a cured product that offers high surface hardness and good heat resistance, is highly flexible, and has excellent processability. The present invention relates to a polyorganosilsesquioxane including a constitutional unit represented by Formula (1). The polyorganosilsesquioxane includes a constitutional unit represented by Formula (I) and a constitutional unit represented by Formula (II) in a mole ratio of the constitutional unit represented by Formula (I) to the constitutional unit represented by Formula (II) of 5 or more. The polyorganosilsesquioxane has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55% to 100% by mole based on the total amount (100% by mole) of all siloxane constitutional units.
    Type: Application
    Filed: June 5, 2018
    Publication date: October 4, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Nobuhiko HARADA, Maya MASUI, Ichiro TAKASE, Shinji MAETANI, Naoko TSUJI
  • Publication number: 20180282434
    Abstract: An object is to provide a cellulose acetate remarkably good in hue even when a low-quality pulp is used. A method for producing the cellulose acetate includes a step (1) of crushing a wood pulp, a step (2) of bringing the crushed wood pulp into contact with acetic acid to subject the pulp to pretreat the wood pulp, a step (3) of causing the wood pulp to react with acetic anhydride after the pretreatment to acetylate the pulp, a step (4) of hydrolyzing the cellulose acetate, which is yielded by the acetylation, and a step (5) of precipitating the cellulose acetate, an acetylation degree of which is adjusted by the hydrolysis. In the hydrolyzing step (4), in a hydrolysis reaction system, a concentration of oxygen is set to 3% or less.
    Type: Application
    Filed: October 5, 2016
    Publication date: October 4, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Hiroaki TAMAGAKI
  • Patent number: 9862656
    Abstract: Provided are a method for producing paraffins and an apparatus for producing paraffins, in which each high-purity paraffin can be produced with high efficiency while complicated operations such as distillation are not carried out. An apparatus for producing paraffins includes a separation and recovery unit and a hydrogenation unit. The separation and recovery unit has a separator containing silver ions, and separates impurities from raw material olefins containing olefins as main components and recovers the olefins, by bringing the raw material olefins into contact with the separator. The hydrogenation unit brings the olefins recovered by the separation and recovery unit into contact with hydrogen in a presence of a catalyst and subjects the recovered olefins to a hydrogenation reaction, thereby obtaining high-purity paraffins.
    Type: Grant
    Filed: September 25, 2012
    Date of Patent: January 9, 2018
    Assignee: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Akihiro Kuwana, Jun-ichi Sakamoto, Hiroyuki Hata
  • Publication number: 20170349506
    Abstract: A propane production method includes a hydrogenation reaction step of hydrogenation-reacting crude propylene and hydrogen in a presence of a catalyst to obtain gaseous crude propane containing impurities; and an impurity removal step of removing the impurities contained in the gaseous crude propane obtained in the hydrogenation reaction step to obtain purified propane. The impurity removal step includes an adsorptive removal stage of adsorbing and removing water, ethane and propylene contained as impurities in the gaseous crude propane by adsorption treatment in which the gaseous crude propane is brought into contact with an adsorbent, and a separation removal stage of separating and removing hydrogen, oxygen, nitrogen and methane contained as impurities in the crude propane after the adsorption treatment by partial condensation or distillation of crude propane after the adsorption treatment in the adsorptive removal stage.
    Type: Application
    Filed: January 21, 2016
    Publication date: December 7, 2017
    Applicant: SUMITOMO SEIKA CHEMICALS CO., LTD.
    Inventors: Akihiro KUWANA, Junichi KAWAKAMI, Shuji TSUNO
  • Publication number: 20160297933
    Abstract: Provided is a polyorganosilsesquioxane capable of forming, when cured, a cured product that offers high surface hardness and good heat resistance, is highly flexible, and has excellent processability. The present invention relates to a polyorganosilsesquioxane including a constitutional unit represented by Formula (1). The polyorganosilsesquioxane includes a constitutional unit represented by Formula (I) and a constitutional unit represented by Formula (II) in a mole ratio of the constitutional unit represented by Formula (I) to the constitutional unit represented by Formula (II) of 5 or more. The polyorganosilsesquioxane has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55% to 100% by mole based on the total amount (100% by mole) of all siloxane constitutional units.
    Type: Application
    Filed: November 14, 2014
    Publication date: October 13, 2016
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Nobuhiko HARADA, Maya MASUI, Ichiro TAKASE, Shinji MAETANI, Naoko TSUJI
  • Patent number: 9447277
    Abstract: Provided is a curable resin composition capable of forming a cured product that excels in heat resistance, transparency, and flexibility and particularly excels in barrier properties against a corrosive gas (e.g., sulfur oxide). The curable resin composition includes a compound (U) containing an aliphatic carbon-carbon unsaturated bond and a compound (H) containing a hydrosilyl group and includes at least one of a ladder-type silsesquioxane [A1] and a ladder-type silsesquioxane [A2], where the ladder-type silsesquioxane [A1] contains an aliphatic carbon-carbon unsaturated bond and has a number-average molecular weight of 500-1500 and a molecular weight dispersity (Mw/Mn) of 1.00-1.40 as determined by gel permeation chromatography and calibrated with a polystyrene standard, and the ladder-type silsesquioxane [A2] contains a hydrosilyl group and has a number-average molecular weight of 500-1500 and a molecular weight dispersity (Mw/Mn) of 1.00-1.
    Type: Grant
    Filed: May 17, 2013
    Date of Patent: September 20, 2016
    Assignee: DAICEL CORPORATION
    Inventors: Shigeaki Kamuro, Akihiro Kuwana, Nobuhiko Harada
  • Publication number: 20150126700
    Abstract: Provided is a curable resin composition capable of forming a cured product that excels in heat resistance, transparency, and flexibility and particularly excels in barrier properties against a corrosive gas (e.g., sulfur oxide). The curable resin composition includes a compound (U) containing an aliphatic carbon-carbon unsaturated bond and a compound (H) containing a hydrosilyl group and includes at least one of a ladder-type silsesquioxane [A1] and a ladder-type silsesquioxane [A2], where the ladder-type silsesquioxane [A1] contains an aliphatic carbon-carbon unsaturated bond and has a number-average molecular weight of 500-1500 and a molecular weight dispersity (Mw/Mn) of 1.00-1.40 as determined by gel permeation chromatography and calibrated with a polystyrene standard, and the ladder-type silsesquioxane [A2] contains a hydrosilyl group and has a number-average molecular weight of 500-1500 and a molecular weight dispersity (Mw/Mn) of 1.00-1.
    Type: Application
    Filed: May 17, 2013
    Publication date: May 7, 2015
    Applicant: DAICEL CORPORATION
    Inventors: Shigeaki Kamuro, Akihiro Kuwana, Nobuhiko Harada
  • Publication number: 20140378721
    Abstract: Provided are a method for producing paraffins and an apparatus for producing paraffins, in which each high-purity paraffin can be produced with high efficiency while complicated operations such as distillation are not carried out. An apparatus for producing paraffins includes a separation and recovery unit and a hydrogenation unit. The separation and recovery unit has a separator containing silver ions, and separates impurities from raw material olefins containing olefins as main components and recovers the olefins, by bringing the raw material olefins into contact with the separator. The hydrogenation unit brings the olefins recovered by the separation and recovery unit into contact with hydrogen in a presence of a catalyst and subjects the recovered olefins to a hydrogenation reaction, thereby obtaining high-purity paraffins.
    Type: Application
    Filed: September 25, 2012
    Publication date: December 25, 2014
    Inventors: Akihiro Kuwana, Jun-ichi Sakamoto, Hiroyuki Hata
  • Patent number: 7285684
    Abstract: A reaction mixture obtained by reacting a substrate in the presence of an imide compound having an imide unit represented by the formula (1) can be efficiently separated through crystallization and/or extraction with a specific solvent into the imide compound and a reaction product. (In the formula, X represents oxygen, hydroxyl, or acyloxy.) Furthermore, a mixture comprising the imide compound and a metal catalyst can be efficiently separated through crystallization, adsorption, and/or extraction into the imide compound and the metal catalyst.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: October 23, 2007
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Hiroyuki Miura, Hitoshi Watanabe, Akihiro Kuwana, Mami Shimamura, Naruhisa Hirai
  • Publication number: 20020169331
    Abstract: A reaction product and an imide compound can be separated from a reaction mixture obtained by reacting a substrate in the presence of the imide compound having an imide unit represented by the following formula (1): 1
    Type: Application
    Filed: December 4, 2001
    Publication date: November 14, 2002
    Inventors: Hiroyuki Miura, Hitoshi Watanabe, Akihiro Kuwana, Mami Shimamura, Naruhisa Hirai
  • Patent number: 5446176
    Abstract: Disclosed are the improvements of a process for the preparation of a purified 3,4-epoxycyclohexyl methyl (meth)acrylate and 3,4-epoxycyclohexyl methyl (meth)acrylate which is prepared by the improvements, including only minor amounts of polymers having a low molecular weight composed of 3,4-epoxycyclohexyl methyl (meth)acrylate itself.Furthermore, disclosed is a 3,4-epoxycyclohexyl methyl (meth)acrylate composition which has an excellent resistance to coloring, including a specified organic phosphorous compound.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: August 29, 1995
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Akihiro Kuwana, Kimihide Honda, Kunio Koga
  • Patent number: 5426193
    Abstract: Disclosed are the improvements of a process for the preparation of a purified 3,4-epoxycyclohexyl methyl (meth)acrylate and 3,4-epoxycyclohexyl methyl (meth)acrylate which is prepared by the improvements, including only minor amounts of polymers having a low molecular weight composed of 3,4-epoxycyclohexyl methyl (meth)acrylate itself.Furthermore, disclosed is a 3,4-epoxycyclohexyl methyl (meth)acrylate composition which has an excellent resistance to coloring, including a specified organic phosphorous compound.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: June 20, 1995
    Assignee: Daicel Chemical Industries, Inc.
    Inventors: Akihiro Kuwana, Kimihide Honda, Kunio Koga
  • Patent number: 5382676
    Abstract: Disclosed are the improvements of a process for the preparation of a purified 3,4-epoxycyclohexyl methyl(meth)acrylate and 3,4-epoxyeyclohexyl methyl(meth)acrylate which is prepared by the improvements, including only minor amounts of polymers having a low molecular weight composed of 3,4-epoxycyclohexyl methyl(meth)acrylate itself.Furthermore, disclosed is a 3,4-epoxycyclohexyl methyl(meth)acrylate composition which has an excellent resistance to coloring, including a specified organic phosphorous compound.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: January 17, 1995
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Akihiro Kuwana, Kimihide Honda, Kunio Koga