Patents by Inventor Yutaka Konai

Yutaka Konai 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: 5643775
    Abstract: This invention provides highly thermally stable trehalose phosphorylases. The trehalose phosphorylases of the present invention can be obtained from cultured mixture of microorganisms and are highly thermally stable, and produce .alpha.-D-glucose 1-phosphate and D-glucose by an action on trehalose and an inorganic phosphoric acid or salt thereof, or trehalose by an action on .alpha.-D-glucose 1-phosphate and D-glucose. This invention also relates to the process for the preparation of trehalose phosphorylase, and trehalose or .alpha.-D-glucose 1-phosphate with said trehalose phosphorylase.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: July 1, 1997
    Assignee: Kureha Chemical Industry Co., Ltd.
    Inventors: Eisaku Takahashi, Eiichi Takahashi, Kohki Saitoh, Toshihiko Wada, Yutaka Konai
  • Patent number: 5565341
    Abstract: A process for producing trehalose from inexpensive saccharide raw materials via an enzymic method uses stable enzymes with high productivity. The process includes incubating a saccharide raw material and an inorganic phosphoric acid and/or a salt thereof in the presence of phosphorylase to produce .alpha.-glucose 1-phosphate, and contacting the produced .alpha.-glucose 1-phosphate with glucose in the presence of a trehalose phosphorylase to produce trehalose. The isolation and purification of trehalose is easier in comparison to conventional fermentation methods.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: October 15, 1996
    Assignee: Kureha Chemical Industry Co., Ltd.
    Inventors: Eisaku Takahashi, Toshihiko Wada, Yutaka Konai
  • Patent number: 5087742
    Abstract: A process for preparing aromatic polycarboxylic acids is disclosed, wherein a benzil derivative is oxidized with molecular oxygen in the presence of an oxidation catalyst consisting substantially of at least one heavy metal catalyst selected from cobalt and manganese and a bromine catalyst in a solvent containing at least 50 wt.% of an aliphatic monocarboxylic acid having at most three carbon atoms.According to this invention, there are provided 4,4'-bis(4-alkylphenyl)benzils (wherein alkyl is methyl, ethyl or isopropyl), which are novel benzil derivative.
    Type: Grant
    Filed: June 14, 1990
    Date of Patent: February 11, 1992
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Kazuo Yoshida, Nobuyuki Okubo, Toshiharu Matsuda, Yutaka Konai
  • Patent number: 4970338
    Abstract: Biphenyl-4,4'-dicarboxylic acid is prepared by isolating a mixture of diisopropylbiphenyls from a reaction mixture obtained by reacting biphenyl with propylene, crystallizing 4,4'-diisopropylbiphenyl from the mixture of diisopropylbiphenyls, and oxidizing 4,4'-diisopropylbiphenyl or an oxidation intermediate thereof with molecular oxygen in the presence of an oxidation catalyst, which comprises a cobalt catalyst and/or manganese catalyst, in a solvent containing at least 50 wt. % of an aliphatic mono- carboxylic acid having up to 3 carbon atoms.
    Type: Grant
    Filed: November 30, 1988
    Date of Patent: November 13, 1990
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Toshiharu Matsuda, Tadashi Nakamura, Atsushi Sasakawa, Shoichiro Hayashi, Yutaka Konai
  • Patent number: 4960945
    Abstract: The present invention relates to a process for the production of halobenzophenone derivatives represented by the following formula (II): ##STR1## wherein X and Y are the same or different and are independently F, Cl, Br or I, m stands for an integer of from 1 to 4 and n stands for an integer of from 0 to 4. The process comprises oxidizing a compound with an aqueous nitric acid solution having a specific gravity of from 1.32 to 1.47 at 20.degree. C., said compound being represented by the following formula (I): ##STR2## wherein X, Y, m and n have the same meanings as defined above and Z is Cl or H.
    Type: Grant
    Filed: July 13, 1989
    Date of Patent: October 2, 1990
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Takashi Terauchi, Kazuo Yoshida, Yoshihisa Machida, Nobuyuki Okubo, Yutaka Konai
  • Patent number: 4873366
    Abstract: Disclosed in the present invention is a process for producing 2,6-naphthalenedicarboxylic acid comprising oxidizing 2,6-diisopropylnaphthalene or its partially oxidized intermediate with molecular oxygen in a solvent containing at least 50% by weight of an aliphatic monocarboxylic acid, having not more than three carbon atoms, in the presence of a catalyst composed of (i) a heavy metal comprising cobalt and/or manganese and (ii) bromine, and a salt of an inorganic acid having an acid dissociation constant Ka smaller than 1.34.times.10.sup.-5 (at 25.degree. C.) and a vapor pressure lower than that of the aliphatic monocarboxylic acid used as the solvent. According to the process of this invention, 2,6-naphthalenedicarboxylic acid of high bulk density can be obtained in a high yield and with high purity.
    Type: Grant
    Filed: April 5, 1988
    Date of Patent: October 10, 1989
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Toshiharu Matsuda, Atsushi Sasakawa, Shoichiro Hayashi, Yutaka Konai
  • Patent number: 4825007
    Abstract: An aromatic compound selected from benzene and biphenyl compounds containing at least one isopropyl group is oxidized to convert at least one of the at least one isopropyl group into a 2-hydroxy-2-propyl group. The oxidation of the aromatic compound is effected with molecular oxygen in the presence of an aqueous alkali solution in an oxidative reaction vessel made of nickel at parts thereof where the vessel comes into contact with a reaction mixture. In particular, the above process suppresses the formation of by-products and permits long-term oxidation on an industrial scale.
    Type: Grant
    Filed: November 4, 1987
    Date of Patent: April 25, 1989
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Yutaka Konai, Kazuo Yoshida, Masatoshi Hino
  • Patent number: 4814521
    Abstract: Disclosed herein is a process for producing 2,6-dihydroxynaphthalene which comprises oxidizing 2,6-di(2-hydroxy-2-propyl)naphthalene in acetonitrile, 1,4-dioxane or a mixture thereof with hydrogen peroxide in the presence of an inorganic acid or a solid acid at a temperture in the range of room temperature to the boiling point of the solution of the 2,6-di(2-hydroxy-2-propyl)naphthalene in acetonitrile or 1,4-dioxane, the acetonitrile, 1,4-dioxane or a mixture thereof being used in an amount of 3 to 30 ml to one gram of the 2,6-di(2-hydroxy-2-propyl)naphthalene.
    Type: Grant
    Filed: August 26, 1987
    Date of Patent: March 21, 1989
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Takayuki Tanonaka, Takashi Yamauchi, Hiroyuki Enari, Yutaka Konai
  • Patent number: 4804788
    Abstract: 4,4'-Dihydroxybiphenyl is prepared by decomposing 4,4'-di(2-hydroxy-2-propyl)biphenyl with hydrogen peroxide and an acid catalyst in acetonitrile as a solvent. Especially, this process minimizes the formation of byproducts and permits easy purification of the intended product.
    Type: Grant
    Filed: November 4, 1987
    Date of Patent: February 14, 1989
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Yutaka Konai, Tadashi Nakamura, Takayuki Tanonaka, Kazuo Yoshida, Yoshihisa Machida
  • Patent number: 4794195
    Abstract: Disclosed herein is a process for producing a highly pure produce of 2,6-naphthalenedicarboxylic acid in a large quantity at a moderate price by oxidizing 2,6-diisopropylnaphthalene while using a water-soluble salt of cobalt, a water-soluble salt of maganese or a mixture thereof, a water-soluble salt of cerium and a bromine compound as the catalyst of the oxidation.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: December 27, 1988
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Shoichiro Hayashi, Toshiharu Matsuda, Atsushi Sasakawa, Yutaka Konai
  • Patent number: 4668815
    Abstract: Disclosed herein are derivatives of phenylacetic ester represented by the formula (I): ##STR1## wherein R.sup.1 represents a halogen atom or a lower alkoxy group; R.sup.2 represents a lower alkyl group; R.sup.3 represents a hydrogen atom or a methyl group; R.sup.4 represents a hydrogen atom, a lower alkyl group, ##STR2## and R.sup.5 represents a hydrogen atom or a halogen atom, a process for producing the derivatives and an insecticidal composition containing the derivatives of phenylacetic ester as an active ingredient.
    Type: Grant
    Filed: July 2, 1985
    Date of Patent: May 26, 1987
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hiroyuki Enari, Yutaka Konai, Uichi Akiba, Masayo Ito
  • Patent number: 4638087
    Abstract: Disclosed herein are the novel 6-substituted naphthalene-2-carboxylic acids represented by the formula (I): ##STR1## wherein X represents a hydroperoxy group or a hydroxy group, and a process for producing the 6-substituted naphthalene-2-carboxylic acid represented by the formula (I) by reacting 6-isopropylnaphthalene-2-carboxylic acid with molecular oxygen under heating in the presence of a salt of persulfuric acid as a catalyst in an aqueous alkaline solution.
    Type: Grant
    Filed: March 11, 1986
    Date of Patent: January 20, 1987
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Akira Iizuka, Yutaka Konai, Takashi Yamauchi, Shoichiro Hayashi
  • Patent number: 4614620
    Abstract: Disclosed herein is a process for producing i-brassicasterol, comprising charging a mixture of i-sterols derived from a mixture of sterols including brassicasterol into a column packed with a filler obtained by chemically binding alkyl group(s) of 15 to 24 carbon atoms to silica, and subjecting said mixture of i-sterols to reversed-phase partition column-chromatography while using (i) an alcohol of one to three carbon atoms or a mixture therof, or (ii) a mixed solvent comprising more than 50% by volume of said alcohol(s) and a solvent other than said alcohol(s) as an eluent, thereby isolating and purifying i-brassicasterol.
    Type: Grant
    Filed: February 19, 1985
    Date of Patent: September 30, 1986
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yutaka Konai, Shoichiro Hayashi, Yoshikazu Kubota, Kouichi Kodama
  • Patent number: 4607117
    Abstract: Disclosed herein are methyl 2-(2-hydroperoxy-2-propyl)naphthalene-6-carboxylate represented by the formula (I): ##STR1## and a process for producing the compound represented by the formula (I) at a high purity and in a high yield.
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: August 19, 1986
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Akira Iizuka, Yutaka Konai, Takashi Yamauchi, Shoichiro Hayashi
  • Patent number: RE33779
    Abstract: 4,4'-Dihydroxybiphenyl is prepared by decomposing 4,4'-di(2-hydroxy-2-propyl)biphenyl with hydrogen peroxide and an acid catalyst in acetonitrile as a solvent. Especially, this process minimizes the formation of by-products and permits easy purification of the intended product.
    Type: Grant
    Filed: August 13, 1990
    Date of Patent: December 24, 1991
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Yutaka Konai, Tadashi Nakamura, Takayuki Tanonaka, Kazuo Yoshida, Yoshihisa Machida