Patents by Inventor Mikio Nakazawa

Mikio Nakazawa 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: 6187968
    Abstract: This invention provides a process for preparing cyclohexanedimethanol comprising hydrogenating a cyclohexanedicarboxylic acid dialkyl ester by a fixed-bed continuous reaction in the presence of a preformed copper-containing catalyst under the conditions of reaction temperature of 200 to 280° C., hydrogen pressure of 185 to 300 kgf/cm2 and hydrogen gas feed rate of 1 to 40 cm/s in terms of superficial linear velocity, the cyclohexanedicarboxylic acid dialkyl ester being prepared, typically, by ring hydrogenating of an aromatic dicarboxylic acid dialkyl ester in the presence of a preformed supported ruthenium catalyst by a fixed-bed continuous reaction.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: February 13, 2001
    Assignee: SK NJC Co., Ltd.
    Inventors: Hiroshi Itoh, Yasuhisa Yoshida, Taiichiro Iwamura, Mikio Nakazawa
  • Patent number: 5504128
    Abstract: This invention provides a thermoplastic resin composition comprising a thermoplastic resin and 0.1 to 100 parts by weight, per 100 parts by weight of the thermoplastic resin, of an imide compound prepared, e.g., by dehydration condensation of 1,2,3,4-butanetetracarboxylic acid or a monoanhydride or a dianhydride thereof with a primary amine, and a method of molding the resin composition.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: April 2, 1996
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Toshihiro Mizutani, Kango Fujitani, Mikio Nakazawa
  • Patent number: 5091564
    Abstract: Disclosed is a process for preparing a diphenyl sulfonetetracarboxylic acid, the process comprising oxidizing a tetramethyldiphenyl sulfone with oxygen or an oxygen-containing gas in an aliphatic monocarboxylic acid having 2 to 10 carbon atoms in the presence of a catalyst consisting essentially of a cobalt component, a manganese component and a bromine compound wherein the weight ratio of manganese metal to cobalt metal is in the range of approximately 0.01 to 0.5.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: February 25, 1992
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Hiroshi Manami, Mikio Nakazawa, Shigeo Miki, Akihiro Nishiuchi
  • Patent number: 4914231
    Abstract: Disclosed is a method for purifying a crude diphenylsulfone tetracarboxylic acid which comprises the steps of dissolving a crude diphenyolsulfone tetracarboxylic acid in a solvent mixture of water and acetic acid and recrystallizing the crude to obtain a highly purifed diphenylsulfone tetracarboxylic acid.
    Type: Grant
    Filed: September 16, 1988
    Date of Patent: April 3, 1990
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Hiroshi Manami, Shigeo Miki, Mikio Nakazawa
  • Patent number: 4833272
    Abstract: Disclosed is a process for preparing a polycarboxylic acid, the process comprising subjecting a Diels-Alder reaction product of maleic anhydride and a diene and/or the corresponding acid to oxidative cleavage using hydrogen peroxide in the presence of at least one catalyst selected from the group consisting of tungstic acid, molybdic acid and heteropoly acids thereof.
    Type: Grant
    Filed: April 7, 1986
    Date of Patent: May 23, 1989
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Mikio Nakazawa, Kango Fujitani
  • Patent number: 4778932
    Abstract: In preparing a diarylsulfone by condensing sulfuric acid or an aromatic sulfonic acid with an aromatic compound having at least one replaceable hydrogen atom on the aromatic ring, the process of the present invention is characterized in that the condensation reaction is carried out in the presence of at least one catalyst selected from the group consisting of a tungstic acid, molybdic acid and heteropoly acid thereof.
    Type: Grant
    Filed: July 7, 1987
    Date of Patent: October 18, 1988
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Hiroshi Manami, Shigeo Miki, Mikio Nakazawa
  • Patent number: 4606863
    Abstract: This invention provides a process for preparing carboxylic acid, the process comprising subjecting an oxidation product produced by reacting a peroxide with (a) unsaturated aliphatic monocarboxylic acid having at least one unsaturated bond in the carbon chain and containing 6 to 24 carbon atoms or its ester or (b) cyclic and/or acyclic aliphatic olefin having at least one unsaturated bond in the carbon chain to oxidation by oxygen or oxygen-containing gas in the presence of a catalyst comprising (i) at least one heavy metal compound and (ii) at least one member selected from the group consisting of a bromine compound and a chlorine compound.
    Type: Grant
    Filed: June 1, 1984
    Date of Patent: August 19, 1986
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Mikio Nakazawa, Kango Fujitani, Hiroshi Manami
  • Patent number: 4062893
    Abstract: A process is provided for preparing an N,N-dialkyl aromatic amine by reacting an aromatic amine of the formula ##STR1## wherein R is a hydrogen atom or a lower alkyl group with a lower alcohol in the presence of at least one catalyst selected from sulfuric acid and compounds being capable of forming sulfuric acid during the reaction. The essential features of this process are characterized by:1. maintaining the reaction temperature at 170.degree. to 230.degree. C,2. maintaining the reaction system at a pressure not higher than 10 Kg/cm.sup.2 gauge and capable of keeping the reaction phase liquid, and3. feeding the amine and alcohol starting materials to the reaction system already containing at least one of the amine starting material and N,N-dialkyl aromatic amine, the desired product, and withdrawing the resulting reaction product and unreacted lower alcohol from the system in the form of a vapor while maintaining the above-mentioned pressure.
    Type: Grant
    Filed: March 1, 1976
    Date of Patent: December 13, 1977
    Assignee: New Japan Chemical Company, Limited
    Inventors: Tatsuo Kyuma, Mikio Nakazawa