Patents by Inventor Yutaka Hirai

Yutaka Hirai 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: 4369372
    Abstract: This invention provides a photo electro transducer device having a photo electro transducer unit in which plural photo electro transducer elements having light receiving faces are arranged in an array, and a crosstalk preventing unit composed of diode elements respectively connected electrically to these photo electro transducer elements.
    Type: Grant
    Filed: June 17, 1980
    Date of Patent: January 18, 1983
    Assignee: Canon Kabushiki Kaisha
    Inventors: Seishiro Yoshioka, Yutaka Hirai, Tadaji Fukuda, Masaki Fukaya, Takashi Nakagiri
  • Patent number: 4299766
    Abstract: Lactam-blocked products of alicyclic isocyanates are obtained by blocking an aromatic isocyanate with lactam and subjecting the resulting blocked product to catalytic hydrogenation with use of a Rh catalyst.The blocked alicyclic isocyanate obtained thus can be used, for example, as a curing agent for synthetic resins such as epoxy resins or as a starting material of urethane coatings.The blocked isocyanate, if desired, may be subject to distillation whereby an alicyclic isocyanate is isolated by thermal dissociation and separation of the blocking agent.
    Type: Grant
    Filed: July 21, 1980
    Date of Patent: November 10, 1981
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Ryuichi Yamamoto, Yutaka Hirai, Akinobu Takagi, Zyunzi Tashima
  • Patent number: 4265991
    Abstract: A layer of amorphous silicon containing H, preferably 10-40 atomic %H, is used as a photoconductive layer for electrophotographic photosensitive member.
    Type: Grant
    Filed: December 19, 1978
    Date of Patent: May 5, 1981
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yutaka Hirai, Toshiyuki Komatsu, Katsumi Nakagawa, Teruo Misumi, Tadaji Fukuda
  • Patent number: 4186269
    Abstract: An aromatic urethane is obtained at high yield without involving corrosion of a stainless steel reactor by interacting an aromatic nitro compound, an organic compound having at least one hydroxyl group therein and carbon monoxide in the presence of a catalyst composed of (1) palladium, ruthenium, rhodium or compounds thereof, (2) a Lewis acid, and (3) a tertiary amine. For instance, 2,4-dinitrotoluene, ethanol and carbon monoxide placed in a SUS-32 reactor are interacted in the presence of a catalyst composed of (1) 5% palladium on carbon, (2) ferric chloride, and (3) pyridine to obtain 2,4-diethyldicarbamatetoluene without corrosion of the reactor. After completion of the reaction, the catalyst and reaction product are separated from the reaction system; e.g., the insoluble catalyst is first separated and then the reaction solution is cooled down, e.g., to room temperature, to separate the reaction product as crystals, followed by separation of the crystals by filtration.
    Type: Grant
    Filed: December 31, 1975
    Date of Patent: January 29, 1980
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Yutaka Hirai, Katsuharu Miyate, Makoto Aiga
  • Patent number: 4178455
    Abstract: In a process for preparing an aromatic urethane which comprises reacting an aromatic nitro compound, an organic compound containing at least one hydroxyl group, and carbon monoxide at elevated temperature and pressure in the presence of a catalytic system composed of a catalyst consisting of a platinum metal, a platinum metal compound, and/or a platinum metal compound-containing compound and a promoter consisting of a Lewis acid and/or a Lewis acid-containing compound, an organic primary amino compound, a urea compound, a biuret compound, an allophanate compound, or a mixture thereof is added to the reaction system whereby the reaction rate is increased and the yield of the desired product is enhanced. For example, 2,4-diethylcarbamatetoluene can be prepared in quantitatively high yield by reacting 2,4-dinitrotoluene, ethanol, carbon monoxide, and a small amount of aminonitrotoluene at elevated temperature and pressure in the presence of palladium chloride and ferrous chloride-pyridine complex.
    Type: Grant
    Filed: July 17, 1978
    Date of Patent: December 11, 1979
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Yutaka Hirai, Katsuharu Miyata, Makoto Aiga, Seiji Hasegawa
  • Patent number: 4170708
    Abstract: Aromatic urethanes are produced by interacting an aromatic nitro compound, an organic compound containing hydroxyl groups and carbon monoxide in the presence of a catalyst composed of elemental selenium or a selenium compound and of a promoter composed of a bicyclic amidine together with a phenolic compound or a carboxylic acid. The interaction proceeds smoothly with the aid of a small amount of the promoter, attended with secondary production of amino compounds only in small amounts. For instance, 2,4-diethyldicarbamatetoluene is obtained at a yield of 87% by interacting 2,4-dinitrotoluene, ethanol and carbon monoxide in the presence of a catalytic system composed of metallic selenium, 1,8-diazabicyclo(5,4,0)-undecene-7 and acetic acid.
    Type: Grant
    Filed: March 8, 1976
    Date of Patent: October 9, 1979
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Yutaka Hirai, Katsuharu Miyata, Seiji Hasegawa
  • Patent number: 4139562
    Abstract: A process for purifying crude p-aminophenol which contains 4,4'-diaminodiphenyl ether and other impurities, which process comprising adding an alkali metal compound to the crude p-aminophenol in an aqueous medium in an atmosphere of an inert gas and, if necessary, in the presence of a reducing agent to give an aqueous solution of an alkali metal salt of p-aminophenol, and contacting the aqueous solution with an inert organic solvent immiscible with water to permit 4,4'-diaminodiphenyl ether and other impurities to be separated by extraction in the solvent.
    Type: Grant
    Filed: March 13, 1978
    Date of Patent: February 13, 1979
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Ryuichi Yamamoto, Yutaka Hirai, Teruyuki Nagata
  • Patent number: 4134880
    Abstract: An aromatic urethane of high quality and excellent heat stability can be produced in high yield by reacting an aromatic nitro compound, a hydroxyl group-containing organic compound and carbon monoxide in the presence of a catalytic system composed of (1) palladium, ruthenium, rhodium or a compound thereof, (2) a Lewis acid, and (3) ammonia. The use of such catalytic system can suppress undesirable side reactions to a satisfactory extent and ensures the reaction to proceed without causing any corrosion of a stainless steel reactor. If necessary, water may be added to the reaction system to increase the reaction velocity, by which the unit cost of the catalyst can be reduced.
    Type: Grant
    Filed: January 19, 1978
    Date of Patent: January 16, 1979
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Katsuharu Miyata, Yutaka Hirai, Hiroshi Yoshida
  • Patent number: 4080365
    Abstract: Aromatic urethanes can be produced in exceedingly improved yield when an aromatic nitro compound, an organic compound containing hydroxyl groups, and carbon monoxide are reacted in the presence of a catalyst composed of metallic (elemental) selenium or a selenium compound and a base serving as promoter, to which reaction system an aromatic amino compound and/or an aromatic urea compound which will be secondarily produced by the reaction has been previously added in order to suppress side reactions. For instance, when nitrobenzene, methanol and carbon monoxide are interacted in the presence of metallic selenium and triethylenediamine, the conversion of nitrobenzene is 68% and the percentage of formed methyl N-phenylcarbamate to the interacted nitrobenzene is 80%, whereas when the reaction is effected under the same reaction conditions indicated above with addition to the reaction system of aniline in an amount of about 15 wt.
    Type: Grant
    Filed: May 19, 1976
    Date of Patent: March 21, 1978
    Assignee: Mitsui Toatsu Chemicals
    Inventors: Yutaka Hirai, Katsuharu Miyata, Seiji Hasegawa
  • Patent number: 4070401
    Abstract: A method for the preparation of a halogenated aromatic amine, wherein a halogenated aromatic nitro compound is hydrogenated in liquid phase in the presence of a platinum-base catalyst to obtain a corresponding halogenated aromatic amine, the hydrogenation being carried out in the presence of an alkylmonoamine, an alicyclic amine or a polyalkylenepolyamine. The presence of the amine well suppresses a dehalogenation reaction which would otherwise be involved, so that not only a high purity halogenated aromatic amine is obtained, but also corrosion of a reactor is prevented.
    Type: Grant
    Filed: February 12, 1973
    Date of Patent: January 24, 1978
    Assignee: Mitsui Toatsu Chemicals Inc.
    Inventors: Yutaka Hirai, Katsuharu Miyata
  • Patent number: 4054586
    Abstract: A process for preparing 1-aminoanthraquinone having high purity, which comprises either1. hydrogenating 1-nitroanthraquinone in an aqueous medium in the presence of a base using a hydrogenating catalyst, and then oxidizing the hydrogenation product, or2. hydrogenating crude 1-nitroanthraquinone containing dinitroanthraquinones as impurities or crude 1-aminoanthraquinone containing diaminoanthraquinones as impurities in an aqueous medium in the presence of a base using a hydrogenating catalyst, stopping the hydrogenation at a time when the 1-nitroanthraquinone or 1-aminoanthraquinone has been substantially reduced to 1-aminoanthrahydroquinone but the dinitroanthraquinones or diaminoanthraquinones remain substantially unreduced to diaminoanthrahydroquinones, removing water-insoluble materials from the reaction mixture, and then oxidizing the remaining water-soluble residue.
    Type: Grant
    Filed: December 16, 1975
    Date of Patent: October 18, 1977
    Assignee: Mitsui Toatsu Chemicals Incorporated
    Inventors: Yutaka Hirai, Katsuharu Miyata, Tagui Osawa
  • Patent number: 4046785
    Abstract: A process for preparing aminoanthraquinones of high purity, which comprises catalytically hydrogenating nitroanthraquinones in the suspended state in an aqueous medium in the presence of a hydrogenating catalyst. In a preferred embodiment, the catalytic hydrogenation may be carried out in the presence of an organic or inorganic base, followed, if desired, by oxidizing the hydrogenation product.
    Type: Grant
    Filed: December 18, 1975
    Date of Patent: September 6, 1977
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Yutaka Hirai, Katsuharu Miyata, Tagui Osawa, Muneyasu Samecima, Ken Mukai, Koichi Yoshiura, Hidetoshi Mori