Patents by Inventor Makoto Takagawa

Makoto Takagawa 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: 6504069
    Abstract: 5-Tolyl-pent-2-ene is cyclized in liquid phase in the present of an aliphatic hydrocarbon to produce the corresponding dimethyltetralin. The use of the aliphatic hydrocarbon effectively prevents a side reaction such as dimerization of 5-tolyl-pent-2-ene to provide dimethyltetralin in a high yield. Also, 5-tolyl-pent-2-ene is cyclized in liquid phase or vapor phase in the presence of a catalyst comprising a carrier supporting sulfate ions to produce the corresponding dimethyltetralin. The catalyst supporting sulfate ions shows a high catalytic activity event at low temperatures. Therefore, the cyclization of 5-tolyl-pent-2-ene is conducted in a wide temperature range from low temperatures to high temperatures.
    Type: Grant
    Filed: February 14, 2000
    Date of Patent: January 7, 2003
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Youichi Kyuuko, Norio Fushimi, Makoto Takagawa
  • Patent number: 6452047
    Abstract: Highly pure, less colored aromatic polycarboxylic acids are produced from crude aromatic polycarboxylic acids by simple procedures at low production costs. The crude aromatic polycarboxylic acid is mixed with aliphatic amine or alicyclic amine in the presence of a solvent to precipitate crystals of amine salt of aromatic polycarboxylic acid. The crystals are dissolved in water and decomposed, thereby obtaining the highly pure aromatic polycarboxylic acids.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: September 17, 2002
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Ryusuke Shigematsu, Masayoshi Hayashi, Akio Hashimoto, Makoto Takagawa
  • Patent number: 6072098
    Abstract: There are disclosed an industrially advantageous process for efficiently producing highly pure 2,6-dimethylnaphthalene (DMN) in high yield from a mixture of DMN by carrying out in turn, the steps of isomerizing a mixture of DMN in the presence of a catalyst; crystallizing the isomerization reaction product in the presence of a solvent (e.g.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: June 6, 2000
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Makoto Takagawa, Ryusuke Shigematsu
  • Patent number: 5948949
    Abstract: A process for producing highly pure 2,6-dimethylnaphthalene in a high yield from a mixture of dimethylnaphthalene isomers in the presence of a solvent, such as an aliphatic or alicyclic saturated hydrocarbon. Highly pure 2,6-dimethylnaphthalene can be produced steadily for a long time by filtering the 2,6-dimethylnaphthalene crystal precipitated by the crystallizing by using a filtration apparatus, such as a rotary vacuum filter, peeling-off the filtered cake from a filter cloth and cleaning the filter cloth with a solvent, at a temperature not lower than a filtration temperature.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: September 7, 1999
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Makoto Takagawa, Ryusuke Shigematsu, Kuniaki Ageishi, Ko Kedo
  • Patent number: 5872291
    Abstract: Provided is a process for producing benzoyl chlorides which comprises reacting an aromatic aldehyde with chlorine in liquid phase in the presence of inert gas, whereby the generation of benzal chlorides by products whose separation is difficult can be suppressed.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: February 16, 1999
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Takeshi Koshikawa, Toshihiro Hashimoto, Makoto Takagawa
  • Patent number: 5859294
    Abstract: A process for producing a high-purity naphthalenedicarboxylic acid having an improved hue or an excellent hue from a crude naphthalenedicarboxylic acid obtained by the oxidation of dialkyl naphthalene, industrially advantageously at high yields, which comprises dissolving a crude naphthalenedicarboxylic acid obtained by the oxidation of dialkyl naphthalene in an aqueous solution containing an aliphatic amine, an alicyclic amine or acetonitrile, removing heavy metal components contained as impurities until the content of the heavy metal components based on the crude naphthalenedicarboxylic acid is 100 ppm or less, and heating the aqueous solution containing a naphthalenedicarboxylic acid amine salt to distill off the amine.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: January 12, 1999
    Assignee: Mitsubishi Gas Chemical Corporation, Inc.
    Inventors: Akio Hashimoto, Ryusuke Shigematsu, Kenichi Nakamura, Makoto Takagawa
  • Patent number: 5700944
    Abstract: A process for the production of a pyridinecarboxylic acid by the air-oxidation of an alkylpyridine in a liquid phase, in which the conversion of the alkylpyridine is high, the yield of the pyridinecarboxylic acid is therefore high, the content of impurities in the product is decreased, and unreacted raw material and an oxidation intermediate can be recycled without the adverse effect of accumulation of the catalyst and bromine component, the process comprising oxidizing an alkylpyridine with an oxygen-containing gas in a solvent in the presence of a catalyst formed of a heavy metal salt and a bromine compound, the solvent being a lower aliphatic monocarboxylic acid having a water content of 2 to 15% by weight, or the process comprising the step of catalytically hydrogenating an oxidation reaction mixture or an isolated pyridinecarboxylic acid in the presence of a catalyst of a metal belonging to the group VIII of the periodic table.
    Type: Grant
    Filed: May 8, 1996
    Date of Patent: December 23, 1997
    Assignee: Mitsubishi Gas Chemical Company
    Inventors: Toshihiro Hashimoto, Kenichi Nakamura, Makoto Takagawa
  • Patent number: 5659097
    Abstract: A process for producing a monoalkenyl aromatic hydrocarbon which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom at the .alpha.-position of a side chain (such as o-xylene) with a conjugated diene having 4 or 5 carbon atoms in the presence of a catalyst slurry prepared by adding an aromatic hydrocarbon compound to a catalyst comprising a alkali metal and an alkali metal compound. In the aforementioned process, it is particularly effective that the catalyst slurry is prepared by adding the aromatic hydrocarbon compound after the aromatic hydrocarbon compound has been deoxygenated and dehydrated by distillation, and the catalyst slurry thus prepared is supplied to the reaction system. According to the aforementioned process, an industrially useful monoalkenyl aromatic hydrocarbon compound, such as a monoalkenylbenzene, can be produced at a high selectivity, in a high yield, and with enhanced safety and stability for a long time.
    Type: Grant
    Filed: January 11, 1995
    Date of Patent: August 19, 1997
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Norio Fushimi, Makoto Takagawa
  • Patent number: 5606430
    Abstract: An image apparatus is provided with a bottom take-out type automatic paper feeding mechanism. Documents are sequentially taken out from a lowermost document by coaction of a paper feeding roller and a document separation pad which is elastically pressed against the paper feeding roller. A hopper is provided on which the documents are placed by stacking. Projections are provided on a document placement surface of the hopper or a paper feeding passage. The projections prevent the documents from being adhered to the hopper which has been electrostatically charged.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 25, 1997
    Assignees: Fujitsu Limited, PFU Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5599981
    Abstract: Provided is a process for producing alkylbenzoyl chloride which comprises reacting alkylbenzaldehyde with chlorine at a temperature of -10.degree. to 80.degree. C. under a pressure of 5 kg/cm.sup.2 or below in a liquid phase, whereby alkylbenzoyl chloride can be produced in a high yield and at a low price.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: February 4, 1997
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Norio Fushimi, Kenichi Nakamura, Makoto Takagawa
  • Patent number: 5537219
    Abstract: An image reading apparatus is provided with white reference sheets. The image reading image apparatus is movable between a first reading position at which an optical reading unit reads image information on a document supplied by an automatic paper feeding mechanism and a second reading position. The image reading apparatus regulates an absolute white level with respect to a light source.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: July 16, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5537225
    Abstract: An image reading apparatus has a reading unit including a light source lamp mounted on a unit frame arranged in a document reading portion. The image reading apparatus comprised as a lamp frame supporting the light source lamp. The lamp frame has a pin. Projections are pivotally arranged on a back side surface of the lamp frame at an interval in a longitudinal direction of the light source lamp. An upper end of the projections has a grip for grasping. One of the projections has an elongated hole for receiving the pin. The pin regulates an pivoting angle of the projection. Slit holes, in which the projections are fitted, are formed in the unit frame.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: July 16, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5527977
    Abstract: Their is disclosed a process for producing a monoalkenyl aromatic hydrocarbon compound (e.g. 5-(o-tolyl)-2-pentene) which comprises the steps of alkenylating a side chain of an aromatic hydrocarbon compound having at lease one hydrogen atom bonded to .alpha.-position of the side chain (e.g. alkylbenzene) by the use of a conjugated diene having 4 to 5 carbon atoms (e.g. 1-3 butadiene) in the presence an alkali metal-based catalyst supported on a carrier; removing at least part of the catalyst from the resultant reaction product by separating the same; inactivating and optionally removing the catalyst contained in the reaction product; and thereafter distilling the reaction produce in liquid form to separate and recover the objective monoalkenyl aromatic hydrocarbon compound.
    Type: Grant
    Filed: June 27, 1994
    Date of Patent: June 18, 1996
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Makoto Takagawa, Kenichi Nakamura, Kinji Kato, Akio Hashimoto, Takayo Sasaki
  • Patent number: 5510909
    Abstract: A paper feed roller (5) is divided into a first roller (5a) and a second roller (5b); a slit (58) through which about 10 to 20 sheets of documents can pass is formed between the first roller and a gate plate (57) opposite to this; and the paper fed out therefrom is fed out to a space between the second roller (5b) and a separation pad (7) in contact with this.Also, there is adopted a construction in which the pressing force of a paper conveyance spring is transformed by a slide cam sliding in a direction parallel to the paper feed roller; and the paper width detection sensor is assembled by a fitting construction.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: April 23, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minori Masuda, Makoto Takagawa
  • Patent number: 5504587
    Abstract: A paper feed roller (5) is divided into a first roller (5a) and a second roller (5b); a slit (58) through which about 10 to 20 sheets of documents can pass is formed between the first roller and a gate plate (57) opposite to this; and the paper fed out therefrom is fed out to a space between the second roller (5b) and a separation pad (7) in contact with this.Also, there is adopted a construction in which the pressing force of a paper conveyance spring is transformed by a slide cam sliding in a direction parallel to the paper feed roller; and the paper width detection sensor is assembled by a fitting construction.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: April 2, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5495060
    Abstract: There is disclosed a method for isomerizing dimethylnaphthalene (DMN) in liquid phase under atmospheric pressure by using a catalyst comprising hydrogen-form mordenite which has a molar ratio of silica to alumina (SiO.sub.2 /Al.sub.2 O.sub.3 ratio) of at least 100 and is molded by incorporating alumina as the molding aid therein. According to the above method, the objective 2,6-DMN minimized in the contents of impurities can stably be produced in high selectivity and high yield under mild reaction conditions for a long period of time, while side reactions and deterioration of the catalyst are suppressed to a minimum.
    Type: Grant
    Filed: March 17, 1994
    Date of Patent: February 27, 1996
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Makoto Takagawa, Ryusuke Shigematsu, Kazuo Nagagata
  • Patent number: 5493422
    Abstract: A paper feed roller (5) is divided into a first roller (5a) and a second roller (5b); a slit (58) through which about 10 to 20 sheets of documents can pass is formed between the first roller and a gate plate (57) opposite to this; and the paper fed out therefrom is fed out to a space between the second roller (5b) and a separation pad (7) in contact with this.Also, there is adopted a construction in which the pressing force of a paper conveyance spring is transformed by a slide cam sliding in a direction parallel to the paper feed roller; and the paper width detection sensor is assembled by a fitting construction.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 20, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5493417
    Abstract: A paper feed roller (5) is divided into a first roller (5a) and a second roller (5b); a slit (58) through which about 10 to 20 sheets of documents can pass is formed between the first roller and a gate plate (57) opposite to this; and the paper fed out therefrom is fed out to a space between the second roller (5b) and a separation pad (7) in contact with this.Also, there is adopted a construction in which the pressing force of a paper conveyance spring is transformed by a slide cam sliding in a direction parallel to the paper feed roller; and the paper width detection sensor is assembled by a fitting construction.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 20, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5491567
    Abstract: A paper feed roller (5) is divided into a first roller (5a) and a second roller (5b); a slit (58) through which about 10 to 20 sheets of documents can pass is formed between the first roller and a gate plate (57) opposite to this; and the paper fed out therefrom is fed out to a space between the second roller (5b) and a separation pad (7) in contact with this.Also, there is adopted a construction in which the pressing force of a paper conveyance spring is transformed by a slide cam sliding in a direction parallel to the paper feed roller; and the paper width detection sensor is assembled by a fitting construction.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 13, 1996
    Assignees: PFU Limited, Fujitsu Limited
    Inventors: Shuichi Morikawa, Masahiko Futatsuka, Satoshi Ishida, Yasunori Miyauchi, Minoru Masuda, Makoto Takagawa
  • Patent number: 5481055
    Abstract: A method for isomerizing dimethylnaphthalene (DMN) in the gaseous phase in the presence of a solvent comprising an aromatic hydrocarbon having a boiling point of at most 150.degree. C., e.g., benzene, under atmospheric pressure by using a catalyst comprising a hydrogen-form of mordenite. According to the method, the objective 2,6-DMN can be produced with a minimal content of impurities and the 2,6-DMN can be stably produced in high selectivity and high yield under mild reaction conditions for a long period of time, while suppressing side reactions.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: January 2, 1996
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Makoto Takagawa, Ryusuke Shigematsu, Takayo Sasaki