Patents by Inventor Minoru Takagawa

Minoru 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).

  • Method for decomposing an aromatic aldehyde-hydrogen fluoride-boron fluoride complex
    Patent number: 4036885
    Abstract: This invention relates to a two-step method for decomposing an aromatic aldehyde-hydrogen fluoride-boron trifluoride complex in the presence of benzene as a diluent to obtain an aromatic aldehyde, hydrogen fluoride and boron trifluoride separately without causing any change in the quality of the aromatic aldehyde or without forming undesirable byproducts.
    Type: Grant
    Filed: February 2, 1976
    Date of Patent: July 19, 1977
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Susumu Fujiyama, Minoru Takagawa, Shiro Kajiyama
  • Method for decomposing an aromatic aldehyde-hydrogen fluoride-boron trifluoride complex
    Patent number: 3988424
    Abstract: A method for decomposing an aromatic aldehyde-hydrogen fluoride-boron trifluoride complex in the presence of a decomposing agent represented by the formula ##SPC1##Wherein n is integer of 1-6, inclusive, and m is integer of 0-5, inclusive, and a total of n and m is 6 or less, to obtain an aromatic aldehyde, hydrogen fluoride and boron trifluoride separately without causing any change in the quality of the aromatic aldehyde or without forming undesirable byproducts is disclosed.
    Type: Grant
    Filed: December 11, 1975
    Date of Patent: October 26, 1976
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Susumu Fujiyama, Takehiko Takahashi, Minoru Takagawa, Shigeki Ozao
  • Method for decomposing an aromatic aldehyde-hydrogen fluoride-boron fluoride complex
    Patent number: 3962343
    Abstract: This invention relates to a two-step method for decomposing an aromatic aldehyde-hydrogen fluoride-boron trifluoride complex in the presence of benzene as a diluent to obtain an aromatic aldehyde, hydrogen fluoride and boron trifluoride separately without causing any change in the quality of the aromatic aldehyde or without forming undesirable byproducts.
    Type: Grant
    Filed: May 8, 1974
    Date of Patent: June 8, 1976
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Susumu Fujiyama, Minoru Takagawa, Shiro Kajiyama
  • Process for purifying p-tolualdehyde
    Patent number: 3956394
    Abstract: P-Tolualdehyde is separated with a high purify from a mixture of tolualdehyde isomers having a mole fraction of p-tolualdehyde of at least 0.27, on the basis of total tolualdehyde isomers by cooling the mixture to a crystallization temperature of -6.degree. to -60.degree.C, thereby crystallizing p-tolualdehyde, and separating the resulting p-tolualdehyde crystals from mother liquor. A solvent such as an aliphatic hydrocarbon having 1 to 9 carbon atoms or an alicyclic hydrocarbon having 3 to 9 carbon atoms can be added to the mixture before cooling to improve the crystallization conditions. The resulting crystals can be washed with a washing agent, such as said solvent, to remove the other isomers adhering to the crystals.
    Type: Grant
    Filed: September 30, 1974
    Date of Patent: May 11, 1976
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Susumu Fujiyama, Minoru Takagawa