Patents by Inventor Noritoshi Ishida

Noritoshi Ishida 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).

  • Process for the production of methylene-crosslinked polyphenylene polyisocyanate
    Patent number: 5364958
    Abstract: The hue of a methylene-crosslinked polyphenylene polyisocyanate continuously produced by the reaction with phosgene in an inert solvent of a polyamine mixture obtained by condensation of aniline and formaldehyde in the presence of an acid catalyst is improved by first removing any residual phosgene followed by heat treatment in the presence of hydrogen chloride gas.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: November 15, 1994
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Noritoshi Ishida, Zunzi Tashima, Naoki Sato, Michiya Takasaki, Masaaki Iijima, Kazuyuki Kuroda, Kazunari Nitta
  • Fractionation process of reaction mixture containing methylene bridged polyphenylene polyisocyanate
    Patent number: 5179227
    Abstract: A fractionation process of a methylene bridged polyphenylene polyisocyanate mixture obtained by phosgenating condensation product of aniline and formaldehyde is disclosed.In order to apply the above mixture to a variety of uses, the process separates the mixture into fractions by giving primary attention to the content of 4,4'-and 2,4'-isomer of diphenylmethane diisocyanate and at the same time reduces the content of impurities having acidity and hydrolyzable chlorine.
    Type: Grant
    Filed: October 23, 1991
    Date of Patent: January 12, 1993
    Assignee: Mitsui Toatsu Chemicals Inc.
    Inventors: Noritoshi Ishida, Zunzi Tashima, Mitsunori Shimamatsu, Kazunari Nitta, Takashi Nagou
  • Methylene-crosslinked polyarylamine and process for preparing same
    Patent number: 5053539
    Abstract: A methylene-crosslinked polyarylamine is disclosed which contains a less amount of N-methylmethylenedianiline. A process for continuously preparing this kind of methylene-crosslinked polyarylamine is also revealed which comprises reacting aniline with formalin in the presence of hydrochloric acid under specific reaction conditions.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: October 1, 1991
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Naoyuki Yano, Tatsuya Nagayoshi, Takashi Nagou, Zunzi Tashima, Noritoshi Ishida, Hiroyuki Itoh, Katsuyuki Nagamatsu