Patents by Inventor Tomiharu Amitani

Tomiharu Amitani 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: 5175372
    Abstract: In a process of producing high purity bis(4-hydroxyphenyl)sulfides which comprises reacting phenols with sulfur dichloride in an organic solvent, the improvement comprising: reacting the phenols with sulfur dichloride in a nonpolar organic solvent; removing partly or wholly the nonpolar organic solvent after the reaction; adding a polar organic solvent to the reaction mixture to dissolve the reaction mixture therein at elevated temperatures; and crystallizing out the high purity bis(4-hydroxyphenyl)sulfides.There is further provided a high performance heat-sensitive recording material which comprises high purity bis(4-hydroxy-3-methylphenyl)sulfide thus prepared and having a melting point in the range of from 123.9.degree. C. to 124.9.degree. C. as a developer and a fluoran compound as a color former.
    Type: Grant
    Filed: April 10, 1991
    Date of Patent: December 29, 1992
    Assignee: Seitetsu Kagaku Co., Ltd.
    Inventors: Akira Onoe, Masao Kawamura, Kunioki Kato, Tomiharu Amitani, Makoto Sato, Tsuyoshi Morishita
  • Patent number: 5102858
    Abstract: In a process of producing high purity bis(4-hydroxyphenyl) sulfides which comprises reacting phenols with sulfur dichloride in organic solvents, the improvement comprising: reacting the phenols with sulfur dichloride in nonpolar organic solvents; removing partly or wholly the nonpolar organic solvents after the reaction; adding polar organic solvents to the reaction mixture to dissolve the reaction mixture therein at elevated temperatures; and crystallizing out the high purity bis(4-hydroxyphenyl)sulfides.There is further provided a high performance heat-sensitive recording material which comprises high purity bis(4-hydroxy-3-methylphenyl)sulfide thus prepared and having a melting point in the range of from 123.9.degree. C. to 124.9.degree. C. as a developer and a fluoran compound as a color former.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: April 7, 1992
    Assignee: Seitetsu Kagaku Co., Ltd.
    Inventors: Akira Onoe, Masao Kawamura, Kunioki Kato, Tomiharu Amitani, Makoto Sato, Tsuyoshi Morishita