Patents by Inventor Akihiro Takazawa

Akihiro Takazawa 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).

  • Polyalkoxysiloxane and process for its production
    Patent number: 6258969
    Abstract: A polyalkoxysiloxane of the following rational formula: SiOa(OR)b(OH)c wherein R is a C1-4 alkyl group, a=0.86 to 1.30, b=2.18 to 1.30, and c≦0.10.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: July 10, 2001
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Takeshi Sawai, Hanako Kato, Seiichiro Tanaka, Akihiro Takazawa, Haruo Katsumata, Hozumi Endo
  • Silica gel, synthetic quartz glass powder and shaped product of quartz glass
    Patent number: 6225245
    Abstract: A synthetic quartz powder obtained by calcining a powder of silica gel, characterized in that white devitrification spots having sizes of larger than 20 &mgr;m in diameter formed in an ingot obtained by vacuum melting the synthetic quartz powder at a temperature of from 1780 to 1800° C. to form an ingot, followed by maintaining the ingot at a temperature of 1630° C. for 5 hours, are at most 10 spots/50 g.
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: May 1, 2001
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Akira Utsunomiya, Yoshio Katsuro, Akihiro Takazawa, Takashi Moriyama
  • Process for producing a high purity synthetic quartz
    Patent number: 6131409
    Abstract: A method for producing a high purity synthetic quartz powder, characterized by using a tetramethoxysilane having a trimethoxymethylsilane content of at most 0.3 wt %, and converting it to a synthetic quartz by a sol-gel method.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: October 17, 2000
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Yoshio Katsuro, Takanobu Katsuki, Akihiro Takazawa, Hanako Kato, Akira Utsunomiya