Patents by Inventor Masaaki Yazawa

Masaaki Yazawa 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).

  • Diamino compound and production process for the same
    Patent number: 6476266
    Abstract: Provided is a diamino compound suitable for obtaining a polyimide which can form a liquid crystal alignment film capable of providing a liquid crystal display element, an intermediate therefor and a production process for the same. The above production process is characterized by reacting a cyclohexylbenzene derivative represented by Formula (3): with an acid halide represented by Formula (4): by the Frieldel-Crafts reaction to produce a cyclohexylphenylcarbonyl compound, and reducing the above compound after nitrating, whereby a compound represented by Formula (1) is obtained: (wherein A1 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; A2 represents a single bond or an alkylene group having 1 to 5 carbon atoms, and one or optional methylene groups which are not adjacent in the group may be substituted with an oxygen atom; X is Br or Cl; m represents an integer of 0 to 3, and n represents an integer of 1 to 5).
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: November 5, 2002
    Assignee: Chisso Corporation
    Inventors: Takahiro Mori, Toshiya Sawai, Shizuo Murata, Masaaki Yazawa, Satoshi Tanioka, Kumiko Hara
  • Polyamic acid, polyimide film and liquid crystal aligning film and liquid crystal display element using the formers
    Patent number: 5807961
    Abstract: This invention is directed to a polyimide film useful as use applications for electronic materials; a liquid crystal aligning film using the same; a liquid crystal display element provided with the liquid crystal aligning film; and a polyamic acid used as a raw material of the polyimide constituting the polyimide film.The polyimide used for preparing the above polyimide films, consists of a diamine component, the 50% by mol or more based upon the total diamine, of which is a diamine having a core structure having no polar group such as 1,2-bis(4-(4-aminobenzyl)phenyl)ethane, 1,6-bis(4-(4-aminobenzyl)phenyl)hexane, 1,1-bis(4-(4-aminobenzyl)phenyl)heptane, etc., and a tetracarboxylic acid dianhydride, and if necessary, an aminosilicon compound, is used as a liquid crystal aligning film.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: September 15, 1998
    Assignee: Chisso Corporation
    Inventors: Toshiya Sawai, Masaaki Yazawa, Seiji Oikawa, Shizuo Murata, Masaharu Hayakawa, Etsuo Nakagawa
  • Diamino compounds and methods for preparing them
    Patent number: 5663440
    Abstract: An object of the invention is to propose diamino compounds expressed by the following general formula (1) which are suitable to obtain a raw material, a polyimide resin, for a liquid crystal aligning film without any image sticking and with a high voltage holding ratio at from a low temperature to a high temperature as well as the preparation thereof: ##STR1##
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: September 2, 1997
    Assignee: Chisso Corporation
    Inventors: Toshiya Sawai, Seiji Oikawa, Masaaki Yazawa, Shizuo Murata, Masaharu Hayakawa, Etsuo Nakagawa, Shinichi Sawada