Patents by Inventor Yasuo Takakuwa

Yasuo Takakuwa 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 preparing optically active 2-(4-hydroxy-phenoxy) propionic acid compounds
    Patent number: 4625053
    Abstract: A process for preparing an optically active 2-(4-hydroxyphenoxy)propionic acid compound, which comprises reacting an optically active compound having the formula: ##STR1## wherein X is a chlorine atom or a bromine atom, and M is a hydrogen atom or an alkali metal atom, with hydroquinone or an alkali metal salt of hydroquinone, in the presence of an alkali metal hydroxide and water, and precipitating optically active disodium 2-(4-hydroxyphenoxy)propionate.
    Type: Grant
    Filed: November 6, 1985
    Date of Patent: November 25, 1986
    Assignee: Nissan Chemical Industries Ltd.
    Inventors: Shoji Fujinawa, Isao Hashiba, Kenji Suzuki, Syuzi Tsuchiya, Yasuo Takakuwa
  • Process for preparing D-.alpha.-(6-methoxy-2-naphtyl) propionic acid
    Patent number: 4611088
    Abstract: A process for preparing d-.alpha.-(6-methoxy-2-naphthyl)propionic acid, which comprises hydrolyzing an ester of d-.alpha.-(6-methoxy-2-naphthyl)propionic acid in an aqueous solution containing a basic catalyst.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: September 9, 1986
    Assignee: Nissan Chemical Industries, Ltd.
    Inventors: Yoshio Ohara, Kazutaka Arai, Yasuhiro Takahashi, Yasuo Takakuwa
  • Process for preparing an optical active ester of naphthylpropionic acid
    Patent number: 4417070
    Abstract: Disclosed is a process for preparing an optical active alkyl ester of .alpha.-(6-methoxynaphth-2-yl)propionic acid from the racemic modification thereof or from a mixture of the optical isomers thereof by preferential crystallization. The efficiency of the optical resolution can be increased by adding a base which facilitates the racemization. The process comprises dissolving the racemic modification or the optical isomers in an organic solvent such as methanol, ethanol, etc., with or without a base such as sodium methoxide, sodium ethoxide, etc., and seeding seed crystals of one of the optical isomers to effect crystallization for optical resolution.
    Type: Grant
    Filed: April 9, 1982
    Date of Patent: November 22, 1983
    Assignee: Nissan Chemical Industries, Ltd.
    Inventors: Kazutaka Arai, Yoshio Ohara, Yasuo Takakuwa, Toyoko Iizumi
  • Melamine cyanurate as a flame retardant agent
    Patent number: 4180496
    Abstract: A flameproof resin composition comprising the admixture of 3 to 30 wt. % of an adduct of 2,4,6-triamino-1,3,5-triazine and 2,4,6-trihydroxy-1,3,5-triazine and/or a tautomer thereof with a linear polyester.
    Type: Grant
    Filed: January 3, 1978
    Date of Patent: December 25, 1979
    Assignee: Nissan Chemical Industries Ltd.
    Inventors: Akira Yanagimoto, Shunichi Kumazawa, Yasuo Takakuwa