Patents by Inventor Tsutomu Kushida

Tsutomu Kushida 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 purifying hydroxycarboxylic acid, process for producing cyclic ester, and process for producing polyhydroxycarboxylic acid
    Patent number: 7781600
    Abstract: Disclosed is a process for purifying a hydroxycarboxylic acid, comprising: a crystallization step of subjecting a hydroxycarboxylic acid aqueous solution to crystallization for purification, a separation step of separating a hydroxycarboxylic acid crystal from a mother liquid, and a washing step of washing the hydroxycarboxylic acid crystal for further purification with a washing liquid, wherein the washing liquid is a hydroxycarboxylic acid aqueous solution. The purified or refined hydroxycarboxylic acid obtained through the above process is suitably used as a starting material for production of a polyhydroxycarboxylic acid. The above process is suitably included in a process for producing a cyclic ester and a process for producing a polyhydroxycarboxylic acid.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: August 24, 2010
    Assignee: Kureha Corporation
    Inventors: Tomoyuki Ogawa, Tomohiro Hoshi, Tsutomu Kushida, Kentaro Otawara
  • Process For Purifying Hydroxycarboxylic Acid, Process For Producing Cyclic Ester, and Process For Producing Polyhydroxycarboxylic Acid
    Publication number: 20080214842
    Abstract: Disclosed is a process for purifying a hydroxycarboxylic acid, comprising: a crystallization step of subjecting a hydroxycarboxylic acid aqueous solution to crystallization for purification, a separation step of separating a hydroxycarboxylic acid crystal from a mother liquid, and a washing step of washing the hydroxycarboxylic acid crystal for further purification with a washing liquid, wherein the washing liquid is a hydroxycarboxylic acid aqueous solution. The purified or refined hydroxycarboxylic acid obtained through the above process is suitably used as a starting material for production of a polyhydroxycarboxylic acid. The above process is suitably included in a process for producing a cyclic ester and a process for producing a polyhydroxycarboxylic acid.
    Type: Application
    Filed: October 17, 2005
    Publication date: September 4, 2008
    Inventors: Tomoyuki Ogawa, Tomohiro Hoshi, Tsutomu Kushida, Kentaro Otawara