Patents by Inventor Hyang-Ja You

Hyang-Ja You 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: 5730876
    Abstract: A multi-step membrane separation process whereby the natural polymer .alpha.-chitosan extracted from the shell of crustaceans, etc. can be simply separated and purified into low molecular weight chitosan or oligosaccharide chitosan in a high yield. A chitosan mixture of various molecular weights is reacted with an acid in the presence of enzyme while applying an ultrasonic treatment to the mixture and then, added with pure water to give an aqueous solution having a chitosan concentration of 1 to 50%. It is subjected to a continuous membrane filtration under a pressure and further to a second fractionation and separation technique employing a proper membrane according to a desired molecular weight cut-off, at least one time.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: March 24, 1998
    Assignee: Hyang-Ja You
    Inventors: Hyang-Ja You, Kil-Hyun Park, Yong-Ho Kim, Yong-Ju Kim, Jae-Hyeok Choi, Seon-Jeong Kim, Soon-Hong Lee