Patents by Inventor Guo-Mao Yang

Guo-Mao Yang 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).

  • Electrets
    Patent number: 6489033
    Abstract: Electrets can be produced from cycloolefin copolymers (COCs), and charges applied thereto are stable for long periods, even at high temperatures and high relative humidities. The reduction here in a positive charge applied to the COCs is smaller than that of negative charges applied to the COCs. The stability over time of the charges applied is impaired by adding polar additives, such as inorganic silicon compounds. Films, fibers or nonwovens produced from electrets can be processed to give filters.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: December 3, 2002
    Assignee: Ticona GmbH
    Inventors: Wilfried Hatke, Gerhard Sessler, Guo-Mao Yang