Patents by Inventor Wei (Helen) Li

Wei (Helen) Li 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: 7005185
    Abstract: An epoxy composition includes an epoxy resin, a latent curing agent, and a catalyst. The composition includes two epoxide groups per molecule, and the latent curing agent is preferably a dicyanopolyamide, and most preferably dicyandiamide. The catalyst includes 2,4-toluene bis dimethyl urea, preferably in a concentration exceeding 70% by weight. The composition can be used in prepregs. The relative concentrations of the epoxy resin, curing agent, and catalyst are selected to achieve desired properties, including specific curing times and temperatures, and glass transition temperatures that enable a cured resin composition to be removed from a mold after being heated to its curing temperature, without being cooled. Exemplary formulations have reduced cure times, at both high and low curing temperatures, as compared to prior art formulations.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: February 28, 2006
    Assignee: Toray Composites (America), Inc.
    Inventors: Wei (Helen) Li, Kishio Miwa
  • Publication number: 20040261660
    Abstract: Curable compositions, such as benzoxazine-based ones, are useful in applications within the aerospace industry, such as for example as a heat curable composition for use as a matrix resin or an adhesive, and form the basis of the present invention.
    Type: Application
    Filed: June 27, 2003
    Publication date: December 30, 2004
    Applicant: HENKEL LOCTITE CORPORATION
    Inventors: Wei Helen Li, Stanley L. Lehmann, Raymond S. Wong
  • Publication number: 20030082385
    Abstract: An epoxy composition including an epoxy resin, a latent amine curing agent, and a specific catalyst. Preferably, the epoxy resin includes two epoxide groups per molecule, and the latent amine curing agent is a dicyanopolyamide, most preferably, dicyandiamide. The specific catalyst is preferably 2,4-toluene bis dimethyl urea. A prepreg employing the epoxy composition of the present invention can achieve a 95% cure in about one half of the time required by a prepreg that differs only in the catalyst employed. Furthermore, prepregs employing the epoxy composition of the present invention have glass transition temperatures higher than the curing temperatures when cured at a temperature range from about 80° C. to about 150° C., enabling cured prepregs to be removed from molds without being cooled. Use of the prepregs of the present invention thus enables composite component manufacturers to substantially increase production rates without requiring the use of additional molds.
    Type: Application
    Filed: July 13, 2001
    Publication date: May 1, 2003
    Applicant: Toray Composites (America), Inc.
    Inventors: Wei (Helen) Li, Kishio Miwa