Patents by Inventor Charles S. Letcher

Charles S. Letcher 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).

  • Hydrocarbon polymers to improve the hardness of waxes
    Patent number: 4239546
    Abstract: This invention relates to the use of hydrocarbon polymers to improve the hardness of waxes. Blends of hydrocarbon polymers in soft waxes are unexpectedly harder than each component thereof. In addition the blending of hydrocarbon polymers into waxes has a lesser effect on the undesirable properties of (1) increased viscosities and (2) increased cloud points, than occurs when polyethylene are blended into wax.
    Type: Grant
    Filed: July 21, 1978
    Date of Patent: December 16, 1980
    Assignee: Petrolite Corporation
    Inventors: Stephen E. Russell, Phillip M. Story, Charles S. Letcher