Patents by Inventor Leslie G. Berntson

Leslie G. Berntson 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: 4923714
    Abstract: Ceramic particulates useful as a proppant in hydraulic fracturing and in gravel packing operations is provided which comprises a ceramic (sometimes vitreous) core surrounded by an epoxy resin coating. Novolac epoxy resin compounds without any substantial acid soluble filler are used to coat ceramic particulates similar to those discloses in U.S. Pat. Nos. 4,680,230 and 4,632,876. The result is a product which combines the excellent solvent resistance of the ceramics with the acid resistance of the resin. The resin coating gives the added benefits of lower specific gravity and improved crush resistance.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: May 8, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: James L. Gibb, James A. Laird, Leslie G. Berntson
  • Patent number: 4869960
    Abstract: Ceramic particulate useful as a proppant in hydraulic fracturing and in gravel packing operations is provided which comprises a ceramic (sometimes vitreous) core surrounded by an epoxy resin coating. Novolac epoxy resin compounds without any substantial acid soluble filler are used to coat ceramic particulates similar to those disclosed in U.S. Pat. Nos. 4,680,230 and 4,632,876. The result is a product which combines the excellent solvent resistance of the ceramics with the acid resistance of the resin. The resin coating gives the added benefits of lower specific gravity and improved crush resistance.
    Type: Grant
    Filed: September 17, 1987
    Date of Patent: September 26, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: James L. Gibb, James A. Laird, Leslie G. Berntson