Patents by Inventor Elizabeth A. Efford

Elizabeth A. Efford 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).

  • Process for preparing static dissipative linear segmented polyurethanes
    Patent number: 4939204
    Abstract: This invention is an improvement in a process for preparing an static dissipative phase-segregated polyurethane polymer wherein a polyfunctional polyether and a chain extender are reacted with an organic polyisocyanate in the presence of about 500 to 10,000 parts per million metal tetraorganoboron salt or fluorinated alkylsulfonate salt, based on the weight of the polyurethane. The improvement comprises dissolving said salt in all or a portion of said chain extender prior to contacting said chain extender with said polyfunctional polyether and said polyisocyanate.This process provides a phase-segregated polyurethane having excellent static dissipative properties.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: July 3, 1990
    Assignee: The Dow Chemical Company
    Inventor: Elizabeth A. Efford
  • Control of yellow color in polyether polyols
    Patent number: 4751331
    Abstract: Polyether polyols are decolorized by heating to a temperature in excess of 95.degree. C. in the presence of water and air. The resulting polyols have minimal residual color, and can be used to prepare polyurethanes having low color.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: June 14, 1988
    Assignee: The Dow Chemical Company
    Inventor: Elizabeth A. Efford