Patents by Inventor Edward L. Nielsen

Edward L. Nielsen 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).

  • Method of purifying bisphenols
    Patent number: 4927978
    Abstract: A process for the preparation of crystals of an adduct of a bisphenol with a phenol which comprises:(a) adding an inert volatile liquid hydrocarbon diluent and 0-1.5% weight water to a crude mixture of the bisphenol and the phenol at a temperature above the boiling temperature of the added volatile liquid diluent; and(b) allowing the volatile liquid diluent to boil in the process, thereby cooling the resulting mixture of bisphenol and phenol to a temperature at which adduct crystals form.
    Type: Grant
    Filed: December 16, 1988
    Date of Patent: May 22, 1990
    Assignee: Shell Oil Company
    Inventors: James L. Buechele, Edward L. Nielsen, Walter Dong, Paul V. Shaw