Patents by Inventor Glen R. Ladewig

Glen R. Ladewig 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 obtaining high purity bisphenol A
    Patent number: 4354046
    Abstract: A method of purifying bisphenols by (1) crystallizing the crude bis from a single liquid phase containing water, bis and an organic solvent, (2) stripping the remaining mother liquor (containing the impurities) of solvent and water, and (3) mixing it with phenol, (4) contacting the mixture of phenol and mother liquor with a cation exchange resin to convert the impurity to the desired product, (5) stripping the phenol and (6) recycling the remainder to the initial crystallizing step.
    Type: Grant
    Filed: May 26, 1981
    Date of Patent: October 12, 1982
    Assignee: The Dow Chemical Company
    Inventors: Glen R. Ladewig, Feng-Chih Chang