Patents by Inventor Michael C. Hall

Michael C. Hall 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).

  • Carboxylated cellulose ion-exchange materials
    Patent number: 4260740
    Abstract: A process for preparing a carboxylated cellulose ion exchange material which comprises heating a mixture of cellulose and citric, isocitric or aconitic acid at a temperature of from about 100.degree. to 160.degree. C. while removing water, and then treating the product with aqueous alkali at a pH of 8 to 11 to hydrolyze cross-linked acid residues; carboxylated cellulose ion exchange materials prepared by the process and their use in removing heavy-metal ions from aqueous solutions such as in industrial effluent treatment and precious metal recovery.
    Type: Grant
    Filed: October 10, 1979
    Date of Patent: April 7, 1981
    Assignee: Pfizer Inc.
    Inventors: Roy Carrington, Michael C. Hall