Patents by Inventor Michael V. Spencer

Michael V. Spencer 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 making cellulose ethers having reduced yellowing and discoloration
    Patent number: 6306333
    Abstract: A process for making a low molecular weight cellulose ether has the following steps: a) providing a high molecular weight cellulose ether; b) contacting it with acid to partially depolymerize it to a cellulose ether of a viscosity of about 100 cP or less; c) neutralizing the acid; d) repeating steps a)-c) to produce two or more discrete product batches of low molecular weight cellulose ether and produce at least one discrete product batch which is partially neutralized; and e) blending the two or more discrete product batches to form a combined product batch of low molecular weight cellulose ether of a pH of 4 to 6.8. The process provides a cellulose ether with reduced yellowing and discoloration.
    Type: Grant
    Filed: October 13, 1999
    Date of Patent: October 23, 2001
    Assignee: The Dow Chemical Company
    Inventors: Steven Rosenberg, Michael V. Spencer, Gary J. Schulz