Patents Represented by Attorney Willam F. Marsh

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  • Elevated pressure phthalic anhydride process
    Patent number: 5210223
    Abstract: The present invention is an improvement to the conventional process for the production of phthalic anhydride. In particular, the present invention enables the crude phthalic anhydride product to be recovered in a more efficient manner.
    Type: Grant
    Filed: June 17, 1992
    Date of Patent: May 11, 1993
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Michael S. Chen, Philip J. Cook, Harold H. Gunardson, Melinda B. Ulrich