Patents by Inventor Francis J. Walczak

Francis J. Walczak 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).

  • Patent number: 6329559
    Abstract: A process is disclosed for the manufacture of CF3CF═CF2, and optionally a least one compound selected from CF3CH2CF3 and CF3CHFCHF2. The process involves contacting a reactor feed including a precursor stream of at least one halogenated propane of the formula CX3CH2CHyX(3−y) and/or halogenated propene of the formula CX3CH═CHyX(2−y), where each X is Cl or F and y is 0, 1 or 2 (provided that the average fluorine content of the precursor stream is no more than 5 fluorine substituents per molecule) with HF and Cl2 in a chlorofluorination reaction zone containing a fluorination catalyst and operating at a temperature between about 150° C. and 400° C.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: December 11, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Allen Capron Sievert, V. N. Mallikarjuna Rao, Francis J. Walczak
  • Patent number: 5563304
    Abstract: CF.sub.3 CHFCHF.sub.2 production is disclosed which involves reacting CF.sub.3 CF.dbd.CHF with HF at an elevated temperature over a catalyst selected from the group consisting of aluminum fluoride, fluorided alumina, metals supported on aluminum fluoride, metals supported on fluorided alumina and catalysts comprising trivalent chromium. Also disclosed is enrichment of CF.sub.3 CF.dbd.CHF from a starting mixture containing CF.sub.3 CF.dbd.CHF and CF.sub.3 CH.dbd.CF.sub.2 which involves reacting said starting mixture with HF at an elevated temperature over a catalyst consisting essentially carbon, a catalyst consisting essentially of metal halides supported on carbon, a catalyst consisting essentially of Cr.sub.2 O.sub.3, or mixtures thereof (provided that when Cr.sub.2 O.sub.3 is present the temperature is about 250.degree. C. or less) to produce a product mixture containing CF.sub.3 CH.sub.2 CF.sub.3 and unreacted CF.sub.3 CF.dbd.CHF wherein the mole ratio of CF.sub.3 CF.dbd.CHF to CF.sub.3 CH.dbd.CF.sub.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: October 8, 1996
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: V. N. Mallikarjuna Rao, Francis J. Walczak