Patents Assigned to Mallinckrodt Specialty Chemicals Co.
  • Process for preparing aromatic fluorides
    Patent number: 5107046
    Abstract: An improved process is disclosed for preparing aromatic fluorides by diazotization-fluorination in hydrogen fluoride. The improvement includes, prior to the decomposition of the diazonium fluoride, adding to the diazotizing reaction mixture, urea or a salt thereof in an amount sufficient to reduce the vapor pressure of hydrogen fluoride over the diazonium solution. Also disclosed is a process for reducing the vapor pressure over diazonium fluoride solutions.
    Type: Grant
    Filed: May 23, 1990
    Date of Patent: April 21, 1992
    Assignee: Mallinckrodt Specialty Chemicals Co., Inc.
    Inventor: Gary L. Cantrell
  • Process for the continuous recovery of hydrogen fluoride gas
    Patent number: 5032371
    Abstract: A continuous process for the recovery of anhydrous hydrogen fluoride gas by contacting an aqueous solution of an alkali metal fluoride in hydrofluoric acid with a sulfur-containing dehydrating stream. The dehydrating stream preferably consists of sulfur trioxide dissolved in sulfuric acid. The desired product is obtained in high yield and purity.
    Type: Grant
    Filed: July 7, 1989
    Date of Patent: July 16, 1991
    Assignee: Mallinckrodt Specialty Chemicals Co.
    Inventor: Henry J. Buehler