Patents by Inventor Bruce B. Johnson

Bruce B. Johnson 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).

  • Perfluoroalkylated diaminomesitylene and polyimides therefrom
    Patent number: 5177179
    Abstract: Perfluoroalkylated diaminoesitylene and polymers, preferably polyimides, made therefrom. The necessarily obtainable meta-substitution position of the perfluoroalkyl group with respect to both amino-groups provides an improved diamine and compositions of matter resulting therefrom.
    Type: Grant
    Filed: April 4, 1991
    Date of Patent: January 5, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Brian C. Auman, David P. Higley, Bruce B. Johnson
  • Multilayer cation exchange membrane
    Patent number: 4686120
    Abstract: A cation exchange membrane is disclosed comprising fluorinated polymer layers which include, in order, a layer with sulfonic exchange groups, a layer with carboxylic exchange groups, and a thinner layer with carboxylic exchange groups at a greater exchange capacity than the other carboxylic layer.
    Type: Grant
    Filed: April 28, 1986
    Date of Patent: August 11, 1987
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Bruce B. Johnson
  • Multilayer cation exchange membrane
    Patent number: 4604323
    Abstract: A cation exchange membrane is disclosed comprising fluorinated polymer layers which include, in order, a layer with sulfonic exchange groups, a layer with carboxylic exchange groups, and a thinner layer with carboxylic exchange groups at a greater exchange capacity than the other carboxylic layer.
    Type: Grant
    Filed: February 22, 1985
    Date of Patent: August 5, 1986
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Bruce B. Johnson