Patents by Inventor Petrina M. Kelly

Petrina M. Kelly 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: 4824827
    Abstract: Disclosed are end point indicator compositions and devices containing them, particularly useful as air freshener devices, comprise compositions containing a polar indicator dye which assumes a first color or is colorless in the presence of a room temperature volatilizable solvent which is initially present in excess and a small amount of a proton donating compound. The indicator dye assumes a second color visually distinct from the first color in the presence of the proton donating compound after the majority of the solvent escapes from the remainder of the composition. Optionally, the compositions further include color change developers and/or secondary dyes to render the change to the second color, indicating attainment of the end point, more apparent to a user.
    Type: Grant
    Filed: February 5, 1988
    Date of Patent: April 25, 1989
    Assignee: S. C. Johnson & Son, Inc.
    Inventors: Petrina M. Kelly, Colin Berrido