Patents by Inventor Leo F. Fitzpatrick

Leo F. Fitzpatrick 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: 4943425
    Abstract: A method of making high purity, dense silica of large particles size is described. Tetraethylorthosilicate is mixed with ethanol and is added to a dilute acid solution having a pH of about 2.25. The resulting solution is digested for about 5 hours, then 2N ammonium hydroxide is added to form a gel at a pH of 8.5. The gel is screened through an 18-20 mesh screen, vacuum baked, calcined in an oxygen atmosphere and finally heated to about 1200.degree. C. in air to form a large particle size, high purity, dense silica.
    Type: Grant
    Filed: April 1, 1988
    Date of Patent: July 24, 1990
    Assignee: GTE Laboratories Incorporated
    Inventors: Sophia R. Su, Leo F. Fitzpatrick
  • Patent number: 4940571
    Abstract: A method of making large particle size, high purity, dense silica is described. Tetraethylorthosilicate ethanol solution is added to a 2N ammonium hydroxide solution containing silicic acid having an average particle size of about 15 micrometers to form a precipitate followed by a digestion of the precipitate in the solution. The precipitate is filtered through a screen having 45 micrometer openings and dried to form a dried powder. The dried powder is then calcined in an oxygen atmosphere followed by densifying it by heating at a temperature of about 1200.degree. C. in air to form a large particle size, high purity, dense silica.
    Type: Grant
    Filed: April 1, 1988
    Date of Patent: July 10, 1990
    Assignee: GTE Laboratories Incorporated
    Inventors: Sophia R. Su, Leo F. Fitzpatrick, Sheryl A. Robillard