Patents by Inventor Donald D. May

Donald D. May 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: 5460891
    Abstract: Polyamide fibrous substrates which resist staining by acid dyes and discoloration upon exposure to UV light, and processes for preparing the same which comprise applying, at pH 2 to 10, a base-catalyzed condensation product formed by the reaction of a bis(hydroxyphenyl)sulfone with formaldehyde to give a product known as a resole.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: October 24, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert C. Buck, Engelbert Pechhold, Donald D. May
  • Patent number: 5447755
    Abstract: Polyamide fibrous substrates which resist staining by acid dyes and discoloration upon exposure to UV light, and processes for preparing the same which comprise applying, at pH 2 to 10, a base-catalyzed condensation product formed by the reaction of a bis(hydroxyphenyl)sulfone with formaldehyde to give a product known as a resole.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: September 5, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Engelbert Pechhold, Robert C. Buck, Donald D. May
  • Patent number: 5427859
    Abstract: Fluoroalkyl- snbstituted maleic anhydride polymers, substrates treated therewith, and to novel processes for preparing and using the same. The polymers can be prepared by reacting: (1) terminally unsaturated alkenylamines or alcohols (e.g. allyl amine or alcohol, or diatlyl amine)with maleic anhydride polymers, and (2) the resulting polymeric amides or esters with fluoroalkyl iodides in the presence of a free radical initiator. Dehydroiodination of the resulting product with base yields novel polymeric products which provide oil- and water-repellency as well as soil-resistance when applied to substrates particularly nylon fibers.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: June 27, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Donald D. May
  • Patent number: 5408010
    Abstract: Fluoroalkyl-substituted maleic anhydride polymers, substrates treated therewith, and to novel processes for preparing and using the same. The polymers can be prepared by reacting: (1) terminally unsaturated alkenylamines or alcohols (e.g. allyl amine or alcohol, or diallyl amine) with maleic anhydride polymers, and (2) the resulting polymeric amides or esters with fluoroalkyl iodides in the presence of a free radical initiator. Dehydroiodination of the resulting product with base yields novel polymeric products which provide oil- and water-repellency as well as soil-resistance when applied to substrates, particularly nylon fibers.
    Type: Grant
    Filed: July 28, 1994
    Date of Patent: April 18, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Donald D. May
  • Patent number: 5276194
    Abstract: A process is provided for the catalytic perfluoroalkylation of aromatic compounds, wherein a perfluoroalkyl iodide or mixture of iodides is reacted with an aromatic compound in the presence of an aqueous base, such as an alkali metal hydroxide or carbonate. The use of an aqueous strong base increases the rate of reaction. Further improvements in rate and yield are secured by employing, as the catalyst, a noble metal supported on porous silica microspheres.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: January 4, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Donald D. May
  • Patent number: 5233104
    Abstract: Aromatic compound are trifluoromethylated by reaction in the vapor phase with a dihalodifluoromethane in the presence of a copper/copper fluoride catalyst.
    Type: Grant
    Filed: August 27, 1992
    Date of Patent: August 3, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Donald D. May
  • Patent number: 5068436
    Abstract: A method for inhibiting dehalogenation of fluorinated and chlorinated benzenoid nitro compounds during catalytic hydrogenation to make the corresponding substituted anilines by conducting the hydrogenation reaction in the presence of an acidic catalytic medium.
    Type: Grant
    Filed: March 10, 1989
    Date of Patent: November 26, 1991
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Donald D. May