Patents by Inventor Harold K. Sinclair

Harold K. Sinclair 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: 5492500
    Abstract: The oxidation resistance of elastomeric balloons made from natural rubber is greatly improved by coating the exterior of the balloon with a film of uncured elastomer, preferably neoprene. The uncured elastomer coating maintains the clarity of the inflated balloons. These balloons are particularly useful as containers for gifts or in balloon sculpture.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: February 20, 1996
    Assignee: Hi-Float Co., Inc.
    Inventors: Harold K. Sinclair, Donald K. Burchett
  • Patent number: 5244429
    Abstract: Polyvinyl alcohol coatings used to improve the bouyant life of elastomeric balloons include polyvinyl alcohol and a water soluble carbohydrate extender such as dextrose, at levels up to four times the weight of the polyvinyl alcohol. The improved coatings of the present invention typically give double the floating life of the balloon under a wide range of humidities.
    Type: Grant
    Filed: May 18, 1992
    Date of Patent: September 14, 1993
    Assignee: Hi-Float Co., Inc.
    Inventor: Harold K. Sinclair
  • Patent number: 4225476
    Abstract: Adhesive blend of wood rosin and a thermoplastic graft copolymer prepared by heating for about 15 seconds to 60 minutes, with mixing, a trunk copolymer of at least two monomers, at least one of said monomers providing amine-reactive sites taken from the group consisting of the anhydride group, e.g., maleic anhydride; a vicinal pair of carboxylic groups and a carboxylic acid adjacent to an alkoxycarbonyl group, wherein the alkoxy group contains up to 20 carbon atoms, and at least one of said monomers containing no amine-reactive sites, and at least one side chain polymer having per chain one active amine site taken from the group consisting of primary and secondary amines, the remainder of said side chain polymer being substantially unreactive with the reactive sites, e.g., amino-substituted polycaprolactam, polylaurolactam, polyethylene oxide, etc., of the trunk copolymer.
    Type: Grant
    Filed: May 14, 1976
    Date of Patent: September 30, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Clarence F. Hammer, Harold K. Sinclair
  • Patent number: RE30322
    Abstract: 6-Nylons and 12-nylons having primary amino end-groups and an average degree of polymerization of about 5-60 are grafted onto elastomeric trunk polymers having anhydride groups, vicinal carboxylic groups, or carboxylic groups adjacent to alkoxycarbonyl groups by heating a mixture of the nylon and the trunk polymer, preferably under high shear conditions for about 1 minute or less to 30 minutes or more above the melting temperature of the nylon. The resulting elastomeric graft polymers are suitable for fabricating into a variety of articles, such as, for example, wire jacketing, hose, belts, seals, gaskets, and low pressure tires.
    Type: Grant
    Filed: December 15, 1978
    Date of Patent: July 1, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Clarence F. Hammer, Harold K. Sinclair
  • Patent number: RE30754
    Abstract: Process for the preparation of thermoplastic graft copolymers which comprises heating for about 15 seconds to 60 minutes, with mixing, a trunk copolymer of at least two monomers, at least one of said monomers providing amine-reactive sites taken from the group consisting of the anhydride group, e.g., maleic anhydride; a vicinal pair of carboxylic groups and a carboxylic acid adjacent to an alkoxycarbonyl group, wherein the alkoxy group contains up to 20 carbon atoms, and at least one of said monomers containing no amine-reactive sites, and at least one side chain polymer having per chain one active amine site taken from the group consisting of primary and secondary amines, the remainder of said side chain polymer being substantially unreactive with the reactive sites, e.g., amino-substituted polycaprolactam, polylaurolactam, polyethylene oxide, etc., of the trunk copolymer. The process provides control of the type and length of the side chain polymer grafted onto the trunk copolymer.
    Type: Grant
    Filed: December 15, 1978
    Date of Patent: September 29, 1981
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Clarence F. Hammer, Harold K. Sinclair