Patents by Inventor Clare A. Stewart, Jr.

Clare A. Stewart, Jr. 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).

  • Use of vinyl alcohol homopolymer and copolymers for tableting active materials
    Patent number: 4990335
    Abstract: Method of making tablets for active ingredient delivery by compressing a mixture of active ingredient and granular, high viscosity, fully hydrolyzed polyvinyl alcohol or copolymer of vinyl alcohol with methyl acrylate or methyl methacrylate. By use of a crystalline, heat treated polymer, a tablet providing quick active ingredient release is obtained. By using an amorphous, non-heat treated polymer a tablet providing prolonged active ingredient release is obtained. By using blends of crystalline and amorphous polymers, tablets having a range of active ingredient release characteristics can be obtained. The granular, high viscosity, fully hydrolyzed polymers provide flowability, compressibility and processing versatility advantages over conventional tablet binders.
    Type: Grant
    Filed: May 12, 1988
    Date of Patent: February 5, 1991
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Linda R. Bateman, Robert C. Di Luccio, Clare A. Stewart, Jr., Donna L. Visioli, David P. Beach-Coffin
  • Process for the manufacture of chloroprene
    Patent number: 4605800
    Abstract: An improved process for the catalytic dehydrochlorination of 3,4-dichlorobutene-1 with aqueous alkali, wherein the effluent from the dehydrochlorination reactor is separated into phases, and the organic phase is steam-stripped at low temperature (below about 80.degree. C.) to recover chloroprene product, while the steam stripper heels are returned to the dehydrochlorination reactor. A small portion of the heels are purged prior to being recycled. Most of the catalyst is recovered and returned to the reaction, but a small amount of make-up catalyst is added. Chloroprene made in this process is a valuable monomer which finds use in the manufacture of a broad line of synthetic elastomers of considerable industrial interest.
    Type: Grant
    Filed: January 17, 1983
    Date of Patent: August 12, 1986
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Joseph F. Englert, Jr., Louis J. Maurin, III, Clare A. Stewart, Jr.
  • Fluoropolymer hexafluoropropene, tetrafluorethene and 1,1-difluoroethene
    Patent number: 4335238
    Abstract: Terpolymer consisting of 12 to 48% by weight TFE units, 7 to 24% by weight HFP units and 30 to 81% by weight VF.sub.2 units, provided that when the content of TFE units is less than 42% by weight, the content of HFP units is less than 15% by weight. Heat-stable films such as polyimide film can be coated with a coating comprising the terpolymer to provide heat-sealable film useful as wire insulation.
    Type: Grant
    Filed: October 6, 1980
    Date of Patent: June 15, 1982
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Albert L. Moore, Clare A. Stewart, Jr., Isadore Swerlick
  • Fluoroelastomer composition
    Patent number: 4123603
    Abstract: An elastomeric fluoropolymer having improved low temperature properties is provided. The composition contains polymerized units of 57-61 weight % vinylidene fluoride, 27-31 weight % hexafluoropropene, and 10-14 weight % tetrafluoroethylene.
    Type: Grant
    Filed: May 31, 1977
    Date of Patent: October 31, 1978
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Clare A. Stewart, Jr.