Patents by Inventor Donald J. Progar

Donald J. Progar 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: 5147966
    Abstract: The invention is a novel polyimide prepared from 3,4'-oxydianiline (3,4'-ODA) and 4,4'-oxydiphthalic anhydride (ODPA), in 2-methoxyethyl ether (diglyme). The polymer has been prepared in ultra high molecular weight and in a controlled molecular weight form which has a 2.5 percent offset is stoichiometry (excess diamine) with a 5.0 percent level of phthalic anhydride as an endcap. This controlled molecular weight form allows for greatly improved processing of the polymer for moldings, adhesive bonding, and composite fabrication. The higher molecular weight version affords tougher films and coatings. The overall polymer structure groups in the dianhydride, the diamine, and a metal linkage in the diamine affords adequate flow properties for making this polymer useful as a molding powder, adhesive, and matrix resin.
    Type: Grant
    Filed: July 31, 1990
    Date of Patent: September 15, 1992
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Terry L. St. Clair, Donald J. Progar
  • Patent number: 4937317
    Abstract: A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: June 26, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: J. Richard Pratt, Terry L. St. Clair, Donald J. Progar
  • Patent number: 4837300
    Abstract: Novel copolyimides are prepared by reacting one or more aromatic dianhydrides with a meta-substituted phenylene diamine and an aromatic bridged diamine. The incorporation of meta-substituted phenylene diamine derived units and bridged aromatic diamine derived units into the linear aromatic polymer backbone results in a copolyimide of improved flexibility, processability, and melt-flow characteristics. The novel copolyimides are especially useful as thermoplastic hot-melt adhesives.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: June 6, 1989
    Assignee: The United States of America as represented by the Administration of the National Aeronautics and Space Administration
    Inventors: Terry L. St. Clair, Harold D. Burks, Donald J. Progar
  • Patent number: 4488335
    Abstract: The invention relates to a hot melt adhesive attachment pad for releasably securing distinct elements together and particularly useful in the construction industry or a spatial vacuum environment. The attachment pad consists primarily of a cloth 11 selectively impregnated with a charge of hot melt adhesive 12, a thermo-foil heater 13 and a thermo-cooler 14. These components are securely mounting in a mounting assembly 17 and 18. In operation, the operator activates the heating cycle transforming the hot melt adhesive to a substantially liquid state, positions the pad against the attachment surface, and activates the cooling cycle solidifying the adhesive and forming a strong, releasable bond.
    Type: Grant
    Filed: July 22, 1983
    Date of Patent: December 18, 1984
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert L. Fox, Alan W. Frizzill, Bruce D. Little, Donald J. Progar, Robert H. Coultrip, Richard H. Couch, John R. Gleason, Bland A. Stein, John D. Buckley, Terry L. St. Clair
  • Patent number: 4420518
    Abstract: A package assembly for precisely positioning a charge of hot melt adhesive 37 onto an attachment pad (13, 15, 17) or point of use wherein the adhesive is heated to softening or melt temperature (280.degree. F.-325.degree. F.) and thereafter cooled to resolidifying temperature. A single sided pressure sensitive polyimide film tape 40 serves with another film strip 39 to protect sandwiched adhesive strip 37 until use and to hold the adhesive in precise position until thermally bonded to its point of use. Tab ends 39' and 40' serve as aids in stripping tapes 39 and 40, respectively, from the adhesive charge 37.
    Type: Grant
    Filed: March 24, 1982
    Date of Patent: December 13, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Donald J. Progar
  • Patent number: 4065345
    Abstract: A process of preparing aromatic polyamide-acids for use as adhesives by reacting an aromatic dianhydride to an approximately equimolar amount of an aromatic diamine in a water or lower alkanol miscible ether solvent and wherein the polyamide-acids are converted to polyimides by heating to the temperature range of 200.degree. - 300.degree. C. and wherein the polyimides are thermally stable and insoluble in ethers and other organic solvents.
    Type: Grant
    Filed: October 22, 1976
    Date of Patent: December 27, 1977
    Assignee: The United States of America as represented by the United States National Aeronautics and Space Administration
    Inventors: Donald J. Progar, Vernon L. Bell, Terry L. St. Clair