Patents by Inventor Robert J. Kassal

Robert J. Kassal 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).

  • Molded parts used for photographic sensitive materials and resin compositions used to make thereof
    Patent number: 5866671
    Abstract: A novel resin composition for use in applications requiring low formaldehyde concentration levels. The novel composition comprising a stabilized polyacetal polymer with capped end groups is characterized by the concentration of formaldehyde generated from a formed object of the said composition in a closed environment being less than 20 ppm.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: February 2, 1999
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Kenichi Shinohara, Robert J. Kassal, Osamu Suzuki, Takashi Yoneyama
  • Polyacetal compositions for use in wear applications
    Patent number: 5559180
    Abstract: A polyacetal composition is provided for use in plastic-plastic wear applications, said composition containing about 85 to 99 weight percent polyacetal, about 0 to 5 weight percent polytetrafluoroethylene fibers, about 0.5 to 5 weight percent ethylene methyl acrylate copolymer, and about 0.5 to 5 weight percent of at least one lubricant. The compositions are particularly useful in forming shaped articles for use especially in conveyor chain applications and gear applications.
    Type: Grant
    Filed: April 3, 1995
    Date of Patent: September 24, 1996
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Tatsuhiro Takahashi, Edmund A. Flexman, Robert J. Kassal
  • Polyarylate molding compositions
    Patent number: 4902747
    Abstract: In the instant invention, improved blow moldable polyarylate compositions which yield molded objects having substantially uniform wall thickness throughout are provided by the addition of a small amount of a fibrillatable fluoropolymer resin.
    Type: Grant
    Filed: December 14, 1987
    Date of Patent: February 20, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert J. Kassal, Pallatheri M. Subramanian
  • Melt-fusible co-polyimide from diamine mixture
    Patent number: 4725642
    Abstract: Melt-fusible copolyimides based on pyromellitic anhydride and two defined classes of aromatic diamines, at least one diamine of each class being incorporated into the polyimide, each diamine class being present in an amount of 10-90 mole percent of the total diamine content (100 mole percent), melt below about 400.degree. C. and can be fabricated into articles, or can be applied to either fibrous or nonfibrous substrates to make prepregs, tapes, etc., which then are shaped into final articles, such as printed circuit boards or aircraft panels.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: February 16, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Thomas P. Gannett, Robert J. Kassal, Rolland S. Ro, Julius Uradnisheck
  • Melt-fusible polyimides
    Patent number: 4485140
    Abstract: Melt-fusible polyimides based on pyromellitic dianhydride and 2,2-bis[3,5-dichloro-4-(4-aminophenoxy)phenyl]propane, alone or in combination with other defined diamines, are useful in making low-void composites and thermoplastic tapes, which can be fabricated into articles such as, for example, aircraft and autobody panels, printed circuit boards, etc.
    Type: Grant
    Filed: January 27, 1984
    Date of Patent: November 27, 1984
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Thomas P. Gannett, Hugh H. Gibbs, Robert J. Kassal
  • Elastomer modified unsaturated molding compositions
    Patent number: 4161471
    Abstract: Filled unsaturated ester bulk molding, sheet molding, premix or mat molding compositions are modified with elastomer to give finished products with both improved impact strength and improved surface characteristics. The elastomeric modifier is selected from the group consisting of chloroprene polymers and hydrocarbon polymers such as ethylene/propylene di-, ter-, or tetrapolymers.
    Type: Grant
    Filed: April 13, 1978
    Date of Patent: July 17, 1979
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert J. Kassal