Patents by Inventor Robert T. Iwamasa

Robert T. Iwamasa 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: 5569686
    Abstract: The adhesive of the present invention includes latexes with an adhesion promoter which is preferably polyamidoamine. The addition of the polyamidoamine improves the adhesive strength between substrates such as between two plastic films or between a plastic film and paperboard. The present invention also provides for an adhesive prepared from a latex which is neutralized with a particular base and a hydrophobic polyamidoamine having particular amine values and viscosity whereby the strength of the adhesive bond is increased in humid conditions. The present invention also provides for adhesives primarily for use in laminate structures which are exposed to highly humid conditions. The adhesive is a polymeric latex based system to which a polymeric adhesion promoter like polyamidoamine and an epoxy emulsion are added. The adhesive retains bond strength when exposed to humidity.
    Type: Grant
    Filed: March 19, 1990
    Date of Patent: October 29, 1996
    Assignee: The Dow Chemical Company
    Inventors: Ashok C. Makati, Charles S. Kan, Robert T. Iwamasa, Do I. Lee
  • Patent number: 4968740
    Abstract: A latex based adhesive comprising a first component (adhesive component) comprising an interpolymer of at least one hard monomer, at least one soft monomer, and optionally a copolymerizable carboxylic acid comonomer having a Tg of from about -70.degree. C. to about -5.degree. C. and a second polymeric component (tackifier component) that is compatible with the adhesive component having a molecular weight less than 5,000 and a Tg from about -10.degree. C. to about 50.degree. C., both the adhesive component and tackifier component having been separately prepared by emulsion polymerization techniques.
    Type: Grant
    Filed: January 20, 1987
    Date of Patent: November 6, 1990
    Assignee: The Dow Chemical Company
    Inventors: Ashok C. Makati, Do I. Lee, Bettye W. Greene, Robert T. Iwamasa