Patents by Inventor John A. Gascoigne

John A. Gascoigne 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: 5017268
    Abstract: A filler composition that is suitable for use in the manufacture of paper, board, wet-laid non-wovens or other fibrous sheet materials comprises (preferably flocculated) filler particles (e.g. mineral fillers such as clay, talc or calcium carbonate) attached to fibres (e.g. synthetic organic fibres such as polyester or aramid fibres) by means of a coupling agent. These fibres generally have an average fibre length of 4 mm or more. Suitable coupling agents include oligomeric and other polymeric materials such as modified starch, cellulose ethers and derivatives thereof, modified natural gums, ketene dimers or poly(vinyl alcohol). Colloidal silica or colloidal bentonite clay may also be included. The filler composition is preferably added to the stock before the latter reaches the flowbox of the sheet-making machine. The invention allows high levels of filler to be achieved while maintaining satisfactory strength properties, in particular tear strength, in the sheet.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: May 21, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Barbara M. Clitherow, Trevor W. R. Dean, John A. Gascoigne, Bernhard E. Van Issum