Patents by Inventor John F. Firth

John F. Firth 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: 4713264
    Abstract: Process of forming prepasted wallcovering comprising a porous surface that carries a dry coating of polymer particles that become adhesive when wetted by water is made by applying to the surface a dispersion of the particles in a non-aqueous liquid that is stabilized by a polymeric stabilizer and then evaporating the non-aqueous liquid. A dried residue of the dispersion must not form a coherent film and should have a softening point substantially independent of the softening point of the polymeric stabilizer. The polymeric stabilizer is preferably an oil. The non-aqueous liquid is preferably relatively non-volatile.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: December 15, 1987
    Assignee: Allied Colloids Limited
    Inventors: John B. Clarke, John F. Firth, John R. Walker
  • Patent number: 4639395
    Abstract: A wallcovering comprises a substrate carrying a water-moistenable coating formed of at least two layers. The layer adjacent to the substrate generally comprises unswollen particles of an anionic polymer that is substantially non-swellable in water and that is swellable in aqueous alkali and the upper layer contains an alkali which on contact with water forms an alkaline solution which swells the anionic polymer and a water soluble cationic polymer. The anionic polymer generally comprises beads of cross-linked copolymers of lower alkyl acrylates and methacrylic acid having a molecular weight of about 5 million. Processes for producing the wallcoverings comprise coating the substrate separately with an aqueous dispersion of the anionic polymer and an aqueous solution containing both the cationic polymer and the alkaline material to give at least two separate layers.
    Type: Grant
    Filed: March 14, 1985
    Date of Patent: January 27, 1987
    Assignee: Allied Colloids Limited
    Inventors: John B. Clarke, John F. Firth
  • Patent number: 4476190
    Abstract: The adhesive coating of a water wettable prepasted wallcovering is formed of a blend of water insoluble but water swellable anionic polymer particles and water insoluble but water swellable cationic polymer particles. The coating may be applied from a dispersion of the particles in volatile organic liquid.
    Type: Grant
    Filed: October 8, 1982
    Date of Patent: October 9, 1984
    Assignee: Allied Colloids Limited
    Inventors: John B. Clarke, John F. Firth