Patents by Inventor Ian M. Johnson

Ian M. Johnson 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: 4798861
    Abstract: The properties of water soluble or, especially water swellable polymer particles are improved by surface cross linking that is caused by providing a dispersion of gel polymer particles in an organic solvent, reacting the surfaces of these particles with dissolved cross linking agent and azeotropically distilling the dispersion.
    Type: Grant
    Filed: November 24, 1986
    Date of Patent: January 17, 1989
    Assignee: Allied Colloids Limited
    Inventors: Ian M. Johnson, Ian M. Moody, Peter Flesher
  • Patent number: 4585843
    Abstract: An exothermic gel polymerization process conducted in the presence of water is initiated at a low temperature, is held for most of the process at a higher temperature by including in the medium a particulate heat sink material, such as sodium sulphate decahydrate, that is substantially insoluble in the medium and which undergoes an endothermic phase change and is then allowed to rise to a higher temperature. Either as a result of the endothermic change, or as a result of a subsequent exothermic change, at the end of the process the heat sink material is again solid particulate material substantially insoluble in the medium and so the product is a dispersion of the material in a polymer gel. The polymer is water soluble.
    Type: Grant
    Filed: November 30, 1984
    Date of Patent: April 29, 1986
    Assignee: Allied Colloids, Ltd.
    Inventors: Peter Flesher, David Farrar, Ian M. Johnson
  • Patent number: 4259023
    Abstract: An incompletely miscible liquid mixture, e.g. a suspension polymerization mixture, is mixed by flowing through a rotating substantially horizontal tube that is incompletely filled with the mixture, so as to form pairs of vortices each with its axis transverse to the axis of the tube. The apparatus comprises the tube, that must be free of internal means for agitating the liquid within the tube, means for rotating the tube and means for feeding the liquid mixture to and through the tube.
    Type: Grant
    Filed: May 21, 1979
    Date of Patent: March 31, 1981
    Assignee: Allied Colloids Limited
    Inventors: Peter Flesher, Ian M. Johnson
  • Patent number: 4256660
    Abstract: A compound of the formulaCH.sub.2 .dbd.CRCONHXNHCOCH.sub.2 CH.sub.2 SO.sub.3 Mwhere R is hydrogen or methyl, X is CH.sub.2 or --CH.sub.2 OCH.sub.2 -- and M is H or a water soluble cation is made by reacting N-methylolacrylamide or N-methylolmethacrylamide with sulphonated N-methylolacrylamide.
    Type: Grant
    Filed: May 28, 1980
    Date of Patent: March 17, 1981
    Assignee: Allied Colloids Limited
    Inventors: Peter Flesher, Ian M. Johnson