Patents by Inventor Trygve Maldal

Trygve Maldal 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).

  • Surfactant, process for its production and use
    Patent number: 5523470
    Abstract: A new class of surfactants exhibits properties, which make the surfactants suitable for use in surfactant flooding for enhanced oil recovery. The surfactants have the formulaXA.sub.r ORSO.sub.3.sup.- M.sup.+ (I)where R is a hydrocarbon or hydroxyl-substituted hydrocarbon group with 2-6 carbon atoms; A is an oxyalkylene group having 2-4 carbon atoms; r is a number from 0-10, preferably 0-5 and most preferably 1-4; X is an hydroxyl group or hydroxyl and ether group containing hydrophobic group, which comprises 2-6, preferably 2-4 end groups containing 3-22 carbon atoms; and M is a cation, preferably a monovalent cation; or a C.sub.1-4 -alkyl ether thereof. A method for the manufacture of the surfactants are also enclosed.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: June 4, 1996
    Assignees: Berol Nobel AB, Den norske stats oljeselskap a.s.
    Inventors: Leif Karlsson, Per-Erik Hellberg, Lena Eriksson, Stig Svennberg, Eimund Gilje, Siri Espedal, Trygve Maldal