Patents by Inventor Lars Petander

Lars Petander 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).

  • Process for preparing a cationically modified (meth)acrylamide polymer and use of the polymer
    Patent number: 6387998
    Abstract: The invention relates to a process for preparing a cationically modified (meth)acrylamide polymer by the Mannich reaction. There is prepared in advance a stable aldehyde-secondary amine adduct, which is obtained as a reaction product of an aqueous solution of the secondary amine and an aqueous solution of the aldehyde, and which, after the formation of the adduct, is stabilized to endure storage, by lowering the pH of the mixture of 7 or below and/or by adding methanol, and the adduct thus prepared is added to an aqueous solution of the (meth)acrylamide polymer and the pH is adjusted to an alkaline level, whereupon modification occurs. The invention also relates to the use of the modified (meth)acrylamide polymer as a flocculation, retention or dewatering agent.
    Type: Grant
    Filed: April 13, 2000
    Date of Patent: May 14, 2002
    Assignee: Kemira Chemicals Oy
    Inventors: Jonni Ahlgren, Lars Petander, Jussi Nikkarinen
  • Paper-making method and a combination of ingredients to be used in it
    Patent number: 4756801
    Abstract: In a paper-making method cellulose is suspended in water and the obtained pulp suspension is dewatered in order to form a fiber web or a fiber sheet, water being removed from a pulp suspension which contains an organic polymer and an inorganic oligomeric Ti, Zr, Sn or B compound.
    Type: Grant
    Filed: October 24, 1986
    Date of Patent: July 12, 1988
    Assignee: Kemira Oy
    Inventors: Olli J. Jokinen, Lars Petander, Pirkko J. Virta