Patents Assigned to Schwan-STABILO Cosmetics GmbH & Co. KG
  • Method for increasing the tensile, breaking and flexural strength of colored leads and colored pencils containing the same
    Patent number: 6830610
    Abstract: A method for increasing the tensile, breaking and flexural strength of coloured leads. The method is characterized in that 1 to 50 percent by weight alkyl and/or hydroxyalkyl cellulose which are soluble in organic solvents and whose alkyl radicals can be straight-chained or branched are added to the lead substance. The invention also relates to coloured pencils containing said coloured leads.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: December 14, 2004
    Assignee: Schwan-Stabilo Cosmetics GmbH & Co. KG
    Inventors: Werner Bruchert, Christian Sprogar, Willy Weiss