Patents Assigned to Schwan-Bleistift-Fabrik Schwanhausser & Company
  • Ink with ester additive providing easy wipe off of ink markings
    Patent number: 4097289
    Abstract: The invention relates to an ink capable of producing writing or marking on a non-absorbent or impermeable surface, which can easily be wiped off. The disadvantages inherent in the known inks are overcome by adding ester compounds of a certain composition to the ink.
    Type: Grant
    Filed: March 15, 1976
    Date of Patent: June 27, 1978
    Assignee: Schwan-Bleistift-Fabrik Schwanhausser & Company
    Inventors: Hans Joachim Hofmann, Axel Jankewitz