Patents by Inventor Hans Schlaepfer

Hans Schlaepfer 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 and product of optical brightening with quaternized benzofuranyl-benzimidazoles
    Patent number: 4009994
    Abstract: The invention relates to new quaternized benzofuranyl-benzimidazole derivatives which can be prepared by known methods. Said compounds are useful as optical brighteners for organic material.
    Type: Grant
    Filed: October 2, 1975
    Date of Patent: March 1, 1977
    Assignee: Ciba-Geigy Corporation
    Inventor: Hans Schlaepfer
  • Quaternised benzofuranyl-benzimidazoles
    Patent number: 3940417
    Abstract: The invention relates to new quaternised benzofuranyl-benzimidazole derivatives which can be prepared by known methods. Said compounds are useful as optical brighteners for organic material.
    Type: Grant
    Filed: August 22, 1974
    Date of Patent: February 24, 1976
    Assignee: Ciba-Geigy Corporation
    Inventor: Hans Schlaepfer