Patents by Inventor David R. Clark

David R. Clark 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).

  • Treatment of aqueous systems
    Patent number: 4192744
    Abstract: Aqueous compositions containing compounds having the formula: ##STR1## wherein R is a straight- or branched alkyl residue containing 11 to 17 carbon atoms and X and Y are the same or different and each is an alkali metal, an alkaline earth metal, ammonium, an amine radical or hydrogen for selectively flocculating iron ions.
    Type: Grant
    Filed: October 28, 1977
    Date of Patent: March 11, 1980
    Assignee: Ciba-Geigy Corporation
    Inventors: David R. Clark, Alan Marshall, Michael A. Finan
  • Additives for water-based functional fluids
    Patent number: 4177155
    Abstract: Selected N-aminomethyl-triazoles and imidazoles are prepared by the Mannich reaction on benzotriazoles or benzimidazoles with formaldehyde and primary or secondary amines. The products consist mainly of the 1-isomers. The compounds are metal passivators and are used as additives for water-based functional fluids being in contact with metals. These compounds with polar substituents on the amino-group are especially useful in water-based fluids such as anti-freeze or metal-working fluids.
    Type: Grant
    Filed: May 19, 1977
    Date of Patent: December 4, 1979
    Assignee: Ciba-Geigy Corporation
    Inventors: Alan F. Popplewell, deceased, David R. Clark