Patents by Inventor Wilfried Voigt

Wilfried Voigt 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).

  • Tantalum (V) nitride pigment, process for producing it and its use
    Patent number: 6294009
    Abstract: The invention relates to tantalum (V) nitride pigments with improved color values compared with predisclosed products, a process for producing such pigments and their use. According to the invention, pigments having an a* color value in the CIE Lab system of equal to/greater than 45, in particular equal to/greater than 50, are obtainable by after-treating a tantalum (V) nitride produced in a known manner in a salt melt at 100 to 600° C., in particular 300 to 500° C., in the course of 1 to 100 minutes, in particular 5 to 60 minutes. Preferably, the after treatment is carried out in an alkali-metal nitrate melt. The pigments can be used to color plastics and paints, and also enamel, glass and porcelain decorations.
    Type: Grant
    Filed: December 2, 1999
    Date of Patent: September 25, 2001
    Assignee: dmc
    Inventors: Hans-Peter Letschert, Wilfried Voigt
  • Tantalum (V) nitride pigments, process for the production thereof and use thereof
    Patent number: 6235103
    Abstract: Tantalum(V) oxide may be nitrided with ammonia at 700 to 1250° C. to yield tantalum(V) nitride. According to the invention, nitriding and consequently pigment quality are improved by adding at least one pulverulent oxide from the series SiO2, GeO2, SnO2, TiO2, ZrO2 and HfO2 or a pulverulent precursor of such an oxide in a quantity of at least 0.1 wt. %, calculated as oxide, to the tantalum(V) oxide to be nitrided and then nitriding the powder mixture.
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: May 22, 2001
    Assignee: Cerdec Aktiengesellschaft Keramische Farben
    Inventors: Hans-Peter Letschert, Wilfried Voigt