The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 2001
Filed:
Dec. 02, 1999
Hans-Peter Letschert, Hanau, DE;
Wilfried Voigt, Rodenbach, DE;
dmc, Frankfurt am Main, DE;
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.