US Patent 7276088 - CNT hair colorant

http://www.freepatentsonline.com/7276088.html

The use of nanostructured material in general is not new to cosmetics but this patent from DuPont specifically focuses on the use of carbon nanotubes as an ingredient of an improved hair colorant. The nanotubes are used as a black pigment with improved smoothing and volumizing effects. Claim 1 recites:

1. A method for coloring hair, eyebrows or eyelashes comprising the sequential steps of: a) applying a polymer composition to hair, eyebrows or eyelashes to form a first polymer treated layer; b) contacting the first polymer treated layer of step (a) with a chemically functionalized carbon nanotube to form a first colorant layer; c) applying a polymer composition to the first colorant layer of step (b) to form a second polymer treated layer; d) contacting the second polymer treated layer of step c) with a chemically functionalized carbon nanotube to form a second colorant layer; and e) optionally, repeating steps (a)-(d) one or more times.