Reactive, Fluorescent Coumarin Dyes for Making Thermosets Visible under Ultraviolet Light

Case ID:

The invention describes a novel use for coumarin dyes to make thermosets visible under only certain conditions, which provides a means of identifying whether or not a reaction has occurred. In addition, this technology is capable of allowing the user to hide the use of an epoxy unless there is a need to see it.


Dyes are most often used to color plastics. This color can also act as an indicator to identify when polymerization has been completed or as an aesthetic additive. This technology leverages a small amount of coumarin to create a coloration within a thermoset that cannot be removed, mechanically weakened, or extracted, while maintaining the ability to both conceal the use of an epoxy and signal the completion of polymerization. 



  • Epoxy additive
  • Reaction indicator


  • Provides selective visibility
  • Requires only a minimal amount of coumarin so as not to interfere with the reaction
  • Extraction resistant
  • Does not interfere with polymerization
  • Results in a coloration that cannot be removed, mechanically weakened, or extracted
Patent Information:
Contact For More Information:
Jace Langen
Licensing Manager
The University of Arizona
Lead Inventor(s):
Douglas Loy
Peter Mcfadden