Patent ID: RE41616

Claim:
A method for identifying a polycarbonate polymer, comprising providing in the a polycarbonate polymer at least one and a tagging material wherein the tagging material comprises at least one organic fluorophore dye, or at least one inorganic fluorophore, or at least one organometallic fluorophore, or at least one semi-conducting luminescent nanoparticle, or a combination thereof, wherein the tagging material has a temperature stability of at least about 350° C. and is present in a sufficient quantity such that the tagging material is detectible via a spectrofluorometer at an excitation wavelength in a range between about 100 nanometers and about 1100 546 nanometers , and wherein the tagging material is uniformly dispersed throughout the polycarbonate polymer or dispersed in a portion of the polycarbonate polymer by means of an extruder or injection molder during melt polymerization of the polycarbonate polymer whereby a sample of the polymer composition can be identified or distinguished from samples of other polymers containing no or different tagging materials, and identifying the polymer based on the detected tagging material .