Highly fluorescent markers for fluids or articles
View Patent ↗The present invention provides highly fluorescent markers, made from a reactive polymer and an isocyanate, that fluoresce in the ultraviolet or near infrared region without being visible to the human eye at low concentrations in the fluid or article being marked. The molecular weight and fluorescence emission wavelength of these highly fluorescent marker compounds can be adjusted to provide a multitude of markers with unique fluorescence signatures.
1. A process for marking one of a fluid, a fluid blend or a solid composition, the process comprising adding to the one of a fluid, a fluid blend or a solid at least one fluorophore-containing reactive polymer, said reactive polymer being prepared from monomers having no more than one 1,2-epoxide group per molecule, having a molecular weight in the range of 250 to 40,000 Da, and having from 1 to 8 active hydrogen atoms per molecule of reactive polymer, wherein said reactive polymer is chosen from polyesters and polyether polyols, and said reactive polymer is free of polyamines, wherein the fluorophore-containing reactive polymer emits fluorescence in the ultraviolet (UV), visible, or near infrared (IR) region.
2. The process according to claim 1 , wherein the fluorophore of the fluorophore-containing reactive polymer is Bisphenol A.
3. The process according to claim 1 , wherein the polymer has a molecular weight of about 500 to about 20,000 Da.
4. The process according to claim 1 , wherein the polymer has an excitation wavelength to induce fluorescence of greater than about 210 nm and an emission wavelength of greater than about 290 nm.
5. The process according to claim 1 , wherein the fluid blend is chosen from diesel fuel, gasoline and heating oil.
6. The process of claim 1 , wherein said polyether polyols are prepared from one or more alkylene oxides comprising ethylene oxide, propylene oxide, butylene oxides, and combinations thereof.
7. The process according to claim 1 , wherein said fluorophore-containing reactive polymer is present in the range of from 1 ppb to 100 ppm, based on the total weight of the fluid, the fluid blend or the solid.