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US 9,469,717 B2Granted
Highly fluorescent markers for fluids or articles
AssigneeCovestro LLC
InventorGeorge G. Combs
Life of this patent
Estimating the term…
Abstract
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.
Claims7
A process for marking one of a fluid, a fluid blend or a solid composition, comprising adding to the one of a fluid, a fluid blend or a solid the reaction product of
- at least one non-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;
- and
- at least one unsubstituted or substituted aryl isocyanate,
- at an isocyanate index of about 100 or less,
- wherein the reaction product emits fluorescence in the ultraviolet (UV), visible or near infrared (IR) region.
2 more elements
Dependencies are inferred from the claim text.