| abstract |
Fluorescent pigment compounds comprising aryl-ureido benzoxazinone compounds of the general formula (I): wherein R1 is an substituted or unsubstituted aryl group, R2 and R3 are each independently selected from an H atom, an alkyl group, an alkoxy group, an alkylcarboxy group and a halogen atom, X is a carbon or sulfur atom and n is an integer of I or more. Many of the compounds of this class produce a yellow, generally deep yellow, emission at wavelengths of about 560 to about 585 nm when excited by an appropriate UV source. These compounds produce fluorescence making them useful as fluorescent pigments, those compounds providing emission wavelengths within the range of from about 560 to about 585 or higher when excited by a UV source are particularly useful. Those compounds having this emission spectra for the compounds makes these compounds particularly useful as pigments in security applications, particularly as pigments for use in security inks and fibers. |