Phosphorescent materials.

摘要

An organic phosphor which is a solid insoluble in water and organic solvents and which may be used in a phosphorescent printing ink or a paper coating composition comprises molecules of at least one phosphorescent activator held within a matrix of a condensation resin that does not itself absorb ultraviolet or visible radiation at the excitation and emission frequencies of the phosphorescence activator(s). The phosphorescence activator(s) is/are a compound or mixtures of compounds of the general formula (A)m - Ar - CO - X (I) wherein Ar denotes a fused ring polycyclic aromatic group; m is zero or an integer of from 1 up to the maximum number of ring positions available for substitutuion; X denotes an alkyl group or a group of the formula (A)m-Ar- or (B)n phi - wherein phi is a phenyl group and n is zero or an integer of from 1 to 5; and A and B represent ring substituents, or an acid addition salt thereof when said compound is basic.