Urea stabilizers for thermal dye transfer materials

摘要

The present invention relates to a thermal donor comprising a dye mixture and a urea light-stabilizing compound, wherein the light-stabilizing compound is represented by structure I: wherein: R₁, R₂ and R₃ represent a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, aralkyl group, aryl group or heterocyclic group, provided that at least one of R₁, R₂, and/or R₃ is a hydrogen atom; R₄-R₈ represent a hydrogen atom, hydroxyl group, alkyl group, cycloalkyl group, alkenyl group, aralkyl group, aryl group, heterocyclic group, aryloxy group, or alkoxy group; and R₃ forms a heterocyclic ring with either R₄ or R₈, and an imaging system comprising a donor sheet having a layer containing a dye and an image receiving sheet having a dye receiving layer, wherein either the donor sheet or the image receiving sheet comprises a dye mixture and a urea light-stabilizing compound of structure I.