The Development of New Generation Color Couplers and Image Stabilizers Introduced in Konica Color Papers Over the Last Decade

Abstract

Over the last ten years, we have succeeded in the development of new generation color couplers, introduced in Konica Color papers. In 1984, the coupler, 2, 5-di-acylaminophenol, assured greater dye image stability under dark storage conditions in Konica Color PC Paper Type SR (Century Print). By 1991, new generation color couplers and image stabilizers were presented in Konica Color QA Paper Type A5 (QAA5) to provide excellent color reproduction and outstanding dye image stability. The dyes formed from these new generation couplers have superior spectral absorption, reducing the unwanted absorption, while maintaining dye image stability in dark storage conditions.
Image stabilizing technology improves the light fasteness of a dye image by quenching the excited singlet oxygen and scavenging the radical species induced by light absorption. Of particular note is the synergistic light stabilizing effect, in combined usage with the singlet oxygen quencher and the radical scavenger, used to improve the light stability of magenta dye. This magenta dye, consequently, is formed from a new class magenta coupler, pyrazolotriazole. This new magenta coupler also provides the merit of reducing yellow stain.