摘要 |
<p>Disclosed herein is an imaging medium comprising a substrate carrying a color-change layer which develops color upon heating. The addition of a novel block copolymer surfactant containing ethylene oxide (EO) and propylene oxide (PO) into the leuco dye dispersion prevents color pre-formation during the dispersion preparation stage, and in the final coating fluid in the presence of developers and acids. The pluronic may complex the acid developer as well as the final image dye.</p> |