JPS54104352A - Electro-thermal heat sensitive recording sheet - Google Patents

Abstract

PURPOSE: To prevent pressure coloring and to enhance image contrast, by using a specified ring-opened lactone compound as a color forming dye.

CONSTITUTION: A conductive ZnO, a color forming dye of formula I, a color developer, and a binder are dispersed to form a color forming fluid, and this is coated and dried on a conductive layer provided on a substrate to form a color forming layer, permitting organic solvent resistance, color forming performance, and sunlight fading resistance to be improved to a large extent, and long period storage stability to be ensured. In formula I, R₁ and R₂ are H, lower alkyl, substitutable aralkyl or phenyl, cyanoethyl, or the like; or R₁ and R₂ combine to form formulae II, III, or IV; R₃ and R₄ are H, lower alkyl, aralkyl, amyl, or phenyl, but at least one of them is H; X₁, X₂, and X₃ are H, lower alkyl, lower alkoxy, halogen, halogenomethyl, nitro, or substitutable amino; X₄WX₇ are H, lower alkyl, lower alkoxy, or halogen; and X₅ and X₆ may like to each other to form a naphthalene ring together with the benzence ring.

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