| 摘要 |
PURPOSE:To enhance storage stability and high speed recording properties by using a compd. represented by a predetermined formula as the developer of a leuco dye. CONSTITUTION:As a developer forming a thermal color forming layer on a support along with a leuco dye, a compd. represented by formula (wherein R is an alkyl group, an aralkyl group or an aryl group and the alkyl group may have an alkoxy group, an acyl group, an acyloxy group, a halogen atom or a nitro group and the aromatic ring of the aralkyl and aryl groups may have an alkyl group, an alkoxy group, an acyl group, an acyloxy group, a halogen atom or a nitro group) is used. Further, sensitivity can be enhanced by providing an intermediate layer containing plastic spherical fine hollow particles with a mean particle size of 2-10mum and a percentage of hollowness of about 90% or more between the support and the color forming layer. |
