| 摘要 |
PURPOSE:To greatly lessen the fading of color pictures recorded by heat and moisture as well as disappearance of pictures by plasticizer or oil, and also to improve the thermal respondence of a thermal recording material by using a specific 2,3-dihydroxy compound as all or a part of developers to be used. CONSTITUTION:In a thermal recording material utilizing the chromogenic reaction between a leuco dye and a developer, a 2,3-dihydroxynaphthalene compound of the formula I as the main component of developer, where R1 is H or a C1-C3 alkyl or hydroxyalkyl, R2 is H, a C1-C3 alkyl or hydroxyalkyl, amino, or the formula II [where, R3 is an alkyl, halogenated alkyl, halogen or alkoxy, (n) is an integer of 1-3, and in case of plural R3, R3 may be same or different], is used. Besides the compound of the formula I, developers of phenolic substances, inorganic or organic substances or their derivatives may be used. The preferred amount of the developer to be used is 1-10pts.wt. on the basis of 1pt.wt. leuco dye in general, and that of the developer of the formula I is 20wt% or more of all the developers. |
