| 摘要 |
PROBLEM TO BE SOLVED: To improve the density, hue, and shelf stability of recording images by the use of a fluoran compound expressed by a specific formula and a fluoran compound expressed by another specific formula as a coloring agent of pressure sensitive and thermal recording material. SOLUTION: Contained as electron donative coloring agents are at least one kind of fluoran compounds expressed by formula I, and at least one kind of fluoran compounds expressed by formula II. In the formula I, R<1> , R<2> show respectively a 1-5C alkyl group, R<3> , R<4> in the formula II, show respectively an alkyl group, a cycloalkyl group, an alkoxialkyl group, or an aryl group, and an N-containing heterocycle can be formed in combination of R<3> and R<4> . R<5> , R<6> show respectively an alkyl group or a halogen atom. In order to enhance its ground whiteness, coloring sensitivity, and image preservability comprehensively, the rate of use is made preferably of the order of (a compound of formula I):(a compound of formula II)=98:2 to 65:35 by a weight ratio. |
