| 摘要 |
PURPOSE:To improve color-developing property and stock durability of a fixing type thermal recording medium consisting mainly of diazonium salt, coupler, color-developing assistant and organic basic compounds, by using specified aryl ester derivatives as a color-developing assistant. CONSTITUTION:Using aryl esterderivatives expressed by formula I (where R represents C1-8C alkyl group, alkylene group, alkoxy group, benzyloxy group, etc., Ar an aromatic ring such as a benzene ring, naphthalene ring etc., and n an integer), of a melting point of 40-160 deg.C and difficultly soluble or insoluble in water and a mixture of diazonium salt, coupler compound and color-developing assistant of the following mixing ratio is used: 1:(0.1-10):(0.1-20) (in weight ratio). As a color-developing agent, known organic basic compounds may be used, and guanidine derivatives represented by formula II or III (where R1-R5 represent hydrogen, alkyl, amino, etc., R6 lower alkylene, phenylene, etc.) are preferable. |
