| 摘要 |
PURPOSE:To provide excellent conservation properties of a heat sensitive recording material having high sensitivity and high whiteness index and to prevent variation in color-tone after conservation by incorporating substances of predetermined compositions as basic dye, developer and additive in a heat sensitive recording layer. CONSTITUTION:Substance represented by a formula [I] colorless or pale basic leuco dye, developer represented by a formula [II], and compound represented by a formula [III] are used in combination. Normally, 0.5-3 pts.wt. of developer represented by the formula [II] is used to 1 pts.wt. of coloring basic dye represented by the formula [I], and the substance represented by a formula [III] of 0.1-20 pts.wt. is added to 1 pts.wt. of the developer. It is desirable to add 1-2 pts.wt. of developer to 1 pts.wt. of the basic dye or 0.2-5 pts.wt. of substance represented by the formula [II] to 1-2 pts.wt. of developer. Thus, its conservation properties are greatly improved, and color-one after conservation is not varied as black. |
