| 摘要 |
PURPOSE:To make the title phthalide compound easily soluble in a color coupler solvent and to contrive to improve the durability of a colored dye by containing a specific phthalide compound as a coloring substance. CONSTITUTION:Phthalide compound indicated by the formula is contained as a coloring substance. In the formula, R indicates C1-C8 straight chain or branch alkyl group or hydrogen atom and R1 represents C1-C4 straight chain or branch alkyl group. This phthalide compound is a stable colorless or slightly colored solid in the air and easily soluble in alkylated phthalene used as a color coupler solvent in a pressure-sensitive copying paper and immediately forms a blue dye when it comes in contact with an acid substance, and this colored dye has an excellent light resistance. Especially, a colored picture obtained by salicylic acid derivative zinc salt is remarkably excellent in light resistance. |
