| 摘要 |
PURPOSE:To improve a sensitization effect and light resistance by using a mixture of a specific phthalide compound and a specific fluorane compound as a dye precursor, a specific sulfonic compound as a color developer, and a specific oxalic compound as a sensitizer. CONSTITUTION:As a colorless or light-colored dye precursor, a phthalide compound shown by a formula I and a fluorane compound shown by a formula II are used. As a color developer, a sulfonic compound shown by a formula III is used. As a sensitizer, a dibasic ester compound shown by a formula IV is used. These phthalide compound and the fluorane compound are preferably mixed in the mole ratio of 8:2-1:9. As the aforseaid sulfonic compound as a color developer for a mixed dye, bis(3-allyl-4-hydroxyphenyl) sulfone is more preferably used. This sulfonic compound is used in the ratio of 0.1-10 parts by weight per 1 part of dye precursor. As the sensitizer, the dibasic ester compound is preferably used. For example, di(p-chlorobenzyl) oxalate is more preferable. This sensitizer is used in the ratio of 0.1-10 parts by weight per 1 part of dye precursor. |
