| abstract |
The color tone at the time of color development is intermediate, the color density is high, the color fading speed is fast, the durability is good, and as shown by the following formula, indeno (2,1-f) naphtho (1,2- b) Having a pyran structure as a basic skeleton, the carbon atom at the 6-position and / or 7-position is selected from a thiol group, alkylthio group, alkoxyalkylthio group, haloalkylthio group, cycloalkylthio group, arylthio group and heteroarylthio group A photochromic chromene compound having a sulfur-containing substituent. |