CHROMENE COMPOUND

摘要

A novel photochromic compound which develops a color of a neutral tint (double peak characteristic) and has high color optical density, high fading speed and excellent durability. Like a compound represented by the following formula (20), the photochromic compound having a group (methylthio group in the following formula 20) which has a sulfur atom bonded to the 7-position carbon atom is a photochromic compound having high color optical density, high fading speed and excellent durability.