A chromene compound represented by the following formula (1),
wherein,
"A" is an annulated ring, R1 and R2 are hydrogen atoms, hydroxyl groups or the like groups,
R3, R4, R5 and R6 are substituents such as hydroxyl groups or the like groups,
"a" and "b" are, respectively, integers of 0 to 4, and
"c" and "d" are, respectively, integers of 0 to 5. The chromene compound is a photochromic compound developing a color of a neutral tint, and has a high color density per a unit amount.
由下式(1)代表的色烯化合物、
其中
A "为环状环,R1 和 R2 为氢原子、羟基或类似基团、
R3、R4、R5 和 R6 是取代基,如羟基或类似基团、
"a "和 "b "分别是 0 至 4 的整数,以及
c "和 "d "分别为 0 至 5 的整数。色烯化合物是一种显中性色调的光致变色化合物,单位用量的颜色密度高。