Patent ID: 7976739

Claim:
A chromene compound represented by the following formula (1), wherein, “A” is an annulated ring, R 1 and R 2 are, respectively, hydrogen atoms, hydroxyl groups, alkyl groups, cycloalkyl groups, alkoxy groups, aralkyl groups, aralkoxy groups or aryl groups, R 1 and R 2 may be linked to each other to form a ring, and R 1 and R 2 together may form a carbonyl group with a carbon atom to which these groups are bonded, R 3 , R 4 , R 5 and R 6 are, respectively, hydroxyl groups, alkyl groups, cycloalkyl groups, alkoxy groups, aralkyl groups, aralkoxy groups, aryl groups, amino groups, cyano groups, nitro groups, halogen atoms, halogenoalkyl groups, halogenoalkoxy groups, or heterocyclic groups having a nitrogen atom as a hetero atom and being bonded through a bond at the nitrogen atom as a bonding hand and, when R 3 s are present in a plural number, two R 3 s may be coupled together to form a ring, “a” and “b” are, respectively, integers of 0 to 4, and “c” and “d” are, respectively, integers of 0 to 5.