| 摘要 |
A chromene compound which contains a skeleton represented by the following formula (1) and has high color optical density at the time of exposure, double peak characteristic, little initial coloration, a practical fading speed and durability.
(wherein R 1 is an electron donor group having a Hammett constant of less than 0, the ring including X is a hetero ring formed together with the 7-position and 8-position carbon atoms, and X is an oxygen atom, sulfur atom or group represented by =NR 2 directly bonded to the 7-position carbon atom.)
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