Nara Institute of Science and Technology

Takuya Nakajima

Tsuyoshi Kawai

Shigekazu Kawai

The present invention provides a photochromic compound that is colored when irradiated with visible light and quickly faded when set in a dark place. The photochromic compound according to the present invention is expressed by the following general formula (I): where each of A, Aand Ais a five-member rings forming a 6&#x3c0;-electron system, the three rings being identical, partially identical or totally different from each other, and each ring may have a substituent; Band Bare functional groups, each having an atomic number of five or larger, including a ring compound, and bonded to the 2-carbon of each of Aand A, respectively; and R, Rand Rare substituents identical to or different from each other. This compound is highly colorable and durable even when it is dispersed into plastic macromolecular materials. Therefore, it is suitable as a dye material for sunglasses or similar products.

Growing community of inventors

Ikoma, Japan

Takuya Nakajima