ALEXANDRIA, Va., Sept. 30 -- United States Patent no. 12,428,390, issued on Sept. 30, was assigned to TOKUYAMA Corp. (Yamaguchi, Japan).
"Chromene compound and photochromic optical article" was invented by Masayuki Miyazaki (Shunan, Japan), Junji Takenaka (Shunan, Japan) and Junji Momoda (Shunan, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A chromene compound which can exhibit excellent photochromic properties. The chromene compound is represented by the following formula (1). In the formula, at least one of R1 or R2 represents the group having the radical-polymerizable group, wherein the group having a radical-polymerizable group is represented by the following formula (2) (wherein R10 represents a...