ALEXANDRIA, Va., Dec. 23 -- United States Patent no. 12,503,543, issued on Dec. 23, was assigned to Transitions Optical Ltd. (Tuam, Ireland).
"Curable photochromic polycarbodiimide compositions" was invented by Ramaiahgari Reddy (Murrysville, Pa.), Brad S. Veldkamp (Allison Park, Pa.) and Anil Kumar (Murrysville, Pa.).
According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention relates to curable photochromic compositions which include a polycarbodiimide, an at least di-functional first carboxylic acid functional material having at least two carboxylic acid groups, an optional second carboxylic acid functional material having at least three carboxylic acid groups, a photochromic compound, and an aprot...