ALEXANDRIA, Va., July 30 -- United States Patent no. 12,371,516, issued on July 29, was assigned to Bridgestone Corp. (Chuo-ku, Japan).

"Aged lanthanide-based catalyst systems and their use in the preparation of cis-1,4-polydienes" was invented by Joshua S. Dickstein (Copley, Ohio), Steven Luo (Akron, Ohio), Joshua Abell (Franklin, Tenn.), Laura S. Kocsis (Copley, Ohio) and Kevin Mccauley (Akron, Ohio).

According to the abstract* released by the U.S. Patent & Trademark Office: "A method for preparing cis-1,4-polydienes, the method comprising the steps of preparing a preformed, active lanthanide-based catalyst, aging the active lanthanide-based catalyst for more than 5 days to thereby formed an aged catalyst, and introducing the aged catal...