ALEXANDRIA, Va., June 10 -- United States Patent no. 12,291,687, issued on May 6, was assigned to IDEMITSU KOSAN Co. LTD. (Chiyoda-ku, Japan).
"Lubricating oil composition" was invented by Yasunori Shimizu (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A lubricating oil composition, containing a base oil (A), an aromatic carboxylic acid ester having one or more hydroxyl groups (B), and a sulfur-based antioxidant (C). A content of phosphorus atoms is 0.06% by mass or less, based on a total amount of the lubricating oil composition, and a sulfated ash content is 0.6% by mass or less, based on the total amount of the lubricating oil composition."
The patent was filed on March 2, 2022, under Application ...