ALEXANDRIA, Va., June 5 -- United States Patent no. 12,275,807, issued on April 15, was assigned to SUMITOMO RUBBER INDUSTRIES LTD. (Kobe, Japan).

"Rubber composition and crosslinked rubber molded product" was invented by Hiroshi Tadaoka (Kobe, Japan) and Kazuyoshi Shiga (Kobe, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "An object of the present disclosure is to provide a rubber composition containing an organic sulfur compound from which a molded product having a high hardness can be obtained. The present disclosure provides a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, (d) a benzothiazole derivative, and (e) an organic sulfur compound...