Valero, unocal still at it over patent

摘要

Valero Energy and Unocal continue to duke it out over Unocal's clean gasoline patents. Valero June 28 announced the US Patent and Trademark Office, upon reexamination, had rejected Unocal's 126 patent claim. The action is similar to the PTO's rejection last February of Unocal's 393 patent.