German Court Revokes Zeon Battery Binder Patent After Arlanxeo Challenge

The German Federal Patent Court has revoked the German part of a European patent held by Zeon Corp. covering synthetic rubber materials used as cathode binders in rechargeable batteries. The patent, EP 3 800 714, was challenged by Arlanxeo, a Dutch synthetic rubber major, which argued that the patent was invalid. The court’s decision follows a patent dispute between Zeon and Arlanxeo over battery binder technology, which began in 2024 when Zeon launched infringement proceedings against Arlanxeo entities in Germany and The Netherlands. Arlanxeo subsequently challenged the validity of the patent before the German Federal Patent Court, which expressed significant doubts regarding the patent’s validity in a preliminary opinion issued in July 2025. With the patent now revoked in Germany, the legal basis for the infringement claims in that jurisdiction has been removed. John Gerrese, general counsel at Arlanxeo, welcomed the court’s decision, stating that it confirms the company’s position on the invalidity of the patent and highlights the importance of robust patent standards. The ruling is significant for the electric vehicle and energy storage industries, where synthetic rubber materials used as cathode binders are of growing importance.