Arlanxeo: German Federal Patent Court revokes Zeon Corporation battery patent

The German Federal Patent Court has declared invalid the German part of European patent EP 3 800 714 held by Zeon Corporation. Synthetic rubber manufacturer Arlanxeo announced the decision on July 8, 2026. The patent covers synthetic rubber materials used as cathode binders in rechargeable batteries for electric vehicles and stationary energy storage systems.

The ruling follows a patent dispute between Zeon Corporation and Arlanxeo. In 2024, Zeon filed patent infringement lawsuits against Arlanxeo companies in Germany and the Netherlands before the Munich Regional Court. Arlanxeo subsequently challenged the validity of the patent by filing a nullity action with the German Federal Patent Court.

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In a preliminary opinion issued in July 2025, the Federal Patent Court had already expressed significant doubts regarding the validity of the patent. As a result, the Munich Regional Court stayed the patent infringement proceedings pending the outcome of the nullity action.

According to Arlanxeo, the revocation of the German part of the patent removes the legal basis for the patent infringement lawsuits in Germany. The decision applies exclusively to the German part of the European patent and does not affect its validity in other countries.

More information: www.arlanxeo.com, www.zeon.co.jp

Arlanxeo Holding B.V., Den Haag, Niederlande