13 Jul 2026
Says Federal Patent Court has invalidated German part of patent covering synthetic rubber technology for rechargeable batteries
The Hague, The Netherlands – The German Federal Patent Court (Bundespatentgericht) has "revoked" the German part of a patent held by Zeon Corp. covering synthetic rubber materials used as cathode binders, Arlanxeo announced 8 July.
The decision, it stated, follows a validity challenge by Arlanxeo to patent European patent EP 3 800 714, relating to synthetic rubber materials used as cathode binders in rechargeable battery applications.
The ruling follows a patent dispute between Zeon and Arlanxeo over battery binder technology.
In 2024, Zeon launched patent infringement proceedings against Arlanxeo entities in Germany and The Netherlands at the Munich Regional Court. (ERJ report)
Arlanxeo subsequently challenged the validity of the patent before the German Federal Patent Court.
In a preliminary opinion issued in July 2025, the Patent Court expressed "significant doubts regarding the patent's validity," according to Arlanxeo's 8 July press release.
Following that assessment, it added, the Munich Regional Court suspended the infringement proceedings pending the outcome of the validity challenge.
With the patent now "revoked" in Germany, "the legal basis for the infringement claims in that jurisdiction has been removed," according to Arlanxeo.
ERJ is contacting Zeon for comment.
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