UPC CD Paris says expired BASF patent still open to attack, makes own determination of technical problem

Context: BASF SE owns EP1516720 (“Composite element comprising a polyurethane adhesion promoter”), which relates to composite insulation elements that use a polyurethane adhesion promoter to improve bonding between layers. The patent was granted on August 7, 2004, and expired on August 7, 2024. Huntsman claimed BASF had taken evidence-preservation action in Belgium and said it would claim damages on alleged prior infringement in the lifetime of the patent.

What’s new: The Paris seat of the Unified Patent Court’s (UPC) Central Division (CD) on April 22, 2026 dismissed the revocation action by two Huntsman entities. Despite the patent’s expiration, the court permitted the lawsuit to continue because it deemed the contested claims to be more innovative and novel than the referenced prior art.

Direct impact: BASF can pursue any claims for damages related to claimed pre-expiry infringement, as the patent’s validity for the duration it was in effect has been maintained. Huntsman’s attempt to have the patent retroactively invalidated was unsuccessful.

Wider ramifications: The ruling confirms that expiry alone does not shield a European patent from UPC revocation proceedings if legal consequences still remain a threat. The decision also says the court is not bound by how the patent specification describes the objective technical problem, but can make its own determination. The judgment furthermore adds to the UPC’s growing body of case law on claim interpretation, novelty, inventive step, and the role of the objective technical problem in validity disputes.