Huntsman (EUROPE) v BASF (CFI, 22 April 2026)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

In a decision of 22 April 2026 (UPC_CFI_461/2025), the Paris Central Division, ruling on the revocation action brought by Huntsman (Europe) and Huntsman Holland against BASF’s EP 1 516 720, on a composite element containing a polyurethane adhesion promoter, holds that the patent as granted is invalid and must be maintained in the amended form of auxiliary request 1 (paragraphs 142 and 143). The decision admits the action although the patent expired on 7 August 2024, the interest in bringing proceedings surviving because damages claims remain possible.

Facts and procedure

On 16 July 2024, BASF had obtained in Belgium an ex parte evidence preservation measure against Huntsman (Europe), for indirect infringement alleged against Huntsman Holland. On 6 June 2025, the Huntsman companies sought revocation of the patent ex tunc for ten states (Austria, Belgium, Bulgaria, Germany, France, Italy, Portugal, Romania, Sweden and Slovenia), for lack of novelty and inventive step. BASF asked for dismissal and, in the alternative, maintenance of the patent under one of auxiliary requests 1 to 11, whose numbering was corrected during the proceedings.

The applicable law

Article 65 UPCA and Article 138(1)(a) EPC allow revocation for lack of patentability (Articles 54 and 56 EPC), amendments must not extend the subject matter beyond the application as filed (Article 123(2)). Construction follows Article 69 EPC and the Court of Appeal’s NanoString case law. Neither the Agreement nor the Rules of Procedure make a revocation action against an expired patent inadmissible (paragraph 12).

Question

Is a revocation action admissible against an expired patent, and is the patent, as granted or amended, novel and inventive?

Decision

The interest in bringing proceedings, examined of the Court’s own motion, exists: damages remain possible for the period of validity, and the claimants are directly targeted by the Belgian proceedings (paragraphs 11 to 15). Purely editorial corrections to the auxiliary requests are admitted (paragraphs 16 and 17). The panel is not bound by the problem stated in the patent and reformulates it around adhesion between the polyisocyanurate foam layer and the cover layer (paragraphs 36 to 39). The granted claims are novel over D11 and D14 and claim 1 is inventive over D11 (paragraphs 66 to 101), but inventive step is lacking over D19, the claimed densities lying within customary ranges (paragraphs 102 to 117). D22 does not change the outcome (paragraphs 118 to 123). Auxiliary request 1, which adds a polyol-based reaction and an NCO/OH ratio of 0.8 to 1.8:1, does not extend beyond the application as filed and withstands the objections raised, the panel considering only the claimants’ arguments (paragraphs 124 to 139).

The order dismisses the revocation action insofar as it goes beyond auxiliary request 1 and maintains the patent in that form (item 2 refers to « EP 1 516 729 »), with nine process, product and use claims (paragraph 143). Since both sides partly succeed, and the limitation is not the only reason for dismissal, costs are apportioned 70% to the claimants and 30% to BASF, as BASF made no costs request, the division rules under Art. 76 UPCA only on the claimants’ costs, 30% of which BASF bears (paragraph 146). The value in dispute is set at EUR 1,500,000 (paragraph 144), and the decision will be sent to the EPO and the national offices once the time for appeal has expired.

Key points for practice

• Expiry of the patent does not make a revocation action inadmissible where damages claims remain possible (paragraphs 12 and 13).
• The objective technical problem is determined from the patent’s overall teaching, not merely from the object stated in the description (paragraphs 37 to 39).
• The validity of auxiliary requests is examined only against the objections actually raised by the revocation claimant (paragraph 124).
• Practical point: the target of evidence preservation based on an expired patent may bring a revocation action before the UPC to neutralise a future damages claim, setting out its objections against each auxiliary request.

Provisions applied

Agreement on a Unified Patent Court

Arts 65(1) and (2), 69(1) and 76

European Patent Convention

Arts 54, 56, 63(1), 69, 123(2), 138(1), 139(2)

Case law cited

NanoString v 10x Genomics, Court of Appeal, 26 February 2024, VusionGroup v Hanshow, Court of Appeal, 13 May 2024, Meril v Edwards, Court of Appeal, 25 November 2025, Veolia Propreté v Tiru, Paris Central Division, 18 March 2026

Prepared by Dhenne Avocats from the official decision, consulted on 10 October 2026. The database is updated every week, on Friday. Only the official text is authoritative.