Eugen Seitz AG v KHS Corpoplast GmbH & Co KG & Anor

Post-trial disclosure remains subject to the overriding requirement of necessity, together with proportionality and the overriding objective. The later timing of an application makes proportionality particularly important. Disclosure of secondary evidence from an inventor or participant may be relevant to obviousness, but it is not automatically necessary. Such evidence is an aid to assessing primary evidence and must not obscure that primary evidence. Where technical prejudice is an issue, evidence of the reaction of a major market participant may be relevant because the prejudice must be commonly shared and widespread. A focused search for documents known to exist or readily discoverable may be ordered, while a broader renewed disclosure exercise may be disproportionate.

The claimant sought specific disclosure after trial in patent revocation proceedings. The patent concerned plastic pistons for high-pressure valves in rotary stretch blow moulding machines. Novelty and obviousness were in issue, including whether the industry had a technical prejudice against using plastic in such valves.

The application followed information supplied by a former employee of the second defendant. The claimant sought documents concerning the use and manufacture of PET components and a proposed supply of PET pistons to Sidel. The court had to determine whether further disclosure remained necessary and proportionate after trial, and whether the Sidel documents could materially assist on obviousness.

1. Disclosure obligation. The parties’ obligation to disclose relevant documents continues after trial. The governing principle is necessity, subject to proportionality and the overriding objective. The court refused further disclosure concerning in-house manufacture because the request was broad, extended beyond the application, and added little to the evidence already disclosed.
2. Secondary evidence and obviousness. The court applied Nichia Corporation v Argos Ltd [2007] F.S.R. 38. That decision did not establish that disclosure from an inventor is necessarily relevant or necessary. Its relevance depends on the particular case. The court also approved the observation in the Mölnlycke case that secondary evidence has a place, but remains an aid in assessing primary evidence.
3. Sidel documents. The fact that Norgren had considered proposing PET pistons was not, by itself, sufficiently relevant to justify further disclosure. However, Sidel’s reaction could be relevant to whether technical prejudice was widespread, given Sidel’s substantial market share and its continued use of metal pistons. The material was therefore potentially relevant to an important issue at trial.
4. Order. A limited search and disclosure of the documents gathered by Mr Bauer and sent to Mr Dell’Oca in 2009 was ordered, as those documents were known to exist and could readily be revealed. A search extending to Norgren France, or a wider renewed disclosure exercise, was refused as disproportionate. The disclosure did not admit the documents into evidence or foreshadow any decision on an application to reopen the trial or amend the validity case.

First-instance decision on an application for specific disclosure made after trial in patent revocation proceedings. No prior appellate decision is stated in the judgment.