CABINET CHAILLOT

Appeals were filed against the decision of the opposition division to maintain European patent No. 3 325 559 in amended form.
Claim 1 according to auxiliary requests 9 to 11 defines the use of a VMP pigment in a flexographic ink formulation for providing the following technical effects: "fewer print defects, higher hiding and stronger colour and allowing a lower volume anilox".
The board concluded that claim 1 does not meet the requirement of clarity under Article 84 EPC for the following reasons:
It is first observed that there is no basis - be it in the case law or in the EPC - for concluding that the limiting functional features of a use claim are exempt from the clarity requirement under Article 84 EPC or somehow exposed to lower standards in this respect. It must however be emphasised that - irrespective of whether a claim is directed to a use or to any other category of subject-matter - the mere breadth of protection does not in itself imply a lack of clarity. The decisive consideration is whether the feature(s) in question give(s) rise, or could plausibly give rise, to legal uncertainty when assessing whether a particular subject-matter falls within or outside the scope of protection conferred by the claim.
Use claims serve to establish patentability where the technical contribution resides in the identification of a new technical purpose or effect, irrespective of whether the entity as such is already known. In such cases, the definition of a use for that specific purpose or effect - applying the principles established in decisions G 2/88 and G 6/88 - constitutes a functional limiting feature which may, in itself, confer both novelty and inventive step.
Decisions G 2/88 and G 6/88, which laid down the fundamental principles for the interpretation of non-medical use claims, illustrate how the technical purpose defined in a use claim can serve to establish novelty. In the case underlying G 2/88, the claimed invention related to the use of an additive - previously known for its rust-inhibiting properties - for the new technical purpose of reducing friction. In the case underlying G 6/88, the claimed use concerned certain compounds which had previously been employed to influence plant growth, but were now used for the distinct purpose of controlling fungal infestations.
More specifically, in G 6/88, the Enlarged Board of Appeal clarified that a technical effect defined in a use claim can confer novelty, even if that effect may have been inherently achieved in a known use. In that case, the compounds in question had previously been used for influencing plant growth. It could therefore have been argued that their use for controlling fungi in plants was inherently disclosed, since both uses involved essentially the same physical steps - namely applying the compounds to the surface of the plants. However, the Enlarged Board emphasised that, under the EPC, inherent effects are analogous to secret or hidden features and as such, cannot be regarded as having been made available to the public within the meaning of Article 54(2) EPC. A clear distinction should thus be drawn according this decision between (i) implicit features: those not explicitly described, but directly and unambiguously derivable by the skilled person from the disclosure in question; and (ii) inherent features: those which may, in fact, have been present in a known use, but which remained hidden or unrecognised by the skilled person.
In decisions G 2/88 and G 6/88, as well as in most use claims upheld by the Boards, the claimed use typically relates to a technical effect or purpose that is objectively distinct from those known in the prior art. In such cases, the effect underpinning patentability may legitimately be defined in broad terms, especially where no similar technical purpose has previously been disclosed. However, as with any claim feature, broad terminology can raise clarity concerns under Article 84 EPC, particularly if it is unclear whether the skilled person can apply objective criteria to determine the exact scope of the claim. That said - the mere breadth of a feature does not, by itself, render it unclear. Extending the scope of protection is legitimate where the invention makes a non-obvious technical contribution applicable across a correspondingly broad field. Therefore, clarity objections against broad functional or purpose-related features must be balanced against the patentee's legitimate interest in avoiding undue restriction of the scope of the claims.
The situation in the present case is however fundamentally different, as both claim 1 and document D10 concern the same entity for the same, or at least an analogous, technical purpose. In particular, both claim 1 and D10 define the use of a formulation containing the same additive in a flexographic ink. The only difference is that claim 1 specifies that this use improves multiple aspects of the printing quality, whereas document D10 reports that the printing-quality parameters of the flexographic ink are comparatively inferior to other alternatives. Moreover, according to Example 2 of D2 (explicitly cited in D10), the additive in question provides the same effect as described in the opposed patent, namely the prevention of pigment agglomeration. It follows that the prior art already discloses the use of the same additive for the same, or at least very similar, technical purposes. In other words, the claimed technical effects are neither hidden nor unrecognised in D10; the only arguable distinction is that the flexographic ink in comparative Example 8 of D10 does not appear to achieve particularly favourable results in this respect.
The question then arises as to what the alleged new technical purpose might be, which could potentially establish patentability of the use claim over the disclosure in D10. The most plausible explanation is that, while D10 discloses the use of the additive in flexographic inks, it does so in the context of a comparative example presented as disadvantageous, resulting in comparatively poor printing quality. From this perspective, it is apparent that the use claim does not seek to define distinct technical effects, but rather relative improvements in the achievement of such effects. In other words, claim 1 at issue does not rely on the additive unexpectedly rendering an ink suitable for use in flexographic printing, but rather on the (alleged) finding that the additive provides better printing quality in this context compared with that previously recognised or reported in the prior art, i.e. in comparative Example 8 of D10. Therefore, the relative or comparative terms in the claim ("fewer print defects", "higher hiding", "stronger colour", "lower volume") constitute the key features supposed to distinguish the scope of the invention from the prior art, and establish its patentability.
In view of the above, the requirement of clarity can only be satisfied if the alleged relative improvements in printing-quality factors are defined in a manner that provides a clear and objectively assessable scope of protection. Otherwise, it would be impossible - contrary to the requirements of Article 84 EPC - to determine whether a particular use falls or not within the scope of the claim; for example, whether the use in comparative Example 8 of D10 is encompassed by the subject-matter of claim 1.
In the present case, the board concludes that no objective criteria are available for determining when the number of print defects, the degree of hiding, the colour intensity or the anilox volume may be regarded as sufficiently low or high for other uses to fall within or outside the scope of the claim. As a result, the subject-matter of claim 1 cannot be assessed objectively in relation to the prior art, which gives rise to legal uncertainty and therefore fails to meet the clarity requirement of Article 84 EPC.
For the sake of completeness and to avoid any misunderstandings, the board emphasises the following points:
It follows from the above that, where an invention concerns a use claim directed to a known entity for a clearly distinct technical purpose or effect - as in G 2/88 and G 6/88 - the purpose or effect may be defined in correspondingly broad and relative terms without necessarily infringing the clarity requirement under Article 84 EPC, provided that the definition of the effect enables a clear distinction between the scope of protection and the prior art, thereby eliminating the risk of legal uncertainty or at least confining such risk to speculative theoretical scenarios.
However, where a claimed invention is defined by the use of a known entity to achieve a known technical effect or purpose, and the alleged technical contribution lies in a relative improvement or enhancement of that effect or purpose, the requirement of clarity under Article 84 EPC generally demands that the feature defining such relative improvement or enhancement be expressed in objectively verifiable terms, thereby ensuring legal certainty regarding the scope of protection. In these "relative-improvement" scenarios, any imprecise functional language can blur the distinction between claimed and known uses, giving rise to the very legal uncertainty that the clarity requirement is intended to prevent.
In this respect, the notion of what constitutes a "known technical effect" should not in principle be confined to effects explicitly mentioned in the prior art, but should also encompass effects that are implicitly and recognisably associated with the entity in question in the relevant technical context. Such implicit technical purposes may form part of the common general knowledge of the skilled person, even if not explicitly stated in a given document. Furthermore, as in the present case, an effect should in principle be considered known even if the prior art presents it in an unfavourable light - for example, as comparatively inferior to other alternatives - since, in such circumstances, the alleged contribution does not lie in the recognition of the effect itself, but in the relative improvement of that effect.
The above reasoning should not be interpreted as suggesting that the requirement of clarity under Article 84 EPC may be disregarded when the features in question are not decisive for establishing patentability over the cited prior art. As explained in more detail in decision T 869/20, the underlying rationale of Article 84 EPC is to ensure legal certainty, which may be important for an objective assessment of patentability in view of the prior art, but may also become relevant in the context of infringement proceedings potentially unrelated to that prior art. Notwithstanding this, it cannot be denied that, where - as in the present case - the prior art is technically close to the claimed subject-matter, the clarity of the distinguishing features becomes all the more critical, since such proximity makes it readily apparent how vague or diffuse definitions may give rise to legal uncertainty in the assessment of patentability.
Since none of the requests submitted by the proprietor meet the requirements of the EPC, the patent is revoked.