Excluding a technical effect, without evidence, cannot amount to an inventive step

In T1856/22, the Board of Appeal (the Board) considered the inventive step of a composition, where the only distinguishing feature was a lower concentration of a component, as compared to the closest prior art. The prior art taught that a higher concentration was essential. The Board found that excluding a technical feature essential in the prior art cannot in itself establish inventive step, if no evidence is shown to prove that excluding this feature can still provide the technical effect as taught by the prior art. 

G2/21 was mentioned but not applied, since the Board found that the patentee’s (P) evidence to support the missing technical effect, was late filed under Art. 13(1) and (2) RPBA. 

Background

In the decision under appeal, the Opposition Division (OD)’s decision to maintain EP 3374443 in amended form was appealed by the Opponent (O). Claim 1 of the main request of EP337443concerns a stripping composition, typically used to remove paints or resins from a metal surface. 

These compositions, as also evidenced by D7, usually comprise three elements:

            - a penetrating agent, an organic solvent which swells or solubilises the coating (e.g. paint);

            - an accelerator, a strong alkali, which breaks down the coating, allowing it to be stripped; and

            - a coupling agent, an alcohol, which brings components 1 and 2 together to form a single-phase stable mixture.

Both O and P agreed that the only difference between D7 and claim 1 was the lower amount of coupling agent in claim 1 than in D7. In D7, as the coupling agent was 25% of the composition whilst claim 1 specified 2-20%. The issue at hand was whether claim 1, which differs only by the lower concentration of coupling agent, was inventive over D7.

The application as filed did not state a technical effect for the lower concentration of coupling agent. However P argued that the skilled person would not have reduced the amount of the coupling agent, because D7 states that high concentrations of the coupling were essential for the stripping composition to have an appropriate tolerance to water. Based on this argument, the OD acknowledged an inventive step over D7.

The appeal

The OD’s decision to maintain EP3374443, led to the appeal by the Appellant/Opponent (A). 

During the appeal, the A submitted that the lower concentration of coupling agent is the only feature that distinguishes claim 1 from D7 which by itself is not inventive, since arbitrarily changing the concentrations in a composition is routine for the skilled person. In response, the Respondent/Patentee (R) submitted, for the first time during the appeal proceedings, that the subject matter of claim 1 of the main request further differs from example 2 of D7 in being non-aqueous and more tolerant to water than D7’s composition.. The Board did not admit either of these submissions, at the request of the A (see further below).

Consequently, the Board found that there is no technical effect associated with providing an alternative stripping composition.

Decision of the Board

The Board disagreed with the OD. It found that, based on D7, if reducing the concentration of the coupling agent worsens water tolerance, then, from a logical point of view, the same applies to claim 1. And if this is true, then the objective technical problem becomes the provision of a stripping composition with a poorer water tolerance. The solution– reducing the amount of coupling agent – would have been obvious to the person skilled in the art. 

In situations such as the present one, it must be shown that the claimed subject matter achieves the technical effect to an extent comparable to that of the closest prior art, even without this feature. Without such proof, the claimed subject matter merely results in an obvious deterioration of the technical effect described in the closest prior art. It would follow that the subject matter of claim 1 of the main request is not inventive over D7 alone.      

Submissions by the R

R’s submissions, regarding the additional technical effects of the composition being non-aqueous and more tolerant to water, where both made during proceedings before the board, so Art. 13(1) and (2) RPBA applied. The Board therefore considered whether these submissions amounted to an amendment of R’s appeal case under Art. 13 RPBA. The Board briefly cited G2/21 and whether the R could rely on it to have these (late filed) technical effects taken into account, but the Board found G2/21 inapplicable to the present case.

R argued that the additional technical effects could be found in its submissions before the OD, and therefore should be considered part of its appeal case. The Board disagreed and stated that established case law dictates that the parties’ written submissions filed before the OD do not automatically form part of the appeal proceedings, not do they become part of the proceedings merely by resubmitting them on appeal and referring to it in general terms. Thus the Board maintained its opinion that it constituted an amendment to the R’s case. Admitting these submissions would be contrary to procedural economy Art. 13(1) RPBA.

At the end of oral proceedings, R raised a Rule 106 EPC objection against the Board’s decision not  to not admit any of the R’s submissions. R was of the opinion that the Board’s decision violated its right to be heard under Art. 113(1) EPC. Once again, The Board disagreed with the R and did not see any procedural defect in these non-admittance decisions. According to the Board, the R had sufficient opportunity to comment on the admittance of its submissions before the appeal proceedings took place, but had not done so. Hence, there can be no violation of the R’s right to be heard in this respect. Therefore the board decided to dismiss the R’s objection and revoked the patent.

Summary written by the NLO EPO Case Law Team