More guidance on applying G 2/21 - T 1950/23

T 1950/23 is another decision applying the principles of G 2/21. It demonstrates a relatively patentee-friendly approach to assessing compliance with the requirements of G 2/21, and reminds us of a number of several aspects that could prove key in this context.

Background

Claim 1 of the Main Request was directed to a zinc-free transmission oil composition comprising, inter alia, a detergent (broadly defined as sulphonate, phenate or a mixture thereof).  Claim 1 of the application as filed did not refer to a detergent.

The distinguishing feature in view of the closest prior art was the presence of the detergent.

The patentee wanted to rely on an improvement in extreme pressure performance and filed supplementary experimental data to support this effect.

The opponent-appellant argued that the purported effect should not be taken into account in line with G 2/21.

The decision

The Board first pointed to a passage in the application as filed, which generally disclosed that the (zinc-free) compositions of the invention exhibited both improved friction characteristics and extreme pressure performance, even in the absence of zinc dithiophosphate.

The Board also referred to the disclosure in the application concerning further additives that could “impart or improve any desirable property of the lubricating composition”.  Many additives were mentioned, including detergents.  However, original claim 7 as dependent on claim 1 specifically defined the presence of a detergent selected from a sulphonate, a phenate or a mixture thereof.  Claim 8 as filed was the only other claim dependent on claim 1 relating to additives and defined the presence of a friction modifier.  According to the Board, the “dependent claims are generally directed to preferred embodiments of the invention”, and so this indicated “a higher ranking for detergents and friction modifiers as additives over other additives listed in the application as filed”.  In addition, all exemplified compositions according to the invention in the application as filed included a sulphonate or phenate detergent, and those examples were shown to exhibit adequate extreme pressure performance.

The Board thus concluded that there was a link in the application as filed between the compositions of claim 7 and the effect of extreme pressure performance as generally mentioned in the context of the compositions disclosed in the application.

The opponent-appellant argued that it was not derivable from the application as filed that an improvement in the extreme pressure performance stemmed from the distinguishing feature, i.e. the presence of a sulphonate and/or phenate detergent.

The Board agreed; however, the Board referred to T 1989/19, noting that once a technical effect is deemed to meet the criteria of G 2/21, the same applies to an improvement in that effect (it is “to be regarded as implicitly derivable”).

The Board then noted that it is often the case during post-grant proceedings that new (previously unknown to the proprietor) prior art documents are cited, and that those documents may have different features in common with the invention than the citations known to the patentee at the time of filing of the application.

According to the Board:

“[i]t is not reasonable to expect patent applicants, at the time of drafting the application, to safeguard against the citation of then unknown prior art […] by providing comparative data showing an improvement for all potential distinguishing features over all potentially later cited closest prior art documents. Not only would this be unreasonably burdensome, it would also suffer from the shortcoming that […] the information required to set up appropriate comparative tests representative thereof would not be at hand.

As a consequence, it would be an overly strict interpretation of G 2/21 to require that the application as filed demonstrate that the improvement of a technical effect disclosed in the application as filed and relied on by the patent proprietor is specifically attributed to the distinguishing feature.”

According to the Board, doing otherwise would enable the opponents to revoke patents merely by citing new documents having different distinguishing features compared to the documents known at the time of filing; in addition, it would preclude applicants and patentees from relying on post-published data as per G 2/21.

Thus, the purported effect of an improvement in extreme pressure performance was deemed to satisfy the requirements of G 2/21.

Summary

In T 1950/23, the Board noted that it would be an overly strict interpretation of G 2/21 to require that the application as filed demonstrate that the improvement in a purported effect is specifically attributed to the distinguishing feature.  This gives more room for manoeuvre for patentees and applicants to successfully rely on post-published data for inventive step.

The present decision also confirms the teaching of T 1989/19 (the ‘tiotropium bromide’ decision from the same Board), namely that once a technical effect is derivable from the application as filed in line with G 2/21, the same applies to an improvement in that effect.

Finally, T 1950/23 reminds us of several aspects that could prove key in the context of compliance with the requirements of G 2/21: reliance on preferred features/dependent claims when amending claims, absence of other preferred features in a given context and the content of the examples of the original application.

If you want to understand how the Boards of Appeal are currently applying G 2/21, I’ve covered the key decisions in a recent webinar.

If you have any questions about EPO practice, feel free to get in touch.  

This article is for general information only and is not intended to constitute legal advice. If you would like tailored advice on a specific matter, please do not hesitate to contact me.