The proprietor appealed the OD’s decision to revoke EP. 2 880 138.
The choice of the CPA
The patent (see paragraph ) seeks to provide a lubricating oil composition for internal combustion engines which not only affords good wear resistance and fuel economy but also exhibits good emulsion stability.
If the lubricating oil composition has high emulsion stability, it will keep water (a by-product of combustion) in an emulsified state, thereby preventing it from separating, coming into contact with metal surfaces and causing them to corrode.
As further set out in paragraph  of the patent, the monoglyceride component (B) of claim 1, which acts as a friction modifier and thereby imparts wear resistance and fuel economy, contributes to a reduction in emulsion stability when included in the base oil component (A) of claim 1.
The reduction in emulsion stability caused by component (B) can be mitigated or prevented by the inclusion of component (C).
In view of this teaching of the patent, there was disagreement between the parties as to whether, in addition to D8, D1 could also serve as a starting point for the assessment of inventive step.
According to the proprietor, the disclosure of D8 was closer than that of D1 to the subject-matter of claim 1. Consequently, D8 was the CPA and the assessment of inventive step could only start from D8.
The board did not agree with this contention. The concept of the CPA does not mean that a piece of prior art must be disregarded in the assessment of inventive step merely because it is allegedly not as close to the claimed subject-matter as the closest prior art.
Instead, the decisive question when considering whether to take into account an allegedly more remote piece of prior art is whether or not this prior art represents a suitable starting point (Case Law of the Boards of Appeal of the European Patent Office, ninth edition, 2019, (CLBA) I.D.3.1). With regard to D1, this question must be answered in the affirmative.
D1 (abstract) provides an improved lubricating oil composition for automotive internal combustion engines and transmissions. This composition comprises an oil of lubricating viscosity having mixed therewith a minor amount of a friction modifier composition which reduces the coefficient of friction between moving mechanical parts, thereby providing for enhanced fuel economy.
The friction modifier composition comprises a combination of two classes of compounds, the preferred representatives of which are according to components (B) and (C) of claim 1. This combination of compounds provides for synergistic fuel economy effects.
For the BA, D1 pertains to the same field of application as the patent (lubricating oil compositions for internal combustion engines). Furthermore, it employs compounds according to components (B) and (C) of claim 1 to achieve one of the goals that the patent seeks to achieve, namely enhanced fuel economy. Although D1 is silent on another problem mentioned in the patent, namely the need to improve emulsion stability, D1 and the patent have such a large overlap that the former can nevertheless be considered as a suitable starting point in the present case.
The BA came to the conclusion that the ranges for the amounts of components (B) and (C) of claim 1 of the main request overlap with the ranges disclosed in D1.
As there is no effect associated with the chosen ranges, their selection is arbitrary. The skilled person would thus have worked in the areas of overlap without needing inventive skills.
Furthermore, component (A) of claim 1 merely defines a conventional group of base oils. Consequently, the replacement of the base oil of D1 with a conventional base oil does not require inventive skills either. It follows that the subject-matter of claim 1 does not involve an inventive step.
Withdrawal of a request in first instance
During opposition proceedings, the proprietor had filed a set of claims of an AR 1 with a letter of 16 August 2018. This AR 1 was abandoned in favour of other AR filed during the oral proceedings before the OD.
The set of claims of AR1 filed on appeal differs from that of AR1 before the OD only in that claim 1 is worded in the two-part form.
For the BA, with AR1 filed on appeal, seeks protection for a subject-matter which is the same as the subject-matter previously abandoned by it during the oral proceedings before the OD.
It is thus no surprise that AR1 in appeal was not admitted in the procedure. The “trick” to clad it in two-part form did not work.
Outcome of the procedure
AR2 was infringing Art 123(2), AR 3 and 4 lacked clarity under G 3/14, so that the revocation was confirmed.
This decision shows once more that the CPA is not necessarily the document having the most features in common or in other words the less differences with the claim at stake.
What matters more is that it pertains to the same field of application as the patent and hence represents a suitable starting point.
A request abandoned in first instance has very little chance to be admitted in appeal. But this should not be a scoop,