The appeals of the patent proprietor (appellant 1) and the opponent 1 (appellant 2) lie from the opposition division's decision finding that European patent No. 3 400 316 in amended form based on auxiliary request 2 met the requirements of the EPC.
Claim 1 of the main request refers to a 6xxx aluminum alloy defined by ranges of Si, Mg, Cu, Fe, Mn, Cr, Ti and Zn.
In claim 1 of auxiliary request 2, the range of Ti has been amended.
D1/D1a discloses an alloy C1 falling within the scope of claim 1 except that alloy C1 contains 1.00 wt.% Si. The opponents mainly argued that the lower endpoint of the claimed range (1.03 wt.%) could not establish novelty since it was not far removed from the example.
The concept that a claimed sub-range must be "narrow" compared to the known range and "sufficiently far removed" from any examples disclosed in the prior art originates from several decisions. It has been accepted as a kind of novelty test for selection inventions. This board agrees with T 1688/20 that this concept is not in agreement with direct and unambiguous disclosure, which is the uncontested criterion established later on in the case law for evaluating novelty. The relative terms "narrow" and "sufficiently far removed" do not provide objective, solid and consistent criteria for establishing the novelty of a selected sub-range. Therefore, these terms are dependent on the case and context and involve considerations linked to the technical effect of the range. It is considered to be relevant for inventive step.
In the case in hand, the ranges cannot be regarded individually but only in combination. In addition, an example is an embodiment that cannot be combined with the description.
For multiple ranges, the concept of "seriously contemplating" is not in line with direct and unambiguous disclosure. Instead, when multiple ranges are involved, "seriously contemplating" is linked to the desired effect, which implies considerations known for inventive step.
The alloy claimed can only be arrived at by choosing several endpoints from the disclosure of D1/D1a. This cannot be considered direct and unambiguous disclosure.
To summarise, D1/D1a does not anticipate the subject-matter of claim 1 of the main request.
D1/D1a is a suitable starting point for inventive step. D1 has an objective similar to the patent. The fact that the alloy of claim 1 of the current request is intended for automotive applications is irrelevant since such a feature is not part of claim 1. Claim 1 is a product claim and not a use claim.
The problem to be solved by the patent is to provide an alloy having an improved combination of strength, formability and/or corrosion resistance.
The patent proposes to solve the problem by an alloy according to claim 1 characterised in that the alloy contains 1.03 to 1.40 wt.% Si.
It is not credible that the problem is successfully solved since D1/D1a also relates to an improved combination of properties. There is no evidence that a small change in Si compared to alloy C1 of D1/D1a would lead to an improved combination of properties. Such an improvement is also not apparent from the data in the patent. Therefore, the board agrees with the opposition division that an effect over D1/D1a is not credibly shown for the change in Si. Consequently, the problem needs to be redefined in less ambitious terms and can be seen as the provision of an alternative alloy.
If the problem to be solved is the provision of an alternative, the presence of an incentive towards the solution is not mandatory.
Starting from alloy C1 of D1/D1a, the skilled person has many options to vary the components in view of the general teaching given in claims 1 and 2 of D1/D1a. It is true that D1/D1a teaches that the amount of Si and the amount of Mg should be balanced, but there is no clear teaching on how this balance should look. The skilled person understands that working in the preferred ranges of Si and Mg already implies the right balance. When working within these ranges, some of the possible alloys will not fall within the scope of the claim, but many others will. However, a mere arbitrary choice made from the possible solutions cannot be regarded as involving an inventive step.
Therefore, the subject-matter of claim 1 lacks an inventive step in view of D1/D1a alone.
Regarding Auxiliary request 2, Opponent 1 argued that the change of "consisting essentially of" to "consisting of" was not directly and unambiguously derivable from the application as originally filed.
Claim 1 of the application as originally filed lists the same components as claim 1 of the current request. In addition, the balance was defined as aluminium and impurities. It is evident from the exemplified alloys that preferably no component other than those listed is present. Therefore, the change from "consisting essentially of" to "consisting of" is directly and unambiguously derivable from the application as originally filed.
The requirements of Article 123(2) EPC are met.
The problem to be solved by the patent is to provide an alloy having an improved combination of strength, formability and/or corrosion resistance.
The patent proposes to solve the problem by an alloy according to claim 1 characterised in that the alloy contains 1.03 to 1.4 wt.% Si and 0.06 to 0.14 wt.% Ti.
It is accepted that the problem is successfully solved. The comparison of alloys CC1 and CC3, which mainly differ in the content of Ti (0.09 vs 0.026), shows that alloy CC1 has improved corrosion resistance.
Opponent 1 argued that CC1 and CC3 also differed in their Mg contents and consequently in the ratio of Si:Mg. Therefore, the effect could not be attributed to Ti alone.
Opponent 1 has not submitted any data to corroborate its allegation. In addition, its position is not in line with the position taken for the main request. If a difference of 0.03 wt.% for Si is supposed to be without effect, it is not credible that a difference of 0.01 wt.% for Mg would have a noticeable effect.
Consequently, there is no need to redefine the problem in less ambitious terms.
There is no incentive to increase the amount of Ti to 0.06 wt.% or more.
The subject-matter of claim 1 involves an inventive step, as well as dependent claims 2 to 12.