There’s an alternative, and then there’s an ‘alternative’ - T 1468/23

In T 1468/23, three different formulations of the objective technical problem were considered – the provision of: (a) an improved friction material, (b) an alternative material that is comparable to those described in the closest prior art and (c) a ‘working’ alternative material, merely suitable for use as a friction material.  To the patentee’s detriment, the Board adopted the least ambitious formulation.

Background

Claim 1 as granted related to a friction material comprising “3-10% by volume abrasive material having a Mohs hardness of 7 or higher”.

Mohs scale ranges from 1 to 10, with 1 being assigned to talc and 10 being assigned to diamond.

The closest prior art (D1) disclosed a friction material comprising an abrasive material making up approximately 15-30% by volume of the composition.  The description of D1 also listed several abrasive materials, some of which had a Mohs hardness of 7 or higher.

D1 also taught that ‘hard’ abrasives (those with ‘higher’ Mohs hardness values) should be used in ‘low’ concentrations, while the ‘mild’ abrasives (‘lower’ Mohs hardness) should be used in ‘higher’ concentrations to achieve the same desired friction level. 

Claim 1 differed from D1 in the volume content of the abrasive material and the specific Mohs hardness.

Paragraph [0033] of the patent in suit taught that using a content of 3 to 10% by volume abrasive material having a Mohs hardness of 7 or higher results in an improved friction coefficient during high-speed high-load braking and reduced attacking against mating materials.

Examples 1 to 11 of the patent demonstrated performance of the claimed friction materials in terms of frictional properties, wear resistance and attacking against mating materials.

One comparative example showed that the use of 2% by volume of an abrasive material having a Mohs hardness of 7 or higher leads to low effectiveness under high load and a high friction coefficient at low temperatures (potentially causing noise), in contrast to the inventive examples.

Another comparative example showed that using 6% by volume of an abrasive having a Mohs hardness of less than 7 leads to a poor performance in terms of frictional properties, wear resistance and the property of attacking mating material compared to the inventive examples. 

There were no other relevant documents on file.

During opposition

The Opposition Division (OD) followed the patentee’s proposed definition of the objective technical problem, i.e. the provision of a friction material having an improved friction coefficient during high-speed high-load braking and reduced attacking against mating materials.

The OD relied on the comparative example demonstrating poor performance of a material comprising 6% by volume of an abrasive having a Mohs hardness of less than 7.

Notably, the OD stated that “[e]ven though the comparative examples did not show the behaviour of the friction materials having higher concentrations of abrasives […], a technical effect had to be acknowledged” with respect to D1.

The OD considered that there would have been no incentive for the skilled person to modify the teaching of D1 to use an abrasive material having a Mohs hardness of 7 or higher in an amount of 3-10% by volume.

The OD also noted that Examples 8 and 13 of D1 (those using the lowest possible amount of an abrasive material according to the teaching of D1, i.e. 15% by volume) had ‘bad’ friction performance results.

Example 8 of D1 stated that the “friction performance characteristic was marginally acceptable in this case, suggesting lowering of the abrasive level further would negatively impact the fiction performance of the formulation”

Example 13 of D1 described the material as having “average friction characteristics”.

The OD considered that those examples of D1 taught away from the use of lower amounts of an abrasive material.  It is notable that the OD made this comment when addressing the framework proposed by the opponent, i.e. that of providing an ‘alternative’ friction material.

On appeal

The Board pointed out that none of the comparative examples in the patent included an abrasive material in an amount higher than the limit of claim 1, let alone in the range taught by D1.  In all but one of them (2% by volume), the amount of the abrasive material was 6% by volume.

In addition, there was only one comparative example which included an abrasive material having a Mohs hardness outside of the claimed range; the example included the material in an amount of 6% by volume.

The Board concluded that the comparative examples in the patent are not representative of the disclosure of D1.  Unlike the OD, the Board thus disregarded the comparative examples when comparing the claimed invention and the teaching of D1.

Accordingly, the objective technical problem had to be formulated as a provision of an alternative friction material.  However, there were two meanings to an ‘alternative’ material: (i) a material that is comparable to those of D1 (more ambitious formulation) or simply (ii) a working alternative to the materials of D1; a material suitable for use as a friction material (less ambitious formulation).

Formulation (i) would have been more beneficial for the patentee.

According to the Board, formulation (i) was akin to the situation when a proprietor alleges an improvement over the closest prior art, namely, it was up to the proprietor to show that the improvement was credibly achieved, based on evidence or the common general knowledge.

Formulation (i) would also go against the teaching of Example 8 of D1, according to which “lowering of the abrasive level further [below 15% by volume] would negatively impact the fiction performance of the formulation”.  According to the Board, “if the teaching of D1 were found to be incorrect or unfounded, this finding should be supported by appropriate evidence”.

The Board considered that formulation (i) was unfounded - the comparative examples in the patent were not representative of the teaching of D1.  There was thus no evidence on file that the compositions of Examples 1 to 11 of the patent displayed comparable properties to the compositions of D1.

The objective technical problem was thus formulated in a less ambitious way, as the provision of a ‘working’ alternative (formulation (ii) above).

The Board noted that although D1 teaches that lowering the amount of the abrasive material negatively affects the frictional properties, the skilled person looking to solve the objective technical problem would not have sought to match the performance of the compositions of D1.  Instead, the skilled person would have reduced the content of the abrasive material, accepting a reduction in performance and obtaining a composition that is suitable for use as a friction material.

Claim 1 as granted was thus found by the Board to lack an inventive step over D1. 

Conclusions

T 1468/23 shows that defining the objective technical problem as the ‘provision of an alternative’ is not always fatal for the patentee, but in some cases it can place them in very dangerous territory before certain Boards.

In this case, the Board gave the patentee no benefit of the doubt, scrutinizing the examples of the patent in detail and requiring concrete evidence to support the “more ambitious alternative” formulation, thus treating it much like a situation where an improvement over the prior art is alleged.

Also notable is the contrasting interpretation of Example 8 of D1 within the framework of providing an alternative material.  The OD regarded it as a teach away, whereas the Board concluded that reducing the abrasive content would have yielded an (alternative) material with foreseeable disadvantages, yet still suitable for use as a friction material.

If you would like to discuss strategies for EPO prosecution more generally, 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.