CABINET CHAILLOT

T2004/21 - Technical problem, ex-post facto analysis

Technical problem based on an effect neither mentioned nor suggested in the prior art.

T2004/21
The appeal was filed by the opponent against the decision of the opposition division finding that the European patent as amended according to auxiliary request 1 meets the requirements of the EPC.
The claimed invention relates to a chewing gum which provides a hydration or "mouthwatering" sensation to a consumer. The chewing gum comprises a gum base, a flavour and a bulking agent comprising a blend of erythritol granules which includes an amount of "coarse" erythritol granules having a specific size.
D2, the closest prior art, discloses a chewing gum comprising a blend of erythritol granules of different sizes and another sugar alcohol. The chewing gum should provide desirable attributes without inducing an abrasive sensation in the mouth. D2 does not mention a mouthwatering effect.
The claimed chewing gum differs from that disclosed in D2 in that:
1) the blend of erythritol granules comprises 50 to 99 wt% of coarse granules which are retained on a sieve of 250 microns
2) the total amount of coarse erythritol in the chewing gum is at least 20 wt%
The respondent argued that chewing gums containing fine, coarse or a blend of fine and coarse erythritol granules induced a sensation of hydration, i.e. a mouthwatering effect in the consumer. It also argued that the results in the patent showed that this effect was enhanced when the chewing gum comprised a higher proportion of coarse erythritol granules, i.e. granules above 250 microns.
The appellant disputed these effects, noting that some tested chewing gums which contained 16 wt% of coarse erythritol granules or did not contain erythritol granules at all performed better than others comprising a higher proportion, namely 21 wt%, of coarse granules.
The board agrees with the appellant that the tests in the patent do not make it credible that a higher proportion of coarse granules enhances the mouthwatering effect. It considers, however, that, as argued by the respondent, the overall picture emerging from the results makes it credible that the inclusion of erythritol granules in a chewing gum induces a mouthwatering effect. This being irrespective of whether the chewing gum comprises "coarse granules" having a size above 250 micron or "fine granules" having a smaller size.
Not all chewing gums induce a mouthwatering effect. The patent teaches that certain chewing gums containing sweeteners may induce a sensation of dry mouth and the need to drink water. This makes it credible that the mouthwatering sensation induced by the chewing gums is due to the presence of the erythritol granules and that this effect can be achieved with coarse and fine erythritol granules.
Although D2 does not mention the mouthwatering effect, the results in the patent make it credible that the chewing gum disclosed in D2, which contains erythritol granules, induces it.
The appellant argued that mouthwatering was an inherent property of the chewing gum of D2 and that this document already provided a solution to the problem of providing a chewing gum inducing mouthwatering. Since there was no evidence that the claimed chewing gum induced a stronger mouthwatering effect than that of D2, the underlying objective problem was merely "the development of an alternative chewing gum".
The board does not agree. Under the established case law, if a known problem has already been solved by the prior art, the objective technical problem should be formulated as the provision of an "alternative solution" to the known problem.
However, the situation in the current case is different. Although the chewing gum of D2 has "inherent" mouthwatering properties, D2 discloses neither these properties nor the problem of providing a mouthwatering effect in a user. The claimed chewing gum can therefore not be considered an alternative solution to a known problem.
When assessing inventive step, an interpretation of the prior-art documents as influenced by the problem solved by the invention where the problem was neither mentioned nor suggested in those documents must be avoided, such an approach being merely the result of a posteriori analysis.
Formulating the problem as the provision of an "alternative chewing gum" which is meant, explicitly or implicitly, to solve the problem of inducing mouthwatering would imply that this problem, as well as its solution, was known at the filing date. This would require reading into the teaching of D2 the technical contribution which the patent makes over the prior art, namely the finding that erythritol granules induce a mouthwatering effect. This would inevitably result in an ex-post facto analysis.
For these reasons, starting from D2, the underlying objective technical problem is to be formulated as the provision of a chewing gum inducing a mouthwatering effect in a consumer.
None of the cited prior-art documents mentions the problem of providing a chewing gum providing a mouthwatering effect. This problem was apparently not even known at the filing date.
This means that, starting from D2, to arrive at the claimed chewing gum, the skilled person would have had to:
- recognise the need to provide chewing gums inducing a mouthwatering effect
- recognise that chewing gums including erythritol granules induced this effect
- modify the chewing gums of D2 by increasing the proportion of coarse erythritol granules
Without hindsight knowledge of the patent in suit, this would have required inventive skills. The patent brings up for the first time the need to provide chewing gums inducing a mouthwatering effect in the consumer. Furthermore, the patent provides the first disclosure of the beneficial mouthwatering effect of erythritol granules.
For these reasons alone, the skilled person confronted with the underlying problem would have had neither any reason nor guidance to prepare the claimed chewing gum by increasing the amount of coarse particles in the chewing gum of D2.
No incentive can be found in D1 or D3 to increase the amount of coarse erythritol granules.
The subject-matter of claim 1, as well as that of the following claims, involves an inventive step.

 

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