I like this case because the patentee’s attorney really tried all what could possibly be done in order to establish an inventive step. As the Board did its job well, too, he has failed, but it sure was an honourable defeat.
[...] The patent in suit is directed to a composition for preventing or retarding the formation of gas hydrates. Such compositions already belong to the state of the art as illustrated by document D15, which uses these compositions in order to prevent the formation of gas hydrates. [4.1]
[…] Having regard to this prior art document, the [patentee] submitted that the technical problem underlying the patent in suit was to provide further compositions inhibiting the formation of gas hydrates. [4.3]
As solution to this problem the patent in suit proposes the compositions according to claim 1, which are characterized by the fact that the ether as second additive is one of the listed six individual glycol ethers. [4.4]
[…] In D15 the formation of gas hydrates is inhibited by adding a combination of a first and a second additive, wherein the first additive is a water soluble polymer […] and the second additive is an organic compound, such as ethers. Thus, any composition including those, which contain one of the six individual ethers of the patent in suit, is within the ambit envisaged by the general disclosure of D15 and is taught to be suitable for inhibiting the formation of gas hydrates. The choice of a specific combination of a particular water soluble polymer and a particular ether, i.e. a polyvinyl caprolactam homopolymer and one of the individual six glycol ethers as indicated in present claim 1, has not been shown to result in any technical benefit vis-à-vis the closest state of the art. Therefore, this choice can neither be treated as critical nor as purposive for solving the technical problem underlying the patent in suit, but merely as an arbitrary restriction of no particular technical significance.
A list of further compounds, which according to D15 are also suitable as second additive for inhibiting the formation of gas hydrates and providing a synergistic inhibition effect, explicitly discloses the compound “2-butoxy ethanol”. This name is another expression for the identical ether compound named “ethylene glycol monobutyl ether” in claim 1 of the patent in suit. Thus, the skilled person had a clear and direct teaching in the closest prior art D15 itself on how to solve the technical problem of providing an alternative, namely to use 2-butoxy ethanol as second additive, thereby arriving at the solution proposed by the patent in suit.
For these reasons the subject-matter of claim 1 of the patent in suit turns out to be merely the result of an arbitrary choice made within the ambit of D15 and thus is obvious from the closest prior art alone. [4.7]
The [patentee], however, brought forward that D15 clearly focussed on achieving a synergistic inhibition effect, which could not be obtained with other than the specific combinations of polymers and organic compounds exemplified in Table 1. Therefore, a skilled person would not have dismantled or modified these particular synergistically effective combinations described in that document. However, since the objective technical problem consists merely in providing alternative compositions inhibiting the formation of gas hydrates the presence of a synergistic effect or not is not part of the technical problem to be solved, and therefore is irrelevant for the assessment of inventive step. [4.7.1]
[…] Further, the [patentee] argued that the passage on page 12 indicated that the authors of D15 only “believe[d]” that the synergistic inhibition effect will be observed when using 2-butoxy ethanol implying that they have not been certain thereon. Therefore, in the absence of any expectation of success the skilled man would not have seriously taken these alternatives into consideration. However, when assessing inventive step it is not necessary to establish that the success of an envisaged solution of a technical problem was certain. In order to render a solution obvious it is sufficient to establish that the skilled person would have followed the teaching of the prior art with a reasonable expectation of success (see T 249/88 ; T 1053/93 [5.14]; and T 318/02 [2.7.2]). In the present case the passage referred to rather indicates that the proposed alternatives have simply not yet been realized, but gives a clear and direct pointer to the skilled person, which makes it obvious to try the proposed alternatives in order to provide a solution to the technical problem underlying the patent in suit. Therefore, this argument of the [patentee] cannot succeed. [4.7.2]
Further, the [patentee] brought forward that due to the length of the list of possible alternatives indicated [in] D15, a skilled person would have had no incentive to specifically select 2-butoxy ethanol. However, the simple number of alternatives which a skilled person had at his disposition when looking for alternative compositions has no impact on the assessment of obviousness, since a mere arbitrary choice from a host of possible solutions does not in itself involve inventive ingenuity (T 939/92 [2.5.2-3]) [4.7.3]
The [patentee] stated further that D15 did not contain any indication of particularly combining the polyvinyl caprolactam homopolymer disclosed in Table 1 of D15 with 2-butoxy ethanol listed on page 12. However, a disclosure of that particular combination would amount to a disclosure anticipating the subject-matter of claim 1, which is not a prerequisite for successfully attacking inventive step.
The [opponent’s] objection that there is no pointer to this specific combination cannot convince the Board because this is asking for a condition to be met which is meaningless in a situation where the claimed solution merely consists in selecting components at random within the ambit of D15, as no improvement is attributable to the use of the claimed ethers of claim 1 over those defined in D15. [4.7.4]
For these reasons, the Board concludes that the subject-matter of claim 1 of the main request and, due to its identical wording, also the subject-matter of claim 1 of the auxiliary request do not involve an inventive step as required in A 56. Consequently, the main request and the auxiliary request are not allowable. 
I like the expression ‘inventive ingenuity’ used by the Board, but I am not sure that it really corresponds to a requirement of the EPC. And I definitely do not encounter it very often in the inventions I try to protect. ;-)
NB: This decision has also been commented here (in French).
To read the whole decision, click here.