EP 2 715 892 B1 relates to a gas insulated switchgear having a fluorine compound.
Brief outline of the case
The opposition was rejected and the opponent appealed.
The board held that the subject-matter of claim 1 as granted as well as claim 1 of AR2-9 were insufficiently disclosed. AR2 was lacking IS over a document quoted in the ISR established by the EPO and AR10-12 were not taking into account under Art 13(2) RPBA. The patent was thus revoked.
A request for the reimbursement of the appeal fee by the opponent was rejected.
In this post we will concentrate on sufficiency.
The proprietor’s point of view on the lack of sufficiency
The proprietor did not acknowledge that the feature “an electrically insulating gas comprising at least one fluorinated compound with a global warming potential GWP of less than 3500” gave the claim a “reach through” character, i.e. the claim relates to a chemical compound defined only in functional terms.
For the proprietor any fluorinated compound is suitable for electrical insulation in medium- or high-voltage equipment.
The proprietor argued that the patent discloses examples in paragraph [0015]. Those examples disclose broad classes of compounds, namely fluoroketones, hydrofluoroolefins, hydrofluorocarbons, fluoro-oxiranes, hydrochloroolefins and hydrofluoroethers. For these classes, a few individual compounds are disclosed by way of example.
The proprietor further argued that the invention was not aimed at finding all the compounds suitable as low-GWP insulating gases. On the contrary, an apparatus using such an insulating gas formed the backdrop against which the invention was carried out. The current invention aimed to avoid heat loss by managing the condensate, ensuring that a sufficient quantity of insulating gas was present in the gas phase.
In addition, the argued argued that treating the present claim as “reach-through” was a misapplication of the Guidelines, F-III.9. This chapter of the Guidelines concerned inventions in the field of biotechnology and, more importantly, compounds characterized solely by their effect or function.
This was not the case here. Rather, the GWP was an accepted and customary parameter that could be determined without difficulty for a given compound.
The opponent’s point of view on the lack of sufficiency
The opponent pointed out that major efforts are being made to replace SF6 as an insulating gas. In fact, it is difficult to find promising alternatives such as some of the fluoroketones listed in the prior art.
Insulating power is not the only criterion for suitability. Another difficulty, is the boiling point. Potential insulating gases must have a boiling point that is not too high. Gases that are too corrosive or harmful are also unsuitable for the devices claimed.
In addition, it is not just a question of finding insulating gases, but also gases with sufficient arc-extinguishing capacity. In addition, there is the need to identify gases that do not decompose too quickly under the effect of arcs. SF6 decomposition products, for example, appear to recombine sufficiently not to empty the SF6 enclosure too quickly, and so do not appear to require refilling too frequently. The problem seems to be more pronounced with some of the fluoroketones, but can be solved by providing a liquid reservoir.
The board’s decision on sufficiency
The claim requires an insulating gas in a medium- or high-voltage gas-insulated electrical appliance. The skilled person must find among the vast class of fluorinated compounds those having both a PRG below 3500 and an ability to make an insulating gas in a medium- or high-voltage appliance.
The board was not convinced by the argument that any fluorinated compound is suitable for electrical insulation in medium- or high-voltage equipment.
The examples in the patent relate themselves to broad classes of compounds, see above.
The board was convinced that there are fluoroketones suitable for the electrical insulation of electrical appliances as claimed. However, the rest of the examples are presented without any proof of their suitability. Some of these examples are even clearly erroneous, such as “HFO 1336 mzzzM” or “C7F18O”.
The board held that it is not sufficient to present a few broad classes of fluorinated compounds and a few specific individual examples with a desired GWP without proof that in essence all members of the compound classes meet all the criteria for suitability as insulating gases for medium- or even high-voltage switchgear.
The patent at stake appears neither to name the criteria, nor to contain any general information or general guidelines that might guide a person skilled in the art to find, among the vast classes of compounds claimed, those that satisfy the constraints imposed by the claim.
The requirement of sufficiency of disclosure concerns the invention as a whole, and not just the part which the applicant or proprietor considers to be the inventive contribution. If any part of the invention defined in the claims cannot be realised, then that invention can be the subject of an objection for insufficiency of disclosure.
If this is not the case, speculative patents may have to be granted on the grounds that their subject matter relates in part to feasible construction details, even though this subject matter may not be feasible in its entirety.
Contrary to the proprietor’s contention, the technical scope of a claim is irrelevant when the claim is qualified as “reach-through”.
The bord noted that the Guidelines specify that claims directed to merely functionally defined chemical compounds that are to be found by means of a new kind of research tool are directed to future inventions, for which patent protection under the EPC is not designed.
The claim covers all compounds with a GWP of less than 3500 and having the function of an insulating gas for medium and/or high voltage.
The patent contains no clear indication as to their identity, beyond an indication that these compounds contain fluorine. The proprietor simply asserts, without providing any evidence, that a person skilled in the art could find suitable compounds using only their ordinary skills, and given a suitable compound, the GWP could be determined.
This represents exactly the case described in the Guidelines, namely that in reality, the respondent is trying to patent what has not yet been invented, and the fact that the effects used to define compounds can be tested does not mean that the claim sufficiently exposes the invention. The claim is in fact an invitation to carry out a research program.
Comments
Reach trough claims are a relative rare occurrence. It is not disputed that reach-through claims are more frequently encountered in biotech, but not exclusively.
Although boards are normally not referring to the Guidelines, as they are not bound by them, in the present case, the board made ample use of their content.
In T 544/12, the patent related to very high efficiency organic light emitting devices based on electrophosphorescence, wherein the emissive layer includes a molecule that is a phosphorescent organometallic iridium compound. The claim was of the reach-trough type.
The board held that not all conceivable compounds falling under the structural definition in claim 1 possess the claimed capability of being phosphorescent. The opposed patent did not contain any information as to how further phosphorescent iridium complexes, different from five disclosed structures, could be identified. Claim 1 was therefore nothing more than an invitation to perform a research programme to identify suitable iridium complexes.
In T 339/05, the application related to an ink composition for a meltable ink comprising an “amorphous solidifying monomer compound” fulfilling certain parameters. The board held that besides the disclosed examples, it needed a research program to find further amorphous solidifying monomer compounds.
When claiming a whole class of compounds, it is not sufficiency to throw in the description a few specific examples.
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