T 1977/22 - Open ended ranges for desirable properties

Key points

• Claim 1: "1. An inorganic composite oxide material, comprising: (a) from 25 to 90 pbw [parts by weight] Al2O3; (b) from 5 to 35 pbw CeO2; (c)(i) from 5 to 35 pbw MgO, [...] and (d) optionally up to 10 pbw of a combined amount of oxides of one or more dopants selected from transition metals, rare earths, and mixtures thereof, and exhibiting a BET specific surface area: of greater than 150 m**(2)/g"
• In the technical field, a high specific surface area (high porosity) is a desired property.
• T 595/90 (Kawasaki steel) is well known (in the chemistry field, especially for materials) for its headnote that " A product which can be envisaged as such with all the characteristics determining its identity including its properties in use, i.e. an otherwise obvious entity, may become non-obvious and claimable as such, if there is no known way or applicable (analogy) method in the art to make it and the claimed methods for its preparation are the first to achieve this and do so in an inventive manner ". 
• Incidentally, the headnote is obiter in T 696/90 as the preparation method was found to be obvious, the product claim accordingly as well, and the patent was revoked.
• The present Board: "When an invention is defined in terms of a desideratum, sufficiency of disclosure is generally assessed on the basis of the principle of reproducibility over the whole scope, which was proposed and developed in a number of early landmark decisions (see in particular T 435/91, T 292/85, T 226/85, T 409/91, and G 1/03)."
• The Board provides a useful review of the existing case law on the topic.
• "The most controversial aspect in the underlying discussion is the burden to be applied for determining whether the information at hand would enable the skilled person to reproduce the open-ended range over the whole scope of the claim, in particular because the interpretation of the concept "over the whole scope" is not straightforward when applied to a range with no specific upper limit. 
• " In summary, the board considers that the key criterion for enabling a technically challenging open-ended range desideratum over the whole scope of the claim is the provision of teachings demonstrating that, by operating within the scope of specific (essential) structural and/or process features, the skilled person would be in a position to achieve multiple variants of the invention without undue effort i.e. embodiments with different parametric values falling within the open-ended range. If this condition is met, an invention that defines both the open-ended range desideratum and the essential structural and/or process features required to achieve it may, in principle, be considered reproducible over the whole scope (at least with regard to the reproducibility of the open-ended range itself), irrespective of how far the numerical values can be extended beyond the lower end of the open-ended range. "
• Not sure if this means that three examples at 151, 152 and 154 m**(2)/g are sufficient to support the entire range "at least 150 m**(2)/g".
• The Board: "While it might have been open to discussion whether the process proposed for producing the composite oxide (or at least certain steps thereof) should also be considered an essential aspect of the invention (i.e. necessary to achieve parametric values within the open-ended range) and thus defined in the claim, the opponent explicitly stated that its argumentation did not rely on this point. The board also found no justification for introducing this argument ex officio."
• "Since the composite oxide in claim 1 at issue does not only define the open-ended range desiderata but also the above mentioned structural features (i.e. the metal oxide components and their amounts) considered to be essential for achieving parametric values within the claimed range, the board concludes that the open-ended ranges desiderata defined in claim 1 at issue are enabled by the teachings in the patent and that the invention is reproducible over the whole scope of the claim."
• To approach the matter from a different angle, if the claim had defined the composition only in terms of the chemical composition, such a product claim could have been perfectly fine and would not be limited to any particular range for the specific surface area. This aspect of product claims is not entirely free from criticism in the literature but is uncontroversial in the case law of the EPO. 
• Furthermore, under T 595/90, it is fine to have the desirable property as the distinguishing feature of the product claim. 

The link to the decision can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t221977eu1