Monday 15 October 2018

T 0435/91 - Sufficiency of disclosure over the whole area claimed - #26

Citation rank: 26
No. of citations: 140

T 435/91 is concerned with the question of sufficiency of disclosure in cases where the invention relates to a chemical composition and is, in part, defined by functional features. T 435/91 holds that sufficiency of disclosure is not given, if the patent discloses only isolated examples falling under the functional definition of the claim, but does not disclose a technical concept fit for generalisation so that the skilled person can achieve the envisaged result without undue difficulty within the whole ambit of the claim containing the functional definition.

Claim 1 of the underlying opposition case related to:
"An aqueous detergent composition comprising a gel, characterised in that the gel is wholly or predominantly in hexagonal liquid crystal form, and comprises:
(a) [...]
(b) an additive which is a water-soluble non-micelle-forming or weakly micelle-forming material capable of forcing the surfactant system (a) into hexagonal phase, the additive being nonionic or of the same charge type as the surfactant (a)(i); and
(c) [...]"
There was no dispute that the skilled person could establish whether or not a detergent composition was in a hexagonal form or not. Furthermore, it was not disputed among the parties that the worked examples in the description of the patent were feasible. Thus it is clear that the patent discloses at least one way to carry out the invention and that it is possible to determine whether or not any particular composition meets the definition of the invention as set out in claim 1.

There was, however, dispute as to whether or not the subject matter of claim 1 could be carried out by skilled person, because one of its essential technical features, the "additive" (b), was defined only by its function.

Regarding the requirement for sufficient disclosure of structurally vs. functionally defined inventions, the Board stated:
"In the board's judgment, the criteria for determining the sufficiency of the disclosure are the same for all inventions, irrespective of the way in which they are defined, be it by way of structural terms of their technical features or by their function. In both cases the requirement of sufficient disclosure can only mean that the whole subject-matter that is defined in the claims, and not only a part of it, must be capable of being carried out by the skilled person without the burden of an undue amount of experimentation or the application of inventive ingenuity." (point 2.2.1 of the reasons, emphasis added)
The Board thus held that the disclosure relating to both, functionally and structurally defined inventions, must be such that the skilled person can carry out the invention over the entire scope of what is claimed.

Regarding the special case of functionally defined inventions, the Board held:
"The peculiarity of the "functional" definition of a component of a composition of matter resides in the fact that this component is not characterised in structural terms, but by means of its effect. Thus this mode of definition does not relate to a tangible component or group of components, but comprises an indefinite and abstract host of possible alternatives, which may have quite different chemical compositions, as long as they achieve the desired result. Consequently, they must all be available to the skilled person if the definition, and the claim of which it forms a part, is to meet the requirements of Article 83 or 100(b) EPC. This approach is based on the general legal principle that the protection covered by a patent should correspond to the technical contribution to the art made by the disclosure of the invention described therein, which excludes the patent monopoly from being extended to subject-matter which, after reading the patent specification, would still not be at the disposal of the skilled person (see also points 3.4 and 3.5 of decision T 409/91, OJ EPO 1994, 653)." (point 2.2.1 of the reasons, emphasis added)
The Board thus  investigated whether in the case at hand, the description contained sufficient information to fulfil the above requirement for sufficient disclosure. In this respect, the patentee had admitted during the oral proceedings that it was not possible to identify, on the basis of the information contained in the patent, other compounds than those specifically mentioned in the description, which could reasonably be expected to bring about the desired effect defined in feature (b).

The Board concluded that the definition of the "additive" in feature (b) amounted more to an invitation to launch a research program than to a clear definition of a feature of the claimed detergent composition.

Therefore, the Board held that the invention defined in claim 1 was not sufficiently disclosed.

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Headnote:
The disclosure of an invention relating to a composition of matter, a component of which is defined by its function (in the present case an additive which forces a detergent composition into the hexagonal liquid crystal phase), is not sufficient if the patent discloses only isolated examples, but fails to disclose, taking into account, if necessary, the relevant common general knowledge, any technical concept fit for generalisation, which would enable the skilled person to achieve the envisaged result without undue difficulty within the whole ambit of the claim containing the "functional" definition (point 2.2.1 of the reasons).
The full text of the decision can be found here.

Quotes from decisions citing T 435/91 can be found here.

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