T 0316/93 01-10-1997

1. The appeal is admissible.

2. The present decision is based on the following text of the application in suit:

Claims:

1. to 17 filed on 15 September 1997 (letter dated 10 September 1997);

Description:

pages 1, 2, 4, 5, 8 to 26 as originally filed;

pages 6, 7 filed on 5 December 1991 (letter dated 4 December 1991);

pages 3, 3a filed on 15 September 1997 (letter dated 10 September 1997).

3. Amendments; Article 123(2) EPC

Claims 1 to 17 differ from previous Claims 1 to 17 of the main request underlying the decision under appeal in the following respects:

3.1. The phrase "Use....in dental treatment to make dental impressions" in previous Claim 1 has been replaced by "Use, as a dental impression material". This is supported by the description on page 1 at lines 11, 12.

3.2. The references to "said dental treatment" in previous Claims 2 to 9 have been deleted. This is in conformity with the amendment in Claim 1.

3.3. The reference to "one-part silicones" has been deleted from previous Claim 10. This is the simple deletion of one independent option.

3.4. The features of the ionisation constants of the cationic and amphoteric surfactants have been inserted in Claims 1 and 10. This is supported by the originally filed description on page 10, lines 28 to 35.

3.5. The wording of Claims 9 and 17 has been amended to render them fully consistent with the relevant antecedent claims.

3.6. The corresponding passages of description have been adapted to the revised claims. No objection under Article 123(2) EPC was raised in respect of the claims of the main request underlying the decision under appeal or to the corresponding description. The Board sees no reason to raise an objection of its own under this heading. Nor do the amendments effected subsequently (sections 3.1 to 3.5, above) comprise added matter.

3.7. Consequently, the amendments to Claims 1 to 17 and to the description are acceptable under Article 123(2) EPC.

4. Amendments; Article 52(4) EPC

The use, as a dental impression material, of a room temperature vulcanizing silicone composition as defined in Claims 1 to 9 does not amount to a process leading to the amelioration or elimination of a medical deficiency or disease. On the contrary, it is rather to be seen as a process of using the relevant part of a human body, i.e. the dentition, as a moulding tool, to obtain a moulded impression, which is itself a product having commercial value. It is not, therefore, a treatment of the human or animal body in the sense of the exception to patentability set out in Article 52(4) EPC.

Consequently, the amended claims are acceptable under Article 52(4) EPC.

5. Clarity

The issue in this appeal is whether the objections in the decision under appeal to the clarity of the features (A) "three minute water contact angle" and (B) "the surfactant being capable of migration throughout the cured silicone composition and into adjacent fluids" are justified in law.

5.1. Feature (A)

Closer examination of the decision under appeal (section III., above) shows that, whereas the feature found to lack clarity is an overall characteristic of the cured silicone composition ("three minute water contact angle"), the deficiency alleged in its definition resides exclusively in features of the surfactant (the number of ethylenoxy and propylenoxy groups as well as the remaining substituent groups present). The surfactant, however, is merely a sub-component of the still curable composition. Whilst the nature of the surfactant may affect the value of the three minute water contact angle, it cannot affect the clarity of the definition itself, since the latter is independent of the surfactant used. Consequently, the reasoning does not support the objection.

5.1.1. On the contrary, the definition of the three minute water contact angle itself is, in the Board's view, extremely precise; more precise, even, than the closely related parameter "equilibrium water contact angle", since it specifies with mathematical precision the time after wetting at which the measurement must be taken.

5.1.2. Yet the "equilibrium contact angle" has itself been convincingly shown, by reference to a standard treatise: Walter Noll, "Chemistry and Technology of Silicones", Academic Press, 1968, pages 447 to 452, to have been a term well-known in the art at the filing date (submission filed on 6 March 1991). Even if this had not been the case, the reference is itself specifically cited in the application in suit (page 5). Thus the term "three minute contact angle", which differs only in the point in time at which the measurement is taken, cannot be regarded as "unusual" in the sense of rendering the claim unclear.

5.1.3. Nor has any contradiction or uncertainty in the method of measuring the relevant contact angle been alleged. On the contrary, the method of measurement is set out in the reference (section 5.1.2, above).

5.1.4. The question of whether or not such a form of definition is justified in the present case is not an issue of clarity, or even of support, but of sufficiency (see decision T 0435/91, OJ EPO 1995, 188; Reasons for the decision, points 2.2.1 to 2.2.3).

5.1.5. Consequently, the Board is unable to support the objection of lack of clarity raised against feature (A).

5.2. Feature (B)

The objection to the insertion of the feature of "the surfactant being capable of migration throughout the cured silicone composition and into adjacent fluids", according to the decision under appeal, is based primarily on an allegation that it is not credible that the effect referred to is actually produced (Reasons for the decision, paragraph 4). Even if such an allegation were justified, it does not amount to a demonstration that the feature is unclear. Thus, the reasoning does not support the objection.

5.2.1. It is, however, clear from the explanation given in the description, that the surfactant is believed to be capable of migration (page 6, lines 6 to 9). It goes without saying, in this connection, that an Applicant or Patentee is under the greatest obligation of good faith in the presentation of his invention.

5.2.2. Furthermore, this belief is evidently not subjective, but based on objective data, in particular the scientific observations that:

(a) the measured water contact angle increases if a cured composition is immersed in running water for a period of time (page 6, lines 3 to 5); and

(b) the measured water contact angle slowly changes after the drop is placed on the surface of the cured silicone; if the drop is observed using an optical comparator, schlieren patterns become visible at the interface between the drop and the silicone within a few seconds after the drop is applied; after this, the schlieren patterns diffuse through the drop and the drop slowly collapses and spreads out on the surface of the silicone (page 6, lines 15 to 25).

Such observations are considered to amount to experimental data, the veracity of which has not been challenged, and which the Board has no reason to doubt.

5.2.3. The finding in the decision under appeal, that there is no evidence for the alleged effect in the examples, cannot be regarded as conclusive, since the criterion to be applied in the assessment of evidence is its objective credibility, rather than whether it appears in one or another part of the description.

5.2.4. In the present case, however, the Board cannot concur even with the factual basis of the finding, since there is indeed relevant evidence in the examples. In particular, the results of the eleven runs of Example 1 (Table I) and the fifteen runs of Comparative Example 1 (Table II) each give two different values of the contact angle, showing a reduction with the passage of time.

5.2.5. In any case, no reason is given in the decision under appeal which would amount to a rational basis for doubting the existence of the effect in the first place. In particular, the unbound nature of the surfactants, i.e. that they are not disclosed as being reactive with the curable silicone so as to become immobilised as part of the cured silicone structure, renders the disclosure of such a capability, in the Board's view, entirely credible.

5.2.6. As to the question of whether the same effect occurs in the prior art, this is irrelevant to the question of clarity of the feature claimed.

5.2.7. In summary, all the indications in the application in suit, whether from the description on page 6 or from the examples themselves, as well as general considerations relating to the unbound nature of the surfactants, point to the credibility of the effect associated with feature (B). Consequently, the Board cannot support the allegation, in the decision under appeal, upon which the objection of lack of clarity was primarily based.

5.2.8. The second aspect of the objection to feature (B), namely that it is functional in character does not itself render the term unclear. Since, furthermore, it has not been alleged that the definition of feature (B) is otherwise obscure in itself, its presence cannot contribute to any lack of clarity in the claims.

5.2.9. As regards the cumulative effect of the functional feature (A), the latter has already found to be free of the deficiency alleged in the decision under appeal (section 5.1.4, above).

5.2.10. Consequently, the Board cannot support the finding, in the decision under appeal, of lack of clarity in the sense of Article 84 EPC, in relation to feature (B).

6. Lack of clarity (Article 84 EPC) was, however, the sole ground of refusal of the application. Consequently, the appeal must succeed.

7. To order the grant of a patent would, however, be premature, since it is evident that the substantive examination of the application, in particular with regard to novelty and inventive step, has not been completed. Consequently, the Board intends to make use of its powers under Article 111(1) EPC, to remit the case to the Examining Division, for further examination.