T 2076/13 - Remittal and own motion

Key points

• In this opposition appeal, both opponents withdrew their opposition. The Board finds the claimed to be sufficiently disclosed. The Board remits the case to the OD, because the EPO may continue the opposition of own motion and because the main purpose of appeal proceedings is to review decisions of departments of first instance.
• There is also a discussion of a parameter feature. " [The] skilled person would be able to identify without undue burden the temperature at which the surface tension and the contact angle are to be measured. For this reason alone, the Board cannot come to the same conclusion as the opposition division that the patent does not meet the requirement of sufficiency of disclosure ". The Board agrees with the rationale of decisions such as T 593/09 and T 608/07.

EPO T 2076/13 -  link

3.3 Regardless of the considerations set out above, the Board observes that deficiencies arising from the presence in a claim of an ambiguously defined parameter or a parameter that could be measured by different methods or under different conditions leading to different values do not necessarily result in a problem of insufficiency of disclosure.

On this issue, in T 593/09 the board held that "[w]hat is decisive for establishing insufficiency within the meaning of Article 83 EPC is whether the parameter, in the specific case, is so ill-defined that the skilled person is not able, on the basis of the disclosure as a whole and using his common general knowledge, to identify (without undue burden) the technical measures (eg selection of suitable compounds) necessary to solve the problem underlying the patent at issue" (Reasons, point 4.1.4).

Along the same line, in T 608/07 the board stated that "for an insufficiency arising out of ambiguity it is not enough to show that an ambiguity exists, eg at the edges of the claims. It will normally be necessary to show that the ambiguity deprives the person skilled in the art of the promise of the invention" (Reasons, point 2.5.2).

The same approach has been followed in various other decisions such as T 385/13 (Reasons, point 3.4.3) and T 1988/13 (Reasons, point 1.2).

Furthermore, in a number of decisions the boards have held that when the presence of an ill-defined parameter merely generates some uncertainty in the definition of the boundaries of the claim, with the effect that the skilled person would not know whether he is working within or outside the scope of the claims, there is normally a problem of clarity rather than insufficiency (see e.g. T 593/09 and T 608/07, supra, T 2290/12, Reasons, point 3.1 and T 1414/08, Reasons, point 8).

This Board agrees with the rationale of these decisions.

3.4 In the present case the opponents have not produced any evidence or a convincing argument that, as a consequence of the alleged deficiency in the definition of the surface tension and of the contact angle, the skilled person would be deprived of the promise of the invention because he would not be able to select the appropriate infiltrants. In this respect the Board observes that paragraphs [0019] and [0020] of the patent provide general information on the composition of the infiltrants and Table 2 discloses several specific examples of suitable infiltrants.

There is furthermore no evidence that, in the present case, variations in the temperature at which the surface tension and the contact angle are measured have a major impact on the value of the penetration coefficient. The opponents referred in this regard to a passage of D23 (paragraph bridging pages 45 and 46) according to which, in a study dating back to 1975, it was observed for a specific infiltrant that the penetration coefficient at 37°C was 2.5 times greater than the value determined at 25°C. In this regard the Board notes that the same passage explains that this effect was mainly due to the diminution of the viscosity with the increase in temperature. However in the present case the viscosity is to be determined at a fixed temperature, namely 25°C. Thus, D23 does not indicate that measuring the surface tension and the contact angle at different temperatures results in strong variations in the penetration coefficient.

Moreover, Table 1 of the experimental report submitted by the appellant (document D101) shows that there is minimal variation in the surface tension in the range 20° to 37°C. As to the contact angle, the Board observes that paragraph [0074] of the patent explains that variations in its value have a limited impact on the penetration coefficient as, in accordance with the formula in claim 1, the contact angle affects the penetration coefficient only proportionally to its cosine. Furthermore, document D22 shows that in some acrylic resins containing the same monomers as the resins listed in table 2 of the patent, the cosine of the contact angle is approximately inversely proportional to the surface tension (page 179, paragraph "Contact angle", and Figure 3). As both the surface tension and the cosine of the contact angle are multiplied in the numerator of the formula in claim 1 any variations in their values would tend to cancel each other out so that the combined influence on the penetration coefficient of the contact angle and the surface tension at varying temperatures would be very limited.

3.5 In summary, on the basis of the evidence and arguments submitted by the parties, the Board considers that variations in the measured values of the surface tension and of the contact angle would have a limited impact on the value of the penetration coefficient. This could possibly affect the precise definition of the boundaries of claim 1 with the consequence that it may be difficult to establish whether a given infiltrant is encompassed or not by the definition of component b) of claim 1. However, this issue does not relate to the assessment of sufficiency of disclosure.

3.6 As discussed in point 3.4 above, the description provides sufficient information on selecting the components of the infiltrant and example 3 discloses a method for its preparation. The other component of the kit of claim 1 is a conditioner based on a gel containing 5% hydrochloric acid. The Board sees no reason why a skilled person would not be able to prepare such a product.

Hence, the Board considers that the skilled person would be able to carry out the invention defined in the patent in suit. The requirement of sufficiency of disclosure is therefore met.

4. Remittal

4.1 Both opponents withdrew their oppositions in the course of the appeal proceedings (see point VII above). Pursuant to the second sentence of Rule 84(2) EPC, after withdrawal of the opposition(s) the EPO may continue the opposition proceedings of its own motion.

4.2 The main purpose of appeal proceedings is to review decisions of departments of first instance. In the decision under appeal only the grounds for opposition pursuant to Article 100(b) and (c) EPC have been considered whereas the grounds of novelty and inventive step have not been dealt with. Under these circumstances the Board deems it appropriate to remit the case to the opposition division in order for it to decide whether to continue or close the opposition proceedings, pursuant to Rule 84(2) EPC.