T 0764/14 - Sufficiency of parameter

Key points

• " Any "errors" possibly associated to the procedures implied or described in the patent in suit for measuring the surface Na baseline and the % of surface Na removed, do not prevent the skilled person from carrying out all those embodiments of the claimed process wherein the measured amount of Na in the pretreatment solutions is well above 25% of the measured Na baseline, [which] certainly comply with requirement (A)." 
• The Board thus holds that the ambiguity deriving from such possibly unavoidable but limited "errors" does not "permeate the whole claim" and hence does not "deprive the skilled person of the promise of the invention" in the sense of e.g. decision T 0608/07 [].

EPO T 0764/14 - link

Reasons for the Decision

Main Request - Sufficiency

[...] 3.3.3 Hence, for the Board, at least in all those embodiments of the claimed process in which the (overall) amount of Na ions found in the pretreatment solutions is well above 25% of the measured surface Na baseline (possibly slightly higher than the actual amount of surface Na in the untreated carrier), the fraction of this amount that actually derives from surface Na must also inevitably be above the 25% of the actual amount of surface Na present in the untreated carrier. In other words, any "errors" possibly associated to the procedures implied or described in the patent in suit for measuring the surface Na baseline and the % of surface Na removed, do not prevent the skilled person from carrying out all those embodiments of the claimed process wherein the measured amount of Na in the pretreatment solutions is well above 25% of the measured Na baseline, certainly comply with requirement (A).

The Board thus holds that the ambiguity deriving from such possibly unavoidable but limited "errors" does not "permeate the whole claim" and hence does not "deprive the skilled person of the promise of the invention" in the sense of e.g. decision T 0608/07 of 27 April 2009, Reasons, 2.5.2).

3.3.4 Already for this reason, the Board concludes that based on the information contained in the patent in suit the skilled person is in the position to carry out, without undue burden, embodiments of the claimed process wherein the conditions applied in step "(i)" are such that requirement (A) is met.

3.4 For the sake of completeness, the Board nevertheless considers it appropriate to additionally comment the case of a skilled person seeking to carry out processes according to the invention at the borderlines of requirement (A) of claim 1, in which the % of surface Na removed is either exactly 25% or slightly above this value.

3.4.1 This particular case was considered in the decision under appeal (Reasons, 2.4.1.9 and 2.4.1.10). The Department of First Instance concluded that the disclosure in the patent did not allow to carry out such processes (Reasons, 2.4.1.12 in combination with 2.6).

3.4.2 The Board finds instead that the above-discussed possible "errors" originating from the dissolution of subsurface Na during the "Acid-Leachable test" and during the actual pretreatment, do not make it impossible to actually carry out (technically speaking) processes at the borderlines of requirement (A). They might at most make it impossible to come to an unambiguous conclusion as to whether or not such processes (that can be carried out and for which the measured amount of surface Na removed is 25% or just above about 25%) are embodiments of the claimed process, i.e. whether they fall within the ambit of claim 1. Thus, these "errors" would at most give to issues of clarity (Article 84 EPC) regarding the exact boundaries of the claim. However, since this issue is not caused by a post-grant amendment it is not relevant in the present opposition/appeal proceedings (G 3/14, OJ 2015, A102, Order).

7. Undue burden in terms of experimental work required - requirements A , B and C in combination

7.1 Finally, according to the Respondent, the absence of clear technical definitions and indications as to requirements A, B and C imposed an undue burden on the person skilled in the art seeking to reproduce the claimed invention. In particular, based on a number of complex technical considerations he had to carry out extensive experimental work, prior to be able to repeat the claimed process. Thus, the invention had not been sufficiently disclosed.

7.2 The Board acknowledges that the explicit technical disclosure of the patent in suit lacks the desirable precision under some aspects.

7.2.1 However, as set out above, the Board holds that the person skilled in the art would not be confronted with particular difficulties when seeking to identify the appropriate temperature and length of time for the "Acid-Leachable test" that allow to determine with sufficient certainty the surface Na baseline.

7.2.2 Moreover, the patent in suit contains valuable technical information and guidance as to the nature of suitable carrier materials (paragraphs [0027], [0051], [0052] and [0072]), as well as of suitable Li salts and their concentrations (paragraph [0036] and examples).

7.2.3 Thus, the Board is also convinced that the person skilled in the art is able to identify, among commercially available low-sodium carriers based on alpha-alumina with silicate on its surface, suitable starting materials having, for instance, a surface Na baseline comparable to those reported in Table 1. Also suitable Li salt solutions (e.g. similar to those used in the examples) can be provided without difficulty.

7.2.4 The remaining instructions contained in the patent in suit (in particular those in paragraphs [0031] to [0039]) further suggest to the skilled person (who would also be aware of the possibly unavoidable but limited contribution of subsurface species to any measure to be made when checking compliance with requirements (A) to (C)) to perform, inter alia, the following operations:

i) monitoring, by conventional analytical means, the amount of Na, Li and Si in the aqueous phase during the treatment with aqueous Li salt solution(s) (of known starting Li content), and carrying out such treatment at a temperature sufficiently below 100°C and for a length of time that allow to obtain an amount of Na in the Li salt solution well above 25% of the surface Na baseline, but still ascertaining that that amount of removed Si remains well below 5 times that of the removed Na, and then

ii) carrying out washing with water of the carrier while monitoring the amount of Na, Li and Si in the wash water phase(s), so as to achieve sufficient removal of Li contamination (i.e. leaving in the pretreated carrier a amount of Li which is clearly less than 10 ppm), but not to continue such washing so long that too much of the Si is removed (i.e. so as to still keep the removed Si/Na ratio clearly below 5).

7.3 In the absence of any evidence to the contrary, the Board sees no reason for considering that the person skilled in the art would experience serious difficulties in performing any of the above operations. Thus, the Board has no reason to consider that an undue amount of experimental work is needed to carry out many different embodiments of the claimed processes across the breadth the claim that certainly comply with the requirements given for step "(i)".

Moreover, carrying out specifically those processes for which the measured % of removed surface Na is very close to 25% and/or the measured surface Li is very close to 10 ppm and/or the measured removed Si/Na ratio is very close to 5, does not involve any undue burden of experimental work, but only generates doubts as to whether or not such processes at the borderlines of the invention as defined in claim 1 actually fall within the ambit of claim 1.

8. Hence, in the Board's judgement, the invention as defined in claims 1 to 3 of the Main Request is disclosed in the patent in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. The requirements of Article 83 EPC are thus met.

9. Remittal of the case

Since the decision under appeal only addressed the ground of opposition of Article 100(b) EPC, the Board considers it appropriate to remit the case to the Opposition Division pursuant to the provisions of Article 111(1) EPC, in accordance with the corresponding requests of both Parties.

Order

For these reasons it is decided that:

- The decision under appeal is set aside.