Zusammenfassung von EPC2000 Art 056 für die Entscheidung T2716/19 vom 10.01.2024

In T 2716/19 it was common ground that the subject-matter of claim 1 of the main request differed from disclosures in D1, D5 and D15 only in that magnesium t-butyl oxide or magnesium isopropyl oxide was used in lieu of lithium t-butoxide. However, the views of the parties diverged on the technical effect deriving from this distinguishing feature. The respondent (patent proprietor) argued that example 1b of the application as filed demonstrated an improvement in the yield in the reaction of HPA to PMPA when magnesium t-butyl oxide or magnesium isopropyl oxide was used as the base instead of lithium butoxide. This improvement was confirmed by each of the post- published documents D18 to D21 and D24. The appellant (opponent 2) contested the presence of any technical effect associated with the distinguishing feature. Firstly, it argued that the application as filed did not make the above-mentioned technical effect brought forward by the respondent plausible. The application as filed did not include any evidence that the claimed bases would result in an improved PMPA yield. It argued that not only was there no absolute proof, there was no evidence whatsoever in the application as filed of any improved yield. Moreover, the respondent had not relied on common general knowledge for justifying the alleged technical effect. It argued the opposition division was incorrect to allow the respondent to rely on post-published evidence. The board was not convinced by this line of argument. Decision G 2/21 states (point 1 of the Order) that "[e]vidence submitted by a patent applicant or proprietor to prove a technical effect relied upon for acknowledgement of inventive step of the claimed subject-matter may not be disregarded solely on the ground that such evidence, on which the effect rests, had not been public before the filing date of the patent in suit and was filed after that date". The skilled person would have immediately recognised an improvement in the yield of the desired product, here PMPA, as a fundamental objective of the disclosed method. It held that the improvement of the PMPA yield in a reaction starting from HPA by using the alkoxides defined in the current main request relied on by the respondent was encompassed by the technical teaching and embodied by the invention originally disclosed in the application as filed. In line with the Order in G 2/21, this technical effect could thus be relied on by the respondent, and post-published evidence confirming this technical effect could not be disregarded. The board was also not convinced by the appellant's other lines of argument and held that when starting from D1, D5 or D15, the objective technical problem should at least be seen as the provision of a method achieving an improved yield of PMPA. The skilled person facing this objective technical problem would not have been prompted by any available document or common general knowledge to replace the lithium-t-butoxide used in the method of the closest prior art with either magnesium t-butyl oxide or magnesium isopropyl oxide as required by claim 1 of the main request. The subject-matter of claim 1 of the main request thus involved an inventive step within the meaning of Art. 56 EPC.