T 2916/19 - Scientific paper is invalid prior art

Key points

• D1 is "Uehara et al., Structural characterization of ultrahigh-molecular-weight polyethylene reactor powders based on fuming nitric acid etching, Polymer, 1998, vol. 39, number 24, pages 6127- 6135;"
• "the respondent [patentee] was of the opinion that samples 1, 3 and 5 of E1 did not belong to the state of the art because E1 did not constitute an enabling disclosure as to how to (re)produce [the polymer] samples without undue burden"
• " it is however unclear to the Board why and on which basis the opposition division held that "the lack of enablement of a prior art document should not be contested/discussed in opposition proceedings"
• "it is established case law that a disclosure can only be regarded as having been made available to the public, and therefore as comprised in the state of the art pursuant to Article 54(2) EPC, if the information given therein to the skilled person is sufficient to enable them, at the relevant date of the document, to practise the technical teaching which is the subject of the document, taking into account also the general knowledge at that time in the field to be expected of him"
• "the question arose whether or not the skilled person would be able to prepare without undue burden any of samples 1, 3 and 5 of E1 in view of the very limited information provided in E1 regarding their preparation process, in particular regarding the catalyst system used,"
• " the [opponent] argued that E1 was a scientific publication which had been subjected to peer review and that D16 showed that E1 had been cited in numerous other publications articles"
•  "However, the fact that E1 was cited several times in subsequent scientific articles constitutes no evidence that the skilled person was in the position, at the priority/filing date of the patent in suit, to prepare samples 1, 3 and/or 5 in a reliable manner on the basis of the teaching of E1, if needed complemented by common general knowledge. In particular, it was not shown that said samples 1, 3 and 5 were effectively prepared in any of the publications citing E1. To the contrary, the respondent showed with D17 that the reference to E1 in at least one of these publications was not even related to the preparation of said samples"
• "according to established case law, each party bears the burden of proof for the facts it alleges (Case Law, supra, III.G.5.1.1). In the present case, the Board considers that since the appellant/opponent raised objections based on the disclosure of samples 1, 3 and 5 of E1, the burden of proof primarily resides on them to show that said samples of E1 effectively belong to the state of the art for the patent in suit. 
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• After further analysis, the Board concludes that "In view of the above, the disclosure of E1 is not sufficient for the skilled person to be able to prepare reliably any of samples 1, 3 and 5 as disclosed therein."
   

EPO 

The link to the decision is provided after the jump, as well as (an extract of) the text of the decision.

https://www.epo.org/law-practice/case-law-appeals/recent/t192916eu1.html

Reasons for the Decision

Main request

1. The operative main request is identical to the main request dealt with in the decision under appeal and allowed by the opposition division.

2. Objections based on E1 - Enabling disclosure

2.1 The appellant raised objections of lack of novelty and of lack of inventive step against claim 1 of the main request, which were all based on samples 1, 3 and/or 5 of document E1. It was not in dispute between the parties that document E1 was published before the priority/filing date of the patent in suit. However, the respondent was of the opinion that samples 1, 3 and 5 of E1 did not belong to the state of the art because E1 did not constitute an enabling disclosure as to how to (re)produce said samples without undue burden (rejoinder: points 36 to 46; see also letter of 6 July 2021: page 8, first paragraph to page 10, first paragraph). Therefore, it has to be assessed if E1 constitutes an enabling disclosure for the ethylene polymer particles prepared therein as samples 1, 3 and/or 5.

2.2 In that respect, it is noted that such an objection was already put forward during the opposition proceedings but that the opposition division did not deem necessary to deal with it (decision under appeal: paragraph bridging pages 11 and 12). The opposition division further indicated that "the new argument was admitted into the procedure" (minutes of the oral proceedings held on 6 June 2019: page 2, sixth paragraph; see also the decision under appeal: page 12, end of second paragraph). In this regard, it is however unclear to the Board why and on which basis the opposition division held that "the lack of enablement of a prior art document should not be contested/discussed in opposition proceedings" (decision under appeal: page 12, second paragraph, first sentence; see also section 46 of the rejoinder).

2.3 Regarding the issue of enabling disclosure, it is established case law that a disclosure can only be regarded as having been made available to the public, and therefore as comprised in the state of the art pursuant to Article 54(2) EPC, if the information given therein to the skilled person is sufficient to enable them, at the relevant date of the document, to practise the technical teaching which is the subject of the document, taking into account also the general knowledge at that time in the field to be expected of him (Case Law of the Boards of Appeal of the EPO, 10th edition, 2022, I.C.4.11).

2.3.1 In that regard, it was common ground that document E1 deals with the preparation of ultrahigh molecular weight polyethylene particles (UHMW-PE), which are prepared using "a high-activity Ziegler catalyst" at various temperatures (E1: page 6128: section EXPERIMENTAL/Materials; table 1; figure 1; page 6134: section CONCLUSIONS). In particular, reference is made in E1 to UHMW-PE particles prepared as samples 1 to 5 (table 1; figures 1 and 6-9; section "SEM observations, starting on page 6131). In that respect, the sole passages of E1 relied upon by the appellant regarding the preparation process of these samples is the

section EXPERIMENTAL/Materials on page 6128 of E1, which reads as follows:

"A series of nascent UHMW-PE reactor powders was prepared at the Nippon Oil Company Ltd. by the polymerization of ethylene in hexane at Tpoly = 20 - 90°C and at an ethylene pressure of 11 atm, using a high-activity Ziegler catalyst. The temperature of the reaction medium was taken as Tpoly. The viscosity-average molecular weight, Mv, of UHMW-PE was controlled by the addition of a small amount of hydrogen gas, depending on Tpoly. These samples had comparable Mv values of around 2 X 10**(6)."

2.3.2 Considering that E1 constitutes a written disclosure and not an alleged public prior use, the circumstances of the present case are not the same as the ones addressed in decisions G 1/92 (OJ EPO 1993, 377: see in particular the questions posed in section I) and T 1833/14 (reasons: section 1), which were both relied upon by the respondent (rejoinder to the statement of grounds of appeal: points 37-38). Nevertheless, the arguments put forward by the respondent are equally relevant for the written disclosure E1. Indeed, in view of the respondent's submissions, the question arose whether or not the skilled person would be able to prepare without undue burden any of samples 1, 3 and 5 of E1 in view of the very limited information provided in E1 regarding their preparation process, in particular regarding the catalyst system used, even taking into account common general knowledge (rejoinder to the statement of grounds of appeal: points 39-42 and 44-45 in section II).

2.3.3 Preparation of samples 1, 3 and 5 of E1

a) Regarding the question of the (re)production of samples 1, 3 and 5 of E1 and as indicated in the first paragraph of section 1.6 of decision T 1833/14, which is fully endorsed by the present Board, it is generally known in the field of polymers and it was not contested by the appellant that the nature of the catalyst system, the type of reacting system and the process conditions significantly affect the properties of the produced polymer. In particular, in the polymer field, in which products and compositions are often defined by means of parameters, the requirements of sufficiency of disclosure is analysed with particular care and is considered to be met in such cases if the application or the patent, when necessary supported by the common general knowledge, discloses the method of preparation of the polymers (in particular by means of the catalyst system, the type of reacting system and the process conditions) which results in products and compositions with the required parameters. The same criteria must therefore apply to the reproducibility without undue burden of a product disclosed in a written disclosure used as a prior art such as the disclosure related to samples 1, 3 and 5 of E1.

b) However, in the present case, the information provided in E1 regarding the preparation of samples 1, 3 and 5 is very limited (see citation in section 2.3.1 above). In particular, the sole information regarding the nature of the catalyst used is that it should be a "high activity Ziegler catalyst", which is a very broad definition encompassing a multitude of catalyst systems (in view of the absence of any further limitation of that disclosure regarding e.g. the nature of the active metal, the cocatalyst and/or catalyst support, if any).

c) However, it is derivable from the information provided in the patent in suit and from the evidence relied upon for the assessment of sufficiency of disclosure in decision T 231/15 (see in particular sections 3.4.1 and 3.4.2 of the reasons; it is reminded here that decision T 231/15 was taken in the first appeal related to the patent in suit) that the nature of the catalyst system and the mode of preparation thereof are crucial in order to obtain ethylene polymer particles satisfying specific parameters/having specific properties. For instance, comparative example 1 of the patent in suit is directed to the preparation of ethylene polymer particles using a catalyst similar to the one used in the examples of the patent in suit illustrative of the subject-matter claimed but failed to lead to polymers having a degree of crystallinity as defined in claim 1 of the main request (see table 1 as well as paragraphs 127, 128, 174 and 175 of the patent in suit). Under these circumstances, the fact that the skilled person may be aware from their common general knowledge that the nature of the catalyst system is crucial for the properties of the obtained polymers is not sufficient: what would be required in order to be able to (re)produce samples 1, 3 and 5 of E1 in a reliable manner is more precise information regarding the catalyst (and/or its preparation process, which was shown to be of importance in section 3.4.2 of T 231/15) effectively used. Therefore, the appellant's argument that the skilled person would be aware that the choice of internal donor and its amount/ratio to titanium was crucial cannot overcome the lack of information provided in E1 in that regard (appellant's letter of 20 March 2023: page 5, fourth paragraph).

d) In the Board's view, the reference to common general knowledge in the present technical field regarding the importance of the nature of the catalyst system indicated in section a) above together with both comparative example 1 of the patent in suit and the evidence relied upon for the assessment of sufficiency of disclosure in decision T 231/15 indicated in section c) above constitute serious doubts substantiated by verifiable facts supporting the objection of lack of enablement raised by the respondent against samples 1, 3 and 5 of E1. Therefore, the appellant's concerns in that regard are not persuasive (letter of 20 March 2023: page 4, last two paragraphs).

e) It was also not shown by the appellant that the skilled person would know from common general knowledge how to complement the information of E1 in order to prepare samples 1, 3 and 5 of E1 as disclosed therein with a good chance of success.

f) Furthermore, it was also not shown that said - missing - information was available to the public.

f1) In that regard, the appellant argued that E1 was a scientific publication which had been subjected to peer review and that D16 showed that E1 had been cited in numerous other publications articles (letter of 20 March 2023: bottom of page 3 to middle of page 5). This showed that the content of E1 was correct and enabled, so the appellant.

However, the fact that E1 was cited several times in subsequent scientific articles constitutes no evidence that the skilled person was in the position, at the priority/filing date of the patent in suit, to prepare samples 1, 3 and/or 5 in a reliable manner on the basis of the teaching of E1, if needed complemented by common general knowledge. In particular, it was not shown that said samples 1, 3 and 5 were effectively prepared in any of the publications citing E1. To the contrary, the respondent showed with D17 that the reference to E1 in at least one of these publications was not even related to the preparation of said samples (respondent's letter of 12 April 2023: points 16-18).

f2) During the oral proceedings before the Board, the appellant argued that, if necessary, the skilled person could always have asked the authors of E1 for any missing information regarding the preparation of samples 1, 3 and 5.

However, that argument is not supported by any evidence and, since it relates to information which was not shown to be made available to the public before the relevant date, is purely speculative. Therefore, it is rejected already for that reason.

f3) Considering that even if, to the appellant's benefit, their arguments based on D16 were to be admitted into the proceedings, they would be rejected by the Board for the reasons given above, there is no need for the Board to decide on the admittance of D16 and of the appellant's submissions based thereon, which was objected to by the respondent (letter of 12 April 2023: point 11). The same is valid regarding D17, which is a document cited in D16 and which was filed by the respondent in reaction to the filing of D16.

h) In view of the above, the disclosure of E1 is not sufficient for the skilled person to be able to prepare reliably any of samples 1, 3 and 5 as disclosed therein.

i) It is further noted that in the present case, the appellant argued in respect of sufficiency of disclosure that, even with knowledge of the information provided by the patent in suit regarding the preparation process the skilled person would not have enough guidance in order to prepare in a reliable manner a UHMW-PE having specific properties. However, the information provided by the patent in suit is much more detailed than the one of E1: not only does the patent in suit contain general information, in particular regarding the catalyst system, but it also provides various teachings regarding preferred components and options as well as five examples illustrating the subject-matter being claimed, which includes a detailed description of the preparation of the catalyst system used (see section 3.2 of the reasons of T 231/15 and paragraphs 127-128 of the patent in suit). Therefore, in the present case, it is agreed with the respondent (rejoinder: points 39-42) that the line of argumentation provided by the appellant in respect of sufficiency of disclosure of the patent in suit (even if it was eventually not successful: see section 3 of the reasons of T 231/15) confirms the conclusion reached in section h) above.

2.3.4 Burden of proof

a) It was in dispute between the parties whether the burden of proof regarding enablement of samples 1, 3 and 5 of E1 was on the appellant/opponent or on the the respondent/patent proprietor (see e.g. appellant's letter of 2 March 2021: page 9, penultimate paragraph; respondent's letter of 6 July 2021: paragraph bridging pages 9 and 10; the arguments were further developed in subsequent written submissions and at the oral proceedings before the Board).

a) In that respect, according to established case law, each party bears the burden of proof for the facts it alleges (Case Law, supra, III.G.5.1.1). In the present case, the Board considers that since the appellant/opponent raised objections based on the disclosure of samples 1, 3 and 5 of E1, the burden of proof primarily resides on them to show that said samples of E1 effectively belong to the state of the art for the patent in suit.

b) Also, according to established case law, the need for an enabling disclosure of a prior art document is in conformity with the principle expressed in Article 83 EPC, i.e. the requirements of sufficiency of disclosure are identical for a prior art document and a patent (see Case Law, supra, I.C.4.11, in relation to T 206/83 - OJ EPO 1987, 5 - and T 1437/07).

In that respect, as outlined in section 2.3 above, it is concluded in the present case that the skilled person would not be in a position to prepare samples 1, 3 and/or 5 of E1 on the basis of the information provided in E1, even when taking into account common general knowledge. As already indicated in section 2.3.3.d above, the Board is satisfied that there are in the present case serious doubts supported by verifiable facts that E1 constitutes an enabling disclosure for samples 1, 3 and 5 thereof. Therefore, the Board considers that, in the circumstances of the present case, the burden of proof for establishing enablement of samples 1, 3 and 5 of E1 is on the appellant.

2.3.5 The appellant put forward that the respondent's objection that E1 was not enabling should be rejected because the respondent argued the contrary during the opposition proceedings, whereby reference was made to page 2, last paragraph of the minutes dated 19 November 2014 and pages 5-8 of the patent proprietor's letter of 30 March 2015 (appellant's letter of 2 March 2021: page 10, second paragraph).

However, the passage of the minutes relied upon by the appellant are related to arguments put forward by the respondent to demonstrate that the patent in suit was sufficiently disclosed, whereby the reference to E1 was made to show that certain parameters were usual in the art ("The shape with a certain breadth and length was also no unusual parameter as could be seen from E1").

In addition, the Board agrees with the respondent's view that the statements made in their letter of 30 March 2015 which were relied upon by the appellant are related to their argument according to which the skilled person could obtain from E1 information on how to influence e.g. the crystallinity of a ultrahigh molecular weight ethylene polymer, which was not equivalent to a teaching that enabled a skilled reader to actually reproduce the samples of E1, as the nature of the catalyst and the synthesis conditions were not disclosed in E1 (respondent's letter of 6 July 2021: page 9, fourth paragraph). Therefore, said statements of the respondent cannot be equated with acknowledging that the teaching of E1 enabled the skilled person to reproduce the materials disclosed therein, in particular samples 1, 3 and 5.

Also, the Board is satisfied that the same conclusion is equally valid regarding the reference made by the appellant to the respondent's statements in section III and IV on page 7 of their submission of 30 March 2015 (appellant's letter of 20 March 2023: page 5, third paragraph).

For these reasons, the appellant's arguments did not convince.

2.4 In view of the above, E1 does not constitute an enabling disclosure of the ethylene polymer particles prepared therein as samples 1, 3 and/or 5. In view of this, said samples were not available to the skilled person at the priority/filing date of the patent in suit and do not belong to the state of the art.

2.5 Therefore, the appellant's objections of lack of novelty and of lack of inventive step in view of E1, for which it remained undisputed (in particular at the oral proceedings before the Board) that they were all based on samples 1, 3 and/or 5 thereof, are rejected.