T 1627/17 14-01-2020

Main request

1. Sufficiency of disclosure

1.1 Lack of sufficiency of disclosure of independent claims 1 and 8 was addressed in the decision of the opposition division with regards to the ethylene content and the xylene solubles content, both characterizing the metallocene catalysed isotactic propylene-ethylene random copolymer resin, and the haze level, defining the injection molded article comprising that copolymer.

1.2 In order to meet the requirements of sufficiency of disclosure, an invention has to be disclosed in a manner sufficiently clear and complete for it to be carried out by the skilled person without undue burden on the basis of the information provided in the patent specification and, possibly, common general knowledge.

1.3 This means in particular in the present case that the skilled person must be able to prepare an injection molded article according to independent claims 1 and 8, that article being defined in that it comprises a metallocene catalysed isotactic propylene-ethylene random copolymer resin with an ethylene content, xylene solubles content and melt flow rate within specific numerical ranges and in that it exhibits a haze as defined in claims 1 and 8.

1.4 In the contested decision the opposition division held that the determination of the ethylene content and the xylene solubles content by way of measurements involved an undue burden since

- the patent in suit did not disclose which methods, measuring conditions and calculation methods had been used and

- it was established that several methods, measuring conditions and calculation methods were available in the art and that depending on the selection of these, values of ethylene content and xylene solubles content were obtained that did not consistently fall within the ambit of claims 1 or 8 (points 3.1 and 3.2 of the decision under appeal).

1.5 Both the contested decision and the arguments submitted by the respondent in appeal with respect to the determination of the ethylene content and the xylene solubles content of the metallocene catalysed isotactic propylene-ethylene random copolymer resin defined in claims 1 and 8 of the main request relate to the issue of whether or not these two parameters are ambiguously defined because of an alleged lack of information regarding their methods of determination, i.e. if the skilled person is in a position to determine whether or not he is working within the scope of the claims. While the appellant did not dispute the fact that the patent in suit does not indicate a method for the measurement of the ethylene content and the content of xylene solubles, which are characteristics of the metallocene catalysed isotactic propylene ethylene random copolymer resins used to prepare the injection molded article of claims 1 and 8, they argued that that issue was not a matter of sufficiency of disclosure but a matter of clarity (statement of grounds of appeal point 4, page 7).

1.6 The question whether or not that issue effectively amounts to a lack of sufficiency or if it is an issue of clarity was the object of many decisions as indicated in the Case Law of the Boards of Appeal, 9th Edition, July 2019, II.C.5.5, 6.6.4, 6.6.8, 8.2. However, an ambiguity of a parameter in the claims is not enough in itself to deny sufficiency of disclosure and the question whether said ambiguity leads to insufficiency of disclosure is to be decided on a case-by-case basis (see e.g. reference to decisions T 2403/11 and T 608/07 on pages 362, 389 and 390 in the Case Law, supra). Rather, with respect to sufficiency of disclosure, the relevant question is whether the patent in suit provides sufficient information which enables the skilled person, when taking into account common general knowledge, to reproduce the invention (see e.g. reference to decision T 466/05 on page 388 in the Case Law, supra).

1.7 In the present case, the question to be answered for sufficiency is not whether one can establish with a high degree of accuracy all the parameters of the method of determination of the ethylene content or of the xylene solubles content of a metallocene catalysed isotactic propylene-ethylene random copolymer resin, but rather if the skilled person is able to prepare an injection molded article as claimed.

1.8 In that regard, the patent in suit provides information concerning the preparation of the metallocene catalysed isotactic propylene-ethylene random copolymer resin such as the choice of catalyst (paragraphs 9-44), the polymerization process (paragraph 46) and the amount of ethylene monomer involved in the polymerization process (paragraph 47) as well as a description of the injection moulding process leading to the claimed articles (paragraph 53 and the examples, in particular samples 1 and 4). In the absence of any evidence to the contrary, that information is deemed sufficient to allow a skilled person to prepare injection molded articles based on metallocene catalysed isotactic propylene-ethylene random copolymer resin.

1.9 As to the lack of disclosure of the precise conditions under which the polymerization process of the examples was performed, such as the polymerization temperature, the polymerization pressure, the feed rates of the monomers the reactant proportions, the residence time of the monomers in the reactor(s) and the amount of catalyst used (point 3.1.3.1 of the contested decision), it was not shown that the skilled person would not have been able to reduce them into practice on the basis of the common general knowledge available to him.

1.10 Under these circumstances, the Board finds that the skilled person would have been able to prepare an injection molded article as claimed on the basis of the information provided in the patent in suit.

1.11 With regard to the ethylene content and xylene solubles content, while it has been established on the basis of D7 and D14 for the ethylene content and D16 and D17 for the xylene solubles content that the definition of these parameters in claims 1 and 8 was ambiguous due to a lacking definition of the methods, measuring conditions and calculation methods used to determine them, it has not been shown how that lack of accuracy would prevent the skilled person from obtaining the claimed injection molded articles.

1.12 On the contrary, the measurements of the ethylene content reported in Table 2 on page 4 of D7 appear to show that the measurements of low level of ethylene contents according to claim 1 or claim 8 were in principle possible using both NMR and IR methods known to a skilled person since ethylene contents of as low as 2.0% (method 3) and as high as 5.4% (method 1) were obtained. D7 thus shows that several methods were available in the art to the skilled person that would have allowed a measurement of an ethylene content as defined in both claims 1 and 8.

1.13 With regard to the xylene solubles content, D16 and D17 disclose different standards available in the art for the determination of that parameter but these documents are not relevant to the question of sufficiency of disclosure since they do not establish that a skilled person, considering the teaching present in the patent in suit and with help of the common knowledge concerning the preparation of propylene-ethylene based copolymers, would not be able to prepare the claimed injection molded articles.

1.14 It is concluded in view of these considerations that it was not shown that the alleged ambiguity of the definitions of the ethylene content and the xylene solubles content is so severe that it would prevent the skilled person from preparing an injection molded article according to operative claims 1 and 8, i.e. that it amounted to a lack of sufficiency of disclosure. Rather, that issue could at most be related to a matter of clarity pursuant to Article 84 EPC, which however cannot be addressed at the present stage of the proceedings since the parameters in question were already present in the granted claims (see G 3/14, OJ EPO 2015, A102: catchword).

1.15 An additional line of argumentation submitted by the respondent for the first time on appeal was based on an alleged lack of guidance in the patent in suit regarding the implementation of the narrow ranges defining the ethylene content and the xylene solubles content of the metallocene catalysed isotactic propylene-ethylene random copolymer resin comprised in the injection molded article according to claim 1 of the main request (point 2.4 of the reply to the statement of grounds of appeal and point 1.1 of the letter of 13 December 2019).

1.16 The respondent in particular argued that it was not credible that a metallocene catalysed isotactic propylene-ethylene random copolymer resin according to operative claim 1 could be obtained under the conditions mentioned in the patent in suit and that the skilled person would not know how to prepare such a copolymer over the whole scope of that claim, in particular a copolymer having an ethylene content of 2% or more while simultaneously having a xylene solubles content of less than 1.5 %.

1.17 In that respect, an objection of insufficient disclosure presupposes that there are serious doubts, substantiated by verifiable facts and the burden of proof is in that situation primarily on the opponent, i.e. the respondent (Case Law, supra, II.C.9).

1.18 The objection of the respondent is based on the values of ethylene content and xylene solubles content of samples reported in Tables 1 and 2 (Examples 1 and 2) of the patent in suit. If it is correct that the samples in Table 1 do not show a copolymer having an ethylene content of more than 2% while simultaneously having a xylene solubles content of less than 1.5%, that however does not imply that such copolymers were not accessible to the skilled person on the basis of the information contained in the patent in suit, if needed complemented by common general knowledge.

1.19 Sample 8 of example 2 (Table 2) for instance describes a copolymer having an ethylene content of 2% and a xylene solubles content of 0.5-1%, i.e. of less than 1.5%. While it was acknowledged by the respondent that Sample 8 and even Sample 7 in Table 2 might have assisted the skilled person in how to implement a random propylene copolymer having an ethylene content of 2% or higher and a xylene solubles content of less than 1.5% (page 3 of the reply dated 13 December 2019), the respondent argued that since the catalyst used in the preparation of these samples was not disclosed in the patent in suit, the skilled person was not in the position to reproduce their preparations. That argument of the respondent however was not substantiated by verifiable facts showing that the skilled person would not be in the position to select an appropriate catalyst on the basis of the information available to him in the patent in suit or in the common general knowledge. That argument of the respondent therefore fails to convince.

1.20 In the present case, although the description of the patent in suit is broad and allows for a large variety of modifications (e.g. regarding the choice of catalyst and the other polymerization conditions during the preparation of the metallocene catalysed isotactic propylene-ethylene random copolymer resin), there is no evidence on file that working according to the teaching of the patent in suit does not lead to the preparation of metallocene catalysed isotactic propylene-ethylene random copolymer resins as defined in operative claims 1 and 8. Therefore, the respondent's objection is not supported by verifiable facts which would raise serious doubts as to the preparation of metallocene catalysed isotactic propylene-ethylene random copolymer resins as defined in operative claims 1 and 8 to the extent that the burden of proof as to sufficiency of disclosure would lie with the appellant.

1.21 The Board concludes that the respondent's arguments do not allow the conclusion that the skilled person would not be in a position to prepare with a reasonable expectation of success injection molded articles according to operative claims 1 and 8 on the basis of the information of the patent in suit, in particular in examples 1 and 2 thereof, if needed, complemented by common general knowledge. In that respect, it is further credible that injection molded articles may be obtained from the teaching of the patent specification and/or on the basis of the skilled person's common general knowledge.

1.22 With regard to the haze level, the opposition division held that in the absence of any evidence that an injection molded article according to claims 1 or 8 could be prepared from a composition that did not comprise a clarifying agent the patent in suit was not sufficiently disclosed.

1.23 It is correct that neither claim 1 nor claim 8 contains any limitation regarding the presence or absence of clarifying agents or even clarity-enhancing agents as defined in paragraph 54 of the patent in suit. That however is not relevant to the question of sufficiency of disclosure of claims 1 and 8 of the main request, since none the relevant parts of the description of the patent in suit addressing the clarity or the haze level of the claimed injection molded article implies that clarifying agents or clarity-enhancing agents are necessary to obtain the claimed haze levels (paragraphs 54 to 59).

1.24 It is in particular apparent from the sentence "One approach to obtaining such improvement in clarity has involved the use of so-called clarity-enhancing agents." in paragraph 3 of the introductory part of the patent in suit that the presence of a clarity-enhancing agent in propylene-based polymers is not necessary in order to impart clarity. That is in line with the passage on paragraph 4 cited in the contested decision, also repeated in paragraph 54, which mentions that improved clarity could be obtained with or without the use of clarifying agents (paragraph 4) or clarity-enhancing agents (paragraph 54). Indeed, the patent in suit teaches that the clarity performance also depends on other factors such as the type of catalyst used to prepare the isotactic propylene-ethylene random copolymer resin (paragraph 52), its ethylene content, its xylene solubles content, its melt flow rate and the thickness of the produced injection molded article (paragraph 58).

1.25 In that regard, it is irrelevant whether a clarifying agent or clarity-enhancing agent is used or not during the preparation of the claimed injection molded articles as long as the article has the required level of haze as defined in the claims. With respect to the examples of the patent in suit, it is undisputed that a clarifying agent (Millad TM 3988) was used in all instances. Since all examples contain a clarifying agent, no conclusion can be reached on which results would be obtained if no clarifying agent were used and therefore on whether the presence of a clarifying agent was necessary to obtain the claimed level of haze. In that respect also, no other verifiable facts were provided by the respondent that would support the existence of serious doubts as to whether the claimed articles having the required level of haze could only be obtained in the presence of clarifying agents. Under these circumstances, it cannot be concluded that claims 1 and 8 lack sufficiency of disclosure with respect to the haze level defined in these claims.

1.26 The Board concludes from the above that the patent is sufficiently disclosed.

2. Remittal

2.1 Sufficiency of disclosure was the only ground of opposition discussed at the oral proceedings before the opposition division and it was the only ground of opposition upon which a decision was taken. All the parties present to these appeal proceedings requested the remittal of the case to the opposition division for consideration of the further grounds of opposition that had been raised by the opponent in their notice of opposition (lack of novelty and lack of intentive step - Article 100(a) EPC).

2.2 Although the EPC does not guarantee the parties an absolute right to have all the issues in the case considered by two instances, it is well recognised that any party may be given the opportunity of two readings of the important elements of a case. The essential function of an appeal is to consider whether the decision issued by the first-instance department is correct. Hence, a case is normally to be referred back if essential questions regarding the patentability of the claimed subject-matter have not yet been examined and decided by the department of first instance (Article 111(1) EPC).

2.3 Moreover, the facts under point 2.1 including the common request of all parties are for the Board special reasons in the sense of Article 11 RPBA 2020 for which a remittal of the case to the opposition division for further prosecution is appropriate.