T 0790/03 20-07-2006

1. The appeal is admissible.

2. Procedural matters

2.1 Article 107 EPC states that "Any party to proceedings adversely affected by a decision may appeal. Any other parties to the proceedings shall be parties to the appeal proceedings as of right.". On the basis of this wording and in agreement with established jurisprudence (cf. T 73/88, OJ EPO 1992, 557, No. 1.2 of the reasons; T 270/94 of 22 January 1998, No. 2.1 of the reasons; and T 863/96 of 4 February 1999, No. 2 of the reasons, neither of the latter decisions published in OJ EPO), the Board takes the view that neither the opposition nor the appeal proceedings resulting therefrom can be split into different procedures, each dealing separately with the grounds for opposition and the facts, evidence and arguments presented in the Notice of Opposition of the respective opponent.

Decision T 448/89, referred to by the Respondent (section VII (4), above), did not concern the above issue, but the question of admissibility of an opposition based on objections of lack of novelty and of lack of inventive step, which had been formulated in the Notice of Opposition only in very general terms on the basis of a passage in a granted EP-patent published only after the effective date of the patent in suit. This reference in its generality was not, under the specific circumstances in that case, found to comply with the requirements of Rule 55(c) EPC, despite the fact that it had been possible to identify the pre-published patent application corresponding to the cited EP-patent.

Consequently, the arguments of the Appellant which deal with an objection duly submitted by Opponent I/the other Party within the time limit of Article 99(1) EPC cannot simply be disregarded, solely because they are based on the documents cited by the other Party (ie in the present case: D5 to D10).

2.2 In the Statement of Grounds of Appeal, the Appellant cited two further documents for the first time, ie D11 and D12. In its reply (section VII (3), above), the Respondent requested that these documents be excluded from the proceedings.

2.2.1 The question of the admission of late-filed evidence and late-filed documents with due consideration of Article 114(1) and (2) EPC was considered in decision T 1002/92 (OJ EPO 1995, 605, Nos. 3 to 3.4 of the reasons). Reference can thus be made to the summary of that aspect of T 1002/92 as given in Headnote II:

"In proceedings before the Boards of Appeal, new facts, evidence and related arguments, which go beyond the 'indication of facts, evidence and arguments' presented in the notice of opposition pursuant to Rule 55(c) EPC in support of the grounds of opposition on which the opposition is based, should only very exceptionally be admitted into the proceedings in the appropriate exercise of the Board's discretion, if such new material is prima facie highly relevant in the sense that it can reasonably be expected to change the eventual result and is thus highly likely to prejudice maintenance of the European patent; and having regard also to other relevant factors in the case, in particular whether the patentee objects to the admissibility of the new material and the reasons for any such objection, and the degree of procedural complication that its admission is likely to cause."

2.2.2 Therefore, the request of the Respondent not to take documents D11 and D12 into consideration can be examined within those conditions as established in T 1002/92 (above), (i) with respect to the question of their relevance and (ii) , if found relevant, with regard to the state of the proceedings at the date of their filing. Since aspect (i), above, is closely related to the issue of inventive step, it will be dealt with in that context herein below.

3. Wording of the specification

As addressed in sections III, VII (2), VIII (3) and X (above), respectively, an amended set of claims and an amended page 2 of the description formed the basis of the decision under appeal and this version of the patent in suit is further pursued by the Respondent in these appeal proceedings.

The amendments in Claim 1 consist in the identification of the method of measuring the dart impact according to ASTM D-1709 (ie "Method A") and the limitation of the melt flow ratio (MFR) range of the LLDPE used to "15 to 20" on the basis of page 4, line 4 and page 3, line 6 of the application as published, respectively. Paragraphs [0004] and [0014] on page 2 of the description were amended accordingly.

Hence, it is evident that Article 123(2) EPC is complied with. Since the two amendments also clearly limit the scope of Claim 1 as granted further, the requirements of Article 123(3) EPC are also met.

4. Article 100(b) EPC

4.1 With regard to a first aspect of this objection, the Appellant has relied only on the arguments provided in the Notice of Opposition of Opponent I (sections II and VI (1), above). Those arguments were, however, disputed by the Patent Proprietor (sections III and VII (5), above) and were also refuted in the decision under appeal (cf. section V (1), above), because they had been based on experiments neither being true repetitions of the examples of the patent in suit as alleged nor being convincing. Moreover, no additional arguments have been brought forward by the Appellant in this respect, nor have the findings in the decision under appeal or the comments of the Respondent in its reply to the Statement of Grounds of Appeal (sections V (1) and VII (5), above) been challenged by the Appellant or the other Party within more than two years between the submission of the Respondent's reply and the summons, let alone thereafter.

Therefore, the Board has no reason to deviate from the findings in the decision under appeal with regard to this aspect of the objection.

4.2 With regard to a second aspect of this objection, the Appellant maintained that the skilled person was not in a position to reproduce the claimed subject-matter over the various ranges recited without a significant experimental burden, because he would not know how to achieve values of the various parameters in the claim other than those in the single example of the patent in suit (cf. sections IV and VI (1), above).

4.2.1 This aspect of the objection had been refuted in the decision under appeal (section V (1), above), in particular due to lack of any evidence for these assertions.

4.2.2 The absence of any evidence from the side of the Appellant was also addressed by the Respondent, who additionally pointed out that the onus of proof for its allegations had been on the Appellant and that the Appellant had not discharged this burden (section VII (5), above).

4.2.3 Although it had, thus, clearly been derivable from the decision under appeal that a "mere statement" had not sufficed for a success of this second aspect of the objection under Article 100(b) EPC (decision under appeal: No. 3.1 of the reasons; section V (1), above) and the Respondent had also addressed this weakness in the argumentation of the Appellant, no evidence has been provided to demonstrate that "the invention cannot be performed over the entirety of the breadth claimed" (section VII (5), above) ever since. In the absence of such evidence, the Board cannot, therefore, refute the arguments of the Respondent in this respect.

4.2.4 Moreover, the presentation of this aspect by the Appellant is not convincing, in the Board's view, for a still further reason. Thus, the Appellant argued, on the one hand, that the skilled person could not carry out the invention, ie could not prepare something within the scope of the claims, but, on the other hand, expressed, at the same time, the opinion with regard to the prior art cited, that it would have been obvious and within normal skills of a person skilled in this art to arrive at something within the scope of these claims (Statement of Grounds of Appeal: page 6, third last paragraph; and Notice of Opposition: Annex 1, the paragraph bridging pages 2 and 3).

This inconsistency within the arguments of the Appellant becomes evident, in particular, when comparing its own statements dealing with the haze feature (mentioned just to give an example):

(a) "... there is no disclosure in the patent in suit as to how a skilled person should obtain a film having a haze ratio outside the only value quoted of 5-7%" (Statement of Grounds of Appeal, page 3, paragraph 2; section VI (1), above).

(b) "The haze values of D12 range from approximately 3.5 to 4.2 ..." (Statement of Grounds of Appeal: page 4, penultimate paragraph; section VI (3), above, paragraphs 3 and 1, respectively).

4.3 Therefore and in summary, the Board cannot see any reason to deviate from the findings in the decision under appeal concerning the objection under Article 100(b) EPC. Consequently, this objection is rejected.

5. Novelty

In the appeal proceedings, the initial novelty objection, which had been rejected by the Opposition Division (section V (2), above), has no longer been pursued by the Appellant. Under these circumstances, the Board has no reason to deviate in this respect from the decision under appeal.

6. Problem and solution

6.1 The patent in suit concerns a film comprising a LLDPE comprising ethylene and C3-10-alpha-olefin.

The film as defined in Claim 1 is required simultaneously to meet certain requirements with regard to its optical, chemical and mechanical properties, namely to have haze, dart impact and hexane extractables within defined limits. Moreover, further prerequisites in the claim concern limitations of a number of properties of the LLDPE used to form the film, ie its density, its melt flow ratio, its molecular weight distribution and its melting point (Claim 1, section III, above).

6.2 The common general knowledge, that these properties of the polymer depend on its chemical composition, the catalyst system and the polymerisation conditions used in its preparation, is not only confirmed by the specification itself, which contains three chapters with the headings of "The Copolymer Products" (including a reference to the monomers; [0020]), "The Catalyst" (eg those based on metallocenes and aluminoxane cocatalysts) and "The Process Conditions" (eg low pressures in the range of 1 to 2.4 MPa [0036]), but also eg by document D10, initially cited in the opposition and, at the hearing before the Opposition Division, identified by the Appellant/Opponent II as the closest piece of prior art (section IV, above). Last but not least it was also confirmed by the Appellant itself (cf. section VI (3), paragraph 1).

6.2.1 Document D10 is based on a presentation given on a congress and addressing some then already achieved and further expected aspects of a specific (EXXPOLTM) technology on the basis of a particular type of catalyst system (referred to as "single site catalyst", "SSC"). This technology was said to allow a "tailor-made structuring of the polymer", the control of MWD and the making of polymers with narrow CD, and, thus, at the time of its publication, nurtured expectations for the future ("One approach we might see in tailoring polymers to meet customer needs is ..."). The needs (required properties) are, of course, related to the intended use of the polymers. Thus, the document further mentions a number of "properties such low heat-sealing temperatures, low haze, high clarity, impact resistance, elasticity and potentially - improved recyclability" (page VII-1.5, right column; and bottom of the left column on page VII-1.7) and a number of uses, such as "packaging film, electrical, automotive, medical devices, and textiles" (page VII-1.8, left column). When considering these expositions, it must, however, be taken into account that this document was not meant by its author "to be a technical presentation" (page VII-1.8, right column, paragraph 2).

6.2.2 Nevertheless, it referred to some technical particulars, namely (i) to different monomers (cf. the references to different polymers in the abscissas in the first and last bar charts, respectively, on pages VII-1.8 and VII-1.9), (ii) to single site catalysts (with particular reference to their ionic so-to-say sub-species composed of metallocene cations and anionic coactivator systems; page VII-1.6, right column) and (iii) to polymerisation conditions, namely to high pressure in a high pressure polymerisation line (page VII-1.6, left column, paragraph 2). Moreover, four figures, ie a diagram and altogether three bar charts, were included to give an idea in which way some properties of different polymers could be influenced by choosing a catalyst ("Exact single site polymers versus LLDPE and VLDPE"; page VII-1.8, right column, last paragraph). Thus, reference was made (a) to melting points of some "Ziegler Catalyzed Polymers" and of some "EXACT" polymers, (b) to hexane extractables of some "C4, C6 and C8 LLDPE" and some " C4, C6 and C8 VLDPE" polymers prepared by means of either a Ziegler-Natta catalyst or a SSC, as well as (c) to the dart drop impact resistance of some cast films and (d) to the total haze of some blown films, both types of films prepared from the different types of polymers mentioned. However, no further particulars or details were given which would allow to establish that a polymer of a given type in one figure was identical to a polymer of the same type referred to in another figure.

In other words, it is not unambiguously clear from the figures that eg the Exact Single-Site C4 VLDPE in the dart drop bar chart was identical to the C4 VLDPE Exact Single-Site Polymer in the Hexane Extractables bar chart or to one of the Exact polymers mentioned in the Total Haze chart of D10, which cannot be further identified in the provided copy (page VII-1.9).

Furthermore, in the discussion between the parties about the various properties of the polymers in D10 and their relevance to the claimed subject-matter, one aspect mentioned above was completely left aside: point (iii), the polymerisation conditions and their influence on the products (cf. eg D5, column 1, line 19 et seq., column 3, line 53 to column 4, line 34). The importance of this aspect can be illustrated eg by the well-known differences in clarity (haze) of two typical commodity product types in this field of the art, namely a high pressure polyethylene (LDPE) as opposed to a low pressure polyethylene (HDPE). D10 clearly refers to a high pressure polymerisation line (see the first paragraph of this section, above). By contrast, the description of the patent in suit refers only to pressures of 1 to 2.4 MPa (150 to 350 psi) [0036], clearly different from commonly known high pressure processes (cf. D5: column 1, lines 19 to 22, referring to "pressures as high as 50,000 psi").

6.2.3 In summary, this means that D10 does not allow to conclude that, in one of its films, specific values within the limits of those parameters as defined in Claim 1 had simultaneously been achieved or even could simultaneously be achieved.

6.3 It is exactly this conclusion, to which the Respondent also came with regard to documents D11 and D12, cited only in the Statement of Grounds of Appeal (cf. sections 2.2 to 2.2.2, above), after having dealt extensively with the details of these documents, in particular with the individual parameters of individual polymers in D12, in its reply to the Statement of Grounds of Appeal (section VII (1) to (3), above).

6.3.1 Although the Appellant had, in the Statement of Grounds of Appeal, mainly relied on this latter document (sections VI to VI (3), above), against the consideration of which in these appeal proceedings had been pleaded by the Respondent, further arguments were provided neither by the Appellant nor the other Party to dispute, let alone to refute the detailed arguments of the Respondent after the filing of the reply of the Respondent in February 2004, not even after having received the summons to oral proceedings (sections VIII and VIII (2), above).

6.3.2 Moreover, the comparison of the detailed arguments of the Respondent and the contents of the new documents shows that, whilst referring to properties of the products prepared by a SSC catalyst system in more detail than D10 (D12 even mentioning the term EXXPOLTM), both documents concern, like D10, polymers having a particularly narrow MWD. More particularly, the MWD of a number of polymers of different monomer compositions was specified therein in terms of a Mw/Mn-value of 2.0 (D11: first page, left column, line 14 from below; D12: Introduction on page 46, second paragraph).

Furthermore, both documents D11 and D12 are completely silent about the polymerisation conditions (see section 6.2.2, above) and, like D10, they also fail to demonstrate that the properties of a film as defined in Claim 1 could and would be obtained simultaneously with a given polymer composition.

In view of these facts and of the arguments of the Respondent which remained undisputed, the Board cannot refute the argument of the Respondent that the two documents D11 and D12 are not more relevant than the prior art, which had been considered in the opposition proceedings (see section 2.2.1, above), and that the Appellant's arguments based on the citation of the new documents were based on hindsight (section VII (1), above).

In view of these findings, there is no need for the Board further to consider these two late-filed documents in more detail for the assessment of inventive step, and they are therefore excluded from consideration (Article 114(2) EPC).

6.4 Consequently, the Board has no reason to deviate from the Appellant's view in the opposition hearing that D10 was the closest piece of prior art (sections IV and 6.2, above).

6.5 According to paragraphs [0016], [0017] and [0018], the technical problem may be seen in the provision of a film showing simultaneously a number of distinct optical properties and mechanical properties, which film can easily be prepared from LLDPE products having various unique properties [0010].

6.6 This problem is solved by the subject-matter of Claim 1.

Moreover, as indicated in Table II of the patent in suit, the particular combination of properties was, in fact, obtained. These values per se were not in dispute.

Therefore, the Board is satisfied that the above relevant technical problem was credibly solved.

7. Inventive step

It remains to be decided whether the claimed solution of this problem derives in an obvious way from the cited documents.

7.1 As already shown in sections 6.2 to 6.2.3, above, D10 itself does not provide all the details of the solution found for the above technical problem. In particular and as pointed out in the decision under appeal (No. 6.10), it is silent as to the MFR and a specific range of the MWD, viz. a MFR of 15 to 20 and a Mw/Mn of 2.5 to 3.0. Moreover, there is no teaching in the document of how to obtain films fulfilling all the requirements of Claim 1 simultaneously.

Although in part correct, the reasoning given for this fact by the Appellant on page 6, paragraph 3, of the Statement of Grounds of Appeal, that the MFR was associated with the bulk resin and not the film itself and that, therefore, a MFR value for a LLDPE film was a meaningless quantity and that, therefore, their was no need for its mentioning in D10, is not convincing. Thus, firstly, the relevant requirement in Claim 1 is clearly related to the LLDPE as such to be used ("... said film comprising a LLDPE ..., which has ...; MFR ...", and, secondly, it has not been demonstrated by the Appellant (Opponent II) or the other Party that this property of the starting polymer would not have any effect on the properties of the film prepared therefrom. The onus of proof was clearly on the opponents who raised the objection. However, this burden was not discharged by either of them.

Nor does D10 provide any incentive to use a polymer having a MWD of 2.5 to 3.0 for obtaining a film having the required properties.

Consequently, D10 itself does not render the subject-matter as defined in Claim 1 of the patent in suit obvious.

7.2 In a number of the further documents cited by the opponents during the opposition proceedings and relied on by them in their objections of lack of inventive step, no mention was made at all of films (section V (2), above). Consequently, none of them can contribute to the solution of the relevant technical problem.

7.3 Document D5, which had been acknowledged in the patent in suit [0003], relates to films made from low density ethylene hydrocarbon copolymers made from at least 90 mol % of ethylene and at most 10 mol % of at least one C3-8-alpha-olefin by means of a transition metal based catalyst and having a melt index of about >=0.1 to about <=5.0 (D5: Claim 1). The broadest limitation of the MWD of these copolymers is found in its Claim 4 (about >=2.7 to <=3.6), the range of which overlaps with the range defined in Claim 1 under consideration. The same is valid for the density (>=0.912 to <=0.940; Claim 3). However, the broadest range of the MFR of these copolymers as disclosed in D5 can be found in its Claim 5 ranging from about >=22 to <=36, preferably >=25 to <=32 (cf. also D5: column 7, lines 60 to 63).

In the decision under appeal (No. 6.5 of the reasons), D5 was referred to as neither teaching films having the particular combination of parameters of the pending Claim 1, nor referring to the specific LLDPE of the pending Claim 1. For instance, it did not mention a polymer having a MFR-value of 15 to 20.

This finding in the decision under appeal was not challenged at all by the Appellant, nor has the Board any reason for raising any doubts in this respect.

Besides, the Board found no suggestion or incentive in D5 to modify the disclosure of D10 so as to solve the above relevant technical problem. Therefore, it has arrived at the same conclusion as the Opposition Division in the decision under appeal (No. 8.2 of the reasons) in this respect.

7.4 According to the decision under appeal (No. 6.6 of the reasons), the same findings are also valid for D6, which have not been disputed by the Appellant either.

Hence the Board has come to the same conclusion as in section 7.3, above.

7.5 In summary, the Appellant has not provided any convincing argument for an incentive to modify the disclosure of D10 in order to solve the relevant technical problem (section 6.5, above) and thereby to arrive at something within the scope of present Claim 1.

Rather the Board has come to the conclusion that the arguments provided by the Appellant were based on an analysis of the different features of different polymers, as confirmed by pages 7 (starting at paragraph 3) to 9 of the Statement of Grounds of Appeal. As argued by the Respondent (sections VII and (1), above), such an analysis can only be considered as being based on an inappropriate ex-post facto analysis.

8. It follows that, besides the requirements of novelty and sufficiency of disclosure, the subject-matter of present Claim 1 according to the request of the Respondent also fulfils the requirement of Article 56 EPC; hence, it involves an inventive step.

9. By the same token this finding is also valid for the remaining dependent claims which include the same features as discussed above with respect to Claim 1.

10. Since the Appellant withdrew its Auxiliary Request for oral proceedings and the Main Request of the Respondent is successful, there is no need to hold oral proceedings.