T 0148/05 11-10-2006

Reasons for the Decision

1. The appeal is admissible.

2. Procedural matters

As can be seen from Section VIII above, the Board at the oral proceedings has been confronted at the beginning of the oral proceedings of 11 October 2006 with the following procedural issues:

(i) the question of the admission of documents D36 to D44 into the proceedings and

(ii) the question of remittal to the first instance in view of the admission of late filed documents into the proceedings.

2.1 Concerning point (i):

(a) As stated in decision T 117/86 (OJ EPO 1989, 401) facts and evidence in support of an opposition which are presented after the nine-month period has expired are out of time and late, and may or may not be admitted into the proceedings as a matter of discretion under Article 114(2) EPC.

(b) Since the grant of the European Patent EP 0 990 006 was announced on the 30 January 2002, the nine-month period ended on the 30 October 2002.

(c) As indicated above in paragraph V, documents D36 to D43 were submitted by the Appellant with the Statement of Grounds of Appeal, i.e. on 26 April 2005, and document D44 was submitted with letter dated 19 September 2006.

(d) It thus follows that documents D36 to D44 must be regarded as late filed.

(e) Although it is the established case law of the boards of appeal, that the main criterion for deciding on the admissibility of a late filed document is its relevance, i.e. its evidential weight in relation to other documents already in the case, further considerations which can play a decisive role in the question of admittance of late filed evidence are the degree of lateness and whether the late filing can be seen as representing an abuse of the proceedings (cf. T 1019/92 of 9 June 1994; not published in OJ EPO, Reasons, point 2.2)

(f) In the present case, the issue of admissibility of documents D36 to D43 into the proceedings, hence, boils down to the following questions:

(f.1) as to whether the late filing of documents D36 to D44 by the Appellant is to be seen as representing an abuse of proceedings,

and, if question (i) is negatively answered,

(f.2) as to whether the relevance of documents D36 to D44 is prima facie such to justify their introduction into the proceedings.

(g) In the present case, the Opposition Division has, in substance, considered in its decision that document D3 could not challenge the novelty of the subject-matter of granted Claim 1, and that documents D13 and D15 could not be considered as novelty destroying for the subject-matter of Claim 5. According to the decision, D3, on the one hand referred to the use of MDI in its paragraph "Systembeschreibung", which term normally meant, in the Opposition Division's view, a mixture of 2-ring oligomers without 3-ring oligomers, and, on the other hand, it did not disclose that isocyanate B223 used in the test formulation was mandatorily used together with the blowing agent R 134a (Reasons point 5.2). Concerning documents D13 and D15, it was held that there was no evidence about the composition of Desmodur® 44V70 at the priority date or filing date of D13 and D15, since document D20 only disclosed analysis results of that product between 1st and 31st January 1995. Concerning inventive step, it was in particular considered in the decision under appeal that there was no indication in the cited documents on the influence of the dimer amount and dimer/trimer ratio on the mechanical properties of the rigid polyurethane foam such as dimensional stability and compressive strength.

(h) According to the Appellant the filing of the documents D36 to D44 should hence be seen as a reaction to the decision of the Opposition Division in order to improve its position with respect to the issues of novelty and inventive step.

(i) In that respect, the Board notes that document D36 which is very similar to D3 uses, in contrast to D3, the term "polymeres Diphenylmethandiisocyanat (PMDI)" in its Section "Systembeschreibung", that document D37 discloses a test formulation in which the same blowing agent as mentioned in its Section "Systembeschreibung" is used in combination with Isocyanat B223, and that documents D38 and D39 related to the composition of Desmodur® 44V70 before the priority date of D15. The Board also notes that document D43 appears to make a link between the functionality, the viscosity of the polyisocyanate component and the mechanical properties of the rigid polyurethane foams obtained therefrom, and that documents D40, D41, and D42 seem to establish a difference in functionality and viscosity between the polyisocyanate M20S (D42) and the polyisocyanate M50 or B223 (D40 and D41).

(j) According to the Board, it is justified that a party which has lost in the opposition proceedings tries during the appeal proceedings to fill a presumed missing link in order to improve its position with respect to the issues of novelty and/or inventive step.

(k) Since furthermore documents D36 to D43 have been filed at the earliest possible moment in the appeal proceedings, namely with the Statement of Grounds of Appeal, their filing in the appeal proceedings is, in the Board's opinion, legitimate and does not represent unfair behaviour and cannot therefore be considered as amounting to an abuse of procedure.

(l) This conclusion could not in the Board's view be altered by the arguments of the Respondent, that the Opponent had already been made aware by the communication issued by the Opposition Division on 19 April 2004 in an annex to the summons to oral proceedings scheduled to take place on 27 October 2004, that the test formulation in D3 did not contain a blowing agent, and that document D20 could not provide evidence of the composition of Desmodur® 44V70 used in the documents D13 and D15 for the following reasons:

(i) The Board firstly observes that D38 and D39 are documents originating from a third party (Bayer AG), and it is hence questionable whether they could have been obtained by the Opponent (Appellant) before the final date for filing written submissions before the oral proceedings set out (i.e. 27 August 2004) by the Opposition Division in its communication.

(ii) In any case, there is, in the Board's view, no suggestion, even if documents D36, D37, D40, D41, and D42 originate from the Appellant itself, that there was a deliberate decision of the Appellant for tactical reasons not to cite documents D36 to D43 at that time (cf. T 1019/92; point 2.2 of the Reasons, cited in Catchword II).

(iii) Thus, the Board can only consider that the Appellant did not realize, through inadvertence, at that time the possible consequences of not taking into consideration the statements made by the Opposition Division in its communication annexed to the summons to oral proceedings on the issue of the opposition procedure before the Opposition Division, and that it thus decided not to carry out an additional search at that time.

(iv) It thus follows that the filing of the documents D36 to D43 by the Appellant with its Statements of Grounds of Appeal, is to be seen, in the Board's view, as an attempt to smooth out, as quickly as possible, its previous inadvertence, but in no case as representing an abuse of proceedings.

(m) Document D44 can also be seen as reaction to the decision of the Opposition Division, since it is presented as reflecting the manner according to which a person skilled in the art of making rigid polyurethane foams would interpret the technical leaflets D3 and D36, in particular, in view of the respective Sections "Systembeschreibung" and "Eingangsprüfung" in these documents.

(n) While it is true that document D44 has been filed only three weeks before the Oral Proceedings before the Board, it is, in the Board's view, not unthinkable, that there were some difficulties of obtaining an opinion of an independent expert in the field of rigid polyurethane foams concerning the interpretation of documents D3 and D36, which hence render plausible its belated submission (cf. T 326/87; OJ EPO 1992, 522; Reasons point 5). Consequently, the filing of D44 cannot amount to an abuse of procedure.

(o) It thus follows from the above that question (f1) above must be answered negatively.

(p) Since it is, in the Board's view, prima facie evident (cf. paragraphs (i) and (m) above) that documents D36 to D44 are likely to improve the position of the Appellant with respect to the issues of novelty and/or inventive step, and hence to challenge the reasons for which the Opposition Division decided to reject the objections of lack of novelty and lack of inventive step raised by the Opponent (Appellant), question (f2) is to be answered positively.

(q) Consequently, the Board decides to introduce documents D36 to D44 into the proceedings.

2.2 Concerning point (ii):

(a) As indicated above in Section VIII, the Respondent took the view that the case should be remitted to the first instance since the late filed documents D36 to D44 were introduced into the proceedings. Although no formal request in that respect had been submitted by the Respondent during the written phase of the appeal, the Respondent was of the opinion, on the one hand that such a request derived implicitly from its request to disregard the documents D36 to D43 presented in its letter dated 27 October 2005 and reiterated in its letter dated 21 September 2006, and, on the other hand, that it was established jurisprudence of the boards of appeal to remit the case to the first instance when documents were introduced into the proceedings at a very late stage in order to preserve the right of a party to have its case examined by two instances.

(b) In the Board's view, remittal due to the admission of new documents should rather be an exception i.e. if, without remittal, a party would not have had sufficient opportunity to defend itself against an attack based on the new documents, or if the factual framework has changed to such an extent that the case is no longer comparable with the one decided by the first instance (cf. also decision T 966/95 of 24 March 1999; not published in OJ EPO, Reasons point 2.2).

(c) In that context, it is clear, in the Board's view, that documents D36 to D44 (cf. paragraph 2.1 (i) above) only reinforce the lines of attack already made by the Appellant before the first instance, so that it cannot be considered that the factual framework has changed to such an extent that the case is no longer comparable with the one decided by the first instance.

(d) The Board further observes that documents D36 to D43 have been cited at the very beginning of the appeal procedure, that document D44 is in line with the arguments developed by the Appellant in paragraph III 1.1 of the Statement of Grounds of Appeal, and that the Respondent has not only commented the documents D36 to D43 in its letter dated 28 October 2005 but that it had submitted 4 auxiliary requests with its letter dated 21 September 2006 in order to take into account the objections raised by the Appellant in view of these documents.

(e) Consequently, the Board can only come to the conclusion that the Respondent has had sufficient opportunity to defend itself against the attack based on the new documents, which it did until the oral proceedings without requesting remittal of the case to the first instance.

(f) Since no surprising disadvantage for the Respondent arose from the introduction of documents D36 to D44, there is no reason for the Board to remit the case back to the first instance. Hence, the Board considers it appropriate to make use of its discretionary powers under Article 111(1) EPC and to exercise any power within the competence of the department which was responsible for the decision appealed.

Main request (Claims 1 to 9 as granted)

3. Lack of novelty of the subject-matter of Claim 1 of the main request had been alleged by the Appellant in view of documents D3 and D36. The Appellant has also submitted that documents D37 and D15 were novelty destroying for the subject-matter of Claim 5.

3.1 Document D3 is a technical leaflet referring to the CFC-free polyurethane system Elastopor® VP H 230/008 for the manufacture of rigid polyurethane foams and dated 08/1996 (i.e. August 1996).

3.2 In its Section "Systembeschreibung" D3 discloses that the polyurethane system Elastopor® VP H 230/008 is delivered in form of five components which are:

for the polyol component (A-component)

(i) Elastopor® VP H 230/008/0 (polyol mixture without activator but with flame retardant);

(ii) Aktivator KX 315;

(iii) Zusatzmittel ZM 99; and

(iv) Treibmittel R 134a and

for the Isocyanat component (B-component)

(v) MDI (Diphenylmethanediisocyanat).

According to D3 (page 2, last paragraph) the isocyanate component exhibits, at 20ºC, a density of 1.24g/cm**(3) and a viscosity of 850 mPas.

3.3 In its Section "Eingangsprüfung" D3 discloses a formulation for the reception test of the delivered system. This composition consists of:

100,0 parts by weight of Elastopor® VP H 230/008/0;

2,1 parts by weight of KX 315;

3.5 parts by weight of ZM 99, and

133,0 parts by weight of Isocyanat B223 and defines the foaming characteristics which should be met by this composition (cf. paragraph "Schäumverhalten").

3.4 In this connection, the Board notes that Claim 1 of the main request requires, explicitly,

(i) that the polyisocyanate composition be reacted with an isocyanate reactive composition in the presence of a hydrofluorocarbon blowing agent;

(ii) and that the polyisocyanate composition comprises (a) from 15 to 42 percent by weight of diphenylmethane diisocyanate, (b) three ring oligomers of polyphenylene polymethylene polyisocyanate in an amount such that the ratio of (a) to (b) is equal to from 0.2 to 1.8 and (c) higher homologues of polyphenylene polymethylene polyisocyanate.

3.5 According to the decision T 355/99 of 30 July 2002 (not published in OJ EPO), it is not sufficient for a finding of lack of novelty that the claimed features could have been derived from a prior art document, there must have been a clear and unmistakable teaching of the claimed features (Reasons, point 2.2.4).

3.6 It should hence be checked whether there is in D3 a clear and unmistakable teaching of the combination of features (i) and (ii) mentioned above in paragraph 3.4.

3.7 While it is immediately evident that the use of the polyurethane system Elastopor® VP H 230/008 implies the reaction of the polyol component (A-component) comprising the blowing agent R 134a (i.e. tetrafluoroethane, in other words a hydrofluorocarbon blowing agent) with an isocyanate component (B-component), it is true, as argued by the Respondent, that D3 in the Section "Systembeschreibung" only refers to the use of diphenylmethane diisocyanate (MDI) as B-component without, however, specifying the composition of the isocyanate.

3.8 It is further true, that the formulation for the reception test which specifies the isocyanate component (B223) used, does not comprise the blowing agent R134a and that document D3 fails to explicitly disclose the composition of the isocyanate B223.

3.9 Consequently, the question of lack of novelty of the subject-matter of Claim 1 over D3 boils down to the questions:

(a) as to whether the skilled person would consider that the isocyanate B223 used in the formulation for the reception test is the isocyanate component used in the system Elastopor® VP H 230/008;

and if the question (a) is answered positively, whether (b) the composition of the isocyanate B223 meets the requirements set out in Claim 1 for the isocyanate component.

3.9.1 While document D3 in its Section "Systembeschreibung" explicitly identifies with commercial references, in contrast to the isocyanate component, the four elements of the A-component, this does not imply, in the Board's view, that any MDI could be used in the system Elastopor® VP H 230/008. In the Board's view, the need for a specific identification of the four elements of the A-component should be seen in the fact that these components must be mixed in the A-component before the reaction with the B-component, while the isocyanate component is used as delivered (in red barrel in contrast to the blue barrels used for the polyol components). In any case, it is clear from the description of the system Elastopor® VP H 230/008 that this system is delivered as whole, and that therefore it consists of five interrelated specific components. This view is further supported by the fact that document D3 indicates the characteristics of the MDI component in terms of density and viscosity, which further underlines the specificity of the isocyanate used as B-component in the system Elastopor® VP H 230/008.

3.9.2 Consequently, the Board comes to the intermediate conclusion that the isocyanate component to be used in the system Elastopor® VP H 230/008 is specific to that system.

3.9.3 Since, as indicated above, the system is delivered as a whole to the client, it thus follows that the aim of the reception test ("Eingangsprüfung") must hence be seen in the verification that the delivered system meets the requirements in terms of foaming properties set out in this test. While the necessity to carry out the reception test with the delivered components of the system finds further its justification in view of the legal implications in terms of responsibility of the seller of the system Elastopor® VP H 230/008 towards the buyer of this polyurethane system (cf. also D44, page 2, fourth paragraph), it is however conceivable that, for technical reasons due to the very low boiling point of the blowing agent R134a (-26,5ºC), the formulation for the reception test could not use the blowing agent specified in the system Elastopor® VP H 230/008.

3.9.4 It follows from the above considerations that the formulation used for the reception test must be regarded as consisting of four of the five elements of the delivered system. This has for its consequence that the isocyanate B223 used in this formulation is inevitably the isocyanate used in the system Elastopor® VP H 230/008.

3.9.5 It remains hence to be examined whether the composition of the isocyanate B223 meets the requirements set out in Claim 1 for the isocyanate composition.

3.9.6 In that respect, according to decision T 793/93 of 27 September 1995 (not published in OJ EPO), "concerning the issue of novelty, Article 54(2) EPC defines a state of the art as comprising "everything made available to the public by means of written or oral description, by use or in any other way. The term "available" clearly goes beyond literal or diagrammatical description, and implies a communication, express or implicit, of technical information by other means as well. In the case where a prior art document fails explicitly to disclose something falling within a claim, availability in the sense of Article 54 EPC may still be established if the inevitable outcome of what is literally or explicitly disclosed falls within the ambit of that claim" (Reasons 2.1). As further stated in decision T 793/93 "in deciding what is or is not the inevitable outcome of an express literal disclosure in a particular prior art document, a standard of proof much stricter than the balance of probability, to wit "beyond all reasonable doubt", needs to be applied. It follows that if any reasonable doubt exists as to what might or might not be the result of carrying out the literal disclosure and instructions of a prior art document, in other words if there remains a "grey area", then the case on anticipation based on such a document must fail" (Reasons 2.1).

3.9.7 Thus, document D3 would be novelty destroying for the subject-matter of Claim 1 provided it could be established beyond any reasonable doubt that the composition of the isocyanate B223 meets the requirements set out in Claim 1 for the isocyanate component.

3.9.8 In this connection, the Board considers it as established, in view of document D1a, in which both denominations B233 and Lupranat® M 50 are used for designating the same isocyanate product to be delivered to the client, and in view of the declaration of Mr Pohl (document D40), that the isocyanate B223 is the same product as Lupranat® M 50. This has also not been contested by the Respondent.

3.9.9 Analyses of the composition of Lupranat® M50 have been disclosed in documents D2 and D23. According to document D2 which refers to an analysis of a lot of Lupranat® M 50 produced on 27 April 1996, Lupranat® M 50 exhibits a content of 2,4' MDI of 1.5%, a content of 4,4' MDI of 28.8%, and a content of 3-ring oligomers of 31.1%. Although D2 does not indicate whether these percentages are percentage in weight, it is has been established by the declaration of Mr Jean Peeters (cf. D22) that these percentages were weight percent. This implies that according to D2, the amount of 2-ring oligomers is 30.3% by weight and the amount of 3-ring oligomers is 31.1% by weight, and hence that the ratio of 2-ring to 3-ring oligomers is 0.97. In other words Lupranat® M50 as analysed in document D2 would meet the requirements set out in Claim 1 for the isocyanate composition.

3.9.10 Document D23, which relates to an analysis of a lot of the product Lupranat® M50 produced on 7 May 1991, indicates for this product a 2-ring oligomer content of 32.1% and a 3-ring oligomer content of 27.9%, which percentages, in view of document D22, should also be regarded as percentages in weight. Consequently, Lupranat® M50 analysed in document D23 exhibits an amount of 2-ring oligomers of 32.1% by weight and a ratio of 2-ring to 3-ring oligomers of 1.15. In other words, Lupranat® M50 as analysed in document D23 would also meet the requirements set out in Claim 1 for the isocyanate composition.

3.9.11 In that context, the Board notes that the Respondent, although not having contested as such the validity of the analyses carried out in D2 and D23, has submitted that it had had no possibility to check their validity, and, taking into account the variability with time of the product Lupranat® M50 (B223), it has hence not been proven beyond any reasonable doubt that the composition of Lupranat® M50 would inevitably fall under the definition of the isocyanate composition set out in Claim 1, and that document D3 could not be considered as novelty destroying for the subject-matter of Claim 1. In order to support its argumentation in that respect, the Respondent has referred to the decision T 950/00 and to its own analyses made on the product Lupranate® M20S as disclosed in the documents D25 to D32.

3.9.12 In the case under consideration in the decision T 950/00 (Reasons point 3.1), it was considered that there was no certainty that a commercial product (i.e. Vinapas® Dispersion SAF 54) delivered on 10 September 1990 would inevitably exhibit the same property in terms of a specific parameter MFT as disclosed in a technical information leaflet of Vinapas® Dispersion SAF 54 published more than 6 years earlier, and that, in view of the very small overlap between the value of this parameter as indicated in the technical leaflet (i.e. 10 to 14ºC) and the range of this parameter claimed in the patent in suit (8 to 12ºC), it was not proven that the MFT parameter of the delivered product was inevitably in the claimed range.

3.9.13 In the present case, D2 refers to an analysis of Lupranat® M50 made less than 5 months before the publication of D3, and the results of the analysis of D23 carried out 5 years before the publication of D3 merely shows a relatively slight variation with the results indicated in D2 in respect of the amount of 2-ring isomers (32.1% instead of 30.3% and of the ratio of 2-ring oligomers to 3-ring oligomers (1.15 instead of 0.97). There is hence no evidence on file of a significant variability of the product Lupranat® M50 over years.

3.9.14 Furthermore, in contrast to the case considered in decision T 950/00 where the values of the measured parameter indicated in the prior art slightly overlapped with those required by the patent in suit, the values detected in D2 and D23 (cf. paragraphs 3.9.9 to 3.9.10, above) for the amount of 2-ring oligomers and the ratio of 2-ring to 3-ring oligomers of Lupranat® M50 (i.e. B223) are consistently clearly and indisputably within the claimed range of 12 to 42% and 0.2 to 1.8 respectively.

3.9.15 Consequently, it cannot remain, in the Board's view, any "grey area", which could cast a doubt on the fact that the isocyanate B223 used in the system Elastopor® VP H 230/008 meets the requirements set out in Claim 1 for the isocyanate composition.

3.9.16 This conclusion cannot be altered by the arguments presented by the Respondent in view of its analyses carried out by the on the product Lupranat® M20S. This is because the fact that the product Lupranat® M20S might have exhibited a such variability over years in the period 1988 (D27) to 2000 (D29) in terms of 2-ring and 3-ring oligomers content that its composition might be either inside (D32) or outside (D25 to D31) the range set out in Claim 1 of the patent in suit, is totally irrelevant to demonstrate that a different product i.e. Lupranat® M50 (B223) would also show a similar variability over years. On the contrary, as indicated above in paragraphs 3.9.9 and 3.9.10, the analyses carried out on Lupranat® M50 in D2 and D23 show a very little variation of its content of 2-ring oligomers and of its ratio of 2-ring to 3-ring oligomers, which remained steadily within the claimed ranges according to Claim 1 of the patent in suit.

3.10 Consequently, the Board comes to the conclusion that D3 is a novelty destroying document for the subject-matter of Claim 1.

3.11 The same conclusion would apply for document D36, which essentially differs from document D3 only in that the 5-component polyurethane system described therein i.e. Elastopor® EXH 1122/1, comprises as a polyol the product Elastopor® EXH 1122/1/0 instead of the Elastopor® VP H 230/008/0, and in that the amount of KX 315 in the formulation for the test reception has been set to 2.5 parts by weight instead of 2.1 parts by weight in D3.

3.12 Although for this reason alone, the main request as a whole cannot be accepted, the Board deems it appropriate to also deal with the further objection of lack of novelty of the subject-matter of Claim 5 as alleged the Appellant in view of documents D37 and D15.

3.13 Document D37, which is technical leaflet published in August 1996 (i.e. the same date as D3) referring to a five-component polyurethane system for the manufacture of rigid polyurethane foams Elastopor® VP H 230/006 consisting of:

for the polyol component (A-component)

(i) Elastopor® VP H 230/006/0 (polyol mixture without activator but with flame retardant);

(ii) Aktivator KX 315;

(iii) Zusatzmittel ZM 99; and

(iv) Treibmittel n-pentane and

for the Isocyanat component (B-component

(v) MDI (Diphenylmethanediisocyanat) (cf. D37, "Systembeschreibung").

3.14 In its Section "Eingangsprüfung" D37 discloses a formulation for the reception test of the delivered system. This composition consists of:

100,0 parts by weight of Elastopor® VP H 230/006/0;

3,1 parts by weight of KX 315;

2.2 parts by weight of ZM 99,

6,0 parts by weight of n-pentane

140,0 parts by weight of Isocyanat B223. D37 further defines the foaming characteristics which should be met by this composition (cf. "Schäumverhalten").

3.15 In this connection, the Board notes that Claim 5 of the main request requires, explicitly,

(i) that the polyisocyanate composition be reacted with an isocyanate reactive composition in the presence of a hydrocarbon blowing agent;

(ii) and that the polyisocyanate composition comprises (a) from 15 to 42 percent by weight of diphenylmethane diisocyanate, (b) three ring oligomers of polyphenylene polymethylene polyisocyanate in an amount such that the ratio of (a) to (b) is equal to from 0.2 to 1.8 and (c) higher homologues of polyphenylene polymethylene polyisocyanate.

3.16 Consequently, since n-pentane is a hydrocarbon blowing agent, and since as shown above isocyanate B223 has a composition which meets the requirements set out in Claim 5, the Board comes to the conclusion that D37 is a novelty destroying document for the subject-matter of Claim 5.

3.17 Document D15 discloses in its Examples 7 and 8 the manufacture of a rigid polyurethane foam by reacting 100 parts by weight of a polyol component, with 150 parts by weight of polyisocyanate referred as Desmodur® 44V70 in presence of 11 parts of an hydrocarbon blowing agent (n-pentane in Ex.7, Cyclopentane in Ex.8) and of 1.38 parts by weight in total of further additives (accelerators, cell regulator).

3.18 Since, however, document D15 does not explicitly disclose the composition of the isocyanate Desmodur® 44V70, the question of novelty of the subject-matter of Claim 5 over D15 boils down hence to the question as to whether it can be established using the same standard of proof as previously applied in the case of the composition of B223 (cf. paragraph 3.9.7 above), that the product Desmodur® 44V70 of Bayer AG used in the Examples 7 and 8 of D15 meets the requirements set out in Claim 5 for the isocyanate composition (cf. paragraph 3.15 (ii) above).

3.19 In that respect, the Appellant has referred to documents D38 and D39.

3.20 Document D38 is an analysis report dated 13 November 1992 which discloses, in particular, the amount of 2-ring oligomer and 3-ring oligomers of 87 charges of the MDI isocyanate Desmodur® 44V70. The authenticity of this report is certified by the declaration of Mr Udo Quade of Bayer AG (D39), in which it is further indicated that the percentages mentioned in D38 for the amount of 2-ring and 3-ring oligomers are weight percentages.

3.21 According to D38 the amount of 2-ring oligomers in the MDI product Desmodur® 44V70 varies between 31.29 (charge Nr. 2051//9D) and 41.38 % by weight (cf. charge Nr. 2019//9D) and that the ratio of 2-ring oligomers to 3-ring oligomers varies between 0.85 and 1.3 (as calculated by the Respondent and not contested by the Appellant).

3.22 It thus follows that all the values measured in document D38 for the amount of 2-ring oligomers and ratio of 2-ring to 3-ring oligomers of the product Desmodur® 44V70 are clearly inside the ranges set out for these parameters in Claim 5 of the patent in suit.

3.23 It is further noted by the Board that the date of that analysis report (i.e. 13 November 1992) is close to the filing date of D15 (26 May 1993), so that the considerations made in T 950/00 about a long period of time between the analysis and the delivery of the product (cf. paragraph 3.9.12 above) are not relevant in the present case.

3.24 Consequently, in analogy with the reasons given in the case of the composition of the isocyanate B223 (cf. paragraph 3.9.12 to 3.9.15 above), the Board comes to the conclusion that the product Desmodur® 44V70 used in D15 meets the requirements set out in Claim 5 of the patent in suit.

3.25 It thus follows from the above that document D15 is a novelty destroying document for the subject-matter of Claim 5.

First auxiliary request as submitted with the letter dated 21 September 2006 of the Respondent

4. Admissibility

4.1 Claims 1 to 9 of this first auxiliary request differ from Claims 1 to 9 of the main request, in that it has been indicated in independent Claim 1 that the reaction of the polyisocyanate composition with an isocyanate reactive composition takes place in presence of water and a hydrofluorocarbon blowing agent and in independent Claim 5 that the reaction of the polyisocyanate composition with an isocyanate reactive composition takes place in presence of water and a hydrocarbon blowing agent.

4.2 According to the Respondent, the presence of water is disclosed in paragraph [0032] of the granted patent and on page 7, lines 1 to 6 of the application as originally filed.

4.3 Independently of the fact that it is questionable, in the Board's view, as to whether this amendment is indeed supported by the application as originally filed since the passages mentioned by the Respondent appear to necessarily limit the amount of water to be added (i.e. 0.1 to 5% of the reaction system), it is in any case evident that the presence of water has not been the subject of a granted claim, in other words, the new claims 1 to 9 include subject-matter which had not previously be claimed.

4.4 It is further evident, in the Board's view, that the introduction of this feature raises new factual issues, in particular, since water, in contrast to the hydrofluorocarbon and hydrocarbon blowing agents, reacts with the polyisocyanate, and hence would modify the properties of the obtained rigid foams due to the presence of the thus formed urea bonds.

4.5 In this connection, it cannot however be concluded that all relevant prior art with respect to this aspect is on file, or that this aspect has been searched (cf. decision T 234/92 of 12 January 1995, not published in OJ EPO; Reasons point 2). Furthermore, due to the very late filing of this auxiliary request, which has furthermore been received by the Appellant only few days before the oral proceedings, it cannot be considered that the Appellant has had an opportunity to deal with this aspect, even if it might be true that the presence of water had been incorporated in Claim 5 of the first auxiliary request and in Claim 1 of the fifth auxiliary request submitted by the Patent Proprietor with its letter dated 26 August 2004 during the opposition proceedings, since these requests have not been dealt with in the decision under appeal, nor resubmitted by the Respondent in response to the Statement of Grounds of Appeal filed by the Appellant.

4.6 Consequently, the Board, in accordance with Article 10b(3) of the Rule of Procedure of the Boards of Appeal, decides not to admit the first auxiliary request submitted with letter dated 21 September 2006 into the proceedings.

First auxiliary request as submitted during the oral proceedings of 11 October 2006.

5. Admissibility

As indicated in Section VIII (d) above, the Appellant had no objection to the introduction of this request into the proceedings. Consequently, the Board sees no reason not to admit this request into the proceedings.

6. Wording of the claims

6.1 It is noted by the Board that an objection under Article 100(c) EPC has neither been raised against the granted patent by the Opponent, nor dealt with in the appealed decision.

6.2 This has as a consequence that the assessment of the allowability of the claims of the first auxiliary request under Article 123(2) EPC must be limited to that of the amendments made during the opposition and/or opposition appeal proceedings (G 9/91 OJ EPO, 1993, 420).

6.3 In this context the Board notes that Claim 1 of this request differs from Claim 1 as granted in that the features of granted Claim 2 in terms of amount of blowing agent have been incorporated therein, and that Claim 4 differs from Claim 5 as granted in that the features of granted Claim 7 in terms of amount of blowing agent have been incorporated therein.

6.4 The Board further observes that dependent Claims 2 to 3 correspond to granted Claims 3 to 4, and dependent Claims 5 to 6 correspond to granted Claims 8 to 9.

6.5 Consequently, Claims 1 to 6 are not open to objection under Article 123(2) EPC.

6.6 It is, in the Board’s view, evident that the amendments in Claim 1 in respect to granted Claim 1, i.e. the limitation of the amount of blowing agent, inevitably result in a restriction of the scope of protection with respect to granted Claim 1. The Board also comes to the same conclusion for independent Claim 4 with respect to granted Claim 5.

6.7 Thus, the Board is also satisfied that the requirements of Article 123(3) EPC are met by all the claims.

7. Novelty

7.1 As indicated above in paragraph 3.17 document D15 discloses in its Examples 7 and 8 the manufacture of a rigid polyurethane foam by reacting 100 parts by weight of a polyol component, with 150 parts by weight of polyisocyanate referred as Desmodur® 44V70 in presence of 11 parts of an hydrocarbon blowing agent (n-pentane in Ex.7, cyclopentane in Ex.8) and of 1.38 parts by weight in total of further additives (accelerators, cell regulator).

7.2 It thus follows that the amount of hydrocarbon blowing agent in Examples 7 and 8 of D15 is 4.19% by weight based on the entire reaction system used, and that document D15 must be also considered as a novelty destroying document for the subject-matter of Claim 4 of this first auxiliary request.

7.3 Consequently, the first auxiliary request filed during the oral proceedings of 11 October 2006 must be refused.

Second auxiliary request as submitted during the oral proceedings of 11 October 2006.

8. Admissibility

8.1 Claims 1 to 6 of the second auxiliary request differ from Claim 1 to 6 of the first auxiliary request submitted during the oral proceedings of 11 October 2006, in that it has been indicated in independent Claim 4 that the polyisocyanate composition comprises 20 to 40 percent by weight of diphenylmethane diisocyanate.

8.2 According to the Respondent, this specific range is disclosed in paragraph [0015] of the granted patent and on page 5, lines 9 to 13 of the application as originally filed.

8.3 While this specific range of the amount of diphenylmethane diisocyanate in the polyisocyanate composition has not been the subject of a granted claim, the introduction of this feature does not raise, in the Board's view, new factual issues, since the amount of diphenylmethane diisocyanate in the polyisocyanate composition was already a feature of the granted patent, and since this restricted range has not been associated with any specific technical effect in the application as originally filed. The introduction of this restricted range hence merely amounts to an arbitrary limitation of the originally claimed and searched range in order to try to overcome the objection of lack of novelty over D15.

8.4 Under these circumstances, it could hence reasonably be expected that the Appellant could deal with the subject-matter of the second auxiliary request, despite the fact that this request had been submitted at a very late stage of the appeal proceedings, i.e. at the oral proceedings before the Board.

8.5 Consequently, the Board decides to admit the second auxiliary request into the proceedings.

9. Wording of the claims

9.1 As indicated above in paragraph 8.1, Claims 1 to 6 of the second auxiliary differ from Claims 1 to 6 of the first auxiliary request only in that amendments concerning the polyisocyanate composition have been carried out in Claim 4 thereof.

9.2 Since, as also submitted by the Respondent, these amendments are supported by the application as originally filed (cf. page 5, lines 9 to 13), the Board comes to the conclusion that the second auxiliary request meets the requirements of Article 123(2) EPC.

9.3 It is, in the Board’s view, evident that the amendments in Claim 4 in respect to granted Claim 5, i.e. the limitation of the amount of blowing agent and the limitation of the content of diphenylmethane diisocyanate in the polyisocyanate composition inevitably result in a restriction of the scope of protection in respect to granted Claim 5.

9.4 Thus, the Board is satisfied that the requirements of Article 123(3) EPC are met by all the claims.

10. Novelty of the subject-matter of Claim 1

10.1 Claim 1 of the second auxiliary request differs from Claim 1 as granted in that the amount of hydrofluorocarbon blowing agent has been limited to 2 to 20% by weight based on the entire reaction system.

10.2 While documents D3 and D36 have been considered as novelty destroying for the subject-matter of granted Claim 1, the Board observes that in the respective sections "Verarbeitung" of these documents it is merely indicated that the blowing agent R 134a should be used in amount of 2 to 3 parts by weight per 100 parts by weight of the respective polyol component. Since, according to the test composition used for reception purposes of the polyurethane systems disclosed in these documents, the amount of the polyisocyanate is 133 parts for 100 parts of the polyol component it is evident that the amount of blowing agent R 134a would be in any case below 2% by weight based on the entire reaction system.

10.3 Consequently, the subject-matter of Claim 1 must be regarded as novel over the cited prior art.

11. Inventive step

12. The patent in suit is concerned with a process which utilizes a specific polymeric polyisocyanate component for the production of rigid polyurethane foams with hydrofluorocarbon blowing agent.

12.1 Such a process is known from documents D3 and D36.

12.2 The technical problem with which the patent in suit was originally concerned was to provide a process for the manufacture of hydrofluorocarbon blown rigid polyurethane foams having improved physical (i.e. compressive strength, dimensional stability) and thermal insulation properties. It was suggested that this was achieved by using a specific polymeric polyisocyanate composition (cf. patent in suit paragraphs [0009] and [0010]). In that respect, Example 2 of the patent specification relies on a comparison between hydrofluorocarbon blown rigid polyurethane foams using different polymeric MDI polyisocyanate in order to demonstrate the effect of the specific composition of the polymeric polyisocyanate according to the patent in suit on the physical and thermal properties of the obtained foams.

12.3 However, as stated in decision T 20/81 (OJ EPO 1982, 217) the nature of the problem should be determined on the basis of objective criteria, and this requires the assessment of the technical effect vis-à-vis the closest state of the art.

12.4 In this connection, it is noted by the Board that the subject-matter of Claim 1 differs from the disclosure of D3 and D36 only in that a higher amount of hydrofluorocarbon blowing agent is used in the claimed process.

12.5 Although D3 and D36 do not expressly refer to the mechanical and thermal properties of the obtained rigid foams, the foams disclosed therein are used in building and insulation materials (cf. D3 and D36, paragraph "Anwendungszweck"), so that there can be no doubt that D3 and D36 are indeed also concerned with these properties, and hence with a similar technical problem as the patent in suit.

12.6 This implies that the technical problem, which has been originally formulated in the patent in suit, has been stated in respect of a prior art which was far more remote than the one represented by documents D3 or D36.

12.7 This further implies that the technical problem underlying the patent in suit must be reformulated starting from D3 or D36 as closest state of the art.

12.8 In this connection, the Board notes that no comparison between the polyurethane rigid foams obtained according to the process of Claim 1 and those obtained according to D3 or D36 has been made in the patent in suit or submitted by the Respondent (Patent proprietor).

12.9 Nevertheless, it is well known that the increase of the amount of blowing agent has predictable consequences on the density of the rigid polyurethane foams (cf. for example D43, page 4, paragraph "Blowing agent"), so that a reformulated problem consisting in the production of rigid polyurethane foams of lower density than those obtained according to D3 and D36 could be deduced by the skilled person from the patent in suit in relation to this closest prior art (cf. also T 386/89 of 24 March 1992, not published in OJ EPO; Reasons point 4.3).

12.10 In that context, taking into account the predictable effect of the increase of the amount of blowing agent on the density of the rigid polyurethane foams, the absence of evidence of a particular effect of the choice of the range of amount of hydrofluorocarbon blowing agent (i.e. between 2 and 20% by weight), and the further fact that amounts such as 13% and 20% by weight of hydrofluorocarbon blowing agent are usual for the manufacture of rigid polyurethane foams (cf. document D8, Tables 6 and 13), the Board can only come to the conclusion, that the subject-matter of Claim 1 must be considered as obvious starting from D3 or D36 as closest prior art (Article 56 EPC).

12.11 Consequently, the second auxiliary request must be refused.

Third auxiliary request submitted at the oral proceedings of 11 October 2006

13. Admissibility

13.1 According to several decisions of the Boards of Appeal (e.g. T 153/85 (OJ EPO 1988, 001); T 955/91 of 4 February 1993 (not published in OJ EPO)), a Board may justifiably refuse to consider alternative claims which have been filed at a very late stage, if such alternative claims are not clearly allowable. However, as stated in decision T 577/97 of 5 April 2000 (not published in OJ EPO), the discretion not to admit auxiliary requests should in principle be limited to exceptional cases.

13.2 As indicated above in Section VII (d), Claim 1 of the third auxiliary request is the same as Claim 1 of the second auxiliary request. As stated above in paragraph 12.10, Claim 1 of the second auxiliary request does not however meet the requirements of Article 56 EPC.

13.3 It follows that Claim 1 of the third auxiliary request is not merely "not clearly allowable" but, in contrast, clearly not allowable under the provisions of Article 56 EPC. Thus, in the Board's view, this situation justifies the Board to exercise its discretion not to admit this late filed request.

13.4 Consequently, the third auxiliary request is not admitted into the proceedings.

14. Since, none of the requests presented by the Respondent can be granted, the patent must be revoked.