T 1926/08 03-05-2011

Reasons for the Decision

1. The appeals are admissible.

Admissibility of the main request

2. The claims of both sets of the main request filed with letter of 20 April 2011 differ from the claims of the two sets of the main request underlying the appealed decision only in that a number of dependencies not appearing in the claims as granted and some repetitions in the dependent claims have been deleted, so as to render moot some objections under Rule 80 EPC which had been raised by the appellants.

2.1 Since they do not involve any change in the independent claims, they do not change the analysis related to the requirements of Article 123(2) EPC, sufficiently of disclosure, novelty and inventive step. On this basis they do not require any additional effort to be dealt with and they do not raise therefore any issue which the Board or the appellants cannot be expected to deal without adjournment of the oral proceedings (Article 13(3) of the Rules of Procedure of the Boards of Appeal).

2.2 In view of this the Board admits the main request filed with letter of 20 April 2011 into the proceedings.

Admissibility of two sets of claims for different contracting states

3. D1 is a European patent application with a validly claimed priority date (its priority document is identical to the application as filed) which is prior to the priority date of the patent in suit and a publication date which is after the filing date of the patent in suit. It belongs therefore to the state of the art under Article 54(3) EPC.

3.1 The present patent was granted before the date of entry into force of the EPC 2000. By virtue of Article 1 of the Decision of the Administrative Council of 28 June 2001 on the transitional provisions under Article 7 of the Act revising the EPC of 29 November 2000 (Special edition No.1 of OJ EPO 2007, 197), Article 54(4) EPC 1973 still applies.

3.2 According to Rule 23a EPC 1973, which is an implementing regulation of Article 54(4) EPC 1973, D1 is only state of the art with respect to novelty for the common contracting states for which the designation fees have been validly paid (BE, DE, ES, FR, GB, NL). In order to establish novelty with respect to document D1 the patent proprietors filed a first set of claims for these states and a second set for the further contracting states designated in the patent in suit (CH, DK, LI, LU). Since the admissibility of a second set of claims has been objected to by the opponents, the legal framework relating to the possibility of filing different claims, description and drawings for different states needs to be analysed.

3.3 Article 2, first sentence, of the Administrative Council's decision of 7 December 2006 amending the Implementing Regulations to the EPC 2000 (Special edition No.1 of OJ EPO 2007, 89) reads: "The Implementing Regulations to the EPC 2000 shall apply to all European patent applications, European patents, ..., in so far as the foregoing are subject to the provisions of the EPC 2000."

3.4 In decision J 10/07 (OJ EPO 2008, 567) the Legal Board of Appeal stated that this can only mean that a Rule of the Implementing Regulations to the EPC 2000 is to be applied where, or in so far as, the European patent application in question is subject to the Article of the EPC 2000 to which that Rule relates and which is specified and supplemented by it. Otherwise, irresoluble contradictions and legal discrepancies would arise between the applicable Articles of the EPC 1973 and the applicable provisions of the Implementing Regulations to the EPC 2000, which cannot have been the legislator's intention (point 1.3 of the Reasons).

3.5 In J 3/06 (supra) the Legal Board stated further that in an assessment of which Article relates to a particular Rule, it should be noted that a Rule in the Implementing Regulations can affect different EPC Articles in very different ways. Within the meaning of the provision, a Rule does not apply to an Article purely by virtue of mentioning that Article. However, a Rule in the Implementing Regulations can be assumed to apply to a particular EPC 2000 Article when it puts a more detailed construction on that Article, in keeping with the purpose of "implementing" the EPC (point 3 of the Reasons).

3.6 According to Article 7 of the Act revising the EPC (Special edition No.1 of OJ EPO 2007, 196) in connection with the Administrative Council's decision of 28 June 2001 on the transitional provisions (supra), Article 54(4) EPC 1973 shall continue to apply to European patents granted before 13 December 2007, while Article 123 EPC 2000 is applicable to patents granted before that date. This has not been contested. The point of dispute rather is whether or not Rule 87 EPC 1973 is a Rule implementing Article 54(4) EPC 1973 and consequently could be applied, or whether the situation is covered by Article 123 and Rule 138 EPC. Indeed Rule 87 EPC 1973 allows different claims, description and drawings for different states both in the case of an earlier European patent application which is part of the state of the art under Article 54(3) and (4) EPC 1973 and when a prior national right exists, while Rule 138 EPC 2000 foresees only the latter case.

3.7 As set out by the Legal Board of Appeal, a Rule can affect different Articles and this Board does not deny that Rule 87 EPC 1973 also affects Article 123 EPC. However the clear purpose of Rule 87 EPC 1973 is to take account of the situation that a conflicting application constitutes prior art only for some and not for all designated states. It governs the procedure when this situation arises and thus is clearly linked to Article 54(4) EPC 1973. A Rule does not only implement an Article when it defines its substance in more detail, like Rule 23a EPC 1973 does by setting up a condition for the territorial scope of the conflicting application, but also when it provides a procedure to enforce the substance of the Article.

3.8 If one did not allow a separate set of claims, the patent proprietor would have to limit his patent for all designated states. This would mean that the conflicting application had effect for all designated states. This is the situation under the EPC 2000 which, however, in the present case is not yet applicable. Not providing a procedure to enforce what is laid down in Article 54(4) EPC 1973 is in contradiction to the legislator's intention because it would make Article 54(4) EPC 1973 redundant. Thus Rule 87 EPC 1973 is applicable and a separate set of claims for the contracting states CH, DK, LI and LU is admissible.

Referral to the Enlarged Board of Appeal

4. According to Article 112(1)(a) EPC 1973 EPC the Board of Appeal shall refer a point of law to the Enlarged Board of Appeal in order to ensure uniform application of the law or if a point of law of fundamental importance arises and if it considers that a decision of the Enlarged Board is required.

4.1 Appellants 01 seem to suggest that coming to the conclusion that Rule 87 EPC 1973 was a Rule implementing Article 54(4) EPC 1973 instead of Article 123 EPC was contradictory to the jurisprudence of the Legal Board of Appeal in J 3/06 (supra). The Board does not see such a contradiction. In J 3/06 (loc. cit.) the Legal Board clearly said that a Rule can affect different EPC Articles and that a Rule can be assumed to apply to a particular Article when it puts a more detailed construction on that Article, in keeping with the purpose of "implementing" the EPC. The present Board followed this line and came to the conclusion that the purpose of Rule 87 EPC 1973 is to provide a procedure for the situation underlying Article 54(4) EPC 1973 and thus implements this Article. Furthermore, from this it follows that the questions appellant 01 wanted to have referred to the Enlarged Board of Appeal are irrelevant because they concern Article 123 EPC which does not play a role for answering the relevant question of whether or not a separate set of claims is admissible.

4.2 For these reasons, the Board does not consider that a decision of the Enlarged Board of Appeal is required.

Amendments - Rule 80 and Article 123(2) EPC

5. The patent proprietors decided to amend all independent claims by specifying that some tetra-alkylammonium hydroxide remains in solution in the suspension resulting from the synthesis of zeolite and argued that the amendment played a role for the inventiveness of the claim. This was objected to by the opponents, who considered this feature as implicit in the claimed process.

5.1 The Board considers that there is no evidence either based on the patent in suit or on the available prior art, which could lead to the conclusion that such a feature is already necessarily implied by the wording of the claim. In particular, the claim does not specify that tetra-alkylammonium hydroxide needs to be present in excess in the reagent mixture used for the synthesis of zeolite. Moreover, the passages of D2 and D6 cited by the opponents (see D2, column 3, line 27 and D6, page 234, Chemical composition) refer to zeolites with a specific chemical composition which implies a specific quantity of tetra-propylammonium hydroxide, but they do not contain any general information which allows to determine what happens in the reacting systems defined in the independent claims of the main request.

5.2 The specification that some tetra-alkylammonium hydroxide remains in solution in the suspension resulting from the synthesis of zeolite constitutes therefore a limiting amendment occasioned by a ground of opposition (lack of inventive step) and cannot be objected to under Rule 80 EPC.

5.3 Once this has been established, the specific way in which the limitation is expressed (in particular by defining the essential ingredients of the suspension through the wording "containing zeolite crystals and tetraalkylammonium hydroxide remaining in solution") lies within the discretion of the proprietor and cannot be objected to either under Rule 80 EPC. The same applies to further minor amendments which are a consequence of the main amendment, namely the addition of the word "suspension" and "said suspension" which are necessary to keep the meaning of the claim clear after the term "suspension" and the relative pronoun "to which" have been separated by means of the amendment.

5.4 The requirements of Rule 80 EPC are therefore met.

6. Claim 1 of the first set corresponds to original claim 3 (dependent on original claim 1) with the addition that the suspension resulting from the synthesis of the zeolite contains "zeolite crystals and tetraalkylammonium hydroxide remaining in solution" and that the rapid drying is "effected by feeding to a spray-drier".

6.1 The original description discloses in its general part that "zeolite crystals and tetraalkylammonium hydroxide remaining in solution, are present" in the suspension resulting at the end of the synthesis (page 4, lines 9 to 12) and that the "rapid drying of the suspension is preferably carried out by feeding to a spray-drier" (page 6, lines 18 to 19). These specifications apply to all embodiments of the invention, so that claim 3 in combination with the cited passages of the description gives an unambiguous basis for claim 1 of the first set.

7. Similarly claims 3, 4, 5 and 6 of the first set are based on original claims 7, 8, 11 and 14 respectively (all dependent on claim 1) in combination with the above cited passages on pages 4 and 6 concerning the presence of tetra-alkylammonium hydroxide in solution and the accomplishment of the rapid drying by feeding to a spray-drier.

7.1 The fact that claim 1 of the first set was limited to a specific quantity of tetra-alkylorthosilicate to be added to the suspension with the intention to establish novelty with respect to D1 (see point 9.2 below) does not change the fact that original claim 1 as well as original claims 7, 8, 11 and 14, which together with the above cited passages on pages 4 and 6 give a basis to claims 3, 4, 5 and 6 of the first set respectively, were not limited with respect to the quantity of tetra-alkylorthosilicate to be added to the suspension. The absence of such a limitation in claims 3, 4, 5 and 6 of the first set does not give rise therefore to any infringement of the requirements of Article 123(2) EPC.

7.2 The passage in the original description on page 6, lines 8 to 13, which specifies that when "tetra-alkylorthosilicate is added to the suspension resulting from the synthesis of zeolite, before this is subjected to rapid drying, it will be added in a quantity ranging from 0.08 to 0.50 moles per 100 grams of zeolite contained in the suspension" is not in agreement with amended claims 3, 4, 5 and 6 of the first set. Its deletion in paragraph [0006] of the version of the description adapted to the first set is therefore a correct adaptation, which does not result in any infringement of the requirements of Article 123(2) EPC.

Sufficiency of disclosure

8. The allegation of the appellants that the invention was not sufficiently disclosed with reference to the spray-drying step and to the presence of tetra-alkylammonium hydroxide remaining in solution at the end of the zeolite synthesis was not supported by any facts.

8.1 Spry-drying is a known and common technique in the field of zeolite production and no evidence was provided that it should pose technical difficulties to the skilled person, so as to result in an undue burden. Moreover, the specific dimensions of the microspheres, which have been cited by the opponents as requiring additional technical information to be obtained, do not appear as a required product feature in any of the claims.

8.2 As to the tetra-alkylammonium hydroxide remaining in solution at the end of the zeolite synthesis, this feature can only be understood as corresponding to the use of the templating agent in excess during the synthesis step (see paragraph [0005] in the patent). If this is done, some tetra-alkylammonium hydroxide will necessarily remain in solution at the end of the synthesis.

8.3 For these reasons, it is considered that the objections under Article 100(b) EPC are not well founded.

Novelty

9. Document D1 is prior art under Article 54(3) EPC and by virtue of Article 54(4) and Rule 23a EPC 1973 (see point 3 above) it is only relevant for the common contracting states for which the designation fees have been validly paid, namely BE, DE, ES, FR, GB, NL. Therefore, it belongs to the state of the art only as far as novelty of the claims of the first set is concerned.

9.1 Since it is not relevant for inventive step, a full analysis of the document is not necessary in the present decision, but it is sufficient to determine whether there is at least one feature in each of the independent claims of the first set which have been attacked by the opponents under lack of novelty (claims 1 and 4), which is not disclosed in D1.

9.2 With regard to claim 1 of the first set, the quantity of tetra-alkylorthosilicate to be added to the suspension resulting from the synthesis of zeolite has been identified by the parties as the disputed feature.

9.2.1 D1 discloses that binders or pore producers such as tetra-alkylorthosilicate, silica sol, pyrogenic silica (Aerosil), tetra-n-propylammonium hydroxide, tylose and pentaerythritol may be added to the suspension resulting from the synthesis of zeolite (page 3, lines 54-56). No other passage is present in D1 referring to the addition of tetra-alkylorthosilicate, nor any tetra-alkylorthosilicate is added to the suspension resulting from the synthesis of zeolite in the examples.

9.2.2 Therefore no range is disclosed in D1 related to the quantity of tetra-alkylorthosilicate to be added. This cannot be interpreted as the implicit disclosure of a very broad range from which a sub-range has been chosen in claim 1 of the first set, since tetra-alkylorthosilicate is a minor ingredient for which no indication has been given and any choice of a (broad or narrow) range would be an activity of the person skilled in the art, which goes beyond the direct and unambiguous disclosure in the document.

9.2.3 The specification that the tetra-alkylorthosilicate is added in a quantity ranging from 0.08 to 0.50 moles per 100 grams of zeolite contained in the suspension resulting from the synthesis in claim 1 of the first set is therefore not to be seen as the selection of a sub-range out of a previously known range, but as the addition of a limiting feature, which was not disclosed in D1 and is sufficient to provide novelty.

9.3 With regard to claim 4 of the first set, the disputed features concern the ranges for the Si/Ti and the H2O/Si ratios in the reacting mixture for the synthesis of zeolite.

9.3.1 D1 does not disclose any detail of the quantities of the components present in the reacting mixture in the general part of the description. The only example in which a synthesis mixture according to the invention of D1 is described is example 3 of D1, which refers to example 1 of D2, as far as the synthesis mixture is concerned.

9.3.2 Since example 3 of D1 contains a specific reference to example 1 of D2, in accordance with the case law (see Case Law of the Boards of Appeal of the EPO, 6th edition 2010, I.C.3.1) only the part of D2 corresponding to that specific reference (example 1) is to be considered as part of the disclosure of D1.

9.3.3 Both parties agreed, however, that the values of the Si/Ti and H2O/Si ratios of example 1 of D2 are outside the ranges in claim 4 of the first set.

9.3.4 This is true without doubts for the Si/Ti molar ratio which derives from 455 g of tetra-ethylorthosilicate and 15 g of tetra-ethyltitanate (D2, column 4, lines 1 to 6), which corresponds to a molar ratio of 33.2 (as computed by the patent proprietors by taking into account the molecular weight of tetra-ethylorthosilicate and tetra-ethyltitanate, see their statement setting out the grounds of appeal, page 35, and not disputed by the opponents). On this basis it must be concluded that D1 does not disclose directly and unambiguously at least values of the Si/Ti ratio in the reacting mixture for the synthesis of zeolite falling within the range of claim 4 of the first set.

9.3.5 Since a difference has been identified, it is not necessary to enquire whether also the H2O/Si ratio of example 1 of D2, whose computation requires the understanding of what happens during the heating and evaporation step of the initial mixture before mixing with further water to obtain the reacting mixture (D2, column 4, lines 6-14), also falls outside the range of claim 4 of the first set.

9.4 For these reasons, both claim 1 and claim 4 of the first set are novel with respect to the disclosure in D1.

9.5 No other objection of lack of novelty was raised by the opponents and no other document was cited with respect to novelty. This issue (in particular with regard to the claims of the second set) does not need therefore any further consideration by the Board.

Inventive step

10. Inventive step of the process of claim 1 according to the second set is analysed first, since this claim covers the broadest scope of protection.

10.1 With respect to this claim, which concerns a process for the preparation of zeolitic catalysts in the form of microspheres, comprising zeolite and oligomeric silica, all parties considered D7 as the closest state of the art. The Board sees no reason to depart from this choice.

10.2 Document D7 relates to bonded zeolites and to a process for producing them (page 2, line 1) and discloses a process for producing zeolites bonded with oligomeric silica, comprising mixing a suspension of said zeolite in water with an aqueous solution of oligomeric silica and alkyl-ammonium hydroxide, and submitting to quick drying the so-obtained suspension, whereby the suspension and the solution have specific compositions and the zeolites are selected from:

1) a calcined and anhydrous zeolite,

2) a calcined, anhydrous zeolite preferably exchanged with ammonium ions,

3) a damp zeolite containing as the counter-cations, ammonium or alkyl-ammonium cations, optionally in the presence of an excess of the related hydroxides, as it is obtained by means of a hydrothermal treatment, without carrying out a final calcination thereof (claim 1 and page 2, lines 8 to 22).

10.2.1 The solution is prepared in particular by hydrolysing in the liquid phase a tetra-alkylorthosilicate in an aqueous solution of alkyl-ammonium hydroxide (page 2, lines 28 to 31), which is preferably tetra-propylammonium hydroxide (page 2, lines 25-27). In all the examples disclosing bonded zeolites (examples 2, 4, 6, 8, 9, 11, 13 and 15 on pages 8 to 13) quick drying is accomplished by feeding the suspension to a spray-drier, thereby obtaining compact microspheres, and calcining the atomised product.

10.2.2 Examples of damp zeolites as obtained by means of a hydrothermal treatment without carrying out the final calcination thereof according to the third embodiment of claim 1 of D7 are given (pages 8 to 13) in examples 1, 3, 5, 10, 12 and 14 (preparation of the zeolites) in combination with examples 2, 4, 6, 11, 13 and 15 respectively (preparation of the bonded zeolites). In all cases hydrothermal treatment at autogenous pressure of a reagent mixture containing tetra-alkylammonium hydroxide as templating agent is accomplished for the crystallization of the zeolite followed by centrifugation, washing by dispersion in water and re-centrifugation. It is then the washed centrifugation cake which is dispersed into a clear solution of tetra-ethylorthosilicate and tetra-propylammonium hydroxide to obtain the suspension which is subjected to spray-drying.

10.3 The suspension which is subjected to spray-drying in D7 contains therefore zeolite crystals, tetra-alkylammonium hydroxide in solution and tetra-alkylorthosilicate as the suspension subjected to spray-drying of the process of claim 1 of the first set, but contrary to that it does not result from the synthesis of the zeolite by hydrothermal treatment at autogenous pressure of the reagent mixture containing tetra-alkylammonium hydroxide as templating agent with the optional addition of tetra-alkylorthosilicate, but from the dispersion of a washed centrifugation cake from a zeolite synthesis into a solution of tetra-alkylorthosilicate and tetra-alkylammonium hydroxide.

10.4 It is the object of the patent in suit to provide a simplified process for preparing catalysts comprising zeolites and oligomeric silica having a high mechanical resistance (paragraph [0003] in the patent).

10.4.1 There can be no doubts that the claimed process represents a simplification with respect to the process of D7. No treatment of the suspension resulting from the synthesis of zeolite and no further addition of a solution of tetra-alkylorthosilicate and tetra-alkylammonium hydroxide is indeed necessary. As to the mechanical resistance of the bonded zeolitic catalyst, while it is true that no data are available which allow a comparison between the mechanical resistance of the claimed catalyst with that of the product of D7, in examples 1 to 3 of the patent in suit the particle distribution of the microspheres obtained by the claimed process has been measured at the end of the production process and after treatment for one hour in ultrasounds and it has been observed that the particle distribution is not modified after the ultrasound treatment, so as to allow to conclude that the catalyst has good mechanical resistance.

10.5 The technical problem to be solved with respect to D7 can thus be seen as the provision of a simplified process for preparing catalysts comprising zeolites and oligomeric silica having a satisfactory mechanical resistance. Having regard to the available information, the Board is convinced that the problem has been solved by the subject-matter of claim 1 of the second set.

10.6 Document D5 discloses a method for preparing an inorganic oxide matrix bound porous crystalline silicate comprising preparing said silicate from a reaction mixture which comprises a source of silicon and water, thereafter adding to said reaction mixture which contains unincorporated silica, as well as the crystalline silicate, an inorganic oxide matrix precursor comprising a source of inorganic oxide matrix and water and drying the resulting mixture to produce an inorganic oxide matrix-bound porous crystalline silicate (column 3, lines 6 to 17). By this method, unincorporated silica in the reaction mixture is incorporated in the inorganic oxide matrix (column 3, lines 17 to 19).

10.6.1 The drying step can be accomplished by any suitable means, such as spray-drying (column 3, lines 38 to 42). Any suitable organic directing agent may be used, n-alkylamine being particularly preferred (column 3, lines 33 to 35). Generally, the organic directing agent employed in the zeolite formation can be essentially removed by any suitable technique prior to adding said matrix precursor, e.g. by flashing (column 3, lines 44 to 47).

10.7 While the idea of using unincorporated silica from the synthesis mixture may be found in D5, addition of a further source of inorganic oxide matrix and water is a necessary step of the process disclosed therein. Moreover, an organic agent is not necessarily present and, in case it is, it is generally removed before the addition of the matrix precursor (and therefore before spray-drying). In addition, tetra-alkylammonium hydroxides are not mentioned in D5.

10.8 In view of this a hint cannot be found in D5 that in order to solve the posed problem the suspension resulting from the zeolite synthesis of D7 and containing tetra-alkylammonium hydroxide in solution can be directly fed to spray-drying without the addition of a solution of tetra-alkylorthosilicate and tetra-alkylammonium hydroxide (which is a compulsory step in D7) and with the optional addition of tetra-alkylorthosilicate alone.

10.9 Such a hint cannot be found in D16, D17 and D18 either.

10.9.1 D16 discloses a process involving admixture of an aqueous slurry comprising a cogel of hydrous silica and one or more hydrous metal oxides, preferably a silica-alumina cogel, with the mother liquor containing precipitated zeolite crystals obtained from a zeolite crystallization step, and the subsequent evaporation of water, e.g. by spray-drying, from the resulting fluid slurry mixture to form the desired zeolite-cogel matrix composite product comprising zeolite crystals embedded in the desired cogel (column 3, lines 6 to 17). In this way, a distinct separation of the zeolite product crystals from their mother liquor is not required (column 2, line 68 to column 3, line 1).

10.9.2 D17 discloses a process for producing catalysts including a crystalline aluminosilicate zeolite dispersed in an inorganic oxide matrix (page 1, first paragraph), comprising mixing silica, aluminium oxide, sodium oxide and water with zeolite crystallisation seeds, allowing crystallisation of the zeolite, diluting with water, mixing with an acid component in order to cause gelification of the sodium silicate and spray-draying the gelled composition in order to obtain the desired particles (page 3, last paragraph to page 5, first paragraph). In this way the unreacted materials of the reaction mixture are transformed into a gel (page 3, first paragraph).

10.9.3 D18 discloses a process for preparing granulated components based on zeolites for synthetic surfactants including mixing of solutions of sodium silicate and sodium aluminate, hydrothermal crystallisation of the obtained aluminosilicate-hydrogel und spray-drying of the zeolite suspension in its mother liquor (claim 1, German translation).

10.10 While the idea of spray-drying the mother liquor of a zeolite synthesis process can be found in these documents (admixed with a silica-alumina cogel in D16 and after gelification in D17), none of them discloses a synthesis process including organic templating agents as the one of claim 1 of the second set and the one disclosed in D7. Their teaching therefore cannot be applied to D7 and cannot hint to the direct feeding to spray-drying of the suspension resulting from the zeolite synthesis of D7 and containing tetra-alkylammonium hydroxide in solution without the addition of a solution of tetra-alkylorthosilicate and tetra-alkylammonium hydroxide (which is a compulsory step in D7).

10.11 For these reasons, the process of claim 1 of the second set involves an inventive step having regard to the available prior art.

10.12 Claims 1, 3, 4, 5 and 6 of the first set concern processes for the preparation of zeolitic catalysts in the form of microspheres, which include all the features of the process of claim 1 of the second set together with further limitations. They involve therefore an inventive step a fortiori for the same reasons as detailed for claim 1 of the second set (see points 10.1 to 10.11 above).

Adaptation of the description

11. An adaptation of the description took place before the opposition division in view of the main request underlying the decision under appeal. Since the main request which has been analysed in the present decision differs from that main request only in minor amendments in the dependent claims, there is no need for a further adaptation.

11.1 The only objection to the adaptation of the description raised by the opponents has already been dealt with while analysing the amendments (see point 7.2 above) and has lead to the conclusion that the requirements of the EPC are met. No further analysis of the adapted description is therefore necessary.