T 1733/06 28-08-2009

I. The grant of European patent No. 0 513 380 in respect of European patent application No. 91 920 770.4, filed on 29 November 1991 as International patent application No. PCT/JP91/01658 and claiming the priorities of two earlier applications filed in Japan (329539/90 and 103754/91) of 30 November 1990 and 9 April 1991, respectively, was announced on 1 October 1997 (Bulletin 1997/40). The patent was granted with eight claims. Independent Claim 1 read as follows:

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

The remaining process claims 2 to 8 were all dependent.

In this decision, any reference to passages in the patent in suit as granted will be given underlined in squared brackets, eg [Claim 1] or [0001]. References in underlined italics concern passages in the English translation of the application as filed, eg page 1, lines 8 to 11. "EPC" refers to the revised text of the EPC 2000, the previous version is identified as "EPC 1973".

II. On 29 and 30 June 1998, respectively, two Notices of Opposition by Opponents O-01 and O-02 were filed, in each of which revocation of the patent in its entirety was requested. Both Opponents asserted lack of novelty and lack of inventive step, whereby O-01 invoked Articles 54 and 56 EPC 1973 and O-02 Articles 100(a) and 52 to 57 EPC 1973. The oppositions relied on altogether ten documents, including

D1: WO-A-91/14713

D3: EP-A-0 277 004,

D4: EP-A-0 260 130 and

D7: EP-A-0 287 666.

(1) On 6 September 2006, oral proceedings were held before the Opposition Division on the basis of a Main and ten Auxiliary Requests of the Patent Proprietor.

(2) The Main Request was directed to the maintenance of the patent in suit as granted. New sets of claims according to Auxiliary Requests 1 to 6 and further amended Auxiliary Request 8 were filed during the oral proceedings, whereas the sets of claims according to Auxiliary Requests 7, 9 and 10 had already been submitted with a letter dated 12 August 2005. Only Auxiliary Request 8 played a role in the appeal proceedings before this Board. Its (sole) Claim 1 as amended at those oral proceedings read as follows:

"A process for producing an olefin based polymer in which is carried out a homopolymerization of an alpha-olefin or a copolymerization of two or more alpha-olefins of the formula (XIII)

R**(13)-CH=CH2 (XIII)

wherein R**(13) represents a hydrogen atom or an alkyl group having 1 to 28 carbon atoms;

the process is carried out in the presence of a catalyst comprising as main components the following components (a), (b) and (c):

(a) a transition metal compound of formulas (i) to (IV)

| CpM**(1)Ra**(1)Rb**(2)Rc**(3)| (i) |

| | |

| | |

| Cp2M**(1)Ra**(1)Rb**(2)| (II) |

| | |

| | |

| (Cp-Ae-Cp)M**(1)Ra**(1)Rb**(2)| (III) |

| | |

| | |

|M**(1)Ra**(1)Rb**(2)Rc**(3)Rd**| (IV), |

|(4) | |

| | |

wherein M**(1) is a Ti, Zr or Hf atom; Cp is a group selected from a cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclo pentadienyl group, isopropylcyclopentadienyl group, 1,2-dimethyl cyclopentadienyl group, tetramethylcyclopentadienyl group, 1,3-di methylcyclopentadienyl group, 1,2,3-trimethylcyclopentadienyl group, 1,2,4-trimethylcyclopentadienyl group, trimethylsilylcyclo penta dienyl group, indenyl group, substituted indenyl group, tetrahydro indenyl group, substituted tetrahydroindenyl group, fluorenyl group or substituted fluorenyl group; for compounds of formula (i), (II), (III) and (IV) R**(1), R**(2), R**(3) and R**(4) are independently a hydrogen atom, oxygen atom, C1-20 alkyl group, C1-20 alkoxy group, C6-20 aryl group, alkylaryl group or arylalkyl group, C1-20 acyloxy group, allyl group, substituted allyl group, a substituent containing a silicon atom, an acetylacetonato group or substituted acetylacetonato group;

A is a bridge based on a covalent bond; a , b and c represent independently in formula (i) an integer of 0 to below 4, a and b represent independently in formulas (II) and (III) an integer of 0 to 2; in formula (IV) a, b, c and d are independently an integer of 0 to 4; e is an integer of 0 to 6; and two or more of R**(1), R**(2), R**(3) and R**(4) may form a ring, and in formulas (II) and (III) two Cp may be the same as or different from each other;

(b) is a compound of formulas (VIII) or (IX)

|([L**(l)-R7]**(k+)p([M**(3)Z**(| (VIII) [sic] |

|1)Z**(2)....Z**(n](n-m)-)q | |

| | |

| (IX) |

| | |

| | |

wherein L**(2) is M**(5), R**(8)R**(9)M**(6), R**(10)3C or R**(11)M**(6); L**(1) is a Lewis base; M**(3) and M**(4) are independently an element selected from the groups IIIA, IVA and VA of the Periodic Table; M**(5) and M**(6) are independently an element selected from the groups IIIB, IVB, VB, VIB, VIIB, VIII, IA, IB, IIA, IIB and VIIA of the Periodic Table; Z**(1) to Z**(n) are independently a hydrogen atom, dialkylamino group, C1-20 alkoxy group, C6-20 aryl oxy group, C1-20 alkyl group, C6-20 aryl group, alkylaryl group or arylalkyl group, C1-20 halogenated hydrocarbon group, C1-20 acyl oxy group, organometalloid group or halogen atom; two or more of Z**(1) to Z**(n) may form a ring; R**(7) is C1-20 alkyl group, C6-20 aryl group, alkyl aryl group or arylalkyl group; R**(8) and R**(9) are independently a cyclo pentadienyl group, substituted cyclopentadienyl group, indenyl group or fluorenyl group; R**(10) is a C1-20 alkyl group, aryl group, alkyl aryl group or arylalkyl group; R**(11) is tetraphenylporphyrin

or phthalocyanine; m is a valency of M**(3) and M**(4) and is an integer of 1 to 7; n is an integer of 2 to 8; k is an ion value number of [L**(1)-R**(7)] and [L**(2)], and n is an integer of 1 to 7; and p is an integer of at least 1; and q is specified by the formula q=(p x k)/(n-m);

or said compound (b) being selected from the group consisting of tris(pentafluorophenyl)boron, tris(3,5-di(trifluoromethyl)phenyl) boron and triphenylboron;

(c) triisobutylaluminium."

III. In the interlocutory decision announced at the end of the oral proceedings, the Main Request was refused, because the subject-matter of Claim 1 was found to lack novelty over each of Examples 4 and 11 of document D1. Moreover, each of Auxiliary Requests 1 to 7 was held not to comply with the requirements of Article 123(2) EPC, because each Claim 1 contained a disclaimer not being in line with the ruling in the Decisions of the Enlarged Board of Appeal G 1/03 and G 2/03 (in both cases: points 2.6.5 and 3 of the reasons).

(1) By contrast, the subject-matter of the sole claim of amended Auxiliary Request 8, (section II (2), above, "Annexes 9.1 and 9.2" to the above decision) was, according to Nos. 4.1 to 4.3 of the reasons for the decision, based on the deletion of part of the definitions of compounds (a) and (b) initially contained in the application and a combination of these limited components with the selection of compound (c) from two preferred compounds. The Opposition Division held that these limitations did not amount to forming a new invention in comparison with the subject-matter as originally claimed, and that, therefore, the require ments of Article 123(2) EPC were met. Nor did the Opposition Division see any reasons for raising an objection under Article 84 EPC.

(2) Document D3, EP-A-0 277 004, was considered as being the closest piece of prior art, because it taught all features of Claim 1 except for the use of compound (c), ie tri-isobutyl aluminium (TIBA).

Neither D4 nor D7 mentioned or suggested, according to the decision, that TIBA was the preferred trialkyl aluminium scavenger for removing traces of oxygen or moisture from the polymerisation mixture, or related to the problem of increasing the activity of a catalyst comprising compounds as used in D3, corresponding to (a) and (b) of Claim 1 according to Auxiliary Request 8.

(3) A comparison between [Example 16], according to the claimed subject-matter, and [Example 17], being outside the claimed subject-matter, showed, according to the decision under appeal, that the use of TIBA as component (c) of the catalyst system led to an unexpected improvement of the catalyst activity.

Consequently, the Opposition Division acknowledged that the subject-matter of Claim 1 of Auxiliary Request 8 was based on an inventive step.

(4) According to the minutes of the oral proceedings, the Patent Proprietor was given the opportunity, after the announcement that Auxiliary Request fulfilled the requirement of Article 56 EPC, to adapt the description to this request, and the description thus amended was then further discussed and modified.

(5) Finally, the Opposition Division decided that "Account being taken of the amendments made by the patent proprietor during the opposition proceedings, the patent and the invention to which it relates are found to meet the requirements of the Convention." The reasons for this interlocutory decision were issued in writing on 18 September 2006.

IV. On 17 November 2006, an unsigned Notice of Appeal was received from Opponent O-01. A signed version thereof was, however, received from this party, referred to herein below as Appellant/O-01, on 10 January 2007, ie within the time limit set in a Communication dated 22 November 2006. Appellant/O-01 requested that the patent in suit be revoked in its entirety.

(1) In its Statement of Grounds of Appeal (SGA) received on 24 January 2007, Appellant/O-01 raised objections (i) of lack of inventive step (Article 56 EPC 1973) on the basis of D3 (as the closest piece of prior art) and D7 and (ii) under Article 123(2) EPC 1973 with regard (ii.a) to the restrictions in the denomination of "Cp" (methylcyclopentadienyl allegedly missing from the list of possible compounds) and of R**(1) to R**(4) (where "halogen" and "Lewis base" were asserted to be missing from the list of possible compounds) in component (a) and (ii.b) to the additional definition of "n" being an "integer of 1 to 7" (apparently meaning the definition of component (b)). This latter amendment would, moreover, contradict Article 83 EPC 1973.

(2) Document D3 would disclose all features of the operative claim except for feature (c). Thus, the definitions of components (a) and (b), respectively, in the patent in suit would most largely correspond to the definitions of the corresponding catalyst components in Claim 1 of D3. Moreover, the known catalysts would also serve the polymerisation of alpha-olefins, and, although there was no explicit reference to a third catalyst component, D3 (when talking of "a catalyst prepared by combining at least two components") would nevertheless give the hint, that a third component could be useful. Furthermore, D3 would explain that the activity of the catalyst could be impaired by oxygen and moisture.

(3) In the Appellant's opinion, D7 taught, that the catalyst activity could considerably be improved by adding aluminium alkyl compounds. Thus, D7 referred to a number of catalyst components (c) not being n-alkyl aluminium compounds, and it referred explicitly to TIBA. Moreover, there were hints that branched alkylaluminium compounds and, in particular, trialkylaluminium were particularly preferred. TIBA was exemplary for this, and it was used in most of the examples of D7. Comparative Example 3 of D7 demonstrated, according to the Appellant, in comparison with Example 1 of the document, that the addition of triethylaluminium (TEAL) resulted in significantly lower polymer yields than the addition of TIBA. Therefore, it was deemed obvious by the Appellant to improve the yield achieved in D3 by adding TIBA in accordance with the teaching of D7.

V. On 28 November 2006, the Patent Proprietor also filed an appeal requesting that the patent in suit be maintained as granted. This appeal was, however, withdrawn at oral proceedings on 28 August 2009. Therefore, the Patent Proprietor will be referred to herein below as "Respondent/P".

(1) In its then SGA received on 8 January 2007, the Respondent/P dealt with the question of whether the appeal of Appellant/O-01 would be deemed to have been filed or not, and with regard to its own appeal it stated that "We will therefore file detailed requests and grounds therefor as soon as we know the arguments upon which the appeal is based.".

(2) Moreover, it requested, even if the appeal of Appellant/O-01 was deemed not to have been filed, "to reintroduce some specific passages of the description, which were deleted during oral proceedings on September 18, 2006" and submitted, to this end, an amended version of pages 3, 6 and 7 of the specification. This new version was to replace the previous version as referred to in section III (4), above. In support of this request, Rule 139 EPC was invoked in a further letter dated 11 August 2009 (section IX, below).

VI. In its rejoinder dated 23 May 2007 to the appeal of Appellant/O-01, Respondent/P requested that the patent be maintained with a new claim filed therewith on the basis of Auxiliary Request 8 (section II (2), above), in which solely the definition of component (b) had further been amended to read as follows:

"(b) is a compound of formulas (VIII) or (IX)

|([L**(l)-R7]**(k+)p([M**(3)Z**(| (VIII) [sic] |

|1)Z**(2)....Z**(n](n-m)-)q | |

| | |

| (IX) |

| | |

| | |

wherein L**(2) is M**(5), R**(8)R**(9)M**(6), R**(10)3C or R**(11)M**(6); L**(1) is a Lewis base; M**(3) and M**(4) are independently an element selected from the groups IIIA, IVA and VA of the Periodic Table; M**(5) and M**(6) are independently an element selected from the groups IIIB, IVB, VB, VIB, VIIB, VIII, IA, IB, IIA, IIB and VIIA of the Periodic Table; Z**(1) to Z**(n) are independently a hydrogen atom, dialkylamino group, C1-20 alkoxy group, C6-20 aryl oxy group, C1-20 alkyl group, C6-20 aryl group, alkylaryl group or arylalkyl group, C1-20 halogenated hydrocarbon group, C1-20 acyl oxy group, organometalloid group or halogen atom; two or more of Z**(1) to Z**(n) may form a ring; R**(7) is C1-20 alkyl group, C6-20 aryl group, alkyl aryl group or arylalkyl group; R**(8) and R**(9) are independently a cyclo pentadienyl group, substituted cyclopentadienyl group, indenyl group or fluorenyl group; R**(10) is a C1-20 alkyl group, aryl group, alkyl aryl group or arylalkyl group; R**(11) is tetraphenylporphyrin

or phthalocyanine; m is a valency of M**(3) and M**(4) and is an integer of 1 to 7; n is an integer of 2 to 8; k is an ion value number of [L**(1)-R**(7)] and [L**(2)], and is an integer of 1 to 7; and p is an integer of at least 1; and q is specified by the formula q=(p x k)/(n-m);

or said compound (b) being selected from the group consisting of tris(pentafluorophenyl)boron, tris(3,5-di(trifluoromethyl)phenyl) boron and triphenylboron;".

Furthermore Respondent/P disputed the arguments in the SGA of Appellant/O-01 (sections IV (1) to IV (3), above) and requested that the patent in suit be maintained on the basis of the above new version of the claim, wherein "an obvious error has been corrected".

VII. In an annex to summons to oral proceedings, sent out on 11 May 2009, the parties were informed by the Board about the issues presumably to be discussed at the oral proceedings, including the admissibility of the appeals.

VIII. In letters dated 6 July and 17 July 2009, respectively, Appellant/O-01 and Respondent/O-02 informed the Board that they would neither attend, nor be represented, respectively, at the oral proceedings.

IX. In the further letter dated 11 August 2009 (already mentioned in section V (2), above), Respondent/P repeated its request that the patent in suit be maintained on the basis of the claim in its version of 23 May 2007 (section VI, above) or, in case the Board would not allow the new request ("... should intend to revoke the patent following the request of Appellant I", ie Appellant/O-01), Respondent/P requested that the case be remitted to the Opposition Division for further prosecution of the case on the basis of Auxiliary Requests 9 and 10, as annexed to the decision under appeal (Annexes 10/1 to 11/2).

X. On 28 August 2009, oral proceedings were held. At the outset of the hearing, the Board established that the parties had duly been summoned and announced that the proceedings were continued in the absence of Appellant/?O-01 and of Respondent/O-02, who had announced this (section VIII, above; Rule 115(2) EPC).

(1) Then the Board informed the attending Respondent/P about the reservations which the Board had with regard to the Respondent's appeal (Articles 107 and 108 EPC) and its request for amendment of pages 3, 6 and 7 of the specification (section V (2), above) under Rules 80 and 139 EPC).

(2) In view of these reservations, the Respondent/P withdrew its appeal and its above request for replacement of the previous version of pages 3, 6 and 7 (cf. sections V and III (4)/ V (2), above, respectively).

(3) However, a question had arisen with regard to page 8 of the version of the amended specification as annexed to the decision under appeal, because it contained, as replacement for the definitions on [page 8, lines 23 to 33], amended explanations in handwriting which extended to the right margin of the sheet and some of which were crippled in the official (electronic) file as available to the Board. The Respondent was therefore asked to verify that the text written by hand, but reproduced incorrectly (starting at line 22 after "... R**(11)M**(6)") was to read:

", and wherein L**(1), R**(7), M**(3), M**(4), Z**(1), Z**(2) to Z**(n), M**(5), M**(6), R**(8), R**(9), R**(10), R**(11), n, m and q are each defined as in claim 1."

(4) As a confirmation for this verified text, the Respondent submitted a new copy of page 8, corrected accordingly.

(5) Then the Board indicated to the Respondent/P that it saw neither a problem in respect of the suggested correction of the sole claim (as identified in section VI, above), nor a reason for raising an objection of lack of inventive step.

(6) Since the Respondent did not intend to give further comments, the Chairman closed the debate and interrupted the oral proceedings for the final deliberation of the Board.

XI. At this moment, the status of the requests was as follows:

Appellant/O-01 had requested, according to its submission in its Statement of Grounds of Appeal, dated 24 January 2007 and received on the same day, that the decision under appeal be set aside and the patent in suit be revoked in its entirety.

Respondent/P requested that the appeal be dismissed subject to the correction of the claim according to the version filed with the letter dated 23 May 2007. In the alternative, it requested that the case be remitted to the Opposition Division, if the Board intended to revoke the patent in suit following the request of Appellant/O-01, or that the patent be maintained on the basis of Auxiliary Requests 9 or 10 as annexed to the decision under appeal.

Respondent/O-02 had neither commented in substance on the content of the file, nor submitted any requests during these appeal proceedings.