T 1103/05 17-10-2007

1. The appeal is admissible.

Main request

2. Novelty

2.1 In its decision, the Opposition Division had considered that Claim 1 as granted lacked novelty in view of the disclosure of documents D2 and D3. While the Appellant had contested the findings of the Opposition Division in that respect, the Respondent had maintained the view that D2 and D3 were novelty destroying documents for the subject-matter of granted Claim 1.

2.2 Document D2 relates to an olefin polymerization solid catalyst obtainable by prepolymerizing an olefin in a suspension comprising:

[A] a component obtainable by bringing a particulate carrier, an organoaluminum compound [A-a] and water into contact with one another,

[B] a transition metal compound containing a ligand having a cycloalkadienyl skeleton

and [C] an organoaluminum compound (Claims 1 and 2).

2.3 According to D2, the particulate carrier includes particulate inorganic or organic carriers having an average particle diameter of usually 1-300 mym. The particulate inorganic carrier used includes preferably oxides, such as SiO2, Al2O3, MgO, ZrO2, TiO2 or mixtures thereof and the particulate organic carrier used includes particulate organic polymers, such as polystyrene or particulate polymers of olefins (e.g. polyethylene, polypropylene, poly-1-butene and poly-4-methyl-1-pentene) (page 3, lines 45 to 52). The organoaluminum compounds [A-a] used in the preparation of component [A] comprise compounds such as trialkylaluminum compounds, dialkylaluminum halides, dialkylaluminum hydrides, dialkylaluminum alkoxides, dialkylaluminum aryloxides and isoproprenylaluminum compounds (page 3, line 53 to page 4, line 6).

2.4 According to D2, the transition metal compound [B] is represented by the formula MLx wherein M is a transition metal, L is a ligand coordinating to the transition metal, at least one of L is a ligand having a cycloalkadienyl skeleton, and when at least two or more ligands having a cycloalkadienyl skeleton are contained, at least two ligands having a cycloalkadienyl skeleton may be linked together via alkylene, substituted alkylene, silylene or substituted silylene, L other than the ligand having a cycloalkadienyl skeleton is hydrocarbon group of 1-12 carbon atoms, alkoxy of 1-12 carbon atoms, aryloxy, silyloxy, halogen or hydrogen, and x is a valence of the transition metal. M which is a transition metal includes zirconium, titanium, hafnium, chromium or vanadium by preference (page 4, lines 9 to 17).

2.5 As disclosed in D2 the organoaluminum compounds [C] may be compounds having the formula R**(6)nAlX3-n wherein R**(6) is hydrocarbon of 1-12 carbon atoms, X is halogen and n is 1-3, alkylaluminum sesquihalides, alkylaluminum hydrides, or compounds represented by the formula

R**(6)nAlY3-n wherein R**(6) is as defined previously, Y is

-OR**(7), -OSiR**(8)3, -OAlR**(9)2, -NR**(10)2, -SiR**(11)3 or

FORMULA/TABLE/GRAPHIC

n is 1-2, R**(7), R**(8), R**(9) and R**(13) are each methyl, ethyl, isopropyl, isobutyl, cyclohexyl or phenyl, R**(10) is hydrogen, methyl, ethyl, isopropyl, phenyl or trimethylsilyl, R**(11) and R**(12) are each methyl or ethyl (page 5, line 43 to page 6, line 11).

2.6 More specifically, D2 discloses in its Examples 1 to 3, the preparation of a catalyst according to Claims 1 and 2 thereof in which the particulate carrier used in the preparation of component [A] is silica, the component [C] is triisobutylaluminum, and the transition metal catalyst is a zirconium compound with cyclopentadienyl ligands (bis(methylcyclopentadienyl) zirconium dichloride in Ex.1, bis(methylcyclopentadienyl) zirconium methoxy monochloride in Ex.2, and ethylenebis(indenyl)zirconium dichloride in Ex.3).

2.7 Document D3 deals with an olefin polymerization solid catalyst obtainable by prepolymerizing at least one olefin in the presence of:

[A-2] a solid catalyst component comprising (a-1) a particulate carrier which is (i) composed of an oxide of at least one element belonging to Group II, III or IV of the Periodic Table, (ii) contains less than 1.0% by weight of water and (iii) comprises at least 1.0% by weight of surface hydroxyl groups, and supported on the particulate carrier (a-1);

(a-2) an organoaluminum oxy compound

[B] a catalyst component which is a compound of at least one transition metal belonging to Group IVB of the Periodic Table containing a ligand having a cyclopentadienyl skeleton; and, optionally,

[C-1] a catalyst component which is an organoaluminum compound.

The catalyst might further comprise a component [C-2] which is an organoaluminum compound (Claims 7 and 10).

2.8 According to D3, the particulate carrier (a-1) includes particulate inorganic compounds comprising an oxide of at least one element selected from among those belonging to the groups II, III and IV of the Periodic Table, and is preferably selected from porous oxides such as SiO2, Al2O3, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ThO2 or mixtures of porous oxides (page 4, lines 52 to 56).

2.9 The organoaluminum compounds [C-1] and [C-2] are compounds represented by the formula R**(5)nAlX3-n wherein R**(5) is hydrocarbon of 1-12 carbon atoms, X is halogen or hydrogen and n is 1-3 (e.g. trialkylaluminum,

dialkylaluminum halides, alkylaluminum dihalides, and alkylaluminum hydrides), alkylaluminum sesquihalides or compounds represented by the formula R**(5)nAlY3-n wherein R**(5)is as defined previously, Y is -OR**(6), -OSiR**(7)3, -OAlR**(8)2, -NR**(9)2, -SiR**(10)3 or N(R**(11))AlR**(12)2, n is 1-2, R**(6), R**(7), R**(8), and R**(12) are each methyl, ethyl, isopropyl, isobutyl, cyclohexyl or phenyl, R**(9) is hydrogen, methyl, ethyl, isopropyl, phenyl or trimethylsilyl, R**(10) and R**(11) are each methyl or ethyl (page 11, lines 30 to 54).

2.10 More precisely, D3 discloses in its Examples 1 to 9, 11 to 31, catalyst compositions comprising a silica as particulate carrier, a zirconium compound having cyclopentadienyl ligands as transition metal compound, and triisobutylaluminum either as component C-1 (Examples 1 to 3, 9, 11 to 12, 14 to 15, 30) or as component C-1 and component C-2 (Examples 4 to 8, 13, 16 to 29, 31 to 33). In the catalyst composition according to Example 10, neither a component C1 nor a component C-2 is present.

2.11 In this connection the Board however observes that Claim 1 of the patent in suit requires explicitly that the solid catalyst composition must comprise

(i) an organoaluminum oxy-compound (a),

(ii) a group IVB transition metal compound containing a ligand or ligands having a cyclopentadienyl structure (b),

(iii) a hydrogenated organoaluminum compound (c),

and

(iv) a particulate silica (d).

2.12 These compositional features (i),(ii), (iii) and (iv) are further associated in Claim 1 with process features (v) according to which the catalyst is obtainable by bringing (d) into contact with (a) and then bringing the resulting product into contact with (b) and (c), in either order.

2.13 Independently of the fact that process features can only contribute to the novelty of a product claim insofar as they give rise to "other" products (cf. decision T 205/83, (OJ EPO 1985, 363; Reasons 3.2.1), the Board observes that in document D2 an oxy organoaluminum compound is formed in situ by reaction of the organoaluminum compound [A-a] with water in presence of the particulate support, and hence inevitably brought into contact with this particulate carrier before being mixed with the other components of the catalyst (i.e. transition metal compound and organoaluminum compounds). The Board further observes that in document D3 the component [A-2] is composed of an oxy organoaluminum compound supported on a particulate carrier (i.e. brought into contact with the particulate carrier) and mixed with the further components of the catalyst (i.e. the group IV transition metal catalyst and the components C-1 and/or C-2 when present). It thus follows that process feature (v) according to granted Claim 1 does not constitute a distinguishing feature over documents D2 and D3.

2.14 Consequently, it remains to be decided whether the combination of compositional features (i), (ii), (iii) and (iv) set out in paragraph 2.11 above provides a distinction over D3 and D2.

2.15 According to the decision T 355/99 of 30 July 2002 (not published in OJ EPO),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).

2.16 Thus, the question boils down as to whether there is in D2 and D3 a clear and unmistakable teaching of the combination of features mentioned above in paragraph 2.11.

2.17 In this connection, the Board observes that, while the reaction of the organoaluminum compound [A-a] with water according to document D2 would indisputably result in the formation of an oxy organoaluminum compound falling under the definition of component [A] according to Claim 1 of the patent in suit, it still remains that the particulate carrier in D2 can be chosen among a list of inorganic and organic particulate carriers including silica as one of its members, that the transition metal [B] in D2 containing a ligand having a cycloalkadienyl skeleton can be chosen among a list of transition metal compounds including Group IV B transition metals, and that the organoaluminum compound [C] of D2 can be chosen among a list including hydrogenated organoaluminum compounds as members (cf. paragraphs 2.3, 2.4 and 2.5 above).

2.18 Thus, in order to come to a catalyst composition falling under the scope of Claim 1 as granted, it is necessary to select silica from a list of particulate carriers, to select Group IVB transition metal catalyst among the transition metal compounds, and to select hydrogenated organoaluminum among the organoaluminum compounds.

2.19 The Board can only state that there is no explicit disclosure of such combination in D2, either in the general part of the description or in the examples.

2.20 Nor could this combination be considered as implicitly disclosed in D2 in view of the Examples of D2 and the teaching on page 5, line 58 of D2 according to which alkyl aluminum hydrides could be used as organoaluminum compound [C].

2.20.1 This is principally because considerations as to whether the replacement of triisobutyl aluminum by a hydrogenated organoaluminum compound in the catalyst compositions disclosed in Examples 1 to 3 of D2 could have been suggested to the skilled person by the passage on page 5 would amount, in the Board's view, to inventive step considerations which must be avoided when assessing novelty (cf. decision T 572/88 of 27 February 1991; not published in OJ EPO).

2.20.2 Even if, however, a modification of the catalyst composition of Examples 1 to 3 would have been contemplated by the person skilled in the art, he would have been confronted with several possibilities of modifications such as the ratio of the different components, modification of the particulate carrier, modification of the transition metal compound such as done in Example 2 in respect to the composition of Example 1, or modification of the organoaluminum compound, so that it could not be ascertained that the skilled person would have inevitably replaced the triisobutylaluminum compound by a hydrogenated organoaluminum compound in the compositions of Examples 1 to 3 of D2.

2.20.3 In addition to these several possibilities of modifications, the skilled reader of D2 should furthermore have perceived from the outset that the contemplated modification would inevitably result in an equivalent catalyst composition to the one disclosed in the examples of D2. This is, however, in the present case highly questionable, since triisobutyl aluminum, in contrast to hydrogenated organoaluminum components belongs to preferred organoaluminum components in D2 (cf. page 6, lines 29 to 31).

2.21 Consequently, since there is in D2, either explicitly or implicitly, no clear and unmistakable teaching of the combination of features mentioned above in paragraph 2.11, the subject-matter of granted Claim 1 must be regarded as novel over D2 (Article 54(1)(2) EPC. The same conclusion evidently applies to the subject-matter of Claims 2 to 5.

2.22 Concerning document D3, while it is clear that the organoaluminum oxy compound [a-2], and the component [B] of the catalyst composition according to Claim 7 of D3 fall, respectively, under the definition of component (a) and (b) of the catalyst composition according to granted Claim 1, it still remains that the particulate carrier (a-1) in D3 can be chosen among a list of inorganic particulate carriers including silica as one of its member, and that the optional organoaluminum compounds [C1] and [C2] of the catalyst composition according to Claim 7 of D3 can be chosen, if used, among a list among a list including hydrogenated organoaluminum compounds as members (cf. paragraphs 2.8 and 2.9 above).

2.23 Thus, in order to come to a catalyst composition falling under the scope of Claim 1 as granted, it is necessary to select silica from a list of particulate carriers, to choose to use a component [C1] and/or [C2], and, if so, to further select hydrogenated organoaluminum among the organoaluminum compounds as components [C1] and/or [C2].

2.24 The Board can only state that there is no explicit disclosure of such combination either in the general part of the description or in the examples of D3.

2.25 Nor could the specific combination of features required by granted Claim 1 be considered as implicitly disclosed in D3 in view of the examples of D3 referred above in paragraph 2.10 and of the teaching at page 11, lines 30 to 33, and 48 of D3, according to which alkyl aluminum hydrides could be used as organoaluminum compounds [C1] and or [C2].

2.25.1 While it is true the catalyst compositions disclosed in the Examples 1 to 9, and 11 to 33 differ from the claimed catalyst compositions according to granted Claim 1 only in that triisobutylaluminum is used as organoaluminum compound (i.e. either as component [C1] in Examples 1-3, 9, 11, 12, 14, 15 and 30, or as components [C1] and [C2] in Examples 4 to 8, 13, 16-29, 31 and 33), this is firstly because the same considerations as made above in paragraphs 2.20.1 would equally apply to document D3 when assessing novelty of the subject-matter of Claim 1.

2.25.2 Even if, however, a modification of the catalyst composition of Examples 1 to 9, 11 to 33 would have been contemplated by the person skilled in the art, he would, as in the case of D2, have been confronted with several possibilities of modifications such as the ratio of the different components, modification of the carrier, modification of the transition metal compound, or modification of the organoaluminum compound [C1] and/or [C2] or no use of them as done in Example 10 of D3, so that it could not be ascertained that the skilled person would have inevitably replaced the triisobutylaluminum compound used in these Examples 1 to 9 and 11 to 33, by a hydrogenated organoaluminum compound, taking further into account that, as in the case of D2 (cf. paragraph 2.20.3), triisobutyl aluminum in contrast to hydrogenated organoaluminum components belongs to preferred organoaluminum components in D3 (cf. page 12, lines 10 to 12).

2.26 Consequently, the subject-matter of granted Claim 1 must be regarded as novel over D3 (Article 54(3)(4)) EPC. The same conclusion evidently applies to the subject-matter of granted Claims 2 to 5.

3. Remittal

3.1 As indicated above in Section IV, the Opposition Division rejected the main request for lack of novelty of granted Claims 1, 3 and 5, and as a consequence did not express its opinion regarding the ground of lack of inventive step of the subject-matter of granted Claim 1.

3.2 Having regard to the requests of both Parties for remittal to the first instance and in order not to deprive them of the possibility to be heard by two instances, the Board considers it appropriate to make use of its discretionary power under Article 111(1) EPC and to remit the case to the first instance for further prosecution.