T 0288/84 (Activated support) of 7.2.1986

Summary of Facts and Submissions

I. In respect of European patent application No. 78 200 273.7 which was filed on 30 October 1978 claiming the priority of a Netherlands application dated 1 November 1977 European patent No. 1 862 was granted on 7 July 1982 on the basis of ten claims, the first and seventh of which read as follows:

"1. Catalytic titanium halide component on a magnesium halide support, which can be used for the polymerisation of 1-alkenes or for the co-polymerisation of 1-alkenes with each other or with ethylene, characterised in that the amount of water in the magnesium halide is less than 0.2 per cent by weight and the amount of magnesium oxide less than 0.1 mgeq titratable base per gram of magnesium halide, and that the magnesium halide has been prepared by heating a magnesium halide, containing water and/or magnesium oxide, in a gaseous flow of carbon halide vapour and/or mixture of carbon monoxide and a halogen.

7. Process for the polymerisation of 1-alkenes or for the co- polymerisation of 1-alkenes with each other or with ethylene with the use of a catalyst system that contains a titanium halide component on a magnesium halide support and an organoaluminium component containing a complex of an organic aluminium compound with an ester of an organic acid containing oxygen, the process being characterised in that a titanium halide component according to any one of the claims 1-6 is used."

II. On 18 March 1983 the opponent filed a notice of opposition against the grant of the patent, claiming on the basis of the results of its own experiments that the subject-matter of the contested patent was not sufficiently disclosed or reproducible, and citing document (1) US-A-4 298 718 (published subsequently). In its defence the patent proprietor referred to document (2) NL-A-7 208 558 already mentioned in column 1, line 15, of the contested patent specification.

III. By decision of 10 October 1984 the Opposition Division revoked the patent explaining that according to Claim 1 and column 3, lines 54 to 56 of the contested patent description the titanium halide could be applied to the magnesium halide support in any known manner. Although a person skilled in the art could infer from the cited state of the art (2) that activated magnesium halide was to be used as the support, experiments conducted by the opponent had shown that simple mixing of a suspension of activated magnesium chloride with a solution of TiCl4 and customary processing did not yield the desired results. The opponent's experiments further proved that not even the fineness of the support was an adequate criterion for guaranteeing reproducibility. Since the patent proprietor neither refuted the opponent's experimental results nor restricted the claims, as had been suggested, within the meaning of column 3, line 57, of the description (grinding together of titanium halide and magnesium halide), the patent had to be revoked on the grounds that it lacked the reproducibility claimed.

IV. The appellant (patent proprietor) appealed against the decision of the Opposition Division on 8 December 1984, at the same time paying the prescribed fee; the statement of grounds of appeal, the tenor of which is reproduced below, was sent by telex on 11 February 1985 and confirmed by letter on 14 February 1985: Document (2) teaches not only the need for an activated magnesium halide support but also how activation can be brought about and how activated and non-activated magnesium halide can be distinguished. The respondent's (opponent's) experiments merely show that a non-activated magnesium halide support leads to poor results. As it stands the disclosure is therefore sufficient; however, the appellant is prepared to clarify Claim 1, should the Board consider this to be necessary.

V. The respondent countered with the argument that the use of activated magnesium halide was neither mentioned in the original documents nor did it emerge automatically from an expert interpretation of the contested specification. It therefore requested that the appeal be rejected.

VI. The Board informed the parties that insertion of the word "activated" before "magnesium halide" was formally admissible and called for in the pre-characterising portion not only of Claim 1 but also of Claim 7: whether the respondent's experiments were carried out with activated or non-activated magnesium halide might be a decisive factor in an assessment of the adequacy of the disclosure.

VII. The appellant reacted to the foregoing by pointing out on 14 October 1985 that the notice of opposition dated 17 March 1983 had made clear that the respondent's experiments were carried out with non-activated magnesium halide and requested that the contested decision be set aside and the patent be maintained "in its present version".

VIII. The respondent thereupon requested a decision based on the content of the file.

IX. In a communication dated 19 December 1985 fixing the time limit under Rule 58(4) EPC, the Board informed the parties of the way in which it interpreted the appellant's request and in which text it intended to maintain the patent. The parties did not contest this text within the one-month time limit set.

Reasons for the Decision

1. The appeal complies with Articles 106 to 108 and Rule 64 EPC and is therefore admissible.

2. When filing the notice of opposition the respondent had, in addition to complaining that the invention was insufficiently disclosed, summarily asserted that the subject-matter of the contested patent did not comply with the requirements for a patentable invention "within the meaning of Article 100(a) and (b) EPC", but at no stage in the opposition or appeal proceedings did it substantiate its claim with regard to Article 100(a) (i.e. indirectly with regard to Articles 52 to 57). Under these circumstances no objection can be raised to the fact that in its decision the previous instance did not go into the question of whether the requirements of Articles 52 to 57 had been met. Nor is the Board aware from its own technical knowledge of any prior art barring the patentability of the contested patent in this respect. All that needs to be examined, therefore, is whether within the meaning of Article 100(b) the contested patent discloses the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (Article 83 EPC).

3. The parties had not disputed that the polymerisation process described in Claim 7 could be reproduced with the results indicated only if the magnesium halide support for the titanium halide component of the catalyst protected by Claim 1 was activated magnesium halide. It therefore needs to be established whether this feature, although not expressly mentioned, is disclosed in the original documents and still contained in the contested patent specification as granted.

4. The introductory part of the description of both original documents and patent specification explains that the invention concerns a titanium halide component on a magnesium halide support as well as the use of this catalyst system in a polymerisation process. It goes on to say that a catalyst of this nature, consisting of titanium halide on a water-free magnesium halide and of an organoaluminium component (defined more precisely by its method of production), and its use in such a process are already known from (2). The disadvantage of such a catalyst system lies in the insufficient stereospecificity of the polymerisation process. It is furthermore explained that with the aid of a modified organoaluminium component according to document (3) NL-A-7 509 735 (that likewise has to be included in the published prior art) the stereospecificity can be improved somewhat but still needs further improvement (column 1, lines 44 to 46).

5. Although it is not immediately evident from the foregoing that activated magnesium halide is used according to the prior art cited, this becomes clear from a reading of the latter:

5.1 The support for the titanium halide component defined in paragraph (b) (page 27, line 15 et seq.) is already characterised in Claim 1 of (2) by its specific surface and its X-ray spectrum in which a line characteristic of normal, non-activated magnesium halide is said to be dispersed (page 27, lines 21 to 23). The description in (2) is clearer still and also extremely specific on this point: magnesium halide "in previously activated form", first mentioned on page 6, lines 13 and 14, subsequently (lines 16 to 20) is again characterised as above by specific surface and X-ray spectrum. On page 7, lines 9 to 14, magnesium halide "in active form" is then explicitly defined in the manner indicated, following which (page 7, line 15, to page 8, line 7) various methods are described by means of which the magnesium halide can be converted into "active form".

5.2 Document (3) takes (2) as the prior art and in its assessment of the latter for the first time mentions activated magnesium halide on page 2, lines 8 and 9. Since (3) is primarily concerned with the modification of the organoaluminium component of the catalyst system it is only natural that the magnesium halide support for the titanium halide component is not described in as much detail as in (2); but even here particularly favourable results regarding the activity and stereospecificity of the catalyst are claimed when a specially activated magnesium halide support characterised as in (2) by specific surface and X-ray spectrum (page 4, lines 11 to 15) is used.

6. The subject-matter of the contested patent is linked with this state of the art in two places in particular:

6.1 The invention to which the contested patent relates is described in column 1, lines 5 to 12, of the specification which continues with an assessment of (2): "Such a titanium halide component and such a process ...." (column 1, lines 13 and 14). From this it follows that the support taken as a basis for the invention according to the contested patent and relying on (2) and (3) is not just any magnesium halide but the (water-free and activated) magnesium halide according to (2), which is then processed according to the invention.

6.2 Likewise the contested patent is presented in terms of problem and solution against the background of the prior art represented by (2) and (3) which is linked with the improvement according to the invention by the statement that the stereospecificity "of such a catalyst system - i.e. that referred to in (3) - can be increased by using a magnesium halide that is not only free from water, as in (2) and (3), but also - at least substantially - free from magnesium oxide and obtained in a particular way (column 1, lines 47 to 57); in other words, to the features of magnesium halide known from (2) and (3) - free from water and activated - the contested patent adds two others: absence of magnesium oxide and method of production.

6.3 From this it follows that the skilled person to whom the patent specification is addressed needed to understand the prior art referred to therein and represented by (2) and (3), and also its advantageous further development according to the contested patent, as meaning that the magnesium halide characterised and used in the manner claimed had moreover to be "activated" as well within the meaning of (2) and (3).

6.4 This interpretation is further reinforced by the fact that in all seven claims in the contested patent specification the activation process preceding the actual invention is in fact described, even if not mentioned as such by name: according to (2), page 7, lines 32 to 35, the activation is preferably carried out by grinding the magnesium halide, in particular in a ball mill; this is explained in detail in examples I to XII, XIV to XXV, LVI to LXI, LXXII and LXXIII in (2) in the form of grinding together of magnesium halide and titanium halide or a complex containing such. Said grinding is also carried out according to all nine examples in (3), and a similar grinding process is described in all seven examples in the contested specification: see column 6, lines 22 to 26; column 7, lines 31 to 36 and 56 to 58; column 9, lines 18 to 21, 34 to 37 and 51 to 54; column 10, lines 25 and 26.

6.5 If an invention relates to the improvement of prior art originally cited in the description of the invention, a feature (here: "activated" support) described in broad terms in the cited document but not mentioned expressly in the invention is sufficiently disclosed if it is realised in the examples of the invention in the form of an embodiment also mentioned in the reference document (here: activation by grinding).

7. If, therefore, from the point of view of the skilled person reading the documents, the use of activated magnesium halide is clearly disclosed both in the original documents and in the contested specification, the word "activated" may, and indeed should, be added in the appropriate places in the characterising portion of Claims 1 and 7; an originally disclosed feature restricting the wording of a claim may still be added to the claims during opposition and appeal proceedings.

8. The objections raised by the respondent under Article 100(b) EPC accordingly cannot be sustained against Claims 1 and 7 in the version now requested. The same applies to the dependent Sub- claims 2 to 6 and 8 to 10.

ORDER

For these reasons, it is decided that:

1. The contested decision is set aside.

2. The case is remitted to the previous instance with the order that the European patent be maintained subject to an amendment in the form of the addition in the German text of Claims 1 and 7, column 10, line 41, and column 11, line 18, respectively, of the word "aktivierten" (activated) before "Magnesiumhalogenid" (magnesium halide).