T 0341/92 (Basic lead salts) 30-08-1994
Main request: inadmissible extension (yes) - new objection in oral proceedings in patent proprietor's absence
Subsidiary request: inventive step (yes)
I. European patent No. 184 128 comprising 11 claims was granted on the basis of European patent application No. 85 115 046.6 filed on 27 November 1985. The notice of grant was published in Patent Bulletin 88/22 on 1 June 1988. The only independent claim read as follows:
"A process for the production of lead(II) fatty acid salts by reaction of lead(II) oxide with a melt of the lead-salts-forming fatty acids, especially during production of stabiliser mixtures for halogen-containing polymers, particularly PVC, characterised in that dibasic lead salts of the formula 2PbO.Pb (fatty acid residue)2 are prepared in a melt of the neutral lead fatty acid salts containing organic hydroxyl compounds with addition of lead(II) oxide."
II. Notice of opposition to the grant of the patent was filed by respondents (i) on 28 February 1989 and respondents (II) on 1 March 1989, requesting that the patent be revoked on the ground of lack of novelty and inventive step. ...
III. By the decision announced on 24 September 1991 and followed on 10 February 1992 by a written statement of the reasons on which it was based, the patent was revoked.
The decision was taken on claims 1 to 9 filed on 26 August 1989. Claim 1 essentially corresponded to claim 1 of the contested patent, but was limited by the exclusion of certain hydroxyl compounds, namely fatty alcohols, glycerol-12-hydroxystearate and triethanolamine distearate.
The decision stated that, although the subject-matter of amended claim 1 was new, it did not involve an inventive step. ...
IV. An appeal, accompanied by payment of the prescribed fee, was filed against this decision on 7 April 1992, and the statement setting out the grounds was filed on 27 May 1992.
Together with this statement of grounds, the appellants filed as the main request new claims 1 to 8, with claim 1 reading as follows:
"A process for the production of dibasic lead salts of the formula 2PbO.Pb (fatty acid residue)2 by reaction of lead(II) oxide with a melt of the lead-salts-forming fatty acids in the presence of organic stabiliser or lubricant components for PVC containing free hydroxyl groups during production of stabiliser mixtures for PVC, characterised in that partial esters of glycerol and/or pentaerythritol are used as lubricant components containing free hydroxyl groups."
At the same time they submitted new claims 1 to 7 as a subsidiary request. Claim 1 reads as follows:
"A process for the production of predetermined mixtures of neutral and dibasic lead salts of the formula 2PbO.Pb (fatty acid residue)2 by reaction of lead(II) oxide with a melt of lead-salts-forming fatty acids, in which
- neutral lead salt is initially formed by reaction in the melt,
- partial ester of glycerol and/or of pentaerythritol and more lead(II) oxide is added to the melt, and
- the reaction is continued until the lead(II) oxide has been converted into basic lead salt."
They requested that the contested decision be set aside and the patent be maintained on the basis of claims 1 to 8 (main request) or 1 to 7 (subsidiary request).
V. In support of their view that the subject-matter of these claims involved an inventive step, the appellants argued that ...
VI. Respondents (i) dispute this view. ...
VII. On 30 August 1994 oral proceedings took place at the request of both the appellants and respondents (i); the appellants and respondents (II) were not represented, having notified the board to that effect in advance.
During the oral proceedings respondents (i) commented in detail on the allowability of the main request. The board took up the issue of whether the subject-matter of claim 1 according to the main request infringed Article 123(3) EPC. Respondents (i) held that the deletion of the passage "in a melt of the neutral lead fatty acid salts" had extended the protection conferred. After the board had indicated that it did not consider the main request allowable, respondents (i) declared that they would not make any further comment on the subsidiary request.
VIII. Respondents I (opponents I) requested that the appeal be dismissed.
IX. At the end of the oral proceedings it was announced that the patent would be maintained with the claims according to the subsidiary request.
1. The appeal complies with the requirements of Articles 106 to 108 EPC and Rule 64; it is therefore admissible.
2. Main request
2.1 The main difference between claim 1 of the main request and the claim in the granted patent is that the feature in the patent claim, according to which the dibasic lead fatty acid salts are prepared in a melt of neutral lead fatty acid salts, is missing. Thus - contrary to the specific instruction in the claim of the granted patent - carrying out the process in a melt of neutral lead fatty acid salts is no longer an essential process parameter, but is now merely optional. Claim 1 as now worded thus extends the protection conferred by the granted patent, since embodiments not covered by the claim in the granted patent come within the scope of the amended claim.
2.2 The board therefore concludes that the subject-matter of claim 1 infringes Article 123(3) EPC and that the main request accordingly fails.
2.3 The question of the extension of the protection conferred by claim 1 according to the main request was brought up for the first time during the oral proceedings. The board does not consider itself prevented by reasons of procedural law from taking the fact that Article 123(3) EPC precludes the maintenance of the patent in this version as a basis for its decision on the main request in accordance with the outcome of the oral proceedings.
2.3.1 Under Article 113(1) EPC, a decision may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments. The Enlarged Board of Appeal has interpreted this provision concerning the right to be heard as meaning that a decision against a party which has been duly summoned but which fails to appear at oral proceedings may not be based on facts put forward for the first time during those oral proceedings (G 4/92, OJ EPO 1994, 149, Conclusion 1).
2.3.2 This is not the situation in the present case. The extension of the protection conferred, to which objection is made, arises solely from a comparison of the wording of the respective claims according to the granted patent and according to the main request now at issue, and therefore not from facts which were only introduced into the case during oral proceedings.
2.3.3 In the above-mentioned decision, the Enlarged Board of Appeal viewed the possibility of holding oral proceedings in a party's absence, as provided for in the EPC, in relation to the need for proper administration of justice, in the interests of which no party should be able to delay the issue of a decision by failing to appear at the oral proceedings (loc. cit., point 4 of the reasons). This can only mean that parties to the proceedings must expect that, on the basis of the established and plainly relevant facts, any decision taken may go against them. It can further be inferred from this that a decision may be based on a ground discussed for the first time during oral proceedings which would prevent the patent being maintained as amended, at least if the stage reached in the case was such that the absent - albeit duly summoned - patent proprietor could have expected the question to be discussed and was aware from the proceedings to date of the actual bases on which it would be judged.
2.3.4 This requirement is fulfilled in the present case. According to established board practice, prior to examination of the patentability requirements laid down in Articles 52 to 57 EPC, amended claims are checked by the board of its own motion during the opposition appeal proceedings for formal admissibility and, in particular, the possibility of an infringement of Article 123(2) and (3) EPC. There is an obvious need to check for this latter possibility if the patent proprietor deletes a feature in an independent claim. In the case at issue, this check had not been made prior to the oral proceedings. It was therefore to be expected that a comparison of the amended claims with those of the granted patent for the purposes of Article 123(3) EPC would form part of the discussions at the oral proceedings, and the patent proprietors had reason and the opportunity to prepare themselves for this eventuality. If they nevertheless preferred not to attend the oral proceedings - which they too had requested - they failed to take up an opportunity to comment on this ground for the present decision.
3. Subsidiary request
3.1 There are no objections under Article 123(2) and (3) to the claims set out in the above request, which are limited in comparison with the text of the granted patent. ...
4. It therefore remains to examine whether the subject-matter of the patent involves an inventive step. ...
4.10 In view of all the foregoing, the board concludes that the subject-matter according to claim 1 does involve an inventive step.
4.11 Independent claims 2 to 7 relate to special embodiments of the method set out in claim 1 and are supported by its patentability.
For these reasons it is decided that:
1. The decision under appeal is set aside.
2. The case is remitted to first instance with the order that the patent be maintained with the claims according to the subsidiary request, received on 27 May 1992, and with a description which still needs to be amended accordingly.