Wednesday, 18 December 2013

T 59/08 - Just pipe down


 The unsurpassed K's law which has been kept by O

This is an opposition appeal.

The claims according to the  main and an auxiliary request were identical to the claims as granted.  Claim 1 contains the feature "said HMW fraction having a lower molecular weight limit of 3500".  

The application gave no method for determining the lower limit of the high molecular weight (HMW). The opponents objected that the invention was not disclosed in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.

The board found that the claim may give the skilled person a clarity problem, when deciding if a particular composition falls under the claim. However he is sufficiently enabled to work the invention.

Reasons for the Decision
1. The appeal is admissible.

2. The question to be answered when assessing sufficiency of disclosure is whether the invention as defined in the claims can be performed by a person skilled in the art throughout the whole area(s) claimed without undue burden, taking into account the information given in the patent in suit and using common general knowledge.

2.1 The invention of which the sufficiency of disclosure has to be judged is the object defined in present claim 1 by the combination of the following features:

(i) a multimodal polyethylene composition suitable for pipes,
the multimodal polyethylene having
(ii) a density of 0.930-0.965 g/cm**(3),
(iii)a MFR5 of 0.2-1.2 g/10 min,
(iv) a Mn of 8000-15000, a Mw of 180?330 x 10**(3) and a Mw/Mn of 20-35,
and comprising
(v) a low molecular weight (LMW) ethylene homopolymer fraction and a high molecular weight (HMW) ethylene copolymer fraction in a weight ratio of the LMW fraction to the HMW fraction of (35-55) : (65-45)
(vi) said HMW ethylene copolymer fraction having a lower molecular weight limit of 3500.

2.2 The contested decision nor the parties on appeal addressed the question whether the present patent specification disclosed a technical concept fit for generalisation and whether it made available to the skilled person, with his common general knowledge, compositions suitable for pipes meeting the combination of parameters defined in claim 1, as well as the pipes according to claim 12. The questions addressed were rather which meaning should be attributed to the feature "lower limit of the high molecular weight (HMW) ethylene copolymer fraction" and whether, in the absence of any mention in the patent with respect to the measurement methods for determining Mn, Mw and the lower limit of the high molecular weight (HMW) ethylene copolymer fraction, the skilled person would know which measurement method was to be employed.

2.3 Following the normal rule of claim construction according to which terms used in a claim should be given their ordinary meaning in the context of the claim in which they appear, the lower molecular weight limit of the HMW ethylene copolymer fraction defined in claim 1 designates the lowest molecular weight of any of the molecules of the HMW fraction. This view is supported by the statement provided in the specification on page 3, lines 9-12 and was not disputed any longer during the oral proceedings.

2.4 In the absence in the claim of any indication of a method for determining Mn, Mw and the lower limit of the high molecular weight (HMW) ethylene copolymer fraction, the claim has to be read as allowing any method of measurement, including any setting, that can be said to be standard in the art concerned; in other words, any ordinary method within the context of the present claim. In this respect, the parties do not dispute that different methods (for example GPC), including different settings, would be available to determine values for those parameters, nor that the choice of the measurement method for determining said parameters has an influence on the values obtained.

2.5 The notions of "true value" and closeness to that "true value" in relation to Mw and Mn parameters, to which the appellant referred, are however not only vague, but also not reflected by the information provided in the patent in suit. If a patent proprietor wishes to argue that a parameter range in a claim should be read in a special way or needs to be measured in a particular manner because several possibilities are available, then for that argument to be accepted it is necessary to limit the claim to this method of measurement by way of amendment, provided that this can be done meeting the requirements of Article 123(2) EPC. It is not enough to argue that the claim should be read in a particular way when the wording of the claim does not require this. For lack of information to that effect, it is not apparent that the skilled person would try to determine the "true value" of Mw and Mn, as it is at least equally credible that he would choose any standard method meeting his needs in the context of the technical circumstances of the case, i.e. also taking into account the convenience and reproducibility of that method.

2.6 Therefore, the present claims should be read as to encompass any composition or pipe that meets the defined values of Mw, Mn and "lower limit of the high molecular weight (HMW) ethylene copolymer fraction" using any method that can be considered to be standard in the art in the technical context of the present claims as the method of measurement for those parameters.

2.7 Such a reading of the claim may on the one hand result in a larger number of compositions or pipes meeting the claimed values than when one specific method were used, and therefore in less difficulty to obtain compositions or pipes as defined by the claims, i.e. in less stringent requirements for assessing sufficiency of disclosure of the claimed combination of features. In that case it may on the other hand require stronger arguments in favour of novelty and inventive step, in particular if the claimed values were held to distinguish the claimed subject-matter from the prior art and to be considered essential for providing a technical effect vis-à-vis the prior art.

3. The Respondents' argument that the conventional methods for determining Mw and Mn led to different values out of which a lack of guidance resulted for the skilled person wishing to obtain the result defined in the patent specification (paragraph [0013]), namely to obtain a pressure pipe with a desired combination of good processability and good strength, cannot be accepted as an argument pertaining to sufficiency of disclosure of the invention, as those results or effects are not features of the present claims. This follows from the consideration that - in accordance with Rule 43(1) EPC - the invention in the European patent application is defined by the subject-matter of a claim, i.e. the specific combination of features present in the claim, as is reminded in Opinion G 2/98 of the Enlarged Board of Appeal (OJ 2001, 413; point 2 of the Reasons). Whether the result defined in the present patent specification (paragraph [0013]), is achieved or not, may, however, become relevant under the requirement of inventive step, for assessing the technical problem which can be held to be successfully solved by the combination of features claimed.

4. The uncertainty about which method the skilled person would select to determine Mn, Mw and the lower limit of the high molecular weight (HMW) ethylene copolymer fraction, which was the central issue addressed by the parties both in opposition and in appeal proceedings, is in the present case not adequate to make a case against sufficiency of disclosure. The argument that the choice of the measurement method for determining Mn, Mw and the lower limit of the high molecular weight (HMW) ethylene copolymer fraction had an influence on the values obtained and that therefore the skilled person would not know whether he had obtained something falling within the ambit of the claims - as it was argued by the respondents as well as in the decision under appeal - boils down to the argument that the boundaries of the claims are not clearly defined, which is a matter of Article 84 EPC, not sufficiency of disclosure. Such an objection under Article 84 EPC cannot be successful as it would not arise out of any amendment made in opposition or appeal proceedings. 

5. For assessing the requirement for sufficiency of disclosure the question should be answered whether the skilled person, following the teaching provided in the patent specification, in particular in paragraphs [0025] to [0029] and the Examples, and also taking into account his general knowledge, would be able to obtain without undue burden multimodal polyethylene compositions meeting all criteria defined in claim 1 of the patent in suit (see point 2.1 above) and the pipe according to claim 12.

5.1 In this respect, points raised before the opposition division (points 3.1.1 to 3.1.8 of the letter of 8 June 2005 of Opponents 1 and points 4.1 to 4.4 of the Patent Proprietors' letter of 19 January 2006), which in particular relate to the process conditions that are needed to obtain the combination of technical features defined in the claims, and which appear to be essential to assess the sufficiency of the disclosure, should also be considered.

5.2 However, none of those issues was decided by Opposition Division, nor argued by the parties before the Board.

6. Under those circumstances, as the essential issues to be addressed in respect of sufficiency of disclosure have not been dealt with in the contested decision, the Board exercises its discretion under Article 111(1) EPC to remit the case to the first instance for further prosecution.

For these reasons it is decided that:
1. The decision under appeal is set aside.
2. The case is remitted to the department of first instance for further prosecution.

This decision has European Case Law Identifier:  ECLI:EP:BA:2013:T005908.20130906. The whole decision can be found here. The file wrapper can be found here.

Photo by Danndalf obtained via Flickr.