T 0129/88 (Fibre) 10-02-1992

Reasons for the Decision

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

2. Admissibility of amendments

2.1.1. Turning first to the issue of whether the present claim, as amended, would be sufficiently clear for the purposes of Article 84 EPC, in the view of the Board, in some circumstances a claim may be open to objection if the invention is defined solely in terms of desirable features. However, as was indicated by this Board in its earlier decision T 487/89 of 17 July 1991 (not published in OJ EPO), there may be circumstances where the scope of a claim is adequately restricted by the presence of other features, which impose a practical limit on open-ended features expressing "desiderata". Whether a claim which expresses desiderata is sufficiently defined has to be decided on the facts of each individual case.

2.1.2. As was stated by the Board in the above mentioned case; "3.5 The second objection of insufficiency was based on the fact that both the tenacity, and the toughness .... had been indicated with a lower, but without any upper limit. The Opposition Division took the view that such "open-ended" parameters are always objectionable if they relate to an inherently desirable characteristic. The Board does not accept that view in its generality. Whether the absence of an upper or lower limit is acceptable in a claim in any individual case depends on all the surrounding circumstances. Where, as in the present case, the claim seeks to embrace values which should be as high as can be attained above a specified minimum level, given the other parameters of the claim, then such open ended parameters are normally unobjectionable."

2.1.3. In the circumstances of the present case, the Board cannot fail to observe that out of a total of 7 features expressed in the claim, at least four of them express desiderata. Nevertheless, the Examining Division was prepared to accept the claim as being sufficiently defined for the purposes of Article 84 EPC, and in the present circumstances the Board agrees with that view.

2.1.4. The Board regards it as being a matter of technical fact that a claim which is expressed in terms of the combination of a number of desiderata may, depending on the circumstances, be effectively limited in its scope. To illustrate, in the field of metallurgy, it is well known that hardness, and impact strength, are properties which are normally inversely related to each other. An increase in hardness usually involves a loss of impact strength, and vice-versa. While a claim to alloys of a given composition having above a minimum level of hardness might be open to objection, as being a speculative claim to alloys having levels of hardness which have yet to be found, the inclusion of a further open ended limitation, such as to a minimum level for impact strength, could impose a severe practical upper limit on the hardness figure, and thus overcome any objection that the claim is of undue breadth.

2.2.1. The admissibility of the present amended Claim 1 further depends on whether it is permissible, in accordance with the EPC, to add process features to a product claim, which do not apparently affect the scope of the claim. This amendment is sought by the Appellant in response to an objection raised in the opposition by the Respondent, and is intended to ensure the validity of the patent in Germany.

2.2.2. Regarding this, in the decision T 150/82, OJ EPO 1984, 309 (mentioned in V. above) the Board indicated that under the provisions of the EPC, product-by-process claims are not normally acceptable, a view which the present Board endorses. It went on to suggest (at point 10 of its decision, page 316 of the published report) that product- by-process claims, "should be reserved for cases where the product cannot be satisfactorily defined by reference to its composition, structure or some other testable parameters".

Again, the Board finds itself broadly in agreement with what has been said in the earlier case.

2.2.3. However, the observations in the last-mentioned earlier decision do not deal with the issue which arises in the present case, which may be formulated thus. On the assumption that in one or more Contracting States claims may not be characterized by desiderata, is there any provision in the EPC or the Implementing Regulations which forbids the EPO from permitting a product-by-process claim which is intended to overcome that objection?

2.2.4. In terms of the above quoted decision T 150/82, it may be said that under such circumstances, the invention indeed cannot be "satisfactorily defined" without reference to the process, because it would be unsatisfactory for the EPO to refuse to allow the addition of a feature which would possibly ensure the validity of such a claim in certain Contracting States. Besides, in the view of the Board, the effect of bringing process limitations into the present Claim 1 is likely to impose some practical limitation on the otherwise open-ended effect of certain features there expressed. Thus, although tenacity is expressed as being at least 10 cN/dtex, with no upper limit, the process limitations are likely to have the effect of imposing a practical upper limit. Consequently, the Board can see no valid objection to the introduction of process criteria in the present circumstances.

2.3. The introduction of the process criteria into Claim 1 is based on the disclosure at page 1 lines 1 to 17, and page 5 line 34 to page 6 line 1, of the application as originally filed, corresponding to page 2 lines 5 to 11, and page 3 lines 56 to 60, of the specification of the patent as granted. As indicated in 2.2.4 above, the scope of the claim is thereby limited compared to Claim 1 as granted. Accordingly, the Board is satisfied that the amendment is allowable for the purposes of Articles 123(2) and 123(3) EPC.

3. Prior public use

3.1. Although a Board of Appeal (and equally an Opposition Division) has an obligation under Article 114(1) EPC to investigate matters of its own motion, that obligation does not extend as far as investigating an allegation of prior public use, where the party who formerly made that allegation has withdrawn from the proceedings, and it is difficult to establish all the relevant facts without his cooperation.

3.2. The reason for this is that the obligation to investigate of its own motion imposed on the EPO by Article 114(1) EPC is not unlimited in its scope, but is confined by considerations of reasonableness, and expediency. No department of the EPO ought to expend excessive time or effort on any one case, with consequent detriment to the rest of its activities. If a party to an opposition raises an allegation, such as of prior public use, or of prior oral disclosure, he alone may often be in possession of all the relevant evidence which may be needed to establish that issue. If he then withdraws from the opposition, thereby indicating that he is no longer interested in the outcome of the opposition, then, although the EPO may have the power, depending on the country of residence of relevant witnesses, to compel them to give evidence, either before the EPO or before the court of a Contracting State, in the interest of procedural economy it should not normally investigate the issue any further. The relevant principles in relation to German law are discussed in Schulte, Patentgesetz, (4th edition, Carl Heymanns Verlag) section 35 note 9 page 303. In the Board's view, the same principles are applicable under European law.

3.3. It would be different if a relevant prior public use had, e.g., already been substantiated by documents of undisputed authenticity, or if, as occurred recently (T 629/90, 4 April 1991, not published in OJ EPO), the material facts with respect to the alleged prior public use were undisputed by the Appellant (Patentee).

3.4. Accordingly, the Board finds the allegation of prior public use unestablished in the present case.

4. Novelty in relation to cited documents

4.1. An alternative basis for attacking the novelty of the invention was based by the Respondent on the allegation that the inevitable consequence of making a product in accordance with Example 2A of document (2) was that that product would have all the properties of a polyamide fibre made in accordance with Claim 1 of the patent in suit. However, as was pointed out by the Opposition Division, the accuracy of the repetition of Example 2A was credibly contested. The Board has reviewed the arguments directed to this issue, and is not satisfied that the alleged repetition performed by the Respondent was a satisfactory duplication of Example 2A.

4.2. In addition, it is noted that comparative tests contained in the patent in suit (page 8 lines 34 to 65) show that fibres which had been made by a process which very closely resembled that of the said Example 2A of document (2) had considerably inferior heat sensitivity properties when compared with those made in accordance with the invention. Accordingly, the Board is not satisfied that novelty is lacking on this ground.

4.3. Following the withdrawal of the opposition, the Board sees no sufficient reason to investigate the matter in further detail, and therefore adopts the finding of the Opposition Division on novelty.

5. Inventiveness

5.1. The argument by the Respondent before the Opposition Division was directed principally to the allegation of lack of novelty based in the alternative on prior public use, or the inevitable result of the repetition of Example 2A of document (2). However, inventiveness was also challenged on the basis of document (9). It discloses the mixing of a number of solid polymers with frozen solvents, prior to heating and extrusion to produce fibres, the solvents including water, dimethyl sulphoxide, benzene, and m-cresol mixed with phenol (pages 3 and 4 of the translation).

5.2. Although document (9) is concerned with a method which resembles that of the present invention, i.e. a mixing step carried out at a low temperature, prior to heating of the mixture and extrusion of a fibre, the systems with which it is concerned do not include polyamides in sulphuric acid, and it is not in any way concerned with the problem of the invention, which is to achieve particularly low heat sensitivity in such fibres. A comparison of the heat sensitivity figures given in the patent in suit for the Examples in accordance with the invention, as against the comparative Examples II(A) and II(B), shows credibly that a significant improvement in heat sensitivity is attainable in accordance with the invention.

5.3. The skilled reader of document (9) might appreciate that the technique there disclosed is capable of application to polyamide fibres, possibly in the presence of sulphuric acid, but there is no suggestion that the adoption of that procedure in the polyamide/sulphuric acid system would afford any particular advantage, still less the particular advantage attained in accordance with the invention. Consequently, the Board does not consider that this document renders the present invention obvious, and the objection of lack of inventive step is rejected. Taking into account the age of the present appeal, the fact that the opposition has been withdrawn by the Respondent, and the Board's view that the issue of inventiveness is not open to serious dispute in the light of the cited prior art, in the exercise of its discretion under Article 111(1) EPC the Board saw no reason to refer that issue back to the Opposition Division.

6. Conclusion

As the Board has rejected all the attacks on the patent, it allows the Appellant's Main Request, and has no need to comment on the Auxiliary Requests. The subject matter of Claim 1 of the patent in issue is accepted to be novel, and involves an inventive step as required by Articles 54 and 56 EPC, and the claim is therefore patentable. The dependent Claims 2 to 10 relate to modifications of the fibre covered by Claim 1, or a thread bundle, or a cord, all made of fibres falling wholly within the scope of Claim 1, and on that ground alone they are also entitled to be upheld.