T 0749/89 16-12-1992

Reasons for the Decision

1. The appeal is admissible.

2. Reference to new document

At the start of the oral proceedings the Board refused to admit a further document referred to by the Appellant in its Grounds of Appeal. It was excluded by the Board in the exercise of its discretion under Article 114(2)EPC, since the Board did not consider that the new document was relevant for the purposes of supporting the Appeal.

3. Novelty

Novelty is not in issue, and the Board is satisfied that no valid objection of lack of novelty can be maintained on the basis of the cited prior art.

4. Closest prior art

Document (2), which is regarded as the closest prior art, is referred to in the patent in suit at page 2, lines 25 to 35. It discloses the coupling of pure and substantially anhydrous aryl and heteroaryl polyhalide monomers in an aprotic solvent under anhydrous conditions using a catalyst mixture of a nickel compound and a ligand in the presence of a reducing metal. That disclosure corresponds with the process steps identified in feature (iv) of Claim 1 in suit, and the contrary was not asserted by the Appellant.

5. Problem

Seen against the disclosure of document (2), the problem with which the patent in suit is concerned is to find a more economic alternative to the process there disclosed.

6. Solution and its effectiveness

The solution proposed in accordance with the alleged invention is an integrated process comprising the process in accordance with document (1), which discloses essentially steps (i) to (iii) of the process of Claim 1 in suit, subject to the qualification that document (1) is concerned with the production of polymeric materials, whereas in accordance with the alleged invention, monomers are required for subsequent processing; and the process of document (2) as step (iv). It is accepted by the Board, that the skilled reader of document (1), who wanted to produce monomers rather than polymers, would know as a matter of general knowledge that this would be attainable by a suitable adjustment of the proportions of the reactants. That the process in accordance with document (1) is capable, in principle, of providing a suitable starting material for step (iv) was not in issue, and the Board is satisfied that there is inherent economy in carrying out the integrated process in accordance with the alleged invention, as contrasted with separating and purifying the product of the process of document (1), before subjecting it to the catalytic treatment disclosed in document (2).

7. Inventiveness

7.1. The issue of inventiveness turns on whether a skilled person, having as his starting point the disclosure of document (2), confronted with the problem of finding a more economic alternative thereto, and having also at hand the disclosure of document (1), which discloses a route to suitable starting monomers, would have thought of combining the two steps into an integrated process, without introducing the further step of isolation and purification of such monomers. In the view of the Board, the answer to that question would have to be affirmative, unless there were some sufficient disincentive which would dissuade the skilled worker from making that combination.

7.2. It is well established in the case law of the Boards of Appeal (see e.g. T 119/82 "Gelation/EXXON" OJ EPO 1984, 217) that inventiveness can sometimes be established by demonstrating that a known prejudice, i.e. a widely held but incorrect opinion of technical fact, needed to be overcome. In such cases, the burden is on the patentee (or applicant for a patent) to demonstrate, such as by reference to suitable technical literature, that the alleged prejudice really existed.

7.3. The existence of a known prejudice in the art is no more than one example of a factual situation which might deter the skilled worker from adopting a particular step. No less common is the situation, such as is asserted by the Appellant in the present case, that there are good technical reasons why the skilled worker would have been deterred from adopting a given step. In such cases, if in an opposition the patentee advances credible argument to demonstrate why the skilled worker would have been deterred, the burden is transferred to the opponent, either to show that the facts alleged are incorrect, or that although the facts asserted are correct, there are good reasons why the skilled worker would nonetheless not have been significantly deterred.

7.4. In the present case, the Opposition Division held (Decision, page 7, paragraph 10) that the Appellant had failed to demonstrate the existence of a prejudice by failing to cite a body of literature in support of the existence of such a prejudice. However, what was asserted here was not the existence of a known "prejudice in the industry", the kind of situation covered by the case law mentioned above, but instead the existence of a plausible technical deterrent.

7.5. On pages 5 to 7 of its statement dated 15 November 1988 filed in response to the opposition, the Appellant asserted that it was well known in the industry that catalyst systems of the kind described in document (2) were extremely sensitive to being contaminated or poisoned by any impurities contained in the starting materials. Consequently, the Appellant argued that the skilled worker would not think of using the products of the process of document (1) without an intervening purification step. That argument was still further elaborated by the Appellant at page 4 of its letter dated 23 June 1989, where seven detailed reasons were given to support the Appellant's contention that considerations of the nature of the reactions involved would dissuade the skilled worker from combining the two processes, for fear that impurities from steps (i) to (iii) could poison the catalyst in step (iv).

7.6. The Respondent did not contest the known sensitivity of the catalyst, but argued at the oral proceedings that the skilled worker had good reason not to fear the presence of deleterious impurities remaining associated with the monomer produced in steps (i) to (iii). The skilled reader of document (1) would have seen that it involved a condensation reaction, of the kind which was unlikely to give rise to any side reactions, and resultant impurities.

7.7. Whereas the Appellant in its written submissions gave detailed support for its contention that there were sound technical reasons why a skilled worker would have been deterred from combining the processes of documents (1) and (2), there was no written refutation by the Respondent, although that deficiency was made up to some extent by arguments advanced during the oral proceedings. Although the Board finds some of the above mentioned seven reasons advanced by the Appellant less than convincing, nevertheless the Board accepts the fact that the skilled worker might reasonably have expected, taking into account the probabilities imposed by the law of mass action, that some of the phenolate which is formed in step (i), would not have reacted completely, even in the presence of an excess of the dihalobenzoid compound in step (ii). He would thus reasonably have expected that, in the absence of a separation and purification step, there would be some residual free phenolate left in the reaction products in step (iii), which could poison the catalyst in step (iv).

7.8. In the Board's view that expectation would have been sufficient to have deterred the skilled worker from combining the processes of documents (1) and (2), without any intervening separation and purification step, and it needed an inventive step to overcome that deterrent.

8. The subject-matter of Claim 1 of the patent in issue thus involves an inventive step as required by Article 56 EPC, and the claim is therefore patentable. The dependent Claims 2 to 25 relate to modifications of the integrated process falling wholly within the scope of Claim 1, and on that ground alone they are entitled to be upheld.