T 0609/88 10-07-1990

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

2. The admission at a late stage of a new set of claims substantially different from the old ones is discretionary (Rule 86(3) EPC, second sentence) and the Board would normally refer the question of admissibility to the first instance. In the present case, where the submission of the new claim has been the result of the Appellant's own voluntary citation of a new document (document (6)), the appropriateness of submitting the new claim is sufficiently clear to enable the Board, by way of exception, to decide upon admissibility under its discretionary power (Article 111(1) EPC) and to admit the claim.

3. The wording of the claim now under consideration does not give rise to objections under Article 123(2) EPC.

The use of polymers containing the recurring units (i) and (II) for the production of moulded articles corresponds to the application of the polymer prepared in Example 1 (page 13, lines 1 to 6 and page 14, Table I of the original documents). The two recurring units and their ratio are disclosed in original Claims 1 and 5; the three starting compounds correspond to the first three of the preferred monomers referred to on original page 6, lines 20 to 22; these structural requirements are combined with various operative features concerning the presence of an alkali metal carbonate (page 9, lines 10 to 15), the use of polar aprotic solvents (page 8, line 1 to page 9, line 6) and the substantially anhydrous conditions (page 9, line 16 to page 10, line 7).

4. Once an admissible appeal has been filed, the Board of Appeal has the responsibility for deciding the appeal in place of the department which was responsible for the decision under appeal. It may thus either exercise any power within the competence of the Examining Division or remit the case to the Examining Division for further prosecution (Article 111(1) EPC). However, as laid down in the decision T 63/86 of 10 August 1987 published in OJ EPO 1988, 224, the limit to which this power applies is determined by the extent to which the claims have been amended (point 2, third paragraph). In case of major amendments which raise new issues and require a substantial further examination, such further examination should, as a general rule, be carried out by the first instance.

In the present case, the claim on file differs significantly from Claim 1 of the set of claims rejected by the Examining Division. Whilst the new claim is directed to the use of a specific polymer for the production of moulded articles, the old one was concerned with the preparation of such polymer. Although, for the reasons stated in point 2 above, the Board has exercised its own discretion under Rule 86(3) EPC and ruled that the new claim was prima facie admissible, such a substantial degree of amendment of the scope of protection in itself justifies the remittal of the case to the Examining Division for carrying out a fresh examination.

5. Moreover, as follows from points III and IV above, the documents which seem to be the most relevant are documents (4) and (6) which were not taken into consideration by the decision under appeal.

5.1. As noted by the Appellant in the Statement of Grounds of Appeal (page 4, line 19 to page 5, line 1), a process for preparing a copolymer based on the recurring units (i) and (II) is known from document (4).

According to Example 1, Bisphenol A is first reacted with sodium hydroxide to produce the bisphenolate which is then polycondensed with an equimolar amount of 4,4'-bis-(4-chlorophenylsulfone)-diphenylether to produce a polyarylethersulfone of formula:

(FORMULA) Emphasis is put on the good mechanical properties and dimensional stability of this polymer over a wide temperature range which allows the use thereof in the manufacture of shaped articles by injection moulding, extrusion and compression moulding processes, as well as in the electrical industry (column 1, lines 47 to 59). With regard to this teaching, the subject-matter of the present claim only differs in the method chosen to prepare the aromatic polyethersulfone.

5.2. Document (6) is a survey of the preparation of various polyethersulfones by reacting 4,4'-dichlorodiphenylsulfone with one or more bisphenols using the so-called potassium carbonate/N-methylpyrrolidone route. Polycondensation is achieved in presence of toluene which acts as an azeotrope forming solvent ensuring anhydrous conditions and thereby high molecular weights (page 284, section "Experimental"). According to Table II, page 285 (second Example), a copolymer is prepared from a mixture of 2,2-bis(4- hydroxyphenyl)propane and 4,4'-dihydroxydiphenylsulfone, i.e. respectively Bisphenol A and Bisphenol S, used in equimolar amount, thus giving rise to a copolymer based on the recurrent units (i) and (II) in the ratio 75:25.

Although moulding operations are not explicitly envisaged in this article, the combination of properties mentioned there in general terms, i.e. hydrolytic, thermal and dimensional stability, over a wide use temperature range as well as good mechanical properties (page 284, section "Introduction", paragraph 1), can only be interpreted by the skilled man as a list of requirements to be fulfilled by a polymer suitable for such moulding operations, as evident from point 5.1 above.

5.3. Thus, in the Board's view, documents (4) and (6) appear sufficiently relevant to require substantive examination on a new basis.

6. For both reasons, i.e. in view of the drastic amendment of the claimed subject-matter and of the fact that the highly relevant documents were not considered in the decision under appeal, the Board deems it appropriate to make use of its power under Article 111(1) EPC and to remit the case to the first instance, so as not to deprive the Appellant of his right to two levels of jurisdiction.