T 0018/81 (Olefin polymers) of 1.3.1985

Summary of Facts and Submissions

I. European patent application No. 78 200 028.5 filed on 1 June 1978 and published on 20 December 1978 (publication No. 0 000 084) claiming priority of the earlier application in France of 7 June 1977 was refused by decision of the Examining Division of the European Patent Office of 10 February 1981. The decision was based on the claims received on 5 March 1980. Claim 1 read as follows: "1. Use, for an extrusion process followed by water cooling of the extrusion, of compositions based on alpha-olefin polymers comprising: (a) at least one phenolic anti-oxidant, (b) at least one organic phosphite, (c) at least one alkaline-earth metal carbonate."

II. The reason given for refusal was lack of inventive step. Since compositions comparable to those characterising the subject-matter of Claim 1 had been described and/or suggested in the prior art represented by US-A-2 985 617 and 2 991 264, the use of such compositions in an extrusion process followed by water hardening of the extrusion could not constitute a patentable invention since the hardening operation itself was well known and frequently employed with extrusion processes. The inventive contribution alleged by the applicant had been merely to discover interesting properties in the extrudable composition described and/or sufficiently suggested and to attribute them to the presence of calcium carbonate, the preferred constituent. He did not have to adapt the compositions especially.

III. The applicant filed an appeal against this decision on 23 March 1981 and submitted a Statement of Grounds on 27 May 1981. He requested that the decision of 10 February 1981 to refuse the application be revoked in its entirety and that the appeal fee be reimbursed.

IV. In his statement of Grounds, the appellant pointed out that US-A-2 985 617 had been drafted with the manifest intention of disclosing as extensively as possible the use of different compounds for stabilising polyolefins produced with the aid of Ziegler catalysts at a time when these catalysts had only just been disclosed. Indeed, any stabiliser of polyvinyl chloride would seem suitable for stabilising these polyolefins.Alkaline-earth metal carbonates are in no way preferred. This document does not especially recommend employing either one of the elements (a), (b) or (c) of the composition used according to the invention or an extrusion process followed by water hardening. Moreover, US-A-2 991 264 discloses neither the element (a) nor the element (b) of the compositions used according to the invention. Although various hardening techniques are disclosed, water hardening is not mentioned explicitly.

Reasons for the Decision

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

2. The original Claim 1 related to a process for extruding the compositions featured in the Claim 1 finally submitted, followed by water cooling of the extrusion. The changing of a claim relating to a process using a composition into a claim relating to the use of this composition in such a process is acceptable. These are two types of claim of the same category which involve the same operations. Claim 1 therefore complies with Article 123(2) EPC. The same applies to Claims 2-10 obtained by making an identical change to the original Claims 2 - 10.

3. The nearest state of the art may be regarded as exemplified in FR-A-1 345 203. This patent describes olefin polymer compositions containing an organic thiophosphite and an inorganic base such as a carbonate of a metal of group 2, for example calcium carbonate (page 5, summary 1; page 3, left-hand column lines 17 and 18). They can also contain a phenolic anti-oxidant (page 3, right-hand column, line 18). Thiophosphites can certainly be regarded as included among the phosphites envisaged in the application (see original page 4, lines 14 to 19). Although the three constituents according to the application are mentioned explicitly, one of them - the phenolic anti oxidant - is only optional (page 3, column 2, lines 17 to 20) and the carbonate of a metal belonging to group 2 in the periodic table is only an alternative in a list comprising numerous equivalents (page 5, summary 1(b)). The compositions described in this patent can be used for making articles by extrusion (page 3, column 2, lines 30 to 34).

4. The compositions described in Claim 1 of the application are, considered as a selection, new, a fact which has never been contested. In the application, the use of the compositions described in Claim 1 is envisaged in the extrusion process followed by water cooling of the extrusion. But it also has to be said that, in order to produce films, an extrusion process must be followed by cooling. This can be done by means of cold air, cold water or cooled cylinders (see, for example, Plastics Engineering Handbook, 4th ed. 1976, pages 174 - 176). Consequently, the extrusion process envisaged in FR-A-1 345 203 incorporates the cooling stage in any of its three forms. However, it may be concluded that, vis-à-vis the state of the art referred to above, the subject-matter of Claim 1 of the application is new in so far as the use of new compositions relates to an extrusion process followed by water hardening.

5. To establish the existence of an inventive step, it will be necessary first of all to address the problem which the application seeks to resolve. In using his compositions, the applicant has in mind those extrusion processes in which the cooling stage consists in water hardening. These processes are known for the disadvantages they involve in connection with the series of operations which the worked objects have to undergo. These disadvantages include surface defects and are due to the more or less substantial quantities of cooling water which are carried along as the object being extruded moves forward. The problem with which the application is concerned is therefore to reduce the extent to which water is carried along. The applicant has resoved this problem by recommending the use of a combination of the additives (a), (b) and (c).

6. The applicant set forth the original examples 1 - 3 as evidence that the problem has been resolved. These examples indicate that, when specific compositions according to the application are used, water is not carried along when the extrusion speed reaches 40m/min., whereas one of the examples adduced by way of comparison shows this phenomenon occurring already at a speed of 12m/min. Further tests carried out at the request of the Examining Division, the results of which were submitted on 10 September 1980 and received on 13 September 1980, confirm these results. It should be noted here that the Examining Division had already regarded these comparative tests as seeming to indicate an advantageous effect (see decision of 10 February 1981, point 5). Moreover it had said that the use of clearly specified compositions producing conclusive surprising results seemed patentable (see communication of 27 March 1980, point 3).

7. The solution proposed in the present application could not be derived from FR-A-1 345 203, which deals with a different problem (cf. point 5 above) namely how to obtain good heating and light-resistance irrespective of the extrusion process chosen. Nor could it be derived any more readily from the other prior-art documents cited during the procedure, which do not in any case relate to the problem raised in the application, namely the reduction in the amount of water carried along. The same applies to the two patents on which the decision to refuse the application was based: - US-A-2 985 617 relates to the stabilisation of Ziegler polymers; - US-A-2 991 264 cites only calcium carbonate as a nucleation agent. Similarly, GB-A-584 620, which is quoted incidentally in the decision to refuse the application, says only that calcium carbonate can improve the mechanical properties of the ethylene polymer. Finally, FR-A-1 296 276, which is quoted in the search report, and referred to in the first communication from the Examining Division, envisages a composition for increasing resistance to crack formation, containing carbonates covered with a layer of a higher fatty acid and/or one of its salts or esters. Although a certain similarity between the problems can be recognised, the solution proposed is different.

8. None of the foregoing documents could have prompted a person skilled in the art to choose the water cooling method. Admittedly, one of them mentions water and the other means of cooling (US-A-2 985 617, column 12, line 72 to column 13, line 2). However, the Board has taken note of the specialised manual "Extrudierte Feinfolien und Verbundfolien" (1976) VDI Verlag, pages 18 and 19. According to this manual, air is the only cooling agent which can be used for films, since water baths and devices with cooling surfaces easily cause surface defects, a grave disadvantage in the case of films. The Board considers that a prejudice therefore existed against the method chosen in the application. It believes that this dismissal of the water cooling method would divert the skilled person from the idea, given the problem in question, of trying to reduce the quantity of water carried along when extruded polymer films are cooled in this way. The fact that this prejudice was overcome by the applicant constitutes a significant indication of an inventive step. The solution to the problem in question, as advocated in the application, does not follow from the state of the art.

9. In conclusion, the teaching of the application under consideration must be regarded as surprising, whether expressed in accordance with Claim 1 or its sub-claims, and consequently as involving an inventive step.

10. The applicant requests that the appeal fee be reimbursed in accordance with Rule 67 EPC. He maintains that the decision to refuse the application is based essentially on two documents which he had produced himself, but whose utilisation as a basis for the decision to refuse the application he could not have foreseen. The procedure for the granting of a European patent is based on due process of law. Article 113(1) EPC indicates that a decision may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments. In the event, this principle was ignored by the Examining Division in so far as the applicant had no opportunity to discuss the relevance of the decisive opposing argument based on documents of which he was admittedly aware and which he had himself then introduced into the debate, but with a completely different aim. In these circumstances the decision to refuse the application was in contravention of Article 113(1) EPC. The Board considers that this constitutes a substantial procedural violation and that it is therefore equitable to order the appeal fee to be reimbursed in accordance with Rule 67 EPC.

ORDER

For these reasons, it is decided that:

1. The decision of the Examining Division of the European Patent Office of 10 February 1981 is set aside.

2. The matter is referred back to the department of first instance with the order that a European patent be granted on the basis of the following documents: Claims 1 - 10 received on 5 March 1980 pages 1, 1 bis, 2, 2 bis and 3 received on 28 September 1984, pages 4, 5, 6 and 6 bis received on 5 March 1980 and the original page 7.

3. Reimbursement of the appeal fee is ordered.