T 1002/95 10-02-1998

1. The appeal is admissible.

2. Preliminary considerations

2.1. In its notice of appeal the appellant mentioned all three grounds of opposition in accordance with Article 100(a), (b) and (c) EPC raised in the opposition proceedings.

It can be derived from the file that the Opposition Division considered the objections according to Article 100(b) and (c) EPC raised against the granted patent not justified and was of the opinion that the appellant itself had admitted that the subject-matter of the granted claim 1 interpreted in the manner as done by the Opposition Division did not infringe the respective requirements (see the communication dated 22. March 1993, point 1). Since only arguments in respect of lack of inventive step had been submitted by the appellant against the amended claims, the Opposition Division apparently came to the conclusion that the other grounds of opposition had not been maintained (see the decision under appeal, page 2, 6th paragraph).

However, no evidence is derivable from the file that the objections based on Article 100(b) and (c) EPC indeed had been withdrawn so that the Opposition Division's conclusion must be considered to be based on a misinterpretation of the facts. The Board is of the opinion that in the present case the misinterpretation amounts to a failure of judgement rather than a procedural violation.

Having regard to the power given to the Board by Article 111(1) EPC and the circumstances of the case, in particular its age, the Board considers it appropriate to decide on the issue of Article 100(b) EPC in the present appeal proceedings rather than to refer the case back to the Opposition Division for proper consideration of this further ground of opposition. The objection under Article 100(c) EPC was no longer maintained during the appeal proceedings.

3. Amendments

3.1. Current claim 1 is based on the originally filed claim 1 concerning a flexible composite pipe and is limited to the use of such a pipe for transporting high temperature oil or gas from a submarine oil field. Such a specific use follows from the statements in the originally filed description on page 1, lines 1 to 4, as well as from the objects to be fulfilled cited on page 3, lines 5 to 18.

Present claim 1 therefore meets the requirement of Article 123(2) EPC.

Since, when compared to the scope of the granted claim 1, the present claim 1 is limited both in respect of the use of the flexible pipe and in respect of the nature of the polymeric material forming the inner pipe which is now restricted to three specific (i, ii, and iii in claim 1) polymeric materials falling within the granted more general specification of the polymeric material for the inner pipe, also the requirement of Article 123(3) EPC is fulfilled.

The formal acceptability of claim 1 in respect of the requirements of Article 123(2) and (3) EPC was in fact not contested by the appellant.

3.2. The appellant objected in general to the admissibility of the further amendment to claim 1 in its form as it was upheld by the Opposition Division because the respondent was not the appealing party. Therefore, unlike the rights it would have had as an appellant, its requests were subject to restrictions as was specifically set out in the Enlarged Board of Appeal decision G 9/92 (supra).

Moreover, because of the deficiency of claim 1 upheld by the Opposition Division in respect of the requirement of Article 123(2) EPC making the patent null and void the appellant considered himself effectively in a worse position than when compared to the situation if no appeal had been filed. Such situation amounted to a "reformatio in peius" with respect to the appellant and should not be allowed having regard to G 9/92 and also to the decision T 923/92, point 40 (supra).

3.3. Although in the Board's view the above objection is without a factual basis since claim 1 as amended is narrower in scope than that accepted by the Opposition Division the Board would like to give its opinion on the legal issue raised.

As was pointed out during the oral proceedings, new Rule 57a EPC applies in the present case. This Rule, inserted by decision of the Administrative Council of 13. December 1994 and entering into force on 1 June 1995 (OJ EPO 1995, 9) explicitly allows amendment of the description, claims and drawings of a patent provided that the amendments are occasioned by grounds of opposition specified in Article 100 EPC, even if the respective ground has not been invoked by the opponent. There is no time limit for such amendment. Thus the patentee's right to amendment on its own motion also applies to the appeal proceedings. Given the fact that claim 1 upheld by the opposition division is defective in respect of the opposition ground pursuant to Article 100(c) EPC, Rule 57a EPC clearly gives the non-appealing patent proprietor the right to amend claim 1 to remove this ground of opposition.

3.4. Moreover, the Board does not follow the appellant's interpretation of the conclusions arrived at in the decision G 9/92 (supra) (or the decision with identical content G 4/93).

In its decision G 9/92 the Enlarged Board of Appeal (see points 15 and 16 in conjunction with points 8, 10 and 11) states that a patent proprietor who has not filed an appeal is only a party to the proceedings and that therefore his requests are subject to limitations and he is "primarily" limited to defend the version of the claims accepted by the Opposition Division.

However, this conclusion cannot be construed to exclude that amendments to the patent may be proposed by the patent proprietor if those amendments are intended to remove deficiencies in respect of the requirements of the EPC which should be fulfilled if the patent is to be maintained in amended form (see Article 102(3) EPC). Such amendments clearly are "appropriate and necessary" in the sense of the considerations given in point 16 of the decision G 9/92 (supra), which is the main condition required by this decision of the Enlarged Board of Appeal in respect of the proposed amendments (see also the decision T 752/93 of 16 July 1996, points 2.3 and 2.4, not published in the OJ, referred to by the respondent).

3.5. In any case it should be noted that the decisions G 9/92 and G 4/93 were taken by the Enlarged Board of Appeal prior to the insertion of Rule 57a into the EPC. Hence the patent proprietor's enhanced right to amendments could not be considered in those decisions.

4. Sufficiency of disclosure (Article 100(b) EPC)

4.1. The appellant was of the opinion that the use claimed in claim 1 was not disclosed in a manner sufficiently clear and complete to be carried out by a skilled person in the art since there was no basis for the alleged resistance in respect to temperatures of more than 100°C and pressures of 300 bars occurring during the claimed use of the composite pipe.

4.2. For deciding on the fulfilment of the requirement of Article 100(b) EPC solely the disclosure of the patent and its interpretation by the skilled person is decisive.

From the description of the patent specification can be derived that the composite pipe claimed should withstand temperatures exceeding 100°C and the pressure of oil or gas coming from a submarine oil field. However, no specific values of temperature and pressure or of combinations of those two parameters are included in claim 1. Therefore the minimum requirement for satisfying the claimed use is met if the composite pipe defined in claim 1 can withstand a temperature just above 100°C and a pressure value corresponding to that normally exerted on known flexible composite pipes for transporting high temperature oil or gas from a submarine field.

The Board has no doubt that such requirements are fulfilled by the flexible composite pipe defined in claim 1 because its general mechanical structure is not different from composite pipes known from D1 or D12 and as far as the material of the composite pipe is different from that of these known composite pipes only the inner pipe is concerned. The material for the inner pipe in accordance with the three alternatives claimed is based on PVDF copolymer resin which, when having regard to the properties of the PVDF copolymer Solef 11010 as disclosed in D2, has both good flexibility and thermal stability up to temperatures of 320 F (160 C).

Also taking into account example 7, referred to in the patent specification, the inner pipe material Solef 11010 allowed circulation of oil heated to a temperature of 120°C at a pressure up to 950 Bars.

4.3. Although the exact circumstances of the tests carried out by the appellant are not specified, at least the results of these tests in respect of the copolymers Solef 11010 (D2) and Kynar 2800 (D4) as shown in the graph introduced by the appellant with its letter dated 30. January 1998, are not in contradiction with these findings. On the contrary, in so far as this evidence can be considered relevant (because it only concerns the resistance to blistering in respect of the gas methane (CH4)), apparently pressures up to 480 (Kynar 2800) and 300 bar (Soleff 11010) can be applied at temperatures above 100 C.

4.4. On the other hand, no evidence is available for support of the respondent's allegations that the composite pipe used in claim 1 prolongedly resisted temperatures of up to 130°C and internal pressures of up to 1380 bar (see the response dated 23 December 1997).

These values have no basis in the patent either, in which it is explicitly stated that further measures are necessary to allow use at high temperature and high pressures at the same time (see page 3, lines 60 to page 4, line 15).

Although this lack of evidence does not affect the issue of sufficiency of disclosure of the subject-matter of claim 1 the alleged facts cannot be taken into account for support of inventive step of the subject-matter claimed (see point 5 below).

5. Novelty and inventive step (Article 100 EPC)

5.1. Novelty of the use claimed in claim 1 follows from the fact that the available prior art does not disclose the use of a composite pipe for transporting high temperature oil or gas from a submarine oil field having an inner pipe of polymeric material selected from (i) polyvinylidene fluoride copolymer resin, (ii) a blend of polyvinylidene fluoride copolymer resin and polyvinylidene fluoride resin, and (iii) a composition based on a polyvinylidene copolymer resin, the polymeric material having, when hot pressed into a sheet, an Izod impact strength of not less than 9.81 daN cm/cm (10 kgcm/cm) and an apparent Young's modulus in tension of not more than 88.3 daN/mm2 (90 kg/mm2).

In fact, novelty of the claimed use was not in dispute.

5.2. The closest prior art is represented by D1. This document undisputedly discloses the use of a flexible composite pipe for transporting high temperature oil or gas from a submarine oil field (see column 1, lines 10 to 27), the known flexible pipe comprising an inner pipe (12) obtained by extruding polymeric material consisting of fluoroplastics, a reinforcing layer (14) formed around said inner pipe and a protective sheath layer (17) coated around said reinforcing layer.

Although the known flexible pipe is suitable for the intended use of transport of oil or gas from a submarine oil field manufacture of this known flexible pipe is difficult mainly because of the high extrusion temperatures needed and consequently the special equipment necessary for extrusion of the fluoroplastics such as Tefzel, Teflon FEP and Teflon PFA referred to in D1. Furthermore, the resulting high shrinkage of the material induced stresses and led to a risk of crack propagation.

5.3. The object of the present patent is therefore to be seen in the provision of a composite pipe for transporting high temperature oil and gas from a submarine oil field which has a range of properties that are necessary to withstand prolonged exposure to high temperature oil and gas from a submarine field while allowing manufacture on conventional extrusion equipment.

The patent in suit solves this technical problem essentially by providing for the inner pipe of the composite pipe known from D1 a polymeric material selected from (i) polyvinylidene fluoride copolymer resin, (ii) a blend of polyvinylidene fluoride copolymer resin and polyvinylidene fluoride resin, and (iii) a composition based on a polyvinylidene copolymer resin, the polymeric material having, when hot pressed into a sheet, an Izod impact strength of not less than 9.81. daN cm/cm (10 kg cm(cm) and an apparent Young's modulus in tension of not more than 88.3 daN/mm2 (90 kg/mm2).

It is undisputed that both Solef 11010 (D2 and D3) and Kynar 2800 (D4) fall within the scope of the materials claimed, at least in respect of alternative (iii).

5.4. The skilled person looking for a solution to the technical problem outlined above is considered to be an expert well acquainted with the manufacture of the type of composite pipes involved in transportation of oil and gas of submarine oil fields and as such is well aware of the range of necessary properties required for the materials used for the manufacture of this particular sort of flexible composite pipes and the respective shortcomings of some specific properties of the materials in use, such as insufficient resistance to hydrolysis in case of Nylon (for example RYLSAN in D12) or difficulties in respect of manufacturing of the pipe in case of certain fluoroplastics (Teflon in D1).

Furthermore the skilled person was also aware of the fact that PVDF resins had excellent extrudability, heat resistance and chemical resistance and had been used for pipe linings (see the patent in suit, page 2, lines 23 to 25). However, mainly because of its high rigidity and cracking tendency, it was not held suitable for flexible pipes (see page 2, lines 26 to 36 of the patent in suit).

Judged against his background, the introduction on the market of Solef 11010 as the industry's first PVDF based copolymer in the journal in accordance with D2 (see also D3), in which publication particular reference is made to the ease of processing on conventional extrusion equipment, the good flexibility and low notched Izod impact sensitivity unlike the PVDF homopolymers and some other fluoropolymers, while flexibility and elongation remained stable over a period of time at temperatures up to 160 C, no doubt the skilled person would be encouraged to try this new material for the inner pipe of D1, because these improved properties of the new material filled the gap of properties searched for.

5.5. The respondent argued that D2 and D3 concerned publications which restricted the application of Solef 11010 to plenum wire and cable jacketing, which was an application very remote from the use in flexible composite pipes for transport of oil and gas from a submarine oil field. It was not self-evident that materials used for cable jacketing would be suitable for forming the inner pipe of a composite flexible conduit.

Although D2 (and also D3) refers to the use of Solef 11010 primarily for plenum wire and cable jacketing such a disclosure cannot be considered as an intended or suggested limitation for other uses. Evidently, in view of the apparent economic importance of cable manufacturing such possible use is highlighted when introducing a new material, however, without any suggestion to the skilled person to exclude other applications.

5.6. It cannot be accepted either that the skilled person would not consult technical journals of more general kind such as D2 and D3, merely because the flexible composite pipes for submarine use in accordance with the patent was a highly specialised technical field, another argument relied upon by the respondent. On the contrary, a skilled person looking for suggestions in respect of avoiding shortcomings encountered with known materials is to be expected to search on a large available scale for better materials coming on the market.

In view of the range of properties which clearly make the known PVDF polymers particularly suitable for use as pipe lining and the known shortcomings in respect of flexibility and crack propagation, any further development of this known material certainly would merit the attention of the skilled person if these shortcomings were said to be overcome, irrespective of other uses of the material if these uses are not in disagreement with the use of the material as an inner pipe lining. Moreover, the manufacture of pipe linings and linings of cables are both linked to similar extrusion processing, another important parameter referred to in D2 as an improved property of the new material: no special processing equipment is required because of the lower extrusion temperatures, contrary to the extrusion conditions of many conventional fluoropolymer resins.

Since as outlined above, the skilled person was informed by D2, in addition to the known range of properties necessary for the intended use, with the wanted additional properties in respect of flexibility, improved Izod impact sensitivity, thermal stability and ease of manufacture, so that the selection of Solef 11010 as a material for the inner pipe of the composite pipe in accordance with the pipe known from D1 must be considered obvious to the skilled person.

5.7. The respondent also argued that one of the most important characteristics of the material to be selected was its high melting point. It was submitted that in view of the relatively low melting point alone, the skilled person would in fact have been prejudiced against the use of the Solef- and Kynar-type products for forming an inner tube for transporting high-temperature fluid.

In this respect the Board is of the opinion that the skilled person is not led by the melting temperature of the material alone but rather by the thermal stability of the material at the working temperature. In view of the fact that D2 discloses an thermal stability of up to about 160°C (320°F) of the PVDF copolymer Solef 11010, there is no reason for the alleged prejudice in that Solef 11010 would not be suitable as an inner pipe material for use at temperatures exceeding 100 C.

5.8. Since the obvious exchange of the fluoroplastics used for the inner pipe of the flexible composite pipe known from D1 by the fluoroplastic Solef 11010 immediately leads to the use in accordance with the present claim 1, the subject-matter of this claim lacks an inventive step within the meaning of Article 56 EPC. For this reason claim 1 is not acceptable and as a consequence the respondent's request must fail.