T 1559/05 15-11-2007

I. European patent No. 0 797 088 (based on application No. 97301686.8) was revoked by the decision of the opposition division dated 21 October 2005.

II. On 21 December 2005 the patent proprietor filed an appeal against this decision and paid the appeal fee on the same day. In the statement setting out the grounds of appeal received on 28 February 2006 the appellant requested that the decision of the opposition division be set aside and that the patent be maintained on the basis of the set of claims of the new main request filed therewith or, as auxiliary request, that oral proceedings be arranged.

III. In its reply received on 3 July 2006 the respondent requested that the appeal be dismissed and also, as auxiliary request, oral proceedings.

IV. In a summons pursuant to Rule 71(1) EPC sent on 26 June 2007 the board invited the parties to oral proceedings to take place on 15 November 2007.

V. In a letter dated 22 October 2007 and filed by facsimile on the same day the appellant stated that it would not attend the oral proceedings. Furthermore it was maintained that the appeal should be allowed for the reasons set out in the statement of grounds of appeal and that its new main request should be remitted to the opposition division for further consideration in relation to Article 56 EPC.

VI. In a letter dated 5 November 2007 and received by facsimile on the same day the respondent announced that it would not attend the oral proceedings.

VII. The wording of claim 1 reads as follows:

"A microplate for use in assaying samples, comprising:

a frame that forms sidewalls of at least one well; and

a first layer that forms a bottom of the at least one well, the first layer being formed from a plastic material having an average optical density that is no more than approximately 0.09 at a thickness of approximately 7.5 mils between wavelengths of approximately 200 nm and approximately 300 nm, with the proviso that said plastic material is not TPX® 4-methylpentene-1 polymer from Mitsui Petrochemical Industries, Japan".

Claims 2 to 20 are dependent claims.

VIII. The arguments of the appellant may be summarised as follows:

Claim 1 of the new main request is based upon claim 1 of the first auxiliary request considered by the opposition division during oral proceedings, which included the proviso that: "said plastic material is not 4-methylpentene-1 polymer". By means of this disclaimer the applicant sought to distinguish the present invention from the disclosure in US-A-5,487,872 (document D2) which had been acknowledged in paragraph [0007] of the patent specification. According to the opposition division the disclaiming of any 4-methylpentene-1 polymer material was not specifically disclosed in the application as originally filed and was therefore objectionable under Art. 123(2) EPC because it did not comply with any of the conditions set out in Enlarged Board of Appeal Decision G 1/03, namely, document D2 did not form part of the state of the art under Article 54(3) and (4) EPC and was not an accidental anticipation, nor was the disclaimer's subject-matter excluded from patentability for non-technical reasons. For this reason claim 1 of the present main request differs from claim 1 of the first auxiliary request considered by the opposition division insofar as the proviso now requires that: "said plastic material is not TPX® 4-methylpentene-1 polymer from Mitsui Petrochemical Industries, Japan". The basis for this expression is found in paragraph [0007] of the granted patent specification where it is stated that:

"U.S. Patent No. 5,487,872 to Hafeman el al. (Hafeman) discloses a microplate designed for assaying samples with UV absorption techniques. Hafeman discloses a variety of materials from which the bottom surface of the microplate wells may be formed, including TPX® 4-methylpentene-1 polymer as the preferred material (Mitsui Petrochemical Industries, Japan). However, it is believed that microplates using this material for the well bottom may have limited sensitivity in certain biochemical experiments. For example, in nucleic acid studies, UV absorption in a range between approximately 260 nm to approximately 280 nm is studied, but TPX® has a relatively high optical density in this wavelength range".

It is the appellant's submission that the disclaimer in claim 1 of its new main request overcomes the deficiencies noted by the opposition division, insofar as it is now relates solely to the material disclosed in paragraph [0007] of the patent. In particular, the disclaimer in claim 1 of its new main request now requires that: "said plastic material is not TPX® 4-methylpentene-1 polymer from Mitsui Petrochemical Industries, Japan". Since the wording of the disclaimer in claim 1 is closely based upon paragraph [0007] of the patent, it is contended that such an amendment fully complies with the requirements of Article 123(2) EPC. Moreover, since the basis for the amendment to claim 1 was disclosed in the application as filed, it is not an "undisclosed disclaimer" and, accordingly, Enlarged Board of Appeal Decision G 1/03 is not relevant.

IX. The arguments of the respondent may be summarised as follows:

The amendment in claim 1 that the "...plastic material is not TPX® 4-methylpentene-1 polymer from Mitsui Petrochemical Industries, Japan" does not have a basis in the original application documents: rather, according to page 3, first paragraph of the original description, any plastics material having the required optical density in the wavelength range of 200 nm to 300 nm may be used in fabricating the microplates. On page 6, lines 16 to 24, numerous examples of suitable materials are listed which can be used in the invention, amongst which are polymethylpentenes (line 20). Now TPX® 4-methylpentene-1 polymer from Mitsui Petrochemical Industries is a polymethylpentene material. Therefore the original application documents disclose exactly the contrary of the appellant's assertion, since polymethylpentenes are explicitly disclosed as being a material suitable for use in the invention. It follows that the original application documents do not disclose at all that the disclaimer now introduced in claim 1 would not have been included in the invention as originally disclosed; therefore this disclaimer does not have a basis in the original application documents. With respect to the appellant's reference to paragraph [0007] of the patent specification, it is noted that this passage merely represents an acknowledgement of the prior art document D2. As a rule such a discussion is not to be seen as a disclosure of the technical teaching of the invention. In particular in this paragraph it is only discussed that microplates made of TPX® material might have limited sensitivity in certain biochemical experiments, for instance in the wavelength range 260 nm to 280 nm where it has a relatively high optical density. However, from this it cannot be inferred that TPX® 4-methylpentene-1 polymer from Mitsui Petrochemical Industries, Japan is to be excluded from protection, since neither the original application documents nor present claim 1 relate to a microplate for which only the UV-absorption range between 260 nm and 280 nm is relevant. Rather, claim 1 relates to microplates of which the bottom wells are made of a material which should have a certain average optical density in the range of 200 nm to 300 nm. As a matter of course TPX® material shows this optical thickness as an average value for the wavelength range 200 nm to 300 nm, even if it might have some relatively higher optical density for the sub-interval 260 nm to 280 nm. Furthermore on page 2, last para of the original description (paragraph [0009] of the patent specification) it is clearly stated that the underlying technical problem was to provide microplates that are relatively inexpensive, comparatively durable and include bottoms having an acceptable optical density across the entire useful range of the UV spectrum, i.e. between 200 nm and 300 nm. The skilled person would undoubtedly consider the use of TPX® material for solving this technical problem, in particular since polymethylpentenes are disclosed as examples of UV permeable materials "suitable for use in the present invention" (page 6, lines 16 to 20 of the original description). Therefore the amendment in claim 1 is a disclaimer which is not disclosed in the application as filed.

For such an undisclosed disclaimer the criteria laid down in the Decision G 1/03 apply. According to Headnote II.3 and the Reasons of this Decision a disclaimer which is or becomes relevant for the assessment of inventive step adds subject-matter contrary to Article 123(2) EPC. In its statement of grounds of appeal, pages 7 and 8, the appellant has explained that this disclaimer had been introduced in order to establish novelty over the disclosure of D2. On page 9 of the grounds of appeal under the heading "Article 56 EPC", D2 is discussed as being relevant for the question of inventive step. On page 13, line 6 of this letter the appellant acknowledges that document D2 is considered as the closest prior art for the issue of inventive step. This is in accordance with the views of the opposition division in its communications of 19 January 2004 and 9 March 2006 and with the respondent's prior submissions in which it was argued that document D2 alone renders the teaching of the patent obvious.

The respondent concluded that the disclaimer does not meet the criteria for allowability set out in Decision G 1/03 and is therefore objectionable under Article 123(2) EPC. Accordingly, the appeal should be dismissed.