T 2350/11 15-11-2013

Reasons for the Decision

1. The appeal is admissible.

Main request and auxiliary requests 1 and 2

2. Clarity (Article 84 EPC)

2.1 Article 84 EPC in combination with Rule 43(1) EPC requires that the claims must be clear and define the matter for which protection is sought in terms of the technical features of the invention. These requirements serve the purpose of ensuring that the public is not left in any doubt as to which subject-matter is covered by a claim and which not. Accordingly, a claim cannot be considered clear in the sense of Article 84 EPC if it does not unambiguously allow this distinction to be made (see decisions G 2/88, OJ EPO 1990, 93, point 2.5 of the reasons and T 337/95, OJ EPO 1996, 628, points 2.1 to 2.5 of the reasons). A claim comprising an unclear technical feature, therefore, entails doubts as to the subject-matter covered by that claim. This applies all the more if the unclear feature is essential with respect to the invention in the sense that it is intended to delimit the subject-matter claimed from the prior art, thereby giving rise to uncertainty as to whether or not the subject-matter claimed is anticipated (see decision T 560/09, not published, point 2 of the reasons).

2.2 Claim 1 of the main request is directed to the preparation of a perylene pigment product having a clean transparent yellowish shade by comminuting two crude perylene pigment starting materials, each of which is characterised by a general production method (methods 1 and 2, see point IV above). According to the established jurisprudence of the boards of appeal, a product that is characterised by its mode of production has to be interpreted in an absolute sense, that is independently of its production (T 20/94, not published, headnote 2). This applies independently of whether the mode of production is used to characterise a product per se or whether it characterises a product used as starting material in a process. Hence, claim 1 of the main request is directed to the manufacturing of a pigment product using two crude perylene pigment starting materials that can be obtained by the processes referred to in claim 1 (i.e. methods 1 and 2), without their preparation being limited to those processes.

Since the chemical structure of the crude perylene pigment starting materials is identical and since the processes referred to in claim 1 are not considered to be limiting features, it is not possible to clearly identify and distinguish between the perylene pigment starting materials. The use of different starting materials is, however, essential to the present invention. This was also confirmed by the appellant.

2.3 According to the appellant, the perylene pigment starting materials were clearly defined by the different methods for their preparation. The products of the respective methods had different physical properties and it was virtually impossible that the two perylene pigment starting materials were identical. In support, the appellant referred to pages 7 to 8 of document (2) describing a red-brown perylene pigment prepared according to method 2, and to column 3, line 62 to 63 of document (1) disclosing a brilliant red pigment obtained according to method 1. The appellant argued that their outward appearance already showed that these pigments were different products. The person skilled in the art would have no difficulty in objectively distinguishing between these perylene pigments, despite the fact that there was a certain subjective element in colour perception.

As further evidence for the fact that both perylene pigment starting materials were different, the appellant referred to examples 2 and 3 in the table on page 9 of the patent application. In example 2 a pigment prepared according to method 2 and in example 3 a pigment prepared according to method 1 was used. The third column of this table showed different transparency ratios for the respective examples, indicating different physical properties for the two perylene starting materials.

The appellant also argued that, in the absence of evidence to the contrary, there was no reason to doubt that the different processes referred to in claim 1 resulted in different perylene pigment starting materials.

2.4 The appellant's arguments are not considered convincing for the following reasons:

2.4.1 The perylene pigments in documents (1) and (2), relied on by the appellant, are the result of the specific reaction conditions used therein. According to document (1), the brilliant red pigment is the result of a two-step process using a 4-fold molar excess of methylamine at a temperature below 30**(o)C, then heating to 70**(o)C to 150**(o)C (claim 1 and column 3, lines 62 to 63). In example 1 on pages 7 and 8 of document (2) the red-brown filter cake is prepared by mixing perylene-3,4,9,10-tetracarboxylic acid diimide with water, sodium hydroxide and lauryl-trimethylammonium chloride (a surfactant the addition of which belongs to the inventive concept of document (2)) followed by the addition of methylene chloride, heating to 100**(o)C, keeping at this temperature for 6 hours, pouring into a diluent, adapting the pH and drying. None of these reaction conditions is present in claim 1, which merely indicates the general method for the preparation of the perylene pigment starting materials, that is methylation of perylene tetracarboxylic imide with an alkylating agent and amidation of perylene tetracarboxylic anhydride with methylamine.

The board does not wish to deny that the skilled person may be able to distinguish the perylene pigment prepared under the specific conditions disclosed in document (1) from one prepared according to the method described on pages 7 and 8 of document (2). However, claim 1 is not limited to these particular perylene pigments, by merely referring to the same reaction type and the same starting materials as those used in documents (1) and (2). In this context, the board notes that it is an undisputable fact and well-known to the skilled person that chemical reactions only rarely produce a uniform product. For an unambiguous definition of a particular product it is therefore necessary to provide not only the starting materials (in the present case perylene tetracarboxylic imide and alkylating agent or perylene tetracarboxylic anhydride and methylamine) but also the reaction conditions, the processing of the reaction mixture, the isolation of the product, etc.

The board also notes that the only given characteristic which distinguishes the perylene pigments prepared according to documents (1) and (2) is their colour (brilliant red and red-brown). Since the latter is the result of the specific reaction conditions, the question how to clearly distinguish between perylene pigments which are not brilliant red and those which are red-brown cannot be answered. In this context, the board notes that colour perception is highly subjective and that the application does not contain a method enabling the colour to be objectively measured.

In summary, the specific processes of documents (1) and (2) resulting in perylene pigments with specific properties cannot be relied on as evidence that the perylene pigments referred to in claim 1 are clearly distinguishable.

2.4.2 Similar reasons apply with respect to examples 2 and 3 of the patent application. The board notes that there is no information available as to how these perylene pigments were produced, apart that is from the indication that they were obtained according to general methods 1 and 2 of claim 1. However, there can be no doubt that in order to carry out these general methods, particular reaction conditions and processing steps had to be selected. The measured transparency values, similar to the colour characteristics mentioned in point 2.4.1 above, are therefore the result of those unknown conditions. These examples cannot therefore be relied on as evidence for the fact that perylene pigments produced according to general methods 1 and 2 can always be clearly and unambiguously distinguished by this parameter.

2.5 For the reasons set out above, the board concludes that the perylene pigment starting materials are not clearly and unambiguously defined by the general methods referred to in claim 1. This leaves the public in doubt as to which subject-matter is covered by this claim and which not, with the consequence that the requirement of Article 84 EPC is not met.

2.6 Claims 1 of auxiliary requests 1 and 2 differ from claim 1 of the main request only insofar as the feature "having a clear transparent yellowish shade" for the perylene pigment product has been deleted (see point IV above). This amendment has no influence on the definition of the perylene pigment starting materials. Thus, the same considerations and conclusion as in points 2.1 to 2.5 apply. Consequently, these requests must also be refused for contravening Article 84 EPC.

Auxiliary requests 3 to 6

3. Amendments (Article 123(2) EPC)

3.1 Claim 1 of auxiliary request 3 was amended by the addition of a number of features (particle size, temperature, solvent, molar ratio of reactant, etc.; see point VI above) concerning the reaction conditions of methods 1 and 2. None of these features is disclosed in the application as filed.

3.2 This was not disputed by the appellant, who argued rather that these amendments were disclosed by explicit reference to documents (1) and (3) directed to methods 1 and 2. In support of its view the appellant referred to decision T 6/84, which stated in point 2 of the reasons "that structural features of a means for performing a chemical process which are not mentioned in the application documents themselves but in a document to which they refer may be incorporated into a patent claim if they unequivocally form part of the invention for which protection is sought."

3.3 The description of the application as originally filed indicates, on page 1, three general methods for the preparation of perylene 3,4,9,10 tetracarboxylic acid N,N' bis-methylimide pigments: the reaction of a perylene dianhydride with methylamine (method 1), methylation of perylene diimide (method 2), and fusing naphthalic acid N-methylimide with an alkali hydroxide (method 3) (see page 1, lines 8 to 14 and 19 to 22). In this context, the description also mentions three documents, including documents (1) and (3), as examples of those methods (see page 1, lines 10 to 11 and line 19 to 20), indicating potential ways of preparing the starting materials of the presently claimed method. No reference to particular parts of the documents is made and there is no indication that specific features disclosed in documents (1) and (3) would have to be considered as part of the original disclosure. There is also no indication anywhere in the application as filed that a particular way of realising method 1 or 2 was critical for the invention. In the examples it is merely stated that the perylene pigment starting materials were produced according to general methods 1 and 2 (page 8, line 16 to 21 and page 9, line 8). In these context, no reference is made to documents (1) and (3) and the fact that these documents are referred to in general terms on page 1 of the application as filed is not tantamount to a clear and unambiguous disclosure for the incorporation of any feature disclosed in these documents. Hence, contrary to decision T 6/84, in the present case the features disclosed in documents (1) and (3) are not considered to unequivocally form part of the invention for which protection is sought.

3.4 For the aforementioned reasons, the board concludes that claim 1 of auxiliary request 3 does not comply with Article 123(2) EPC.

3.5 The same amendments as for claim 1 of auxiliary request 3 have been made for claim 1 of auxiliary requests 4 to 6 (see point VI above). Thus, the same considerations and conclusion as in points 3.3 and 3.4 above apply. Consequently, these requests must also be refused for contravening Article 123(2) EPC.

Auxiliary requests 7 and 8

4. Admission into the proceedings

4.1 Auxiliary requests 7 and 8 were filed at a very late stage in the proceedings, namely at the end of the oral proceedings.

4.2 According to the Rules of Procedure of the Boards of Appeal (RPBA), appeal proceedings in ex parte cases are based on the statement of grounds of appeal (Rule 12(1) RPBA). New submissions (requests, facts or evidence) are not entirely precluded; their admission, however, is at the discretion of the boards (Article 114(2) EPC and Article 13(1) RPBA). This discretion has to be exercised appropriately, requiring the boards to consider all relevant factors, taking into account the specific circumstances of the case. Examples of criteria to be taken into consideration by the boards when exercising their discretion are inter alia the complexity of the new subject-matter submitted, the current state of the proceedings and the need for procedural economy. These criteria are not exhaustive, and the boards have also considered aspects such as the reasons for the new submission or the extent of the amendments.

4.3 The appellant justified the late filing of auxiliary requests 7 and 8 as being a direct reaction to the discussion that took place during oral proceedings and an attempt to overcome the board's objections under Article 84 EPC.

4.4 However, the issues related to Article 84 EPC were already pointed out to the appellant in the board's communication accompanying the summons to oral proceedings. No additional objections under this article were raised during those proceedings. The board also fails to see - and the appellant did not provide -any convincing reasons why the appellant could not have filed requests 7 and 8 together with its reply to the board's communication. Accordingly, the board sees no justification for the late filing of auxiliary requests 7 and 8.

Furthermore, it is not immediately apparent that the additional feature or features in auxiliary requests 7 and 8 are suitable to overcome the board's objections without at the same time giving rise to new clarity issues, in particular in view of the fact that the appellant attempts to improve the clarity of claim 1 by including a compound designated by a trade mark. With such a designation there can be no certainty that the compound remains unaltered throughout the life of the patent.

4.5 For the aforementioned reasons, the board decided not to admit auxiliary requests 7 and 8 into the appeal proceedings (Article 114(2) EPC and Article 13 RPBA).