T 79/08 – When Rods Spoil ... The Patent

This decision deals with an appeal of the patent proprietor after the Opposition Division (OD) had revoked its patent for lack of inventive step.

Claim 1 of the main request before the Board read:

A dispersion comprising non-melt-processible fluoropolymer particles having an SSG of less than about 2.225 in aqueous medium, said fluoropolymer particles comprising a core of high molecular weight polytetrafluoroethylene and a shell of lower molecular weight polytetrafluoroethylene or modified polytetrafluoroethylene, wherein at least about 1.5 weight % to about 20 weight % of said fluoropolymer particles comprise substantially rod-shaped particles having a length to diameter ratio of greater than about 5.

The Board discusses sufficiency of disclosure:

General considerations

[3.1] It is disputed between the parties whether the feature relating to the content of rod-shaped particles was sufficiently disclosed.

[3.2] It is helpful to recall the development of the relevant arguments:

[3.2.1] During the proceedings before the OD and in the initial stages of the procedure before the Board this dispute focussed on the question of analysing the diagrams in order to count and measure the particles […].

[3.2.2] However in the latter stages, commencing with the submission of the Poggio affidavit the question of the calculations performed on the data retrieved from the counting was raised […].

[3.3] The guiding principle in the large body of case law developed with respect to A 83 EPC is that the skilled person should, after reading the description be able readily to perform the invention over the whole area claimed without undue burden and without needing inventive skill (cf. T 694/92 [5, final section].

[3.4] Accordingly in a first step it is necessary to examine whether the teaching of the patent in suit provides a disclosure of all relevant aspects relating to the determination of the content, expressed as weight %, of rod-shaped particles.

The amount of rod shaped particles - disclosure in the patent in suit

[4.1] According to […] the patent in suit the content of rod-shaped particles is determined as follows:

• Dispersions are prepared on substrates and images are obtained by scanning electron microscope;
• The images are visually inspected;
• Particles are hand counted;
• Counted particles are modelled as cylinders whose height is the long axis and whose diameter is the short axis;
• Particle dimensions are measured with a ruler in mm and converted to nm using the scale given on the SEM image.

This passage thus teaches only how to obtain the images and how to retrieve the data relating to particle dimensions form the images. There is no teaching here regarding the calculations to be performed on the data.

[4.2] In example 1 it is disclosed in relation to the determination of the content of rods […]:

• Typical particle shape is cylindrical with rounded ends;
• A hand count of 230 particles gave a distribution of long and short axis (depicted graphically in figure 4 of the patent in suit):

• Those particles having a ratio of long axis to short axis of greater than 5 comprised 10% by number of particles counted;
• Modelling these as cylinders gave a weight percent of these particles of 2.8 wt%;
• The rod-shaped particles had average dimensions of 900 nm of length and 68 nm of diameter;
• The average length of all particles was 413 nm and the average diameter was 183 nm (emphases of the Board).

Thus the report of this example provides the following information:

• The total number of particles considered (230)
• The proportion of these having a l/d ratio of greater than 5, i.e. rod-shaped particles;
• The weight proportion of these in these particles is reported (2.8 wt%). This language, in particular the use of “these” indicates that the weight percentage is based on the totality of particles analysed i.e. the 230 particles counted.
• The average length and diameter of the entire population of particles and of the rod-shaped particles.

[4.3] At this stage of the disclosure there is however no explicit statement relating to the calculations carried out in order to obtain the reported figure for weight proportion.

The OD understood from the examples of the patent in suit that the reported averaged values were to be used […]. This finding was not disputed by the patent proprietor either at the oral proceedings (OPs) before the OD or in its statement of grounds of appeal since, according to it submissions at the first OPs before the Board the significance thereof had not been appreciated […]. The Board however notes the diverging statement made in relation to the same issue at the second OPs before the Board at which the patent proprietor submitted that the reason for not raising this matter was that it had been assumed that everyone would realise that the reasoning of the opposition had been wrong […].

[4.4] As shown by submissions made by both parties during the appeal procedure, carrying out this calculation on the data provided in the patent in suit would yield results with varying degrees of agreement with the values reported […]:

− Based on the data given in example 1 a value diverging upwardly from that reported in the patent in suit would be obtained, i.e. 3.0 wt% instead of 2.8 wt% […];

− The data of example 2 would yield the same value as that reported in the patent in suit (1.9 wt%) […];

− Employing the data of example 4 would yield a value of 10.9 wt%, thus diverging downwardly from the value reported in the patent in suit (14.6 wt% […]).

[4.5] The patent in suit provides no prior art references relating to the determination of the weight percentage of particles of a particular morphology in such dispersions. This lack of any pertinent prior art references is consistent with the presentation of the patent in suit and the position of the patent proprietor that the realisation that the content of rod-shaped particles was critical was at the heart of the invention to which the patent in suit relates […].

[4.6] The argument of the patent proprietor […] that the skilled person would understand, on the basis of paragraph [0067] that only the individual method – “Method A” would lead to meaningful results not only fails to take account of the explicit teaching of the examples of the patent in suit which refer to the average values, but also advances no explanation as to why, despite the absence of any explicit reference to the properties of the individual particles in the patent in suit and apparently in direct contradiction to the explicit teaching of the examples in respect of the average values, the skilled person would assume that the individual values were to be used.

[4.7] Accordingly the Board can come to no conclusion other than that, based on the disclosure of the patent in suit itself, there is no sufficient disclosure of the manner in which the content of rod-shaped particles is to be determined.

[4.8] Accordingly the patent in suit cannot provide a basis for recognising sufficiency of disclosure (A 83).

[5] It thus needs to be investigated whether the skilled person, could by other means, e.g. by reference to common general knowledge, arrive at an understanding of how to determine this feature of the claim.

[5.1] As held in T 629/05 [4] in the assessment of sufficiency of disclosure the skilled person may use common general knowledge to supplement information contained in the application and may even recognise and rectify errors in the description on the basis of such knowledge, the central criterion being that it must be possible to reproduce the invention without any inventive effort and undue burden.

[5.2] It appears to be a matter of consensus between the parties that the skilled person would recognise an incoherence, in some cases, in the disclosure of the patent in suit between the reported contents of rod-shaped particles and those which emerge from the data reported relating directly to the properties of the particles (average dimensions).

[5.3] The question to be answered is whether the skilled person would on the basis of general knowledge be in a position to supplement the teaching of the patent in suit and so reconcile this incoherence.

[5.4] As already explained […] above there is no prior art identified in the patent in suit which could provide a basis for such a rectification.

[5.5] Regarding the general knowledge of the skilled person, the only evidence available is that provided by the various statements made during the procedure.

[5.6] The evidence provided by the patent in suit itself is that the inventor was not aware of the significance of the manner of calculating or even of a distinction between different methods. The statement of the patent proprietor at the first OPs is consistent with this […]. Interestingly the patent proprietor appears to have reviewed its position on this by the time of the second OPs […] when it was stated that the reason for not commenting on this was that it had been assumed that the skilled person would realise that the calculation on the basis of the average values was incorrect.

[5.7] According to the expert of the opponent - as reproduced in the Poggio affidavit it seems that it was also not realised prior to the first OPs before the Board that the manner of calculation, i.e. whether the particles were treated individually or collectively was of significance. On the contrary according to Poggio it appears to have been assumed that the two values were interchangeable […].

[5.8] At the first OPs the confusion over this matter was emphasised since the representatives themselves took positions at odds with the statements of their respective experts […] regarding the manner of calculation. This alone constitutes a strong indication that the skilled person would not have known from other sources which method was to be employed.

[5.9] The submissions of the patent proprietor at the second OPs […] that the divergences in the results reported in the patent in suit and those obtainable on the basis of the reported average values would reveal that the individual method, not the collective method was to be used relies on making an assumption for which no evidence has been advanced, namely that there are only two methods of calculation possible.

[5.10] On the contrary there is evidence that the matter is not as clear-cut as implied by the patent proprietor. This evidence is provided on the one hand by the diverging statements made by the patent proprietor with respect to the calculation method set out in the decision under appeal […] and by the Poggio affidavit according to which a hybrid calculation was employed in which the rod-shaped particles were treated individually but the entire population was treated collectively, employing average values.

[5.11] Thus the evidence provided by the submissions of the parties is that these experts were not even necessarily aware that the manner of calculating the content of rod-shaped particles was of significance, let alone that this had to be performed in a highly specific manner.

[5.12] The patent proprietor also argued that the skilled person would not only note that there was a divergence between the reported values for the content of rod-shaped particles and the value that would be obtained based on calculations employing the data reported but would also note that the magnitude of the divergence increased with higher contents of particles, understand the significance of this and thus come to the conclusion that it was necessary to employ the method of treating the particles individually rather than collectively.

Disregarding for the moment that this submission is irreconcilable with the statement made by the patent proprietor at the first OPs held before the Board that the significance of the calculation method as set out in the decision under appeal had not been appreciated […], it is the opinion of the Board that to arrive at such a conclusion, in the absence of any indication of pertinent general knowledge demands of the skilled person, a level of insight and understanding which approaches that required for inventive step. However the pertinent case law emphasises that the same level of skill is to be applied when the questions of sufficiency of disclosure and inventive step are considered (cf. T 60/89 [3.2.5]).

[5.13] Even accepting, for the sake of argument, that such insight would be within the range of normal, non-inventive ability of the skilled person, there remains the obstacle that the patent in suit itself provides no means by which the validity of such an insight could be tested. Raw data is provided only in the nature of images of extremely poor quality. In this connection it is recalled that the images provided by the then opponent during the opposition proceedings […] were considered by the patent proprietor to be of insufficient quality to allow analysis (counting of the particles) notwithstanding that these images appear to be significantly clearer and of higher quality than those contained in the patent in suit.

[5.14] Also complete repetition of the examples of the patent in suit does not provide a route - without undue burden - to clarify this aspect since doing so involves multiple stages, each of which is prone to error and thus any divergence could have one of a number of sources, no means being provided in the teaching of the patent in suit to exclude one or other source of error.

[5.15] Accordingly the patent proprietor has failed to show that the skilled person would be in a position to understand the cause of the varying degree of agreement between the reported values of rod content and those values that would be obtained on the basis of calculations performed on the data provided in the patent in suit, and having done so to rectify this based on either common general knowledge or the data in the patent in suit.

[5.16] Indeed the Board is aware that the entire foregoing section relies on making a key assumption - namely that the skilled person would identify the nature of the calculation as being the source of the divergences. This has in fact been assumed by both parties. However this assumption is in the Board’s view not valid. For example it takes no account of the possibility of alternative sources of error such as clerical errors in the patent in suit, or even errors in collating and analysing the data, e.g. instrumental errors.

[5.17] Thus it has not been shown that the skilled person would necessarily even realise that the calculation method was at the source of the divergences, let alone that the skilled person would be in a position to identify precisely the nature of the problem with the calculation method, how to correct it and, on the basis of the data in the patent in suit, confirm that this was in fact the correct calculation method.

[5.18] On the other hand, it is clear that the promise of the invention (PTFE dispersions of higher CCT) is only accessible via a reliable fulfilment of the crucial condition set out in claim 1, namely that: “at least about 1.5 weight % to about 20 weight % of said fluoropolymer particles comprise substantially rod-shaped particles having a length to diameter ratio of greater than about 5.” which in turn requires the preparation of a dispersion having the correct fraction of substantially rod-shaped particles. However, as shown above, the necessary information to achieve this is absent from the patent in suit.

[6] It is therefore concluded that the patent in suit does not provide sufficient information to allow the skilled person to reproduce the claimed invention. Nor is the skilled person in a position - without undue burden and without inventive effort - to make good this deficit. Accordingly it has to be concluded that the requirements of sufficiency of disclosure are not satisfied.

As the claims of all request rely on the definition of the content of rod-shaped particles, this objection applies to all requests.

Accordingly none of the sets of claims on file meets the requirements of A 83. […]

The appeal is dismissed.

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