T 0474/17 - Implicit disclosure

 Key points

• In this opposition appeal, the opponent argues that the claim is not novel over Example 22 of E1, a prior art European patent publication. The claim under examination is directed to a cutting tool with a titanium carbonitride layer defined inter alia by certain parameters describing the texture. E1 does not describe the texture. The opponent performed experiments and filed a report repeating Example 22 of E1.
• The Board: “ this sample reproduced by the appellant according to the teaching of E1 fulfils the texture requirements of features M9 and M10 of claim 1 of the patent irrespective of the method used for processing the [electron backscattering diffraction] data. The parameters defined in claim 1 are therefore implicitly disclosed by E1 in line with established case law such as T 1523/07 and T 1085/13 cited by the respondent.”
• As a comment, in my article in epi Information 4/2020, I propose that it may be more precise to say that E1 discloses a product that inherently falls within the ambit of claim 1 because probably an amendment of E1 to add the texture features would involve added subject-matter under Article 123(2).
  
  
• The Board, on when an experiment is a sufficiently close repetition of a prior art example: “The Board agrees with the conclusions presented in the case law cited by the respondent [patentee] that only a true repetition of an example of the prior art can be taken into account for proving that a parameter is implicitly met by an example of the prior art. However, the technical particularities of the specific example, the technical field and the practical implications thereof have to be taken into account. In the present case, the Board concludes that [opponent's] sample 17ELi05-N25M is sufficiently close to example 22 of E1 to prove, that the texture parameters defined in features M9 and M10 of claim 1 are unambiguously fulfilled by said example.”

T 0474/17

https://www.epo.org/law-practice/case-law-appeals/recent/t170474eu1.html

Hence, E1 does not describe which overall texture is obtained for the TiCN layer.

1.2.2 The appellant performed experiments on the basis of the examples of E1 comprising a TiN innermost layer and a TiCN layer having (111)(222)(200) orientation. The results of these experiments are reported in Annexes 1, 2 and 8.

The following reasoning focuses on sample 17ELi05-N25M, which is considered by the Board to represent a fair repetition of example 22 of table 6 of E1.

The sample 17ELi05-N25M produced according to Annex 8 comprises a cemented carbide substrate having the composition 5.35 wt% Co, 2.70 wt% Ta, 0.42 wt% Nb, 1.80 wt% Ti and balance W+C, an innermost TiN layer having a thickness of 0.5 µm and an inner TiCN layer having a thickness of 6.4 µm.

Annex 8 confirms on page 1 in regard to the methods for forming the coatings, that

- the TiN layer was made using the reaction conditions disclosed in Table 3(a) of E1, lines 11 to 13 and

- the TiCN layer was made using the two step reaction conditions disclosed in Table 3(a) of E1, lines 16 to 18.

Processing the EBSD data of the TiCN layer of sample 17ELi05-N25M in "Texture Component" mode, the appellant has demonstrated that the highest peak in the tilt-angle frequency distribution graph is at 7.3° and that the total sum of frequencies existing in the range of 0 to 10° occupies 61.2% (table on page 4 of Annex 8).

Using "Pole Plot" mode for the processing of the EBSD data, the TiCN layer of sample 17ELi05-N25M has the highest peak in the tilt-angle frequency distribution graph at 1.15° whereby the total sum of frequencies existing in the range of 0 to 10° occupies 56.6% (table on page 1 of Annex 9).

Hence, this sample reproduced by the appellant according to the teaching of E1 fulfils the texture requirements of features M9 and M10 of claim 1 of the patent irrespective of the method used for processing the EBSD data.

The parameters defined in claim 1 are therefore implicitly disclosed by E1 in line with established case law such as T 1523/07 and T 1085/13 cited by the respondent.

1.3 The respondent argued that sample 17ELi05-N25M is not an accurate and slavish repetition of a specific example of E1, since

- the composition of the substrate differs,

- the thickness of the TiN and TiCN layers differs,

- it has not been demonstrated that the ratio of the intensities of (111), (200) and (220) peaks in the

XRD spectrum is obtained as required by E1, 

- the sample does not comprise an alumina layer as required by example 22.

Therefore in their opinion the reproduced sample 17ELi05-N25M was not to be taken into account for proving the implicit disclosure of E1 in line with established case law such as T 1236/03, T 909/04, T 885/02, T 437/14.

1.4 The Board agrees with the conclusions presented in the case law cited by the respondent that only a true repetition of an example of the prior art can be taken into account for proving that a parameter is implicitly met by an example of the prior art. However, the technical particularities of the specific example, the technical field and the practical implications thereof have to be taken into account.

In the present case, the Board concludes that sample 17ELi05-N25M is sufficiently close to example 22 of E1 to prove, that the texture parameters defined in features M9 and M10 of claim 1 are unambiguously fulfilled by said example.

1.4.1 The cutting tool according to example 22 comprises a cemented carbide substrate D having the composition 5.2 wt% Co, 2.5 wt% Ta, 1.70 wt% Ti, 0.3 wt% Nb and balance W+C (table 2 on page 12 of E1).

The composition of the substrate D is therefore very close to the composition of the substrate used for sample 17ELi05-N25M comprising 5.35 wt% Co, 2.70 wt% Ta, 1.80 wt% Ti, 0.42 wt% Nb and balance W+C. In terms of practical feasibility to repeat an example of the prior art, it is considered to be a true repetition of E1, since the differences in the composition are marginal. Moreover, taking into account that a further TiN layer is present between the substrate layer and the critical TiCN layer, it is also not credible that the minimal difference in the composition of the substrate has an influence on the texture of the TiCN layer due to a hypothetically possible diffusion of the Co into the subsequent layers.

1.4.2 Also the thickness of the TiN and the TiCN layers of the tool of example 22 of E1 and of sample 17ELi05-N25M differ only by 0.1 µm. These layers are applied by a CVD process where such differences in the coating thickness are unavoidable within normal experimental routines. Moreover, a marginal difference in the thickness cannot be expected to have any impact on the texture of the TiCN layer.

1.4.3 Annex 8 clearly indicates on page 1 that exactly the same coating conditions have been used as in E1 and refers explicitly also to the corresponding text passages in E1. Hence there is no reason to doubt that the texture required by E1 was obtained, since exactly the same CVD conditions, decisive for forming a specific texture, are used as described in E1.

Furthermore, E3 confirms in table II on page 635 that it is possible to achieve a TiCN layer having a (422) texture with the relative intensities of I(111) > I(220) > I(200) as required by E1. E3 therefore confirms that the texture determined for sample 17ELi05-N25M is not contradictory to the teaching of E1, contrary to the argument of the respondent.

1.4.4 Although required according to example 22 of E1, sample 17ELi05-N25M of Annex 8 does not comprise an upper layer of Al2O3 which has kappa as its main form.

However a further coating of Al2O3 does not change the texture of the already formed TiCN layer. A further kappa-Al2O3 coating is therefore not required to demonstrate that the previously formed TiCN layer of example 22 has the texture as defined in claim 1 of the patent.

1.5 In summary, the Board concludes that sample 17ELi05-N25M is a repetition of example 22 of E1 as far as it can be reasonably expected in the technical field of CVD coated cutting tools and credibly demonstrates that features M9 and M10 of claim 1 are implicitly met by example 22.

The ground of opposition pursuant to Article 100(a) EPC in combination with Article 54 EPC therefore prejudices the maintenance of the patent.