Monday, 27 December 2010

T 814/08 – Don’t Look Behind The Fence

Some time ago, we have seen a case where a patentee tried to argue that the allegedly novelty destroying document was not enabling – without success. The present decision shows a case where this argument proved successful.

Claim 11 as maintained by the Opposition Division (OD) read:
11. A boron containing ceramic-aluminum metal composite having a density of at least 95 percent of theoretical density and being comprised of at least 60 percent by volume aluminum metal or alloy thereof, with the boron containing ceramic and at least one reaction product of the boron containing ceramic and aluminum dispersed within the aluminum metal or alloy thereof, wherein the amount of boron containing ceramic is at least 50 percent by volume of the total amount of boron containing ceramic and reaction product present in the composite.
[2.1] The [opponent] cited document D5 (“the Lucas paper”) as novelty-destroying for the subject-matter of product claim 11.

[2.1.1] D5 concerns the matrix microstructure and interfacial precipitation of Al-7Si metal matrix composites (MMCs) containing B4C and SiC particulates processed by a stircast technique […]. One of the MMCs under investigation comprised 25 vol.-% of B4C as a particulate material and an Al matrix alloy A 356 containing 7 wt-% Si and minor amounts of Mg, Ti and Fe […].This composite material was supplied by Dural Aluminium Composites Corporation, La Jolla, Ca., USA, in bar form. D5 […] states:
“Details of the casting technique are considered proprietary by the manufacturer, but the basic processing steps include surface preparation of the reinforcement and then combining the reinforcement with the matrix by stir casting which facilitates suspension of the reinforcement in the molten metal. In all cases, the cast composites were hot isostatically pressed to reduce casting porosity.”
The microstructure of the Al-B4C-MMCs is shown in the micrographs of Figure 2 on page 224 and reveals extensive reaction of the Al alloy matrix on and near the B4C interface, extending approximately 5 μm inward from the particulate surface.

The typical reaction products of B4C reinforcement and aluminium are reported to be AlB and Al4C3 […].

In his second affidavit Dr Chen subjected three of the micrographs of the Lucas paper to image analysing by high resolution digitising, handtracing of the various phases identified and software calculating the surface areas. He finds a value of 56% of the total B4C content of the composite of Figure 2a […]. In his first affidavit, Dr Chen estimated the porosity of the composite after densification by hot pressing to be between 1% and 2%, or, in other words, the density of the hot pressed material of Lucas as 98% to 99% of theoretical density.

Dr Chen finally states:
“While I appreciate that on the one hand the Patentee describes in European Patent No. 1425254 only the production of composite form metal powder using an infiltration technique whilst on the other hand Lucas describes in his paper only the production of composites by stir-casting, it is my opinion that both of these production techniques could result in composite material which is very similar, if not identical. Indeed, just looking at the micrographs of the Lucas paper, I could not say by which method the illustrated composites were formed.”
Dr Chen concludes that at least some of the composite material of the Lucas paper would fall within what the patentee defined in the opposed patent as novel material.

[2.1.2] In the board’s view, these arguments are neither convincing as such nor sufficient to deny novelty of the subject-matter of claim 11.

Firstly, D5 does not reveal the claim feature according to which “the amount of boron containing ceramic is at least 50 percent by volume of the total amount of boron containing ceramic and reaction product present in the composite.”

Secondly, Dr Chen’s assumption of a theoretical density of 98 to 99% is a mere estimation which is not supported by a corresponding disclosure in D5, but apparently based on data obtained from hot pressing of Al castings […]. The board doubts whether results obtained from HIP experiments of a cast Al alloy IN738 can be readily transferred to composites containing a substantial amount of ceramic, such as boron carbide.

Lastly, and most importantly, the board is of the opinion that D5 in itself is not an enabling disclosure of a preparation method for the Al-B4C MMCs under investigation, because the paper clearly states that the process of manufacture is proprietary (i.e. kept secret by the supplier of the MMCs) and involves undisclosed process steps such as surface preparation of the reinforcement, the processing temperatures, and the details of the stir casting which were not part of the skilled person’s common knowledge at the relevant time of the opposed patent.

It is mere speculation when Dr Chen in his first affidavit […] tries to fill the disclosure gaps of D5 as regards the method of producing the MMCs by referring to the so-called Duralcan process (D6, published in 1988). Although D6 does disclose a stir casting process for making Al MMCs, nothing in D5 indicates with the required certainty that the process described in D6 had indeed been used by Dural Aluminium Composites Corporation in the production of the composite material supplied to Lucas and co-workers.

[2.1.3] The [opponent] cited T 77/87
“as making clear that where in a single document relied on there is an inconsistency or lack of teaching, then it [was] legitimate to look behind the document to another document or relevant teaching in order to understand properly the disclosure of that document.”
The [opponent] argued that a person skilled in the art in 2001 reading D5 and faced with a “stir casting” technique that was described in 1991 as proprietary would have no difficulty in selecting the Duralcan process and thus be equipped readily to reproduce the teaching of D5.

The board cannot accept this argument, for the following reasons.

Decision T 77/87 [4.1.6] states:
“Summarising, the inconsistency between abstract document (7) and its basic original document (7’) would lead the man skilled in the art to ignore the abstract as erroneous and to consider as relevant teaching only the description according to the basic document”.
Thus T 77/87 refers to an inconsistency (an obvious error, a technical impossibility) in a document and how it is resolved by the skilled person. It does not deal with a situation where essential information is missing or deliberately withheld, as in the present case.

In the case of D5 there is no error or technical impossibility which could or should be resolved by referring to some related basic document.

[2.1.4] According to T 1437/07 [25], a
“disclosure in a prior art document is novelty-destroying only if the teaching it contains is reproducible. This need for an enabling disclosure is in conformity with the principle expressed in A 83. Thus, the requirements of sufficiency of disclosure are identical for a prior art document and a patent.”
As pointed out above, the Lucas paper does not enable a person of ordinary skill in the art to produce the MMCs under investigation. It is also not clear and proven beyond reasonable doubt that the composite material supplied by Dural Aluminium Composites Corporation, La Jolla, Ca., USA, was made by the Duralcan process disclosed in D6.

[2.1.5] The board therefore concludes that D5 does not anticipate the subject-matter of claim 11.

Should you wish to download the whole document, just click here.

To have a look at the file wrapper, click here

NB: This decision has already been reported on Le blog du droit européen des brevets.