T 1414/12 - Omitting reference to process

Key points

• In this opposition case, the independent claim 10 at issue was for a "acidic aqueous conversion coating solution". The claim as granted specified "for a process as claimed in claim 1". The Board finds that deleting this feature extends the scope of protection and violates Article 123(3) EPC.
• In Auxiliary Request 1, the reference to claim 1 was added. The Opponent objected as to added matter, but the Board finds that Article 123(2) EPC is complied with.
• Interestingly, the claims is directed to coating solution, but the Board was chaired by Meinders.

T 1414/12 - link

Summary of Facts and Submissions

VI. The wording of claim 1 of the main request reads as follows (in bold the amendments with respect to claim 10 of the patent as granted; deletions in strikethrough; emphasis added by the Board):

"An acidic aqueous conversion coating solution [deleted: for a process as claimed in claim 1] which is free of hexavalent chromium, comprises a water soluble trivalent chromium compound, a water soluble fluoride compound, and an additive for improved corrosion resistance properties, characterised in that the additive is nitrilotris (methylene) triphosphonic acid (NTMP)."

Reasons for the Decision

1. Main request - allowability of amendments

1.1 Claim 1 of the main request is based on claim 10 of the patent as granted (see point VI above) in which the reference to process claim 1 has been deleted.

The appellant has raised an objection pursuant to Article 123(3) EPC arguing that the deletion of the reference to claim 1 of the patent as granted would result in an extension of the scope of the product claim 10 of the patent as granted.

In that respect it has to be determined whether the process of claim 1 of the patent as granted implies limitations to the product of claim 10 of the patent as granted.

1.2 The Board shares the appellant's view that the product of claim 10 of the patent as granted has to be suitable for performing the process of claim 1 of the patent as granted, i.e. the additive needs to be suitable "to form an Al-O-P covalent bond and subsequent formation of a network of hydrophobic layer over all active corrosion sites".

By the deletion of the reference to the process of claim 1, it is no longer mandatory that the claimed product be suitable for the formation of a network of hydrophobic layer over all active corrosion sites. The scope has therefore been extended to acidic aqueous conversion coating solutions which are not suitable for forming a network of hydrophobic layer over all active corrosion sites.

Hence, contrary to the findings of the opposition division (impugned decision, point 7.3.3) and to the respondent's view put forward at the oral proceedings, the reference to claim 1 imposes a clear limitation onto the product of claim 10 of the patent as granted so that claim 1 of the main request, now without that reference, contravenes Article 123(3) EPC.

1.3 The respondent's arguments that the appellant has not adduced any evidence that there exist conversion coating solutions within the scope of claim 1 of the patent as maintained that would not be suitable for use in a process of claim 1 as granted is not convincing.

As a matter of fact, what matters is whether the composition as claimed would inevitably lead to the formation of a network of hydrophobic layer over all active corrosion sites. This appears, however, not to be the case since there is no basis to be found in the contested patent for such a conclusion.

1.4 Contrary to the respondent's view, the Board is of the opinion that the feature of the process claim 1 of the patent as granted of a "subsequent formation of a network of hydrophobic layer over all active corrosion sites" has a clear technical meaning for the skilled person in the present technical field. Indeed, he knows the technical effect(s) of a hydrophobic layer. Thus, such a technical feature cannot be deleted (by the deletion of the reference to process claim 1 of the patent as granted) without contravening Article 123(3) EPC (Case Law of the Boards of Appeal, 8th Edition 2016, II.E.3.1 and 3.2; G 1/93, OJ EPO 1994, 541, points 13 and 16 of the reasons). As the features at stake are technically significant the decision T 518/99 (not published in OJ EPO, point 4.5.2 of the reasons) cited by the respondent at the oral proceedings does not apply.

1.5 The Board shares the respondent's view that product claim 10 of the patent as granted is indeed an independent claim. In that respect, however, the reference to process claim 1 is an essential feature of the claimed product. The fact that product claim 10 of the patent as granted is an independent claim does not, however, allow to leave out of consideration the limitations implied by the reference to the process of claim 1, as discussed under point 1.2 above.

1.6 The respondent's argument that claim 1 of the main request would be equivalent in scope to claim 2 of the application as filed relates to the fulfilment of the requirements of Article 123(2) EPC, not to those of Article 123(3) EPC. Hence, it cannot be convincing in that respect.

This also applies to the reasons brought up for assessing novelty and inventive step of the claimed subject-matter of the patent as granted which relate to the fulfilment of the requirements of Articles 54(1) and 56 EPC in the examination procedure.

1.7 At the oral proceedings, the Board made clear that, due to the wording "comprises" used in the claim, the claimed conversion coating solution is open to any additional compounds, including compounds with technical effects adverse to those sought of forming an Al-O-P covalent bond and a network of hydrophobic layer. Therefore, claim 1 of the main request encompasses conversion coating solutions not necessarily suitable for the process of claim 1 of the patent as granted, i.e. not suitable to achieve the effects claimed therein, contrary to the claimed products of the patent as granted.

As further discussed at the oral proceedings, even a restriction to a specific NTMP content, as defined for instance in claims 2 or 3 of the main request, would not enable to overcome the objection in view of the open composition of the claimed conversion coating solution.