Friday, 6 May 2011

T 1171/08 – On Purpose

In the present case the opponent filed an appeal against the decision of the Opposition Division to maintain the opposed patent in amended form.

The Board spots an A 123(2) problem:

*** Translated from the German ***

[1] The claims as filed concerned, on the one hand, a process for removing COS and other acid gases from a hydrocarbonaceous fluid stream containing CO2, COS and, as the case may be, other acidic gases as impurities (claim 1), and, on the other hand, a scrubbing liquor for removing of COS from hydrocarbonaceous fluid stream containing COS (claim 9).

The process was characterised in that the fluid stream is brought in intimate contact with a scrubbing liquor consisting in an aqueous amine solution containing from 1.5 to 5 mol/l of an aliphatic alkanolamine of from 2 to 12 carbon atoms and from 0.4 to 1.7 mol/l of a primary or secondary amine as activator, in that COS is essentially completely removed from the fluid stream and in that the substantially decontaminated fluid stream and the COS-loaded scrubbing liquor are separated and discharged from the absorption or extraction zone.

Product claim 9 was characterised by its specific composition, i.e. an aqueous amine solution containing from 1.5 to 5 mol/l of an aliphatic tertiary alkanolamine and from 0.8 to 1.7 mol/l, preferably from 0.8 to 1.2 mol/l, of a saturated 5- or 6-membered N-heterocycle used as activator, which optionally contains further heteroatoms selected from oxygen and nitrogen.

Claim 1 before the Board is directed to the use of a scrubbing liquor consisting of an aqueous amine solution for selective removal of COS with respect to CO2, from fluid streams comprising CO2, COS and, as the case may be, further acidic gases. The scrubbing liquor that is used comprises from 1.5 to 5 mol/l of an aliphatic tertiary alkanolamine of up to 12 carbon atoms and from 0.8 to 1.7 mol/l of an activator selected from piperazine, methylpiperazine and morpholine.

[2] Thus the scrubbing liquor that is used in claim 1 is not necessarily identical with the one defined in claims 1 and 9 as filed. Also, the scrubbing liquors according to claim 1 and 9 as filed can differ with respect to each other.

[3] According to the established case law of the Boards of appeal (see also “Case Law of the Boards of appeal”, 6th edition, 2010, Chapter III.A.7) the relevant question for the allowability of amendments is whether the proposed amendments are directly and unambiguously derivable from the application as filed.

[4] The [patent proprietor] is of the opinion that there cannot be an unallowable extension, be it only because all the conditions for reaching the selective removal of COS are implicitly contained in the claim via the indication of purpose (Zweckbestimmung).

[5] The indication of purpose as a functional feature in a use claim limits the claim to the embodiments wherein the purpose is achieved. It is only in this respect (insofern) that the indication of purpose can implicitly comprise features that are required for achieving the desired purpose. However, it cannot possibly serve to replace the essential features that are concretely disclosed in combination in an application. If this were the case, then there would be no need to identify the essential ingredients of the scrubbing liquor and their concentration in claim 1 under consideration. However, this would clearly lead to an extension with respect to the content of the application as filed because the latter only discloses scrubbing liquors which necessarily contain certain quantities of concrete aliphatic alkanolamines and concrete primary or secondary amines as activators.

As a consequence, as far as A 123(2) is concerned, it is necessary to determine which features can be directly and unambiguously derived, in the context of the purpose of use, from the application as filed in the present case. […]

The Board finally came to the conclusion that claim 1 did not comply with the requirements of A 123(2) and revoked the patent.

To read the whole decision (in German), click here.

The file wrapper can be found here.