T 0128/82 - Inventive step of product claims

Key points

This is a decision from the archives.
Let's assume a patent with a single claim directed to a single compound X. The claim is a pure compound claim, simply reciting the chemical formula (or IUPAC name), nothing more. The description teaches one possible use of compound X. Let's assume as a catalyst for some chemical reaction A.
The claim is, however, not limited to that particular use. In fact, the claim gives absolute product protection, also covering other uses. For instance as a catalyst for another chemical reaction B for which compound X may be no good. Can an opponent use this in some way for an inventive step under current EPO case law, e.g. by filing evidence that compound X is not effective as a catalyst for chemical reaction B (assuming that chemical reactions B and A are very different from each other)?
Decision T 0128/82 appears to indicate that such an attack does not work under the case law of the BoA.
The decision is about first medical use claims, but that should not distract us now.
The Board in T0128/82: "the practice of the European Patent Office hitherto has shown that substance and medical preparation claims for therapeutically active compounds not limited to specific indications are allowed, even though as a rule only certain specific activities are stipulated. "

So, to rephrase: the practice of the EPO then was [and still is] that product claims for compounds having some medical activity are allowed, these claims not being limited to specific uses, even though as a rule only one or few specific medical uses are taught in the description.
As far as I know, the above statement is still the EPO's practice, and equally in non-medical fields of chemistry. Hence, the practice of the EPO is that product (substance, composition) claims are allowed, these claims affording absolute product protection not limited to a specific use, even though as a rule only one or few uses of the product are taught in the description.
The relevant national German decision is Disiloxan, BGHZ 51, 378 (1969) on p.8, which indicates that the Kongorot decision of 20.031889 is to be followed (Patentblatt 1889, issue 19, page 209, available at the DPMA here. ).
Also relevant is T 181/82, about the inventive step of a pure compound claim, stating that "An effect which may be said to be unexpected can be regarded as an indication of inventive step", the effect at issue was obtained when the claimed compounds were used as light stabilisers as was taught in the description.

In other words, no patentability objection can be raised solely on the ground that a product claim covers any use whereas the description teaches only one use.

Absolute product protection has been controversial in the past, somewhat recently for genes, and further back in history for chemical compounds in general. See, generally, R. Uhrich, Stoffschutz, 2010 (critical), available open access since 2020 under DOI 10.1628/978-3-16-159918-7.

The link to the decision is provided after the jump, as well as (an extract of) the text of the decision.

Rent Agreement Format