A+B = (drum roll…) C : Seeking patent protection for combinations of known elements

Often inventions involve a combination of known elements. In the textiles field, for example, this could involve combining a (known) weave pattern and a (known) compound yarn – if no-one has combined them before. When put together in a clever way, these can be patentable inventions. However, applicants must avoid certain pitfalls.

This article discusses how these inventions can be patented in Europe and/or the UK.

Key law

Before diving into the detail, it’s helpful to consider some quotes from the European Patent Office (EPO) and UK Intellectual Property Office (UK IPO):

A set of technical features is regarded as a combination of features if the functional interaction between the features achieves a combined technical effect which is different from, e.g. greater than, the sum of the technical effects of the individual features. In other words, the interactions of the individual features must produce a synergistic effect. If no such synergistic effect exists, there is no more than a mere aggregation of features.
- EPO Guidelines, March 2023 Ed., G-VII 7

It is sometimes thought that a patent may be saved from a finding of obviousness if a combination otherwise obvious has some unexpected advantage, and, in particular, an advantage caused by an unpredictable cooperation between the elements of the combination. I do not consider that such an approach is in general justified. There is a limited class of cases in which the patentee has identified an advantageous feature possessed by some members only of a class otherwise old or obvious, has described the advantageous effect in his specification and has limited his claim to the members of the class possessing this advantageous feature. Such a claim may be justified on the basis of what is called selection. Unexpected bonus effects not described in the specification cannot form the basis for a valid claim of this kind.
- Lab. Almirall v Boehringer Ingelheim [2009] EWHC 102 (Pat)

If a synergistic effect is to be relied on, it must be possessed by everything covered by the claim, and it must be described in the specification.
- Richardson-Vicks' Patent [1995] RPC 568

Those quotes highlight that for a combination of known elements to be recognised as not merely an obvious variant on what has gone before, and hence worthy of a patent, there needs to be some previously unrecognised advantage associated with the combination. At both the EPO and UK IPO, the assessment of non-obviousness of a combination of known elements turns on the interaction of the elements with each other. The standards applied by the EPO and UK IPO are similar to each other.

For a claim in a patent or patent application to be valid, it must claim at least one feature that is novel (different from the prior art) and inventive (not merely different, but non-obvious).

If one document in the prior art (the body of knowledge from prior to the effective date of the patent or application) discloses A; and another document in the prior art discloses B; but no document discloses A+B, then A+B is formally novel.

However, whether it is inventive (i.e. non-obvious) turns on the interaction between A and B.

A case study (in the textiles field)
Consider the example of a non-woven geotextile.

Erosion is a problem for manmade and natural structures alike. At the same time, in some eroded areas it is desirable to promote vegetation growth, as plant root systems can themselves provide an anti-erosive effect.

A coir mat is known as an anti-erosive structure. Meanwhile, ammonium nitrate is known as a fertiliser.

Simply impregnating coir with ammonium nitrate in order to obtain both the two independently known advantages is not inventive, and without any synergy, a patent claim directed to that combination may not (almost certainly, will not) succeed at the EPO or UK IPO.

However, if coir fibers are found to bind ammonium nitrate via an unexpected mechanism to form a slow-release fertiliser delivery system, which was previously unknown, this is a different and surprising advantage.

It then becomes important to consider how widely this invention could be defined. The unexpected advantage must be seen across the whole claim scope. Does the invention work with other nitrogenous fertilisers? What type of non-woven coir will work?

The reason to define the invention widely is to keep competitors at arm’s length, by making it harder to “work around” the claimed invention.

Once we have identified a reasonable scope across which the advantage lies, we have laid the groundwork for a variety of claims (at least to a product, kit of parts, method of manufacture, method of use; plus dependent claims i.e. narrower fall-back positions) to seek protection for the subject matter.

Let’s say that this advantage is found for all nitrogenous fertilisers, but only when coir is used, not when other matting is used.

Of course, in real life it can be very tricky to define sharp edges for what will/won’t have the advantage. Sometimes, there is no cliff in advantageousness, and/or there is no easy class definition for what will or won’t work.

It also depends on the availability of test results, as it is often unfeasible to test examples across the entire scope of a broad claim.

To give a practical steer: in the present case, it would help to have examples of structurally different nitrogenous fertilisers, in different amounts, with different coir depths; and comparative examples using non-nitrogenous fertilisers and non-coir matting.

Having more than one example is helpful, but hundreds (or even tens) are not necessary. It is helpful to have examples from different points along the claimed range and outside of it, e.g., to test coir depths of 0.2 mm, 5 mm, 10 mm, 40 mm and 55 mm if you’re planning to claim a range of 1-50 mm depth, to show values at different points in your range work, and values outside it don’t have the advantage. This helps with, e.g., an argument that too thin a layer releases the fertiliser too quickly, but too thick a layer only releases surface fertiliser and not fertiliser deeper in the coir, so that at neither extreme is an efficient slow-release advantage provided.

To summarise:
A new combination of known elements can be patented in the UK or Europe when there is a surprising new synergy between the items. Evidence will be needed to demonstrate that synergy exists and across what range of elements.

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