Wooly invalid patent

So, this is probably not a very good pun to start a new year with; but you have to admit that there are no easy puns with mineral wool, which was the subject-matter of today’s patent – a patent which was found to lack inventive step by Board of appeal 3.3.05.

The problem and solution approach is a must for any inventive step reasoning at the EPO. The first step of this approach consists in determining the closest prior art.

However, practically speaking, it is also very useful to run the approach backwards: if, as the patentee, you realize that, starting from prior art document A, it is much easier to arrive at a conclusion of non-obviousness than starting from prior art document B, then you know you need to push for the selection of A as the closest prior art, and thus come up with arguments disqualifying B. Of course, the opposite is true if you are an opponent.

One strategy sometimes used by patentees to get around a prior art reference which would make their lives miserable if selected as the closest prior art is to explain that this prior art reference is not a realistic starting point for the skilled person.

A typical example of a document which would not be a realistic starting point is one which has a lot of features in common with the claimed invention, but in a different context. As stated e.g. in T 870/96, the closest prior art should be a document

which [the] skilled person would have realistically taken under the “circumstances” of the claimed invention insofar as these circumstances can be retrieved in one item of the prior art. Consequently, among these “circumstances”, aspects as the designation of the subject matter of the invention, the formulation of the original problem and the intended use and the effects to be obtained should generally be given more weight than the maximum number of identical technical features (reasons, 4.1).

Now, in today’s decision T 2579/11, inventive step of the opposed patent had to be assessed in view in particular of two relatively similar prior art references, documents A5 and A6. These prior art references were in fact similar for a good reason: A5 was the priority document of patent application A6.

The patentee argued that the closest prior art was A6 and not the priority document A5. It is straightforward to guess why the patentee made such a submission: the claimed invention related to a mineral wool comprising a number of compounds within specific concentration ranges or concentration ratios. Both A5 and A6 disclosed mineral wools containing the same compounds as the claimed invention. But the examples disclosed in A6 differed from those of A5. In examples 2 and 5 of A5, only the concentration ratio MgO/CaO was outside of the claimed range. In contrast, in some of the examples of A6, not only was the MgO/CaO ratio outside of the claimed range, but in addition the alumine content was above the claimed maximum threshold. Or, in other examples, the alumine content was within the claimed range but then the MgO/CaO ratio was further away from the claimed values than in examples 2 and 5 of A5.

As a result, it was easier to arrive at a finding of lack of inventive step starting from A5 than starting from A6, since fewer modifications needed to be made starting from A5.

Artificial sheep from which mineral wool can be sheared
Artificial sheep from which mineral wool can be sheared

In order to try to disqualify A5 as the closest prior art, the patentee offered the following argumentation:

A5 is accessible only in the examination file wrapper of A6. The skilled person has no reason to start from priority document A5 since he/she has a more elaborate text available, which was filed after one year of additional research. The fact that examples 2 and 5 of A5 were not included in A6 shows that they were not valid examples. Therefore, document A6 is the closest prior art (facts and submissions, VII).

But this did not fly with the Board. The Board first of all noted that both A5 and A6 had the same purpose (which was also the purpose of the claimed invention), namely providing mineral wool which can be dissolved in a physiological medium, and which can be fibered by centrifugation (reasons, 2.2.5). Second of all, in terms of features in common with the claimed invention, it was concluded that, for the reasons already set forth above, “the wools according to examples 2 and 5 of A5 request fewer structural modifications than the wools of A6” (reasons, 2.2.6).

Finally, the Board addressed the patent proprietor’s argumentation as follows:

Once a priority document has been made accessible to the public, it belongs to the state of the art under article 54(1)(2) EPC like any other publicly available document. The papers of a patent application on the one hand and a priority document on the other hand are then entirely distinct documents, even if the latter is made accessible to the public through the publication of this application. The fact that a later application generally has a more detailed description than the priority application can therefore not, by itself, justify that the priority document should be discarded in favor of the later application when the closest prior art is selected. The fact that an embodiment and/or an example contained in the priority application are not included in the application claiming the priority does not by itself allow one to conclude that such embodiment and/or example were less preferred, or less valid. 

[…] Even assuming that the later application A6 contains results of complementary research, nothing indicates that examples 2 and 5 of A5 which are not included in A6 would be invalid or of poor quality or insufficiently disclosed (reasons, 2.2.7).

Thus, examples 2 and 5 of A5 were deemed to represent the closest prior art, and the rest of the problem and solution approach analysis led the Board to the revocation of the patent due to lack of inventive step.

To some extent, it seems to me that a parallel could be made with other cases such as T 741/91 or  T 334/92, where an old prior art document was rejected as a candidate closest prior art because said document had been ignored in the relevant field and had not given rise to further development.

Here, the priority document A5 was dated at most one year prior to the subsequent application A6, so this was not a very”old” document by any means. But the common trait is that, in both situations, an argument was made that a prior art reference should be disregarded as the closest prior art, not because of its intrinsic contents, but rather because of extrinsic evidence that the reference would not count in the eyes of the skilled person. In T 2579/11 the argument failed, whereas it succeeded in T 741/91 or T 334/92. This may just be a matter of the extrinsic evidence being persuasive enough or not.

As a side remark on a procedural aspect of the present decision, the Board skipped the novelty objections and only took position on inventive step as this was sufficient to reach the conclusion that the patent should be revoked. Similarly, the Board focused on inventive step of the most restricted claims defended by the patent proprietor, namely auxiliary request No.3, the conclusion on this request also applying to the previous, broader requests.

This is a reminder that Boards of appeal have a lot of leeway for dealing with submissions of the parties in the order that they see fit, and for getting to the final decision in the most efficient manner. However, shortcuts such as the present one may seem somewhat unorthodox. In particular, there was an objection of lack of novelty of the main request and the first auxiliary request over A5 (as well as over another document A3). This means that the Board decided that these requests involved no inventive step over A5 without ruling whether the claims at stake were even novel over A5.

CASE REFERENCE: Board of Appeal 3.3.05, T 2579/11, Laine minérale / Saint-Gobain, March 10, 2015

One K.O. for Kao

As a present to priority nerds, and probably a punishment to others, here is another post on the burning issue of partial priority.

In a previous post, I attempted to provide some practical tips to patent drafters anxious about the outcome of the referral to the Enlarged Board of Appeal on the issue of poisonous (or toxic, whichever you like best) divisionals. As was recalled in this post, the issue boils down to how partial priority is assessed: under what we could call a “broad” or “generous” interpretation of partial priority, any generalized claim can partly benefit from the priority of a partial original disclosure, and thus be immune to anticipation by any poisonous divisional, poisonous parent or any other poisonous you-name-it family member; if, however, one believes that partial priority requires certain specific conditions in order to be acknowledged (let’s call this the “narrow” or “strict” interpretation), then generalized claims which do not pass the test (whatever it is) may be prone to some kind of incestuous anticipation.

Several boards of appeal adopted the strict interpretation of partial priority, whereas Board 3.3.07 preferred the broad and generous interpretation, notably in decision T 1222/11. This is the divergence in case law which led to the referral to the Enlarged Board.

Today, I would like to focus on this decision T 1222/11 in more detail: not so much on the (very interesting) obiter part of the ruling where the Board discusses in detail why they believe the strict interpretation put forward by other boards is wrong; but rather on the rest of the decision, which should not be ignored and is very informative indeed.

Oh – and did I forget to mention it? In this ex parte case T 1222/11, the patent application died in the end. It did not die because of a toxic divisional though, as Board 3.3.07 does not believe in toxic divisionals – and as this was not an issue anyway. But it died all right, and because of an invalid priority claim.

With this in mind, is it possible that the broad and generous interpretation might not be so generous after all with applicants and patent proprietors? At any rate it is certainly worth having a closer look at what exactly went wrong in T 1222/11 for the applicant Kao Corporation, and how they were unfortunately K.O.-ed.

In the case at hand, the application claimed the priority of a Japanese patent application, and the text of the application as filed was identical to the English translation of this Japanese patent application (reasons, 7).

But there was also an earlier PCT application by the same applicant, D4b, with a similar disclosure. In particular, D4b included several examples falling within the scope of the claims of the application at stake.

According to Kao, since D4b was only intermediate prior art under Article 54(3) EPC, it was possible to introduce a disclaimer into the main claim, more precisely a G 1/03-type undisclosed disclaimer, so as to restore novelty over D4b. Various formulations for the disclaimer were put forward as a main request and auxiliary requests.

This line of defense by the applicant was based on the presupposition that the priority claim of the application was valid.

If however the priority claim was in fact invalid, then D4b became full prior art under Article 54(2) EPC, as a result of which the introduction of an undisclosed disclaimer to restore novelty over D4b was no longer permitted, in view of the conditions set forth in G 1/03.

This is why the Board examined the validity of the priority claim, focusing on the fact that

According to Article 87(1) EPC, a requirement for enjoying a right of priority for filing a European patent application is that the application for a patent […] on the basis of which the priority is claimed must be the first application in respect of the same invention (reasons, 7).

The Board therefore compared the teaching of the priority document with that of the earlier application D4b by the same applicant. The Board explained that, if the earlier application D4b related to the same invention as the Japanese priority document, then said Japanese priority document could not be considered as a “first application” and thus the priority claim was invalid.

As a side note, the applicant could not possibly rely on the mechanism of Article 87(4) EPC, per which

a subsequent application in respect of the same subject-matter as a previous first application and filed in or for the same State shall be considered as the first application for the purposes of determining priority, provided that, at the date of filing the subsequent application, the previous application has been withdrawn, abandoned or refused, without being open to public inspection and without leaving any rights outstanding, and has not served as a basis for claiming a right of priority.

Indeed, D4b had been published and (if only for this reason) could not be considered as having been merely replaced by the later Japanese application.

Let’s now go back to the comparison between the priority document (substantially identical to the application at stake) and the earlier application D4b. The priority document, just like the claimed invention itself, was directed to a leave-on hair cosmetic composition containing an organic dicarboxylic acid (A) and an organic solvent (B), and further characterized by a certain pH and a certain buffering capacity. The Board first of all noted that 6 examples of compositions in D4b fell within the scope of claim 1 – these were the formulations that the applicant tried to exclude from the application at stake by way of a disclaimer. In addition, there were many more similarities between the priority document and D4b, including in terms of preferred components.

Only the buffering capacity was not explicitly recited in D4b, but for the Board, this parameter was simply a consequence of the other technical features present in D4b.

This finding meant that the priority document related to the same invention as D4b – and therefore the priority claim was invalid.

A patent attorney before and after application of a leave-on hair cosmetic composition
A patent attorney before and after application of a leave-on hair cosmetic composition

One aspect was more particularly discussed by the applicant, namely the fact that D4b was limited to the use of a combination of malic acid and lactic acid as component (A), whereas the priority document and the claimed invention were not.

According to the Board, this

does not mean that D4b  and the present application do not contain a common subject-matter or invention, but only means that the disclosure of D4b does not extend to the use of malic acid without any lactic acid. In other words, the present subject-matter can be seen as the invention of D4b supplemented with additional subject-matter relating to the use of malic acid without lactic acid (reasons, 9.4).

To put it differently, the priority document as well as the claimed invention were generalized relative to the subject-matter of the earlier application D4b.

But, despite such generalization, both the priority document / the application and D4b were found to relate to the same invention. This is made quite clear in the other following statements by the Board:

It follows from the above that the combination of features defined in positive terms in the first part of present claim 1 of the Main Request cannot be distinguished from the disclosure of the earlier application D4b. Example Products 10 to 14 and Example Product 6 of D4b constitute prior disclosures of the combination of features defined in positive terms in the first part of present claim 1 of the Main Request and therefore cannot be held to relate to a different subject-matter, i.e. a different invention (reasons, 9.2)

It must be concluded […] that the Appellants cannot benefit from the priority claimed for the combination of features defined in positive terms in amended claim 1, in so far as it covers subject-matter disclosed in D4b, in particular in so far as it covers the six compositions disclosed in D4b which the Appellants are seeking to disclaim (reasons, 10).

Further down in the decision, in the obiter dictum on partial priority, the Board explains that it is sufficient for the purpose of benefiting from partial priority if alternative subject-matters in a broad claim can be conceptually identified – a very undemanding requirement.

The Board further notes that this

also implies in view of the necessary coherence of rules of law on the subject of claiming priority defined in the EPC, that when an application on the basis of which a priority date is claimed encompasses a narrower subject-matter already disclosed by the same applicant in an earlier application, the decision on whether the claim to priority on the basis of the later application is valid does not depend on whether the narrower subject-matter disclosed in the earlier application is identified in said later application. The latter situation is precisely the one underlying the case under appeal (reasons, 11.8).

The bottom line of this rationale is that, when two successive applications are filed by a same applicant, the second one having a broader subject-matter than the first one, then the second application can never be used to claim priority for a (yet) subsequent filing – unless use is made of the special provisions of Article 87(4) EPC, i.e. the first application is nipped in the bud.

Logically, one should reach the opposite conclusion if the “narrow” interpretation of partial priority advocated by the other, poisonous divisionals-friendly boards, is used.

So, the “broad” interpretation may save a number of patents from the unpleasant agony of being poisoned by another member of their family; but it may also toll the bell for some applicants who like to file successive applications for relatively similar subject-matters, and possibly broaden the definition of their inventions over time, starting from specific examples.

Thus, whatever the outcome of the pending referral is, it seems that extreme caution will still be required for properly claiming priority.


CASE REFERENCE: Board of Appeal 3.3.07, T 1222/11, Kao Corporation, December 4, 2012

Poison and antidote

Poisonous or toxic divisionals have been a somewhat exotic but much commented upon topic, that has led to the revocation of a handful of patents in the past few years.

The excitement and dread generated in the European patent profession will culminate when the Enlarged Board of Appeal of the EPO, to which the topic has recently been referred, issues its decision G 1/15, probably within the next couple of years.

It looks like most, if not all, of the profession hopes that the Enlarged Board will put an end to a theory which is often viewed as nonsensical. I am not sure that I concur with this unanimity. But what everyone will agree on is that there is no predicting with absolute certainty what the Board will have to say on this subject.

So, since the world will not stop turning and patent applications will not stop being filed while we are all waiting for the verdict of the wise people in Munich, it may be worth looking for an antidote to the poison.

To put it more simply, today’s question is whether there is a way to immunize newly filed patent applications against a possible “poisonous divisional” objection further down the road, in case the Enlarged Board does not dispel this objection as being rubbish.

In order to answer this question, we need to look more closely at what the problem really is about. This is where the notion of “partial priority” comes into play.

Let’s assume a first application A, and a subsequent European application B claiming the priority of A. Let’s also assume that the invention claimed in B is broader than what was originally disclosed in A. For example A discloses a process with a temperature in the range of 10-100°C, whereas a broader range of 5-500°C is claimed in B. Or A discloses an apparatus comprising one part soldered to another part, whereas B claims the same apparatus wherein the two parts are attached to each other by any possible means.

In such scenarios, quite clearly, the B claims do not fully benefit from the priority of A, since B does not relate to the same “subject-matter” as A (in accordance with opinion G 2/98).  The tricky issue is whether the priority claim is fully invalid or whether it is only partially invalid.

If the priority is held fully invalid, and if A is a European patent application which gets to be published (in principle after the filing date of B), then A becomes prior art under art.54(3) EPC, i.e. prior art for the purposes of the assessment of novelty only (not inventive step). Therefore, if A discloses one or more embodiments falling within the scope of the B claims, these claims are invalid. We could call this a “toxic priority” situation.

Moreover, even if A itself is not prior art, for instance because it never gets published, or because it is not a European patent application, the existence of a divisional application C stemming from B can also be prejudicial to the novelty of B. Indeed, the part of C which does benefit from the priority of A can be opposed to B for the purposes of novelty only. In such as case, the divisional application is said to be toxic to the parent. But the reverse is also true, and the parent B could be toxic to its child C.

One solution which has been proposed to get out of this mess is the notion of partial priority.

If we accept that the claimed subject-matter in B can be divided up into two parts, a first part that benefits from the priority of A and a second part that does not benefit from the priority of A, then an argument can be made that:

  • said first part is immune to any toxicity because it benefits from the earliest filing date in the family; and
  • said second part is also immune, because it is not disclosed in A, so that there can be no anticipation by A (or any other application in the family validly claiming the priority of A).
Can a poison container safely be generalized to a beverage container without losing the priority for the poison embodiment?
Can a poison container safely be generalized to a beverage container without losing the priority for the poison embodiment?

Whether and to which extent partial priority can be conjured up is one of the main questions that the Enlarged Board of Appeal has to deal with in G 1/15 (see the referral decision T 557/13). In the founding opinion on priority G 2/98 it was mentioned that “the use of a generic term or formula in a claim for which multiple priorities are claimed […] is perfectly acceptable […] provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters”. There has been a debate as to what this exactly means, and whether this implies restrictions on the conditions under which partial priority in a generic claim can be acknowledged.

With all this in mind, and without being able to guess at the further guidance which the Enlarged Board will offer, it is reasonable to state that there is a risk of invalidation when a European application is filed:

  • which claims a priority,
  • which comprises claims that have been generalized relative to the teaching of the priority document,
  • if the priority document is a European patent application which gets to be published, or if one or more divisional applications are filed at any point of time.

But, oddly enough, there are instances in which more poison could lead to a cure.

In fact, one solution when the above risk is identified at the time of drafting a priority-claiming application consists in adding a fallback position containing a feature which is not disclosed at all in the priority document. Indeed, if the priority claim becomes invalid because of an added feature (as opposed to just because of a generalization), then there can be no anticipation by the priority document or by any parent or divisional application – since the added feature restores novelty over those. Ideally, the added feature should be minimal and not significantly affect the scope of protection. Remember: it is only necessary to restore novelty over a potential art.54(3) EPC disclosure, so inventive step is not at stake.

If we go back to the above examples, if A discloses a process with a temperature in the range of 10-100°C, and if this range needs to be broadened to 5-500°C in B, why not also add in B another innocuous feature not at all disclosed in A, at least in a dependent claim? For instance, we could add that the process is performed within a time frame of 1 minute to 100 hours, if this is relevant.

Or, if A discloses an apparatus comprising one part soldered to another part, and if the claims in B need to be broadened to all possible modes of attachment between the parts, why not also add in a dependent claim in B reciting that the apparatus weighs from 100 g to 100 kg, assuming this is a relevant range.

Thus, even if partial priority is denied for the generalized claim, it is always possible to rely on the fallback and decide to completely forget about priority and at the same time make sure that there can be no anticipation by A or any application claiming the priority of A.

This suggestion comes with two caveats, though.

The first caveat is that, in case any other relevant disclosure took place during the priority year, the complete loss of the priority date may not be an option. In that case, the only solution seems to go back to what was originally disclosed in the priority document A and stick to that.

The second caveat is that features to be added in the second filing B should be as innocuous as possible (in order not to significant restrict the scope of protection); but not completely meaningless. Indeed, meaningless limitations would not be enough to distinguish over an art.54(3) disclosure, bearing in mind that the disclosure has to be read and assessed by the skilled person. For instance, if A discloses an invention on a car, and if we decide to add in B that the car has four wheels, it is very possible that the skilled person will be deemed to understand the car of A as necessarily comprising four wheels, in which case we would be back to square one.

CASE REFERENCE: Board of Appeal 3.3.06, T 557/13, Infineum USA LP v. Clariant Produkte (Deutschland) GmbH, July 17, 2015