Tate & Lyle v Roquette Frères: meticulous verbal analysis?

The IPKat has been pondering the Court of Appeal judgment in Tate &Lyle Technology Ltd v Roquette Frères [2010] EWCA Civ 1049 for a little while now, after noticing it issuing last week.  This related to an appeal by Roquette Frères from the judgment of Mr Justice Lewison in the High Court in June 2009, on which the IPKat commented at the time here.  What he found most interesting the first time round was the reference to the 17th century French playwright Molière, which nicely illustrated a point about inherent anticipation (read the judgment for more details).  The point of interest this time round, however, was a little different.

As a reminder, the case related to European patent EP0905138, granted to Roquette Frères in 2002.  The patent described processes for synthesising a sugar substitute maltitol by hydrogenation of maltose.  A key feature of the patent was that a known by-product of the hydrogenation process, maltotriitol, was found (surprisingly, of course) to affect the crystal formation of the resulting maltitol.  At low maltotriitol concentrations, a bipyramidal crystal form would tend to result, while at higher concentrations a prismatic form would instead result.  Controlling the type and proportion of these crystal forms could be useful in affecting how the resulting product behaved, such as in terms of its flow behaviour.  The patent was granted with 10 claims but, after opposition, only one claim was left, being:

"The use of maltotriitol to modify or control the form of maltitol crystals."

At first instance, the judge found that the claimed invention was invalid for a number of reasons, one being that it lacked novelty over a prior disclosed process involving hydrogenation of maltose, in which maltotriitol would inevitably modify or control the form of maltitol crystals.  Did this mean that the prior art disclosed the use of maltotriitol to modify or control the form of the resulting maltitol crystals?  The judge effectively held that it did, after construing the words of the claim (in particular those in italics).  The issue on appeal was then principally one of construction.  Did the wording of the claim, taken in context, mean that it was merely describing what was already known (or at least inherent), or would a skilled reader understand the invention to be something different and new? 

As might be expected at this point, a familiar old chestnut from Catnic Components v Hill & Smith [1982] RPC 183 was wheeled out, by reference to the more recent case of Virgin Atlantic Airways Ltd v Premium Aircraft Interiors UK Ltd [2009] EWCA Civ 1062.  The relevant part of Lord Diplock's judgment in Catnic reads:

"A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge."

After paying due attention to this, Lord Justice Lloyd then proceeded to do, as far as the IPKat can see, precisely the kind of meticulous verbal analysis warned against by Lord Diplock.  Alternative meanings of the words "use", "control" and "modify" were analysed.  Paragraph 47 is a particular corker of obfuscatory verbosity:

"Mr Purvis' point that on the judge's construction the patent is self-defeating, so to speak, has some force. Such a situation is not what the skilled reader would expect. However, while avoiding the danger of being over-technical and semantic, the skilled reader has to read the language of the patent in a fair way, having regard to all of its contents. He might well be led by [0034] to expect that the claim would involve changing the level of maltotriitol. The claim does not use the word "vary", however, and although "modify" is a synonym for "vary", "control" is not necessarily so. What he finds is that, first, "control" is spoken of at [0035] as covering several different types of process, carried out at different stages. Secondly, "control" of the maltotriose content is referred to at [0047], in relation to adjusting the maltotriose content, and specifically in relation to the form of the eventual crystals. Then, at [0059], reference is again made to the maltotriose content, and to it being "controlled", that is to say being reduced (depleted) to a greater or lesser extent "or not at all". Next, at [0071] to [0074], four different versions of the process are explained, of which one occurs before hydrogenation (thus, in relation to maltotriose, not to maltotriitol) and one does not involve any adjustment of the level of maltotriitol. Lastly, when he comes to the one and only illustrative example of the invention, at [0076] to [0077], no adjustment is mentioned at all."

To cut a long story short, as far as the IPKat understands it the issue was whether the claim required a deliberate modification of the maltotriitol content in order to vary the crystal forms in the resulting maltitol.  Lord Justice Lloyd, with whom the other Lords Justice agreed, found that it did not in light of what was disclosed in the rest of the specification.  So, in a very roundabout way, a meaning of the claim was arrived at that agreed with that of the judge.  The appeal was dismissed.

The IPKat is unsure what, if anything, to make of this judgment.  It is hardly a model of clarity, but he suspects there is an important core meaning in there somewhere, if only he could get to it.