Posted: August 15th, 2018
The UK Court of Appeal has considered the validity of a patent claiming a particular composition of glass fibres.
OCV’s patent claimed glass strands with constituents expressed as a percentage by weight (e.g. SiO2 at 58-63%, Al2O3 at 12-20%). Further, the composition required the ratio of CaO to MgO to be less than or equal to 2, and the sum of Al2O3, MgO and Li2O to be at least 23% of the total weight. In total, the patent specified thirteen such ranges for the various compounds (or ratios of compounds).
Jushi relied on a single piece of prior art, a US patent referred to as “Neely”. The composition of Neely glass was similarly described using constituents expressed as a percentage by weight (e.g. SiO2 at 55-61%, Al2O3 at 12-18%). Neely defined seven numerical ranges which were either the same or fell entirely within the ranges claimed by the patent and a further six ranges which overlapped with those claimed by the patent. The question before the Court was whether the ranges disclosed in Neely were novelty destroying.
In the court of first instance (IPEC) HHJ Hacon made reference to the Technical Board of Appeal decisions T 26/85 TOSHIBA/Thickness of Magnetic Layers  and T 666/89 UNILEVLER/Washing Composition  and applied the EPO’s “serious contemplation” test to the facts at hand.
The test was applied despite the reservations expressed by Lord Justice Floyd in the Patents Court decision H. Lundbeck A/S v Norpharma SpA . Ultimately, HHJ Hacon was not satisfied that a skilled person would seriously contemplate making glass fibres according to the teaching of Neely within the area of overlap and therefore the patent was not anticipated by the prior art.
Lord Justice Floyd provided the leading judgment of the Court of Appeal. He reiterated his reservations concerning the serious contemplation test and explained that he would take issue with the EPO if the serious contemplation test was “intended to relax the rigor of the general law of novelty”. Floyd LJ preferred to follow the conventional approach utilised in Synthon’s Patent  and Dr Reddy’s Laboratories (UK) Ltd v Eli Lilly and Co Ltd  and held that the simple question is whether the prior art contains a disclosure of the invention. The answer will depend on how the prior art document would be understood by the skilled person, taking account of the common general knowledge.
Jushi argued that Neely disclosed a “compositional space” in which the skilled person would understand that any combination of values within the various ranges may be chosen – each and every combination of values is therefore disclosed and at least a fraction of these will fall within the claims of the patent.
Floyd LJ rejected this argument for a number of reasons including the fact that it contradicted with the teaching of Dr Reddy’s Laboratories: a broad generic disclosure in prior art does not take away the novelty of a claimed more specific one. Floyd LJ held that there was nothing in Neely teaching the skilled person that they should operate in the area of combined overlap of the numerical ranges; the invention claimed by the patent remained hidden in the disclosure of Neely. Accordingly, Floyd LJ concluded that the patent was not anticipated.
A copy of the decision can be read here.
Headnote: Tom Taylor, Marks & Clerk Solicitors