Expert evidence of imaginative skilled person rejected

On September 5, 2014, Justice O’Keefe released his Reasons for Judgment in a patent infringement action between Dow Chemical and Nova Chemicals in relation to Canadian Patent No. 2,160,705. The 705 Patent generally relates to polyethylene films and products comprising a blend of homogeneously branched, substantially linear polymers (component A) and at least one heterogeneously branched interpolymer (component B). Dow had alleged that Nova’s SURPASS polyethylene composition infringed certain claims the 705 Patent.  Nova denied infringement and claimed that the asserted claims were invalid on a number of bases, including lack of utility, claims broader, anticipation, obviousness, double patenting and insufficiency of specification.

 Construction – “Comprising”

One issue raised for construction was the proper interpretation of the word “comprising”.  Dow alleged that the word, in the context of the patent and in its generally accepted meaning, means “including, but not limited to”.  Nova, on the other hand, proposed that comprising in the preamble of the asserted claims means “consisting of” but would have its conventional meaning of “including but not limited to” in claim 41.  Justice O’Keefe, following Boston Scientific and the expert evidence held that the meaning of a claim term must be the same within all claims and comprising should be construed to have its traditional meaning of “including but not limited to”.

Based on this construction, and after weighing the expert evidence, Justice O’Keefe held that NOVA’s SURPASS film infringed claims 11, 29, 30,33,35,36, 41 and 42  of the 705 Patent.

Promise of  the Patent

The description of the 705 Patent contains the following statement:

Surprisingly, we have now discovered compositions useful in films and molded parts having synergistically enhanced physical properties, which compositions comprise a blend of at least one homogeneously branched ethylene/α-olefin interpolymer and at least one heterogeneously branched ethylene/α-olefin interpolymer.

Nova alleged that by this statement he 705 Patent promised that all blends contemplated by the patent must exhibit a synergistically enhanced physical property. Dow submitted that this statement was not a promise and that the skilled person would not ascribe any particular meaning or importance to what it characterized as as passing comment.  Following Fournier Pharma and Bauer Hockey and after balancing the conflicting expert evidence, Justice O’Keefe concluded that the patent does not make an explicit promise of utility, such that the proper test is a “mere scintilla” of utility, which was met by the particular compositions claimed in 705 Patent.


One of Nova’s experts, during cross examination, confirmed that he was providing evidence through the experience of a skilled worker and that such a skilled worker would be expected to have an imagination. Justice O’Keefe held that the expert’s approach was not consistent with the description of the skilled person in Beloit Canada Ltd. v. Valmet Oy , namely that the skilled person has  “no scintilla of inventiveness or imagination”, and concluded that Nova’s expert had applied the wrong standard to his obviousness analysis.

After setting out the test set out by the Supreme Court of Canada in Sanofi-Synthelabo, Justice O’Keefe held that this was not a case in which an “obvious to try” analysis was warranted.  Nevertheless, Justice O’Keefe carried out the “obvious to try” analysis and concluded that the common general knowledge and prior knowledge did not make the invention self-evident such that Nova’s allegation of obviousness was not justified.

Justice O’Keefe rejected all of Nova’s other defences of invalidity and issued a declaration that Nova had infringed the asserted claims.

A copy of Justice O’Keefe’s Reasons for Judgement may be found here.