In the recent decision of Universal Polymers Pty Ltd v Greenzone Pest Innovations Pty Ltd [2020] APO 37, the Australian Patent Office found claims which focus on manufacturing parameter ranges, such as temperature, pressure and so on, may still be found to have an inventive step. We explain this decision in further detail below.
Background
Greenzone filed a patent application relating to a construction element for forming an expansion joint which acts as a physical and chemical insect barrier. The construction element comprises a polymeric foam containing at least one insecticide substantially distributed throughout the polymeric foam with the claims reciting particular characteristics of the polymeric foam. Universal Polymer opposed patent grant.
In an interim decision, the delegate found that all claims lacked inventive step in view of evidence including a prior publication D2. Greenzone amended its claims to include the following feature of the polymeric foam:
wherein the polymeric foam is manufactured at a temperature of less than 180°C and is prepared primarily from a blend of cross-linked polyethylene and a low melting ethylene-vinyl acetate (EVA) copolymer.
The Opposition proceeded to final determination with the only real question being whether the manufacturing temperature of the polymeric foam could provide the claims with an inventive step. It is worth noting that, in many cases, a temperature limitation would not be considered inventive.
Law on Inventive Step
After stating the well-known test for inventive step:
“The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not.”
Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd (1981) 148 CLR 262, 286 (Aickin J), the delegate went on to consider inventive step of the insect barrier with a specific polymeric foam manufactured at a temperature below 180°C.
Discussion
The Opponent put its argument of lack of inventive step on three bases:
- the material selection and manufacturing temperature was obvious in view of D2 and common general knowledge
- a 180°C manufacturing temperature had no technical effect and was an arbitrary selection
- where bifenthrin was used as insecticide, it would be obvious to manufacture the polymeric foam below a temperature, 180°C, at which it was known to degrade.
Not Obvious in View of Common General Knowledge
The Opponent did prove that blending of linear low-density polyethylene and low melting EVA polymer was routine before the priority date. However, the evidence did not show that the specifically claimed blend of cross-linked polymer and a low melting EVA copolymer manufactured at less than 180°C was part of common general knowledge before the priority date.
Not Obvious in View of D2 and Common General Knowledge
When regard was had to D2, this document taught a range of combinations and permutations under the broad principle of manufacturing a foam sheet including an insecticide ingredient. While true that D2 disclosed processing temperature at least 210°C, and in some cases as high as 240°C, this was by way of example. Such disclosure did not amount to teaching away from manufacturing a polymeric foam at less than 180°C. Yet it also would not directly lead the skilled person, as a matter of course, to try manufacturing a blend of cross-linked polyethylene and a low melting EVA copolymer at a temperature of less than 180°C in the expectation that it might well produce a useful result.
Temperature Limitation Has a Technical Effect
The Opponent had also argued that the 180°C manufacturing temperature limitation failed to achieve a technical effect and was an arbitrary selection. This argument was rejected. The specification made clear that there was a non-arbitrary purpose in the carefully selected density, manufacturing temperature and material choice that were part of the invention.
The description explained that addition of low melting point EVA keeps the extrusion temperature below approximately 180°C which helps in the dispersion and melt mixing of the polymer and insecticide. The description also explained that 180°C is important because active ingredient bifenthrin degrades at higher temperatures. There was a technical effect.
Obvious in View of Bifenthrin Selection
The Opponent had argued that, having identified that bifenthrin degrades above 180°C, the skilled person would find it obvious to manufacture at less than this temperature to avoid degradation. However, there was no evidence that the common general knowledge included knowledge that material containing bifenthrin was to be manufactured at less than 180°C so as to avoid/reduce thermal decomposition or volatilisation during the formulation of the claimed polymeric foam material.
The amended claims were found to have an inventive step.
Takeaways
Claims which focus on manufacturing parameter ranges, such as temperature, pressure and so on, may still be found to have an inventive step. The specification should clearly identify the technical advantages of selecting the value of the claimed parameter range. A good understanding of the prior art that demonstrates the selected parameter value is not already known is also a helpful input to the drafting process as it may tend to demonstrate advantages and suggest other advantages that had not been appreciated in the prior art. Describing these advantages will definitely lower the temperature in an inventive step controversy.