Teaching away is an important concept when considering the obviousness of a patent claim. The Federal Circuit’s recent decision in Chemours v. Daikin makes it easier to find that a reference teaches away from an invention, potentially increasing the difficulty of invalidating a patent claim for being obvious. There, the Circuit reversed the Patent Trial and Appeal Board’s obviousness ruling, holding that it failed to adequately explain why a skilled artisan would modify a reference when doing so involved changing its inventive concept.
The patents in Chemours related to polymers used in insulating communication cables by pulling wires through melted polymer to coat and insulate wires – a process known as “extrusion.” Reference Kaulbach disclosed a melt flow rate of 24 g/10 min, while the claimed rate was 30 ±3 g/10 min. Notably, Kaulbach suggested having a “narrow” rather than a “broad” molecular weight distribution polymer, in contrast to the prior art. The Board found that a skilled artisan would have been motivated to increase the melt flow rate to be within the claimed range in order to coat wires faster. Continue Reading