by Dennis Crouch Obviousness is the central doctrine of patent law. It is both the most common reason for rejection and often the most complicated issue because of both factual and legal complexities. The new Chemours Co. decision provides an important addition to obviousness doctrine in two areas: (1) teaching away; and (2) commercial success. The majority sided with the patentee and reversed the IPR Boardâs single-reference obviousness determination. The dissent argued that the opinion gives too much power to the teaching-away doctrine. Chemours Company v. Daikin Industries (Fed. Cir. 2021) Chemours is a 2015 spin-off from Du Pont. Its patents at issues here relate to a polymer having a high melt flow to allow high-speed extrusion to cover electrical wires. U.S. Patent Nos. 7,122,609 and 8,076,431. The claims require a standardized melt flow rate range: 30±3 g/10 min along with other physical properties.