E.I. DuPont de Nemours v. Synvina C.V. On September 17, 2018, the Federal Circuit reversed the PTAB’s decision that DuPont failed to prove by preponderant evidence that Synvina’s patent would have been obvious at the time of the invention.  The court found that Dupont met its burden of preponderant evidence when it presented prior art that taught ranges that overlapped with the claimed air pressure and temperature ranges.  The court ruled that the PTAB erred in failing to shift the burden to Synvina after Dupont presented this evidence, stating, “where there is a range disclosed in the prior art, and the claimed invention falls within that range, the burden of production falls upon the patentee to come forward with evidence of teaching away, unexpected results or criticality, or other pertinent objective indicia indicating that the overlapping range would not have been obvious in light of that prior art.”