In re Dillon
Court of Appeals for the Federal Circuit
919 F.2d 688 (1990)
Relevant factsFree
Dillon (applicant) claimed tetra-orthoesters as fuel additives that reduce soot, while structurally similar tri-orthoesters were already known in the art as fuel additives for dewatering purposes; the examiner rejected the claims as obvious based on the structural similarity and existing use as a fuel additive, a three-judge Federal Circuit panel initially reversed, and the court granted rehearing en banc.
IssueFree
Whether, where a claimed compound has a similar structure but different use than a previously known compound, and that different use is not taught or suggested in the prior art, the claimed compound can still be subject to a determination of prima facie obviousness.