## Facts

- Kimberly-Clark (K-C) and Procter & Gamble (P&G) competed in disposable diapers and sought improved containment of infant bowel movements.
- In 1982, K-C employee Kenneth Enloe conceived adding stand-up elasticized barrier flaps inside the leg openings to reduce leakage.
- K-C obtained the Enloe patent; P&G later obtained the Lawson patent covering similar elasticized barrier-flap diaper features.
- K-C sued P&G for infringement of the Enloe patent and sought a declaration that Enloe had priority over Lawson; P&G contested priority and argued inventorship errors in the Lawson patent.
- P&G claimed Lawson’s patent should list Lawson, Blevins, and Buell as co-inventors and that earlier work by Buell (allegedly beginning in 1979) would move Lawson’s effective invention date earlier than Enloe’s.
- The district court found Enloe had priority and held specified Lawson claims invalid for lack of priority, found the Enloe patent neither invalid nor infringed, and found no inequitable conduct by K-C.
- While appeal and cross-appeal were pending, the parties entered a comprehensive settlement resolving the infringement dispute.

## Issues

1. Whether the post-trial settlement mooted the infringement controversy and required vacatur of the district court’s infringement determinations.
2. Whether the district court correctly found Enloe had priority over Lawson and invalidated overlapping Lawson claims on that basis.
3. Whether P&G could establish an earlier Lawson invention date by correcting inventorship to add co-inventors whose earlier work Lawson allegedly did not know about.
4. Whether the district court erred in finding no inequitable conduct in prosecution of the Enloe patent.

## Decision

- The Federal Circuit vacated as moot the portion of the district court judgment addressing infringement because settlement eliminated any live infringement controversy.
- The court affirmed the judgment that the Enloe patent had priority over the Lawson patent.
- The court affirmed invalidity (for lack of priority) of Lawson claims 1, 2, 4–7, 10–12, 14, 16, 19, 20, 23, 24, and 26.
- The court affirmed the finding of no inequitable conduct in procurement of the Enloe patent.
- The court declined to review validity issues concerning other Lawson claims that did not turn on priority relative to Enloe.

## Legal Principles

- A settlement that removes a live infringement controversy on appeal can render infringement issues moot, warranting vacatur of the infringement portion of the judgment while leaving collateral issues (e.g., priority, validity, inequitable conduct) for decision when they retain legal consequences.
- Patent priority between competing inventions depends on proven dates of conception and reduction to practice attributable to the relevant inventor(s) for the claimed subject matter.
- An inventor cannot use earlier work of others, unknown to the inventor, to establish joint inventorship or to obtain an earlier invention date for priority purposes; correction of inventorship cannot be used to back-date an independent inventor’s conception by “bootstrapping” unknown prior work.
- Inequitable conduct requires material misrepresentation or omission and specific intent to deceive; appellate review defers to the district court’s factual findings absent clear error.

## Conclusion

The Federal Circuit vacated the infringement rulings as moot after settlement, but affirmed that Enloe’s invention had priority over Lawson’s for overlapping subject matter, thereby invalidating the specified Lawson claims, and upheld the district court’s determination that the Enloe patent was not procured through inequitable conduct.


Kimberly-Clark Corp. v. Procter & Gamble Distrib. Co., 973 F.2d 911 (Fed. Cir. 1992)