## Facts

- Atlas owned U.S. Patent No. 3,447,978 covering water-in-oil emulsion blasting agents used in industrial blasting.
- The patented compositions addressed limitations of prior blasting agents, including poor performance in wet conditions for ANFO-type mixtures.
- Atlas sued E.I. du Pont de Nemours & Co. and DuPont’s customer, Alamo Explosives Co., in the Northern District of Texas for infringing specified product claims and sought damages and injunctive relief.
- After a bench trial, the district court held the asserted claims not invalid under 35 U.S.C. §§ 102, 103, and 112, rejected allegations of fraudulent procurement, and found DuPont’s emulsion blasting products infringed.
- DuPont appealed, challenging enablement, anticipation, obviousness, enforceability based on alleged fraud/inequitable conduct, and infringement.

## Issues

1. Whether the patent’s specification enabled a person of ordinary skill to make and use the full scope of the asserted product claims without undue experimentation under 35 U.S.C. § 112.
2. Whether the asserted claims were anticipated under 35 U.S.C. § 102 or obvious under 35 U.S.C. § 103 in view of prior blasting-agent and emulsion references.
3. Whether uncited prior art before the Patent and Trademark Office reduces the statutory presumption of validity or lowers the challenger’s burden from clear and convincing evidence.
4. Whether the patent was unenforceable due to fraudulent procurement or inequitable conduct based on alleged nondisclosure of prior art.
5. Whether DuPont’s accused emulsion blasting agents met the limitations of the asserted product claims.

## Decision

- The Federal Circuit affirmed the judgment that the asserted claims were not invalid for lack of enablement, anticipation, or obviousness.
- The court affirmed rejection of the fraud/inequitable conduct defense and held the patent enforceable.
- The court affirmed the finding that DuPont’s accused emulsion blasting agents infringed the asserted product claims.
- The court held it was legal error to treat the presumption of validity as “weakened” so that invalidity could be shown by a mere preponderance when prior art was not cited to the PTO; the clear-and-convincing standard applies.

## Legal Principles

- Enablement requires a specification that teaches a skilled artisan to make and use the claimed invention without undue experimentation; some experimentation is permissible.
- Broad claims are not invalid merely because the specification does not enumerate every operable and inoperable variant; claims need not expressly exclude all potentially inoperative materials.
- The presence of some inoperative embodiments within the literal scope of a claim does not automatically render the claim non-enabled or invalid.
- Under 35 U.S.C. § 282, invalidity must be proven by clear and convincing evidence; uncited prior art may affect the weight of the evidence but does not lower the burden of proof.
- Inequitable conduct requires proof of both materiality and intent to deceive; failure to disclose prior art, without the required showing, does not make a patent unenforceable.

## Conclusion

The Federal Circuit upheld the patent’s validity and enforceability and affirmed infringement, emphasizing that enablement tolerates reasonable experimentation and that the statutory presumption of validity retains the clear-and-convincing standard even when some prior art was not before the PTO.


Atlas Powder Co. v. E.I. du Pont de Nemours & Co., 750 F.2d 1569 (Fed. Cir. 1984)