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PTO’s Action Saves Patent from Invalidity

September 20, 2001
Williamson, John M.

Decision icon Decision

Last Month at the Federal Circuit - October 2001

Judges: Newman (author), Friedman, and Linn

In Exxon Corp. v. Phillips Petroleum Co., No. 00- 1173 (Fed. Cir. Sept. 20, 2001), the Federal Circuit reversed a district court’s grant of SJ of invalidity of U.S. Patent No. 5,324,800 (“the ‘800 patent”) and affirmed the court’s decision to strike “interference estoppel” as a defense to infringement.

Exxon Corporation’s (“Exxon”) ‘800 patent, directed to metallocene catalysts, issued from an application filed on August 30, 1991. This application, the fourth in a chain of continuing applications, claimed priority to three earlier filed applications and claimed an effective filing date of June 6, 1983.

Exxon’s European Patent Application, containing the same text as the ‘800 patent, was published on December 27, 1984. Phillips Petroleum Company (“Phillips”) moved for SJ of invalidity, arguing that under 35 U.S.C. § 102, due to a break in the chain of copending continuing applications, Exxon’s ‘800 patent is not entitled to a June 6, 1983, filing date. Thus, without the benefit of the June 6, 1983, filing date, the foreign publication renders the ‘800 patent invalid under 35 U.S.C. § 102(b).

The district court had granted Phillips’s motion for SJ of invalidity, finding a break in the chain of copendency between Exxon’s third and fourth applications. Exxon filed its fourth application as a continuation of its third application. However, Exxon instructed the PTO to cancel all claims of the prior application, leaving no claims in the fourth application as filed. Rather than follow Exxon’s instruction, the PTO retained claim 1 for filing purposes and cancelled the remainder of the claims in the fourth application. Exxon abandoned its third application before adding more claims to its fourth application. The district court had held that the PTO lacked authority to retain claim 1 for filing purposes and, therefore, the copendency between Exxon’s third and fourth applications was lost upon abandonment of the third application.

On appeal, Exxon argued that the PTO had acted within its administrative authority in preserving one claim for filing purposes. The Federal Circuit agreed, affording judicial deference to the PTO’s choice of procedures in the absence of a statutory or regulatory restraint on the PTO’s authority. After acknowledging several established procedures allowing the PTO to modify or ignore erroneous instructions from an applicant, the Federal Circuit specifically determined that the PTO is authorized to modify an applicant’s plainly incorrect instruction so that an application includes at least one claim in compliance with 35 U.S.C. § 112. Because the PTO’s action preserved the copendency between Exxon’s third and fourth applications, Exxon’s published foreign application does not serve as a § 102(b) invalidating reference. Accordingly, the Federal Circuit reversed the district court’s SJ grant of invalidity and remanded the case for further proceedings.

The Federal Circuit next considered Phillips’s conditional cross appeal regarding its interference estoppel defense. During an interference proceeding, the Examiner had designated certain of Exxon’s claims as subject to rejection if priority were lost as to the interference count. While the interference count was limited to unsubstituted metallocene catalysts, the designated claims covered both substituted and unsubstituted metallocene catalysts. Upon losing the interference, Exxon continued to prosecute only its claims directed to substituted metallocene catalysts. Phillips argued that because Exxon did not file a motion during the interference seeking the redesignation of its claims covering substituted metallocene catalysts, Exxon was estopped from continuing to prosecute these claims.

Observing that no court has ever recognized interference estoppel as a ground for patent invalidity and recognizing that the defenses of invalidity and unenforceability remain available to Phillips without inquiry into the interference procedure, the Federal Circuit affirmed the district court’s decision to strike the defense of interference estoppel.