"Consisting Essentially Of" Precludes Infringement; Recapture Requires an Objective Review of Surrendered Matter

Kim v. ConAgra Foods, Inc. (05-1414) September 20, 2006

Yon Ja Kim, holder of reissue patent Re. 36,355 appealed the district court’s JMOL judgment of noninfringement of claim 5 and its dependent claims and claim 10 in favor of ConAgra Foods, Inc. The court also considered ConAgra's cross-appeal which asserted that the patent was invalid.

The patent in this case related generally to breadmaking, and specifically to oxidizing agents used during the breadmaking process to strengthen dough, increase loaf volume, contribute to fine crumb grain, and increase shelf life. Claim 5 of the patent read as follows:

Claim 5. A potassium bromate replacer composition consisting essentially of, by weight:

(a) about 0.001 to 0.03 parts ascorbic acid as an oxidant per 100 parts flour,

(b) about 0.015 to 0.2 parts food acid per 100 parts flour, said food acid selected from the group consisting of acetic acid, citric acid, fumaric acid, lactic acid, malic acid, oxalic acid, phosphoric acid, succinic acid, tartaric acid, fruit juice, fruit juice concentrate, vinegar, wine, and mixtures thereof, and

(c) flour.

Kim contends that the jury charge rested on an incorrect construction of the phrase "[a] potassium bromate replacer composition" in both claims 5 and 10 of the ’355 patent. Kim conceded that "potassium bromate replacer" is a claim limitation, but argued that a "potassium bromate replacer" is simply a "potassium bromate substitute," which she in turns describes as a composition that is present when potassium bromate is not.

The district court concluded, after reviewing the specification, that in order to infringe, the bread must (a) contain the ingredients in the proportions recited in the claims, and (b) the ingredients "must perform essentially the same function in the production of that bread as would potassium bromate." The Federal Circuit agreed with the district court, noting that the specification makes clear that the claimed potassium bromate replacer is an oxidizing agent and, as such, must carry with it the associated functional elements (strengthening the dough, increasing loaf volume, etc.).

On the issue of infringement, the Federal Circuit found that the addition of the term "consisting essentially of" was detrimental to the finding of infringement:

Since the accused products included the same ingredients as the patented composition, Kim simply assumed that they had the same effects on dough as did the patented composition.

However, with respect to a "consisting essentially of" claim, there is no infringement where the accused product contains additional, unclaimed ingredients that materially affect the basic and novel properties of the invention. See PPG Indus. v. Guardian Indus. Corp., 156 F.3d 1351, 1354 (Fed. Cir. 1998). Here, ConAgra’s 7-Grain and Whole Wheat products contained additional ingredients beyond ascorbic and food acids, such as vital wheat gluten, ferrous sulfate, and dough strengthening enzymes.

ConAgra agrued that these additional ingredients materially affected functionality. Kim argued that they did not. However, during trial, Kim did not support this conclusion with any examinations or tests of the actual accused products. Under these circumstance, the Federal Circuit concluded that Kim did not prove infringement.

Incidentally, the transitional phrase "consisting essentially of" replaced "comprising" during prosecution via Examiner's Amendment to overcome prior art so the case would be allowed.

ConAgra further alleged that Kim's reissue patent was invalid for violating the recapture rule. The reissue procedure allows a patentee to broaden the scope of an existing patent to include subject matter that had been erroneously excluded from that patent. However, the recapture rule prevents a patentee from regaining through reissue the subject matter that he surrendered in an effort to obtain allowance of the original claims.

The court looked at Federal Circuit precedence that was cited to suggest that recapture required a subjective review of the surrendered subject matter (i.e., a "deliberate decision to surrender specific subject matter" and "intentionally omitting or abandoning" the claimed subject matter). The court ruled that subjective tests were not applicable in this regard:

It is clear that in determining whether "surrender" of subject matter has occurred, the proper inquiry is whether an objective observer viewing the prosecution history would conclude that the purpose of the patentee’s amendment or argument was to overcome prior art and secure the patent. This is because the recapture rule is aimed at ensuring that the public can rely on a patentee’s admission during prosecution of an original patent . . . Thus, if the objective public observer can discern a surrender of subject matter during the prosecution of an original patent in order to overcome prior art and obtain the patent, then the recapture rule should prevent the reissuing of that patent to claim the surrendered subject matter.

Under this analysis, the court found that, after viewing the prosecution history, the broadened claims did not violate the recapture rule (although it appears under the subjective test they would have).

Dissent (Schall): Judge Schall provided an interesting dissent on claim interpretation, finding that the language of the specification and the prosecution history clearly showed that the patentee acted as her own lexicographer in defining what "potassium bromate replacer" meant, and under Phillips, that definition should govern ("[o]ur cases recognize that the specification may reveal a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess. In such cases, the inventor’s lexicography governs.")

Without exception, the patentee consistently defined "potassium bromate replacer" as "a slow acting oxidant that is functional throughout the entire manufacturing process" throughout the specification and prosecution. Judge Schall found this a compelling reaon to dissent, and hold that the lower court's judgment should be vacated and remanded under his claim construction.

In the majority opinion, the court pointed out that "[n]either party urged this construction in the district court or in this court. While we may have the authority to adopt claim constructions which have not been proposed by either party . . . we should be hesitant to do so."