A divided panel of the U.S. Court of Appeals for the Federal Circuit reversed a claim construction ruling of the International Trade Commission (ITC), finding one sentence in a patent specification to be an express definition. Sinorgchem Co. v. U.S.I.T.C., Case No. 06-1633 (Fed. Cir., Dec. 21, 2007) (Dyk., J; Newman, J., dissenting).

Flexsys and Sinorgchem both produce a rubber antidegradant used in tires. Flexsys, the petitioner at the ITC, asserted that Sinorgchem infringed two Flexsys patents, which cover methods of producing the antidegradant and/or intermediate compounds. The two patents were related—one was a continuation-in-part of the other. After Flexsys prevailed before the ITC, Sinorgchem appealed.

Sinorgchem argued that the ITC’s construction of the claim term “controlled amount of protic material,” was error The common specification of the two patents stated that “[a] ‘controlled amount’ of protic material is an amount up to that which inhibits the reactions of aniline with nitrobenzene, e.g., up to about 4% [water] … when aniline is utilized as the solvent.” The specification also explained that the amount of protic material would vary based on different reaction conditions. The specification also contained an example that, when calculated using the information given, utilized over 10 percent water with aniline as a solvent.

Judge Dyk, writing for the majority, found that the specification had expressly defined a “controlled amount of protic material,” and that this express definition encompassed “up to about 4% [water] … when aniline is utilized as the solvent.” Accordingly, the majority limited the construed term in dispute (“controlled amount”) be limited to 4 percent.

Judge Newman dissented. She found no support for including the “up to about 4% water” in the claim construction of the term “controlled amount.” She accused the majority of improperly promoting “the number that is described for one condition, to a limit under all conditions, contrary to the specifications.” She noted that “the panel majority acknowledges that limits above 4% could be found in the specification … [but] discards this undisputed fact.”

Disclosure: The author of this case note represented Flexsys in this appeal.