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Claims Invalidated Because Specification Does Not Set Forth the Best Mode as Contemplated by at Least One of the Inventors

10-1249
April 29, 2011

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Last Month at the Federal Circuit - May 2011

Judges: Rader (author), Lourie, Whyte (sitting by designation)

[Appealed from: D. Del., Judge Robinson]

In Wellman, Inc. v. Eastman Chemical Co., No. 10-1249 (Fed. Cir. Apr. 29, 2011), the Federal Circuit affirmed the district court’s grant of SJ, holding that all but five of the asserted claims of U.S. Patent Nos. 7,129,317 (“the ’317 patent”) and 7,094,863 (“the ’863 patent”) (collectively “the Wellman patents”) were invalid for failing to disclose the best mode.  In addition, the Federal Circuit reversed the district court’s grant of SJ, holding that the asserted claims of the Wellman patents were invalid for indefiniteness.  The Federal Circuit remanded for further proceedings.   

Wellman, Inc. (“Wellman”) brought suit against Eastman Chemical Company (“Eastman”), alleging infringement of the Wellman patents.  The Wellman patents are directed towards “slow crystallizing” polyethylene terephthalate (“PET”) resins for use in plastic beverage containers.  Wellman had commercialized a “slow-crystallizing” PET resin called Ti818 by the time Wellman filed the application leading to the ’317 patent in May 2004.  The recipe for Ti818 was not disclosed in the Wellman patents, nor did the patents disclose any other specific PET resin recipes.  The Wellman patents did provide ranges of concentrations of possible ingredients.  However, the preferred ranges in the Wellman patents for isophthalic acid and diethylene glycol did not embrace the amounts of isophthalic acid and diethylene glycol contained in Ti818. 

The Wellman patents disclose optional heat-up rate (“HUR”) additives for the PET resin that improve the resin’s reheating profile during bottle blow molding.  Natural spinels and synthetic spinels are described in the Wellman patents as the “most preferred” HUR additives.  In contrast, carbon-based HUR additives are described as “one embodiment” of the invention.  In addition, the Wellman patents state that “suitable” carbon-based additives include carbon black and that U.S. Patent No. 4,408,004 (“Pengilly”) discloses “satisfactory” carbon black HUR additives.  Pengilly teaches a preferred average particle size for carbon black in a range of between about 15 to about 30 nm.   Notably, Ti818 includes a carbon black additive called N990, which is a specific type of carbon black with a 290 nm particle size.

On Eastman’s motion for SJ, the district court held that all of the asserted claims, except for five claims that Wellman contends do not encompass Ti818, were invalid for failing to disclose the best mode.  The district court also held that the claims were invalid for indefiniteness. 

On appeal, the Federal Circuit affirmed the district court’s grant of SJ for failure to set forth the best mode of practicing the claimed invention and reversed the district court’s grant of SJ for indefiniteness.  With respect to best mode, the Federal Circuit noted that usually the best mode inquiry begins by construing the claims.  However, that was not necessary here because the parties disputed only whether five claims of the Wellman patents encompass Ti818—the parties agreed that the remainder of the asserted claims encompass Ti818—and the district court had limited its best mode holding to the uncontroverted claims.

Second, if the inventor has a subjective preference for one mode over all others, the Federal Circuit must then determine whether the inventor “concealed” the preferred mode from the public.  The second prong inquires into the inventor’s disclosure of the best mode and the adequacy of that disclosure to enable one of ordinary skill in the art to practice that part of the invention.  This second inquiry is objective, depending on the scope of the claimed invention and the level of skill in the relevant art. 

The best mode inquiry requires the Federal Circuit to first subjectively determine whether, at the time of patent filing, the inventor possessed a best mode of practicing the claimed invention based on the inventor’s personal preferences as of the application’s filing date.  With respect to this first prong, the Federal Circuit stated that there was no genuine dispute that at least one inventor subjectively believed that Ti818 was the best resin available for hot-fill packaging at the time the Wellman patents were filed.    The Federal Circuit also noted that the record indicated that different recipes for Ti818 had been tested up to May 2004, and that “an evolving recipe potentially means that the inventors had no best mode of practicing the invention,” but concluded that “[s]ubtle changes in the recipe in 2004 to accommodate specific customer demands does not excuse the applicant’s obligation to disclose what Dr. Nichols—and every other inventor—contemplated was the best mode of practicing the invention at the time of filing.”  Slip op. at 12.  

The Federal Circuit also found that there was no genuine dispute that at least one inventor subjectively believed that the specific HUR additive used in Ti818, carbon black N990, was essential.  Although after testing, one inventor indicated a clear preference for carbon black N990 with a particular particle size, Wellman did not disclose carbon black N990 in its patent applications.  Instead, Wellman chose to protect this ingredient as a trade secret.  In fact, Wellman continued to protect the use of N990 in its PET resin products as a trade secret from its discovery in 2002 through February 2010 and requested that the district court seal the courtroom during the arguments on SJ expressly to maintain the confidentiality of N990. 

Notwithstanding these admissions, Wellman argued that experimental work created a genuine dispute of material fact as to whether the inventors believed that carbon black N990 was the most preferred HUR additive at the time of filing.  The Federal Circuit though found that Wellman’s arguments had both procedural and substantive shortcomings.  With respect to procedure, the significance of the data in the Wellman patents had not been raised before the district court, so the Federal Circuit held that Wellman forfeited the right to argue its significance on appeal.  With respect to substance, the Federal Circuit stated that the data did not compare the appropriate PET recipes and that the testimony regarding the inventor’s preference at the time of filing was undermined by the disclosed preferred embodiment and Wellman’s contemporaneous internal documents clearly praising carbon black N990.  Thus, the Federal Circuit concluded that at least one inventor possessed a subjective preference for Ti818 and at least one inventor possessed a subjective preference for carbon black N990 at the date of filing.

Next, because the inventors had a subjective preference for one mode over all others, the Federal Circuit turned to the second prong of the best mode inquiry—whether there was any issue of material fact concerning concealment of the best mode.  The objective second prong inquires into the inventor’s disclosure of the best mode and the adequacy of that disclosure to enable one of ordinary skill in the art to practice that part of the invention.  The Federal Circuit found that “[w]hile there is no requirement under 35 U.S.C. § 112 ¶ 1 to identify which disclosed mode is the best mode, and best mode may be represented by a preferred range of conditions or groups of ingredients, Wellman concealed the best mode by not disclosing the recipe for Ti818, by identifying preferred concentration ranges for certain ingredients that excluded those used in Ti818, and by identifying preferred particles sizes for the HUR additive other than that used in Ti818.”  Id. at 17-18 (citations omitted).

Despite these facts, the Federal Circuit also went on to examine Wellman’s disclosure to discern whether it enabled a person of skill in the art to practice the best mode without undue experimentation.  The Federal Circuit noted that one inventor admitted that he could not derive the recipe for Ti818 from the disclosure in the Wellman patents.  Further, while this inventor testified that a series of design experiments could be developed to identify a resin meeting the claimed limitations, he did not state that those experiments would yield Ti818.  The Federal Circuit concluded that by masking what at least one inventor considered the best of these slow-crystallizing resins, Wellman effectively concealed its recipe for Ti818.    

Lastly, the Federal Circuit found that Wellman intentionally concealed the best mode, because Wellman chose to maintain N990 as a trade secret.  Invalidation based on a best mode violation requires that the inventor knew of and intentionally concealed a better mode than was disclosed.  Thus, the Federal Circuit affirmed the invalidity of all but five of the asserted claims of the Wellman patents for failure to comply with the best mode requirement.   

With respect to indefiniteness, the Federal Circuit found that the district court erred in concluding that the Wellman patents do not provide sufficient guidance for construing the TCH claim term.  TCH is the temperature at which the sample crystallizes the fastest during heating in a differential scanning calorimetry (“DSC”) machine.  All of the claims asserted by Wellman contain a limitation to a PET resin having a certain TCH as measured by DSC.  The district court found that the Wellman patents do not disclose or suggest the desired moisture content for the claimed PET resins and that the Wellman patents are ambiguous as to whether the DSC measurement should be determined via a second scan or a first scan, even though both of these variations can affect TCH measurements.  The district court concluded that, given this “multitude of choices,” the TCH limitations in the asserted claims were not amenable to construction, rendering all of the asserted claims invalid as indefinite.

On appeal, the Federal Circuit disagreed.  The Federal Circuit first determined that the specifications of the Wellman patents support construing the TCH term to require testing of amorphous, not crystalline, PET material.  Second, the Federal Circuit addressed the lack of specific moisture conditions in the Wellman patents for DSC testing.  The Federal Circuit stated that well-known industry standards need not be repeated in a patent and, here, the record shows that a person of ordinary skill in the art in this field would follow standard industry guidance for moisture conditions of plastics for DSC.  Lastly, regarding whether the DSC measurement should be determined via a second scan or a first scan, the Federal Circuit found that a person of ordinary skill in the art would know when to use the results of a first scan and when to use the results of a second scan.  Thus, the Federal Circuit reversed the invalidity of the asserted claims for indefiniteness.

 

Summary authored by Marya K. Jones, Ph.D., student associate at Finnegan.