Best Mode Patent-Raptor Claims Another Victim in Wellman

By Eric Guttag
May 6, 2011

Last year, I reported on the “best mode” Patent-Raptor of 35 U.S.C. § 112, first paragraph, in Ajinomoto Co., Inc. v. International Trade Commission. See Best Mode Patent-Raptor Devours Another Victim in Ajinomoto. I also remarked that, like the Jurassic Park film franchise, we would probably have sequels for this stealthy and certainly ravenous patentivour. How right I was. The latest sequel happened late last month in Wellman, Inc. v. Eastman Chemical Company where the “best mode” Patent-Raptor claimed yet another victim.

The victim (or actually victims) in Wellman were U.S. Pat. No. 7,094,863 (the ‘863 patent) and U.S. Pat. No. 7,129,317 (the ‘317 patent) which were collectively referred to as the “Wellman patents.” The Wellman patents relate to polyethylene terephthalate (“PET”) resins useful for making plastic beverage containers. More specifically, the Wellman patents described “slow-crystallizing” PET resins the retained clarity in these beverage containers when “hot-filled” with product. By the time the ‘317 patent was filed in May 2004, Wellman had commercialized a slow-crystallizing PET resin known as Ti818, which was not disclosed in the patents in a deliberate attempt to retain a trade secret.

By the time of commercialization, Ti818 had the following composition:

This recipe for Ti818 was not disclosed in the Wellman patents. In fact, the Wellman patents simply described concentrations and concentration ranges for categorized lists of possible ingredients, including the amounts of isophthalic acid and diethylene glycol used in these PET resins, which didn’t encompass the amounts listed in the above Table.

Most significantly, the Wellman patents described optional heat-up rate (“HUR”) additives for these PET resins, stating that the “natural spinels and synthetic spinels” (e.g., copper chromite black spinel and chrome iron nickel black spinel) were the “most preferred” HUR additives. Carbon-based HUR additives, such as carbon black (see Carbon-Black reheat agent listed in the above Table), were described in the Wellman patents as being “suitable” and noted that another patent (the Pengilly patent) disclosed “satisfactory” carbon black HUR additives. The Pengilly patent disclosed preferred particle sizes for carbon black in the range of from about 15 to about 30 nm. By contrast, the Ti818 recipe included a HUR additive called N990, a specific type of carbon back having a larger particle size of 290 nm.

Adding to the “problematic” disclosure of what the Wellman inventors considered the “best mode” for these HUR additives were the three provisional applications that were filed. Two provisional applications leading to the Wellman patents filed in May 21, 2003 and April 6, 2004 characterized the carbon-based HUR additives as “preferabl[e]” and the copper chromite spinels as “suitable.” On May 20, 2004, a third provisional application (leading to the ‘317 patent) was filed and which changed the preference for the HUR additives from carbon-based to the spinels.

Wellman alleged that Eastman Chemical infringed several claims of the ‘863 patent, as well as the ‘317 patent. Most (but not all) of the asserted claims of the ‘863 and ‘317 patents would have encompassed the Ti818 recipe. Those claims encompassing the Ti818 recipe were ruled by the district court (on summary judgment) to be invalid for violating the “best mode” requirement. (The district court also ruled that all of the asserted claims of the Wellman patent were invalid under 35 U.S.C. § 112, second paragraph, as being indefinite, a ruling that was overturned by the Federal Circuit in the subsequent appeal.)

Most damaging on the “best mode” issue for Wellman was testimony from the inventors. The district court found that at least one inventor (Dr. Nichols) viewed the Ti818 recipe as the “best mode” for practicing the invention of the Wellman patents. The district also found that another inventor (David Thompson) preferred carbon black N990 as the HUR additive. While acknowledging that “ranges of ingredients encompassing the best mode” can satisfy this requirement, “the [Wellman] patents disguise Ti818 by disclosing ‘preferred’ ranges of certain ingredients that do not encompass the actual concentrations of those ingredients in the Ti818 formula.” Ouch!

Even more damaging was the reason the district court found for these omissions of the ingredients in the Ti818 recipe. Specifically, the district court found that, based on the testimony of inventor Thompson, and his supervisor (James Bruening), Wellman “sought to maintain the use of N990 as a trade secret.” Such testimony from the inventor (and other personnel of the patentee) is the ultimate “ouch” when a “best mode” violation is asserted to have occurred. (In fact, this deliberate omission of N990 appears to be much more egregious than the omission found to have occurred in the Ajinomoto case).

Chief Judge Rader writing for the Federal Circuit panel affirmed the district court’s “best mode” invalidity ruling. As described by Chief Judge Rader, the “best mode” requirement has two prongs: (1) at the time of the patent filing, did the inventor possess a “best mode” for practicing the claimed invention?; and (2) if there was a “best mode,” did the inventor “conceal” it from the public? (Chief Judge Rader’s opinion also observed that, while the district court hadn’t construed the claims before the “best mode” inquiry, that didn’t matter because the district court had limited its best mode ruling to the uncontroverted claims.)

Regarding the first prong (possession of the “best mode”), Chief Judge Rader noted that there was “no genuine dispute that at least one inventor subjectively believed that Ti818-which contains carbon black N990-was the best resin available for hot-fill packaging at the time” at the time the Wellman patents were filed. And Chief Judge Rader found that the “applicant did not” disclose the Ti818 recipe believed by the inventors to be the “best mode.” Chief Judge Rader also noted there was some confusion by inventor Nichols as to which Ti818 recipe was preferred (the 2003 or 2004 recipe for Ti818), but that didn’t “rescue the relevant claims from a best mode violation.” In fact, it actually showed that the inventor Nichols “had an obligation to disclose the recipe he believed to be the best mode at the time of patent filing-the 2003 recipe.”

Chief Judge Rader’s opinion also noted that “an evolving recipe potentially means that the inventors had no best mode of practicing the invention,” citing the 1998 case of Bruning v. Hirose. This was with reference to whether there was a significant change between the 2003 and 2004 recipe for Ti818. But Chief Judge Rader stated that “this evidence cannot overcome the testimony of the inventors” regarding their “subjective belief that the 2003 recipe of Ti818 was the best method of practicing the invention at the time of filing,” particularly with reference to the N990 carbon black HUR additive used in that 2003 recipe. That meant the first prong (possession) for a “best mode” violation had been satisfied.

Regarding the second prong (concealment of the “best mode”), Chief Judge Rader confirmed the chilling finding by the district court that this N990 carbon black was not disclosed in the Wellman patents because “Wellman chose to protect this ingredient as a trade secret.” In fact, Chief Judge Rader’s opinion observed that Wellman “continued to protect the use of N990 in its PET resin products as a trade secret from its discovery in 2002 through February of 2010.”

Possibly recognizing that it was in serious trouble on the second (concealment) prong, Wellman tried to raise doubt as to whether N990 was truly the “best mode” by referring to other experimental work allegedly showing that the spinel HUR additives disclosed in the Wellman patents were superior the carbon black HUR additives. But Chief Judge Rader found that the significance this alleged experimental work on the “best mode” issue was not raised before the district court. Put differently, Chief Judge Rader appears to have viewed the effort by Wellman to assert this alleged experimental work as “belated excuse.”

In further support of “concealment” prong, Chief Judge Rader also noted that the Wellman patents “do not expressly disclose the Ti818 recipe, but instead describe many possible ingredients with varied ranges of concentrations.” While noting that the “best mode” may be represented by disclosing ranges, Chief Judge Rader also pointed to the fact that some of the ingredients for the Ti818 recipe, specifically the amounts of isophthalic acid and diethylene glycol,” “fall outside of the disclosed preferred ranges and therefore lead away from the Ti818 recipe.” Chief Judge Rader also observed that the Wellman patents “lead away from the use of carbon black N990 in Ti818” by characterizing carbon black as merely a “suitable” HUR additive. In fact, Chief Judge Rader further observed that, while the Wellman patents disclose carbon black HUR additives have “typical” particle sizes of from 10 to 100 nm (preferably from about 15 to about 30 nm), the particle size for the preferred carbon black N990 (290 nm) was, again, outside the ranges disclosed in the Wellman patents.

Chief Judge Rader even went on examine whether the disclosure in the Wellman patents would enable one skilled in the art to “practice the best mode without undue experimentation.” But Chief Judge Rader noted that another inventor (Dr. Schiavone) “admitted he would not derive the recipe for Ti818” from what was disclosed in the Wellman patents. While inventor Nichols also testified that “a series of design experiment could be developed to identify a resin meeting the claimed invention,” he “did not state that those experiments would yield Ti818. That, along with a record showing intentional concealment by Wellman of the “best mode,” sealed satisfaction of the second “concealment” prong as far as Chief Judge Rader was concerned: “By masking what at least one inventor considered the best of these slow-crystallizing resins, Wellman effectively concealed its recipe for Ti818.”

What is startling about Wellman is how the patentee put the ‘863 and ‘317 patents squarely in the path of the “best mode” Patent-Raptor by deliberately keeping the Ti818 recipe a trade secret. As I’ve instructed numerous clients, you have a clear choice on “best mode” issue: (1) disclose the “best mode” and file the patent; or (2) don’t file the patent if you want to keep the “best mode” as a trade secret. There is simply no “in between” on this issue. The only question now is whether the Tyrannosaurus Rex of patent law (inequitable conduct) will devour what is left of the Wellman patents.

*© 2011 Eric W. Guttag

The Author

Eric Guttag

Eric Guttag  
Mr. Guttag has over 38 years of corporate and private intellectual property law experience on patent, trademark, copyright, trade secret and unfair competition matters, computer and Internet law, including patent application drafting, prosecution, and patentability studies; infringement and validity studies; international patent prosecution; patent and know-how licensing; consulting, confidentiality, clinical study and research agreements; trademark searches and opinions; trademark registration and prosecution; trademark freedom-to-use studies and trademark litigation and dispute resolution.

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Discuss this

There are currently 3 Comments comments.

  1. Paul F. Morgan May 8, 2011 9:26 pm

    The pending patent reform bill will expressly eliminate “best mode” as a litigation defense, but will NOT eliminate its requirement in 35 USC 112.
    [So, will some future litigation defendant still be able to argue that intentional non-disclosure of the best mode of making the patented item [especially if it is the only commercially desirable mode and being maintained as a trade secret] is inequitable conduct?]

  2. EG May 9, 2011 10:49 am


    Very true. I find the so-called “patent law reform” legislation bizarre in dealing with the “best mode” issue. Making “best mode” a requirement but providing for no explicit recourse if violated (especially if knowlingly and deliberately violated) is illogical to me. From what I’ve seen in the commentary, there’s a real question whether the proposed legislation would even allow assertions of IC as a defense to such violations. Frankly, I see the “best mode” requirement as being part of the quid pro quo, so I’ve got no issue with such a requirement, provided the requirement is reasonable (i.e., punishes only knowing and deliberate violations).

  3. Paul F. Morgan May 9, 2011 12:42 pm

    Thanks EG.
    Some research I did on “best mode” case law some years ago indicated that there was no significant problem with “best mode” issues litigation burdens back when it was limited to what was being claimed, and to deliberate or intentional concealment. But then some subsequent Fed. Cir. panel decisions [ignoring their own rule of stare decisis for their own prior decisions, as they often do] created much broader and much more ambigous “best mode” defenses case law. That lead to “best mode” discovery harrasment becoming a significant litigation burden, even though rarely successful, which lead to an NSF recomendation to kill it, which in turn lead to this draft legislation.